Molar optimization of MnO2 to form composite with Co3O4 by potentiodynamic electrodeposition for better electrochemical characterizations

Abstract

Manganese incorporated cobalt oxide thin films were deposited on stainless steel by using potentiodynamic electrodeposition via aqueous route. The structural elucidation reveals face-centered cubic Co 3 O 4 and orthorhombic MnO 2 having polycrystalline nature. FESEM and TEM show porous granular surface morphology along with nano-spikes. AFM image exhibits granular morphology. Optimized samples were studied for further electrochemical characterizations. All CV curves show mixed capacitive behavior. As compared to others, 1% manganese incorporation electrode shows maximum specific capacitance 605.39 F/g at 2 mV/s in 1M KOH. Chronopotentiometric charge-discharge studies report power density 18.12 kW/ kg, energy density 33.7 Wh/kg and columbic efficiency 73.89%. To know the internal resistive properties of the electrode, the electrochemical impedance analysis was carried out in the frequency range 1 mHz to 1 MHz. Using Nyquist plot, the observed internal resistance is ~ 0.78 Ω. ZsimpWin software was used to develop Randle's equivalent circuit to search the circuitry parameters associated with the cell.

Ni foam-supported Zn–Co–Ni ternary oxide nanosheet arrays derived from an MOF precursor with enhanced performances for supercapcitors and Ni–Zn batteries

“…Table 1 presents a comparison of the supercapacitor performance of the ZnCo 2 O 4 -NiO/NF electrode with other previously reported and related electrodes. 38,[42][43][44][45][46][47][48][49] For example, its capacitance is much higher than that of the single metal MOF or oxide electrodes, such as NiO/Ni-MOF-25 electrode (163.4 mA h g À1 at 1 A g À1 ), 42 NiCo 2 O 4 NS/CC electrode (183.1 mA h g À1 at 1.6 A g À1 ), 43 Ni-MOF electrode (804 F g À1 at 1 A g À1 ), 44 NiO-350 nanomaterial electrode (248.3 F g À1 at 1 A g À1 ), 45 Ni-NiO//CC electrode (184 mA h g À1 at 0.625 A g À1 ), 46 r-Ni 3 S 2 NSs electrode (1621.6 F g À1 at 0.2 A g À1 ), 38 and bimetallic oxide composite electrode ZnO/Co 3 O 4 @450 (690 F g À1 at 1 A g À1 ), 47 MnO 2 -Co 3 O 4 (605 F g À1 at 2 mV s À1 ), 48 and Co 3 O 4 NS/NF electrode (162.0 mA h g À1 at 1 A g À1 ). In the three-electrode system, we found that the selfsupported electrode has excellent electrochemical properties.…”

Elucidating the Role of Copper-Induced Mixed Phases on the Electrochemical Performance of Mn-Based Thin-Film Electrodes

“…Moreover, the synthesis conditions have a vigorous role in determining the properties of Mn 3 O 4 thin films . With the aim of improving the performance of Mn 3 O 4 electrodes, researchers have been utilized various approaches such as nano structuring, doping, forming composites, etc. − Incorporating a different element to form mixed oxides is one such strategy that may alter the electrochemical properties depending on the changes the dopant brings in the properties of the material. Thus, far, various elements such as Ni, Fe, Cr, Co, Zn, Cu, etc.…”