Carbon Electrode Material Of Super Capacitor

This paper focused on the characteristics and potential in the super capacitorelectrode of grapheme made with reduction methods. In this research, anenvironmentally friendly, highly efficient, low cost and high performance of Grapheneelectrode preparation method was tried to find. As a comparison also studied theactivated carbon materialsand carbon nanotube electrode electrochemical performance.In this study, activated carbon was prepared by using walnut shells and the localanthracite coal in Chengdu, as precursors respectively. Tests showed that: they are bothideal materials for preparation of activated carbon, which made of them have superiorelectrochemical performance. The walnut shell based activated carbon in5.5mol/LKOH solution, its specific capacitance was298F/g when the scanning rate was10mV/sand338F/g when the current density was1A/g. From this, the walnut shell basedactivated carbon is an ideal electrode materials for supercapacitors.Carbon nanotubes, having different morphology, had been directly grown innickel net by hot CVD law after acetone and acetylene as precursor been respectivelyselected, then they are tested as electrode of super capacitor. The results indicated that:carbon nanotube electrodes prepared by using acetylene as precursor, had betterelectrochemical performance obviously than using acetone. The specific capacitancewas118F/g when current density was1A/g, but there was also a gap between this resultand our expectations. The main reason was that the space among the tubes in carbonnanotube was so disconnected that interior space cannot be used and double electrodelayer can only be formed on the ektexine from electrolyte, leading to an effectivespecific surface area and specific capacitance were both small.Graphene in this research was prepared through this way: first of all, oxidationgraphite containing rich functional groups were obtained through Hummers and theimproved way for preparation of oxidation graphite respectively; after that, graphene ofdifferent morphology were prepared using hydration hydrazine restore、 fast hot restoreand microwave expansion method respectively. The results indicated that: the graphenewas so easily gathered in the hydration hydrazine restore process that it can not be applied as the electrode material for super capacitor; grapheme electrode, prepared byfast hot restore, performed the nature of fake capacitance in electrochemical test, whichwas not hoped for, and the stability had to be raised; meanwhile, by microwaveexpansion, better Graphene can only be achieved by expanding acidic graphite oxide,and electrodes made of it showed good electrochemical performance: specificcapacitance was222F/g when scanning speed was5mV/s. It had the characteristics ofsimple preparation, environmental protection, high efficiency, so that it had good marketprospects.