氟代溶剂2,2-二氟乙基乙酸酯和2,2,2-三氟乙基乙酸酯用于4.85 V LiNi_(0.5)Mn_(1.5)O_(4)|石墨电池  

Use of Fluorinated Solvents 2,2-difluoroethyl Acetate and 2,2,2-Trifluoroacetate Ethyl Ester for 4.85 V LiNi_(0.5)Mn_(1.5)O_(4)|Graphite Batteries

作　　者：徐三善 王安飞 范超君 XU Sanshan;WANG Anfei;FAN Chaojun(Guangzhou Tinci Materials Technology Co.,Ltd.,Guangdong Guangzhou 510760,China)

机构地区：[1]广州天赐高新材料股份有限公司,广东广州510760

出　　处：《广州化工》2024年第20期148-150,168,共4页GuangZhou Chemical Industry

摘　　要：高性能的锂离子电池推进了电动汽车的发展,但传统材料限制了电池能量密度的进一步提升。LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)作为正极材料可显著提高电池的能量密度,并降低成本,但高达4.7 V的电压平台难以匹配当前的电解液体系。因此,开发一种耐高电压的电解液体系是LNMO材料应用的关键。为了改善这个问题,本文分别以耐高电压的2,2-二氟乙基乙酸酯(DFEA)和2,2,2-三氟乙酸乙酯(TFEA)作为替代溶剂,部分替代传统电解液中常用的氟代碳酸甲乙酯(FEMC)溶剂,从而提升了LNMO/石墨锂离子电池的性能。实验结果表明,使用DFEA和TFEA替代FEMC后,电解液的电导率上升,粘度下降。与未替代溶剂电池相比,使用DFEA和TFEA替代电解液的电池在常温下循环的容量保持率分别由45.97%提升到75.45%和68.36%,表明这种溶剂替代策略具有可行性。High performance lithium-ion batteries have promoted the development of electric vehicles,but traditional materials have limited further improvements in battery energy density.LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)as a cathode material can significantly improve the energy density of the battery and reduce the cost of the battery,but the voltage platform of up to 4.7 V is difficult to match the current electrolyte system.Therefore,the development of a high voltage resistant electrolyte system is the key to the application of LNMO materials.To address this issue,high voltage resistant 2,2-difluoroethylacetate(DFEA)and 2,2,2-Trifluoroethyl Acetate(TFEA)were used as alternative solvents,partially replacing the commonly used fluorinated methyl ethyl carbonate(FEMC)solvent in traditional electrolytes,thereby improving the performance of LNMO/graphite lithium-ion batteries.The experimental results showed that the conductivity of the electrolyte increased and the viscosity decreased after using DFEA and TFEA to replace FEMC.At room temperature,compared with unsubstituted solvent batteries,the capacity retention of the batteries with DFEA and TFEA increased from 45.97%to 75.45%and 68.36%,respectively,indicating the feasibility of this solvent substitution strategy.

关 键 词：电解液 LiNi_(0.5)Mn_(1.5)O_(4) 2 2-二氟乙基乙酸酯 2 2 2-三氟乙酸乙酯 溶剂 

分 类 号：TM912[电气工程—电力电子与电力传动]