fig7

Figure 7. EIS analysis of three-electrode NMC-811||Li-Cu cells with QSPE-2 and QSPE-3 as electrolytes. Cells were cycled between 3.0 and 4.3 V, at C/50 (2 cycles) and C/20 (30 cycles). EIS spectra were collected during cycling at C/20, at the end of charge (EoC) and at the end of discharge (EoD), after one hour of resting. (A) Specific capacity (left axis) and coulombic efficiency (right axis); (B) open circuit potential of the positive electrode (E_+,OCP) vs. Li/Li⁺, at the EoC and EoD, upon cycling time (each point corresponds to one cycle at C/20); (C) evolution of the main resistances of the positive electrode impedance spectra, at the EoC and EoD, with QSPE-2 as electrolyte; (D) evolution of the main resistances contributing to the positive electrode impedance spectra, at the EoC and EoD, with QSPE-3 as electrolyte.