Redox flow batteries, as promising candidates for grid-scale energy storage, have recently attracted a great wealth of research interests. Capital costs, however, are still hindering large-scale commercialization of redox flow batteries, within which chemical cost plays an important role. To reduce chemical costs, the promotion of utilization ratios of active materials (chemical fuels) in current redox flow batteries is a possible solution, which could potentially further lower the cost of the whole system.
In this presentation, we report such efforts from our lab on two redox flow batteries: the all vanadium and zinc iodide systems. Through optimizations of electrolyte components and re-design of flow chemistry, utilization ratios of active materials, as well as specific volumetric capacities, are significantly enhanced in these systems.