Anion sublattice design enables superionic conductivity in crystalline oxyhalides
Feipeng Zhao, Shumin Zhang, Shuo Wang, Joel W. Reid, Wei Xia, Jue Liu, Graham King, James A. Kaduk, Jianwen Liang, Jing Luo, Yingjie Gao, Feipeng Yang, Yang Zhao, W.S. Li, Sandamini H. Alahakoon, Jinghua Guo, Yining Huang, Tsun‐Kong Sham, Yifei Mo, Xueliang Sun
Abstract
Solid-state batteries are attractive energy storage systems as a result of their inherent safety, but their development hinges on advanced solid-state electrolytes (SSEs). Most SSEs remain largely confined to single-anion systems (e.g., sulfides, oxides, halides, and polymers). Through mixed-anion design strategy, we develop crystalline Li 3 Ta 3 O 4 Cl 10 (LTOC) and its derivatives with excellent ionic conductivities (up to 13.7 millisiemens per centimeter at 25°C) and electrochemical stability. The LTOC structure features mixed-anion spiral chains, consisting of corner-shared oxygen and terminal chlorine atoms, which induces continuous “tetrahedron-tetrahedron” Li-ion migration pathways with low energy barriers. Additionally, LTOC demonstrates holistic cathode compatibility, enabling solid-state batteries operation at 4.9 volts versus Li/Li + and low temperature, down to −50°C. These findings describe a promising class of superionic conductors for high-performance solid-state batteries.