Multi-tab size-variable high magnification lithium ion battery

Abstract

The invention discloses a multi-tab size-variable high magnification lithium ion battery. The multi-tab size-variable high magnification lithium ion battery mainly comprises a positive pole piece, a negative pole piece, a diaphragm, an electrolyte and a housing. The battery is prepared from pole pieces with different sizes of multiple tabs through winding. A preparation method of the multi-tab lithium ion battery pole piece comprises fully stirring to mix active substances, a conductive agent and a binder according to a certain ratio to obtain slurry, uniformly coating a current collector with the slurry through a coating machine, wherein two sides of the current collector form blank zones, and preparing multiple tabs with different intervals and different widths, wherein the height values of the tabs are determined according to cell thickness and diameters. A winding method replaces a laminated soft package battery preparation process or a process of increasing the number of cylindrical form cell tabs so that a structure is simple, production efficiency is high and a first pass yield is high.

Description

【Technical field】 [0001] The invention relates to the technical field of lithium-ion batteries, in particular to a lithium-ion battery pole piece with variable size of multi-pole ears, a high-rate power lithium-ion battery and a manufacturing method thereof. 【Background technique】 [0002] Lithium-ion battery cells are mainly divided into two manufacturing methods: laminated and wound, and the current popular square batteries basically use a laminated structure, that is, the battery is composed of a positive and negative electrode sheet and a separator. Stacked, and each pole piece must have a tab, too many layers of tabs are difficult to weld, prone to false welding, weak welding or over-welding, and this production method is extremely inefficient, only winding One-fifth of the battery, in addition, during the punching process of the pole piece, there are many side materials, large burrs, thick diaphragm required, and serious powder loss, micro-short circuit and low voltage...

AI Technical Summary

Problems solved by technology

[0002] Lithium-ion battery cells are mainly divided into two manufacturing methods: laminated and wound, and the current popular square batteries basically use a laminated structure, that is, the battery is composed of a positive and negative electrode sheet and a separator. Stacked, and each pole piece must have a tab, too many layers of tabs are difficult to weld, prone to false welding, weak welding or over-welding, and this production method is extremely inefficient, only winding One-fifth of the battery, in addition, during the punching process of the pole piece, there are many side materials, large burrs, thick diaphragm required, and serious powder loss, micro-short circuit and low voltage phenomenon are common, the production cost is high, and the pass rate of the process is low. And there is a big hidden danger to the safety performance of the battery; while the popular cylindrical battery on the market generally adopts a winding structure, because the structure is simple, the production efficiency is high, the electrode burrs are small and less, and the diaphragm does not need to be too thick, so it is popular. However, due to the length of the pole piece, there are generally only 1-3 tabs on a single pole piece. Intermittent coating is used, and then the tabs are welded, resulting in increased process and time-consuming increase, and lithium is easily separated at the welding of the negative electrode tab, which is safe. Hidden dangers, and because the internal resistance is relatively large due to the small number of tabs, it is not conducive to high-current charging and discharging, and the specific power cannot be fully utilized

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