Ultrafast Self-Assembly of Graphene Oxide-Induced Monolithic NiCo-Carbonate Hydroxide Nanowire Architectures with a Superior Volumetric Capacitance for Supercapacitors

The monolithic electrodes with high volumetric capacitance demonstrate a great potential in practical industrial applications for supercapacitors. Herein, a novel strategy for ultrafast self-assembly of graphene oxides (GO)-induced monolithic NiCo-carbonate hydroxide (NiCo-CH) nanowire composite films (G-CH) is reported. The oxygen-containing functional groups on the GO surface help effectively to induce formation of the monodisperse NiCo-CH nanowires. Such a nanowire-shaped structure further functions as a scaffold and/or support, leading to 25 s of ultrafast self-assembly for G-CH composite films and a relatively loose and open channel that contributes to fast electrolyte transport. The as-obtained monolithic G-CH architectures show an excellent supercapacitor performance as binder-and conductive agent-free electrode, evidenced by a superior volumetric capacitance of 2936 F cm(-3) and good electrochemical stability. Combining highly conductive carbon nanotubes (CNTs) into the monolithic composite films can further create well-interconnected conductive networks within the electrode matrix, thus to improve the reaction kinetics and rate capability. The present strategy that can modulate the growth of the high-electroactive pseudocapacitive hydroxides and achieve an ultrafast self-assembly of monolithic composites may pave a promising new way for development of high-performance supercapacitors and shed a new light on the configuration of carbon-based electrode materials in energy storage and conversion devices.