Leak detection method before liquid injection and sealing of lithium ion storage battery

Abstract

The invention relates to a method for detecting the leak of a lithium ion storage battery before liquid injection and sealing. The method comprises the following steps that: one end of a connecting cavity is connected to a quickly-locking flange of a helium mass-spectrometer leak detector, and the other end of the connecting cavity is connected to a liquid injection opening of the battery in a sealing manner before the liquid injection and the sealing; and the helium mass-spectrometer leak detector vacuums the inside of the battery through the liquid injection opening of the battery to detect large leak and small leak of the battery until the battery is completely positioned in a qualified sealing state. In the method, the helium mass-spectrometer leak detector vacuums the inside of the battery before the liquid injection and the sealing of the battery, so that the large leak can be detected; when the large leak of the battery occurs, only the shell is replaced, and a battery cell part with high cost can be continuously used, so that the manufacturing cost of the battery is reduced; a welding part outside the battery is aligned by a helium spray gun for point leak detection; leak rate data automatically occurs on the helium mass-spectrometer leak detector, so that whether the small leak exists at a detected position of the battery is easy to detect; and the small leak is subjected to secondary welding through a laser welding machine, so that the reliability of the battery is improved, and the waste caused by discarded batteries is reduced.

Description

technical field [0001] The invention belongs to the technical field of non-destructive leak detection for lithium ion storage battery sealing test, and in particular relates to a leak detection method for lithium ion storage battery before liquid injection and sealing. Background technique [0002] Due to its high working voltage, small size, light weight, high energy, no memory effect, no pollution, small self-discharge, and long cycle life, lithium-ion batteries are ideal energy sources for development in the 21st century. During the preparation process of lithium-ion batteries, the airtightness of the batteries is an important indicator to determine whether the batteries are qualified. Therefore, it is one of the indispensable processes in the preparation process of lithium-ion batteries to conduct a leak test on the batteries. [0003] At present, the leak detection method of back pressure is usually used for leak detection of lithium-ion batteries. The performance test...

AI Technical Summary

Problems solved by technology

This method can better judge whether there is leakage in the battery, but it cannot judge the specific part of the battery leakage. There is no remedy for the leaking battery found, and it can only be discarded, resulting in a lot of waste.

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