MoS2 wrapped MOFs-derived N-doped carbon nanorods as an effective sulfur host for high-performance lithium-sulfur batteries

Abstract It is a great challenge to develop the cathode materials with high efficiency, long life and low-cost for lithium-sulfur batteries. In this paper, we design a simple hydrothermal method to synthesize MoS2 wrapped the MOFs-derived N-doped carbon nanorods as an effective sulfur host to improve the electrochemical performance of lithium-sulfur batteries. In the hydrothermal process, the cubic zeolitic imidazolate framework-67 (ZIF67) particles are connected together to form nanorods, and MoS2 nanosheets are wrapped on the surface of the nanorods. In this composite, the carbon nanorods derived from ZIF67 is the main host for S-loading, while N-doping can change the hybrid orbital form of carbon and significantly improve the chemical adsorption of polysulfide. The elemental cobalt and cobalt oxide derived from ZIF67 can improve the electronic conductivity and polarity of the composite. And MoS2 coating layer can provide more active sites, accelerate the sulfur redox reactions and effectively restrain the shuttle effect. The synergetic effects of above-mentioned factors make the MoS2@CZIF67/S composite cathode material shows excellent electrochemical performance. The composite shows high reversible specific capacities of 1391.9 and 806.1 mAh g−1 at 0.1C and 1C rate, respectively, and exhibits a capacity retention of 70.5% after 400 cycles at 1C rate.