Multifunctional solvent molecule design enables high-voltage Li-ion batteries

作者：Junbo Zhang, Haikuo Zhang, Suting Weng, Ruhong Li, Di Lu, Tao Deng, Shuo‐Qing Zhang, Ling Lv, Jiacheng Qi, Xuezhang Xiao, Li‐Wu Fan, Shujiang Geng, Fuhui Wang, Lixin Chen, Malachi Noked, Xuefeng Wang, Xiulin Fan · 发表于：Nature Communications · 年份：2023 · 被引用次数：192 · 研究领域：Advancements in Battery Materials、Advanced Battery Materials and Technologies、Advanced Battery Technologies Research

Abstract Elevating the charging cut-off voltage is one of the efficient approaches to boost the energy density of Li-ion batteries (LIBs). However, this method is limited by the occurrence of severe parasitic reactions at the electrolyte/electrode interfaces. Herein, to address this issue, we design a non-flammable fluorinated sulfonate electrolyte by multifunctional solvent molecule design, which enables the formation of an inorganic-rich cathode electrolyte interphase (CEI) on high-voltage cathodes and a hybrid organic/inorganic solid electrolyte interphase (SEI) on the graphite anode. The electrolyte, consisting of 1.9 M LiFSI in a 1:2 v / v mixture of 2,2,2-trifluoroethyl trifluoromethanesulfonate and 2,2,2-trifluoroethyl methanesulfonate, endows 4.55 V-charged graphite||LiCoO 2 and 4.6 V-charged graphite||NCM811 batteries with capacity retentions of 89% over 5329 cycles and 85% over 2002 cycles, respectively, thus resulting in energy density increases of 33% and 16% compared to those charged to 4.3 V. This work demonstrates a practical strategy for upgrading the commercial LIBs.