储能科学与技术2024，Vol.13Issue(7)：2161-2170,10.DOI:10.19799/j.cnki.2095-4239.2024.0117
乙基膦酸二乙酯基阻燃宽温域电解液在锂离子电池中的应用
Diethyl ethylphosphonate-based flame-retardant wide-temperature-range electrolyte in lithium-ion batteries
摘要
Abstract
Lithium-ion batteries are extensively used in various applications such as electric vehicles and electrochemical energy storage systems.However,safety concerns related to flammability and low flash point of commercial carbonate electrolytes limit their broad application.The incorporation of nonflammable flame-retardant diethyl ethylphosphonate(DEEP)into carbonate electrolytes has been shown to effectively reduce the risk of battery fires and explosions by mitigating electrolyte combustion.Nonetheless,the strong interaction between DEEP and Li+leads to the infiltration of DEEP into the first solvated shell layer of Li+,contributing to the formation of solid electrolyte interphase(SEI)on the graphite anode.The SEI formed through the reductive decomposition of DEEP provides inadequate electron shielding,failing to halt the ongoing decomposition at the interface and leading to the failure of graphite anodes in DEEP-modified carbonate electrolytes.To address this issue,this study adopts a synergistic strategy,using ethylene carbonate as a strong ligand solvent and linear carbonate as a weak ligand solvent.This approach aims to diminish the interaction strength between DEEP and Li+,decrease the proportion of DEEP in the first solvated shell layer of Li+,and reduce the decomposition of DEEP on the anode.In the developed DEEP-modified carbonate electrolyte with a conventional concentration(～1.15 mol/L),the graphite anode shows an impressive capacity retention of 95.6%after 150 cycles.In addition,the electrolyte remains fluid at-60℃,and the graphite/LiFePO4 battery retains 49.3%of its capacity after 50 cycles at-20℃.关键词
锂离子电池/磷酸酯/石墨电极/不可燃电解液/低温性能Key words
lithium-ion battery/phosphate/graphite electrode/non-flammable electrolyte/low temperature performance分类
信息技术与安全科学引用本文复制引用
汪书苹,杨献坤,李昌豪,曾子琪,程宜风,谢佳..乙基膦酸二乙酯基阻燃宽温域电解液在锂离子电池中的应用[J].储能科学与技术,2024,13(7):2161-2170,10.基金项目
国网安徽省电力有限公司科技项目(B31205230027). （B31205230027）
