N-doped hierarchically porous carbon derived from grape marcs for high-performance supercapacitors

In this report, cost-effective nitrogen (N) -doped porous biocarbon was fabricated from grape marcs, and it demonstrated excellent capacitance, cyclic stability and rate performance as an electrode material for supercapacitors. By using urea as N-doping agent and KOH as activator, the as-prepared carbon material possessed suitable N-doping content (2.04 at%), well-developed porous structure and large specific surface area (2221.4 m(2) g(-1)). As is clearly evidenced by the experimental results, the introduced N-containing functional groups could not only boost the electric double-layer capacitance (EDLC), but endow the material with considerable pseudo-capacitance under acidic conditions, thus resulting in distinct capacitances of the material under different electrolytes (446.0, 345.5 and 310.0 F g(-1) at 0.5 A g(-1) in 1 M H2SO4, 6 M KOH and 1 M Na2SO4, respectively). Moreover, the symmetrical supercapacitor device assembled based on this material also showed excellent performance by reaching an energy density of 16.3 Wh kg(-1) with the power density of 348.3 W kg(-1). All the results ensure that the biomass carbon derived from grape marcs can be used as a low cost, renewable and high-performance electrode material for supercapacitors. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The cost-effective nitrogen (N)-doped porous biocarbon fabricated from grape marcs demonstrated excellent capacitance, cyclic stability, and rate performance for supercapacitors. The material showed distinct capacitances under different electrolytes and assembled supercapacitor device achieved high energy density and power density, indicating its potential as a low-cost, renewable, and high-performance electrode material.