文献类型：期刊文献

英文题名：Thermal safety evolution of lithium-ion batteries under high-temperature float charge: implications of swelling and aging

作者：Wang, Meng[1];Wu, Senming[1];Chen, Ying[1];Luan, Weiling[1];Chen, Haofeng[1]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Key Lab Adv Battery Syst & Safety CPCIF, Shanghai 200237, Peoples R China

年份：2026

卷号：282

外文期刊名：APPLIED THERMAL ENGINEERING

收录：;EI(收录号：20254519468631);WOS:【SCI-EXPANDED(收录号:WOS:001616149100014)】；

基金：The authors gratefully acknowledge the support from the National Natural Science Foundation of China (52375144, 52375145 and 52205153) , Shanghai Pujiang Programme (23PJD019) , the East China University of Science and Technology during the course of this work.

语种：英文

外文关键词：Lithium-ion batteries; High-temperature aging; Float charge; Swollen; Thermal safety

摘要：The safety of lithium-ion batteries (LIBs) during operation has attracted widespread attention, particularly under high-temperature float charge (HTFC) conditions. Previous studies have mainly focused on capacity fade and gas evolution during HTFC aging, while the impact on battery thermal safety remains poorly understood. In this work, the evolution mechanisms of thermal safety of LIBs under HTFC conditions were systematically investigated by combining electrochemical performance, morphological, structural, gas evolution, and thermal analyses. A novel finding of this study is the identification of a critical temperature threshold (similar to 135 degrees C) that separates two opposite thermal stability patterns. Below this threshold, thermal stability increases with decreasing state of health (SOH), primarily due to decomposition and regeneration of the solid electrolyte interphase (SEI). Above the threshold, thermal stability decreases with decreasing SOH because of separator aging and cathode degradation, which substantially raise the risk of internal short circuits and thermal runaway (TR). Moreover, gas analysis reveals that the gases generated during HTFC aging (mainly CO2 and light hydrocarbons) are of low flammability and impose limited explosion risk; instead, they accelerate capacity degradation with minimal direct impact on thermal safety. Overall, this work fills a critical gap by demonstrating that swelling of LIBs under HTFC conditions cannot be universally classified as hazardous; instead, their thermal stability must be evaluated across distinct temperature ranges, providing a new perspective for safety assessment of LIBs under complex service conditions.