The Li-ion conductivity was measured by adding 0.15 g Li3InCl6 or LPSCl (NEI corporation) powder into a PEEK (Polyether ether ketone) cell with a diameter of 10 mm and further pressed at 300 MPa. EIS measurements were carried out at 3-ton pressure and room temperature (25 °C, unless specified), in the frequency range of 10 mHz to 7 MHz with 10 mV of applied sinus amplitude. For half cells, firstly, 80 mg LPSCl was added in the PEEK cell with a diameter of 10 mm and pressed at 3 tons. The cathode composite was prepared by hand-mixing the NCA (LIC@NCA) and LPSCl in a ratio of 7:3 (wt.%) in an agate mortar and pestle inside an Ar-filled glovebox. 9 to 13 mg of as-prepared cathode composite powder was placed on one side of the LPSCl pellet and pressed at 375 MPa.