Safety detection method of lithium battery airtightness

Abstract

The invention relates to a safety detection method of lithium battery airtightness. The method comprises: (1), inert gas is led to a cathode and an anode of a battery group, an inlet valve is closed, and a pressure reduction rate inside the battery group is detected; (2), an inlet and outlet of circulating water of the battery group are sealed, one of inlets and one of outlets of cathode and anode air cavities of the battery group are sealed, inert gas is introduced from the single side of the cathode air cavity or anode air cavity, and a rate of gas leaked from a membrane electrode to another cavity is detected; (3), reactant gas with the equal pressure is led into the anode and cathode of the sealed battery group to activate the battery, the performance of each segment of battery is detected, and performance uniformity of the membrane electrode inside the battery group is determined; (4), the inert gas is used for carrying out equal-pressure pulse blowing on the cathode and the anode of the battery group, residual liquid water in the battery group is blown out, and normal-temperature detection and rising-temperature detection are carried out on the battery group. According to the invention, a membrane electrode with a gas leakage phenomenon can be determined accurately based on inert gas detection, thereby improving the leakage detection efficiency of the membrane electrode.

Description

technical field [0001] The invention relates to the technical field of lithium battery detection, in particular to a safety detection method for the air tightness of lithium batteries. Background technique [0002] Lithium-ion batteries are composed of positive electrodes, negative electrodes, electrolytes, separators and other components. At present, transition metal oxides such as lithium cobalt oxide and lithium nickel cobalt manganese oxide are used for the positive electrode; carbon or graphite and metals are used for the negative electrode; non-aqueous electrolyte is used for the electrolyte; the separator is a porous membrane made of polypropylene and other materials. It is well known that during the charging and discharging process of lithium-ion batteries, the positive and negative electrode materials will react with the electrolyte and generate gas at the same time. When the pressure of the gas reaches a certain level, the battery case will rupture and cause a safe...

AI Technical Summary

Problems solved by technology

It is well known that during the charging and discharging process of lithium-ion batteries, the positive and negative electrode materials will react with the electrolyte and generate gas at the same time. When the pressure of the gas reaches a certain level, the battery case will rupture and cause a safety accident. Manufacture suitable battery cases with a certain compressive strength, but so far, there is no effective, convenient and quick technology to solve this problem