CoNi₂S₄ Electrode with High Mass‐Loading for High‐Energy‐Density Supercapacitor: Role of S‐Containing Anions Exchange

Abstract

Anion exchange is recognized as an effective method to regulate the composition, electronic conductivity, and electrochemical behavior of the transition metal-based compounds. In this work, anion exchange is adopted as a rational post-treatment route to facilitate the capacitive activity of CoNi 2 S 4 nanoparticle arrays grown on carbon cloth (CC) with high mass-loading. As soaked in saturated Na 2 S solution, the CoNi 2 S 4 /CC electrode showed an increased capacity from 483 C g À 1 to 841 C g À 1 at 10 mA cm À 2 with excellent rate performance and stable cycling performance, which was superior to the CoNi 2 S 4 /CC electrode activated by NaBH 4 reduction. Anion exchange was beneficial for enhancing the crystallinity, retaining the adhesion of nanoarrays, and realizing low resistance nature in a mild route. The asassembled CoNi 2 S 4 /CC//activated CC hybrid supercapacitor delivered a high areal capacitance of 1.28 F cm À 2 at 5 mA cm À 2 , and achieved an energy density of 0.58 mWh cm À 2 at a power density of 4.5 mW cm À 2 with excellent cycle stability with 90.6 % capacity retention after 10000 cycles.

In Situ Fabrication of Hierarchical CuO@CoNi-LDH Composite Structures for High-Performance Supercapacitors

“…The energy density and power density of the device were calculated from the GCD curve, and the resulting Ragone plot is shown in Figure g. The performance exhibited by the material surpasses that of CuO materials, LDH-based materials, and other types of heterogeneous composite structures in supercapacitor operation. ,− ,− The corresponding electrochemical properties are summarized in Table S1. The electrochemical studies of individual devices were conducted, and the electrochemical performances of two supercapacitors in series and parallel are shown in Figure h,i, respectively.…”

Effects of Heteroatom Doping and Physicochemical Character on the Electrochemical Properties of Graphene Sheets

“…These features of EEG samples have been associated with the contribution of slow faradaic reactions with low reversibility in the charge transfer process at a specific scan rate. [9,44] Further investigation of electrochemical characteristics of the samples were carried out through the variation of the specific capacitance values calculated at different scan rates and the EIS measurement results.…”