Comparison of surface and bulk nitrogen modification in highly porous carbon for enhanced supercapacitors

Biomass-derived nanostructured porous carbons for lithium-sulfur batteries

“…Since the carbon is non-polar whereas Li polysulfides are inherently polar molecules, the cathodes which make up this non-polar host still face fast capacity decay over long-term cycling because it can only permit adsorption of polysulfides up to diffusion limitations [71,72]. Surface properties of the porous carbon can be altered by functionalization such as doping with N or B. Doping carbon with N or B is an effective way to enhance the intrinsic properties of porous carbon materials as it may facilitate the chemisorption of Li polysulfides at the surface [16,[73][74][75][76]. By considering the fact that N-doping can improve the performance of Li-S batteries, Yu et al [77] synthesized an inherently N-doped microporous carbon from human hair by carbonization and NaOH activation at 900°C (Fig.…”

“…In addition, based on the reports that N-doping could further improve the electrochemical properties via enhanced surface affinity to Li polysulfides [16,73,74,76], Qu et al [89] synthesized ordered N-rich mesoporous carbon by pyrolysis of gelatin (biomass waste) as a carbon source and SBA-15 as hard template. The N-rich mesoporous carbon was activated with KOH and the surface area increased to 2892.6 m 2 g −1 with a pore volume of 2.80 cm 3 g −1 .…”

Fabrication of hybrid Co3O4/NiCo2O4 nanosheets sandwiched by nanoneedles for high-performance supercapacitors using a novel electrochemical ion exchange

“…Despite these advantages, its relatively low energy density must be increased to satisfy their practical applications. Compared with conventional carbon materials featured with high conductivity and low electric double layer capacitance [1, [7][8][9], the transition metal oxides/hydroxides (such as RuO 2 , Co 3 O 4 , NiO, MnO 2 and Ni(OH) 2 ) present high pseudocapacitance through redox reactions taking place at the interface of electrode/electrolyte, which can enhance the energy density of device [10][11][12][13][14]. Among these electroactive materials, Co 3 O 4 has dominated over other materials due to its low cost, simple synthetic process and extremely high theoretical capacitance (~3560 F g -1 ) [15,16].…”

Recent advances and challenges of stretchable supercapacitors based on carbon materials

“…In EDLCs, the electrode surface area plays a crucial role in the performance of a capacitor, which can provide higher power densities, fast charge-discharge processes, excellent cycling stabilities, but inferior energy densities. Carbon materials with large specific surface areas and excellent conductivity, such as activated carbon [39,40], carbon nanofibers [41,42], mesoporous carbon [43,44], carbon nanotubes (CNTs) [45,46], graphene [47,48], and carbide-derived carbon [49,50], have been widely employed in EDLCs. While in PCs, composite materials composed of carbon nanomaterials together with electrically conductive polymers (e.g., polyaniline (PANI) [51][52][53][54], polypyrrole (PPy) [55][56][57][58], and poly[3,4-ethylenedioxythiophene] (PEDOT) [59]) or transition metal oxides (e.g., MnO 2 [60,61], NiO [62,63], RuO 2 [64,65], VO x [66][67][68], and TiO 2 [69,70] ) have been widely used for the electrodes.…”