▎ 摘　　要

NOVELTY - A high dielectric material comprises graphene filler material with core-shell structure and polymer, where polymer is polyvinylidene fluoride. The mass fraction of graphene filler material with core-shell structure is 1-5%, and the mass percentage of polyvinylidene fluoride is 95 to 99%. USE - As high dielectric composite material (claimed) in polymer dielectric composite material field. ADVANTAGE - The material exhibits improved dielectric performance. By selecting proper modified radical of multilayer graphene material for surface treatment, the material improves conductive threshold value of carbon nanotube/polymer high dielectric composite material. The processing method is simple and easy to conduct, causes no environmental pollution, is low cost, has obvious effect, and avoids use of toxic and harmful substances. The material has good mechanical property, corrosion resistance, excellent dielectric property and excellent conductive property. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the high dielectric material involving: taking the multilayer graphene material and adding surface active agent in presence of aqueous strong base solution and conducting hydrothermal treatment for including hydroxyl radical on the surface of multilayer graphene structure; converting hydroxyl modified graphene sheet as crust to form pure graphene filler material with core-shell structure; taking certain amount of graphene nanomaterial with core-shell structure, adding 20% ethanol solvent, dispersing it via ultrasonic treatment for 3 hours, adding polyvinylidene fluoride (PVDF) powder in a certain mass, continuously ultrasonically dispersing for 2 hours, rear grinding the obtained suspension at 70 degrees C to form fine powder; tablet pressing the powder under pressure to form thin sheet; and then setting the sheet at 200 degrees C for 3 hours to obtain material having graphene filling material with core-shell structure and PVDF.