Abstract
Semi-solid redox flow batteries (SSRFBs) consist of electrochemically active particle suspensions as electrodes and can potentially be applied to large scale energy storage. Invented just a decade ago, these batteries already face dwindling commercial value as they can be too complex to study systematically. This review illustrates the depth and width of the state of the art of knowledge that needs to be taken into account. Additionally, this work shows how SSRFBs are an embodiment of complex systems. Conventional theoretical paradigms, experimental tools, and modeling methods generally reduce the size of the problem to solve it. However, this is nearly impossible for highly complex systems with interdependent parameter relationships. This review shows how rheology plays a very significant role in impacting electrochemistry. It concluds that the fastest way to optimize SSRFBs is by obtaining as many experimentally observable parameters as possible using advanced simultaneous techniques, followed by incorporation of this multidisciplinary data into a unified theoretical framework.