Hierarchically Ordered Porous CoOOH Thin‐Film Electrodes for High‐Performance Supercapacitors

We report a simple, cost‐effective, and potentially scalable approach for the fabricating hierarchically porous CoOOH thin‐film supercapacitors by combining a soft‐templating and a chemical‐bath deposition (CBD) method. The prepared electrode materials exhibit uniform morphology and highly ordered macropores, achieving a maximum specific capacitance of 387 F g −1 at a current density of 1 mA cm −2 , with a high energy of 19 Wh kg −1 and power density of 1713 W kg −1 . In addition, the porous CoOOH electrodes show good stability with a cycling efficiency >90 % after 5000 charge–discharge cycles, which could lead to the generation of novel energy‐storage devices with better efficiencies.