High Specific Capacitance of the Electrodeposited MnO2 on Porous Foam Nickel Soaked in Alcohol and its Dependence on Precursor Concentration

Abstract

In this work, we used the mixed solution of manganese acetate and sodium sulfate to deposit manganese dioxide on the three-dimensional porous nickel foam that was previously soaked in alcohol, and then the effects of solution concentrations on their capacitance properties were investigated. The surface morphology, microstructure, elemental valence and other information of the material were observed by scanning electron microscope (SEM), Transmission Electron Microscope (TEM), X-ray photoelectron spectroscopy (XPS), etc. The electrochemical properties of the material were tested by Galvanostatic charge-discharge (GCD), Cyclic Voltammetry (CV), Chronoamperometry (CA), Electrochemical impedance spectroscopy (EIS), etc. The MnO2 electrode prepared at lower concentrations can respectively reach a specific capacitance of 529.5 F g−1 and 237.3 F g−1 at the current density of 1 A g−1 and 10 A g−1, and after 2000 cycles, the capacity retention rate was still 79.8% of the initial capacitance, and the energy density can even reach 59.4 Wh Kg−1, while at the same time, it also has a lower electrochemical impedance (Rs = 1.18 Ω, Rct = 0.84 Ω).

Effects of electrodeposition time on a manganese dioxide supercapacitor

“…In the recent years, scientists have been paying more and more emphasis to supercapacitors, which are regarded as renewable energy storage devices due to the advantages of rapid charging and discharging, high energy density, power density, outstanding rate performance, and long-term cycling stability performance. [3][4][5][6] Meanwhile, their applications in numerous elds have promising prospects, particularly in hybrid vehicles and military equipment. 7,8 In general, supercapacitors can be classied into two categories depending on the mechanism of energy storagepseudocapacitors (PCs) and electric double-layer capacitors (EDLCs).…”

Hydrothermal synthesis of NiO nanoparticles decorated hierarchical MnO2 nanowire for supercapacitor electrode with improved electrochemical performance

“…K. M. Racik et al [ 50 ] found good electrochemical performance in their MnO 2 /NiO electrodes while KOH is used as an electrolyte. M. Zhange et al [ 51 ] reported high specific capacitance (529 F/g at 1 A/g) in their electrodeposited MnO 2 supercapacitor on 3D porous Ni foam. From this discussion, it is clear that the incorporation of NiO improves the electrochemical performance of MnO 2 .…”