Electrochemical energy storage for renewable energy integration: zinc-air flow batteries
A 1 kW–4 kWh zinc-air flow battery has been built at Técnicas Reunidas facilities. The battery is divided in three different stacks connected in parallel, each of them comprising 20 cells connected in series and 0.25 m3 of electrolyte. The main challenges found on scaling up include the necessity of using three electrodes per cell, electrolyte leakage, ohmic resistance and gas diffusion electrode flooding. The three electrode solution is not optimal because it adds mechanical complexity and cost but it is a robust solution to evaluate the performance of the system as a baseline. During pilot plant operation, a phenomenon called shunt currents has revealed to reduce coulombic efficiency by 18%. In order to better understand this phenomenon, a mathematical model has been developed and it has been validated using real measurements taken on one of the 20-cell stacks. The major part of the challenges were solved and technical viability has been evaluated. However, efficiency, durability and the bifunctional air electrode are the challenges to overcome before this technology becomes ready for commercialization.
KeywordsZinc-air Flow battery Scale-up Energy storage Shunt currents Renewable energy integration
The LIFE ZAESS project is partially funded by the European LIFE Programme, Grant Agreement LIFE13 ENV/ES/001159.
- 1.IRENA (2017) Electricity storage and renewables: costs and markets to 2030. International Renewable Energy Agency, Abu DhabiGoogle Scholar
- 9.Price SWT, Thompson SJ, Li X, Gorman SF, Pletcher D, Russell AE, Walsh FC, Wills RGA (2014) The fabrication of a bifunctional oxygen electrodes without carbon components for alkaline secondary batteries. J Power Sources 259:43–49. https://doi.org/10.1016/j.jpowsour.2014.02.058 CrossRefGoogle Scholar
- 16.Konig S, Suriyah MR, Leibfried T (2015) Model based examination on influence of stack series connection and pipe diameters on efficiency of vanadium redox flow batteries under consideration of shunt currents. J Power Sources 28:272–284. https://doi.org/10.1016/j.jpowsour.2015.01.119 CrossRefGoogle Scholar