Lithium ion battery liquid injection method

Abstract

The invention provides a lithium ion battery liquid injection method, which comprises the following steps: 1) cooling a baked electrical core with qualified water content, then transferring the electrical core with temperature dropped to 35-75 DEG C into a glove box, inserting a retainer cup into a corresponding steel shell of the electrical core, and injecting a liquid; 2) putting the electrical core injected with the liquid in the step 1) into an oven with the temperature set at 40-75 DEG C; 3) vacuumizing the oven until the oven pressure is-0.075 to-0.095MPa, putting the electrical core into the oven with the pressure of-0.075 to-0.095MPa for standing for 2-20s; 4) filling the oven in the vacuum state in the step 3) with nitrogen until the oven pressure is 0-0.1MPa, and placing the electrical core in the oven with the pressure of 0-0.1MPa for pressure maintaining for 60-300s; 5) vacuumizing the oven in the nitrogen atmosphere in the step 4) until the oven pressure is-0.075 to-0.095MPa, putting the electrical core into the oven with the pressure of-0.075 to-0.095MPa for standing for 2-20s; and 6) filling the oven in the vacuum state in the step 5) with the nitrogen until the oven pressure is 0-0.1MPa, and placing the electrical core in the oven with the pressure of 0-0.1MPa for pressure maintaining for 60-300s.

Description

[0001] 【Technical field】 [0002] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a liquid injection method for lithium ion batteries. [0003] 【Background technique】 [0004] Liquid injection is an important process in the production process of lithium-ion batteries. Since the lithium salt in the electrolyte can react with a small amount of water, the battery needs to be baked to remove the moisture in the battery cell before liquid injection. The liquid injection process needs to be sealed It is carried out in a low dew point environment, and at the same time, it is ensured that the liquid injection can be completed in a short time, so as to prevent the electric core from absorbing water and causing the electrical performance to deteriorate. [0005] At present, the liquid injection process of cylindrical lithium-ion batteries generally adopts the method of first injecting liquid and then vacuuming. First, the electrolyte is...

AI Technical Summary

Problems solved by technology

Since the electrolyte uses an organic solvent, its fluidity is poor at room temperature, and it is difficult to completely infiltrate the electrode in a short period of time. Therefore, the electrolyte infiltration process takes a long time, resulting in low production efficiency and deterioration of the water absorption performance of the cell.

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