Bifunctional Interphase-Enabled Li 10 GeP 2 S 12 Electrolytes for Lithium–Sulfur Battery

作者：Hongli Wan, Sufu Liu, Tao Deng, Feng Xu, Jiaxun Zhang, Xinzi He, Xiao Ji, Xiayin Yao, Chunsheng Wang · 发表于：ACS Energy Letters · 年份：2021 · DOI：10.1021/acsenergylett.0c02617 · 被引用次数：184 · 研究领域：Advanced Battery Materials and Technologies、Advancements in Battery Materials、Advanced Battery Technologies Research

Li 10 GeP 2 S 12 (LGPS) has a high ionic conductivity and compatibility with sulfur cathodes; however, the instability of LGPS against Li and Li dendrite growth still remains unsolved. Here, we solved these two challenges by forming a lithiophilic–lithiophobic gradient interlayer interphase layer between Li and LGPS through the sequential reduction of salts and solvent in Mg(TFSI) 2 -LiTFSI-DME liquid electrolyte at the LGPS/Li interface (TFSI = bis(trifluoromethanesulfonyl)imide; DME = dimethoxyethane). Mg(TFSI) 2 -LiTFSI is first reduced, forming a lithiophilic Li x Mg alloy-rich layer on the lithium surface and a lithiophobic LiF-rich layer on top of Li x Mg due to the lithiophobicity difference. The later reduced DME solvent forms a flexible organic polymer between the LiF-rich layer and LGPS. After evaporation of DME solvent, the Li/LGPS/Ni-Li 2 S-LiTiS 2 all-solid-state battery shows a reversible capacity of 699.7 mAh g –1 (1.07 mAh cm –2 ) based on the mass of Ni-Li 2 S-LiTiS 2 at 100 mA g –1 (0.26 mA cm –2 ). The rational design of a solid electrolyte interface between a Li anode and LGPS electrolyte opens a new opportunity to develop high-performance all-solid-state lithium batteries.