Three-dimensional honeycomb-like porous carbon strutted nickel phosphide grown by analogous gel blowing for aqueous asymmetric supercapacitor

摘要

Hierarchically porous structures are attracting marvelous concern in energy storage system, due to their excellent electrons and ions transport properties that spring from the high-pitched surface area and opulent porosity. However, the existing scientific methods for synthesizing hierarchically porous materials usually require a template-assisted procedure, which is elaborate, time consuming and not attainable for mass production. Herein, a nickel nitrate assisted polymer (polyvinyl pyrrolidone) in-situ 'gel-blowing' pyrolysis and subsequent low-temperature phosphorylation method is used to prepare porous carbon strutted nickel phosphide nanoparticles. As an anode material for supercapacitors, it contributes a high specific capacity of 116 mA h g(-1) at 1 A g(-1) in 2 M KOH aqueous electrolyte. To highlight, a novel aqueous asymmetric supercapacitor depended on the porous carbon strutted nickel phosphide nanoparticles and activated honeycomb-like porous carbon electrodes is assembled, achieving a large working voltage of 1.70 V, which delivers high energy density of 32 Wh kg(-1) at a high power density of 907 W kg(-1). What's more, it possesses exceptional cycling stability with 98% capacity preservation after 8000 cycles. The results suggest great potential in developing new families of the integrated and robust metallic compounds self-decorated porous carbon nanomaterials.