Here are a bunch of new acronyms for the field. This is getting complicated! https://www.pv-magazine.com/2021/01/20/the-best-redox-flow-battery-tech/
The researchers also looked at alternative aqueous inorganic pure flow batteries such as vanadium-oxygen redox flow batteries (VORFBs), vanadium–bromine redox flow batteries (VBFBs), hydrogen–bromine flow batteries (HBFBs), polyoxometalates-based redox flow batteries (POMs-RFBs), and aqueous organic redox flow batteries (AORFBs). In addition, they analyzed different materials for electrolytes and membranes. They presented the case for semi-solid flow batteries (SSFBs) and solid targeted/mediated/boosted flow batteries (SMFBs).
They also studied hybrid flow/non-flow devices such as metal-solution-based redox pair flow batteries, as well as zinc-based, iron-based, copper-based or metal air-based redox flow storage systems. In addition, the scientists looked at the potential of solar redox flow batteries (SRFBs), air-breathing sulfur flow batteries, and metal-CO2 batteries.