Ultrathin NiFe-layered double hydroxide decorated NiCo ₂ O ₄ arrays with enhanced performance for supercapacitors

Designing and synthesizing core/shell nanostructures materials as binder-free electrodes is an effective strategy to enhance the electrochemical performance of supercapacitors. In this work, the hierarchical NiCo ₂ O ₄ @NiFe-layered double hydroxide core/shell arrays are successfully constructed via a stepwise hydrothermally grow method and investigated for application in supercapacitors. With the assistance of the hierarchical core/shell structures and the synergetic effect between NiCo ₂ O ₄ and NiFe-layered double hydroxide nanosheets, the hybrid electrode discloses significant melioration in property, including the improvement in number of the electrochemically active sites and short transport path lengths for both electrons and ions. Thus, the core/shell electrode exhibits remarkable electrochemical performance, such as a high areal capacity (12.3 F cm ⁻² ) and good cycling stability (83.1% capacitance retention after 2000 cycles). Our trials testify that the hierarchical NiCo ₂ O ₄ @NiFe-layered double hydroxide core/shell nanowire arrays are advantageous for potential applications in energy storage devices.