Effect of self-doped heteroatoms on the performance of biomass-derived carbon for supercapacitor applications

Biomass-derived carbon materials with unique electronic, chemical, and surface properties have become a research hotspot in energy storage applications. However, these activated carbon materials cannot meet the emerging demand for high energy/power densities in the recent era. On the other hand, heteroatom doped carbon materials as supercapacitor electrodes have demonstrated enhanced conductivity, surface wettability and induced pseudocapacitance effect thereby delivering improved energy/power densities with versatile properties. Unlike external doping techniques, self-doping of heteroatoms doesn't involve additional processing steps and/or use of harmful chemicals. While review papers on the post-doping/in-situ doping of biomass carbon using external dopants are available in literature, comprehensive reports on self-doped carbon for supercapacitor has received scant attention. This review article focuses on the state of art update on recent developments in the field of self-doped biomass-derived carbon materials as a supercapacitor electrode. With the discussion on the effect of heteroatom doping species, a progressive development in the single-/dual-/multi-heteroatom doped porous carbon and its electrochemical performance covering the specific capacitance, cyclic life and energy/power densities is explored. Finally, the challenges in the self-doped carbon materials and its future perspectives is highlighted to provide a key insight to the promising factors for future developments of supercapacitor electrodes.