TU Graz researcher Stefan Spirk has found a way to replace liquid electrolytes in redox flow batteries with vanillin. Photo credits: © Lunghammer – TU Graz
Researchers at TU Graz have found a way to convert the aromatic substance vanillin into a redox-active electrolyte material for liquid batteries. The technology is an important step towards ecologically sustainable energy storage.
It is groundbreaking in the field of sustainable energy storage technology, ”says Stefan Spirk from the Institute for Bioproducts and Paper Technology at the Graz University of Technology. He and his team have succeeded in making redox flow batteries more environmentally friendly by replacing their core element, the liquid electrolyte, which mainly consists of ecologically harmful heavy metals or rare earths, with vanillin, an important component of Austrian vanilla croissants.
Sustainable energy storage
Vanillin, a commonly used flavor compound, is one of the few fine chemicals made from lignin. International research teams and companies have already proven that lignin may be suitable as a starting material for the production of electrolytes.
Would you like to commercialize the “green” redox flow technology developed at the Graz University of Technology: Dominik Wickenhauser, Dieter Wurm, Stefan Spirk, Wolfgang Bauer, Georg Rudelstorfer, Werner Schlemmer and Wolfgang Zitz (from left). Photo credits: © Lunghammer – TU Graz
Spirk and his team go one step further: “We refine lignin to vanillin into a redox-active material using a mild and green chemistry without the use of toxic and expensive metal catalysts, so that it can be used in flow batteries.” The process works at room temperature and can be carried out with common household chemicals. Vanillin is also found in abundance. “On the one hand, we can also buy it conventionally in the supermarket, on the other hand, we can also separate it from lignin by a simple reaction, which in turn is a waste product in paper production in large quantities. ”
Patenting and marketing
The separation and refining process was patented and the successful test results were published in the journal applied Chemistry. Now the researchers want to commercialize the technology, especially since the process is highly scalable and suitable for continuous production. Spirk explains: “We plan to connect our facility to a pulp mill and isolate the vanillin from the lignin that is left over as waste. What is not needed can then flow back into the regular cycle and be used energetically as usual. We are in concrete talks with Mondi AG, one of the world’s leading manufacturers of paper-based products, which is showing great interest in the technology. “
Tests at Graz University of Technology with a 3 kilowatt hour prototype and with vanillin-based electrolytes have proven the effectiveness of the new process. Photo credits: © Lunghammer – TU Graz
For the final implementation, the technology must be tested in real operation. The company is now looking for energy supply companies who can integrate the start-up’s redox flow technology into its infrastructure and thus relieve the grid. Spirk is convinced of its future success because: “We can maintain the value chain from the procurement of raw materials and components to regional power generation, enable storage capacities of up to 800 hundred MWh and reduce the load on the power grid and make an important contribution to storage green energy. Revolution.”
Liquid battery as part of the puzzle for the energy transition
Redox flow technology is an important piece of the puzzle for expanding renewable energies such as wind and solar energy, as it is characterized by the storage of large amounts of energy and can therefore cushion voltage peaks in the power grid. The batteries are also suitable as backup storage for stationary applications such as power plants, hospitals, mobile phone systems or e-filling stations. Redox flow batteries are more easily scalable, less toxic, more recyclable and more fireproof than lithium-ion batteries. Further essential advantages are the long life expectancy and the low self-discharge.
Reference: “2-methoxyhydroquinone from vanillin for aqueous redox flow batteries” by Werner Schlemmer, Dr. Philipp Nothdurft, Alina Petzold, Prof. Gisbert Riess, Philipp Frühwirt, Dr. Max Schmallegger, Prof. Georg Gescheidt-Demner, Prof. Roland Fischer, Prof. Stefan A. Freunberger, Prof. Wolfgang Kern and Prof. Stefan Spirk, August 20, 2020, Angewadte Chemie International Edition.
DOI: 10.1002 / anie.202008253
This research work is anchored in the subject areas “Sustainable Systems” and “Advanced Materials Science”, two of the five strategic research priorities of the Graz University of Technology.
The work was part of the research project “Lignobatt – Lignin in Redox Flow Batteries”, which was financed by the Climate and Energy Fund and carried out as part of the “Energy Research Program 2016 – New Technologies” of the Austrian research funding agency FFG. Project partners at Graz University of Technology were the Institute for Bioproducts and Paper Technology, the Institute for Chemistry and Technology of Materials and the Institute for Physical and Theoretical Chemistry. The team received external support from the chair for materials science and testing of polymers at the Montanuniversität Leoben and from Mondi.
