Room-Temperature All-Solid-State Sodium Battery Based on Bulk Interfacial Superionic Conductor

All-solid-state sodium batteries (ASSSBs) are attractive alternatives to lithium-ion batteries for grid-scale energy storage due to their high safety and ubiquitous distribution of Na sources. A critical component for ASSSB is sodium-ion conducting solid-state electrolyte (SSE). Here, we report a high-performance sodium-ion SSE with the recently developed bulk interfacial superionic conductor (BISC) concept. The ionic conductivity and areal conductance of the Na+ BISC at 25 degrees C reaches 6.5 x 10(-4) S cm(-1) and 260 mS cm(-2), respectively. Using NaxCo0.7Mn0.3O2 (x approximate to 1.0, NaCMO) as the cathode active material, all-solid-state Na parallel to NaCMO batteries exhibiting small overpotential and similar to 180 cycle life are demonstrated under room temperature. This approach may also be used to prepare other metal ion, such as Mg2+, Al3+, and K+, based all-solid-state batteries.