Nitrogen Doping Improves the Immobilization and Catalytic Effects of Co9S8in Li-S Batteries

Several critical issues, such as the shuttling effect and the sluggish reaction kinetics, exist in the design of high-performance lithium-sulfur (Li-S) batteries. Here, it is reported that nitrogen doping can simultaneously and significantly improve both the immobilization and catalyzation effects of Co(9)S(8)nanoparticles in Li-S batteries. Combining the theoretical calculations with experimental investigations, it is revealed that nitrogen atoms can increase the binding energies between LiPSs and Co9S8, and as well as alleviate the sluggish kinetics of Li-S chemistry in the Li(2)S(6)cathode. The same effects are also observed when adding N-Co(9)S(8)nanoparticles into the commercial Li2S cathode (which has various intrinsic advantages, but unfortunately a high overpotential). A remarkable improvement in the battery performances in both cases is observed. The work brings heteroatom-doped Co(9)S(8)to the attention of designing high-performance Li-S batteries. A fundamental understanding of the inhibition of LiPSs shuttle and the catalytic effect of Li2S in the newly developed system may encourage more effort along this interesting direction.