Lithium Metal-Compatible Antifluorite Electrolytes for Solid-State Batteries
Pengcheng Yu, Haochang Zhang, Fiaz Hussain, Jing Luo, Wen Tang, Jiuwei Lei, Lei Gao, Denys S. Butenko, Changhong Wang, Jinlong Zhu, Wen Yin, Hao Zhang, Songbai Han, Ruqiang Zou, Wei Chen, Yusheng Zhao, Wei Xia, Xueliang Sun
Abstract
Lithium (Li) metal solid-state batteries feature high energy density and improved safety and thus are recognized as promising alternatives to traditional Li-ion batteries. In practice, using Li metal anodes remains challenging because of the lack of a superionic solid electrolyte that has good stability against reduction decomposition at the anode side. Here, we propose a new electrolyte design with an antistructure (compared to conventional inorganic structures) to achieve intrinsic thermodynamic stability with a Li metal anode. Li-rich antifluorite solid electrolytes are designed and synthesized, which give a high ionic conductivity of 2.1 × 10 –4 S cm –1 at room temperature with three-dimensional fast Li-ion transport pathways and demonstrate high stability in Li–Li symmetric batteries. Reversible full cells with a Li metal anode and LiCoO 2 cathode are also presented, showing the potential of Li-rich antifluorites as Li metal-compatible solid electrolytes for high-energy-density solid-state batteries.