Development of supercapacitors based on Cobalt and Nickel hydroxides

In the present days the lack of efficient energy storage systems becomes clearly apparent. Known systems rarely show high power density and high energy density at the same time. To overcome this problem research on so-called supercapacitors, a combination of electrochemical double layer capacitors and pseudocapacitors as well as their hybrids, is currently done. Next to carbon materials and conducting polymers, transition metal oxides have shown to be appropriate candidates.

Among transition metal oxides ruthenium oxide exhibits so far the best performance, but due to the high cost and toxicity its usability is limited. While manganese oxides seems to be a good substitute considering a single metal oxide, nickel cobalt double layered hydroxides (Ni-Co-DLH) have drawn some attention as a very high specific capacitance of over 2000 F g^-1 was found for them. Hence the group of Ni-Co-DLHs has become an interesting topic for further investigations.

The purpose of this research project is to obtain new Ni-Co-DLH-based materials. Synthesis will be done by the chemical bath deposition method. As substrates mirco- and mesoporous materials like carbon nanotubes, Ni-foam are used, graphene will be added for further improvement. Characterization will be done by X-ray diffraction (XRD), scanning electron microscopy (SEM) and infrared spectroscopy (IR). Electrochemical data will be obtained by cyclovoltammetry (CV), charge-discharge measurements and electrochemical impedance measurements (EIS).

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