Tris(trimethylsilyl) phosphite (TMSP) is well known as an effective electrolyte additive that significantly improves the electrochemical performance of high-voltage lithium-ion batteries. This work reveals that TMSP is oxidized more readily than an electrolyte solvent, is more difficult to be reduced, and exhibits high reactivity with HF. The significant role of TMSP in HF removal is demonstrated by full-cell experiments. We suggest a mechanism through which TMSP removes HF molecules from the electrolyte, forms a cathode–electrolyte interphase with outstanding properties on the cathode surface while not undergoing a side reaction at the anode surface. In addition, the fact that TMSP can be oxidized more readily than vinylene carbonate is what results in the synergistic effect observed when the two additives are used together.

中文翻译：

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为什么亚磷酸三（三甲基甲硅烷基）酯可以有效地用作高压锂离子电池的添加剂？†

众所周知，亚磷酸三（三甲基甲硅烷基）酯是一种有效的电解质添加剂，可显着提高高压锂离子电池的电化学性能。这项工作表明，TMSP比电解质溶剂更容易被氧化，更难以还原，并且与HF表现出高反应性。全细胞实验证明了TMSP在去除HF中的重要作用。我们提出了一种机制，TMSP通过该机制从电解质中除去HF分子，在阴极表面上形成具有出色性能的阴极-电解质中间相，而不会在阳极表面上发生副反应。另外，TMSP比碳酸亚乙烯酯更容易被氧化的事实是当两种添加剂一起使用时观察到的协同作用。