Inhibiting manganese(Ⅱ) from catalyzing electrolyte decomposition in lithium-ion batteries

作者：Xuehuan Luo; Lidan Xing^*; Jenel Vatamanu; Jiawei Chen; Jiakun Chen; Mingzhu Liu; Cun Wang; Kang Xu; Weishan Li

来源：Journal of Energy Chemistry, 2022, 65(02): 1-8.

A once overlooked source of electrolyte degradation incurred by dissolved manganese(Ⅱ) species in lithium-ion batteries has been identified recently. In order to deactivate the catalytic activity of such manganese(Ⅱ) ion, 1-aza-12-crown-4-ether(A12 C4) with cavity size well matched manganese(Ⅱ) ion is used in this work as electrolyte additive. Theoretical and experimental results show that stable complex forms between A12 C4 and manganese(Ⅱ) ions in the electrolyte, which does not affect the solvation of Li ions. The strong binding effect of A12 C4 additive reduces the charge density of manganese(Ⅱ) ion and inhibits its destruction of the PF6-structure in the electrolyte, leading to greatly improved thermal stability of manganese(Ⅱ) ions-containing electrolyte. In addition to bulk electrolyte, A12 C4 additive also shows capability in preventing Mn2+ from degrading SEI on graphite surface. Such bulk and interphasial stability introduced by A12 C4 leads to significantly improved cycling performance of LIBs.

• 单位
  华南师范大学