New lithium-conducting nitride glass Li3BN2

Abstract Novel nitride glass electrolyte Li 3 BN 2 was prepared from Li 3 N 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 BN 2 3− ions. The Li 3 BN 2 glass exhibited good ductility, and the powder-compressed pellet showed a relative density of 84%. The hot-pressed pellet of the Li 3 BN 2 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 Li 3 BO 3 glass and LiPON thin films. Moreover, Young's modulus of the Li 3 BN 2 glass was 51.1 GPa, which is an intermediate value between sulfides and oxides. The Li symmetric cell using the Li 3 BN 2 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.