Chapter 10 – Vanadium redox flow batteries (VRBs) for medium- and large-scale energy storage

The all-vanadium redox flow battery (VRB) that was pioneered at the University of New South Wales in Australia is currently considered one of the most promising battery technologies that will be able to meet the growing global need for energy storage solutions. It has been extensively field tested in a range of applications, including wind and solar energy storage, load leveling, peak shaving, and emergency backup systems with kW to MW power rating, and has demonstrated overall energy efficiencies of up to 80% and more than 200,000 cycles. Although the energy density of the original is lower than other competing technologies, it is adequate for most stationary applications, while also offering significantly lower costs and improved safety compared with Li-ion, sodium-sulfur, and other flow battery chemistries. With recent advances in mixed-acid electrolytes, however, considerable improvements in energy density operating temperature range are expected to further extend the range of applications, which could potentially extend to electric vehicles.