Collision-Caused thermal runaway investigation of li-ion battery in Real-World electric vehicles

Abstract

Due to the limitations of static and non-realistic load conditions in laboratory environments, existing battery thermal runaway mechanism/characterization studies are unable to realistically restore the operating conditions and extract thermal runaway characteristics. In this paper, the actual thermal runaway historical data of collision electric vehicles are used. In-depth data mining and characterization of historical data from different perspectives are performed for the three months before the accident. Several feature parameters and outliers are extracted in the paper to explore the characteristics and mechanisms of thermal runaway due to collisions in the real world. In addition, based on the anomaly fluctuation analysis, a modified overall Shannon entropy is proposed to infer the exact collision time and location. The results show that the diagnostic results match the thermal runaway location in the accident report. In this paper, we used actual data to count the anomalous information before the occurrence of thermal runaway, and utilized the corresponding evaluation indexes to diagnose the anomalous features in the early stage of the accident 91 days in advance. This is the first study of thermal runaway of batteries caused by collision based on actual accident cases and real vehicle operation data.