关键词: 锂离子电池, 内部短路, 失效机理, 挤压

Abstract: In this work,the battery impact testing machine has been used to study the failure progress of internal short-circuit ( ISC) for lithium ion batteries. The reaction mechanisms between cathode/anode and electrolyte in the battery at different temperatures were characterized by differential scanning calorimetry ( DSC) ,gas chromatography/mass spectrometry ( GC/MS) and X-ray diffraction ( XRD) . The experimental results show that the ISC failure of the battery was mainly due to the reaction between cathode Li0.5CoO2 and electrolyte. The decomposition and oxygen evolution reactions of cathode occurred when the temperature reached a certain value. At the same time a fierce oxidation reaction occurred between oxygen and electrolyte,giving out a large quantity of CO2 gas,and breaking aluminum can,thus causing the battery exploded. And the decomposition of SEI film and the initial reaction between anode and electrolyte were mainly to accumulating heat for the reaction between cathode and electrolyte.

Key words: lithium ion battery, internal short-circuit, failure mechanism, impact