Higher charging cutoff voltages of LiCoO₂/graphite pouch-cells with high energy density can meet the advanced requirement of new generation lithium-ion batteries. However, the poor cycling performance derives from severe the electrolyte's decomposition on interface of the cathode/electrolyte at high charging cutoff voltage limits its wider commercial application. To resolve these detrimental effects of battery at high operating voltage, a novel bifunctional electrolyte additive (PTSI) is added into electrolyte for the LiCoO₂/graphite pouch-cells. Upon operating at higher charging cut-off voltage (4.4 V) after 200 cycles, the LiCoO₂/graphite pouch-cells with 1.0 wt.% PTSI in the electrolyte reveals preferable cycle performance over those in baseline electrolyte. The capacity retention of the pouch-cells with 1.0 wt. % PTSI in the electrolyte is 95.33% after 200 cycles, which is only 61.74% for those in baseline electrolyte. The results of electrochemical and spectroscopic techniques indicate that PTSI decomposes before the electrolyte solvents are consumed, and then took part in the interface layer formation on the interfaces of the electrodes, improving the cells performance. This work develops the novel bifunctional electrolyte additive that meets the requirement of a LiCoO₂-based pouch-cells at high voltage.

具有较高能量密度的较高的LiCoO ₂ /石墨袋式电池的充电截止电压可以满足新一代锂离子电池的先进要求。然而，不良的循环性能是由于在高充电截止电压下电解质在阴极/电解质界面上的严重分解所致，限制了其更广泛的商业应用。为了解决在高工作电压下电池的这些有害影响，将新型双功能电解质添加剂（PTSI）添加到LiCoO ₂ /石墨袋式电池的电解质中。在200个循环后以更高的充电截止电压（4.4 V）操作时，LiCoO ₂电解质中PTSI为1.0 wt。％的/石墨袋式电池显示出比基线电解质中更好的循环性能。小袋电池的容量保持率为1.0 wt。在200次循环后，电解液中PTSI的百分比为95.33％，对于基线电解液中的PTSI而言仅为61.74％。电化学和光谱技术的结果表明，PTSI在电解质溶剂被消耗之前分解，然后参与电极界面上的界面层形成，从而改善了电池性能。这项工作开发了新型的双功能电解质添加剂，该添加剂可满足基于LiCoO ₂的高压袋式电池的要求。