Overlooked P‐Doping Destroys CoSe2’s Lattice Ordered Structure for Modulating the Deposition of Li2S

Abstract

The improvement of Li2S formation during the discharge process of lithium‐sulfur batteries (LSBs) poses a significant challenge in practical application. It has been proven that adsorbing soluble polysulfides and catalytically inducing Li2S deposition is an effective strategy. In this study, it is found that sodium hypophosphite (NaH2PO2) as a phosphorus source can significantly reduce the crystallinity of CoSe2, since multiple doping with phosphorus results in a decrease of the lattice orderliness. Consequently, the resultant samples with low crystallinity exhibits characteristics akin to amorphous structures, abundant with dangling bonds and unsaturated sites, and these features impart strong adsorption and catalytic effects on sulfur species. Specifically, they are capable of effectively modifying the deposition mode of Li2S, thus achieving high‐capacity retention during long cycling processes. Furthermore, this study delves into the variations in galvanostatic discharge curves during prolonged cycling processes, providing new structural design and mechanistic insights for the analysis and application of LSBs.