Review on Recent Progress in the Development of Tungsten Oxide Based Electrodes for Electrochemical Energy Storage

Abstract

Current progress in the advancement of energy‐storage devices is the most important factor that will allow the scientific community to develop resources to meet the global energy demands of the 21st century. Nanostructured materials can be used as effective electrodes for energy‐storage devices because they offer various promising features, including high surface‐to‐volume ratios, exceptional charge‐transport features, and good physicochemical properties. Until now, the successful research frontrunners have focused on the preparation of positive electrode materials for energy‐storage applications; nevertheless, the electrochemical performance of negative electrodes is less frequently reported. This review mainly focuses on the current progress in the development of tungsten oxide‐based electrodes for energy‐storage applications, primarily supercapacitors (SCs) and batteries. Tungsten is found in various stoichiometric and nonstoichiometric oxides. Among the different tungsten oxide materials, tungsten trioxide (WO3) has been intensively investigated as an electrode material for different applications because of its excellent charge‐transport features, unique physicochemical properties, and good resistance to corrosion. Various WO3 composites, such as WO3/carbon, WO3/polymers, WO3/metal oxides, and tungsten‐based binary metal oxides, have been used for application in SCs and batteries. However, pristine WO3 suffers from a relatively low specific surface area and low energy density. Therefore, it is crucial to thoroughly summarize recent progress in utilizing WO3‐based materials from various perspectives to enhance their performance. Herein, the potential‐ and pH‐dependent behavior of tungsten in aqueous media is discussed. Recent progress in the advancement of nanostructured WO3 and tungsten oxide‐based composites, along with related charge‐storage mechanisms and their electrochemical performances in SCs and batteries, is systematically summarized. Finally, remarks are made on future research challenges and the prospect of using tungsten oxide‐based materials to further upgrade energy‐storage devices.

Bimetallic tungstate nanoparticle-decorated-lignin electrodes for flexible supercapacitors

“…47 Shinde et al, in 2020, explained the pH-and potential-dependent behavior of tungsten in an aqueous medium, as well as the tungsten oxide crystal structures. 48 Various tungstate trioxide-based materials have been synthesized and tested extensively. However, tungstate trioxide has a low energy density and surface area.…”

“…Therefore, more research is required to enhance their performance as active electrode materials. 48 Wet chemical synthesis is one of the widely used techniques for the synthesis of NPs, which commonly deals with the chemical reaction occurring in its solution phase. Of the many methods available for the synthesis of NPs such as solvothermal and template synthesis, oriented attachment, self-assembly, etc., the wet chemical synthesis method offers a high degree of material reproducibility and controllability.…”

Electrospun CNF Supported Ceramics as Electrochemical Catalysts for Water Splitting and Fuel Cell: A Review

“…The catalyst reportedly performed better than pure Ni/NiO in terms of its Tafel slope, as the former reached 152 mV/dec, whereas for the latter the Tafel slope was reported to be 244 mV/dec elsewhere [101]. Tungsten dioxide (WO2) or trioxide (WO3) or suboxides (WO3-x) are known to have high metallic conductivity, and these are among the lucrative options in transition metal oxide groups [102]. However, they are prone to transform into tungsten carbide in high carbon concentration, and hence it is very difficult to synthesize them with CNFs, while carbonizing and yet retaining the suboxide structure [103].…”

“…Chen et al, (2016) [104] had demonstrated a novel technique to incorporate WO3-x in a controlled manner on the electrospun CNFs, where with the increment of tungsten precursor, the suboxide tended to increase, reducing the carbide formation. The study suggested that as the percent of precursor increased in the electrospinning solution, the HER activity increased in 0.5 M H2SO4 solutions, and with 30% of metal precursor the Tafel slope, this was found to be 89 Tungsten dioxide (WO 2 ) or trioxide (WO 3 ) or suboxides (WO 3-x ) are known to have high metallic conductivity, and these are among the lucrative options in transition metal oxide groups [102]. However, they are prone to transform into tungsten carbide in high carbon concentration, and hence it is very difficult to synthesize them with CNFs, while carbonizing and yet retaining the suboxide structure [103].…”

Morphology and crystal structure dependent pseudocapacitor performance of hydrated WO3 nanostructures

“…23,24 It is cost-effective and has excellent physical and chemical properties such as an n-type wide band gap, high density (7.13 g cm À3 ), various oxidation states (W 2+ -W 6+ ), and variable electrical conductivity (10-10 À6 S cm À1 ). 25,26 Also, WO 3 exists in various crystalline phases which makes WO 3 an extraordinary material amongst other TMOs for electrochromic, photocatalytic, gas sensing and electrochemical energy storage application. [27][28][29][30][31] Moreover, the various crystal phases including trigonal tunnels and cavities are highly favorable for tuning its physical properties and electrochemical ion intercalation.…”