Homogeneous hierarchical NiMoO4@NiMoO4 nanostructure as a high-performance anode material for electrochemical energy storage

TL;DR

This paper introduces a novel homogeneous hierarchical NiMoO4@NiMoO4 nanostructure with enhanced electrochemical energy storage capabilities, demonstrating superior performance and stability in supercapacitor applications due to its unique architecture.

Contribution

The study presents a new homogeneous hierarchical NiMoO4@NiMoO4 nanostructure synthesized via a two-stage hydrothermal process, showing improved electrochemical performance over traditional structures.

Findings

Enhanced energy density of 47.2 Wh/kg in supercapacitors.

High cycling stability with 91.4% capacity retention after 4000 cycles.

Significant reduction in electrode resistance due to hierarchical structure.

Abstract

Here we report the extraordinary electrochemical energy storage capability of NiMoO4@NiMoO4 homogeneous hierarchical nanosheet-on-nanowire-arrays (SOWAs) synthesized on nickel substrate by a two-stage hydrothermal process. Comparatively speaking, the SOWAs electrode displays improved electrochemical performances than the bare NiMoO4 nanowire arrays. Such improvements can be ascribed to the characteristic homogeneous hierarchical structure which not only effectively increases the active surface areas for fast charge transfer, but also reduces the electrode resistance significantly by eliminating the potential barrier at the nanowire/nanosheet junction, which is usually an issue in other reported heterogeneous architectures. We further evaluate the performances of the SOWAs by constructing an asymmetric hybrid supercapacitor (ASC) with the SOWAs and activated carbon (AC). The optimized ASC shows excellent electrochemical performances with 47.2 Wh/kg in energy density at 1.38 kW/kg at 0-1.2 V. Moreover, the specific capacity retention can be as high as 91.4% after 4000 cycles, illustrating the remarkable cycling stability of the NiMoO4@NiMoO4//AC ASC device. Our results show that this unique NiMoO4@NiMoO4 SOWAs display great prospect for future energy storage applications