CH719599A1 - Flexible multi-layer structure to make a battery. - Google Patents

Abstract

A flexible multilayer structure (100) for manufacturing a rechargeable battery is disclosed. The structure (100) comprises a base and a cap, each comprising at least one polymeric layer (112, 116), a graphene layer (131, 132) and a metal layer (142, 144). The base and the cap are connected by an intermediate layer (150).

Description

TECHNICAL AREA

[0001] The present invention relates to flexible multilayer films which can be used to make a battery.

STATE OF THE TECHNIQUE

[0002] Rechargeable batteries known as “Lithium-ion” are known. It is desirable to have access to rechargeable batteries which are lighter, which store more charge and which can be recharged more quickly than known rechargeable batteries.

SUMMARY OF THE INVENTION

[0003] A flexible multilayer structure is proposed. The structure can be used to make a rechargeable battery. The structure comprises a base and a cap: the base comprising: at least one polymeric substrate layer; a first layer containing graphene; and a first metallic layer; the cap comprising: at least one polymeric passivation layer; a second layer containing graphene; and a second metallic layer; the base and the cap being connected via an intermediate layer.

[0004] According to a first embodiment, the intermediate layer is an insulating layer. The first metal layer forms a collector which can be connected to a terminal acting as a first electrode of the battery and the second metal layer forms a second collector which can be connected to a second terminal acting as a second electrode of the battery. battery. The structure can be immersed in an electrolyte to make the rechargeable battery.

[0005] According to another embodiment, the intermediate layer is a solid electrolyte and the structure can be used as the rechargeable battery.

SUMMARY DESCRIPTION OF THE DRAWINGS

[0006] The characteristics of the invention will appear more clearly on reading the description of several embodiments given solely by way of example, in no way limiting with reference to the schematic figures, in which: – FIG. 1 shows the different layers present in a flexible multilayer structure according to one embodiment of the invention; – FIG. 2 illustrates a flexible multilayer structure according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0007] The present invention relates to a flexible multilayer structure which can be used to manufacture a battery for storing and delivering electrical energy.

[0008] According to one embodiment of the invention, a flexible multilayer structure is proposed. The structure includes a plurality of layers of conductive ink, a plurality of layers of insulator, and may include an electrolytic. According to a first embodiment, the electrolyte is formed by one or more layers of dry electrolyte, the electrolyte layers forming part of the multilayer structure. According to a second embodiment, the electrolyte is a gel, liquid or otherwise wet electrolyte, in which the multilayer structure is bathed.

[0009] The production of flexible multilayer structures, according to one embodiment of the invention, can be done by printing techniques to deposit conductive inks on flexible polymer material. The production of batteries can be part of a process for producing a heating film or a process for producing flexible electronic circuits, for example. In the latter cases, it is possible to produce a battery integrated on a heating film, for example, or a battery integrated on a film comprising RFID micro-chips, for example.

[0010] Figure 1 shows an example of a multilayer structure according to one embodiment of the invention. The structure comprises a stack of layers with a substrate layer 112 at the bottom and a passivation layer 116 at the top. These layers are electrically insulating layers and can be made of an organic polymeric material, for example polyethylene terephthalate (PET). Other materials can be used, for example polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), flexible PVC (PVC-P), polystyrene (PS), polycarbonate (PC) , polymethyl methacrylate (PMMA), polyoxymethylene (POM), polyethylene terephthalate (PET), polyester, co-polyester, polyetheretherketone (PEEK), polyamide, in particular polyamide 6 (PA6), polyamide 12 (PA12), polyamide 10, polyamide 610, polyamide 66, polyamide based on aliphatic and cycloaliphatic constituents such as in particular MACM12 or amorphous co-polyamide, preferably based on PA12, or copolymers or mixtures of these.

[0011] According to one embodiment, to provide more mechanical protection and to give better electrical insulation, the substrate layer can be doubled in thickness by gluing two polymeric substrate layers together. Similarly, the passivation layer can also be doubled in thickness by gluing two polymeric passivation layers one on top of the other.

[0012] A layer of graphene 131 can be deposited on the substrate layer 112. This layer of graphene 131 can be produced by depositing, by screen printing, ink comprising graphene, for example by a slot dies process. The substrate 112 can be previously treated with a plasma to improve the adhesion of the graphene layer on the substrate. Graphene ink can be prepared by mixing graphene with resins and/or solvents.

[0013] The graphene ink layer is then dried, preferably by a near infrared ray (NIR) drying process (short waves), which promotes rapid drying of the ink without damaging the polymer. According to one embodiment, the drying is done by pulses. The inks dry at 120°C for around 10 minutes, which is much faster than other techniques without infrared rays, which can have speeds around 6 m/min for a 60m drying tunnel at 125 degrees for example. With infrared rays drying can take around one to two seconds over a distance of 0.5m or 1m.

[0014] A layer of metal 142 can be deposited on the graphene layer to serve as the battery electrode. The metal layer can be aluminum, copper or silver for example. According to another embodiment, the metal layer 142 is deposited on the substrate and the graphene layer 131 on top of the metal layer 142.

[0015] An insulating layer 150 comes on top of the metal layer. The insulating layer can be of the same material as the substrate. A second layer of graphene 132 comes after the insulating layer and then, after drying the graphene ink by infrared rays, a second layer of metal 144 is deposited to make the second electrode of the battery. This structure, once immersed in an electrolyte, will function as a rechargeable battery. According to another embodiment, the second metal layer 144 comes before the second graphene layer 132.

[0016] According to embodiments of the present invention, graphene can have a molecular structure that is hexagonal and two-dimensional, with a single layer of carbon atoms. Alternatively, graphene ink may contain microparticles, or even nanoparticles, of graphene. Graphene nanoparticles can have a size of the order of 1nm to 100nm. According to one embodiment, the molecular shape of the nanoparticles can be nanotubes, nano-spheres or graphene nano-wires, for example.

[0017] Figure 2 shows a flexible multilayer structure according to another embodiment of the invention. The structure already contains the electrolyte in a dry format and can be used directly as a rechargeable battery. The structure comprises a polymeric substrate layer 112, a metal layer 142, a graphene layer 131, a dry electrolyte layer 150, a second graphene layer 132, a second metal layer 144 and the polymeric passivation layer. The passivation and/or substrate layers can be doubled. The metal layers can be connected to two terminals to make the terminals of the rechargeable battery.

[0018] The structure can be used flat to make the battery or it can be rolled up or folded on itself.

[0019] According to one embodiment, several multilayer structures can be connected in parallel to make the rechargeable battery.

[0020] A structure according to a first embodiment of the invention can be manufactured by preparing: a base comprising the substrate 112, the first layer of graphene and the first layer of metal 142; and a cap: comprising the second layer of graphene, the second layer of metal 144 and the passivation 116. The base and the cap can then be connected via the insulating layer 150. In a second embodiment of the invention, the cap is connected to the base via the layer of dry electrolyte 250.

[0021] The cap and the base can be glued using liquid glue or a pressure-sensitive adhesive.

Claims (5)

1. Flexible multilayer structure (100, 200) for manufacturing a rechargeable battery, the structure comprising a base and a cap: the base comprising: at least one polymeric substrate layer (112, 212); a first layer containing graphene (131, 231); And a first metal layer (142, 242); the hat comprising: at least one polymeric passivation layer (116, 216); a second layer containing graphene (132, 232); And a second metal layer (144, 244); the base and the cap being connected via an intermediate layer (150, 250). 2. Structure according to claim 1, in which the intermediate layer (150) is an insulating layer. 3. Structure according to any one of claims 1 or 2, in which the intermediate layer (250) is an electrolyte. 4. Structure according to any one of the preceding claims, in which the substrate (112, 212) comprises two polymeric substrate layers and/or the passivation (116, 216) comprises two polymeric passivation layers. 5. Structure according to any one of the preceding claims, in which the substrate, the passivation and/or the insulator is: polyethylene terephthalate (PET) (polyethylene (PE), polypropylene (PP), polyvinyl chloride ( PVC), soft PVC (PVC-P), polystyrene (PS), polycarbonate (PC), polymethyl methacrylate (PMMA), polyoxymethylene (POM), polyethylene terephthalate (PET), polyester, in co-polyester, in polyetheretherketone (PEEK), in polyamide, in particular polyamide 6 (PA6), in polyamide 12 (PA12), in polyamide 10, in polyamide 610, in polyamide 66, in polyamide based on aliphatic and cycloaliphatic constituents such as in particular MACM12 or amorphous co-polyamide, preferably based on PA12, or copolymers or mixtures thereof.