Initial work on the Vanadium Redox Battery (VRB) at UNSW began in 1984. While other researchers had previously proposed the use of vanadium redox couples for redox cell applications, this was previously believed to be impractical due to the very low solubility of V(V) compounds which would have restricted the concentration of the vanadium electrolyte to a level much too low for practical use. The UNSW breakthrough came when it was discovered that highly concentrated V(V) solutions could be prepared in sulphuric acid. They found it was possible to prepare a highly concentrated solution which, unexpectedly, did not precipitate over a reasonable temperature range. This meant that reasonable vanadium solution concentrations could be achieved for practical systems.
The technology was taken from the initial concept stage through the development and demonstration of several 1-4 kW prototypes in stationary and electric vehicle applications over a 15 year period at UNSW. A further milestone in the UNSW R&D program, was the development of a low cost process for producing vanadium electrolyte from the vanadium oxide raw material.
The original UNSW technology was used through the 1980’s and 90’s for a number of exciting applications, some of which are detailed in the list below :
· MW-scale Sumitomo examples
· Golf cart
· House in Thailand
Since the mid-1980’s, Prof Skyllas-Kazacos and her collaborators have continued the development of the VRB technology with a focus on commercial manufacturing – developing low cost materials, and advanced techniques for low-cost, high-value production. NSi now holds a large portfolio of patents, and more than 25 years of research and know-how in Prof Skyllas-Kazacos and her research and technology transfer team.Core research at UNSW is continuing with a focus on 2nd Generation (vanadium bromide solutions with up to two times greater energy density) and 3rd Generation technologies that include vanadium oxygen redox fuel cells with potentially four times the energy density of the original VRB technology.