Abstract Triisopropyl borate electrolyte additive is introduced to improve the cycled stability of LiNi0.6Co0.2Mn0.2O2 (NCM622) cathode operating under 4.5 V charging-cutoff voltage. Through characterizations analysis from SEM, TEM, XPS, ICP, XRD and EIS, it reveals that triisopropyl borate additive can be oxidized on the cathode and form a relatively stable protective film on the NCM622 cathode surface, which has the ability to inhibit the decomposition of carbonate electrolyte solvents and improve the electrochemical stability of LiNi0.6Co0.2Mn0.2O2 cathode. When 1.0 wt% triisopropyl borate additive adding, the NCM622/Li cells achieve the discharge capacity retention of 82.7% after 300 cycles at the voltage of 3.0–4.5 V, while that of the cells without additive is only 50.0%.

中文翻译：

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硼酸三异丙酯作为电解质添加剂用于提高 LiNi0.6Co0.2Mn0.2O2 正极的高压稳定性

摘要 为了提高LiNi0.6Co0.2Mn0.2O2 (NCM622)正极在4.5 V充电截止电压下的循环稳定性，引入硼酸三异丙酯电解质添加剂。通过SEM、TEM、XPS、ICP、XRD、EIS等表征分析表明，硼酸三异丙酯添加剂可在阴极氧化，在NCM622阴极表面形成相对稳定的保护膜，具有抑制其分解的能力。碳酸盐电解质溶剂，提高LiNi0.6Co0.2Mn0.2O2正极的电化学稳定性。当添加1.0 wt%硼酸三异丙酯添加剂时，NCM622/Li电池在3.0-4.5 V电压下循环300次后的放电容量保持率为82.7%，而未添加添加剂的电池仅为50.0%。