Aqueous organic redox-flow batteries: experimental and techno-economic analysis

In the recent years’ pursue of affordable and high-performing energy storage devices, redox-flow batteries have shown great potential for long-duration operations. With cheaper and more environmentally-sustainable materials with respect to more mature vanadium-based devices, aqueous organic redox flow batteries (AORFBs), currently constitute the research focus to bring out the full potential of redox-flow technology. Hovewer, due to being an innovative technology, AORFBs behavior has yet to be investigated deeply, both from an operational and from a techno-economic point of view. In this work, an AORFB prototype battery system device has been experimentally tested at Officine Edison Laboratory in Turin. Numerous experimental tests have been carried out, to effectively assess the performances of an AORFB battery system in many operational conditions, for both deep depth of discharge and reduced state of charge ranges. Energy and efficiency results have being reported, as well as considerations of auxiliary consumptions’ impacts on AORFBs’ round-trip efficiency. Finally, a techno-economic analysis has been carried out, to evaluate the actual feasibility of AORFB devices. A comparison with vanadium-based technology has been highlighted, bringing peculiar considerations for possible near-future implementations. The experimental campaign has shown AORFBs’ high performance in long duration applications, with electrochemical efficiency values up to 86% in different state of charge conditions. Moreover, this work shows AORFBs’ competitiveness with respect to vanadium-based devices.