Hierarchical Cu₂S@NiCo-LDH double-shelled nanotube arrays with enhanced electrochemical performance for hybrid supercapacitors

Abstract

Hierarchical nanotube arrays with complex shell structures are attractive for applications in electrode materials for effectively boosted electrochemical performance, but the construction of such delicate architectures with excellent electrochemical performance...

Influence of Transition Metals (Cu and Co) on the Carbon-Coated Nickel Sulfide Used as Positive Electrode Material in Hybrid Supercapacitor Device

“…The fitted data demonstrated Warburg resistance of the NSC and NCuSC electrodes were almost same and decreased in the NCoSC electrode. The lower W o value of the NCoSC electrode signified facile and shorter ion diffusion path to the active electrode material with more ideal capacitive behavior compared to the other two electrodes [2][3][4][5][6]31,38]. Electrochemical measurement suggested that the NCoSC material showed superior performance as compared to the NSC and NCuSC electrodes.…”

“…Higher retention of capacitance of NCoSC is attributed to the synergistic effect between the transition metals carbon coating. Improvement in electrical conductivity is attributed to the interconnected network structure of NCoSC electrode, contributing to achieving higher electrochemical properties [4][5][6]12,32,38]. EIS is a principal method to measure the internal resistance and ion diffusion properties of the materials.…”

“…The charge storage mechanism of the electrodes was evaluated by measuring the anodic peak current according to the scan rate. Whether the charge storage is capacitive controlled or diffusion controlled can be measured by plotting the log (i) vs. log (V) following the power law relationship (Equations ( 11)-( 12)) [6,12,19,38]:…”

“…The "b"values of the anodic peak were calculated to be 0.63, 0.64, and 0.68 (Figure 3c) of NCoSC, NCuSC, and NSC electrodes, respectively. The calculated value of "b"indicated that the redox process wascontrolled by the diffusion redox process when the transition metals were introduced in carbon-coated nickel sulfides [4,6,38]. The capacitance of the electrode materials was measured from the discharge time of the galvanostatic chargedischarge profiles.…”

“…The device showed~40 Ω R ct indicating faster charge transfer kinetics and good capacitive behavior of the device. The lower W-T (0.026) and W-P (0.16) values signified faster electrolyte ion diffusion of the electrodes in the device [5][6][7]31,38]. Figure 4e presents the GCD curves of the HSC device at different current densities from 2 to 15 A g −1 .…”