Monodisperse Molybdenum Nanoparticles as Highly Efficient Electrocatalysts for Li-S Batteries

Lithium-sulfur (Li-S) batteries have attracted widespread attention due to their high theoretical energy density. However, their practical application is still hindered by the shuttle effect and the sluggish conversion of lithium polysulfides (LiPSs). Herein, monodisperse molybdenum (Mo) nanoparticles embedded onto nitrogen-doped graphene (Mo@N-G) were developed and used as a highly efficient electrocatalyst to enhance LiPS conversion. The weight ratio of the electrocatalyst in the catalyst/sulfur cathode is only 9%. The unfilled d orbitals of oxidized Mo can attract the electrons of LiPS anions and form Mo-S bonds during the electrochemical process, thus facilitating fast conversion of LiPSs. Li-S batteries based on the Mo@N-G/S cathode can exhibit excellent rate performance, large capacity, and superior cycling stability. Moreover, Mo@N-G also plays an important role in room-temperature quasi-solid-state Li-S batteries. These interesting findings suggest the great potential of Mo nanoparticles in building high-performance Li-S batteries.

Automated summary

A highly efficient electrocatalyst, consisting of monodisperse molybdenum nanoparticles embedded onto nitrogen-doped graphene, was developed to enhance lithium polysulfide conversion in lithium-sulfur batteries. The electrocatalyst facilitates fast conversion of LiPSs by attracting electrons of LiPS anions. Batteries based on this new cathode showed excellent performance and stability, suggesting the great potential of molybdenum nanoparticles in high-performance Li-S batteries.