Affiliation:
1. School of Chemical Science and Engineering Tongji University Siping Road, 1239 Shanghai 200092 P. R. China
2. Research Center for Translational Medicine East Hospital Tongji University School of Medicine 150 Jimo Rd Shanghai 200092 P. R. China
Abstract
AbstractDeveloping new cathode materials to avoid shuttle effect of Li–S batteries at source is crucial for practical high‐energy applications, which, however, remains a great challenge. Herein, a new class of sulfur‐containing ternary covalent inorganic framework (CIF), P4Se6S40, is explored, by simply comelting powders of P, S, and Se. The P4Se6S40 CIF with open framework enables all active sites available during electrochemical reactions, giving a high capacity delivery. Moreover, introducing Se atoms can improve intrinsic electronic conductivity of S chains yet without remarkably compromising the capacity because Se is also electrochemical active to lithium storage. More importantly, Se atoms in S–Se chains can serve as a heteroatom barrier to block the bonding of S atoms around, effectively avoiding the formation of long‐chain polysulfides during cycling. Besides, stable Li3PS4 with a tetrahedral configuration formed after lithiation works as not only a good ionic conductor to promote Li ion diffusion, but a three‐dimensional spatial barrier and chemical anchor to suppress the dissolution and diffusion of lithium polysulfides (LiPS), further inhibiting the shuttle effect. Consequently, the P4Se6S40 cathode delivers high capacity and excellent capacity retention with even a high loading of 10.5 mg cm−2 which far surpasses the requirement for commercial applications.
Funder
Natural Science Foundation of Shanghai Municipality
Fundamental Research Funds for the Central Universities
Shanghai Municipal Education Commission
National Natural Science Foundation of China
Subject
Mechanical Engineering,Mechanics of Materials,General Materials Science