Abstract
Electrolyte design is essential for stabilizing lithium metal anodes and localized high-concentration elec-trolyte(LHCE)is a promising one.However,the state-of-the-art LHCE remains insufficient to ensure long-cycling lithium metal anodes.Herein,regulating the solvation structure of lithium ions in LHCE by weakening the solvating power of diluents is proposed for improving LHCE performance.A diluent,1,1,2,2,3,3,4,4-octafluoro-5-(1,1,2,2-tetrafluoroethoxy)pentane(OFE),with weaker solvating power is in-troduced to increase the proportion of aggregates(an anion interacts with more than two lithium ions,AGG-n)in electrolyte compared with the commonly used 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether(TTE).The decomposition of AGG-n in OFE-based LHCE intensifies the formation of anion-derived solid electrolyte interphase and improves the uniformity of lithium deposition.Lithium metal batteries with OFE-based LHCE deliver a superior lifespan of 190 cycles compared with 90 cycles of TTE-based LHCE under demanding conditions.Furthermore,a pouch cell with OFE-based LHCE delivers a specific en-ergy of 417Wh/kg and undergoes 49 cycles.This work provides guidance for designing high-performance electrolytes for lithium metal batteries.
基金项目
National Key Research and De-velopment Program(2021YFB2500300)
National Key Research and De-velopment Program(2021YFB2400300)
北京市自然科学基金(JQ20004)
河北省科技计划(22344402D)
国家自然科学基金(22209010)
国家自然科学基金(22109007)
中国博士后科学基金(2021M700404)
Beijing Institute of Technology Research Fund Program for Young Scholars()
NETL
NSTL
万方数据