Mo₂C-Embedded Carbon Nanofibers as the Interlayer in High-Performance Lithium-Sulfur Batteries

Lithium-sulfur batteries (LSBs) are among the most encouraging competitors for the next-generation energy storage system, nevertheless, the shuttle effect resulted from the soluble lithium polysulfides (LiPSs) and slow chemical kinetics hinder the pragmatic application of LSBs. To address those issues, herein, a uniform three-dimensional (3D) structure constructing carbon nanofibers (CNF) with polar Mo₂C nanoparticles (Mo₂C@CNF) was designed and coated onto one side of pristine conventional polypropylene separator (Mo₂C@CNF/PP). The Mo₂C@CNF with high electrical conductivity not only chemically constrained the LiPSs by chemical trapping, but also catalyzed the conversion of LiPSs to Li₂S₂/Li₂S. Cells with Mo₂C@CNF/PP separator presented a high specific capacity of 732.9 mAh g⁻¹; 500 mAh g⁻¹ was kept, due to sluggish capacity decay (0.063 % per cycle), after 500 cycles. Judging from the outstanding electrochemical performance of batteries with the Mo₂C@CNF/PP separator, the proposal is an enlightening strategy for the advancement high-performance LSBs.