Facile fabrication of hierarchical porous rose-like NiCo2O4 nanoflake/MnCo2O4 nanoparticle composites with enhanced electrochemical performance for energy storage

Abstract

The rational design of three-dimensional (3D) hierarchical porous architectures possessing the advantages of improved electrical conductivity and reduced volume change during charge–discharge processes has been proved to be an effective way for enhancing the electrochemical performance of binary metal oxides and related hybrids. Herein, uniform 3D hierarchical porous rose-like NiCo₂O₄/MnCo₂O₄ is controllably fabricated through a facile hydrothermal process followed by a subsequent heat treatment, which exhibits high cycling stability (1009 mA h g⁻¹ at 1000 mA g⁻¹ after 600 cycles), high specific capacity and excellent rate capability as anodes for lithium ion batteries. In addition, the NiCo₂O₄/MnCo₂O₄ displays an initial specific capacitance of 911.3 F g⁻¹ as a supercapacitor electrode at 5 A g⁻¹. Its excellent electrochemical performances may originate from its unique hierarchical and porous structure, which can buffer the volume expansion and increase the contact area between the electrode and electrolyte. The as-obtained 3D hierarchical porous rose-like NiCo₂O₄/MnCo₂O₄ composite exhibits outstanding electrochemical performances, which is a promising candidate for the next-generation energy storage electrodes.