CN115340087A - Graphene lithium ion battery cathode composite material and preparation method thereof - Google Patents

Graphene lithium ion battery cathode composite material and preparation method thereof Download PDF

Info

Publication number
CN115340087A
CN115340087A CN202211008841.8A CN202211008841A CN115340087A CN 115340087 A CN115340087 A CN 115340087A CN 202211008841 A CN202211008841 A CN 202211008841A CN 115340087 A CN115340087 A CN 115340087A
Authority
CN
China
Prior art keywords
graphene
lithium ion
ion battery
composite material
negative electrode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202211008841.8A
Other languages
Chinese (zh)
Inventor
闫宏震
林峰
王志明
刘来琛
汪乔臻
秦成真
钟宏
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
University of Electronic Science and Technology of China
Yunnan University YNU
Original Assignee
University of Electronic Science and Technology of China
Yunnan University YNU
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by University of Electronic Science and Technology of China, Yunnan University YNU filed Critical University of Electronic Science and Technology of China
Priority to CN202211008841.8A priority Critical patent/CN115340087A/en
Publication of CN115340087A publication Critical patent/CN115340087A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/182—Graphene
    • C01B32/194—After-treatment
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/027—Negative electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The invention provides a graphene lithium ion battery cathode composite material and a preparation method thereof, wherein the material comprises the following components: the graphene nano sheet comprises two-dimensional graphene nano sheets, a polymer matrix material, a dispersing agent and a conductive additive; the mass fraction of the two-dimensional graphene nanosheets is 75-90% of that of the graphene lithium ion battery cathode composite material, and the graphene nanosheets are acted on by a static magnetic field to realize directional arrangement. The preparation method of the graphene lithium ion battery cathode composite material realizes the directional arrangement of the graphene nano sheets, can construct a rapid lithium ion transmission channel, increases the distance between the graphene nano sheets, fully exerts the high specific surface area of the graphene nano sheets, and has the performance far higher than that of other graphene mixed materials.

Description

Graphene lithium ion battery cathode composite material and preparation method thereof
Technical Field
The invention belongs to the field of lithium ion battery cathode materials, and particularly relates to a graphene lithium ion battery cathode composite material and a preparation method thereof.
Background
With the exhaustion of fossil fuels and the pollution caused by them, people are gradually aware of the importance of developing new energy sources. Particularly, the popularization of new energy automobiles can effectively avoid pollution caused by fuel automobiles. The lithium ion battery has higher energy and power density, and is expected to become an ideal electrochemical energy storage system of a renewable energy factory and a power system of a hybrid vehicle and an electric vehicle. An ideal lithium ion negative electrode must have excellent specific capacity, cycling stability, and high rate performance. Although graphite is commonly used for commercial lithium ion negative electrode materials, it has many limitations. Under the condition of larger current load, the specific capacity of the battery rapidly decreases. And the theoretical capacity of graphite is only 372mAh g -1 . With the continuous development of electronic devices, especially the vigorous development of new energy sources, there is an urgent need for a stable energy storage device with high capacity and long cycle life. Graphene has high electrical conductivity, high thermal conductivity and a high specific area, and is widely applied to electrode materials of energy storage devices. However, graphene sheets are agglomerated and stacked together in a disordered manner, so that the electrochemical specific surface area of the graphene sheets is lost, and the application of graphene in electrodes is limited. When two-dimensional graphene sheets are arranged in a macroscopic order, not only can the performance of a single nano graphene sheet be fully utilized, but also the 3D structure is beneficial to the rapid transmission of lithium ions. Thus, three-dimensional ordered graphene was developedStructural electrodes are particularly important.
Graphene is a two-dimensional nanomaterial composed of carbon atoms hybridized in sp 2. The single-layer graphene has excellent conductivity, heat conductivity, carrier mobility and high specific surface area, can be used as an ideal lithium ion negative electrode material, has a theoretical capacity of 2000mAh/g, has an interlayer spacing obviously larger than that of graphite, and is more favorable for rapid insertion and extraction of lithium ions. There are studies showing the use of graphene as the negative electrode material of a battery, where the charge-discharge rate will exceed 10 times that of a lithium ion battery. However, the use of graphene as the negative electrode of a battery also brings new technical problems: there are many methods for producing graphene, and the most mainstream of the methods are a redox method and a vapor deposition method: the redox method has the advantages of low manufacturing cost and large-scale preparation, but the purity of the graphene is low, and the obtained graphene powder often contains a large amount of oxygen-containing functional groups, so that the performance of the graphene powder as a lithium ion negative electrode is reduced to a great extent; although the quality of the graphene prepared by vapor deposition is high, the manufacturing equipment is complex, the manufacturing cost of the graphene is high, and the like. Chinese invention patent CN107742746A discloses a method for preparing a film with a thickness of
Figure BDA0003809988240000021
The graphene lithium ion negative electrode prepared from the graphene has excellent rate capability and high specific capacity. However, the graphene lithium ion negative electrode obtained by the method is of a disordered three-dimensional structure, and the disordered three-dimensional structure hinders the transportation of lithium ions, so that the specific capacity and the charging and discharging efficiency of the graphene lithium ion negative electrode are only slightly improved. And the thickness of the graphene lithium ion negative electrode prepared by the method is very limited, the method is not suitable for large-scale production, is only suitable for theoretical research in a laboratory, and has very limited practical value.
In order to solve the above problems, patent CN109935793B discloses a graphene composite lithium ion battery cathode material and a preparation method thereof: secondary graphene particles are prepared through wrapping, bonding and graphitization; the inner core is made of graphite, so that the capacity is high, the rate capability is good, after the outer part is made of composite artificial graphite, the capacity is high, the charge and discharge performance is good, the particle surfaces are arranged towards all directions, the characteristic of high isotropy is achieved, and meanwhile, the secondary particle structure increases the internal gaps of the graphite. The three-dimensional structure constructs a rapid transmission channel of lithium ions, so that the lithium ions can move towards a plurality of directions to form more lithium ion migration channels, the migration path is shorter, and the high-current charge and discharge performance of graphene is improved. Patent CN112010343A discloses a preparation method of a metal oxide @ oriented graphene lithium ion battery anode material: preparing a graphene oxide aqueous solution, preparing a dispersion of graphene, a diluted salt solution and citric acid, freezing in liquid nitrogen, and annealing at high temperature to finally obtain the three-dimensional reticular graphene cathode. The test shows that the charge-discharge capacity is about 400mAh/g under the current density of 5A/g. Although the method obtains higher gravimetric capacity, the graphene metal oxide lithium ion negative electrode obtained by the method is formed under the action of the ice template, so that the volume capacity density is very low, and the cycle life is not high. Therefore, the development of a lithium ion battery cathode material with high gravimetric specific capacity, high volumetric specific capacity and high rate performance is still one of the technical problems to be solved urgently.
Disclosure of Invention
The invention aims to provide a graphene lithium ion battery negative electrode composite material and a preparation method thereof, and aims to solve the technical problem that the rate performance and specific capacity of a graphene lithium ion negative electrode are low.
In order to solve the technical problems, the specific technical scheme of the graphene lithium ion battery cathode composite material and the preparation method thereof is as follows:
firstly, the invention provides a preparation method of a graphene lithium ion battery cathode composite material, which comprises the following steps:
s1: adding two-dimensional graphene nanosheets into a dispersing agent, and uniformly dispersing the two-dimensional graphene nanosheets into the dispersing agent by using ultrasound to form a uniform graphene nanosheet dispersion solution;
s2: mixing the graphene nanosheet dispersion liquid with a high polymer base material, then adding a conductive additive, and uniformly attaching the high polymer material to the two-dimensional graphene nanosheets by using a magnetic stirrer at the temperature of 110 ℃ and at the speed of 900 rpm to obtain a uniform mixed solution;
s3: and injecting the mixed solution into a mold, applying a static magnetic field for 3-5 h, heating at a constant temperature of 50 ℃ to evaporate a dispersing agent, so that the two-dimensional graphene nanosheets are directionally arranged, and curing to obtain the directionally arranged graphene lithium ion battery cathode composite material.
Further, the static magnetic field may be generated using a ru-fe-b magnet.
Further, the intensity of the static magnetic field is 0.2 tesla or more.
The invention further provides a graphene lithium ion battery cathode composite material prepared by the method, which comprises the following steps: the graphene nano-sheet comprises two-dimensional graphene nano-sheets, a polymer matrix material, a dispersing agent and a conductive additive; the mass fraction of the two-dimensional graphene nanosheets is 75-90% of that of the graphene lithium ion battery cathode composite material, and the graphene nanosheets are subjected to action of a static magnetic field to realize directional arrangement.
Optionally, the two-dimensional graphene nanoplatelets are multi-layered graphene nanoplatelets.
Further, the number of the layers of the multilayer graphene nanosheet is 10 to 20.
Optionally, the polymer matrix material is one or more of PVDF, PVP, PEDOT: PSS.
Optionally, the dispersant is at least one of N-methylpyrrolidone and N, N-dimethylformamide, and the mass ratio of the dispersant to the graphene lithium ion battery negative electrode composite material is 100:1 to 80:1.
optionally, the conductive additive is one or more of conductive carbon, phosphorus and carbon nanotubes, and the mass fraction of the conductive additive is 10% of that of the graphene lithium ion battery negative electrode composite material.
The present invention also provides a lithium ion battery comprising: a negative electrode, a positive electrode and an electrolyte, the positive electrode being made of lithium cobaltate (LiCoO) 2 ) Lithium nickelate (LiNiO) 2 )、Nickel cobalt manganese ternary material (LiNi) x Co y Mn 1-x-y O 2 ) Lithium nickel cobalt aluminate (LiNi) 0.8 Co 0.15 Al 0.05 O 2 ) And a lithium rich manganese base (xLi) 2 MnO 3(1-x) LiMO 2 ) One or more of the materials, characterized in that the negative electrode is composed of the graphene lithium ion battery negative electrode composite material.
The graphene lithium ion battery cathode composite material and the preparation method thereof have the following advantages: (1) The two-dimensional graphene nanosheets are placed in a static magnetic field, and due to the fact that graphene has Landau diamagnetism, the two-dimensional graphene nanosheets can be subjected to a rotating moment and are converted from a high energy state to a low energy state until the orientation of the two-dimensional graphene is parallel to the direction of the magnetic field, at the moment, the energy is in the lowest state and tends to be stable, and therefore the directional arrangement of the graphene nanosheets is achieved. The graphene in the oriented arrangement can construct a rapid lithium ion transmission channel, increase the distance between graphene sheets, fully exert the advantages of high specific area and high specific capacity, and under the same condition, the performance of the obtained composite material is far higher than that of other doped and other common graphene mixed materials. (2) The two-dimensional graphene is arranged in an oriented mode, the three-dimensional structure is constructed, and the performance of the graphene is fully exerted, so that the specific capacity of the graphene lithium ion battery negative electrode composite material prepared by the method is far higher than that of the graphene lithium ion battery negative electrode composite material prepared by simple mixing under the condition of large-current charging and discharging.
Drawings
Fig. 1 is a process flow diagram of a preparation method of a graphene lithium ion battery cathode composite material according to the invention;
FIG. 2 is a schematic diagram of a preparation method of the graphene lithium ion battery negative electrode composite material of the invention;
fig. 3 is a diagram of a real object of the graphene-PVDF mixed solution obtained in example 1 of the present invention;
fig. 4 is SEM images of the graphene lithium ion battery negative electrode composite materials obtained in example 1 of the present invention and comparative example;
fig. 5 is a diagram of a substance of the graphene lithium ion battery negative electrode composite material obtained in example 1 of the present invention and a comparative example;
fig. 6 is an XRD pattern of the graphene lithium ion battery anode composite material obtained in example 1 of the present invention;
fig. 7 is a charge-discharge cycle diagram of the graphene lithium ion battery negative electrode composite material obtained in embodiment 1 of the present invention under different current levels;
fig. 8 is a cycle life diagram of the graphene lithium ion battery negative electrode composite material obtained in example 1 of the present invention at a current of 2C.
Detailed Description
In order to better understand the purpose, structure and function of the present invention, the following describes a graphene lithium ion battery negative electrode composite material and a preparation method thereof in further detail with reference to the accompanying drawings.
Firstly, the invention provides a preparation method of a graphene lithium ion battery cathode composite material, and fig. 1 is a schematic diagram of the preparation method of the graphene lithium ion battery cathode composite material in the oriented arrangement.
Specifically, firstly dispersing two-dimensional graphene nanosheets in a dispersant solution; then carrying out ultrasonic treatment for 30 minutes to form a uniform graphene nanosheet dispersion solution; then adding a polymer matrix material and a conductive additive, stirring for 30 minutes by using a magnetic stirrer at the temperature of 110 ℃ and at the speed of 900 rpm, and uniformly dispersing the polymer matrix material around the two-dimensional graphene nanosheets to finally obtain a uniform mixed solution; and then injecting the mixed solution into a mold, evaporating 80% of the dispersing agent under a magnetic field, then, under the application of a static magnetic field, standing for 3-5 hours to settle the graphene nanosheets after the graphene nanosheets are aligned, then, heating at a constant temperature of 50 ℃, and obtaining the aligned graphene lithium ion battery cathode composite material after the solvent is completely evaporated and solidified.
Wherein the static magnetic field can be provided by Ru FeB magnet. Adopt non-contact Ru ferroboron magnet to regulate and control two-dimensional graphene, avoid introducing other impurity. Under the action of a static magnetic field, the two-dimensional graphene nanosheets are directionally arranged in a three-dimensional space on one spatial dimension. Preferably, the strength of the static magnetic field is 0.2 tesla or more. FIG. 2 is a schematic diagram of the method of the present invention. Because the two-dimensional graphene nanosheets have Landau diamagnetism, the graphene nanosheets are converted from a high-energy state to a low-energy state under the action of diamagnetic force and are finally stably parallel to the direction of a magnetic field under the control of the static magnetic field, so that the graphene nanosheets are vertically and directionally arranged.
In addition, the invention also provides a graphene lithium ion battery cathode composite material, which is prepared by the method and comprises the following steps: the graphene nano-sheet comprises two-dimensional graphene nano-sheets, a polymer matrix material, a dispersing agent and a conductive additive; according to the mass percentage, the ratio of the two-dimensional graphene nanosheets to the composite material is 75-90%, and the graphene nanosheets are subjected to directional arrangement through the action of a static magnetic field.
The two-dimensional graphene nanosheet is a multilayer graphene nanosheet.
The number of the multilayer graphene nanosheets is 10-20, and the thickness of a single layer is 4-8 nm.
The polymer matrix material can be at least one of PVDF, PVP and PEDOT, PSS; the mass fraction of the high polymer matrix material is 10% -15% of the graphene lithium ion battery cathode composite material.
The dispersing agent is at least one of N-methyl pyrrolidone and N, N-dimethylformamide; the mass ratio of the dispersing agent to the two-dimensional graphene nanosheets is 100:1 to 80:1.
the conductive additive may be one or more of conductive carbon, phosphorus, or carbon nanotubes; the mass fraction of the conductive additive is 10% of that of the graphene lithium ion battery cathode composite material.
Example 1
Dispersing 100mg of two-dimensional graphene nanosheets into an N-methylpyrrolidone dispersant solution, placing the N-methylpyrrolidone dispersant solution into ultrasound for 30 minutes to obtain a uniform graphene nanosheet dispersion solution, and then adding 12.5mg of PVDF and 12.5mg of conductive carbon into the graphene solution. The mixed solution was placed in a magnetic stirrer and fully mixed at a speed of 900 rpm at 110 ℃ to obtain a graphene-PVDF mixed solution, as shown in FIG. 3. And injecting the mixed solution into the prepared mould, and respectively applying a static magnetic field of 0.3 Tesla to ensure that the graphene nano sheets are directionally arranged. The mass fraction of the two-dimensional graphene nanosheet in the graphene lithium ion battery negative electrode composite material (hereinafter referred to as composite material) obtained after evaporation of the dispersing agent is 80%, the mass fraction of the PVDF is 10%, and the mass fraction of the conductive additive is 10%.
The invention also provides comparative examples, which are identical to the respective examples except that the composite material is not treated with a static magnetic field.
The SEM image of the resulting composite material is shown in fig. 4. The left figure is a cross-sectional SEM image of the composite material obtained after static magnetic field treatment, and it can be seen from the figure that the graphene nanosheets are arranged perpendicular to the substrate, so that a rapid lithium ion transmission channel is formed. The right figure is a cross-section SEM image of the graphene lithium ion battery cathode composite material obtained in the absence of a magnetic field, and graphene nanosheets are horizontally arranged under the action of gravity and capillary force, so that the structure is not beneficial to transmission of lithium ions. That is, the alignment direction of the graphene nanoplatelets in the composite obtained in the comparative example is random. Fig. 5 is a photograph showing a physical image of the composite material obtained in example 1 and comparative example. The composite material of example 1 was a material obtained by treatment in a static magnetic field, whereas the comparative example was not treated by a static magnetic field. As can be seen from the figure, in the magnetic field treated composite, the graphene was vertically aligned and thus darker in color, while the composite not treated by the magnetic field was brighter in color because the surface reflection of the horizontally aligned graphene was more severe. FIG. 6 is an XRD spectrum of the composite material obtained in example 1 of the present invention. It can be seen from the figure that the negative electrode composite material arranged by the static magnetic field and arranged by the non-static magnetic field has diffraction peaks at about 26.5 degrees. The peak of the diffraction peak is related to the structure of the material. Since graphene nanoplatelets tend to align vertically under a static magnetic field, their diffraction peaks are weaker than those of horizontally aligned composites.
Fig. 7 is a charge-discharge cycle chart of the composite material obtained in example 1 and the comparative example as an electrode under different current levels. Wherein the load mass of the composite material cathode is about 11.2mg/cm 2 . The current of charging and discharging in the first five circles is 25/C, so that the battery is activated, and stable SEI is formed. Then circulating for 10 circles under the charging and discharging currents of 5/C, 2/C, C and 2C respectively. At 1C rate, the specific capacity of the composite negative electrode aligned by the static magnetic field is almost 3 times the capacity of the composite negative electrode not aligned under the magnetic field. The graphene negative electrode composite material arranged in the static magnetic field shows excellent rate capability.
FIG. 8 is a graph of cycle life at 2C current for example 1 and its comparative example. The first 5 cycles proceed at a slow rate of C/25, forming the SEI. Then both the static magnetic field aligned graphene negative electrode composite and the reference electrode were cycled at a rate of 2C for 200 cycles. It can be seen from the figure that the specific capacity of the graphene negative electrode composite material arranged by the static magnetic field is about 2 times that of the reference electrode. After 200 cycles, the specific capacities of the two structural electrodes are reduced, wherein the capacity retention rate of the electrode of the graphene negative electrode composite material arranged in the static magnetic field is about 85%, and the capacity retention rate of the reference electrode is about 76%.
Example 2
The PVDF from example 1 was replaced by PEDOT: PSS, and the other experimental conditions were completely identical to those of example 1.
Example 3
The PVDF in the embodiment 1 is changed into PVP, the mass fraction of the PVP is 15%, and other experimental conditions are completely consistent with those in the embodiment 1.
The graphene lithium ion battery negative electrode composite materials obtained in the embodiments 1 to 3 and the composite materials obtained in the respective comparative embodiments are assembled into a half-cell to perform a test result of constant current charging and discharging, and the test result is shown in the following table:
Figure BDA0003809988240000081
therefore, the graphene negative electrode composite material adopting the directional arrangement has more excellent rate capability than the common graphene negative electrode composite material.
The composite material can be used for a lithium ion battery, and the lithium ion battery comprises: a negative electrode, a positive electrode and an electrolytic solution, theThe positive electrode can be lithium cobaltate (LiCoO) 2 ) Lithium nickelate (LiNiO) 2 ) Nickel cobalt manganese ternary material (LiNi) x Co y Mn 1-x-y O 2 ) Lithium nickel cobalt aluminate (LiNi) 0.8 Co 0.15 Al 0.05 O 2 ) And a lithium rich manganese base (xLi) 2 MnO 3(1-x) LiMO 2 ) One or more of the materials, characterized in that the negative electrode is composed of the graphene lithium ion battery negative electrode composite material.
The moisture content in the electrolyte is less than or equal to 30ppm.
It is to be understood that the present invention has been described with reference to certain embodiments, and that various changes in the features and embodiments, or equivalent substitutions may be made therein by those skilled in the art without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims (10)

1. The preparation method of the graphene lithium ion battery cathode composite material is characterized by comprising the following steps:
s1: adding two-dimensional graphene nanosheets into a dispersing agent, and uniformly dispersing the two-dimensional graphene nanosheets into the dispersing agent by using ultrasound to form a uniform graphene nanosheet dispersion solution;
s2: mixing the graphene nanosheet dispersion liquid with a high polymer base material, then adding a conductive additive, and uniformly attaching the high polymer material to the two-dimensional graphene nanosheets by using a magnetic stirrer at the temperature of 110 ℃ and at the speed of 900 rpm to obtain a uniform mixed solution;
s3: and injecting the mixed solution into a mold, applying a static magnetic field for 3-5 h, heating at a constant temperature of 50 ℃ to evaporate a dispersing agent, so that the two-dimensional graphene nanosheets are directionally arranged, and curing to obtain the directionally arranged graphene lithium ion battery cathode composite material.
2. The preparation method of the graphene lithium ion battery cathode composite material according to claim 1, wherein the static magnetic field can be generated by Ru-Fe-B magnet.
3. The preparation method of the graphene lithium ion battery negative electrode composite material according to claim 1, wherein the intensity of the static magnetic field is greater than or equal to 0.2 tesla.
4. A graphene lithium ion battery negative electrode composite material is characterized by being prepared by the preparation method of the graphene lithium ion battery negative electrode composite material according to any one of claims 1 to 3, and comprising the following steps: the graphene nano-sheet comprises two-dimensional graphene nano-sheets, a polymer matrix material, a dispersing agent and a conductive additive; the mass fraction of the two-dimensional graphene nanosheets is 75-90% of that of the graphene lithium ion battery cathode composite material, and the graphene nanosheets are acted on by a static magnetic field to realize directional arrangement.
5. The graphene lithium ion battery negative electrode composite material of claim 4, wherein the two-dimensional graphene nanosheets are multi-layered graphene nanosheets.
6. The graphene lithium ion battery negative electrode composite material of claim 5, wherein the number of layers of the multilayer graphene nanosheets is 10-20.
7. The graphene lithium ion battery negative electrode composite material of claim 4, wherein the polymer matrix material is one or more of PVDF, PVP, PEDOT and PSS.
8. The graphene lithium ion battery negative electrode composite material of claim 4, wherein the dispersant is at least one of N-methyl pyrrolidone and N, N-dimethyl formamide, and the mass ratio of the dispersant to the graphene lithium ion battery negative electrode composite material is 100:1 to 80:1.
9. the graphene lithium ion battery negative electrode composite material of claim 4, wherein the conductive additive is one or more of conductive carbon, phosphorus and carbon nanotubes, and the mass fraction of the conductive additive is 10% of the graphene lithium ion battery negative electrode composite material.
10. A lithium ion battery comprising: a negative electrode, a positive electrode and an electrolyte, wherein the positive electrode is composed of one or more of lithium cobaltate, lithium nickelate, ternary nickel cobalt manganese material, lithium nickel cobalt aluminate and lithium rich manganese-based material, and is characterized in that the negative electrode is composed of the graphene lithium ion battery negative electrode composite material of any one of claims 4 to 9.
CN202211008841.8A 2022-08-22 2022-08-22 Graphene lithium ion battery cathode composite material and preparation method thereof Pending CN115340087A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211008841.8A CN115340087A (en) 2022-08-22 2022-08-22 Graphene lithium ion battery cathode composite material and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211008841.8A CN115340087A (en) 2022-08-22 2022-08-22 Graphene lithium ion battery cathode composite material and preparation method thereof

Publications (1)

Publication Number Publication Date
CN115340087A true CN115340087A (en) 2022-11-15

Family

ID=83953172

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211008841.8A Pending CN115340087A (en) 2022-08-22 2022-08-22 Graphene lithium ion battery cathode composite material and preparation method thereof

Country Status (1)

Country Link
CN (1) CN115340087A (en)

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106449169A (en) * 2016-08-29 2017-02-22 张德志 Method for preparing graphene-based composite material
US20170221645A1 (en) * 2014-08-11 2017-08-03 The Arizona Board Of Regents On Behalf Of The University Of Arizona Aligned graphene-carbon nanotube porous carbon composite
CN108752713A (en) * 2018-06-25 2018-11-06 厦门十维科技有限公司 One kind aligning graphene superelevation thermal conductivity composite material and preparation method
CN109722057A (en) * 2018-12-29 2019-05-07 厦门十一维科技有限公司 Graphene composite material, preparation method and its preparation facilities of high heat conductance
CN110311137A (en) * 2019-07-02 2019-10-08 宁夏汉尧石墨烯储能材料科技有限公司 A kind of anode material for lithium-ion batteries of the coated graphite alkene aligned
CN110697693A (en) * 2019-09-06 2020-01-17 广州墨羲科技有限公司 Graphene nanosheet material, and rapid manufacturing method and application thereof
JP2020043254A (en) * 2018-09-12 2020-03-19 国立研究開発法人物質・材料研究機構 Electrode using graphene, method of manufacturing the same, and power storage device using the same
CN114426691A (en) * 2022-02-11 2022-05-03 电子科技大学 Graphene electromagnetic shielding composite material and preparation method thereof

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170221645A1 (en) * 2014-08-11 2017-08-03 The Arizona Board Of Regents On Behalf Of The University Of Arizona Aligned graphene-carbon nanotube porous carbon composite
CN106449169A (en) * 2016-08-29 2017-02-22 张德志 Method for preparing graphene-based composite material
CN108752713A (en) * 2018-06-25 2018-11-06 厦门十维科技有限公司 One kind aligning graphene superelevation thermal conductivity composite material and preparation method
JP2020043254A (en) * 2018-09-12 2020-03-19 国立研究開発法人物質・材料研究機構 Electrode using graphene, method of manufacturing the same, and power storage device using the same
CN109722057A (en) * 2018-12-29 2019-05-07 厦门十一维科技有限公司 Graphene composite material, preparation method and its preparation facilities of high heat conductance
CN110311137A (en) * 2019-07-02 2019-10-08 宁夏汉尧石墨烯储能材料科技有限公司 A kind of anode material for lithium-ion batteries of the coated graphite alkene aligned
CN110697693A (en) * 2019-09-06 2020-01-17 广州墨羲科技有限公司 Graphene nanosheet material, and rapid manufacturing method and application thereof
CN114426691A (en) * 2022-02-11 2022-05-03 电子科技大学 Graphene electromagnetic shielding composite material and preparation method thereof

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
JULIETTE BILLAUD ET AL: "Magnetically aligned graphite electrodes for high-rate performance Li-ion batteries", 《NATURE ENERGY》 *
吕青;颜红侠;刘超;: "聚合物/定向石墨烯复合材料研究进展", 《工程塑料应用》 *
林峰: "磁场排列石墨烯及其性能和应用研究", 《中国博士学位论文全文数据库 工程科技Ⅰ辑》 *

Similar Documents

Publication Publication Date Title
Hou et al. Facile synthesis of LiMn0. 75Fe0. 25PO4/C nanocomposite cathode materials of lithium-ion batteries through microwave sintering
CN110690436B (en) Negative electrode material, preparation method thereof, prepared negative electrode plate and lithium ion battery
CN107204466B (en) Ultra-low temperature battery capacitor and preparation thereof
Tian et al. Synthesis and characterization of LiFePO4 electrode materials coated by graphene
CN102306783A (en) Multi-layer graphene/lithium iron phosphate intercalated composite material, preparation method thereof, and lithium ion battery adopting multi-layer grapheme/lithium iron phosphate intercalated composite material as anode material
CN102185139A (en) Preparation method of nanometer metallic oxide/graphene doped lithium iron phosphate electrode material
CN113471415A (en) Composite coated lithium ion battery anode material and preparation method thereof
Zhao et al. Effect of microstructure on low temperature electrochemical properties of LiFePO4/C cathode material
CN112271325B (en) Three-dimensional solid lithium battery and preparation method thereof
Luo et al. Carbon nanotube-modified LiFePO4 for high rate lithium ion batteries
Yang et al. Controllable synthesis of graphene nanoscroll-wrapped Fe 3 O 4 nanoparticles and their lithium-ion battery performance
CN113651304A (en) Organic carbon-coated lithium iron phosphate cathode material and preparation method thereof
CN103259002A (en) Lithium ion battery and electrode plate thereof
CN105680041A (en) Three-dimensional Na3V2(PO4)3 nanowire network electrode material and preparation method and application thereof
CN109148851B (en) Silicon-carbon composite negative electrode material modified by double carbon structure and preparation method thereof
Wang et al. Controlled synthesis of Fe3O4@ C@ manganese oxides (MnO2, Mn3O4 and MnO) hierarchical hollow nanospheres and their superior lithium storage properties
Ran et al. Grinding aid-assisted preparation of high-performance carbon-LiMnPO4
JP7188693B2 (en) Electrode using graphene, method for producing same, and power storage device using same
CN114229818A (en) Preparation method of in-situ doped graphene low-temperature lithium iron phosphate cathode material
CN114520328B (en) Lithium ion battery negative electrode material, preparation method thereof, negative electrode and battery
CN105870454A (en) Application method of graphene as conductive agent to positive electrode slurry of lithium ion battery
Xiao et al. Facile synthesis of single-crystalline Co 3 O 4 cubes as high-performance anode for lithium-ion batteries
Tian et al. One-step synthesis of SnS2 nanoflower/graphene nanocomposites with enhanced lithium ion storage performance
CN113921812B (en) Ultra-high power density sodium ion battery and preparation method thereof
CN113161157B (en) Silicon-based composite anode active material, silicon-based composite anode, and preparation method and application thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination