P-doped Mo2C nanoparticles embedded on carbon nanofibers as an efficient electrocatalyst for Li-S batteries

Designing a reliable sulfur host that can simultaneously catalyze sulfur redox reactions and suppress polysulfides shuttling is highly desired for the development of advancing Li-S batteries. In this work, P-doped Mo2C nanoparticles anchoring on carbon nanofibers (CNF) is prepared via an organic–inorganic nanohybridization process. The interwoven CNF networks establish continuous electrons transport pathways and provide a large surface area for loading P-Mo2C nanoparticles. The P dopant tunes the electronic structure of Mo2C, which endows P-Mo2C with enhanced polysulfides adsorption ability and improved sulfur redox kinetics. Leveraging these advantages, the Li-S battery shows excellent electrochemical properties, delivering a high specific capacity of 1174 mA·h·g−1 at 0.2C, and maintaining over 1200 stable cycles at 1C with a low capacity attenuation rate of 0.043 % per cycle. At a S loading of 4.88 mg·cm−2 and E/S ratio of 8.25 μL·mg−1, the Li-S battery attains an areal capacity of 6.50 mA·h·cm−2 at 0.05C. These results highlight the promising application potential of P-Mo2C@CNF as an effective electrocatalyst for Li-S batteries.