Fig. 1. (a) The XRD pattern and (b) SEM image of the LATP powder. The surface morphologies of (c) Al₂O₃@PE and (d) LATP@PE separators.

Fig. 2. Charge–discharge curves of (a) LCO-SOC400 cell and (b) LMO-SOC650 cell for the first cycle. The red and blue curves represent the cells using Al₂O₃ coated and LATP coated separators, respectively.

Fig. 3. Discharge capacity retention of (a) LCO-SOC400 cell and (b) LMO-SOC650 cell. Discharge profiles of (c) LCO-SOC400 cells and (d) LMO-SOC650 cells at different cycles.

Fig. 4. EIS spectra for (a) the LCO-SOC400 cells and (b) the LMO-SOC650 cells after 50 cycles. R_b: ohmic resistance; R_a: resistance of SEI at anode; R_c: resistance of CEI at cathode; CPE: constant phase element.

Fig. 5. SEM images of (a), (b) Al₂O₃@PE and (c), (d) LATP@PE separators retrieved from the cells after 50 cycles.

Fig. 6. SIMS profiles collected on the anode electrodes retrieved from (a) LCO-SOC400 cell and (b) LMO-SOC650 cell after 50 cycles. (c) Raman spectra of LCO electrodes retrieved from LCO-SOC400 with LATP@PE and Al₂O₃@PE separators. (d) Schematic illustration of the TM dissolution and decomposition process.

Table 1. The detailed results of fitting the spectra with an equivalent circuit model.