Composite current collector, preparation method thereof and lithium battery pole piece

A current collector and lithium battery technology, which is applied to battery electrodes, non-aqueous electrolyte battery electrodes, secondary batteries, etc., can solve the problems of large influence of welding effect on pole pieces and internal resistance of batteries, reducing battery energy density, increasing battery weight, etc. , to achieve the effect of improving physical and chemical properties, increasing electronic channels, and reducing battery weight

Inactive Publication Date: 2020-11-03
HEFEI GUOXUAN HIGH TECH POWER ENERGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, metal tabs and composite current collectors are two foils of different materials. The welding effect has a great influence on the internal resistance of the pole piece and the battery, and the introduction of metal tabs will increase the weight of the battery and reduce the energy density of the battery.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] A method for preparing a composite current collector, comprising the steps of:

[0019] Take a porous polyethylene terephthalate film with a thickness of 3 μm, a micropore diameter of 25 μm, and a center-to-center spacing of 60 μm, and perform plasma cleaning to ensure that the surface has sufficient adhesion and is compatible with metals. The coating is tightly bonded;

[0020] Then adjust the vacuum to 10 -4 Pa, vacuum-evaporated metal aluminum on the surface of porous polyethylene terephthalate film to obtain an aluminum coating with a thickness of 1 μm;

[0021] Then, a layer of carbon black with a thickness of 1 μm was coated on the surface of the aluminum coating as a conductive coating to obtain a composite current collector.

Embodiment 2

[0031] A method for preparing a lithium battery positive electrode sheet, comprising the steps of: taking the composite current collector described in Example 1, and coating the positive electrode slurry containing the positive electrode active material on the surfaces of both sides of the composite current collector (compared to the composite current collector The thickness of the fluid, the thickness of the active material layer is relatively large, so after coating, the surface of the current collector is very flat), and then vacuum baked in an oven at 100 ° C for 12 hours, rolled, and then slitting, laser cutting or mold Cut the positive pole piece;

[0032] Wherein, the preparation method of the positive electrode slurry is: adding the positive electrode active material (the positive electrode active material is nickel cobalt lithium manganese oxide NCM622), the conductive agent CNTs, and the binder PVDF into the organic solvent NMP according to the weight ratio of 97.8:1....

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PUM

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Abstract

The invention discloses a composite current collector which comprises a porous polymer film, a metal coating attached to the surface of the porous polymer film and a conductive coating attached to thesurface of the metal coating. The invention also discloses a preparation method of the composite current collector. The invention also discloses a lithium battery pole piece. According to the presentinvention, the ultra-thin porous polymer film is adopted, so that the physical and chemical properties of the current collector can be improved, belt breakage is reduced, the weight of the battery can be reduced, and the energy density of the battery is improved; after the ultrathin porous polymer film is plated with metal, micropores in the surface of the ultrathin porous polymer film are filledwith metal, metal plating layers at the two sides are communicated, electronic channels are increased, and the internal resistance is effectively reduced, so that when the battery is prepared, a metal tab does not need to be additionally introduced to a tab, it can be guaranteed that electrode slurry does not leak in the subsequent coating process, and production can be better introduced.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a composite current collector, a preparation method thereof, and a lithium battery pole piece. Background technique [0002] Lithium battery pole pieces usually use metal foil as the current collector, among which aluminum foil is used for the positive electrode, and copper foil is used for the negative electrode. For higher energy density, it can be achieved by reducing the weight of the current collector, which requires us to use thinner metal foil or a new type of composite current collector. Limited by the production process, it is difficult to mass-produce copper foil with a thickness of less than 6 microns and aluminum foil with a thickness of less than 8 microns, and the reduction in the thickness of the metal foil will inevitably lead to a decrease in its physical and chemical properties. Another new type of composite current collector, which uses a polymer fil...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/66H01M4/13H01M4/04H01M10/0525
CPCH01M4/667H01M4/13H01M4/0404H01M10/0525Y02E60/10
Inventor 王磊曹勇许涛牛亚如王晓燕任明秀
Owner HEFEI GUOXUAN HIGH TECH POWER ENERGY
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