Lithium powder lithium-supplementing device for negative pole piece

Abstract

The invention provides a lithium powder lithium-supplementing device for a negative pole piece. The device comprises an electrostatic lithium-supplementing mechanism, wherein the electrostatic lithium-supplementing mechanism comprises an electrostatic generation assembly, multiple injection needle tubes, a slurry pump, an electrostatic collection roller and a lithium powder slurry supply assembly,the electrostatic collection roller and an injection assembly are arranged oppositely and located at the two sides of the conveying direction of the pole piece respectively, the electrostatic collection roller is grounded, the electrostatic generation assembly is used for negatively charging lithium powder injected to the pole piece form the injection needle tubes, the injection assembly comprises the multiple injection needle tubes, the multiple injection needle tubes are arranged at intervals in the width direction of the pole piece and all vertically point to the pole piece, the lithium powder slurry supply assembly and the slurry pump communicate through a pipeline, and the slurry pump communicates with the multiple injection needle tubes through pipelines respectively. According to the device, the pole piece can be pre-lithiated through cooperation of the electrostatic generation assembly, the electrostatic collection roller and the injection assembly, and the quantity of the injection needle tubes is adjusted according to the actual width of the pole piece, so that pre-lithiation is more uniform.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a negative pole piece lithium powder lithium replenishment device. Background technique [0002] At present, lithium-ion secondary batteries are widely used in the market due to their high energy density and cycle times. When used as a power battery, energy density is an important performance requirement that people pursue. At present, the use of high-nickel ternary cathode materials and silicon anode materials is an important development direction for lithium-ion battery developers to improve battery energy density. Compared with the graphite negative electrode material, the silicon negative electrode material consumes a large amount of lithium ions to form the SEI film during the first charge of the battery, which is equivalent to the content of lithium ions in the positive electrode material consumed, thereby reducing the capacity of the battery. Therefore, supplem...

AI Technical Summary

Problems solved by technology

However, in industrial applications, direct use of lithium powder is prone to flying, which is very easy to cause safety problems

Therefore, it is necessary to use specific methods and equipment to supplement lithium. For example, the patent of application number 201210237240.4 discloses a method for directly depositing lithium powder in an electric field to supplement lithium on the negative electrode sheet. Although this method can complete lithium supplementation, the lithium powder inlet Only one uniformity in the electric field environment is very difficult, the deposition of lithium powder takes a long time to reach the negative plate, the efficiency is poor, and the floating lithium powder is more prone to the risk of fire and explosion

[0004] Another example is the patent application number 201811193753.3, which discloses a separator for silicon carbon negative electrode lithium supplementation. The separator is composed of metal lithium powder, binder and lithium-ion battery separator. Although the battery efficiency is improved for the first time after using the separator, the The thickness of the separator is usually very thin, and the lithium powder is easy to penetrate the separator when it is directly deposited on the separator. There is a risk of battery short circuit, and the excess lithium powder in the edge area cannot be fully utilized.

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