Composite current collector for battery

Abstract

The utility model discloses a composite current collector for a battery, which comprises a base film layer, aluminum film layers are formed on the front side and the back side of the polymer base film layer in a film coating mode, and copper film layers are formed on the surfaces of the aluminum film layers on the front side and the back side in a film coating mode. The aluminum film layer and the copper film layer are sequentially formed on the surface of the base film layer in a film coating mode and the like, and compared with the mode that a battery current collector in the prior art only uses a copper coating film or a copper foil, the multi-layer structure of high molecules, the aluminum layer and the copper layer is adopted, so that the cost is saved and the safety of the battery is improved on the premise that the actual use effect of the battery is not influenced.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a composite current collector for batteries. Background Art

[0002] Composite current collector is a new type of battery current collector material, which is composed of polymer materials and metals. It mainly collects current and carries positive and negative active substances. The structure of this composite current collector is similar to a "sandwich" structure, with a base film (such as PP, PET, PI and other polymer materials) in the middle and copper-plated metal films on the outside.

[0003] The conventional technology generally adopts the method of evaporation plating (copper plating) equipment plus water electroplating (copper plating) to achieve the effect. Water electroplating generally has pollution problems, and the overall copper plating cost is relatively high.

[0004] Therefore, those skilled in the art provide a composite negative electrode current collector to solve the problems raised in the above background technology. Utility Model Content

[0005] The utility model aims to solve the shortcomings in the prior art and proposes a composite current collector for a battery.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A composite current collector for a battery comprises a base film layer, wherein an aluminum film layer is formed on both sides of the base film layer by evaporation coating or magnetron sputtering, and a copper film layer is formed on both sides of the aluminum film layer by evaporation coating or magnetron sputtering.

[0008] Preferably, the base film layer is made of any one of the polymer materials selected from the group consisting of PP (polypropylene), PET (polyester of terephthalate), PI (polyimide), PETF (polytetrafluoroethylene), PE (polyethylene), PA (polyamide), PS (polystyrene), PVC (polyvinyl chloride), ABS (acrylonitrile-butadiene-styrene copolymer), PBT (polybutylene terephthalate), PPTA (polyparaphenylene terephthalamide), EPR (polypropylene), and PC (polycarbonate).

[0009] Preferably, the base film layer has a thickness of 0-10 um.

[0010] Preferably, the aluminum film layer is made of aluminum and its alloys, and the thickness of the aluminum film layer is 0-10 um.

[0011] Preferably, the copper film layer is made of copper and its alloys, and the thickness of the copper film layer is 0-5um.

[0012] Compared with the prior art, the beneficial effects of the utility model are:

[0013] The utility model forms an aluminum film layer and a copper film layer on the surface of the base film layer in sequence by means of evaporation coating or magnetron sputtering. Compared with the prior art method in which the current collector only uses copper foil or copper plating, the present application uses a multilayer structure of polymer + aluminum + copper layer, which saves costs and improves the safety of the battery without affecting the actual use effect of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more specifically and intuitively illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0015] Figure 1 It is a schematic diagram of the structure proposed by the utility model;

[0016] Figure 2 The utility model proposes Figure 1 A is an enlarged structural diagram;

[0017] Figure 3 This is a schematic diagram of the molding base film structure proposed by the utility model.

[0018] In the figure: 1. Equipment body; 2. Partition; 3. Aluminum plating evaporation source; 4. Copper plating evaporation source; 5. Unwinding roll; 6. Pre-treated base film; 7. Coating roller; 8. Discharge hole; 9. Movable roller; 10. Rewinding roll; 1101. Base film layer; 1102. Aluminum plating layer; 1103. Copper plating layer; 12. First guide roller; 13. Anti-wear roller; 14. Steering roller; 15. Correction roller; 16. Second guide roller. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0020] Example, see Figure 1-3 :

[0021] A composite current collector for a battery, comprising a base film layer 1101, an aluminum film layer 1102 is formed on both the front and back sides of the base film layer 1101 by coating, and a copper film layer 1103 is formed on both the front and back sides of the aluminum film layer 1102 by coating;

[0022] A composite current collector coating device for a battery comprises an equipment body 1, a partition 2 is arranged at the middle of the inner side of the equipment body 1, and the inner side of the equipment body 1 is divided into an aluminum coating chamber and a copper coating chamber by the partition 2, aluminum coating evaporation sources 3 are installed at the upper and lower sides of the inner side of the aluminum coating chamber, copper coating evaporation sources 4 are installed at the upper and lower sides of the inner side of the copper coating chamber, a discharge roll 5 is arranged on the left side of the aluminum coating chamber, and a take-up roll 10 is arranged on the right side of the copper coating chamber, coating rollers 7 are installed on the two aluminum coating evaporation sources and the two copper coating evaporation sources 4, a discharge hole 8 is opened on the partition 2, and movable rollers 9 are rotatably arranged at the upper and lower sides of the inner side of the discharge hole 8, a pre-treated base film 6 is released from the outer side of the discharge roll 5, the pre-treated base film 6 passes through the coating rollers 7 on the aluminum coating evaporation source 3 and the copper coating evaporation source 4 from left to right in turn, and the current collector formed by coating is rolled up on the take-up roll 10, a first steering roller 14 is installed between the two coating rollers 7 in the aluminum coating chamber and the copper coating chamber, and the pre-treated base film 6 bypasses the top of the steering roller 14;

[0023] The coating method of the coating device is:

[0024] The evaporation source is a magnetron sputtering source, the positive pole of the magnetron sputtering power source is connected to the device body 1, the negative pole is connected to the magnetron sputtering source, cooling water is introduced into the steering roller to dissipate heat for the pre-treated base film 6, the steering roller is connected to the bias power source, the negative pole of the bias power source is connected to the steering roller, and the positive pole is connected to the device body 1;

[0025] The inside of the equipment body 1 is evacuated to below 0.01Pa by a vacuum pump group, and then argon gas is introduced to adjust the pressure in the equipment body 1 from 0.01Pa to 1Pa, and the magnetron sputtering power supply is turned on and adjusted to the power mode. According to the winding speed and the coating thickness requirements, the power of the magnetron sputtering power supply is set to 2kw-20kw, and the bias power supply is turned on at the same time. The bias power supply is set to the voltage mode and the voltage is set to 50V-600V;

[0026] Start the unwinding reel 5 and the receiving reel 10 to transport the pretreated base film 6 along the travel direction inside the equipment body 1, and coat the aluminum film layer 1102 and the copper film layer 1103 on both sides of the pretreated base film 6 in turn through two aluminum coating evaporation sources 3 and two copper coating evaporation sources 4.

[0027] As can be seen from the figure, the technical solution adopted above is that the same two evaporation sources are symmetrically arranged on a vertical plane, so that both sides of the pre-treated base film 6 can be coated. By arranging two evaporation sources on the inner side of the equipment body 1, the pre-treated base film 6 passes through the aluminum plating evaporation source 3 and the copper plating evaporation source 4 in turn, so that an aluminum layer and a copper layer are formed on its surface, and the copper layer is on the outside. Compared with the traditional structure, the amount of copper is saved, the cost is reduced, and the pollution is reduced. The coating thickness can be adjusted according to the actual situation.

[0028] The base film layer (1101) is made of any one of the polymer materials selected from the group consisting of PP (polypropylene), PET (polyester of terephthalate), PI (polyimide), PETF (polytetrafluoroethylene), PE (polyethylene), PA (polyamide), PS (polystyrene), PVC (polyvinyl chloride), ABS (acrylonitrile-butadiene-styrene copolymer), PBT (polybutylene terephthalate), PPTA (polyparaphenylene terephthalamide), EPR (polypropylene), and PC (polycarbonate);

[0029] The base film layer (1101) has a thickness of 0-10 um;

[0030] The aluminum film layer (1102) is made of aluminum and its alloy, and the thickness of the aluminum film layer (1102) is 0-10 um;

[0031] The copper film layer (1103) is made of copper and its alloys, and the thickness of the copper film layer (1103) is 0-5um.

[0032] The tops of the aluminum evaporation source 3 and the copper evaporation source 4 are located on both sides of the coating roller 7 and are equipped with first guide rollers 12 through brackets. The tops of the aluminum evaporation source 3 and the copper evaporation source 4 are equipped with anti-wear rollers 13 near the corners of the coating roller 7.

[0033] In the technical solution adopted above, the function of the first guide rollers 12 on both sides is to ensure a better travel route for the pre-treated base film 6 and to ensure the stability of its inlet and outlet ends, and to prevent the pre-treated base film 6 from being worn at the corners of the equipment through the function of the anti-wear rollers 13.

[0034] A plurality of groups of correcting rollers 15 are arranged inside the equipment body 1, each group of correcting rollers 15 is provided with two, and the two correcting rollers 15 are arranged on both sides of the pre-treated base film 6 respectively, and second guide rollers 16 are symmetrically arranged on both sides of the partition inside the equipment body 1, and the second guide rollers 16 are higher than the upper movable roller 9 on the vertical plane;

[0035] In the technical solution adopted above, the deviation correction rollers 15 are located on both sides of the pre-treated base film 6 to prevent it from deviating during movement, and the second guide rollers 16 enable the pre-treated base film 6 to smoothly transition from the aluminum plating chamber to the copper plating chamber.

[0036] The evaporation source in the technical solution adopted above is only a technical illustration, and can be realized by various coating methods such as evaporation coating or magnetron sputtering, for example, thermal evaporation coating, electron beam evaporation coating, multi-arc evaporation coating or magnetron sputtering.

[0037] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A composite current collector for a battery, comprising a base film layer (1101), characterized in that: The front and back surfaces of the base film layer (1101) are both coated to form an aluminum film layer (1102), and the front and back surfaces of the aluminum film layer (1102) are both coated to form a copper film layer (1103).

2. A composite current collector for a battery according to claim 1, characterized in that: The base film layer (1101) is made of any one of the polymer materials selected from the group consisting of PP (polypropylene), PET (polyethylene terephthalate), PI (polyimide), PETF (polytetrafluoroethylene), PE (polyethylene), PA (polyamide), PS (polystyrene), PVC (polyvinyl chloride), ABS (acrylonitrile-butadiene-styrene copolymer), PBT (polybutylene terephthalate), PPTA (polyparaphenylene terephthalamide), EPR (polypropylene), and PC (polycarbonate).

3. A composite current collector for a battery according to claim 1, characterized in that: The base film layer (1101) has a thickness of 0-10 um.

4. A composite current collector for a battery according to claim 1, characterized in that: The aluminum film layer (1102) is made of aluminum and its alloys, and has a thickness of 0-10 um.

5. A composite current collector for a battery according to claim 1, characterized in that: The copper film layer (1103) is made of copper and its alloys, and the thickness of the copper film layer (1103) is 0-5 um.

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