▎ 摘　　要

NOVELTY - Preparing nickel diselenide-graphene composite material comprises (i) adding graphene oxide to 30 ml de-ionized water, adding reducing agent, stirring with ultrasound until the dispersion is uniform, adding selenium-containing substance and nickel-containing inorganic salt, and performing ultrasonic dispersion, (ii) placing mixed solution into a hydrothermal synthesis kettle, and maintaining the temperature at 140-180 degrees C for 5-15 hours, and (iii) after cooling reaction, separating product in hydrothermal synthesis kettle by suction filtration, washing with de-ionized water, and freeze drying. USE - The method is useful in sodium ion battery (claimed). ADVANTAGE - The method: has good cycle stability and rate characteristics.