A novel strategy for selecting an additive based on understanding the influence of different functional groups on electrochemical characteristics is adopted. N,N-Diethylamino trimethylsilane (DEATMS) is tested as a bifunctional electrolyte additive to scavenge H₂O and neutralize HF in the electrolyte and enhance the behaviour of graphite/LiNi_0.5Co_0.2Mn_0.3O₂ cells operating at a high voltage (4.5 V vs. Li/Li⁺) or elevated temperature (55 °C). With 2% DEATMS, no LiPF₆ hydrolysis species is found after storage at 55 °C for 6 days, even with a moisture content of 2000 ppm in the electrolyte. In addition, the graphite/LiNi_0.5Co_0.2Mn_0.3O₂ cells containing DEATMS show cycling performances superior to those of the cells without DEATMS upon cycling for 100 cycles at a high voltage (85.5% vs. 72.0%) or high temperature (81.2% vs. 70.6%). The sacrificial oxidation of DEATMS on the cathode surface restricts direct contact between the electrolyte and cathode, improving the electrochemical performance. The ex situ surface analysis of the electrodes after cycling indicates that both the electrolyte decomposition and Mn dissolution are inhibited by the deposition of DEATMS oxidation products.

中文翻译：

---

用于清除H ₂ O / HF的双功能电解质添加剂，并在高压下增强了石墨/ LiNi _0.5 Co _0.2 Mn _0.3 O ₂电池的性能†

采用了一种基于了解不同官能团对电化学特性的影响来选择添加剂的新颖策略。N，N-二乙氨基三甲基硅烷（DEATMS）作为双功能电解质添加剂经过测试，可清除电解质中的H ₂ O和中和HF，并增强在高压（4.5下工作）的石墨/ LiNi _0.5 Co _0.2 Mn _0.3 O ₂电池的性能V与对于Li / Li ⁺）或升高的温度（55℃）。具有2％的DEATMS，无LiPF ₆在55°C下储存6天后，即使电解液中的水分含量为2000 ppm，也会发现水解物质。此外，含有DEATMS的石墨/ LiNi _0.5 Co _0.2 Mn _0.3 O ₂电池在高压（85.5％vs. 72.0％）或高温（81.2）下循环100次后，其循环性能优于没有DEATMS的电池。％和70.6％）。DEATMS在阴极表面的牺牲性氧化限制了电解质与阴极之间的直接接触，从而改善了电化学性能。该易地 循环后电极的表面分析表明，DEATMS氧化产物的沉积会抑制电解质的分解和Mn的溶解。