High-capacity soft-package lithium battery liquid injection method

Abstract

The invention relates to the field of lithium battery production, in particular to a high-capacity soft-package lithium battery liquid injection method. The method comprises the following steps: taking a high-capacity soft-package lithium battery, feeding the high-capacity soft-package lithium battery to a weighing station for weighing, and transferring the high-capacity soft-package lithium battery into a liquid injection cavity for liquid injection by enabling an air bag opening of the high-capacity soft-package lithium battery to face upwards; enabling the liquid injection mode of the high-capacity soft package lithium battery to be vertical or inclined, and supporting the lithium battery by a clamp; after liquid injection is completed, transferring the high-capacity soft package lithium battery to a vacuum standing station, and carrying out gradient vacuumizing and packaging; and after packaging is completed, transferring the high-capacity soft package lithium battery to a discharging weighing station so as to be weighed after liquid injection. The high-capacity soft-package lithium battery liquid injection method has the beneficial effects that the diffusion and absorption efficiency of the electrolyte in the lithium battery is high, the infiltration is uniform, the absorption efficiency of the electrolyte is greatly improved, and the standing time after liquid injection is effectively shortened.

Description

technical field [0001] The invention relates to the field of lithium battery production, in particular to a liquid injection method for a high-capacity soft-pack lithium battery. Background technique [0002] With the rapid development of lithium-ion batteries and increasingly fierce competition in the industry, reducing battery costs has become the general trend. Improving production efficiency and reducing system energy consumption have become one of the effective means of reducing battery costs. Due to the large size of the high-capacity pouch battery and the large amount of electrolyte required, most of the electrolyte will gather at the bottom of the battery during liquid injection, resulting in slow electrolyte absorption efficiency, uneven distribution of electrolyte, and long standing time after liquid injection. It even causes problems such as insufficient battery liquid retention, serious polarization, and decreased cycle performance. At present, the liquid inject...

AI Technical Summary

Problems solved by technology

Due to the large size of the high-capacity pouch battery and the large amount of electrolyte required, most of the electrolyte will gather at the bottom of the battery during liquid injection, resulting in slow electrolyte absorption efficiency, uneven distribution of electrolyte, and long standing time after liquid injection. It may even cause problems such as insufficient battery liquid retention, serious polarization, and decreased cycle performance.

At present, the liquid injection in the industry mostly adopts heating, circulating vacuum, prolonging the standing time after liquid injection, etc. to promote the diffusion and absorption of the electrolyte. 35°C improves the battery liquid absorption and production efficiency; the Chinese invention patent with the publication number CN112490599A injects liquid into the lithium battery by means of multi-step gradient cycle pressurization to improve the electrolyte infiltration effect and production efficiency, etc., but such The method system consumes a lot of energy and the program is complicated

On the other hand, the existing liquid injection cavity is mostly placed vertically when the battery is injected, and the large battery is easily deformed after vacuuming due to its own gravity and the characteristics of the soft package.

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