Lithium battery thick pole piece rolling method, pole piece rolling device and lithium battery

A lithium battery and roll pressing technology, which is applied in electrode rolling/calendering, electrode collector coating, electrode manufacturing, etc., can solve the problem of difficult to achieve large-scale processing and mass production, and the difficulty of high-pressure compaction for thick electrodes, improving Without problems such as energy density, it can achieve the effect of increasing dependence, realizing large-scale processing and mass production, and low cost

Pending Publication Date: 2020-10-30
江西安驰新能源科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to: address the deficiencies of the prior art, such as: adding surfactants, porous active substances and other substances makes the cost high; it is difficult to achieve high-pressure compaction for thick electrode

Method used

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  • Lithium battery thick pole piece rolling method, pole piece rolling device and lithium battery
  • Lithium battery thick pole piece rolling method, pole piece rolling device and lithium battery
  • Lithium battery thick pole piece rolling method, pole piece rolling device and lithium battery

Examples

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Example Embodiment

[0020] Example 1

[0021] Thick positive electrode preparation: dry mix the positive active material lithium iron phosphate 96.8%, conductive agent SP0.5%, emulsion polymerization binder PVDF 0.85% and suspension polymerization binder PVDF 0.85%, and then add the dispersion 0.5% carbon nanotube and graphene mixed conductive agent 1.0%, and the solvent is mixed and stirred evenly. The diameter of the carbon nanotubes is 5nm and the viscosity reaches 5000-8000mPa·s. The positive electrode slurry is prepared, and the positive electrode slurry is coated on the coating. On the carbon aluminum foil, a positive electrode sheet with a thickness of 300 μm is obtained after drying, and the pole piece rolling device of the present invention is used for secondary rolling, wherein the first roll compaction density is 2.0g / cc, and the second roll compaction The density is 2.55g / cc, and then die-cutting to obtain a thick positive plate;

[0022] Thick negative electrode sheet preparation: dry bl...

Example Embodiment

[0024] Example 2

[0025] Thick positive electrode preparation: dry mix the positive electrode active material lithium iron phosphate 96.8%, conductive agent SP 0.6%, emulsion polymerization binder PVDF 0.8% and suspension polymerization binder PVDF 0.8%, and then add the dispersion 0.5% of carbon nanotubes and graphene as conductive agent, 1.0% of conductive agent mixed with carbon nanotubes and graphene, and the solvent is mixed and stirred evenly. The diameter of carbon nanotubes is 5nm, and the viscosity reaches 5000-8000mPa·s. On the carbon aluminum foil, a positive electrode sheet with a thickness of 300 μm is obtained after drying. The pole piece rolling device of the present invention is used for secondary rolling, wherein the first roll compaction density is 2.1g / cc, and the second roll compaction The density is 2.57g / cc, and then die-cutting to obtain a thick positive electrode;

[0026] Preparation of thick negative electrode sheet: dry mix amorphous carbon coated graph...

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Abstract

The invention discloses a lithium battery thick pole piece rolling method, a pole piece rolling device and a lithium battery. Positive pole slurry and negative pole slurry are coated on a carbon-coated aluminum foil and a copper foil to obtain a positive pole piece and a negative pole piece respectively. Primary rolling and secondary rolling are carried out on the pole pieces sequentially to obtain thick pole pieces with a certain compaction density. Die cutting is carried out on the thick pole pieces to obtain a corresponding thick positive pole piece and a corresponding thick negative pole piece, and winding, assembling, baking, liquid injection, formation and capacity grading are carried out on the thick positive pole piece and the thick negative pole piece and a diaphragm to obtain thelithium battery. Circular concave points are uniformly distributed in the surface of a roller shaft of the rolling device, and concave points are uniformly distributed on the surface of a rolled thick pole piece, so that the specific surface area of the pole piece is increased, and the wettability of electrolyte during battery electrolyte injection is improved. After the battery is disassembled,the surface of the pole piece is free of wrinkles and smooth in interface, so that powder falling of the pole piece can be reduced, a current collector is not easy to scratch a diaphragm to cause short circuit of the battery, the attachment of active substances and the current collector can be increased, the active substances cannot fall off from the current collector, and the capacity and the safety performance of a battery cell can be improved.

Description

technical field [0001] The invention relates to the technical field of battery technology, in particular to a lithium battery thick pole piece rolling method, a pole piece rolling device and the lithium battery. Background technique [0002] Improving energy density and reducing cost are the goals of the lithium-ion battery industry. Increasing the active material loading of the pole piece can not only increase the energy density, but also reduce the amount of positive and negative current collectors and separators to achieve the purpose of reducing costs; but thick pole pieces It also brings a series of problems, the battery polarization is large, the battery pole piece is thicker, the path of lithium ion diffusion increases, the thickness direction of the pole piece will produce a large lithium ion concentration gradient, and the compaction density of the pole piece increases, the pores It becomes smaller, and the path of lithium ion movement in the thickness direction of ...

Claims

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Application Information

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IPC IPC(8): H01M4/04H01M10/0525
CPCH01M4/0404H01M4/0435H01M10/0525Y02E60/10
Inventor 汪正兵徐小明白科谢爱亮孙玉龙宋庆彬周焘陈富源
Owner 江西安驰新能源科技有限公司
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