Towards a Greener Future
A 350% improvement in the discharge rate of flow batteries, achieved by two research groups in the Faculty of Mechanical Engineering and the Energy Program at the Technion
To a large extent, renewable energy sources depend on environmental conditions that are, over time, changing and uneven. These variables make it impossible to integrate them directly into the electricity grid, and necessitate an energy-storage system that mediates between them and the electricity grid. This presents one of the most significant challenges of our time: the development of energy-storage systems on a significant scale.
Today, flow batteries are considered to be one of the leading solutions for large-scale energy storage. In flow batteries, similar to lithium-ion batteries, an electric current is created as the result of an interaction between two materials, but the essential difference between them is that in flow batteries the materials are not solid and instead are constantly flowing.
A flow battery is a type of electrochemical cell in which chemical energy is provided by two chemical components dissolved in liquids that are then pumped through the system on separate sides of a membrane. Ion exchange accompanied by flow of electric current occurs through the membrane while both liquids circulate in their respective spaces. The most prominent advantages of flow batteries are a long life, safety, and the use of materials that do not pollute the environment. The problem is that the rate of energy release in these batteries is lower than the alternatives.
Now, a breakthrough from the Faculty of Mechanical Engineering and the Nancy and Stephen Grand Technion Energy Program at the Technion – Israel Institute of Technology could help address that problem. The study published in Flow: Applications of Fluid Mechanics was led by doctoral student Sofia Kuperman and Dr. Rona Ronen in the laboratories of Prof. Amir Gat and Prof. Matthew Suss.
Normal flow batteries have a primary flow channel. In the current study, the researchers added a secondary flow channel to the battery that is separated from the main channel by a perforated electrode. The secondary channel causes a flow to form from the main channel towards the electrode, and thus increases the number of interactions (the rate of battery discharge).
The main result of the study is that the innovative design of the flow battery makes possible a 350% faster energy discharge rate compared to the classic design of the flow batteries. The improvement suggested in the article is of great importance in speeding up the application process of flow batteries together with renewable energy sources and in reducing the carbon footprint resulting from emissions from burning fuels for the production of energy.
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