History of Vanadium Redox Battery
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 :
· 200 kW / 800 kWh installed by Mitsubishi Chemicals (1996) at Kashima- Kita Electric Power, Japan for load-levelling.
· 450 kW / 900 kWh installed 1996 by Sumitomo Electric Industries (SEI) at Tasumi Sub-Station, Kansai Electric, Japan, for peak shaving.
· 200 kW / 1.6 MWh installed by SEI (2000) at Kansai Electric, Japan for peak shaving.
· 170 / 1 MW installed by SEI (2001) at Hokkaido Electric Power Wind farm, Japan for wind turbine output power stabilisation.
· 1.5 MW / 1.5 MWh installed by SEI (2001) at Tottori Sanyo Electric, Japan for peak shaving and emergency back-up power.
· 250 kW / 500 kWh installed by VRB Power (2001) at Stellenbosch University for ESKOM Power Corporation, South Africa for peak shaving and UPS back-up power
· 500 kW / 5 MWh installed by SEI in 2001 at Gwansei Gakuin University Japan for peak shaving.
· 42 kW / 90 kWh installed by SEI in 2001 at CESI, Milan, Italy for R&D into distributed power systems.
· 500 kW / 2 MWh installed by SEI in 2003 in High-Tech factory in Japan for UPS/peak shaving.
· 250 kW / 1 MWh installed by Pinnacle VRB in 2003 for Hydro Tasmania on King Island for wind energy storage and diesel fuel replacement.
· 250 kW / 2 MWh installed for PacificCorp by VRB Power in 2004 in Moab, Utah, USA for voltage support, rural feeder augmentation.
· 4 MW / 6 MWh installed by SEI in 2005 for J Power at Subaru Wind Farm, Tomahae, Hokkaido, Japan for wind energy storage and wind power stabilisation.
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.