▎ 摘　　要

NOVELTY - A supercapacitor consists of positive electrode sheet, negative electrode sheet, separator interposed between positive electrode sheet and negative electrode sheet and aqueous electrolyte solution having ion conductivity. The positive electrode sheet comprises positive electrode sheet current collector and a positive electrode material mixture deposited on surface of positive electrode sheet current collector and negative electrode sheet comprises negative electrode sheet current collector and negative electrode material mixture deposited on surface of negative electrode sheet current collector. The positive electrode mixture comprises manganese oxide/graphene composite material and negative electrode mixture comprises negative electrode active material. USE - Supercapacitor. ADVANTAGE - The supercapacitor has excellent cycle life and is economical. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of supercapacitor, which involves using 98% sulfuric acid, potassium permanganate, deionized water and hydrogen peroxide, hydrochloric acid solution, barium chloride, graphite oxide, manganese acetate and obtaining manganese oxide/graphene composite material and preparing positive electrode sheet and negative electrode sheet.