利用氟代碳酸乙烯酯(FEC)和二氟草酸硼酸锂(LiDFOB)优良的成膜性、稳定性和耐高压性，研究了在1 mol/L LiPF6 FEC/碳酸丙烯酯(PC)/碳酸二甲酯(DMC)中加入LiDFOB和三(三甲基硅烷)硼酸酯(TMSB)对高电压材料LiNi0.5Mn1.5O4电化学性能的影响，利用循环伏安法和扫描电镜分析了两种电解液中电化学性能的差异. 结果表明，在FEC基电解液中加入LiDFOB和添加剂TMSB使电解液的分解电位提高至5.5 V(vs. Li/Li+)以上，对铝箔有良好的钝化作用. Li/LiNi0.5Mn1.5O4半电池在含LiDFOB和TMSB的电解液中的初始放电比容量达126.8 mA?h/g，库伦效率为99%，充放电200次后比容量仍为108.2 mA?h/g，容量保持率为85.3%. 而在不含LiDFOB和TMSB的电解液中，电池容量迅速衰减，85次充放电循环后容量保持率仅为60.7%.
Fluoroethylene carbonate (FEC) and lithium oxalyldifluoroborate (LiDFOB) were regarded as the excellent solvent and additive for high voltage lithium-ion battery electrolyte due to their excellent electrochemical stability and protection film forming ability. LiDFOB and Tris(trimethylsilyl)borate (TMSB) were chosen as additive of 1 mol/L LiPF6 FEC/Propylene carbonate (PC)/Dimethyl carbonate (DMC) electrolyte for LiNi0.5Mn1.5O4 battery. The electrochemical performances of the electrolytes LiDFOB and additive TMSB have been systematically investigated. The differences between these two electrolytes were also demonstrated by SEM and cyclic voltammetry. The results showed that decomposed potential of the electrolyte with LiDFOB+additive TMSB can be enhanced to 5.5 V (vs. Li/Li+) and the Al current collector could be effectively passivated. The initial discharge capacity of Li/LiNi0.5Mn1.5O4 half cell operated with electrolyte with LiDFOB and TMSB was 126.8 mA?h/g, the coulomb efficiency was 99%. After 200 cycles, the discharge specific capacity was 108.2 mA?h/g, and it added retained 85.3% of its initial discharge capacity, while it is only 60.7% after 85 cycles for the one operated with the same basic electrolyte but without additive.
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