Chemical compatibility between garnet-like solid state electrolyte Li6.75La3Zr1.75Ta0.25O12 and major commercial lithium battery cathode materials

Abstract

High-temperature chemical compatibilities between garnet-like solid state electrolyte of Li6.75La3Zr1.75Ta0.25O12 (LLZTO) and the four major commercial lithium battery cathode materials, i.e., LiCoO2 (LCO), LiMn2O4 (LMO), LiNi0.33Co0.33Mn0.33O2 (NCM) and LiFePO4 (LFP) were investigated by X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS), respectively. The same volume fraction of LLZTO and electrode powders were mixed and heated at 400–900 °C for 1 h. According to the results by XRD, LMO and LFP react with LLZTO at approximately 500 °C. The Raman data reveal that both LCO and NCM can react with LLZTO at approximately 700 °C, which lead to generate LaCoO3 and LaCo1−xMnxO3 with a rhombohedral symmetry, respectively.