Our member Nataliya et al, have published an open acces review article on electron transfer processes for vanadium redox flow batteries. It concerns the complex reactions in diluted and concentrated vanadium electrolyte solutions.
The electrode processes play a decisive role in the efficiency and performance of vanadium redox flow batteries.
https://doi.org/10.1016/j.coelec.2019.10.003 
In particular, there is a little-noticed difference in the past between the properties of diluted and concentrated vanadium electrolyte solutions. For example, the results of measurements in diluted solutions cannot simply be transferred to higher and practical concentrations, since the structural properties of the vanadium species and thus also their chemical properties and reaction mechanisms are different.
