Ultrahigh Specific Capacitances for Supercapacitors Achieved by Nickel Cobaltite/Carbon Aerogel Composites

Abstract

Nickel cobaltite, a low cost and an environmentally friendly supercapacitive material, is deposited as a thin nanostructure of 3–5 nm nanocrystals into carbon aerogels, a mesoporous host template of high specific surface areas and high electric conductivities, with a two‐step wet chemistry process. This nickel cobaltite/carbon aerogel composite shows ultrahigh specific capacitances of around 1700 F g−1 at a scan rate of 25 mV s−1 within a potential window of −0.05 to 0.5 V in 1 M NaOH solutions. The composite also possesses an excellent high rate capability manifested by maintaining specific capacitances above 800 F g−1 at a high scan rate of 500 mV s−1, and an outstanding cycling stability demonstrated by a negligible 2.4% decay in specific capacitances after 2000 cycles. The success is attributable to the fuller utilization of nickel cobaltite for pseudocapacitance generation, made possible by the composite structure enabling well exposed nickel cobaltite to the electrolyte and easy transport of charge carriers, ions, and electrons, within the composite electrode.

Mesoporous composite nickel cobalt oxide/graphene oxide synthesized via a template-assistant co-precipitation route as electrode material for supercapacitors

“…6a) conducted in a potential window between À0.15 and 0.35 V are 1273.10, 1211.25, 1178 F g À1 at 0.5, 1, 2 A g À1 , higher than those achieved by NiCo 2 O 4 shown in Fig. S2a fabricated with the same coprecipitation method, corresponding to the following equation: [39] where Cm refers to the specific capacitance, I is the current, m denotes the loading mass, Dt represents the discharge time, DU is potential window. In the magnified inset, the NCG-10 still remains high capacitance of 772.5 and 687 F g À1 at large current densities of 5 and 10 A g À1 .…”

Three dimensional architectures: design, assembly and application in electrochemical capacitors

“…19d) Carbon aerogels (CA) are also a superior candidate for highly conductive porous matrix, which own a 3D well-connected through-pore structure. [161][162][163][164][165][166][167] These hierarchical carbon aerogels are always obtained from pyrolysis of polymer materials. As an example, Gutierrez et al 168 recently reported 3D carbon aerogels with hierarchical pores from PPO-PEO-PPO block copolymer.…”

Influence of Nitrogen moieties on CO2capture of Carbon Aerogel

“…The morphology and microstructure of the samples were studied using SEM; the results are shown in pores; it has high porosity in the range of 80-90%, stable mesopores with sizes ranging from 2-50 nm, and a large specific surface area [27][28][29][30][31][32]. Two different approaches have been adopted to improve the CO 2 adsorption capacities of porous carbons.…”