Tris(2,2,2-trifluoroethyl) phosphate, as a flame-retarding cosolvent, is initially mixed with γ-butyrolactone for the first time to formulate a nonflammable electrolyte, in which lithium difluoro(oxalato)borate is added as a film-forming additive. This electrolyte possesses a higher safety level and better wettability compared with a commercial electrolyte. The conductivity of this electrolyte is 7.40 mS cm^–1 at room temperature. This high-safety electrolyte helps graphite/LiNi_0.5Co_0.2Mn_0.3O₂ full cells to obtain good electrochemical performance. The capacity retention after 200 cycles at room temperature (1C) is 90.8% and the capacity retention of 100 cycles at 60 °C (1C) is up to 86.7%, which are better than those of the commercial electrolyte. To further analyze the relationships between compositions of electrolytes and the electrochemical performance of the full cells, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) measurements are performed.

中文翻译：

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磷酸三（2,2,2-三氟乙基）酯作为锂离子电池中不可燃电解质的助溶剂

首先将磷酸三（2,2,2-三氟乙基）酯作为阻燃助溶剂，首次与γ-丁内酯混合以配制不易燃的电解质，其中以薄膜形式添加二氟（草酸）硼酸锂-形成添加剂。与市售电解质相比，该电解质具有更高的安全级别和更好的润湿性。该电解质在室温下的电导率为7.40 mS cm ^–1。这种高安全性的电解质有助于石墨/ LiNi _0.5 Co _0.2 Mn _0.3 O ₂充满电的电池以获得良好的电化学性能。在室温（1C）下200个循环后的容量保持率为90.8％，在60°C（1C）下100个循环的容量保持率高达86.7％，这比市售电解质要好。为了进一步分析电解质的组成与全电池的电化学性能之间的关系，进行了X射线光电子能谱（XPS）和扫描电子显微镜（SEM）测量。