Construction of carnations-like Mn₃O₄@NiCo₂O₄@NiO hierarchical nanostructures for high-performance supercapacitors

Reasonable design for structure and composition of multi-component metal oxides is an effective and promising way to improve electrochemical performance of electrode materials. In this work, novel carnations-like Mn₃O₄@NiCo₂O₄@NiO hierarchical nanostructures are constructed by introducing CATB as structure-directing agents and adjusting hydrothermal reaction time. The perfect architecture maximizes the synergistic effect between components, providing more electrochemical reactive sites and promoting the diffusion and transfer of electrolyte ions. As a result, Mn₃O₄@NiCo₂O₄@NiO electrodes deliver an enhanced specific capacitance of 1905 F g⁻¹ at 1 A g⁻¹ and outstanding cyclic stability (92% of its initial capacitance is retained after 10000 cycles). Furthermore, ASC device which is assembled by the Mn₃O₄@NiCo₂O₄@NiO and activated carbon achieve excellent energy densities of 76.8 W h kg⁻¹ at power densities of 800 W kg⁻¹, proving the optimized Mn₃O₄@NiCo₂O₄@NiO is promising electrode material for supercapacitor. In addition, this work supplies helpful insights into rational design for structure and composition of multi-component metal oxides for enhancing electrochemical performance.