Interface between Sodium Metal and Nasicon Solid-State Electrolyte

Metal solid-state battery is deem as the future energy storage system due to its high energy density and safety. Sodium-metal solid-state battery has the cost advantage over lithium-based system due to its availability in the earth’s crust. Beside achieving high ionic conductivity, an intimate and robust electrode/electrolyte is vital to the battery performance. In this study, the surface composition of NASICON electrolyte compatibility with sodium metal is studied. It is realised that the presence of functional groups on the surface has led to high interfacial impedance between the sodium and electrolyte. Such functional groups can be removed by a simple thermal treatment in air. Consequently, the area specific interfacial resistance reduced to 11 Ω cm -1 compared to 1716 Ω cm -1 .