Lithium ion battery electrolyte injection method

Abstract

The invention relates to a lithium ion battery electrolyte injection method, and belongs to the technical field of lithium ion batteries. According to the technical scheme, the lithium ion battery electrolyte injection method comprises the following steps of putting a lithium ion battery cell into a vacuum system to be vacuumized to the vacuum degree of minus 0.1 to minus 0.08 Mpa, then injectingan electrolyte solvent into a lithium ion battery dry cell which is kept vacuum to stand, after the vacuum state is broken, inflating inert gas to be pressurized, keeping positive pressure inside thecell at 0.5-1.0 Mpa, and after depressurizing, conducting vacuumizing again to the vacuum degree of minus 0.1 to minus 0.08 Mpa; finally, injecting electrolyte added with lithium salt and additive inthe cell, conducting vacuumizing to the vacuum degree of minus 0.08 to minus 0.06 Mpa, after the vacuum state is broken, inflating inertia gas to be pressurized and keeping positive pressure inside the cell at 0.5-1.0 Mpa; after depressurizing, checking whether the electrolyte is left on the upper surface of the battery cell or not to supplement the electrolyte. The lithium ion battery electrolyteinjection method improves the wettability of the battery and the electrolyte injection efficiency of the battery.

Description

Technical field [0001] The invention relates to a lithium ion battery liquid injection method, which belongs to the technical field of lithium ion batteries. Background technique [0002] Because lithium-ion batteries have the advantages of high energy density, long cycle life, safety and environmental protection, they are widely used in energy storage and power fields. With the expansion of the application range and the maturity of lithium-ion technology, people have put forward more ideas on the performance of lithium-ion batteries. High demand, especially electric vehicle batteries require higher energy density to increase the range of electric vehicles, and the demand for high energy density lithium-ion batteries is increasing. As the energy density of lithium-ion batteries increases, the internal material density of the battery increases, and the problems of slow liquid absorption and insufficient liquid absorption appear. Aprotic solvents have poor wettability for positive...

AI Technical Summary

Problems solved by technology

Due to the increase in the energy density of lithium-ion batteries, the density of materials inside the battery increases, and the problems of slow liquid absorption and insufficient liquid absorption appear. Aprotic solvents have poor wettability to positive and negative active materials with high specific surface areas, resulting in poor battery materials. The contact resistance with the electrolyte increases, and the internal resistance of the battery increases. Insufficient liquid injection will seriously affect the electrical performance of the battery. The extension of liquid injection time and standing time will seriously affect production efficiency.

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