A multi-functional CoN-Mo2N heterostructure nanorods for high performance lithium-sulfur batteries

A single functional material can hardly simultaneously overcome the problems of poor conductivity of active sulfur, shuttle effect and slow redox reaction kinetics of lithium polysulfides (LiPSs) in rechargeable lithium-sulfur batteries. Herein, a multi-functional CoN-Mo2N heterostructure nanorods with excellent adsorption capability and bidirectional catalytic ability is introduced. It is found that the CoN-Mo2N heterostructure has a significant interaction with LiPSs, and its chemical affinity can promote the adsorption of LiPSs; The Li2S nucleation and electrochemical testing results show that the CoN-Mo2N heterostructure can promote the uniform nucleation and rapid growth of Li2S, where CoN tends to promote the oxidation reaction kinetics, and Mo2N promotes the reduction reaction kinetics. The assembled Li-S cells with CoN-Mo2N modified separators can deliver outstanding rate performance and long-cycling stability, with a high initial reversible discharge capacity of 1605.8 mAh g−1 at 0.1C, and capacity decay rate per cycle of 0.198 % after 200 cycles at 0.2C.