Li2ZrO3 based Li-ion conductors doped with halide ions & sintered in oxygen-deficient atmosphere

Abstract

All-solid-state batteries have recently attracted much attention for their high energy density and safety. Li2ZrO3-based Li-ion conductors with high electrochemical stability have potential applications for electrolytes in all-solid-state batteries. In this work, comparative investigations of Li2ZrO3 and halogen doped Li2ZrO3 ceramics were conducted by sintering at 700 °C in air or in oxygen-deficient atmosphere which was induced by a simple setup covering with corundum crucible. The analysis of phase composition reveals that the undoped Li2ZrO3 ceramic sintered in air contains pure monoclinic phase, while halogen-doped Li2ZrO3 sintered in air and all ceramics sintered in oxygen-deficient atmosphere are simultaneously composed of monoclinic and tetragonal phases. Li2ZrO3 ceramic with tetragonal phases has higher conductivity (0.28 mS cm−1 for undoped Li2ZrO3) than the pure monoclinic Li2ZrO3 (0.07 mS cm−1), and halogen doping can further enhance the conductivity of Li2ZrO3 ceramics higher than 0.5 mS cm−1 at room temperature.