Ultrahigh power graphene based supercapacitor

Supercapacitor as a type of new energy storage device has important applications in the development of smart electronics and vehicles, which can provide a high current density to drive the devices. Recently, although graphene has been considered as a very promising electrode material for supercapacitors, the poor control of the dispersion of graphene and the limited way of electrode preparation process severely hinder its power performance. Here, we report a supercapacitor technology with ultrahigh power combining the electrochemically reduced graphene oxide deposited on nickel nanocone array with printed ethylene vinyl acetate cofferdams. The supercapacitor showed excellent rate performance, ultrahigh power density (1230 mWh/cm³) and high ionic mobility, especially when compared to those with separator. In light of the simple process (electrochemical-deposition and stencil printing, etc.), this technology can meet the demand of applications with high power density and inspire the development of other energy storages to achieve better performance.