Three-dimensional N/S Co-doped holey graphene oxide based hydrogel electrodes for high performance supercapacitors

Large specific surface area, conductivity and doping are necessary to design high performance supercapacitor electrode materials. Nevertheless, the traditional graphene as electrode materials is unable to achieve superior electrochemical performance. Here we prepared a three-dimensional N-and S co-doped holey graphene hydrogel (N/S-HGH) to achieve an optimized pore structure with a high conductivity, effective electron and ion transfer pathways. The binder-free N/S-HGH electrode delivers a gravimetric capacitance of 346 F g(-1) with a volumetric capacitance of 242 F cm(-3) and retains 93.8% of the original capacitance after 10000 cycles at 10 A g(-1). Moreover, the supercapacitor fabricated from N/S-HGH deliver gravimetric and volumetric energy density of 24.6Wh kg(-1) and 17.2 Wh L-1 respectively, at a power density of 415.4W kg(-1) (290.8 W L-1), displaying enormous prospect for practical applications.