Battery leakage detection method

The invention provides a battery leakage detection method. The method includes following steps: step 1, injecting electrolyte and a tracer agent into a battery, and completing encapsulation of the battery; step 2, putting the battery obtained in the S1 into a closed container with a mass spectrometer, vacuumizing the container, holding pressure, filling gas, and repeating in this way; step 3, starting the mass spectrometer, detecting gas extracted from the closed container, and judging whether the battery leaks or not according to whether the tracer agent is present or not, wherein the traceragent is a substance containing at least one of elements 15N, 13C, 14C, 17O, 18O, 2H and 3H, does not corrode pole pieces, current collectors, pole lugs and an encapsulation material and does not react with the electrolyte or is not in negative reaction affecting performance of the electrolyte. By the method, defective batteries can be screened out conveniently and quickly to avoid potential safety hazards caused by the f