Interlaced NiMn-LDH nanosheet decorated NiCo₂O₄ nanowire arrays on carbon cloth as advanced electrodes for high-performance flexible solid-state hybrid supercapacitors

Abstract

The development of flexible energy storage devices for portable and wearable electronics has aroused increasing interest. In this work, three-dimensional hierarchical NiCo₂O₄@NiMn-LDH nanowire/nanosheet arrays have been successfully fabricated on carbon cloth through a facile hydrothermal and calcination synthetic method. Benefiting from the sophisticated hybrid nanoarchitectures with desirable structure and components, the optimized NiCo₂O₄@NiMn-LDH hybrid electrode is found to deliver a remarkable specific capacity of 278 mA h g^-1 at 2 mA cm^-2 and a good rate capability of 89.1% retention at 20 mA cm^-2. Detailed analysis of the reaction kinetics for the hybrid electrode clearly indicates the dominant diffusion-controlled contribution to the total capacity. In addition, a flexible solid-state hybrid supercapacitor is assembled by taking NiCo₂O₄@NiMn-LDH and activated carbon as the cathode and anode, respectively, which manifests a maximum energy density of 47 W h kg^-1 at a power density of 357 W kg^-1 as well as an excellent long-term cycling stability (95.6% retention after 5000 cycles over 8 mA cm^-2). Our work demonstrates the great potential of this core/shell hybrid nanostructure as an advanced battery-type electrode for high-performance flexible energy storage devices.