Na3SbS4: A Solution Processable Sodium Superionic Conductor for All-Solid-State Sodium-Ion Batteries

Abstract

All-solid-state sodium-ion batteries that operate at room temperature are attractive candidates for use in large-scale energy storage systems. However, materials innovation in solid electrolytes is imperative to fulfill multiple requirements, including high conductivity, functional synthesis protocols for achieving intimate ionic contact with active materials, and air stability. A new, highly conductive (1.1 mS cm−1at 25 °C, Ea=0.20 eV) and dry air stable sodium superionic conductor, tetragonal Na3SbS4, is described. Importantly, Na3SbS4can be prepared by scalable solution processes using methanol or water, and it exhibits high conductivities of 0.1–0.3 mS cm−1. The solution-processed, highly conductive solidified Na3SbS4electrolyte coated on an active material (NaCrO2) demonstrates dramatically improved electrochemical performance in all-solid-state batteries. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim