The Vanadium Redox Flow Battery (VRFB) has been the first redox flow battery to be commercialized and to bring light to the flow battery technology. Thanks to the work performed by Monash university’s professor Maria Skyllas-Kazacos on VRFB over the 1980s, this technology is gaining field to the world adopted energy storage system, lithium-ion battery.
In the latest update of the IDTechEx report, “Redox Flow Batteries 2021-2031”, a substantial forward-looking approach has been assumed in forecasting the trend of adoption of this technology, with a multi-billion market size in 2031.
The results of IDTechEx’s research show that the large-scale adoption of RFB is just a matter of time.
Redox Flow Batteries will be employed as a workhorse device, as defined by redT’s website. redT merged with US Avalon battery in 2020, founding one of the largest VRFB companies, Invinity.
The large adoption of RFB systems doesn’t imply that Li-ion batteries will disappear from the market, but simply that the two systems will address different aspects. In fact, IDTechEx expects Li-ion batteries to be mostly employed for a short duration of storage, hence focusing their application for high power applications with an average storage time between 1h and 5h. Possibly, the range addressed by Li-ion batteries might increase over the years.
Therefore, the RFB market will point to the large amount of energy this system can store. Amount of energy, which is provided due to the low capacity loss per cycle.
The VRFB device is the most studied and developed technology among the RFB systems. The presence of Vanadium as electrochemical species in the catholyte and anolyte reduces the issue of cross-mixing of the electrolyte.
Over the last few years, the price of vanadium has been one of the parameters affecting the adoption of this technology. To compensate for this issue, the vanadium flow battery producers started to collaborate with vanadium electrolyte companies to cope with this problem. One of the solutions to the high vanadium cost was to offer a leasing scheme for the electrolyte. A company like Invinity offers, in collaboration with Bushveld Energy, a leasing option to purchase the electrolyte separately. In this way, the cost of the battery is reduced, making VRFB more affordable. A further advantage of the vanadium electrolyte is the possibility to recycle it.
Similar to Bushveld energy, LARGO resources a Canadian mining company started to address the vanadium redox flow battery field, with the acquisition of Vionx Energy’s asset for $35 million at the end of 2020.
The Iron flow battery (IRFB) is one of the candidates to compete with VRFB in populating the large-scale stationary market. The IRFB is an interesting candidate for large-scale applications due to the low cost of iron, which leads to a reduced capital cost. In addition, it offers the possibility to easily recycle the electrolyte, and avoid cost fluctuation of the electroactive material, as it might happen to vanadium. In addition in a recent study comparing VRFB, ZBB, and IRFB production, has also showed the IRFB to be the less polluting technology all over the production process.
Although the IRFB will likely compete for large-scale applications with VRFB, the two technology will bring to the market a different quality of storage system. This will in turn allow a larger variety of products for the customer.
The last promising RFB system is, of course, the Zinc/Bromine flow battery (ZBB). From a technical point of view, ZBB is a hybrid flow battery, which means one of the electrodes (the zinc electrode) is not liquid. In the specific case of ZBB, it is in fact a solid metal. This offers some advantages, like a reduced dimension and weight of the battery, which makes this battery well suited for indoor applications, and some disadvantages like a linked energy/power capacity relation. From a chemical point of view, the zinc metal undergoes an electroplating/