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Key Words:HIGH-PERFORMANCE; HIGH-POWER; NANOSHEETS; GRAPHENE; COMPOSITES; ELECTRODES; MICROSPHERES; NANOTUBES; BEHAVIOR; BATTERY

Abstract:MnO2 has been considered as a very promising positive electrode candidate for high energy density asymmetric supercapacitors (ASCs) because of high theoretical capacitance. However, the electro-chemical performance of pure MnO2 for ASCs has still been severely limited by poor electronic conductivity, volume expansion and dissolution problem. Herein, we report flower-like MnO2-carbon composite (MnO2/SHAC) as positive electrode and layered Sisal Hemp Active Carbon (SHAC) as negative electrode for high-energy ASCs. The flower-like MnO2/SHAC positive electrode comprised a number of interconnected thin nano-flakes with a length of about 50-100 nm and a thickness of about 10 nm and exhibited a large specific surface area of 189.6 m(2) g(-1) and good conductivity. The SHAC negative electrode showed multi-layered graphene-like structure and a high BET surface area of 1303.5 m(2) g(-1). Moreover, the assembled MnO2/SHAC//SHAC ASC exhibits a maximum energy density of 46.2 Wh kg(-1) at 0.1 A g(-1) and a maximum power density of 3679.5 W kg(-1) at 6 A g(-1), suggesting that MnO2/SHAC composite has promising potential for practical supercapacitors with enhanced energy. (C) 2020 Elsevier B.V. All rights reserved.

Volume:826

Translation or Not:no