(NiCo) Se/(NiCo) Se2-coated C heterostructure composite material and preparation method and application thereof

The invention discloses a (NiCo) Se/(NiCo) Se2 (at) C heterostructure composite material and a preparation method and application thereof, nickel salt and cobalt salt are added into a mixed solution of glycerol and isopropanol to obtain a precursor, the precursor and selenium powder are uniformly mixed and then annealed, and (NiCo) Se2 is prepared. The preparation method comprises the following steps: ultrasonically dispersing (NiCo) Se2 into an organic matter solution, violently stirring to obtain a (NiCo) Se2 (at) orgonic composite material, uniformly mixing the (NiCo) Se2 (at) orgonic composite material with selenium powder for the second time, and annealing to obtain the (NiCo) Se/(NiCo) Se2 (at) C heterostructure composite material. The heterostructure material obtained by the method has good structural continuity and controllability, and the product is low in cost, environment-friendly and good in reproducibility. The material is applied to a sodium ion battery, shows relatively high specific discharge