A new 3-D open-framework Li-rich vanadoborate and its high ionic conductivity after transforming into glasses

Abstract

A new 3-D open-framework Li-rich vanadoborate Li₁₀[V₁₂B₁₈O₆₀H₆]·28H₂O (1) has been successfully synthesized under hydrothermal conditions. The framework of this compound is constructed by the connection of [V₁₂B₁₈O₆₀H₆]¹⁰⁻ clusters linked through hydrogen bonds and the charge is compensated by disordered Li⁺ ions. This compound can undergo a phase transition from the crystalline phase to the glassy phase at 220 °C. Interestingly, after transforming into the glass phase, this material exhibits a high Li⁺ ionic conductivity of 1.77 × 10⁻² S cm⁻¹ at 400 °C and the activation energy of lithium ion transport is 0.48 eV.