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)

(a) Charge/discharge curves and (b) specific capacity and Coulombic efficiency vs. cycle number for the Li/LiPF₆–EC:DMC (1:1)/LiFePO₄ cell at a charge/discharge rate of 0.2/0.2 C at room temperature; and (c) charge/discharge curves and (d) specific capacity and Coulombic efficiency vs. cycle number for the Li/LiFSI–KFSI ( χ _LiFSI : χ _KFSI = 0.41 : 0.59)/LiFePO₄ cell at a charge/discharge rate of 0.2/0.2 C at 80 °C.