Liquid injection process for core of lithium ionic cell

Abstract

The invention relates to a liquid injection process of an electric core of a lithium-ion battery, the liquid injection process comprises: (S1) when in liquid injection of the electric core of the lithium-ion battery, 70-90 percent of the total amount of pre-determined electrolyte is firstly injected for being placed for 14-20 hours; (S2) the pre-charging is carried out on the electric core, the charging condition is that the charging is carried out for 210-1200 minutes at 0.06-0.2C; (S3) the residual electrolyte is injected in the electric core after the completion of the pre-charging under the vacuum pumping condition, and the sealing is carried out for the preparation. The process can improve the performance of the electric core, improve the gram capacity exertion of positive electrode material and improve the capacity of the electric core and the cycle retention rate of a platform; the electrolyte is saved, the production cost of the electric core is reduced, the environmental air is improved, and the service life of a device is prolonged.

Description

【Technical field】 [0001] The invention relates to the field of lithium ion batteries, in particular to a liquid injection process for lithium ion battery cells. 【Background technique】 [0002] When the lithium-ion battery cell is pre-charged with a small current, a dense solid electrolyte interphase film (Solid electrolyte interphase, SEI for short) will be formed on the surface of the electrode particles. During the chemical reaction process of forming SEI, gas is generated, and some gas cannot be discharged between the electrodes, causing adverse effects on the performance of the battery cell; at the same time, the discharged gas will bring out more electrolyte, resulting in waste of electrolyte , equipment corrosion and environmental pollution. [0003] During the processing of lithium-ion battery cells, a one-time liquid injection process is generally used to completely inject a sufficient amount of electrolyte at one time. During the liquid injection process, the liqu...

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Problems solved by technology

In this case, when the pole piece of the cell is fully wetted and the opening is formed, due to the reaction between the pole piece and the electrolyte to form an SEI film, a certain amount of gas is generated, and the gas and the shell wall, pole piece, and diaphragm exist on the surface. Tension, when the air pressure difference inside and outside the shell is small, part of the gas still stays in the cell, causing adverse effects on the performance of the cell; at the same time, the discharged gas will bring out a part of the electrolyte, which wastes the electrolyte on the one hand , corrode the equipment, on the other hand, the volatilization produced by the overflowing electrolyte will cause great pollution to the environment

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