Investigation on mesoporous bimetallic tungstate nanostructure for high-performance solid- state supercapattery

Identification of electrode materials with excellent specific capacity and energy density are significant factors for the development of high-performance supercapattery device. Transition metal tungstate is an emerging electroactive material for supercapattery due to its excellent electrical conductivity and electrochemical properties. Herein, the mesoporous Ni(1-x)Co(x)WO4 nanomaterials were synthesized by a onestep hydrothermal method as an anode material for supercapattery. The apparent discrepancy in mesoporous structures was incited by varying the stoichiometric ratio of Ni/Co in the Ni((1-x))Co((x))WO(4 )system which lead to an increase in the electrochemical properties. Among the synthesized electrode materials, Ni(0.5)Co(0.5)WO(4 )electrode material delivers the high specific capacity of 634.55 Cg(-1) at 1 Ag-1 with an excellent rate capability of 92% after 10,000 cycles at 10 Ag-1. The solid-state supercapattery constructed with Ni0.5Co0.5WO4 and reduced graphene oxide as positive and negative electrodes, respectively. The device exhibits the maximum specific capacity of 134.70 Cg(-1) at 0.5 Ag-1 and energy density of 56.12 Wh kg(-1) at 500 W kg(-1) with long-term cyclic stability (90% capacity retentively after 20,000 cycles). The high performance of this electrode material has been attributed to the synergetic effect between bimetallic (Ni and Co) redox centers, a mesoporous structure that provides a larger redox cites, rich electrical conductivity, shorter diffusion length, and faster electrochemical kinetic rates for electrochemical reactions. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Identification of electrode materials with excellent specific capacity and energy density is crucial for high-performance supercapattery device. Transition metal tungstate, like mesoporous Ni(1-x)Co(x)WO4, shows promising properties for supercapattery due to its electrical conductivity. Among the synthesized electrode materials, Ni(0.5)Co(0.5)WO(4) shows high specific capacity and excellent rate capability, making it a potential candidate for supercapattery applications.