Safety relief valve of lithium battery cover body and manufacturing method of same

Abstract

The invention relates to a safety relief valve of a lithium battery cover body and a manufacturing method of the same. The manufacturing method for the safety relief valve of the lithium battery cover body comprises the following steps of: arranging an annular groove (explosive groove) in the lithium battery cover body, wherein the lithium battery cover body is made of aluminum alloy; heating the inner part of the annular groove to enable the temperature of the inner part of the annular groove to reach 200-500 DEG C; and cooling the annular groove to form the safety relief valve on the lithium battery cover body. As the aluminum alloy is heated to a proper temperature, the internal stress of the safety relief valve can be eliminated, the hardness of materials is reduced, uniform strength of the materials is realized, brittle ruptures caused by processing and hardening are reduced, and therefore, the purpose of increasing yield is achieved.

Description

technical field [0001] The invention relates to a method for manufacturing a pressure relief safety valve for a lithium battery cover. Background technique [0002] Due to the advantages of large capacity, high energy density, high power density, stable discharge, no memory effect, and long storage life, lithium batteries are widely used in daily life and various industries, especially for electronic products that are light, thin, and short (such as mobile phones, PDAs, notebook computers, etc.), it is more suitable to use lithium batteries as power sources. [0003] However, if the charging and discharging operation is performed under abnormal conditions, a large amount of gas will be generated in the battery due to rapid evaporation of the electrolyte or side reactions, which will increase the internal pressure of the battery and cause accidents such as explosion or fire. At present, the lid body of the lithium battery is processed to form a pressure relief safety valve, ...

AI Technical Summary

Problems solved by technology

However, this punching method must accurately control the thickness between the bottom (222) of the annular groove (221) and the bottom (211) of the cover body and make it very thin (0.02 millimeters (mm) to 0.03mm), to ensure that the safety valve is at 15-25kg / cm 2 If the thickness is too thick, the valve cannot be opened to release the pressure, causing damage to the battery module. If the punching depth is too deep, the lithium battery cover will be easily damaged, resulting in a drop in yield, or the battery has not been used abnormally. I had doubts about exploding before

[0005] In view of the fact that the existing method for manufacturing the pressure relief safety valve of the lithium battery cover is not easy to control the thickness between the bottom of the annular groove and the bottom of the cover, which affects the normal use of the pressure relief safety valve, after a long period of After extensive research and repeated tests, the manufacturing method of the pressure relief safety valve for the lithium battery cover was finally invented

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