丁二酸酐在锂离子电池电解液中的应用

在锂离子电池电解液1 mol/L六氟磷酸锂/碳酸乙烯酯+碳酸二甲酯+碳酸甲乙酯（体积比为1∶1∶1）溶液中添加丁二酸酐作为提高电池充放电效率的添加剂。 采用恒流充放电测试、循环伏安曲线、线性伏安曲线和电化学阻抗谱等手段，研究了添加剂丁二酸酐对电解液电化学稳定窗口的影响，以及丁二酸酐与锰酸锂材料的相容性。结果表明：在电解液中添加2%（质量分数）的丁二酸酐，提高了LiMn2O4/Li电池常温和高温容量保持率。丁二酸酐可以优先于基础电解液发生少量氧化分解，从而降低了LiMn2O4/Li电池的极化。同时，丁二酸酐也可降低电池循环过程的阻抗。

Application of succinic anhydride as electrolyte additive in lithium-ion batteries

Succinic anhydride（SA） was selected as an additive to improve the charge-discharge efficiency in lithium-ion bat-teries.The base electrolyte is 1 mol/L LiPF6/［ethylene carbonate（EC）+diethyl carbonate（DMC）+ethyl-methyl carbonate（EMC）］（volume ratio of 1∶1∶1）.Constant current charge-discharge test，cyclic voltammeter curves，linear sweep voltammetry （LSV），and electrochemical impedance spectra（EIS） were used to investigate the influence of SA on electrochemical stabi-lity window of electrolytes as well as the compatibility of SA with LiMn2O4 electrode.Results showed the capacity of LiMn2O4/Li cell using electrolyte with 2%（mass fraction） SA was increased，whether it was at room temperature or high temperature. The electrolyte with SA had a lower oxidative stability than base electrolyte and thus decomposed first and reduced the pola-rization of LiMn2O4/Li cell.Meanwhile，SA could also reduce the impedance of the cells in the cycles.