Fig. 7: Electrochemical performance of the Na-Sn | NPSC | NTC | CFNM all-solid-state batteries.

a Schematic illustration of the solid-state batteries, comprising NaCu_0.12Ni_0.22Fe_0.33Mn_0.33O₂ (CFNM) positive electrode, NaTaCl₆ (NTC) solid electrolyte, Na_2.9375PS_3.9375Cl_0.0625 (NPSC) interfacial buffer layer, and Na₂Sn (Na-Sn) alloy negative electrode. b, c The rate performance of Na-Sn | NPSC | NTC | CFNM solid-state battery cycled under 14, 28, 42, 70, 112, and 140 mA g⁻¹ at 27 °C: (b) rate capability, and (c) the corresponding 2nd charge/discharge profiles at each rate. d The rate performance of an identical cell cycled under 14, 28, 70, 140, 280 and 420 mA g⁻¹ at 50°C. e The voltage profiles of the solid-state cell upon cycling at 27 °C and 70 mA g⁻¹. f, g Long-term cycling stability of the same solid-state battery at (f) 27°C, and (g) 50 °C. The cell was charged/discharged at 28 mA g⁻¹ during the first two cycles and subsequently under 70 mA g⁻¹ at 27°C or under 140 mA g⁻¹ at 50 °C for the rest of the test. Source data for figure are provided as a Source Data file.