With the increasingly severe environmental problems and the rapid development of electronic and electric equipment, it is imperative to design and develop efficient energy storage equipment. Lithium-sulfur batteries are considered to be one of the most promising energy storage systems of the next generation due to their high energy density, high theoretical capacity, abundant sulfur cathode resources, low price and environmental friendliness. However, due to the poor conductivity of the sulfur cathode material and its discharge product, lithium sulfide, the volume effect and the "shuttle effect" during the charging and discharging process, the utilization rate of sulfur in the battery is low, the capacity decays quickly, and the rate performance is poor, which seriously hinders The commercialization of lithium-sulfur batteries.

　　In response to these problems, the research group of Professor Xu Maowen designed and synthesized a double-layer core-shell NiO-NiCo2O4 heterojunction C hollow nanocage as a sulfur carrier, and it was first used in lithium-sulfur batteries. This hollow structure can not only provide sufficient space for sulfur storage, but also effectively deal with the volume effect during sulfur charging and discharging; in addition, the NiO-NiCo2O4 heterojunction nanocage can take advantage of its unique composition to effectively inhibit polysulfide Substances dissolve and diffuse and promote the kinetic process in the conversion reaction, alleviate the shuttle effect of the battery, and fully reflect the advantages of heterojunction. Based on this unique design, the material is used as the positive electrode of a lithium-sulfur battery, showing a high specific capacity and good cycle stability.

　　The research work was funded by the National Natural Science Foundation of China and the Basic Operating Expenses Project of Central Universities and was completed in cooperation with Dr. Chen Yuming of Massachusetts Institute of Technology.