Anion-exchange reaction synthesized CoNi₂S₄ nanowires for superior electrochemical performances

Abstract

In this paper, we report CoNi 2 S 4 nanowire arrays (NWAs) on 3D nickel foams based on an anion-exchange reaction which involved the pseudo Kirkendall effect. Due to the low electronegativity of sulfur, CoNi 2 S 4 NWAs exhibit higher conductivity compared with Ni-Co oxide NWAs when used as active materials in supercapacitors. The electrochemistry tests show that these self-supported electrodes are able to deliver ultrahigh specific capacitance (1250 F g À1 at a current density of 5 mA cm À2 ), together with a considerable areal capacitance (2.5 F cm À2 at a current density of 5 mA cm À2 ), Furthermore, a capacitance retention of 72% after 5000 charge-discharge cycles at 5 mA cm À2 is obtained, indicating the excellent cycling stability of the CoNi 2 S 4 NWA/nickel foam electrode. The superior electrochemistry capacity demonstrates that CoNi 2 S 4 NWAs are promising electrode materials for supercapacitor applications.Scheme 1 Schematic illustration of the fabrication process for Ni-Co sulfide nanowire arrays.This journal is

Synergistically Active NiCo2S4 Nanoparticles Coupled with Holey Defect Graphene Hydrogel for High‐Performance Solid‐State Supercapacitors

“…Figure c shows the plot of the GCD curve of NiCo 2 S 4 @HGH. The distinct plateau regions in the GCD curve demonstrate the pseudocapacitive behavior, caused by the charge‐transfer reaction and electrochemical adsorption/desorption process at the electrode/electrolyte interface, which is consistent with the redox peaks in the CV curve . The GCD curve of NiCo 2 S 4 @HGH is nearly symmetrical, without a significant IR drop at low current densities, indicating a rapid I – V response and an excellent electrochemical reversibility.…”

“…Figure 4c shows the plot of the GCD curve of NiCo 2 S 4 @HGH.T he distinct plateau regions in the GCD curve demonstrate the pseudocapacitive behavior,c aused by the charge-transfer reaction and electrochemical adsorption/de- www.chemeurj.org sorptionp rocess at the electrode/electrolyte interface,w hich is consistentw ith the redox peaks in the CV curve. [23] The GCD curve of NiCo 2 S 4 @HGH is nearly symmetrical, without as ignificant IR drop at low current densities, indicating ar apid I-V response and an excellent electrochemical reversibility.B ased on the GCD curve, the C s of NiCo 2 S 4 @HGH were calculatedt ob e 1000, 961, 886, 883, and 801 Fg À1 at the currentd ensities of 0.75, 1.5, 3, 5, and 6Ag À1 ,r espectively.F igure 4d showsaplot of C s as afunction of current density.Apparently,asthe current density increases, the C s decreases steadily with small variation. At ah igh current density of 6Ag À1 ,t he NiCo 2 S 4 @HGH maintained 80.1 %o fi ts initial capacitance, 1000 Fg À1 .T his remarkable rate capability of NiCo 2 S 4 @HGH was attributed to the synergistic effect between nickela nd cobalt with their inherent richer oxidations tates.I na ddition, the integration of NiCo 2 S 4 in the HGH was vital in maintaining the rate capability,a st he electrode was prepared without adding any binder or conducting agent.…”

Rapid synthesis of bismuth molybdate nanoplates for supercapacitor applications by microwave combustion

“…As of late, the discerning structure of nanosheets [6], [9], [10] nanowire [3], [11] and nanorod [4], [12] has been considered as an incredible accomplishment in electrochemical (EC) research.…”

Mixed Metal Sulfides for Electrochemical Energy Storage and Conversion

“…To avoid the "dead surface" and fully utilize electroactive materials, nanostructured nickel cobalt sulfides with various nanoarchitectures such as nanotubes, [30,112,[159][160][161] nanowires, [162] nanoneedles, [119] and nanosheets [66,111,117,[163][164][165][166][167][168][169][170][171][172] [108] Copyright 2013, Royal Society of Chemistry. Panels (c-e): Reproduced with permission.…”