LAUSR

Abstract We report an efficient energy storage electrode based on well-defined, interconnected NiO nanosheets (NiO-NS) grown directly on a mesoporous TiN ( meso -TiN) film via a solvothermal method. A mesoporous TiO 2 ( meso -TiO 2 ) film is prepared using a graft copolymer template and then thermally annealed in ammonia at 800 °C to convert meso -TiO 2 into meso -TiN. The ultrathin interconnected NiO-NS provide a large surface area and effective electron pathway, which enhance their specific capacitance and electrochemical properties. In contrast, a less-organized structure with poor homogeneity, low porosity and some cracks is formed for dense-TiN film prepared without the PVC-g-POEM. The meso -TiN film acts as an efficient conductive support to grow the NiO-NS and enhances the diffusion of electron/electrolyte ions. Despite its low thickness ( meso -TiN supercapacitor exhibits a high capacitance of 104 mF cm −2 and good cycle stability (86% capacitance retention) owing to the synergetic effects of the NiO-NS and meso -TiN heteronanostructure. The NiO-NS/ meso -TiN film is also applied to a flexible substrate and exhibits no cracks after bending; thus, our work provides an efficient way to design flexible energy storage devices using graft-copolymer-directed heteronanostructures.