Fig. 4: PCE enables improved interphasial and interfacial ion transport kinetics.

a–c 2D EXSY NMR of PCE at different mixing time of 1 ms, 5 ms and 100 ms. d Schematic illustration of the isotope exchange method for revealing the ion conduction pathway. e 6Li solid-state NMR spectra of the pristine PCE and the PCE cycled in 6Li-6Li symmetric cells. f EIS plots of SS|PCE|SS and SS|LATP|SS cells showing the grain boundary resistance at 30 °C. SS refers to stainless steel blocking electrodes. g Temperature-dependent ionic conductivity of PCE and the Arrhenius fitting in the form of \(\sigma=A{{e}^{-}}^{\frac{{E}_{a}}{{kT}}}\). h Evolution of EIS plots for Li0|PCE|Li0 cell when cycling at 0.2 mA/cm2 at 50 °C. Inset is the evolution of EIS plots for Li0|LATP|Li0 cell when cycling at 0.05 mA/cm2 at 50 °C. i SEM images showing the surface morphology of Li0 deposits after discharging a Li0|PCE|Cu cell at 0.2 mA/cm2 and 22 °C. j Voltage-time profile and EIS plot evolution (inserted figure) when continuously discharging a Li0|PCE|Li0 cell at 0.2 mA/cm2 and 50 °C for 30 h.