高电压无钴阴极的电解液设计  

Electrolyte Design for High Voltage Cobalt-free Cathodes

作　　者：史利涛 范超君 徐三善 SHI Litao;FAN Chaojun;XU Sanshan(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21期29-31,35,共4页GuangZhou Chemical Industry

摘　　要：尖晶石型镍锰酸锂(LNMO)可以显著提高锂离子电池的能量密度,但开发与之相匹配的电解液是推动LNMO电池应用的的关键。本文采用以氟代溶剂取代传统电解液中的碳酸酯溶剂的方法,显著地提高了电解液的耐氧化能力。测定氟代溶剂对LNMO|石墨电池性能影响的结果表明,使用氟代碳酸乙烯酯(FEC)+甲基三氟乙基碳酸酯(FEMC)的溶剂组合后,可以显著提高电池的性能。以4.85 V为充电截止电压,25℃温度条件下,使用该溶剂电池经过1 240循环后,容量保持率分别从0%提升至78.42;45℃温度下,300次循环后,容量保持率分别从0%提升至78.56%。这些结果表明,全氟代溶剂组合可显著提高镍锰酸锂体系电池性能。Spinel-type LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)(LNMO) can significantly improve the energy density of lithium-ion batteries,but developing a matching electrolyte is the key to promoting the application of LNMO batteries.The oxidation resistance of the electrolyte was significantly improved by replacing the carbonate solvent in the conventional electrolyte with fluorinated solvent.The results of measuring the effect of fluorosubstituted solvents on the performance of LNMO|graphite batteries showed that the performance of the batteries could be significantly improved by using the solvent combination of fluoroethylene carbonate,(FEC)+methyl(2,2,2-trifluoroetyl) carbonate(FEMC).With 4.85 V as the charging cut-off voltage,the capacity retention of the battery with this solvent was improved from 0% to 78.42 after 1 240 cycles at 25 ℃,and from 0% to 78.56% after 300 cycles at 45 ℃,respectively.These results indicated that the combination of perfluorinated solvents could significantly improve the performance of LiNi_(0.5)Mn_(1.5)O_(4) batteries.

关 键 词：锂离子电池 电解液 镍锰酸锂 氟代碳酸乙烯酯 甲基三氟乙基碳酸酯 

分 类 号：TM912[电气工程—电力电子与电力传动]