High-throughput fabrication of porous carbon by chemical foaming strategy for high performance supercapacitor.

Highlights • A gas foaming strategy is adopted to prepare the 3D hierarchical porous carbon. • NaHCO 3 is used as activator based on its multistep pyrolysis process. • The HPC shows high specific capacitance and outstanding stability. Abstract Inspired by people to make flour food, a one-pot, low-cost, green and environmental friendly gas foaming strategy is adopted here to prepare the three-dimensional hierarchical porous carbon (HPC) by introducing NaHCO 3 as foaming and activation agent. During the pyrolysis process, the CO 2 gas produced during the transforms from NaHCO 3 into Na 2 CO 3 will resulted in the producers of the macro-pores and meso-pores, meanwhile, the as-produced Na 2 CO 3 further reactor with the carbon intermediate at a high temperature, and finally result in forming a micro-pores porous structure. Such intimate structural interconnectivities provide three-dimensional continuous pathway for electron rapid transfer and the interconnected pores allow for the ion to penetrate and evenly contact the electrode material quickly. The electrochemical performance of HPC exhibits a high specific capacitance of 350 F g−1 at 1 A g−1 and outstanding electrochemical stability with capacitance retention up to 97% after 10,000 cycles. Moreover, the as-assembled symmetric supercapacitor exhibits an ultrahigh energy density of 27.4 Wh kg−1, much higher than most of carbon-based supercapacitors. These results demonstrate a straightforward environment friendly method to mass-produce economical, robust carbon materials as promising candidates for supercapacitor application. [ABSTRACT FROM AUTHOR]