Instability of lithium bis(fluorosulfonyl)imide (LiFSI)–potassium bis(fluorosulfonyl)imide (KFSI) system with LiCoO<sub>2</sub> at high voltage

Instability of lithium bis(fluorosulfonyl)imide (LiFSI)–potassium bis(fluorosulfonyl)imide (KFSI) system with LiCoO₂ at high voltage

Zhang Shu^a), Li Wen-Jun^a), Ling Shi-Gang^a), Li Hong†^a), Zhou Zhi-Bin^b), Chen Li-Quan^a)

SEM micrographs of (a)–(c) pristine LiCoO₂ and (d)–(f) LiCoO₂ electrode surfaces after 20 charge-discharge cycles for Li/LiFSI–KFSI ( χ _LiFSI: χ _KFSI = 0.41: 0.59)/LiCoO₂ cell at a charge/discharge rate of 0.2/0.2 C at 80 °C.