KR20200140002A - Composite sheet and battery cell module using same - Google Patents

Abstract

The present invention relates to a composite sheet comprising: a laminated sheet including a graphite layer and an electrode layer; and a fluororesin-containing coating layer formed on one surface of the laminated sheet, thereby enabling high-speed heating at a low driving voltage or effectively dissipating heat from a high-temperature battery, and capable of improving durability and reliability such as light weight, chemical resistance and contamination resistance, and to a battery cell module using the same.

Description

Composite sheet and battery cell module using the same {COMPOSITE SHEET AND BATTERY CELL MODULE USING SAME}

The embodiment includes a laminated sheet and a fluororesin-containing coating layer formed on one side of the laminated sheet, thereby enabling high-speed heating at a low driving voltage, as well as effectively dissipating heat from a high-temperature battery, and has light weight, chemical resistance, and It relates to a composite sheet capable of improving durability and reliability such as fouling resistance, and a battery cell module using the same.

In electric vehicles, since the reliability and stability of the battery system act as the most important factor that determines the marketability, the proper temperature range of the battery system, 20℃ to 40℃, is maintained to prevent degradation of battery performance due to changes in various external temperatures. Should be. Accordingly, there is a need for a battery system capable of maintaining an appropriate temperature of a battery in a low temperature environment while having excellent heat dissipation performance in general climatic conditions.

In the case of a battery for an electric vehicle, a local temperature difference between battery cells may occur due to heat generated due to fast charging, high power, and repeated charging times. Accordingly, a battery system composed of a plurality of battery cells needs heat dissipation performance capable of cooling heat generated when charging or discharging the battery cells.

In addition, since electric vehicles do not have a separate internal combustion engine, they rely on heat generation using power. Since the battery capacity of electric vehicles is limited, it needs heat generation performance that can reach the appropriate temperature range in a short time. It should be able to cope with the output decrease of

Conventionally, a battery system in which coolant flows inside a heat sink made of a metal material such as aluminum or copper or a separate controller has been used. However, since a metal material such as aluminum or copper has a high thermal conductivity, the cooling effect is deteriorated, and there is a disadvantage in that the volume and weight are large, and the manufacturing cost is increased through a separate controller.

For example, Korean Patent Application Publication No. 2018-0080614 describes a battery module in which a heat exchange pad through which a cooling medium is distributed is made of a material (ceramic powder) with high heat transfer efficiency to improve cooling efficiency, but the cooling pipe of the heat exchange pad is Since it is made of aluminum or copper, it is difficult to obtain sufficient heat dissipation, space and light weight.

Republic of Korea Patent Publication No. 2018-0080614

Accordingly, the embodiment is a composite sheet capable of high-speed heating at a low driving voltage or effectively dissipating heat from a high-temperature battery, and improving durability reliability such as light weight, chemical resistance, and contamination resistance, and a battery using the same. We want to provide a cell module.

A composite sheet according to an embodiment may include a laminated sheet including a graphite layer and an electrode layer; And a fluororesin-containing coating layer formed on one surface of the laminated sheet.

A method of manufacturing a composite sheet according to an embodiment includes the steps of preparing a laminated sheet including a graphite layer and an electrode layer; And forming a fluororesin-containing coating layer on one surface of the laminated sheet.

A battery cell module according to an embodiment includes a housing; A plurality of battery cells arranged in parallel in the housing; And a composite sheet interposed between the plurality of battery cells, wherein the composite sheet includes a laminated sheet including a graphite layer and an electrode layer, and a fluororesin-containing coating layer formed on one surface of the laminated sheet.

In the composite sheet according to the embodiment, an electrode layer, a graphite layer, and a fluororesin-containing coating layer are sequentially stacked, or a graphite layer, an electrode layer, and a fluororesin-containing coating layer are sequentially stacked, thereby enabling high-speed heating at a low driving voltage and at the same time Since heat can be effectively discharged from the battery, both heat generation performance and heat dissipation performance can be improved.

1 shows a laminated structure of a composite sheet according to an embodiment.
2 shows a laminated structure of a composite sheet according to another embodiment.
3 is a schematic diagram of a surface of a graphite layer according to an embodiment.
4 shows a photograph of a surface of a graphite layer according to an embodiment.
5 is a photograph of a surface of a graphite layer according to an embodiment observed with an atomic force microscope (AFM).

Hereinafter, the invention will be described in detail through embodiments. The implementation is not limited to the content disclosed below, and may be modified in various forms unless the gist of the invention is changed.

In the present specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated.

In addition, all numbers and expressions representing amounts of components, reaction conditions, and the like described in the present specification are to be understood as being modified by the term "about" in all cases unless otherwise specified.

Composite sheet

A composite sheet according to an embodiment may include a laminated sheet including a graphite layer and an electrode layer; And a fluororesin-containing coating layer formed on one surface of the laminated sheet.

According to one embodiment, the fluororesin-containing coating layer is formed on the graphite layer.

1 shows a laminated structure of a composite sheet according to an embodiment. 1 illustrates a composite sheet in which a fluororesin-containing coating layer is formed on one surface of a laminated sheet in which a graphite layer is stacked on an electrode layer. Specifically, an electrode layer, a graphite layer, and a fluororesin-containing resin layer may be sequentially stacked.

According to another embodiment, the fluororesin-containing coating layer is formed on the electrode layer.

2 shows a laminated structure of a composite sheet according to another embodiment. 2 illustrates a composite sheet in which a fluororesin-containing coating layer is formed on one surface of a laminated sheet in which an electrode layer is stacked on a graphite layer. Specifically, a graphite layer, an electrode layer, and a fluororesin-containing resin layer may be sequentially stacked.

In the composite sheet according to the embodiment, an electrode layer, a graphite layer, and a fluororesin-containing coating layer are sequentially stacked, or a graphite layer, an electrode layer, and a fluororesin-containing coating layer are sequentially stacked, thereby enabling high-speed heating at a low driving voltage and at the same time Since heat can be effectively discharged from the battery, both heat generation performance and heat dissipation performance can be improved.

In addition, since the composite sheet is not bulky, it is possible to improve durability reliability such as chemical resistance and fouling resistance by including a fluororesin-containing coating layer having excellent light weight and excellent chemical resistance such as flame retardancy.

According to one embodiment, the thickness of the composite sheet is 10 to 500 ㎛. Specifically, the thickness of the composite sheet may be 50 to 500 µm, 70 to 500 µm, 70 to 300 µm, 10 to 300 µm, 10 to 250 µm, or 70 to 250 µm.

Graphite layer

The thermal conductivity of a metal material such as aluminum or copper is isotropic, whereas the graphite layer has different thermal conductivity in the thickness direction and the surface direction due to the structure of graphite particles having an anisotropic arrangement.

Specifically, the graphite layer generally has a thermal conductivity of 100 W/mk or more in a plane direction, and a thermal conductivity of 20 W/mk or less in a horizontal direction. Accordingly, since the graphite layer can rapidly transfer heat generated from a plurality of battery cells to a lower heat sink, heat dissipation can be improved.

According to an embodiment, a ratio of thermal conductivity in a plane direction to thermal conductivity in a thickness direction of the graphite layer may be 300 or more. Specifically, the thermal conductivity in the thickness direction of the graphite layer may be 1 W/mK to 20 W/mK, and the thermal conductivity in the plane direction may be 800 W/mK to 2,000 W/mK. For example, the thermal conductivity in the thickness direction may be 1 W/mK to 18 W/mK, 3 W/mK to 20 W/mK, or 5 W/mK to 20 W/mK, and the thermal conductivity in the plane direction May be 900 W/mK to 2,000 W/mK, 1,000 W/mK to 1,800 W/mK, 1,200 W/mK to 2,000 W/mK, or 1,200 W/mK to 1,800 W/mK.

According to one embodiment, the graphite layer may include a stack of five or more layers in which at least one first graphite layer and at least one second graphite layer are alternately stacked.

The graphite layer has a fabric-like surface structure in which weft and warp are woven. Specifically, the graphite layer may include a first graphite layer and a second graphite layer including graphitized fibers. More specifically, the graphite layer may include a first graphite layer including graphitized fibers and a second graphite layer covering one side or both sides of the first graphite layer.

The surface structure of the graphite layer may be the same as the surface of the fibers forming the first graphite layer. The fiber is a fabric substrate, and may be a substrate having a woven structure in which the surface structure of the graphite layer prepared using the same has the above-described structure.

The first graphite layer may include a fiber bundle including a plurality of graphite fibers. Specifically, the first graphite layer may be formed of a fiber bundle including a plurality of graphite fibers. In addition, the fiber bundle may include voids formed between a plurality of graphite fibers. Further, the first graphite layer may include a fabric form in which a weft yarn and a warp are woven made of graphite fibers or graphite fiber bundles.

The first graphite layer may include fibers in which natural fibers or artificial fibers are graphitized. Specifically, the first graphite layer may be a fiber in which natural fibers or artificial fibers are carbonized and graphitized.

The natural fiber may be at least one selected from the group consisting of cellulose fibers, protein fibers, and mineral fibers. The cellulose fibers are, for example, (i) seed fibers such as cotton or kapok, (ii) stem fibers such as flax, germ, hemp, or jute, (iii) fruit fibers such as palm fibers, and (iv) And leaf fibers such as manila hemp, abaca, or sisalma. Further, the protein fibers include, for example, (i) wool fibers, (ii) silk fibers and (iii) hair fibers. The mineral fibers include, for example, (i) artificial mineral fibers such as glass wool and mineral wool, and (ii) asbestos fiberized by liquefaction of glass, rock, and other minerals at high temperatures. Specifically, the natural fiber may include one or more selected from the group consisting of cotton, hemp, wool and silk.

The artificial fiber may be at least one selected from the group consisting of organic fibers and inorganic fibers. The organic fibers include, for example, (i) cellulose-based fibers such as rayon, tencel (lyocell), modal, etc., or regenerated fibers including protein-based fibers, (ii) cellulose fibers such as acetate, triacetate, etc. Semi-synthetic fibers, or (iii) polyamide fibers, polyester fibers, polyurethane fibers, polyethylene fibers, polyvinyl chloride fibers, polyfluoroethylene fibers, polyvinyl alcohol fibers, acrylic fibers or polypropylene Synthetic fibers such as fiber based fibers are mentioned. Specifically, the artificial fiber is at least one synthetic fiber selected from the group consisting of nylon, polyester, polyurethane, polyethylene, polyvinyl chloride, polyfluoroethylene, polyvinyl alcohol, acrylic and polypropylene; Or it may include one or more cellulose-based fibers selected from the group consisting of rayon, acetate, and triacetate.

For example, the first graphite layer may include a lattice structure having a pitch of 20 to 200 μm and a width of 60 to 200 μm.

The second graphite layer may cover one side or both sides of the first graphite layer. Specifically, the second graphite layer is composed of a first graphite outer layer coated on one side of the first graphite layer and a second graphite outer layer coated on the other side of the first graphite layer, and the first graphite outer layer and the second graphite outer layer Some of the outer layers of graphite may be connected to each other.

The second graphite layer may be a polymer resin graphitized. In addition, the second graphite layer may include natural graphite or expanded graphite.

The polymer resin may include one or more of the group consisting of polyimide, polyamic acid, polyvinyl chloride, polyester, polyurethane, polyethylene, polyfluoroethylene, polyvinyl alcohol, acrylic and polypropylene. Specifically, the polymer resin may include one or more of the group consisting of polyimide, polyamic acid, and polyvinyl chloride having a weight average molecular weight of 200,000 to 300,000 g/mol.

Specifically, the graphite layer may be prepared by preparing a fiber substrate and a laminate including a polymer coating layer on one or both sides of the fiber substrate, and then carbonizing and graphitizing the laminate integrally. By carrying out a process of carbonizing and graphitizing at a predetermined temperature, both the fiber base material and the polymer coating layer forming the laminate are graphitized, thereby producing a graphite layer.

When the graphite layer is manufactured by graphitizing the laminate as described above, there is an advantage that a graphite layer having a relatively thick thickness and excellent thermal conductivity can be manufactured inexpensively.

In this case, the thickness of one of the polymer coating layers may be 30 to 50 μm. For example, when the polymer coating layer is formed on both sides of the fiber substrate, the total thickness of the polymer coating layer of the second layer may be 60 to 100 μm. When the thickness of the polymer coating layer is formed in the above thickness range, the laminate may have a woven structure derived from the fibrous substrate on the surface of the graphite layer after carbonization and graphitization.

The fiber substrate may be one or more selected from the group consisting of natural fibers and artificial fibers. The natural fibers and artificial fibers are as described in the first graphite layer.

The polymer coating layer is as described in the polymer resin of the graphite second graphite layer.

In addition, the graphite layer may include a grid structure having a pitch of 20 to 200 μm and a width of 60 to 200 μm.

3 and 4, the graphite layer may have a surface structure in the form of a fabric in which weft and warp are woven.

In this case, the widths d1 and d2 of the weft (A) and the warp (B) may be 20 to 200 μm, 30 to 170 μm, or 50 to 170 μm, respectively. In addition, the weft (A) and the warp (B) may have a pitch (P1, P2) of 20 to 200 µm, 30 to 170 µm, or 50 to 170 µm, respectively.

In addition, the surface structure of the graphite layer may satisfy a weft (A) X warp (B) of 80 to 130 X 100 to 150 count/inch. For example, the surface structure of the graphite layer may satisfy a weft (A) X warp (B) of 130 X 150 count/inch, 100 X 120 count/inch, or 80 X 100 count/inch.

The graphite layer may have a predetermined roughness on the surface by having the above-described surface structure. Specifically, referring to FIG. 3, a level difference occurs between a portion C where the weft yarn A and the warp yarn B overlap and a portion D that does not overlap the surface of the graphite layer.

According to one embodiment, the surface roughness Ra of the graphite layer may be 0.5 to 10 μm (see FIG. 5). More specifically, the surface roughness (Ra) of the graphite layer may be 1 to 8 µm, or 2 to 6 µm.

According to one embodiment, the thickness of the graphite layer is 10 μm to 500 μm. Specifically, the thickness of the graphite layer may be 50 to 500 µm, 70 to 500 µm, 70 to 300 µm, 10 to 300 µm, 10 to 250 µm, or 70 to 250 µm. When the thickness of the graphite layer is within the above range, it may be advantageous in terms of heat capacity.

The graphite layer has a bending radius of 5 mm (R), a bending angle of 180°, a load of 0.98 N, and a bending speed of 90 times/min. It can be more than that. Specifically, the graphite layer may have a reciprocating bending number of 10,000 to 20,000 times, 10,000 to 18,000 times, or 10,000 to 15,000 times as a result of the MIT flexibility test.

The graphite layer may have a specific heat of 0.5 to 1.0 J/gK, 0.5 to 0.9 J/gK, 0.6 to 0.9 J/gK, or 0.7 to 0.9 J/gK at 50°C. The density of the graphite layer may be 0.5 to 2.5 g/cm 3, 0.5 to 2.0 g/cm 3, or 0.8 to 2.0 g/cm 3.

According to one embodiment, the density of the second graphite layer may be higher than that of the first graphite layer. Specifically, the density of the first graphite layer may be 1.3 to 1.5 g/cm 3 or 1.5 to 1.9 g/cm 3, and the density of the second graphite layer may be 1.5 to 1.8 g/cm 3 or 1.8 to 2.1 g/cm 3 .

The composite sheet according to the embodiment may improve heat dissipation performance by including the graphite layer. Specifically, by including a graphite layer rather than a conventional metal material, there is an advantage in that the volume is small, light and flexible compared to the metal material. In addition, since heat can be effectively discharged from a high-temperature battery, heat dissipation performance can be improved.

Electrode layer

According to one embodiment, the electrode layer may include silver-nanowire (Ag-nanowire), a metal mesh, indium tin oxide (ITO), or a combination thereof.

According to one embodiment, the sheet resistance of the electrode layer may be 50 Ω/□ or less. Specifically, when the electrode layer includes silver-nanowire (Ag-nanowire) or metal mesh (metal mesh), the sheet resistance of the electrode layer is 40 Ω/□ or less, 30 Ω/□ or less, 20 Ω/□ or less, or It may be less than 10 Ω/□. In addition, when the electrode layer includes indium tin oxide, the sheet resistance of the electrode layer is 50 Ω/□ or less, 40 Ω/□ or less, 30 Ω/□ or less, 20 Ω/□ or less, or 10 Ω/ It can be less than □.

According to one embodiment, the thickness of the electrode layer may be 1 to 1000 nm. For example, the thickness of the electrode layer is 10 to 1000 nm, 20 to 1000 nm, 30 to 1000 nm, 50 to 1000 nm, 80 to 1000 nm, 100 to 1000 nm, 100 to 900 nm, 100 to 800 nm, 150 To 800 nm, 200 to 800 nm, 200 to 600 nm, or 200 to 500 nm.

The composite sheet according to the embodiment may improve the heat generation performance by including the electrode layer. Specifically, since high-speed heating is possible with a low driving voltage, heat generation performance can be improved.

Fluorine resin-containing coating layer

According to one embodiment, the fluororesin-containing coating layer is polytetrafluoroethylene (PTFE, polytetrafluoroethylene), polychlorotrifluoroethylene (PCTFE), polyvinylidenedifluoride (PVDF), florinization. Selected from the group consisting of ethylene propylene copolymer (FEP), polyethylene-co-tetrafluoroethylene (ETFE), and polyethylene-co-chlorotrifluoroethylene (ECTFE). It may contain one or more.

According to one embodiment, the fluororesin-containing coating layer may further include at least one conductive polymer selected from the group consisting of carbon nanotubes, carbon nanofibers, carbon fibers, and graphene.

According to one embodiment, the contact angle of the fluororesin-containing coating layer may be 90° or more. For example, the contact angle of the fluororesin-containing coating layer may be 100° or more, 110° or more, or 120° or more.

According to one embodiment, the thickness of the fluororesin-containing coating layer may be 1 to 1000 nm. For example, the thickness of the fluororesin-containing coating layer is 10 to 1000 nm, 20 to 1000 nm, 30 to 1000 nm, 50 to 1000 nm, 80 to 1000 nm, 100 to 1000 nm, 100 to 900 nm, 100 to 800 nm, 150 to 800 nm, 200 to 800 nm, 200 to 600 nm, or 200 to 500 nm.

The composite sheet according to the embodiment includes a coating layer containing a fluorine resin having excellent chemical resistance such as flame retardancy, and thus durability reliability such as chemical resistance and fouling resistance may be improved.

Manufacturing method of composite sheet

A method of manufacturing a composite sheet according to an embodiment includes the steps of preparing a laminated sheet including a graphite layer and an electrode layer; And forming a fluororesin-containing coating layer on one surface of the laminated sheet.

The contents of the graphite layer, the electrode layer and the fluororesin-containing coating layer are the same as described above.

According to one embodiment, the electrode layer may be formed by a wet coating process or a sputtering process, and the fluororesin-containing coating layer may be formed by a sputtering process.

The sputtering process may be performed using radio frequency (RF), middle frequency (MF), or dirt current (DC), but is not limited thereto.

Battery cell module

A battery cell module according to an embodiment includes a housing; A plurality of battery cells arranged in parallel in the housing; And a composite sheet interposed between the plurality of battery cells, wherein the composite sheet includes a laminated sheet including a graphite layer and an electrode layer, and a fluororesin-containing coating layer formed on one surface of the laminated sheet.

In the battery cell module according to an embodiment, the other surface of the laminated sheet may contact the individual battery cells.

In the conventional battery cell module, a cooling fin is interposed between a plurality of battery cells in order to move heat generated from the battery cell to a heat sink, and the heat moving along the cooling fin is transferred to a heat sink through which coolant flows inside the battery cell. It is possible to maintain the management temperature (20 ℃ to 40 ℃) of the module.

However, in such a conventional battery cell module, since the housing, cooling fins, and heat sink are made of metal having high thermal conductivity such as aluminum or copper, sufficient heat dissipation cannot be obtained.

In addition, a conventional general lithium-ion battery may degrade the output performance of a vehicle in a low-temperature environment. Specifically, the output performance starts to deteriorate from below 10℃, and the performance decreases by 30% at -20℃, so that heating can be performed at the management temperature (20℃ to 40℃) of the battery cell module in a low-temperature environment. You need a heating device.

The battery cell module according to the embodiment includes a composite sheet in which an electrode layer, a graphite layer, and a fluororesin-containing coating layer are sequentially stacked, or a composite sheet in which a graphite layer, an electrode layer, and a fluororesin-containing coating layer are sequentially stacked, High-speed heating is possible with the driving voltage, and at the same time, heat can be effectively dissipated from the high-temperature battery, thereby improving both heat generation performance and heat dissipation performance.

In addition, since the battery cell module according to an embodiment is not bulky, it includes a graphite sheet having excellent light weight, so that the number of battery cells installed in the same space as the conventional battery cell module can be increased, thereby reducing the amount of power of the battery cell module. Can be increased and has excellent flexibility.

In addition, the battery cell module according to the embodiment includes a composite sheet including a fluororesin-containing coating layer having excellent chemical resistance such as flame retardancy, and thus durability reliability such as chemical resistance and fouling resistance may be improved.

housing

The housing is for fixing a plurality of battery cells and a heat radiation sheet. For example, the housing is preferably a metal material such as aluminum or a plastic material such as PC+ABS, PA, or PP, and preferably has functions such as flame retardancy, chemical resistance, insulation, and durability, but is not limited thereto.

Battery cell

According to one embodiment, a plurality of battery cells are arranged in parallel in the housing. Specifically, since the number of battery cells is determined according to the amount of power required, a larger amount of power can be supplied as more battery cells are disposed.

The battery cell module according to the exemplary embodiment includes a graphite layer, not a conventional metal material, and thus has a smaller volume than that of a metal material. Accordingly, since the number of installed battery cells can be increased in the same space as the conventional battery cell module, the amount of power of the battery cell module can be increased. Furthermore, compared to metal materials, it has the advantage of being light and flexible.

The description of the composite sheet is the same as described above.

According to one embodiment, the sheet resistance of the battery cell module may be 50 Ω/□ or less. For example, the sheet resistance of the battery cell module may be 40 Ω/□ or less, 30 Ω/□ or less, 20 Ω/□ or less, or 10 Ω/□ or less.

According to one embodiment, the battery cell module may reach a temperature of 60°C to 100°C within 20 seconds. For example, the battery cell module may reach a temperature of 60°C to 90°C or 60°C to 80°C within 20 seconds.

According to one embodiment, the temperature increase rate of the battery cell module may be 1.5 to 2°C/sec. For example, the heating rate of the battery cell module may be 1.6 to 2°C/sec or 1.5 to 1.8°C/sec.

Claims (18)

A laminated sheet including a graphite layer and an electrode layer; And
Containing a fluororesin-containing coating layer formed on one surface of the laminated sheet. The method of claim 1,
The composite sheet, wherein a ratio of the thermal conductivity in the plane direction to the thermal conductivity in the thickness direction of the graphite layer is 300 or more. The method of claim 1,
The thermal conductivity of the graphite layer in the plane direction is 800 to 2,000 W/mK, a composite sheet. The method of claim 1,
The composite sheet, wherein the fluororesin-containing coating layer is formed on the electrode layer. The method of claim 1,
The composite sheet, wherein the fluororesin-containing coating layer is formed on the graphite layer. The method of claim 1,
The fluororesin-containing coating layer is polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidenedifluoride, fluorinated ethylene propylene copolymer, polyethylene -Tetrafluoroethylene (polyethylene-co-tetrafluoroethylene) and polyethylene-chlorotrifluoroethylene (polyethylene-co-chlorotrifluoroethylene) comprising at least one selected from the group consisting of, a composite sheet. The method of claim 6,
The fluororesin-containing coating layer further comprises at least one conductive polymer selected from the group consisting of carbon nanotubes, carbon nanofibers, carbon fibers, and graphene. The method of claim 1,
The composite sheet, wherein the contact angle of the fluororesin-containing coating layer is 90° or more. The method of claim 1,
The electrode layer is a silver-nanowire (Ag-nanowire), a metal mesh (metal mesh), indium tin oxide (indium tin oxide) or a combination thereof, comprising a composite sheet. The method of claim 1,
The thickness of the graphite layer is 10 to 500 μm,
The composite sheet, wherein the electrode layer and the fluororesin-containing coating layer each have a thickness of 1 to 1000 nm. The method of claim 1,
The composite sheet has a thickness of 10 to 500 μm. Manufacturing a laminated sheet including a graphite layer and an electrode layer;
Forming a fluororesin-containing coating layer on one side of the laminated sheet; containing, a method for producing a composite sheet. The method of claim 12,
The electrode layer is formed by a wet coating process or a sputtering process,
The method for producing a composite sheet, wherein the fluororesin-containing coating layer is formed by a sputtering process. housing;
A plurality of battery cells arranged in parallel in the housing; And
Including a composite sheet interposed between the plurality of battery cells,
The battery cell module, wherein the composite sheet includes a laminated sheet including a graphite layer and an electrode layer, and a fluororesin-containing coating layer formed on one surface of the laminated sheet. The method of claim 14,
The battery cell module, wherein the other surface of the laminated sheet is in contact with the individual battery cells. The method of claim 14,
The battery cell module, wherein the sheet resistance of the battery cell module is 50 Ω/□ or less. The method of claim 14,
The battery cell module reaches a temperature of 60 ℃ to 100 ℃ within 20 seconds, the battery cell module. The method of claim 14,
The battery cell module, wherein the temperature increase rate of the battery cell module is 1.5 to 2°C/sec.

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