Fabrication of a 3D MnO2/graphene hydrogel for high-performance asymmetric supercapacitors

摘要: A three-dimensional hydrogel of graphene and MnO2 nanoparticles has been prepared by a two-step synthesis. At first, were grown onto both surfaces nanosheets oxide with the aid benzyl alcohol in an aqueous suspension, then composite reduced (rGO) was reduction-induced situ self-assembly. Then, asymmetric supercapacitors high energy power densities fabricated using MnO2/rGO as positive electrode pure rGO negative neutral Na2SO4 (1.0 M) electrolyte. The supercapacitor exhibited performance density 21.2 W h kg−1 0.82 kW kg−1, it can be cycled reversibly wide potential window 1.6 V (0–1.6 V). also stable cycling 89.6% capacitance after 1000 cycles. This work provides new method for preparation metal oxide/graphene hydrogel-based free polymer binders conducting additives.