Engineering of nickel, cobalt oxides and nickel/cobalt binary oxides by electrodeposition and application as binder free electrodes in supercapacitors

Abstract

Cobalt oxide, nickel oxide and cobalt/nickel binary oxides were synthesised by electrodeposition. To fine tune composition of CoNi alloys, growth parameters including voltage, electrolyte pH/concentration and deposition time were varied. These produced nanomaterials were used as binder free electrodes in supercapacitor cells and tested using three electrode setup in 2 MKOH aqueous electrolyte. Cyclic voltammetry and galvanostatic charge/discharge were used at different scan rates (5–100 mV/s) and current densities (1–10 A/g) respectively to investigate the capacitive behaviour and measure the capacitance of active material. Electrochemical impedance spectroscopy was used to analyse the resistive/conductive behaviours of these electrodes in frequency range of 100 kHz to 0.01 Hz at applied voltage of 10 mV. Binary oxide electrode displayed superior electrochemical performance with the specific capacitance of 176 F/g at current density of 1 A/g. This hybrid electrode also displayed capacitance retention of over 83% after 5000 charge/discharge cycles. Cell displayed low solution resistance of 0.35 Ω along with good conductivity. The proposed facile approach to synthesise binder free blended metal electrodes can result in enhanced redox activity of pseudocapacitive materials. Consequently, fine tuning of these materials by controlling the cobalt and nickel contents can assist in broadening their applications in electrochemical energy storage in general and in supercapacitors in particular.

Investigating the Potential Use of Ni‐Mn‐Co (NMC) Battery Materials as Electrocatalysts for Electrochemical Water Splitting

“…In the case of the unmodified NF electrode (Figure 1c) there is a clear distinction between the redox process and onset of the OER, however this is not evident for the NMC electrodes and indicates that the process is perturbed by the presene of Co and Mn elements within the electrode material. The presence of secondary metals is known to affect the redox behaviour of Ni oxides which results in a much broader oxidation response [57] . From Figure 1 it can be seen that the potential range also encompasses the HER region which can be seen by the increase in current below ca.…”

Catalytic CoSn Perovskites for High-Performance Asymmetric Hybrid Supercapacitor and Efficient Oxygen Evolution Reaction: Experimental Investigation and DFT Validation

“…14−17 Particularly, in the context of binary metal oxides for supercapacitors, Abbas et al synthesized the binder-free CoNi binary oxide electrode, which shows an electrochemical performance of 176 F/g at a current density of 1 A/g. 18 Ishaq et al synthesized a binary composite of reduced graphene oxide and cobalt iron oxide (rGO/CoFe 2 O 4 ) and it exhibits a gravimetric capacitance of 97 F/g at 5 mV/s. Furthermore, with the addition of polypyrrole (PPy), the gravimetric capacity of rGO/CoFe 2 O 4 /PPy increased to 164 F/g.…”

“…Binary metal oxides like Co–Ni, Mn–Co, Co–Fe, and Co–Sn-based hydroxide/oxides have been used in various applications like lithium-ion batteries, electrocatalysts, and supercapacitors. − Particularly, in the context of binary metal oxides for supercapacitors, Abbas et al synthesized the binder-free CoNi binary oxide electrode, which shows an electrochemical performance of 176 F/g at a current density of 1 A/g . Ishaq et al synthesized a binary composite of reduced graphene oxide and cobalt iron oxide (rGO/CoFe 2 O 4 ) and it exhibits a gravimetric capacitance of 97 F/g at 5 mV/s.…”

Microwave-Assisted Synthesis of Flower-like MnMoO4 Nanostructures and Their Photocatalytic Performance

“…They possess an extremely large bivalent cation with an ionic radius >0.99 for scheelite structures, such those of Ba, Sr, Pb, or Ca. In this way, the binary metal oxide manganese molybdate (MnMoO 4 ) has received a lot of research interest recently because of its affordability, viability as oxidation states, improved electrical conductivity, and good thermal and chemical stability, allowing it to achieve superior electrochemical performance [23,24].…”