CN117769068A

CN117769068A - Fabric-based laser-induced graphene electric heating flexible film, and preparation method and application thereof

Info

Publication number: CN117769068A
Application number: CN202410078978.3A
Authority: CN
Inventors: 罗斯达; 呼雅杰; 王冠韬; 高燕
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2024-01-19
Filing date: 2024-01-19
Publication date: 2024-03-26

Abstract

The invention provides a fabric-based laser-induced graphene electric heating flexible film, and a preparation method and application thereof, and belongs to the technical field of electric heating materials. The fabric-based laser-induced graphene electric heating flexible film comprises fabric-based laser-induced graphene, electrodes and a flexible packaging material, wherein the electrodes are arranged at two ends of the fabric-based laser-induced graphene, and the flexible packaging material is packaged on the upper surface and the lower surface of the fabric-based laser-induced graphene. The fabric-based laser-induced graphene electric heating flexible film provided by the invention is convenient for realizing large-area heating, and has the advantages of high heating rate, low cost, mild preparation environment, environment friendliness and no waste gas or sewage in the whole production process.

Description

Fabric-based laser-induced graphene electric heating flexible film, and preparation method and application thereof

Technical Field

The invention relates to the technical field of electric heating materials, in particular to a fabric-based laser-induced graphene electric heating flexible film, a preparation method and application thereof.

Background

The heating mode adopted by the existing electric heating equipment mainly comprises ceramic heating, electric heating wire (metal) heating and carbon-based heating film heating, wherein the ceramic heating is generally used for electric heating. The electric heating wires and the emerging carbon-based heating films become representatives of flexible electric heating equipment, wherein the heating area of the electric heating wires is filiform, the heating wires need to be repeatedly and spirally arranged when needing to be heated in a larger area, and the electric heating equipment obtained by the method has obvious trace and is uncomfortable to use; the carbon-based heating film existing in the market at present is generally formed by uniformly mixing and spin-coating graphene or graphene oxide and other materials with slurry, and the carbon-based heating film prepared by the method has high cost and low heating efficiency.

Disclosure of Invention

The invention aims to provide a fabric-based laser-induced graphene electric heating flexible film, and a preparation method and application thereof.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a fabric-based laser-induced graphene electric heating flexible film, which comprises fabric-based laser-induced graphene, electrodes and a flexible packaging material, wherein the electrodes are arranged at two ends of the fabric-based laser-induced graphene, and the flexible packaging material is packaged on the upper surface and the lower surface of the fabric-based laser-induced graphene.

Preferably, the number of pieces of the fabric-based laser-induced graphene in the fabric-based laser-induced graphene electric heating flexible film is more than or equal to 1, and when the number of pieces of the fabric-based laser-induced graphene in the fabric-based laser-induced graphene electric heating flexible film is more than 1, the fabric-based laser-induced graphene is paved on the same horizontal plane.

Preferably, when the number of pieces of the fabric-based laser-induced graphene in the fabric-based laser-induced graphene electric heating flexible film is greater than 1, the connection mode of an equivalent circuit formed by electrodes arranged on each fabric-based laser-induced graphene is serial, parallel or series-parallel.

Preferably, the method further comprises a male-female butt joint connector, wherein the male-female butt joint connector is used for performing expandable connection on at least one piece of fabric-based laser-induced graphene in the fabric-based laser-induced graphene electric heating flexible film and the rest of fabric-based laser-induced graphene.

Preferably, the fabric-based laser-induced graphene is obtained by performing laser-induced treatment on a fabric substrate; the fabric substrate comprises one or more of polyimide fabric, silk fabric, aramid fabric and cotton cloth.

Preferably, the flexible packaging material comprises one or more of a laminated PU cloth, a laminated TPU cloth, a PU film, a polyimide film, a hot melt cloth, a polydimethylsiloxane film, a polyurethane elastomer film and an epoxy resin prepreg.

The invention provides a preparation method of a fabric-based laser-induced graphene electric heating flexible film, which comprises the following steps:

and (3) laying or coating a preparation raw material of a flexible packaging material on the upper surface and the lower surface of the fabric-based laser-induced graphene connected with the electrode in a lamination manner, and packaging to obtain the fabric-based laser-induced graphene electric heating flexible film.

Preferably, when the fabric-based laser-induced graphene electrical heating flexible film includes a male-female butt connector, the preparation method of the fabric-based laser-induced graphene electrical heating flexible film includes:

Providing at least two unit modules, wherein each unit module is obtained by packaging at least one piece of fabric-based laser-induced graphene connected with an electrode and preparation raw materials of flexible packaging materials paved or coated on the upper surface and the lower surface of the laminate;

and carrying out extensible connection on each unit module by adopting the male and female butt connectors to obtain the fabric-based laser-induced graphene electric heating flexible film.

The invention provides an application of the fabric-based laser-induced graphene electric heating flexible film prepared by the technical scheme or the preparation method in preparation of electric heating equipment.

Preferably, the electrical heating device comprises a power source comprising a low voltage power source or a high voltage power source.

The invention provides a fabric-based laser-induced graphene electric heating flexible film, which comprises fabric-based laser-induced graphene, electrodes and a flexible packaging material, wherein the electrodes are arranged at two ends of the fabric-based laser-induced graphene, and the flexible packaging material is packaged on the upper surface and the lower surface of the fabric-based laser-induced graphene. The fabric-based laser-induced graphene electric heating flexible film provided by the invention is convenient for realizing large-area heating, and has the advantages of high heating rate, low cost, mild preparation environment, environment friendliness and no waste gas or sewage in the whole production process.

Drawings

FIG. 1 is a flow chart of the preparation of a fabric-based laser-induced graphene electrically heated flexible film according to the present invention;

fig. 2 is an XRD pattern, a raman spectrum, a laser power-resistance relationship chart, a scanning electron microscope chart and an EDS pattern of the fabric-based laser-induced graphene prepared in example 1;

FIG. 3 is a flow chart of the preparation of a large area, one piece LIGF electrically heated flexible film and an electrically heated IR chart of example 1;

FIG. 4 is a flow chart and sample diagram of the preparation of a large-area, multi-sheet parallel LIGF electrically heated flexible film according to example 2;

FIG. 5 is a circuit design diagram and an electrical heating infrared diagram of a plurality of parallel low voltage LIGF electrical heating flexible films and a LIGF size versus electrothermal temperature effect diagram of example 3;

FIG. 6 is a schematic diagram of a low voltage LIGF electrically heated flexible film with improved heating area and improved expandability by the parallel connection and addition of male and female mating connectors according to example 4;

FIG. 7 is a low voltage LIGF electrical heating flexible film material object diagram and an electrical heating infrared diagram of the multi-module series-parallel circuit of example 5;

FIG. 8 is an electrical heating infrared diagram of a sheet LIGF electrically heated flexible film with adjustable heating temperature and heating area of example 6;

FIG. 9 is a schematic diagram of bending heating of the LIGF electrically heated flexible film prepared in example 7;

FIG. 10 is an electrical heating performance test chart of the LIGF electrically heated flexible film prepared in example 8;

FIG. 11 is a physical image and an electrical heating infrared image of the LIGP electrically heated flexible film prepared in comparative example 1 and the LIGF electrically heated flexible film prepared in example 8;

FIG. 12 is a graph showing the results of the cyclic performance test of a sheet-type LIGF electrically heated flexible film prepared in example 9;

FIG. 13 is a graphical representation of LIGF electrically heated flexible films made from the different encapsulation materials of example 7.

Detailed Description

The fabric-based laser-induced graphene electrical heating flexible film provided by the invention comprises fabric-based laser-induced graphene (LIGF). In the invention, the Fabric-based laser-induced graphene is preferably obtained by performing laser-induced treatment on a Fabric substrate, wherein the Fabric substrate preferably comprises one or more of polyimide Fabric (PI Fabric), silk Fabric, aramid Fabric and cotton cloth, and more preferably is polyimide Fabric; the polyimide fabric preferably comprises polyimide cloth or polyimide felt. The invention prepares the fabric-based laser-induced graphene by adopting the fabric substrate through laser-induced treatment, and the regular braiding structure and the regular braiding gaps of the fabric-based laser-induced graphene provide sufficient space for the growth of the graphene, so that the graphene The uniform growth is carried out on the surface of the fabric, so that the continuous preparation with large area is realized; meanwhile, on the basis of meeting the preparation of large-area and large-scale uniform and smooth graphene fabrics, the pattern customization and the heating temperature individuation can be realized, and the uniformity, the flexibility and the reasonable distribution of electric energy of the fabric-based laser-induced graphene electric heating flexible film are improved; if a non-woven substrate, such as a paper-based material (polyimide paper), is adopted, a large amount of graphene growing in the process of large-area preparation (more than 25cm x 25 cm) forms extrusion due to the fact that the substrate is compact, so that the substrate is wrinkled, flatness is reduced, laser focal length is affected, uneven degree in the manufacturing process is increased, and large-area uniform preparation of the fabric-based laser-induced graphene electric heating flexible film is not facilitated. In the present invention, the gram weight of the polyimide fabric is preferably 70 to 500g/cm ² More preferably 72 to 200g/cm ² More preferably 74 to 100g/cm ² More preferably 75 to 85g/cm ² . In the present invention, the polyimide fabric is preferably woven from polyimide fibers, and the weaving method preferably includes a 2D weaving method, a 2.5D weaving method, or a 3D weaving method, and the 2D weaving method, the 2.5D weaving method, and the 3D weaving method independently include twist weaving, plain weaving, twill weaving, or thread weaving. In the present invention, the polyimide fiber is preferably obtained by spinning a polyamic acid (PAA) solution, and the concentration of the polyamic acid (PAA) solution and the specific operation conditions of spinning are not particularly limited, and may be any one known to those skilled in the art.

The invention preferably carries out laser induction treatment on the fabric substrate to obtain the fabric-based laser-induced graphene. The invention has no special limitation on the shape and the area of the fabric base material, and the shape and the area of the fabric base material can be determined according to actual needs, for example, the shape can be square, and the area is preferably less than or equal to 45 multiplied by 40cm ² More preferably 20 to 45X 20 to 40cm ² . In the invention, the laser used for the laser induction treatment is preferably an ultraviolet laser, a femtosecond laser, a fiber laser, a galvanometer laser or a carbon dioxide infrared laser; the fiber laserThe wavelength is preferably 1.06 μm; the wavelength of the galvanometer laser is preferably 1064nm or 532nm, and the galvanometer laser is suitable for preparing large-breadth fabric-based laser-induced graphene, for example, the preparation of the fabric-based laser-induced graphene with the area of 60cm multiplied by 60cm only needs about 7 min; the wavelength of the carbon dioxide infrared laser is preferably 9.3 μm or 10.6 μm, and the invention more preferably adopts a 10.6 μm carbon dioxide infrared laser; the rated power of the 10.6 μm carbon dioxide infrared laser is preferably 10 to 150W, more preferably 25 to 50W. In the laser induction treatment process, the scanning mode preferably comprises a vector scanning mode or a grating filling mode, and more preferably a vector scanning mode; the full load speed of the vector scan mode is preferably 254mm/s and the full load speed of the grating fill mode is preferably 254mm/s. The conditions of the laser induction treatment according to the invention include: the laser power is preferably not more than 25W, more preferably 0.5 to 25W, still more preferably 5 to 15W; the laser operation speed is preferably not more than 254mm/s, more preferably 50 to 220mm/s, still more preferably 50 to 200mm/s; preferably, the Pixel Per Inch (PPI) is equal to or less than 1000, more preferably 200 to 1000, still more preferably 500 to 1000; the laser defocus degree is preferably not more than 3.5mm, more preferably 1 to 3mm, and still more preferably 1.5 to 2.5mm. According to the invention, the carbonization degree of the fabric substrate can be regulated and controlled by regulating and controlling the parameters of laser induction treatment, so that the fabric-based laser-induced graphene with different resistances is obtained, and the heating characteristics of the fabric-based laser-induced graphene electric heating flexible film, such as the highest heating temperature and heating rate, can be regulated and controlled.

The fabric-based laser-induced graphene electric heating flexible film provided by the invention comprises electrodes, wherein the electrodes are arranged at two ends of the fabric-based laser-induced graphene. In the present invention, the electrode is preferably a copper electrode or an aluminum electrode, specifically, a copper foil conductive tape or an aluminum foil conductive tape may be attached to two ends of the fabric-based laser-induced graphene, or copper foil or aluminum foil may be printed on two ends of the fabric-based laser-induced graphene in a manner well known to those skilled in the art.

The fabric-based laser-induced graphene electric heating flexible film provided by the invention comprises a flexible packaging material, wherein the flexible packaging material is packaged on the upper surface and the lower surface of the fabric-based laser-induced graphene. The invention provides a packaging material arranged on the upper surface and the lower surface of the fabric-based laser-induced graphene, and the main purposes comprise: 1. the surface of the fabric-based laser-induced graphene is graphene, so that the fabric-based laser-induced graphene has conductivity, and the safety problems such as electric leakage and the like can be avoided by adopting the packaging material to package the fabric-based laser-induced graphene; 2. the packaging materials are arranged on the upper surface and the lower surface of the fabric-based laser-induced graphene, so that the stability of the structure (such as the washing and rubbing resistance) can be met; 3. different packaging materials have different thermal stability, but are generally lower than fabric-based laser-induced graphene, so that more high-temperature-resistant packaging materials are required to be used under higher use temperature requirements. In the present invention, the flexible sealing material preferably includes one or more of a laminated PU cloth (cloth formed by laminating a woven cloth with a PU film), a laminated TPU cloth (cloth formed by laminating a woven cloth with a TPU film), a PU film, a Polyimide (PI) film, a hot melt cloth, a Polydimethylsiloxane (PDMS) film, a polyurethane elastomer (ECO-Flex) film, and an epoxy resin prepreg, and the PU film preferably includes a TPU film. According to the invention, different flexible packaging materials are preferably selected according to actual use requirements, and the characteristics of each flexible packaging material are as follows:

When the laminated PU cloth is selected as the packaging material, the cloth in the laminated PU cloth is arranged on the outer side, and the PU film is arranged on the inner side, so that double-layer protection of the inner-layer PU film and the outer-layer cloth can be simultaneously provided for LIGF, the waterproof performance of LIGF is improved, and the rubbing resistance of LIGF is also improved. In the present invention, the thickness of the single-layer laminated PU cloth is preferably 0.5 to 3mm, more preferably 1.5mm. PU refers to polyurethane artificial leather, which is a polymer containing carbamate groups (-NH-COO-) in the molecular structure.

When the TPU fabric is selected as the packaging material, the fabric in the TPU fabric is specifically arranged on the outer side, and the TPU film is arranged on the inner side, so that double-layer protection of the inner-layer TPU film and the outer-layer fabric can be simultaneously provided for LIGF, the waterproof performance of LIGF is improved, and the rubbing resistance of LIGF is also improved. In the present invention, the thickness of the single-layer bonded TPU cloth is preferably 0.5 to 3mm, more preferably 1.5mm. The TPU in the invention specifically refers to thermoplastic polyurethane elastomer rubber, and is a polymer material formed by the joint reaction and polymerization of diisocyanate compounds (such as diphenylmethane diisocyanate (MDI) or Toluene Diisocyanate (TDI)) and macromolecular polyol and low-molecular polyol (chain extender).

When the PU film (further can be a TPU film) is used as a packaging material, the packaging material can provide better waterproof performance for LIGF, is soft as a whole, can be used as a small-area electric heating flexible film, but lacks certain rubbing resistance compared with the packaging material of TPU cloth. In the present invention, the thickness of the single layer of the PU film (further may be a TPU film) is preferably 0.1 to 3mm, more preferably 0.12 to 1mm, and still more preferably 0.15 to 0.5mm.

When the PI film is selected as the packaging material, the PI film itself is resistant to high temperature, so that the electric heating temperature of LIGF can be raised to 300 ℃, and the PI film has a certain flexibility although the PI film is made of a relatively hard material. In the present invention, the thickness of the PI film of a single layer is preferably 0.02 to 1.0mm, more preferably 0.03 to 0.5mm, and even more preferably 0.05mm.

When the hot-melt cloth is selected as the packaging material, the hot-melt cloth is not waterproof, so that the fabric-based laser-induced graphene electric heating flexible film using the hot-melt cloth as the packaging material does not have a waterproof function, but the addition of the hot-melt cloth improves the rubbing resistance of LIGF, and meanwhile, the hot-melt cloth has certain viscosity after being heated, so that LIGF can be adhered to any target heating area. The hot melt cloth is a hot melt adhesive net film containing TPU. In the invention, the gram weight of the hot melt cloth is preferably 15-50 g/cm ² More preferably 20 to 30g/cm ² Further preferably 25g/cm ² 。

When the PDMS film is used as the packaging material, the PDMS film can be stably used at the temperature of between 50 ℃ below zero and 200 ℃, has excellent waterproof, flexible and shearing resistance, and greatly improves the flexibility, shearing resistance and waterproof performance of the fabric-based laser-induced graphene electric heating flexible film. The PDMS film has good fluidity before solidification, can be coated according to the use requirement, for example, can be spin-coated or scraped film, and the thickness of the PDMS film can be controlled by regulating and controlling the operation parameters of equipment in the coating process. In the present invention, the thickness of the PDMS film is preferably 2 to 10mm, more preferably 2 to 5mm.

When ECO-Flex film is selected as the packaging material, the film has higher modulus, excellent tensile property and degradability. The ECO-Flex film has good fluidity before solidification, can be coated according to the use requirement, for example, can be specifically spin-coated or scraped film, and can be controlled in thickness by regulating the operation parameters of equipment in the coating process. In the present invention, the ECO-Flex film preferably has a thickness of 2 to 10mm, more preferably 2 to 5mm.

When the epoxy resin prepreg is selected as the packaging material, the epoxy resin prepreg has the characteristics of light weight and high strength. In the invention, the preparation raw material of the epoxy resin prepreg is specifically fiber reinforced epoxy resin prepreg, wherein the resin in the fiber reinforced epoxy resin prepreg is epoxy resin, and the fiber is preferably glass fiber or carbon fiber. In the present invention, the thickness of the single layer of the epoxy resin prepreg is preferably 0.025 to 2mm, more preferably 0.025 to 1mm.

Therefore, the reinforcing performance of different flexible packaging materials in the invention is different, and a single type of flexible packaging material or different types of flexible packaging materials can be selected and overlapped according to the use requirements of different application scenes, and specifically, the flexible packaging material can be a single PU film (further can be a TPU film), a hot melt cloth, a PI film, a PDMS film, an ECO-Flex film, an epoxy resin prepreg or a laminated TPU cloth, or can be compounded with the laminated TPU cloth, the TPU film and the hot melt cloth for use, and the specific description is given below.

In the present invention, when the flexible packaging material adopts a single PU film (may further be a TPU film), 1 to 10 layers are preferably laid, and specifically, 1 layer of PU film (may further be a TPU film) may be laid on each of the upper surface and the lower surface of the fabric-based laser-induced graphene in a lamination manner for packaging.

In the invention, when the flexible packaging material adopts a single hot-melt cloth, preferably 1-10 layers are paved, and specifically, 2 layers of hot-melt cloth can be respectively paved on the upper surface and the lower surface of the fabric-based laser-induced graphene in a lamination manner for packaging.

In the invention, when the flexible packaging material adopts a single PI film, 1-2 layers are preferably paved, and specifically, 1 layer of PI film can be respectively paved on the upper surface and the lower surface of the fabric-based laser-induced graphene in a lamination manner for packaging.

In the invention, when the flexible packaging material adopts a single PDMS film, specifically, the preparation raw material of PDMS is coated (preferably spin-coated) on the upper surface and the lower surface of the fabric-based laser-induced graphene, and the PDMS film is formed by curing.

In the invention, when the flexible packaging material adopts a single ECO-Flex film, specifically, the ECO-Flex preparation raw material is coated (preferably spin-coated) on the upper surface and the lower surface of the fabric-based laser-induced graphene and cured to form the ECO-Flex film as the flexible packaging material.

In the invention, when the flexible packaging material adopts a single epoxy resin prepreg, 1-2 layers are preferably paved, and specifically, 1 layer of epoxy resin prepreg can be respectively paved on the upper surface and the lower surface of the fabric-based laser-induced graphene in a laminated manner for packaging.

In the invention, when the flexible packaging material adopts a single TPU cloth, 1-2 layers are preferably paved, specifically, 1 layer of TPU cloth is respectively paved on the upper surface and the lower surface of the fabric base laser-induced graphene in a lamination mode, the fabric of the TPU cloth is arranged on the outer side, and the TPU film is in contact with the fabric base laser-induced graphene on the inner side, so that more supporting effects can be provided for the fabric base laser-induced graphene after heating and curing, and the protection of the fabric base laser-induced graphene surface graphene is realized. The fabric-based laser-induced graphene electric heating flexible film obtained by adopting the packaging mode has certain flexibility and surface insulation, can not resist washing and rubbing, and can be placed into a harder shell for use, for example: an electric heating towel rack, an electric heating meal heating plate, an instant water heater for hot drink, an electric heating lunch box or an electric heating cup pad.

According to the invention, when the flexible packaging material is compounded and used by adopting the TPU fabric, the TPU film and the hot melt fabric, specifically, 1 layer of hot melt fabric, 1 layer of TPU film and 1 layer of TPU fabric can be sequentially laminated and paved on the upper surface of the fabric-based laser-induced graphene, meanwhile, 1 layer of hot melt fabric, 1 layer of TPU film and 1 layer of TPU fabric are sequentially laminated and paved on the lower surface of the fabric-based laser-induced graphene, the fabric of the TPU fabric is arranged on the outer side, and the TPU film is in contact with the TPU film on the inner side. The fabric-based laser-induced graphene electric heating flexible film obtained by adopting the packaging mode is not water-washable but has better rub resistance, and can be used in a detachable liner or placed in a product which is not water-washable, such as: electrothermal carpets or electrothermal wall carpets.

According to the invention, when the flexible packaging material is compounded and used by adopting the TPU fabric, the TPU film and the hot melt fabric, specifically, 2 layers of hot melt fabric, 1 layer of TPU film and 1 layer of TPU fabric can be sequentially laminated and paved on the upper surface of the fabric-based laser-induced graphene, meanwhile, 1 layer of hot melt fabric, 1 layer of TPU film and 1 layer of TPU fabric are sequentially laminated and paved on the lower surface of the fabric-based laser-induced graphene, the fabric of the TPU fabric is arranged on the outer side, and the TPU film is in contact with the TPU film on the inner side. The fabric-based laser-induced graphene electric heating flexible film obtained by the packaging mode has excellent washing and rubbing resistance, good flexibility, good universality and wide application range, and can be used for an electric blanket.

In the invention, the application of different types of flexible packaging materials to the fabric-based laser-induced graphene electric heating flexible film resistor is different, and the fabric substrate is preferably subjected to laser-induced treatment (other conditions such as laser rate and PPI are kept unchanged) at different laser powers so as to ensure that the finally obtained fabric-based laser-induced graphene electric heating flexible film can reach the target heating temperature.

In the invention, the number of pieces of the fabric-based laser-induced graphene in the fabric-based laser-induced graphene electric heating flexible film is preferably more than or equal to 1, namely the number of pieces of the fabric-based laser-induced graphene in the fabric-based laser-induced graphene electric heating flexible film can be one piece (corresponding to one piece of fabric-based laser-induced graphene electric heating flexible film) or multiple pieces (corresponding to multiple pieces of fabric-based laser-induced graphene electric heating flexible film); in the invention, when the number of pieces of the fabric-based laser-induced graphene in the fabric-based laser-induced graphene electric heating flexible film is more than 1, the fabric-based laser-induced graphene is preferably laid on the same horizontal plane.

In the invention, when the number of pieces of the fabric-based laser-induced graphene in the fabric-based laser-induced graphene electric heating flexible film is greater than 1, the connection mode of an equivalent circuit formed by electrodes arranged on each fabric-based laser-induced graphene is preferably series, parallel or series-parallel. According to the invention, different circuit designs and electrode arrangements are used, so that the electrothermal area of the fabric-based laser-induced graphene electrothermal flexible film can be increased under the low-voltage condition, and the electrothermal efficiency is improved. As an embodiment of the invention, the fabric-based laser-induced graphene electrical heating flexible film further comprises a male-female butt connector, and the male-female butt connector is used for performing expandable connection on at least one piece of fabric-based laser-induced graphene in the fabric-based laser-induced graphene electrical heating flexible film and the rest of fabric-based laser-induced graphene. According to the invention, through circuit design and arrangement of the male and female butt connectors, the expandability of the fabric-based laser-induced graphene is increased, namely, the effect of expanding the heating area can be realized through simple connection. In the present invention, the expandable connection is preferably in series at a certain total voltage (up to 220V) limit, the total voltage being the sum of the voltages of the branches.

According to the invention, the fabric-based laser-induced graphene is obtained by performing laser-induced treatment on the fabric substrate, and the digitalized areas with different temperatures can be regulated and controlled on the same piece of fabric-based laser-induced graphene through the digitalized arrangement of each condition in the laser-induced treatment process.

The connection mode of the fabric-based laser-induced graphene and the electrode is not particularly limited, and the fabric-based laser-induced graphene and the electrode can be connected by adopting a mode known to a person skilled in the art according to a preset circuit.

According to the invention, a proper packaging method is preferably selected according to the specific type of the flexible packaging material, specifically, when the flexible packaging material is a laminated PU cloth, a laminated TPU cloth, a PU film, a polyimide film, a hot melt cloth or an epoxy resin prepreg, the preparation raw materials of the flexible packaging material are preferably cut according to actual needs so as to ensure that the fabric-based laser-induced graphene connected with the electrode is fully packaged, then the cut flexible packaging material is laminated and paved on the upper surface and the lower surface of the fabric-based laser-induced graphene connected with the electrode, and the whole flexible packaging material is clamped between the release cloth and then is placed in a hot press for hot press packaging. In the present invention, the hot press is preferably preheated before use, and the preheating temperature is preferably 70 to 120 ℃, more preferably 80 to 110 ℃. In the present invention, the thermocompression package preferably includes a first stage preheating and a second stage thermocompression; the preheating temperature in the first stage is preferably 70-120 ℃, more preferably 80-110 ℃; the pressure of the first stage preheating is preferably 0MPa, namely no additional pressure is needed; the heat preservation time of the first stage preheating is preferably 5-30 min, more preferably 10-20 min; the temperature of the second stage hot pressing is preferably 120-150 ℃, more preferably 125-140 ℃; the pressure of the second stage hot pressing is preferably 1 to 10MPa, more preferably 3 to 9MPa, and even more preferably 5 to 8MPa; the heat and pressure maintaining time of the second stage hot pressing is preferably 5-95 min, more preferably 10-90 min. After the hot-pressing packaging, the obtained material is preferably naturally cooled to 80 ℃ to obtain the fabric-based laser-induced graphene electric heating flexible film.

In the present invention, when the flexible encapsulation material is a polydimethylsiloxane film or a polyurethane elastomer film, it is preferable that the preparation raw materials of the flexible encapsulation material are coated on the upper and lower surfaces of the fabric-based laser-induced graphene to which the electrode is connected, and then cured to achieve the encapsulation. In the present invention, the temperature of the curing is preferably 55 to 65 ℃, more preferably 60 ℃; the time is preferably 2.5 to 3.5 hours, more preferably 3 hours.

Fig. 1 is a flow chart of preparing a fabric-based laser-induced graphene electric heating flexible film according to the invention, specifically, performing laser-induced treatment on a fabric substrate to obtain fabric-based laser-induced graphene, and then connecting electrodes and packaging by adopting a flexible packaging material to obtain the fabric-based laser-induced graphene electric heating flexible film.

In the present invention, when the fabric-based laser-induced graphene electrical heating flexible film includes a male-female docking connector, the preparation method of the fabric-based laser-induced graphene electrical heating flexible film preferably includes:

The invention firstly provides at least two unit modules, and each unit module is obtained by packaging at least one piece of textile-based laser-induced graphene connected with an electrode and preparation raw materials of flexible packaging materials laid or coated on the upper surface and the lower surface of the textile-based laser-induced graphene. In the present invention, the preparation method of the unit module is preferably consistent with the preparation method of the fabric-based laser-induced graphene electrically-heated flexible film in the above technical scheme, and will not be described herein.

After the unit modules are obtained, the method adopts the male and female butt connectors to carry out expandable connection on the unit modules, so as to obtain the fabric-based laser-induced graphene electric heating flexible film. The specific method of use of the male-female mating connector and the specific method of operation of the expandable connection are not particularly limited, and methods well known to those skilled in the art may be employed.

The invention provides an application of the fabric-based laser-induced graphene electric heating flexible film prepared by the technical scheme or the preparation method in preparation of electric heating equipment. In the present invention, the power source employed by the electric heating apparatus preferably includes a low voltage power source or a high voltage power source. The invention divides the power supply into a low-voltage power supply and a high-voltage power supply according to the safety of people, wherein the low-voltage power supply specifically refers to a power supply with voltage of 36V, preferably 5-20V, specifically 5V, 12V or 20V, and the low-voltage power supply can be a common charger, a quick charger and an outdoor power supply respectively; the high-voltage power supply is specifically a power supply with voltage more than or equal to 36V, preferably 220V, and particularly a household 220V alternating current power supply which is converted into a direct current power supply through a converter.

In the present invention, when the power source used by the electric heating device is a low voltage power source, the electric heating device may specifically be an electric heating garment such as: waist support, insole, glove, scarf, knee pad or back integral heating plate; portable heating devices such as: hand warmer, foot warmer or drape blanket; the electric heating cushion can also be a vehicle-mounted electric heating cushion or a vehicle-mounted electric heating headrest; heating or heat preservation equipment in the battery pack of the electric automobile.

In the present invention, when the power source employed by the electric heating apparatus is a high-voltage power source, the electric heating apparatus may specifically be a resident heating apparatus such as: electric heating carpets, electric heating floors or electric heating wall carpets, etc.; industrial heating equipment such as: heating equipment of the tank body and the pipeline or a heat insulation blanket, and a drying box adopted in the industrial processing or production process; agricultural livestock heating equipment such as: heating equipment or heat insulation blanket and vegetable greenhouse heating equipment for breeding seedlings in a greenhouse; engineering deicing and anti-freezing equipment such as: snow melting equipment for highways, bridges, airport runways or satellite antennas.

The technical solutions of the present invention will be clearly and completely described in the following in connection with the embodiments of the present invention. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The polyimide fabric used in the following examples had a gram weight of 75g/cm ² (thickness 0.1 mm); the gram weight of the polyimide paper used in the comparative example was 85g/cm ² (thickness 0.1 mm).

Unless otherwise specified, the packaging methods used in the following examples and comparative examples include three types, respectively:

and A, packaging: adopting single laminated TPU cloth as a flexible packaging material, specifically laying 1 layer of laminated TPU cloth on each of the upper surface and the lower surface of the fabric-based laser-induced graphene, wherein the fabric of the laminated TPU cloth is arranged on the outer side, and the TPU film is contacted with the fabric-based laser-induced graphene on the inner side;

and B, packaging: the method comprises the steps of adopting a laminated TPU cloth, a TPU film and a hot melt cloth to be compounded and used as a flexible packaging material, specifically, sequentially laminating and paving 1 layer of hot melt cloth, 1 layer of TPU film and 1 layer of laminated TPU cloth on the upper surface of fabric-based laser-induced graphene, simultaneously sequentially laminating and paving 1 layer of hot melt cloth, 1 layer of TPU film and 1 layer of laminated TPU cloth on the lower surface of the fabric-based laser-induced graphene, wherein the fabric of the laminated TPU cloth is arranged on the outer side, and the TPU film is in contact with the TPU film on the inner side;

c, packaging: the method is characterized in that the method comprises the steps of adopting laminated TPU cloth, TPU film and hot melt cloth to be compounded and used as a flexible packaging material, specifically, sequentially laminating and paving 2 layers of hot melt cloth, 1 layer of TPU film and 1 layer of laminated TPU cloth on the upper surface of fabric-based laser-induced graphene, simultaneously sequentially laminating and paving 1 layer of hot melt cloth, 1 layer of TPU film and 1 layer of laminated TPU cloth on the lower surface of fabric-based laser-induced graphene, and enabling the fabric of the laminated TPU cloth to be on the outer side, wherein the TPU film is in contact with the TPU film on the inner side.

The grammage of the hot melt cloth in the following examples was 25g/cm ² The thickness of the single-layer laminated PU cloth is 1.5mm, the thickness of the single-layer TPU film is 0.15mm, and the thickness of the single-layer PI film isThe degree was 0.05mm, the thickness of the PDMS film was 2mm, and the thickness of the ECO-Flex film was 2mm; the thickness of the single-layer glass fiber reinforced epoxy resin prepreg was 1mm.

Example 1 preparation of Large area, one piece LIGF electrically heated Flexible film

Preparing a large-area and one-piece LIGF electrically-heated flexible film, which comprises the following steps:

performing laser induction treatment on 1 polyimide fabric to obtain fabric-based laser-induced graphene (LIGF); wherein the area of the polyimide fabric is 46 multiplied by 24cm ² The conditions of the laser-induced treatment include: the vector scanning mode is adopted, the laser power is respectively 5.0W, 5.5W, 6.0W, 6.5W, 7.0W, 7.5W, 8.0W, 8.5W, 9.0W, 9.5W, 10.0W, 12.0W and 18.5W, the laser running speed is 45inch/s, the pixel per inch is 500PPI, and the laser defocusing degree is 2.5mm;

and respectively sticking copper foil conductive adhesive tapes to the two ends of the long side of the LIGF to serve as electrodes, respectively adopting an A packaging mode, a B packaging mode and a C packaging mode to package, taking the A packaging mode as an example, specifically cutting two pieces of matched-size laminated TPU cloth, respectively clamping the laminated TPU cloth on the upper surface and the lower surface of the LIGF on which the electrodes are stuck, enabling the cloth of the laminated TPU cloth to be arranged on the outer side, enabling a TPU film to be in contact with the LIGF on the inner side, then integrally placing the TPU film in a demolding cloth, placing the demolding cloth on a hot press preheated to 110 ℃, treating for 5min (0 MPa) at 110 ℃, then heating the hot press to 140 ℃ and setting the pressure to 8MPa, performing hot press treatment for 10min at the conditions of heat preservation and pressure maintaining, closing the hot press, naturally cooling to 80 ℃, and taking out to obtain a large-area and one-piece LIGF electrically-heated flexible film.

Fig. 2 is an XRD pattern, raman spectrum, laser power-resistance relationship diagram, scanning electron microscope diagram and EDS pattern of the fabric-based laser-induced graphene prepared in example 1. The XRD pattern of LIGF (laser power of 5.0W) in FIG. 2 shows that diffraction peak appears near 2 theta of 23 deg, the peak is widened and strength is weakened, and the diffraction peak is similar to that of graphite, and the product of the polyimide fabric after laser induction treatment is graphene; fig. 2 (b) shows the value of LIGF (laser power)5.0W, 7.5W and 10.0W) respectively, and the results show that in the laser power processing range, the laser-induced products are all graphenes, and the corresponding characteristic peak is 1582cm of the G peak ^-1 D peak 1350cm ^-1 The method comprises the steps of carrying out a first treatment on the surface of the FIG. 2 (c) is a graph showing the relationship between laser power (5.0W, 5.5W, 6.0W, 6.5W, 7.0W, 7.5W, 8.0W, 8.5W, 9.0W, 9.5W, 10.0W) and LIGF resistance when LIGF is prepared, and shows that the sheet resistance of LIGF may be reduced to a minimum of 28.5 Ω/m as the laser power increases ² The method comprises the steps of carrying out a first treatment on the surface of the Fig. 2 (d) and (e) are scanning electron microscope images of LIGF (laser power is 5.0W), wherein (d) shows an interweaving structure of graphene in LIGF, (e) shows an integral fiber plain structure of LIGF and graphene grows upwards on the surface; fig. 2 (f) shows the EDS spectrum of graphene grown up by LIGF, and the result shows that the material grown up by LIGF is mainly carbon.

In the embodiment, a 220V power supply is adopted, the temperature of 85 ℃ is used as a target heating temperature, when the LIGF electric heating flexible film is prepared in an A packaging mode, the laser power required in LIGF preparation is 7.5W, a specific preparation flow chart and an electric heating infrared chart are shown in fig. 3, the result shows that in a larger heating area, the LIGF electric heating flexible film shows a higher heating temperature (85.1 ℃) and good heating uniformity, and the packaged LIGF electric heating flexible film has good heating capacity and is convenient for practical use; when the LIGF electrical heating flexible film is prepared by adopting the B packaging mode, the laser power required by LIGF preparation is 12.0W; when the LIGF electrically-heated flexible film is prepared by adopting the C packaging mode, the laser power required for preparing the LIGF is 18.5W.

The result shows that the resistance of the LIGF electrically-heated flexible film can be regulated and controlled by regulating and controlling the laser power and the packaging mode, so that the regulation and control of the target heating temperature of the LIGF electrically-heated flexible film can be realized; the LIGF electrical heating flexible film prepared in the packaging mode A can be used for an electric heater with a shell and in a regular shape or special shape, such as an electric heating towel rack, the LIGF electrical heating flexible film prepared in the packaging mode B can be used for an electric heating wall tapestry, and the LIGF electrical heating flexible film prepared in the packaging mode C can be used for an electric heating tapestry.

Example 2 preparation of Large usable area, multi-sheet parallel LIGF electrically heated Flexible film

Preparing a large-area and multi-piece parallel LIGF (light-induced thermal film) electrically-heated flexible film, which comprises the following steps:

respectively carrying out laser induction treatment on 10 or 20 polyimide fabrics to obtain fabric-based laser-induced graphene (LIGF); wherein each polyimide fabric has an area of 30×10cm ² The conditions of the laser-induced treatment include: the vector scanning mode is adopted, the laser power is respectively 15W, 18W and 20W, the laser running speed is 35inch/s, the pixel per inch is 500PPI, and the laser defocusing degree is 2.5mm;

respectively sticking copper foil conductive adhesive tapes as electrodes at two ends of a long edge of each LIGF, enabling the electrodes of each LIGF to be connected in parallel, then respectively adopting an A packaging mode, a B packaging mode and a C packaging mode for packaging, taking the C packaging mode as an example, specifically, respectively cutting 2-layer TPU cloth, 2 TPU films and 3 hot melt cloths with matched sizes as packaging materials, sequentially laminating and paving 2 layers of hot melt cloths, 1 layer of TPU film and 1 layer of TPU cloth on the upper surface of the parallel LIGF adhered with the electrodes, simultaneously sequentially laminating and paving 1 layer of hot melt cloth, 1 layer of TPU film and 1 layer of TPU cloth on the lower surface of the parallel LIGF, and enabling the woven cloth of the TPU cloth to be on the outer side, wherein the TPU film is in contact with the TPU film on the inner side; and then the whole body is placed in a demolding cloth and is placed on a hot press preheated to 80 ℃, the hot press is treated for 10min (0 MPa) at 80 ℃, then the hot press is heated to 140 ℃ and the set pressure is 8MPa, the hot press treatment is carried out for 10min under the heat preservation and pressure maintaining conditions, then the hot press is closed, and the hot press is naturally cooled to 80 ℃ and then taken out, so that the large-area and multi-piece parallel LIGF electric heating flexible film is obtained.

Fig. 4 is a flowchart of the preparation of a large-area, multi-sheet parallel LIGF electrically-heated flexible film and a sample real-time chart in example 2, which illustrate that the heating area can be enlarged in a parallel manner to prepare a large-area flexible electrically-heated film.

In the embodiment, a 220V power supply is adopted, 65 ℃ is used as a target heating temperature, and when 20 LIGF electrically-heated flexible films formed by parallel LIGF are prepared by adopting an A packaging mode, the laser power required by LIGF preparation is 15W; when 20 LIGF electrically-heated flexible films formed by parallel LIGF are prepared by adopting a B packaging mode, the laser power required by LIGF preparation is 18W; when 20 LIGF electrically heated flexible films formed by parallel LIGF are prepared by adopting a C packaging mode, the laser power required for preparing the LIGF is 20W.

The large-use-area and multi-sheet parallel LIGF electric heating flexible film prepared by the embodiment expands the heating area in a parallel manner, can be applied to a large-area flexible electric heating film with higher water washing resistance and rubbing resistance, such as an electric blanket (10 polyimide fabrics can be adopted for preparing a single electric blanket and 20 polyimide fabrics can be adopted for preparing a double electric blanket), an electric wall blanket, an electric blanket or a heating fence, and the like, and has the voltage required to be 220V in the use process, so that the household daily use can be met. Specifically, the LIGF is connected in parallel to enlarge the heating area, and soft fabrics such as cotton cloth, cotton fibers and the like are generally adopted to wrap the LIGF electric heating flexible film in actual use, so that the LIGF electric heating flexible film has heat conduction, heat diffusion and heat accumulation in the actual use process and does not need to carry out large-area integral heating, and therefore, the LIGF electric heating flexible film is connected in parallel to obtain a larger heating area.

The large-use-area and multi-piece parallel LIGF electric heating flexible film prepared in the C packaging mode in the embodiment is subjected to water washing and rubbing resistance test, specifically, a washing machine with the model of OxQB 55-A1678 is used for machine washing, wherein 1 machine washing is specifically in a standard mode, the washing machine is taken out for 40min, and then naturally dried for 24h, and 20 machine washing is performed. The results show that after 20 times of machine washing, the heating temperature change rate of the large-use-area multi-sheet parallel LIGF electrically-heated flexible film prepared by adopting the C packaging mode in the embodiment is less than 5%, and no local hot spots exist, which indicates that the machine washing-resistant rubbing function is better, and the heating performance is still excellent after 20 times of machine washing.

Example 3 preparation of Multi-sheet parallel Low-Voltage LIGF electrically heated Flexible film

Preparing a plurality of parallel low-voltage LIGF electrically-heated flexible films, which comprises the following steps:

(1) Carrying out laser induction treatment on 3 polyimide fabrics to obtain fabric-based laser-induced graphene (LIGF), wherein the fabric-based laser-induced graphene is marked as 1#LIGF; wherein each polyimide fabric has an area of 15×10cm ² The conditions of the laser-induced treatment include: the vector scanning mode is adopted, the laser power is respectively 4.5W, 5.5W and 6.25W, the laser running speed is 50inch/s, the pixel per inch is 500PPI, and the laser defocusing degree is 2.5mm;

(2) Carrying out laser induction treatment on 4 polyimide fabrics to obtain fabric-based laser-induced graphene (LIGF), wherein the fabric-based laser-induced graphene is marked as 2#LIGF; wherein each polyimide fabric has an area of 20×1.5cm ² The conditions of the laser-induced treatment include: the vector scanning mode is adopted, the laser power is respectively 3.5W, 4W and 5W, the laser running speed is 25inch/s, the pixel per inch is 500PPI, and the laser defocusing degree is 2.5mm;

(3) Carrying out laser induction treatment on 3 polyimide fabrics to obtain fabric-based laser-induced graphene (LIGF), wherein the fabric-based laser-induced graphene is marked as 3#LIGF; wherein each polyimide fabric has an area of 16×2cm ² The conditions of the laser-induced treatment include: the vector scanning mode is adopted, the laser power is respectively 4W, 5W and 6W, the laser running speed is 40inch/s, the pixel per inch is 500PPI, and the laser defocusing degree is 2.5mm;

(4) Carrying out laser induction treatment on 6 polyimide fabrics with different areas respectively to obtain fabric-based laser-induced graphene (LIGF), and marking the fabric-based laser-induced graphene as 4#LIGF; wherein each polyimide fabric has an area of 1X 1cm ² 、3×3cm ² 、5×5cm ² 、10×10cm ² 、15×15cm ² 、20×20cm ² The conditions of the laser-induced treatment include: the vector scanning mode is adopted, the laser power is 5W respectively, the laser running speed is 25inch/s, each inch of pixels is 500PPI, and the laser defocusing degree is 2.5mm;

Respectively sticking copper foil conductive tapes at two ends of the LIGF (namely 1#LIGF, 2#LIGF, 3#LIGF and 4#LIGF) as electrodes (for reasonably distributing current and improving the electric energy utilization rate, the slender LIGF needs to arrange the electrodes on the long side, the LIGF with the length-width ratio close to 1:1 needs to arrange the electrodes on the short side), connecting the electrodes of each LIGF in parallel among the 1#LIGF, 2#LIGF and 3#LIGF (each LIGF in 4#LIGF is not connected in parallel, and the single LIGF is tested after being subjected to subsequent encapsulation), then respectively adopting an A encapsulation mode, a B encapsulation mode and a C encapsulation mode for encapsulation, taking the C encapsulation mode as an example, specifically, respectively cutting 2-layer TPU-bonded fabrics, 2 TPU films and 3 heat-fusible fabrics with matched sizes as encapsulation materials, sequentially laying 2 heat-fusible fabrics, 1 TPU film and 1 TPU fabric on the upper surface of the parallel LIGF stuck with the electrodes, sequentially laying 1 TPU film and 1 TPU fabric on the lower surface, and sequentially laying 1 TPU film and bonding the TPU film on the two heat-layer TPU fabric layers, and bonding the TPU film and the TPU film is contacted with the TPU film; and then the whole body is placed in a demolding cloth and is placed on a hot press preheated to 80 ℃, the hot press is treated for 10min (0 MPa) at 80 ℃, then the hot press is heated to 140 ℃ and the set pressure is 8MPa, the hot press treatment is carried out for 10min under the heat preservation and pressure maintaining conditions, then the hot press is closed, and the hot press is naturally cooled to 80 ℃ and then taken out, so that a plurality of pieces of parallel low-voltage LIGF electrically-heated flexible films are obtained.

Fig. 5 is a circuit design diagram and an electrical heating infrared diagram (a) of a plurality of parallel low-voltage LIGF electrically heated flexible films and a diagram (b) of the influence of LIGF size on electrothermal temperature in example 3, wherein the first row of (a) in fig. 5 corresponds to 1#ligf (in C package), the second row corresponds to 2#ligf (in C package), the third row corresponds to 3#ligf (in C package), and the (b) in fig. 5 corresponds to 4#ligf (in C package). Specifically, in this embodiment, a 12V power supply is used, and a target heating temperature is 60 ℃, so when a plurality of parallel low-voltage LIGF electrically heated flexible films are prepared by adopting an a-package mode, the laser power required for preparing 1#ligf is 4.5W; when a B packaging mode is adopted to prepare a plurality of parallel low-voltage LIGF electrically-heated flexible films, the laser power required for preparing the 1#LIGF is 5.5W; when a C packaging mode is adopted to prepare a plurality of parallel low-voltage LIGF electrically-heated flexible films, the laser power required for preparing the 1#LIGF is 6.25W. Adopting a 12V power supply and taking 120 ℃ as a target heating temperature, and when a plurality of parallel low-voltage LIGF electrically-heated flexible films are prepared in an A packaging mode, the laser power required for preparing the 2#LIGF is 3.5W; when a B packaging mode is adopted to prepare a plurality of parallel low-voltage LIGF electrically-heated flexible films, the laser power required for preparing the 2#LIGF is 4W; when a C packaging mode is adopted to prepare a plurality of parallel low-voltage LIGF electrically-heated flexible films, the laser power required for preparing the 2#LIGF is 5W. Adopting a 12V power supply, taking 60 ℃ as a target heating temperature, and when preparing a plurality of parallel low-voltage LIGF electrically-heated flexible films in an A packaging mode, preparing 3#LIGF, wherein the required laser power is 4W; when a B packaging mode is adopted to prepare a plurality of parallel low-voltage LIGF electrically-heated flexible films, the laser power required for preparing the 3#LIGF is 5W; when a C packaging mode is adopted to prepare a plurality of parallel low-voltage LIGF electrically-heated flexible films, the laser power required for preparing the 3#LIGF is 6W. As can be illustrated in fig. 5 (a), the resistance of the monolithic LIGF can be precisely controlled by controlling the laser power when the polyimide fabric is subjected to laser induction treatment, and the purpose of obtaining high electrothermal temperature under the condition of low input power is achieved through circuit design (such as parallel connection). As can be seen from fig. 5 (b), the different ratios of the area to perimeter of the LIGF affect the thermal diffusion and thus the electrothermal temperature.

The multi-piece parallel low-voltage LIGF electric heating flexible film prepared by the embodiment enlarges the heating area in a parallel manner, wherein a C packaging manner is adopted to prepare a large-area flexible electric heating film which needs higher washing resistance and rubbing resistance and is powered by a mobile power supply, such as a hand warmer, a foot pad, a heating scarf, a heating cushion, a heating pillow, a heating eyeshade, a heating pillow, a heating knee pad and the like, so that the problem that a heating scene is limited due to the fact that a higher voltage (220V) is needed is avoided, and the mobile outdoor use requirements of low-voltage power supply, high use temperature can be met.

Example 4 preparation of Multi-sheet parallel Low-voltage LIGF electrically heated Flexible film with Male and female Butt connectors

Preparing a plurality of pieces of parallel low-voltage LIGF electrically-heated flexible films containing male and female butt connectors, which comprises the following steps:

the multiple parallel low-voltage LIGF electrically heated flexible films (corresponding to 1#ligf or 2#ligf in example 3) in example 3 were connected in an expandable manner using male and female docking connectors to obtain multiple parallel low-voltage LIGF electrically heated flexible films containing male and female docking connectors.

Fig. 6 is a schematic diagram of a low-voltage LIGF electrically heated flexible film in embodiment 4, in which the heating area and the expansibility are improved by connecting in parallel and adding a male-female butt connector, and in this embodiment, a plurality of parallel low-voltage LIGF electrically heated flexible films in embodiment 3 are used as heating units, and the male-female butt connector is added on the premise of meeting the power supply requirement, so that the problem that the plurality of parallel low-voltage LIGF electrically heated flexible films in embodiment 3 cannot be expanded due to the limited size caused by the integrated hot-pressing process in the use process can be effectively solved.

The heating area of the low-voltage LIGF electric heating flexible film is enlarged in a parallel connection mode, and the heating area is connected in an extensible mode by using the male-female butt joint connector, so that the purpose of extending and using is achieved, the electric heating flexible film can be applied to a large-area electric heating flexible film with high water-resistant and rubbing-resistant performances, meanwhile, the requirement of extending the electric heating film can be met, and the electric heating flexible film can be used as a heating picnic pad or a moistureproof pad in a more extreme environment such as the open air (in a plateau) under the condition of sufficient power supply, and also can be used as a multi-series-parallel combined heat tracing belt for heating a pipeline.

Example 5 preparation of Multi-mode hybrid Circuit Voltage LIGF electrically heated Flexible thin film

The method for preparing the low-voltage LIGF electric heating flexible film of the multi-module series-parallel circuit comprises the following steps:

performing laser induction treatment on 32 polyimide fabrics to obtain fabric-based laser-induced graphene (LIGF); wherein each polyimide fabric has an area of 1X 1cm ² (referring to an actual heating area of 1X 1 cm) ² The electrodes need to be arranged in excess), the conditions of the laser-induced treatment include: the vector scanning mode is adopted, the laser power is 5W, 5.5W and 6W respectively, the laser running speed is 25inch/s, the pixel per inch is 500PPI, and the laser defocusing degree is 2.5mm;

Respectively sticking copper foil conductive adhesive tapes as electrodes at two ends of a long edge of each LIGF, carrying out series-parallel arrangement on each LIGF, then respectively adopting an A packaging mode, a B packaging mode and a C packaging mode for packaging, taking the C packaging mode as an example, specifically respectively cutting 2-post TPU cloth, 2 TPU films and 3 hot melt cloths with matched sizes as packaging materials, sequentially laminating 2 layers of hot melt cloths, 1 layer of TPU film and 1 layer of TPU cloth on the upper surface of the parallel LIGF adhered with the electrodes, simultaneously sequentially laminating 1 layer of hot melt cloth, 1 layer of TPU film and 1 layer of TPU cloth on the lower surface of the TPU cloth, and enabling the woven cloth of the TPU cloth to be outside, wherein the TPU film is in contact with the TPU film on the inner side; and then the whole body is placed in a demolding cloth and is placed on a hot press preheated to 80 ℃, the hot press is treated for 10min (0 MPa) at 80 ℃, then the hot press is heated to 140 ℃ and the set pressure is 8MPa, the hot press treatment is carried out for 10min under the heat preservation and pressure maintaining conditions, then the hot press is closed, and the hot press is naturally cooled to 80 ℃ and then taken out, so that the multi-module series-parallel circuit low-voltage LIGF electric heating flexible film is obtained.

Fig. 7 is a low-voltage LIGF electrical heating flexible film physical diagram and an electrical heating infrared diagram (C package mode) of the multi-module series-parallel circuit in example 5. When LIGF area is 1X 1cm ² The resistance is the smallest and the electric heating efficiency is the highest, thus the electric heating efficiency is the same as that of the electric heating device with the temperature of 1X 1cm ² LIGF carries out series-parallel array arrangement to satisfy the demand that increases the heat radiation area. Specifically, in this embodiment, a 20V power supply is used, and 90 ℃ is used as a target heating temperature, and when a multi-module series-parallel circuit low-voltage LIGF electrically heated flexible film is prepared by adopting an a packaging mode, the laser power required for preparing LIGF is 5W; when a B packaging mode is adopted to prepare the low-voltage LIGF electric heating flexible film of the multi-module series-parallel circuit, the laser power required by LIGF preparation is 5.5W; when the C packaging mode is adopted to prepare the low-voltage LIGF electric heating flexible film of the multi-module series-parallel circuit, the laser power required by LIGF preparation is 6W. Therefore, compared with simple parallel connection, the multi-module series-parallel connection circuit further improves the utilization of electric energy, and though the punctiform heating area is smaller, the multi-module series-parallel connection circuit still can achieve higher heating temperature in a shorter time through heat conduction and heat accumulation, and is large in heat radiation area, even in heat distribution and more suitable for heating a human body.

The heating area of the low-voltage LIGF electric heating flexible film is enlarged through a multi-module series-parallel mode, wherein a C packaging mode is adopted to prepare the large-area electric heating flexible film which is applied to the back of a jacket, a carpet and the like and needs higher washing resistance and rubbing resistance, and is powered by a mobile power supply and supplied with heat in a point mode.

Example 6 control of heating temperature and heating area Using laser in sheet-type LIGF electrically heated Flexible film

Performing laser induction treatment on 1 polyimide fabric to obtain fabric-based laser-induced graphene (LIGF); wherein the area of the polyimide fabric is 15 multiplied by 5cm ² The conditions of the laser-induced treatment include: the vector scanning mode is adopted, the laser power is respectively 5W, 6.5W and 8W (namely, the laser powers adopted in different areas of the same polyimide fabric are different), the laser running speed is 10inch/s, the pixel per inch is 500PPI, and the laser defocusing degree is 2.5mm; then, a one-piece LIGF electrically heated flexible film was prepared by the procedure of example 5, C encapsulation.

FIG. 8 is an infrared chart of electric heating of a sheet-type LIGF electric heating flexible film with adjustable heating temperature and heating area in example 6, wherein A in FIG. 8 is an electric heating flexible film formed by connecting 3 sheet resistors (laser power is 5W, 6.5W and 8W respectively) in the same sheet LIGF in parallel, B is an electric heating flexible film formed by connecting 3 sheet resistors (laser power is 5W, 6.5W and 8W respectively) in the same sheet LIGF in series, C is 2 sheet resistors (laser power is 5W and left sheet resistor area is 1 cm) in the same sheet LIGF ² The resistance area of the right side piece is 4cm ² ) The electrically heated flexible films formed in series were each provided with 2 sheet resistors (laser power was 5W and left sheet resistance area was 1cm in the same sheet LIGF ² The resistance area of the right side piece is 9cm ² ) Electrically heated flexible films formed in series; wherein, voltages of 20V are adopted for A to D. As can be seen from FIG. 8, by adjusting the laser processing parameters (such as laser power) of each region by laser selective processing, the high-temperature or low-temperature heating of the region at a specific position can be realized in one step, and simultaneously the number and the area size of the high-temperature or low-temperature regions can be synchronously adjusted by digital laser processing。

In the embodiment, by utilizing CAD patterning and precise regulation and control of laser-induced processing conditions, the integrated design and manufacture of the LIGF electrically-heated flexible film can be realized, and the problem that a plurality of LIGF electrodes are consumed due to electrode connection is avoided.

EXAMPLE 7LIGF and other composite encapsulation

A flexible film electrically heated by LIGF was prepared as in example 1, except that the encapsulating materials used in this example were:

(1) A single PI film is adopted as a packaging material, namely, the laminated TPU cloth in the packaging mode A in the embodiment 1 is replaced by the PI film;

(2) The single glass fiber reinforced epoxy resin prepreg is adopted, namely the attached TPU fabric in the A packaging mode in the embodiment 1 is replaced by the glass fiber reinforced epoxy resin prepreg, and the conditions of hot-pressing packaging are as follows: placing on a hot press preheated to 80 ℃, treating for 30min (0 MPa) at 80 ℃, heating the hot press to 125 ℃ and setting the pressure to 3MPa, performing hot press treatment for 90min under the conditions of heat preservation and pressure maintaining, closing the hot press, naturally cooling to 80 ℃, and taking out;

(3) Adopting a single PDMS film as a packaging material, specifically spin-coating the preparation raw materials of the PDMS film on the upper surface and the lower surface of the fabric-based laser-induced graphene connected with the electrode, and then curing for 3 hours at 60 ℃;

(4) A single ECO-Flex film is adopted as a packaging material, specifically, the preparation raw materials of the ECO-Flex film are spin-coated on the upper surface and the lower surface of the fabric-based laser-induced graphene connected with the electrode, and then the ECO-Flex film is cured for 3 hours at the temperature of 60 ℃.

Fig. 13 is a physical diagram of a LIGF electrically heated flexible film prepared from different packaging materials, wherein (a) is a polyimide film package, (b) is an epoxy resin prepreg package, (c) is a PDMS package, and (d) is an ECO-Flex package.

FIG. 9 is a schematic diagram of bending and heating the LIGF electrically-heated flexible film prepared in example 7, wherein the packaging materials used from left to right are polyimide film, epoxy resin prepreg, PDMS and ECO-Flex in sequence; the results show that the LIGF electrically heated flexible film still maintains uniform heating performance under the condition of large bending. The characteristics of different packaging materials determine the use property and the scene of the LIGF electrical heating flexible film, and the LIGF electrical heating flexible film prepared by the invention can keep the uniform heating performance under bending with large bending and multiple dimensions, and is suitable for the flexible heating field.

Example 8

Performing laser induction treatment on 1 polyimide fabric to obtain fabric-based laser-induced graphene (LIGF); wherein each polyimide fabric has an area of 5×5cm ² The conditions of the laser-induced treatment include: the vector scanning mode is adopted, the laser power is 6W, the laser running speed is 25inch/s, the pixel per inch is 500PPI, and the laser defocusing degree is 2.5mm;

respectively sticking copper foil conductive tapes as electrodes at two ends of a long edge of the LIGF, respectively cutting two TPU films and hot melt cloths which are matched in size as packaging materials, respectively laminating and clamping the packaging materials on the upper surface and the lower surface of the LIGF with the electrodes, wherein the packaging materials are the TPU films and the hot melt cloths in sequence from outside to inside; and then the whole body is placed in a demolding cloth and is placed on a hot press preheated to 80 ℃, the hot press is treated for 10min at 80 ℃, then the hot press is heated to 140 ℃ and the set pressure is 8MPa, the hot press treatment is carried out for 10min under the heat preservation and pressure maintaining conditions, then the hot press is closed, and the LIGF electric heating flexible film is obtained after the hot press is naturally cooled to 80 ℃.

The LIGF electrically heated flexible film prepared in this example was applied with different voltages (5.00V, 10.0V, 20.0V, 30.0V, 50.0V, 100V, respectively) and the heating and cooling times and the maximum temperatures at the corresponding voltages were measured. FIG. 10 is a graph showing the electrical heating performance test of the LIGF electrical heating flexible film prepared in example 8. As can be seen from FIG. 10, the LIGF electrical heating flexible film provided by the invention has excellent electrical heating performance, calculated by taking the time required for 90% of the temperature change of the temperature rise as the temperature rise time, the shortest temperature rise time is about 3.2s, and the average temperature rise rate is 152.4 ℃/s; the shortest cooling time is about 8s, and the average cooling rate is 61 ℃/s.

Comparative example 1

The procedure of example 8 was followed except that the polyimide fabric was replaced with polyimide paper, and finally a LIGP electrically heated flexible film was obtained.

FIG. 11 is a physical image and an electrical heating infrared image of the LIGP electrically heated flexible film prepared in comparative example 1 and the LIGF electrically heated flexible film prepared in example 8; specifically, in fig. 11 (a), the upper left is a physical diagram of the newly prepared LIGP electrically heated flexible film, the upper right is a physical diagram of the newly prepared LIGF electrically heated flexible film, the lower left is an electrically heated infrared diagram of the newly prepared LIGP electrically heated flexible film, and the lower right is an electrically heated infrared diagram of the newly prepared LIGF electrically heated flexible film; the results show that the LIGP electric heating flexible film prepared by taking the laser-induced graphene paper (LIGP) obtained by laser-induced treatment of polyimide paper as a matrix is uneven and cannot be freely spread out in a plane, and the internal structure is compact, so that packaging materials such as TPU films, hot melt fabrics and the like are not beneficial to flowing in the plane in the hot pressing process, the interior of the prepared LIGP electric heating flexible film is uneven, and the heating uniformity degree of the LIGP electric heating flexible film is reduced. The newly prepared LIGP electric heating flexible film and the newly prepared LIGF electric heating flexible film are manually rubbed for 10min under the same conditions, wherein a physical image and an electric heating infrared image are shown in (b) of fig. 11, specifically, the upper left part of (b) of fig. 11 is a physical image of the rubbed LIGP electric heating flexible film, the upper right part is a physical image of the rubbed LIGF electric heating flexible film, the lower left part is an electric heating infrared image of the rubbed LIGP electric heating flexible film, and the lower right part is an electric heating infrared image of the rubbed LIGF electric heating flexible film; the results show that after the LIGP electric heating flexible film prepared by using LIGP as a matrix is subjected to kneading experiments, the heating uniformity is greatly damaged, local overheating or local low temperature occurs, the LIGP electric heating flexible film prepared by using LIGF as a matrix can be naturally unfolded after being kneaded under the same conditions, the electric heating performance of the LIGP electric heating flexible film keeps better stability, and the electric heating temperature change rate of the LIGP electric heating flexible film before being kneaded is less than 2%.

Example 9

Performing laser induction treatment on 1 polyimide fabric to obtain fabric-based laser-induced graphene (LIGF); wherein,the area of the polyimide fabric is 20 multiplied by 20cm ² The conditions of the laser-induced treatment include: the vector scanning mode is adopted, the laser power is 5W, the laser running speed is 10inch/s, the pixel per inch is 500PPI, and the laser defocusing degree is 2.5mm; then, a one-piece LIGF electrically heated flexible film was prepared by the procedure of example 5, C encapsulation.

The performance test of the one-piece LIGF electrically heated flexible film prepared in this example was performed as follows: and (3) using a program to set a control power supply to supply power, attaching a thermocouple to the central point of a sheet LIGF electric heating flexible film, connecting an ammeter to detect the temperature, and drawing the acquired temperature data into a graph.

Fig. 12 is a graph showing the results of testing the cycle performance of the one-piece flexible thin film with LIGF electrical heating prepared in example 9, wherein the cycle number is 5000, the total time of each cycle is 10s, specifically, the power is turned on for 5s, and then the power is turned off for 5s, and the results show that the one-piece flexible thin film with LIGF electrical heating prepared in example 9 still shows good heating stability after 5000 times of heating and cooling.

From the above embodiments, the present invention has at least the following advantages:

1. the processing method comprises the following steps:

(1) The preparation method adopts the laser-induced combined hot-pressing packaging technology to realize the preparation of the fabric-based laser-induced graphene (LIGF), has the advantages of simplicity, low cost, high processing efficiency, no need of special atmosphere, capability of directly converting the fabric substrate into LIGF in an air environment, mild preparation environment, completion of the whole processing process in the next step of computer-aided design, no need of participation of a catalyst, no generation of toxic and harmful gas and environmental friendliness; the processing process can be expanded to realize volume-to-volume mass production, so that the rapid preparation of large-size products is realized; in addition, the electrothermal performance of LIGF can be regulated and controlled integrally or regionally through laser processing parameters, and customized design can be realized according to special requirements of different clients on samples in different environments. The traditional graphene fabric preparation process comprises an impregnation method, a spraying method, an electrophoretic deposition method, a blend spinning method, a chemical vapor deposition method and the like, wherein the impregnation method (1) is used for preparing the graphene composite textileMost often, and also the simplest, the textile is simply placed directly in a uniform dispersion of graphene or graphene oxide. Since graphene has no charge on the surface, it is easy to agglomerate and precipitate in water, and it is often necessary to use a dispersant such as N-methylpyrrolidone (NMP) and a surfactant such as diazonium salt, and an alkali reducing agent [ K (1S-crown-S) ₂ ]Na, etc. However, the removal of these surfactants and dispersants often involves high temperature or harsh chemical treatments which can otherwise affect the performance of the fabric, further increasing the cost of production; (2) the spraying method is to spray graphene or graphene and other polymer uniform dispersion liquid onto the fabric by using spraying equipment, and prepare the graphene composite fabric through reduction. The equipment for preparing the graphene-based fabric by the spraying method is simple to operate, but needs to be sprayed for many times to ensure the content of graphene, and the problem that the graphene is unevenly dispersed in the fabric exists; (3) the electrophoresis deposition method is one of important surface treatment technologies, and its working principle is to deposit charged colloid particles on electrodes under the action of electric field force, so that the method is widely applied in textile coating processing. Cathodic electrophoretic deposition corresponds to the deposition of positively charged particles on the negative electrode (cathode), and anodic electrophoretic deposition corresponds to the deposition of negatively charged particles on the positive electrode (anode). The regulation and control of the two deposition modes can be realized through modification of the surface charge of the particles. Graphene is generally rendered electrically neutral, and can be modified with magnesium nitrate to positively migrate to the cathode for deposition, or negatively charged graphene oxide for anodic deposition. However, in general, the method needs to perform certain pretreatment on the fabric, so that the fabric has certain charges, and the process cost is increased; (4) the blending spinning method is to directly mix the graphene nano particles with polymer melt or solution, and then spin the graphene nano particles into graphene blending fibers through wet spinning, electrostatic spinning or melt spinning. However, adding graphene nanoparticles to a polymer tends to make the raw material viscous, making it difficult to disperse, resulting in uneven distribution of the graphene nanoparticles. The method does not realize the full coverage of the graphene on the fiber, can cause discontinuous conductive paths, has poor conductive performance and can also generate stones The weak binding force of the graphene nano-ions and the polymer causes potential problems such as brittle fracture and the like; (5) the chemical vapor deposition method can enable the surface of the fabric to grow into a graphene film, and can also directly prepare the pure graphene fabric. At present, when a chemical vapor deposition method is used for preparing a pure graphene fabric, a copper mesh is commonly used as a substrate, graphene is deposited on the substrate, and a chemical reagent is used for removing the copper mesh. However, this method has the disadvantages of high equipment and environment requirements, high price and low raw material utilization rate. In summary, the existing preparation method of the graphene fabric has the problems of long operation time, complex process, high pollution and the like, and the method for preparing the graphene fabric by using the laser-induced graphene can effectively solve the problems.

(2) According to the invention, the digital regulation and control of the structural size of the fabric-based laser-induced graphene can be easily realized by adjusting the technological parameters of laser-induced treatment. Specifically, the invention can realize the customization of LIGF size patterns through an open laser printing platform and patterning design software; the design of the pattern and the size customization of the fabric-based laser-induced graphene is realized through the shape design customized by computer software.

(2) The invention can realize LIGF performance regulation. Specifically, the resistance of LIGF is adjustable by adjusting parameters of laser induction treatment; by selecting different flexible packaging materials, the resistance of LIGF is adjusted and controlled cooperatively by the properties of rubbing resistance, washing resistance, high temperature resistance and the like. Both the two modes have influence on the resistance of LIGF, so that the electric heating characteristic of LIGF is regulated and controlled; the distribution of current and voltage is completed through the design of the electrode circuit of the LIGF, and the accurate regulation and control of the electric heating area and the electric heating temperature are achieved through the serial-parallel connection design of the circuit. In the process of circuit optimization, the heating effect of low-voltage portable equipment serving as a power supply can be finally achieved.

2. Product layer:

(1) The size, shape and electric heating temperature of the product can be customized. Specifically, the LIGF dimension can be expanded, so that the LIGF with large or small size can be obtained; meanwhile, the regulation and control of different shapes in the LIGF plane can be realized, and the LIGF of the customized heating pattern can be obtained.

(2) The product has multifunction and controllable performance. Specifically, the resistance of the product can be regulated and controlled; the heating capacity of accurate point location heating and large effective use area of the product can be improved, and the product has accuracy and universality; the effect of low-voltage power supply of the portable equipment (such as a charger) to the heating device can be finally achieved based on the design of the circuit, so that the portable equipment becomes a preferable scheme of the low-voltage portable heating equipment; based on different temperature resistance degrees of different packaging materials, the highest heating temperature (50-300 ℃) of the product can be influenced; the area of the fabric-based laser-induced graphene electric heating flexible film can be expanded, and convenience and portability in practical application are improved.

(3) The product is resistant to various severe environmental interferences. The invention adopts the packaging materials such as PU/TPU film and the like to have small influence on LIGF heating temperature and heating rate, if the sheet resistance is about 10-30 omega/sq, the heating rate is within-5 ℃/s, but the invention can effectively improve the rubbing resistance, the water washing resistance and the chemical reagent soaking performance of LIGF, and can maintain stable electric heating performance.

(4) Product performance advantages:

the heat stability is good: LIGF heats evenly, has good mechanical stability, can bear various complex stretching, bending and compression deformations, can still maintain heating evenly, and heats stably; meanwhile, the electrothermal film is durable and long in service life, and can still maintain excellent heating characteristics even after 5000 heating cycles.

The electrothermal conversion efficiency is high: LIGF thermal conversion efficiency up to 371 ℃ cm ² The maximum stable temperature of the air conditioner can reach 600 ℃ under the air environment; the heating efficiency is high, and the highest temperature under specific input power can be reached within 8 seconds; can be heated at low voltage and is stably and uniformly heated to more than 80 ℃ under the energy supply of a 5V 2A universal charger.

Region temperature/pattern customization: the LIGF can customize different patterns or structures according to the requirements of clients, meets the requirements of heating scenes with different dimensions, and can be designed into heating patterns with arbitrary plane shapes; a heating coil or the like may be wound. More importantly, the laser processing characteristics can be utilized to regulate and control the whole or regional temperature in a large range, so that the regional heating temperature differentiation is realized, or the use requirement of a gradient heating scene is met.

Complex circuit design: LIGF can customize different serial/parallel/series-parallel connection heating plate connection modes according to customer demands, satisfies the heating application scene of integration, multidimension, for example can design into many parallel circuits, satisfies the human heating effect of large tracts of land, low voltage.

The temperature rise and reduction rate is fast: the shortest heating time of the fabric-based laser-induced graphene electric heating flexible film is about 3.2s, and the average heating rate is 152.4 ℃/s; the shortest cooling time is 8s, and the average cooling rate is 61 ℃/s. The fabric-based laser-induced graphene electric heating flexible film overcomes the problem of low temperature rise and fall rate of the traditional carbon-based electric heating film, is beneficial to widening the application range of the film, can be applied to precise medical equipment (such as an eye therapeutic instrument) needing heating, and can reduce unnecessary over-temperature damage by rapid temperature reduction.

3. Application level:

(1) LIGF can be constructed as a distinct shaped, self-contained device embedded or attached in other materials to precisely heat the desired location at low voltage. The invention finally achieves the heating effect with low voltage and large area by regulating and controlling the shape and the area of the graphene and the circuit design through laser, and has great advantages in application.

(2) The packaged LIGF has the performances of water washing resistance, rubbing resistance, chemical corrosion resistance, high temperature resistance and the like, and can greatly prolong the service life in practical application. The LIGF packaging structure can greatly improve the structural strength after being packaged, and can meet the requirements of daily life application scenes such as water resistance, rubbing resistance and the like.

(3) The LIGF has wider application field than the traditional electrothermal film on the premise of keeping good mechanical property, the regional regulation and control advantages can be used for assembling the thermal driver with controllable posture, the excellent flexibility can be used for customized production of the wearable thermal therapeutic device, and different target groups can be satisfied; in addition, LIGF-based fabric-based lasersThe photoinduction graphene electric heating flexible film has certain advantages in price, and the fabric-based laser-induced graphene electric heating flexible film per square meter is cheaper than other manufacturers by more than 15 percent (about 85 yuan/m) ² ) Plays an important role in the technical innovation, application and popularization of the efficient preparation of the carbon-based electrothermal film in the future.

The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.

Claims

1. The fabric-based laser-induced graphene electric heating flexible film is characterized by comprising fabric-based laser-induced graphene, electrodes and a flexible packaging material, wherein the electrodes are arranged at two ends of the fabric-based laser-induced graphene, and the flexible packaging material is packaged on the upper surface and the lower surface of the fabric-based laser-induced graphene.

2. The fabric-based laser-induced graphene electrical heating flexible film according to claim 1, wherein the number of pieces of fabric-based laser-induced graphene in the fabric-based laser-induced graphene electrical heating flexible film is equal to or greater than 1, and when the number of pieces of fabric-based laser-induced graphene in the fabric-based laser-induced graphene electrical heating flexible film is greater than 1, each fabric-based laser-induced graphene is laid on the same horizontal plane.

3. The fabric-based laser-induced graphene electric heating flexible film according to claim 2, wherein when the number of pieces of the fabric-based laser-induced graphene in the fabric-based laser-induced graphene electric heating flexible film is greater than 1, the connection mode of an equivalent circuit formed by electrodes arranged on each fabric-based laser-induced graphene is series, parallel or series-parallel.

4. The fabric-based laser-induced graphene electrically heated flexible film of claim 3, further comprising a male-female docking connector for expandable connection of at least one piece of fabric-based laser-induced graphene in the fabric-based laser-induced graphene electrically heated flexible film with the remaining fabric-based laser-induced graphene.

5. The fabric-based laser-induced graphene electrically heated flexible film according to any one of claims 1 to 4, wherein the fabric-based laser-induced graphene is obtained by subjecting a fabric substrate to a laser-induced treatment; the fabric substrate comprises one or more of polyimide fabric, silk fabric, aramid fabric and cotton cloth.

6. The fabric-based laser-induced graphene electrically heated flexible film according to any one of claims 1 to 4, wherein the flexible encapsulation material comprises one or more of a PU cloth, a TPU cloth, a PU film, a polyimide film, a hot melt cloth, a polydimethylsiloxane film, a polyurethane elastomer film, and an epoxy prepreg.

7. The method for preparing the fabric-based laser-induced graphene electric heating flexible film according to any one of claims 1 to 6, which is characterized by comprising the following steps:

8. The method of preparing a fabric-based laser-induced graphene electrically heated flexible film according to claim 7, wherein when the fabric-based laser-induced graphene electrically heated flexible film includes a male-female docking connector therein, the method of preparing a fabric-based laser-induced graphene electrically heated flexible film comprises:

9. The use of the fabric-based laser-induced graphene electrically heated flexible film according to any one of claims 1 to 6 or the fabric-based laser-induced graphene electrically heated flexible film prepared by the preparation method according to any one of claims 7 to 8 in the preparation of an electric heating device.

10. The use according to claim 9, wherein the power source employed by the electric heating device comprises a low voltage power source or a high voltage power source.