A novel nitrogen/oxygen co-doped carbon sponge (NOCS) is directly applied as a monolithic binder-free electrode for supercapacitors. It exhibits a high specific capacitance and excellent electrochemical cyclability.
The oxygen-containing species in melamine foam carbons are chemically regulated. The optimized carbon anode shows an enhanced potassium-ion storage performance in terms of reversible capacity, rate capability, and long-term cycling stability.
Developing
monolithic electrodes with high capacitor performance
remains a challenge in energy storage field. KOH is applied to chemically
activated commercial melamine sponges, and it can prepare monolithic
N-/O-doped carbon sponge (NOCS) electrodes. The graphitization degree,
heteroatom content, and pore size distribution can be regulated by
adjusting the KOH/melamine sponge mass ratio. The optimal electrode
demonstrates specific capacitances of 440 F g–1 at
1.0 mV s–1 and 273 F g–1 at 0.5
A g–1, and the capacitance retention remains 85.0%
after 10,000 charging–discharging cycles at 10 A g–1. The charge storage mechanism in NOCSs is systematically studied
by separating the capacitive effect (pseudo-capacitance) from the
diffusion-controlled contribution (electrical double-layer capacitance).
Moreover, the capacitance performances of NOCSs in a polyvinyl alcohol/KOH
electrolyte are also investigated by assembling all-solid-state supercapacitors,
which can output an energy density of 5.61 W h kg–1 at 250 W kg–1 and power three light-emitting diodes
with different colors.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.