▎ 摘　　要

NOVELTY - Nickel(II) hydroxide-graphene composite material, comprises large-area nickel(II) hydroxide nanosheet laid flat on the surface of the multilayer graphene, where the thickness of the nanosheet is less than 5 nm. USE - The composite material is useful for electrode materials of high-rate and flexible supercapacitor. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the nickel(II) hydroxide-graphene composite material, comprising (i) taking N,N-dimethylformamide and distilled water in a volume ratio of 2:2, (ii) adding expanded graphite and reacting by ultrasonic vibration to obtain multilayer graphene solution, and then adding distilled water to make the ratio of N,N-dimethylformamide to distilled water reach 2:8, where the concentration of each additive is calculated based on the total volume of all added N,N-dimethylformamide and water, and the concentration of multilayer graphene is 2 mg/ml, (iii) adding urea and nickel chloride hexahydrate to the multilayer graphene solution, where the mass concentration of urea is 3-4 mg/ml and the mass concentration of nickel chloride hexahydrate is 3-5 mg/ml, stirring the obtained mixed solution, pouring into hydrothermal reactor, reacting at 150 degrees C for 2 hours, and then cooling to room temperature, and (iv) taking out the product, washing with alcohol, then centrifugally washing with water, and drying the washed product in a drying cabinet at 60 degrees C for 24 hours to obtain final product.