Vanadium air/redox flow batteries

Energy storage is considered as one of the key component of forthcoming low carbon energy scenario expected to be developed by using renewable sources of energy such as wind, tidal and solar energy. Electrochemical energy storage systems particularly electrochemical batteries provide the most appropriate solution to enhance grid stability and improve poor reliability caused by energy generation through intermittent renewable sources of energy, thanks to distinctive properties of electrochemical battery systems including flexibility, cost effectiveness, scalable energy storage and combination of efficiency. Therefore, intensive research drive has been initiated for the development of electrochemical energy storage systems with particular emphases directed towards the improvements of vanadium air/redox flow batteries since vanadium flow batteries (VFBs) are one of the most promising electrochemical energy storage systems with wide ranging applications especially in the field of renewable energy. After the invention of generation 1 (G1) vanadium flow batteries (VFBs) in 1985 at the University of New South Wales (UNSW), VFBs have been successfully adopted in various demonstrational projects and field trails around the globe however, G1 VFBs suffer from inferior energy/power densities restricting their commercial applications. Broad research activity has commenced in order to improve their performance at the same time limiting their production cost by using cost effective components.

This chapter gives an overview of innovation of not only in material development including electrode, electrolytes and membrane materials but also different stock designs and their impact on the performance of vanadium air/redox flow batteries. Also the evolution of vanadium redox flow batteries from the beginning at UNSW to date has been reviewed and discussed in details.