Handbook of Energy Storage for Transmission or ... - W2agz.com

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back-up system for submarines (Australian Department of Defense), a battery for an
electric golf car, and a 200 kW / 800 kWh load-leveling battery (Mitsubishi
Chemicals/Kashima-Kita Electric Power Corporation, Japan).
In 1998, intellectual property rights to the technology were sold to Pinnacle VRB, Ltd.
(Sydney, Australia). Sumitomo Electric Industries (Osaka, Japan) acquired the ETL
technology and, under license to Pinnacle VRB, further developed the technology by
designing cell stacks and complete integrated systems.
In addition to the UNSW/Sumitomo development efforts, several VRB-related
technologies have been under development since 1995 by Squirrel Holdings, Ltd
(Thailand). These include a series-flow battery, electrolyte production, and a vanadiumbased
fuel cell that is fueled by locally-grown agricultural crops.
1.3. Technology Description
As illustrated in Figure 2, the VRB cell is based upon electron transfer between different
ionic forms of vanadium. At the negative electrode, V 3+ is converted to V 2+ during
battery charging by accepting an electron. During discharge, the V 2+ ions are reconverted
back to V 3+ and the electron is released. At the positive electrode, a similar reaction takes
place between ionic forms V 5+ and V 4+ .
Figure 2
Principles of the VRB (Courtesy SEI)
Vanadium Redox Battery 8