▎ 摘　　要

NOVELTY - Preparing composite film of carbon base supported manganese dioxide nanosheet involves using two dimensional graphene oxide and one-dimension carbon nanom tube as carbon base, growing two-dimensional manganese dioxide nano sheet on surface, acidifying with nitric acid to prepare carbon nano-tube by Hummer method of graphene oxide, adding 5 plus minus 1 mg surface-modified carbon nano-tube and 5 plus minus 1 mg graphene oxide, adding into 158 plus minus 2 mg potassium permanganate and 50-1420 plus minus 0.5 mg sodium sulfate in 0.5 mL de-ionized water and dispersing ultrasonically for 5-10 degrees C then transferring solution into hydrothermal kettle, keeping for 10 plus minus 150 at 30 plus minus 1 degrees C, washing with de-ionized water and ethanol for multiple times, drying to obtain precursor under protection of argon gas to 200 plus minus 1 degrees C. USE - Method for preparing composite film of carbon base supported manganese dioxide nano sheet used as cathode material of lithium ion battery(claimed). ADVANTAGE - The method enables to prepare composite film of carbon base supported manganese dioxide nanosheet has excellent electrical properties. DETAILED DESCRIPTION - Annealing for 4 plus minus 0.1 hours to obtain oxidized graphene, preparing graphene by hydrazine hydrate reduction of composite material and mixing into de-ionized water, marking as first solution, mixing little pure graphene into de-ionized water and marking as second, mixing first and second solution followed by vacuum filtration to obtain black three-layer composite film, where lower layer has little graphene, middle layer is grown with manganese dioxide and oxidized graphene and mixed layer of carbon nano-tube composite material, freezing and drying to obtain black film and performing for 12 plus minus 2 hours to obtain flexible composite film of three-dimensional multi-hole structure.