Fabrication of Porous β-Co(OH)₂ Architecture at Room Temperature: A High Performance Supercapacitor

Abstract

A facile, cost-effective, surfactant-free chemical route has been demonstrated for the fabrication of porous β-Co(OH)2 hierarchical nanostructure in gram level simply by adopting cobalt acetate as a precursor salt and ethanolamine as a hydrolyzing agent at room temperature. A couple of different morphologies of β-Co(OH)2 have been distinctly identified by varying the mole ratio of the precursor and hydrolyzing agent. The cyclic voltammetry measurements on β-Co(OH)2 displayed significantly high capacitance. The specific capacitance obtained from charge-discharge measurements made at a discharge current of 1 A/g is 416 F/g for the Co(OH)2 sample obtained at room temperature. The charge-discharge stability measurements indicate retention of specific capacitance about 93% after 500 continuous charge-discharge cycles at a current density of 1 A g(-1). The capacitive behavior of the other synthesized morphology was also accounted. The nanoflower-shaped porous β-Co(OH)2 with a characteristic three-dimensional architecture accompanied highest pore volume which made it promising electrode material for supercapacitor application. The porous nanostructures accompanied by high surface area facilitates the contact and transport of electrolyte, providing longer electron pathways and therefore giving rise to highest capacitance in nanoflower morphology. From a broad view, this study reveals a low-temperature synthetic route of β-Co(OH)2 of various morphologies, qualifying it as supercapacitor electrode material.

Facile synthesis of nickel–cobalt double hydroxide nanosheets with high rate capability for application in supercapacitor

“…As shown in the obtained results (Fig. S2), all the cobalt and nickel ions before and after oxidation can be identified as divalent ions (Zhuo and Ge 2009;Lee et al 2011;Mondal et al 2013;Deki and Hosokawa 2013), indicating that no oxidation of metal ions occurs. In the FTIR spectra (Fig.…”

“…The electrochemical tests on the electrodes including cyclic voltammetry (CV) and galvanostatic charge-discharge measurements were performed in a 3 mol L -1 KOH aqueous solution. The calculation about the specific capacitance was based on the active material in electrodes as described in the literatures (Mondal et al 2013;Chen et al 2013). The composition of as-prepared Ni x Co 1-x LDH was determined by a chemical titration method according to the work of Liang et al (2010).…”

O/W interface-assisted hydrothermal synthesis of NiCo2S4 hollow spheres for high-performance supercapacitors

“…With the increase of scan rate, the anodic and cathodic peaks shifted, which is mainly due to the ohmic resistance and polarization because of the diffusion of electrolyte ions in the porous electrode during the redox reactions [33]. The specific capacitances were calculated according to Eq.…”

Highly flexible conductive fabrics with hierarchically nanostructured amorphous nickel tungsten tetraoxide for enhanced electrochemical energy storage

“…In contrast, pseudocapacitors can store more energy than EDLCs because of the fast Faradic charge transfer reactions occurring between the electroactive material and the electrolyte solution [17]. Therefore, intensive research efforts have been devoted to the fabrication of nanostructured single and mixed metal oxides/hydroxide electroactive materials with tailored morphologies to increase the energy storage abilities for pseudocapacitors [18][19][20][21][22]. During the electrode preparation for pseudocapacitors, mixing of polymer binders and conductive agents with electroactive materials causes an increase in the dead surface.…”