The interface compatibility between Li metal and the optimum SPE8:1:1 was evaluated by Li plating-stripping cycling test. The symmetric Li|SPE8:1:1|Li cell was cycled at constant current densities of 0.1 mA cm -2 for 1 hour polarisation at each step at 50 °C. As shown in Figure , the long-term cycling of the Li|SPE8:1:1|Li cell showed very stable performance with an overpotential of 50 mV over 150 cycles at 50 °C, and there was no sign of short circuit, indicating that SPE8:1:1 has good compatibility with Li metal anode. The interfacial resistance decreased after 150 cycles (insert in Figure ), indicating that the SPE8:1:1 continually adjusted to enhance its contact with the lithium surface. The surface image and morphology of Li metal after 150 cycles is shown in Figure -f. A smooth and dense Li metal surface was observed with no signs of Li dendrites or dead Li, indicating a uniform Li deposition process and the formation of a stable SEI layer. The cross-section SEM of the platted side displayed a uniform and dense interface, which confirmed the excellent mechanical and electrochemical properties of SPE8:1:1 that allows it to accommodate volume changes of the Li anode, thereby sustaining facile and reversible Li platingstripping. The prepared all-solid-state Li|SPE8:1:1|c-LFP/c-LMO cell is illustrated in Figure . Figure presents the cycling performance of the Li|SPE8:1:1|c-LFP cell, which was cycled at C/5 rate at 50 °C between 2.5 and 4 V. The c-LFP cathode was prepared using the designed SPE as the binder to maintain the Li percolation within the cathode structure (more details are mentioned in the experimental section). Thereby the LMB constructed here is all-solid-state avoiding any trace of liquid wetting and the cell delivered 160 mAh g -1 initial discharge capacity. The performance then increased to 165 mAh g -1 after 20 cycles and stabilized, demonstrating the self-adaptability of SPE8:1:1 membrane over cycling. After 100 cycles, the cell maintained an exceptional capacity retention of 99.2% and achieved nearly 100% coulombic efficiency (CE) throughout cycling. Other works are summarized in supplementary Table which clearly outlines the novelty of our PiHCIL-SPE8:1:1 membrane and thereby suggests an impressive performance in comparison with the existing literature using similar cathode active loading and applied current density. Charge-discharge profiles at various cycle numbers are displayed in Figure . The polarization remains low (180 mV) after 100 cycles, demonstrating the high stability of SPE8:1:1. AC impedance profiles (Fig. ) showed an initial increase due to SEI To assess the potential for wider applications of the prepared PiHCIL-SPEs working with high voltage materials, we assembled Li||c-LMO cells with a cathode loading of 3 mg cm - 2 with SPE8:1:1. Figure illustrates the cycling performance of the Li|SPE8:1:1|c-LMO cell at 0.2C in the voltage range between 3 and 4.3 V. The Li|SPE8:1:1|c-LMO cell maintain 80% discharge capacity after 50 cycles and interfacial resistance (Fig. ) slowly increases through cycling. Fig. presents the charge-discharge profiles at different cycle numbers. The capacity decay maybe due to the dissolution of unstable manganese in LMO which is a common issue of high manganese active materials. The cell was further subjected to a rate capability test at various rates from C/20 to 2 C as show in Figure . The SPE shows satisfactory discharge capacity retention of 55% from C/20 to 2C, demonstrating superior tolerance to high current rate. The exceptional rate performance and cycling stability of the Li|SPE8:1:1|c-LMO cell confirms the potential of the designed SPE to work with high voltage cathodes and further applications to high energy storage systems.