Ordered Mesoporous Carbons Loading on Graphene after Different Molten Salt Activations for Supercapacitor Applications

The molten salt activation containing different oxysalts are proposed to activate the ordered mesoporous carbons loading on graphene layers (OMC/G). The effects of different oxysalts activations on the structures of OMC/G are thoroughly investigated by scan electron microscopy (SEM), small angle X-ray scattering (SAXS), Raman spectroscopy and nitrogen adsorption-desorption at 77 K. The structures of these carboneous materials are related with the oxidizing nature of these oxysalts. By using weak oxysalt of K2CO3, the original structure of OMC/G is almost kept together with the appearance of a lot of micropores and mesopores. The electrochemical performances of OMC/G after different oxysalts activation are also studied for supercapacitor applications. OMC/G after weak oxysalt of K2CO3 based electrode results in the highest specific capacitance up to 332.5 F g(-1) at a current density of 1.0 A g(-1), which is higher than those after both KOH activation (276.8 F g(-1)) and the other three oxysalts activation. Moreover, OMC/G-K2CO3 shows an excellent cycling stability with no capacitance loss over 5000 cycles. The molten salt activation would be potentially applied to activate the porous carbons for supercapacitor applications.