Furnishing Continuous Efficient Bidirectional Polysulfide Conversion for Long‐Life and High‐Loading Lithium–Sulfur Batteries via the Built‐In Electric Field

Abstract

AbstractMost catalysts cannot accelerate uninterrupted conversion of polysulfides, resulting in poor long‐cycle and high‐loading performance of lithium–sulfur (Li–S) batteries. Herein, rich p‐n junction CoS2/ZnS heterostructures embedded on N‐doped carbon nanosheets are fabricated by ion‐etching and vulcanization as a continuous and efficient bidirectional catalyst. The p‐n junction built‐in electric field in the CoS2/ZnS heterostructure not only accelerates the transformation of lithium polysulfides (LiPSs), but also promotes the diffusion and decomposition for Li2S the from CoS2 to ZnS avoiding the aggregation of lithium sulfide (Li2S). Meanwhile, the heterostructure possesses a strong chemisorption ability to anchor LiPSs and superior affinity to induce homogeneous Li deposition. The assembled cell with a CoS2/ZnS@PP separator delivers a cycling stability with a capacity decay of 0.058% per cycle at 1.0 C after 1000 cycles, and a decent areal capacity of 8.97 mA h cm−2 at an ultrahigh sulfur mass loading of 6 mg cm−2. This work reveals that the catalyst continuously and efficiently converts polysulfides via abundant built‐in electric fields to promote Li–S chemistry.