Bilayer Halide Electrolyte Design Enabling Excellent Interface Stability between a Li-Metal Anode and a Halide Solid Electrolyte
Boyi Zhang, Musheng Wu, Baozhen Sun, Jing Shi, Gang Liu, Bo Xu, Chuying Ouyang
Abstract
Halide solid electrolytes (SEs) with high ionic conductivity and good chemical stability are promising materials for all-solid-state Li-metal batteries (ASS-LMBs). However, the poor interfacial compatibility with Li metal has impeded their extensive applications in ASS-LMBs. To address this problem, here, we propose a novel bilayer halide interface Li 3 YCl 6 (LYC)/Li 3 OCl(LOC)/Li. The stability and Li-ion transport of LYC/LOC/Li are systematically studied by employing density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations. Our results show that the stability of the LYC/Li interface can be greatly improved after LOC coating on LYC. In particular, we found that the diffusion of Li-ions is predominant along the boundary of the LYC/LOC/Li, and the conductivity and activation energy of Li-ions at the interface are 160 mS/cm (300 K) and 0.146 eV, respectively, which are superior to the counterparts of bulk LYC. Our results provide theoretical guidance for enabling halide compatibility with Li metal.