The iron-chromium redox flow battery (ICRFB) is considered the first true RFB and utilizes low-cost, abundant iron and chromium chlorides as redox-active materials, making it one of the most cost-effective energy storage systems.
The current density of current iron–chromium flow batteries is relatively low, and the system output efficiency is about 70–75 %. Current developers are working on reducing cost and enhancing reliability, thus ICRFB systems have the potential to be very cost-effective at the MW-MWh scale.
Iron–chromium flow battery (ICFB) is one of the most promising technologies for energy storage systems, while the parasitic hydrogen evolution reaction (HER) during the negative process remains a critical issue for the long-term operation. To solve this issue, In³⁺ is firstly used as the additive to improve the stability and performance of ICFB.
The electrolyte in the flow battery is the carrier of energy storage, however, there are few studies on electrolyte for iron-chromium redox flow batteries (ICRFB). The low utilization rate and rapid capacity decay of ICRFB electrolyte have always been a challenging problem.
Iron–sulfate redox flow battery Iron–sulfate redox flow battery is a relatively new type of RFB consisting of iron sulfate and anthraquinone disulfonic acid (AQDC) that shows the outstanding electrical performance, chemical durability, and the capacity retention ( 209 ).
[Show full abstract]such system is the iron-chromium (Fe–Cr) RFB, which utilizes a low-cost, high-abundance chemistry, but whose efficient and long-term operation is challenged by the poor Cr redox reaction kinetics and high hydrogen evolution reaction (HER) rates .