New lithium-conducting nitride glass Li3BN2

Abstract

Novel nitride glass electrolyte Li3BN2 was prepared from Li3N and BN via a mechanochemical process using planetary ball milling. Raman and X-ray photoelectron spectroscopies revealed that the glass was composed of Li+ and BN23− ions. The Li3BN2 glass exhibited good ductility, and the powder-compressed pellet showed a relative density of 84%. The hot-pressed pellet of the Li3BN2 glass showed a conductivity of 1.3 × 10−5 S cm−1 at 25 °C, which is much higher than that of oxide-based glass electrolytes such as Li3BO3 glass and LiPON thin films. Moreover, Young's modulus of the Li3BN2 glass was 51.1 GPa, which is an intermediate value between sulfides and oxides. The Li symmetric cell using the Li3BN2 glass electrolyte was cycled stably at 100 °C without short-circuiting. Nitride glassy materials are promising electrolytes for all-solid-state batteries because of their high conductivity, good mechanical properties, and electrochemical stability.