Advances in Electrochemical Energy Devices Constructed with Tungsten Oxide-Based Nanomaterials

Abstract

Tungsten oxide-based materials have drawn huge attention for their versatile uses to construct various energy storage devices. Particularly, their electrochromic devices and optically-changing devices are intensively studied in terms of energy-saving. Furthermore, based on close connections in the forms of device structure and working mechanisms between these two main applications, bifunctional devices of tungsten oxide-based materials with energy storage and optical change came into our view, and when solar cells are integrated, multifunctional devices are accessible. In this article, we have reviewed the latest developments of tungsten oxide-based nanostructured materials in various kinds of applications, and our focus falls on their energy-related uses, especially supercapacitors, lithium ion batteries, electrochromic devices, and their bifunctional and multifunctional devices. Additionally, other applications such as photochromic devices, sensors, and photocatalysts of tungsten oxide-based materials have also been mentioned. We hope this article can shed light on the related applications of tungsten oxide-based materials and inspire new possibilities for further uses.

Synthesis and electrochemical studies of WO3‐based nanomaterials for environmental, energy and gas sensing applications

“…To date, details on the coloration mechanism of WO 3 ‐based electrochromic systems remain elusive. The effects in crystalline WO 3 ‐based systems are often discussed in terms of the optical transitions or collective excitation of quasi‐free electrons in not fully occupied bands in a one‐electron band structure; in the case of amorphous films, the effects are often described in terms of intervalence charge transfer 101–107 . To improve the performance of the ECDs, nanostructured WO 3 with different structures and WO 3 based nanocomposites have been investigated.…”

“…The effects in crystalline WO 3 -based systems are often discussed in terms of the optical transitions or collective excitation of quasi-free electrons in not fully occupied bands in a oneelectron band structure; in the case of amorphous films, the effects are often described in terms of intervalence charge transfer. [101][102][103][104][105][106][107] To improve the performance of the ECDs, nanostructured WO 3 with different structures and WO 3 based nanocomposites have been investigated. Ultrathin WO 3 nanosheets with some desirable properties, such as a high specific surface area, good substrate contacts, and permeable channels, are expected to make them promising candidate materials for ECDs.…”

Ultrathin Al2O3 Protective Layer to Stabilize the Electrochromic Switching Performance of Amorphous WOx Thin Films

“…The need for energy saving and sustainable technologies is of increasing priority in order to counteract global climate change despite a growing population and the associated increase in primary energy demand. [1,2] Due to their diversity and versatility, transition metal oxides play a central role in energy-related applications, [3][4][5][6][7] such as lithium-ion batteries, supercapacitors, photo-and electrocatalysts or electrochromic (EC) devices. [8][9][10][11][12][13][14][15][16][17] In order to stabilize the oxides against undesired side reactions, thin inert protective layers can be used as shown, e.g., for cathode materials in lithium-ion batteries.…”

Lithium confinement and dynamics in hexagonal and monoclinic tungsten oxide nanocrystals: a 7Li solid state NMR study

“…2 Tungsten trioxide has long been studied for its structural, electronic, and electrochromic properties, and it has become a hot topic in fields like photoluminescense, 3 NIR light-shielding, 4,5 plasmonics, 6,7 thermoelectrics, [8][9][10][11] superconductivity, 1,12,13 gas sensing, 14 supercapacitors, 15 batteries, [16][17][18] catalysis 19 or photocatalysis, 20 and for water splitting devices 21 and solar cells. 22,23 Tungsten trioxide (WO 3 ) has a ReO 3 -type structure with corner-sharing WO 6 octahedra. 24 Changes in temperature and pressure lead to rigid tilts of the WO 6 octahedra.…”