Redox Flow Battery Materials for Energy Storage

As fossil fuel supplies dwindle and the climate change problem escalates, the need to harness renewable energy resources increases. However, these energy sources are intermittent and unpredictable, making them difficult to be used in a safe and stable power grid. For this reason, it is important that new energy storage technologies are developed which can shift energy from off-peak demand times to peak demand times. One of the most promising emerging technologies is the Redox Flow battery.

This project is focused on the investigation into increased performance and efficiency of redox flow batteries by improving their energy density. Furthermore, improving the energy storage efficiency and sustainability could potentially provide a solution in reducing inevitable costs that will occur when implementing a new energy storage technology.

One method of improving the energy density of Redox Flow Batteries is designing a better performing flow field. In Redox Flow Batteries, Redox couples are dissolved in electrolyte solutions and stored in separate reservoir tanks. During charge and discharge these electrolytes are pumped from reservoir tanks into half cells where they react in an electrode, either consuming or generating electrons. The more evenly the electrolyte is distributed through the electrode, the better the performance of the battery, this can be achieved by implementing a well-designed flow field. Throughout this project, different flow field designs will be designed using Computer Aided Design and evaluated using Computational Fluid Dynamics. These different flow field designs will then be manufactured and tested in the Laboratory.

As opposed to only testing laboratory scale cells, a kW scale cell closer to commercially available/ industrial cells will be developed. Findings based on experiments performed on laboratory scale test cells often do not correlate with industrial scale cells, making the design and manufacture of these larger cells vitally important. The manufacture of these cells also allows for investigation of different manufacturing processes (e.g. 3d printing) and materials which could reduce the cost of Flow Cell production.

In order to test other variables that effect the performance of Redox flow batteries, a parametric test cell will be investigated which would allow "on the fly" adjustments of parameters such as electrode compression, flow field dimensions and flow pattern amongst others. Using this cell, different electrode, membrane and gasket materials and electrolyte compositions could be compared under controlled conditions.
Using the insight gained from the parametric test cell and other cells tested, new experimental cell architectures will be evaluated in terms of performance and cost. A test cell with comparable performance to test cells with a traditional architecture but reduced production cost would provide other compelling areas for research and make redox flow batteries and even more viable option for large scale energy storage.