Carbon nanofibers(CNFs)and MnOX@CNF nanocomposites(MCNFs)are fabricated by electrospinning and investigated as free-standing electrodes for supercapacitor.This work presents the effect of heating rate during carbonization on the electrochemical behavior of the as-prepared MCNFs electrodes in 6 mol/L KOH electrolyte.Results show that the MCNFs electrodes carbonized by relatively slower heating rate exhibit higher specific capacitance.The electronic conductivity of the slow heated MCNFs electrodes is better than that of the fast heated electrodes due to the better crystallinity of the MnOXnanoparticles and the graphitic carbon layers forming on the surface of the Mn-loaded CNFs.These MCNFs electrodes demonstrate elevated rate capability and improved cycling performance without adding any polymer binder or electronic conductor.
Lin ShiHaiyong HeYan FangYuying JiaBin LuoLinjie Zhi
In this paper, the bacterial celluloses(BCs) were pyrolysed in nitrogen and then activated by KOH to form a porous three- dimension-network electrode material for supercapacitor applications. Activated pyrolysed bacterial cellulose(APBC) samples with enlarged specific surface area and enhanced specific capacitances were obtained. In order to optimize electrochemical properties, APBC samples with different alkali-to-carbon ratios of 1, 2 and 3 were tested in two electrodes symmetrical capacitors. The optimized APBC sample holds the highest specific capacitance of 241.8 F/g, and the energy density of which is 5 times higher than that of PBC even at a current density of 5 A/g. This work presents a successful practice of preparing electrode material from environment-friendly biomass, bacterial cellulose.
High-quality graphene coating was directly grown on stainless steel meshes via chemical vapor deposition process,during which the morphology of the stainless steel was transformed rugged.When the graphene-coated stainless steel meshes were applied as current collectors of supercapacitors,the changes of the appearance and the graphene coating improved the contact between stainless steel meshes and the active materials,thus benefiting the performance of the supercapacitors.Furthermore,this simple method can be used to prepare the enhanced current collectors for other energy storage devices.
NING JingHAO LongZHANG XianFengLIANG MingHuiZHI LinJie
