Climate change and the decreasing availability of fossil fuels
require a move towards sustainable and renewable energy
resources. Electrochemical supercapacitors are currently the
focus of intense research because they are extremely useful
energy storage devices that release energy quickly.1–10 Many
materials have been evaluated as active electrodes for electrochemical supercapacitors, including carbon-based materials,
conducting polymers and transition metal oxides.11,12 However,
their performance needs to be substantially improved to meet
the future requirements of energy devices, which range from
portable electronics to hybrid electric vehicles