A Diagnostic Method of Internal Short Circuit Fault in Lithium-ion Battery

The internal short circuit (ISC) fault endangers the safety of lithium-ion batteries, and it is a major trigger of thermal runaway. Therefore, the ISC fault early detecting is significant to improve the safety of battery system. This paper proposes a method to diagnose the ISC fault based on the variation of open circuit voltage (OCV) values. An equivalent circuit model is used to study the ISC. The equivalent ISC resistance is derived by extracting characteristics of OCV, then the ISC fault is diagnosed. To verify the accuracy of the proposed method, experiments were carried out. The results show that the average error of the estimated equivalent ISC resistance is less than 10% in the range of 60 ~100% SOC, which indicates that the proposed method can effectively detect ISC fault in the battery.