Lamellar-structured biomass-derived phosphorus- and nitrogen-co-doped porous carbon for high-performance supercapacitors

As electrical energy storage and delivery devices, carbon-based supercapacitors have attracted much attention for advancing the energy-efficient economy. It is important to develop a facile, low-cost and environmentally friendly method of producing novel carbon materials. In this study, we report a scalable synthesis of phosphorus- and nitrogen-co-doped porous carbons using lamellar-structured fish scale. The special lamellar structure of fish scale allows the production of porous carbons with large specific surface areas (up to 1300 m² g^-1) and a high level of mesoporosity. Their inherent organic composition could be adapted with abundant N and P functional groups on the final carbons. Their high levels of porosity and rich surface functionality permit the carbons to exhibit excellent electrochemical performance as electrode materials for supercapacitors. The energy densities of supercapacitors approach 11.7 and 33.1 W h kg^-1 in aqueous and IL electrolytes, respectively.