Quantum Materials - 05

Abstract

Chloride-ion solid electrolytes have been widely investigated as core components of membranes, gas sensors, and all-solid-state batteries with high energy densities. Several fast chloride-ion solid electrolytes operating at ambient to intermediate temperatures have been reported, ranging from inorganic metal chlorides and metal-organic compounds to complexes. However, these chlorides have the major drawbacks of being thermally and chemically unstable, which restricts their practical applications[1]. An approach that can combine stability and high chloride ion conductivity is complex anionization with oxygen[2]. However, in this complex oxychloride, oxygen ions may also be conducting species[3] . Herein, we report a new open-framework layered borate chloride, (La1−xCax)(BO2)2Cl1−x (x = 0 - 0.15), which exhibit excellent structural stability under humidity and high temperature. By Ca2+ cation doping, chloride ions were easy to conduct the lattice through the chlorine vacancies, and among the prepared samples, (La_0.9Ca_0.1)(BO₂)₂Cl_0.9, exhibited the highest conductivity of 1.84×10₋₄ S cm_–1 at 700 °C, which was about 30 times higher than that of La(BO₂)₂Cl.