An environmentally friendly, high-performance prototype of a rechargeable zinc-air battery was developed by researchers at the Faculty of Science and Technology of the University of Debrecen. The new type of energy storage uses cellulose-based, biodegradable materials as additives and membranes, the development is already in the scale-up phase.
The use of renewable energy and its storage possibilities have been researched for a long time by the staff of the Department of Applied Chemistry of the UD Faculty of Science and Technology.
We use many batteries, but their energy storage capacity is limited, which is a general barrier to the further spread of renewable energies. Today’s lithium batteries have several limitations that limit further development: their capacity is limited and their recyclability is difficult. Because of the latter, it is difficult to integrate it into the circular economy, which definitely limits the long-term economic and environmental goals. Research is ongoing to solve these difficulties of lithium-based systems and to replace lithium with other metals, such as our development, which uses zinc anode. Zinc-air batteries are also a special variant of this, since in addition to zinc being our anode, we obtain oxygen from the air in the cathode process
– explains Tibor Nagy, associate professor of the Department of Applied Chemistry of the UD Faculty of Science and Technology Institute of Chemistry, explaining the basis of the research.
Another advantage of the system is that it has a large theoretical capacity, according to the expert, based on all of these factors, it is one of the most promising alternatives to lithium-based batteries.
We didn’t just examine half a cell, which is often done in research, but put together a complete zinc-air system, which can be used as a battery on its own. This is how we made our prototype, which can be used to store electrical energy. The special feature of the system is that we simply used a zinc anode and an active carbon cathode, both of which are very cheap. Another advantage is that we did not use a catalyst, so there are no heavy metals in the prototype. Energy storage is realized on the cathode side with the help of oxygen extracted from the air
– adds Tibor Nagy.
Compared to traditional zinc-air systems, the prototype operates in a lower working voltage range, which allows the battery to work in much gentler conditions. As a result, they were able to achieve more stable operation, and harmful processes that reduced capacity and lifespan were pushed into the background.
There is zinc on the anode and there is no catalyst in the active carbon, so we do not use any catalyst. Again, this is good because it is simple and environmentally friendly. We use alkali as an electrolyte, which can be neutralized relatively easily. We only have one additive called carboxymethylcellulose, which is a cellulose-based polymer. So the wool jacket that separates the two electrodes and allows us to do electrical work with the battery is also of natural origin and environmentally friendly. In summary, our system is easy to produce, simple, cheap and easy to reuse, there are no problematic elements in it
– adds the researcher.
The specialist mentions the application of the appropriate geometry as a determining factor in the development process. After the design of the cells, 3D printing was chosen for this purpose, with which the geometry could be tested effectively and the cell body could be precisely formed.
In addition to the staff of the Department of Applied Chemistry of the UD Faculty of Science and Technology, specialists of the Solid State Physics Department also participated in the research. Several patent applications were filed during the research process.
Our prototype is ready, now in the scale-up phase, we are focusing on how to increase its performance in such a way as to keep the positive features. We are primarily working on increasing the capacity, but we have also connected the cells to increase the output voltage. The university’s Proof of Concept application contributes to this, which gives us the opportunity to develop a system with a significantly higher capacity
– says Tibor Nagy regarding the plans.
The researchers from Debrecen published the details and results of the research in the Journal of Energy Storage. With the study, Tibor Nagy won the Publication Award of the István Gróf Tisza Foundation for the University of Debrecen.
