Highly Catalytic CoP@N, P-Codoped Porous Carbon Synthesized by a Supramolecular Gel and Salt Template Method for Li–S Batteries

Lithium polysulfides (LiPSs) shuttling effect is the main problem to be solved for cathode materials of lithium–sulfur batteries. The adsorption and catalytic conversion of LiPSs by host materials have become the main focus of cathode materials. In this work, transition metal phosphides are combined with three-dimensional carbon nanosheets to form an efficient and stable sulfur host material. The designed composite material is effective in solving the problems of slow reaction kinetics of Li–S batteries and LiPSs shuttling. Here, through the supramolecular self-assembly process of melamine and phytic acid, combined with soluble salt template technology, N- and P-codoped three-dimensional hierarchical porous carbon materials with uniformly dispersed CoP nanoparticles were efficiently synthesized. The catalytic effect of CoP nanoparticles improves the reaction kinetics effectively of LiPS conversion. The strong polarity of CoP nanoparticles is beneficial to the adsorption of polysulfide ions. Moreover, the high specific area provides more LiPS adsorption sites, and the doping of N and P heteroatoms further increases the active sites of the composites. The experimental results and theoretical calculations show that the introduction of CoP promotes the conversion of LiPSs and accelerates the nucleation rate of Li2S, thereby improving the electrochemical performance of the composite as a sulfur host for lithium–sulfur batteries.