Development of a novel tungsten oxide supercapacitor

Lead Research Organisation: University of Strathclyde
Department Name: Chemical and Process Engineering

Abstract

Background
The storage of electrical power from renewable, off-grid electrical energy generation is becoming an increasingly important challenge as the drive towards energy sustainability continues to shape our energy policies. Conventional battery technologies are being placed under increasing demands in relation to storage and supply on demand. The performance indicators for such devices and materials employed in their fabrication are their capacity, power/energy density, rate of charge/discharge capabilities, cycle life (which is governed by material durability), as well as their safety and cost.
Aims & objectives
The aim of this project will be to develop a novel and simple charge storage device based on nanostructured metal oxide materials, in particular tungsten-tungsten oxide, W-WO3-x (WOx), which displays pseudo-capacitive redox behaviour. The essential chemistry of the process is in the highly reversible reaction
e- + H+ + WVIO3 - HxW(1-x)VIWxVO3
which describes intercalation of protons into a WO3 matrix and concurrent reduction of WVI to WV. In effect, during the charge and discharge cycle, the nanostructured tungsten-oxide is reduced reversibly to a hydrogen-tungsten-bronze. There has been some investigation on the pseudo-capacitive behaviour of tungsten oxides, but there has been limited (if any) studies on architectures which can be adapted for fabrication of capacitive devices.
If the nanostructured material were grown on the metal itself, this could provide a simple device structure which could provide both mechanical stability to the system as well as serve as a current collector. This would allow the intercalation redox process to proceed rapidly as well as lowering internal resistance, while providing a simple and low cost design for the device.
The principal objectives of the project will be
1. Optimisation of bottom-up growth of nanostructured tungsten oxide on tungsten foil electrodes
2. Interrogation of performance of these tungsten oxide materials
3. Assessment of capacitive charge and discharge performance during long term cycling.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/R513349/1 01/10/2018 30/09/2023
2270808 Studentship EP/R513349/1 01/10/2019 31/03/2023 Thomas Cadden