NiMnOx/TiN/CC electrode with a branch–leaf structure: a novel approach to improve the performance of supercapacitors with high mass loading of amorphous metal oxides

Abstract

Amorphous metal oxides are provided with tremendous merits in energy storage devices for their high structural disorder and excellent electrochemical activity. Unfortunately, hindered by the large inherent resistance, their electrochemical performance under high mass loading is unsatisfactory. Herein, an effective strategy for the branch–leaf structure is proposed to fabricate novel high mass loading electrode materials with the capability of high-speed charge transport and excellent capacitance performance. Under the synergistic effect of the branch–leaf structure, the NiMnO_x/TiN/CC electrode under 10.12 mg cm⁻² mass loading shows 4882 mF cm⁻² areal capacitance at 5 mA cm⁻², high-speed charge transfer capability, and great rate performance. It is the first time that the excellent performance of supercapacitors has been achieved in high mass loading amorphous metal oxides. Moreover, the assembled asymmetric supercapacitor device exhibits extreme power and energy density (0.65 W h cm⁻² at 5.3 W cm⁻²), which are superior to those of most state-of-the-art supercapacitors. A novel path has been opened up for the application of energy storage devices with high mass loading of amorphous materials.