Researchers at TU Graz – Technical University of Graz – have found a way to convert the aromatic substance vanillin into a redox electrolyte for liquid batteries. Technology is an important step towards sustainable energy storage. The research results are published by the journal Angewandte Chemie International.
“This is a breakthrough in sustainable energy storage technology,” said Stefan Spirk of the Institute for Bio-Products and Paper Technology at the Graz University of Technology, Austria. He and his team have succeeded in making redox batteries more environmentally friendly by replacing their main cell, a liquid electrolyte, which is mainly composed of environmentally harmful heavy metals or rare earths, with vanillin, an important ingredient in Austrian vanilla croissants.
Vanillin, commonly used as an aromatic compound, is one of the few fine chemicals produced from lignin. Lignin is a substance that characterizes the stiff walls of plant cells. A complex polymeric compound found in the cells of vascular plants and some algae.
Spirk and his team convert the lignin to vanillin and then to a redox material using mild and green chemistry without the use of toxic and expensive metal catalysts. It can even be used in flowing batteries. The process works at room temperature and can be carried out using ordinary household chemicals. Vanillin is also readily available.
The separation and refining process is already patented.
Researchers now want to commercialize the technology, especially since the process is highly scalable and suitable for continuous production. “The plan is to connect our mill to a pulp mill and isolate vanillin from the lignin that remains as waste. Everything that is not needed can subsequently return to the normal cycle and be used in the energy sector as usual. We are in specific negotiations with Mondi AG, a leading global paper manufacturer that has a strong interest in this technology, ”concludes Spirk.
It is worth noting that flow-through redox batteries are easier to scale, less toxic, more recyclable, and more fireproof than lithium-ion batteries. Other important advantages are their high operating time and low self-discharge.