Synthesis of Cobalt Oxide Nanostructures on Carbon Paper Using Intense Pulsed Light (IPL) and Supercapacitor Electrode Applications

Transition metal oxides have received tremendous interests in supercapacitor materials over the last decade because they can provide higher energy density than conventional carbon materials and better electrochemical stability than polymer materials. They not only store energy like electrostatic carbon materials but also exhibit electrochemical faradaic reactions between electrode materials and ions within appropriate potential windows. Several methods have been used to synthesize metal oxide nanostructures including chemical bath deposition, hydroxide decomposition, thermal decomposition of carbonates, nanocasting, electrodeposition, combustion, coprecipitation, and the sol-gel method. Many of these have drawbacks in that they are energy consuming, lengthy and involve multiple steps. Especially, all methods require calcinations/heat treatment at 200-600^oC for 1-24hrs. Therefore, faster, more facile and energy efficient methods for metal oxide nanostructure production are of interest. Here we report an agile and facile method for the preparation of high-performance supercapacitive cobalt oxide nanoflakes by using an intense pulsed light (IPL) technology. By this method, the cobalt oxide formation can be accomplished within milliseconds by irradiating the broad wavelength light with high energy density on cobalt oxide precursor, which is exceptionally faster than other metal oxide formation methods. We have fabricated cobalt oxide nanoflakes on flexible carbon-paper substrate by using the IPL technique. The as-prepared substrates are further utilized as a supercapacitor electrode, and their supercapacitive performance will be discussed in the presentation.