Electrical and electrochemical properties of γ-Li2CuZrO4

The γ-Li₂CuZrO₄ with a double rock-salt structure, as a lithium-ion compound, has never been reported on their physical and physicochemical properties. The γ-Li₂CuZrO₄ was prepared by a solid-state reaction process. X-ray diffraction was used to analyze the structure of the products. Its electrical properties were characterized by both DC and AC measurements in the temperature range from 133 to 1273 K. Cyclic voltammetry and galvanostatic cell cycling were also employed to evaluate its electrochemical performance. It is found to be a pure electronic semiconductor with a fairly high conductivity (10⁻⁵ S/cm at 133 K, 10⁻² S/cm at 300 K and 10⁻¹ S/cm at 1173 K). The average activation temperature is 14.4 kJ/mol. When increasing the temperature above 1073 K, a phase transition from γ to β takes place. When reacting with lithium in an electrochemical cell, γ-Li₂CuZrO₄ decomposes into three phases during the initial discharge process, and possesses a reversible capacity of about 70 mAh/g.