A Ternary (P, Se, S) Covalent Inorganic Framework as a Shuttle Effect‐Free Cathode for Li–S Batteries
Lu Chen, Ting He, Kexuan Liao, Hang Lu, Jian Ma, Yutong Feng, Shuo Meng, Chi Zhang, Jinhu Yang
Abstract
Abstract Developing 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), P 4 Se 6 S 40 , is explored, by simply comelting powders of P, S, and Se. The P 4 Se 6 S 40 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 Li 3 PS 4 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 P 4 Se 6 S 40 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.