Jia, HaoYang, ZhijieXu, YaobinGao, PeiyuanZhong, LirongKautz, David J. J.Wu, DengguoFliegler, BenEngelhard, Mark H. H.Matthews, Bethany E. E.Broekhuis, BenjaminCao, XiaFan, JiangWang, ChongminLin, FengXu, Wu2023-04-142023-04-142023-01http://hdl.handle.net/10919/114506It has been widely assumed that the flammability of the liquid electrolyte is one of the most influential factors that determine the safety of lithium-ion batteries (LIBs). Following this consideration, a completely nonflammable electrolyte is designed and adopted for graphite||LiFePO4 (Gr||LFP) batteries. Contrary to the conventional understanding, the completely nonflammable electrolyte with phosphorus-containing solvents exhibits inferior safety performance in commercial Gr||LFP batteries, in comparison to the flammable conventional LiPF6-organocarbonate electrolyte. Mechanistic studies identify the exothermic reactions between the electrolyte (especially the salt LiFSI) and the charged electrodes as the "culprit" behind this counterintuitive phenomenon. The discovery emphasizes the importance of reducing the electrolyte reactivity when designing safe electrolytes, as well as the necessity of evaluating safety performance of electrolytes on a battery level.application/pdfenCreative Commons Attribution 4.0 Internationalelectrolyte reactivitylithium-ion batterieslocalized high concentration electrolytesnonflammabilitysafety performanceArticle - Refereedhttps://doi.org/10.1002/aenm.2022031441614-6840