Liquid metal batteries for storing renewable energy: MIT Professor Donald Sadoway named European Inventor Award 2022 finalist

• Electrochemist Donald Sadoway nominated for European Patent Office (EPO) innovation prize for batteries that have potential to revolutionize clean energy storage at scale
• Invention stores energy in molten metal and can help bring more wind and solar power onto the electricity grid – helping to move away from fossil fuels
• Liquid metal batteries overcome several drawbacks of lithium-ion batteries: they are fire-proof, made from locally sourced raw materials, and without precious metals, and retain 99% of their original capacity over 5.000 charging cycles

MUNICH, May 17, 2022 /PRNewswire/ -- The European Patent Office (EPO) announced today that Donald Sadoway, professor of materials chemistry at Massachusetts Institute of Technology (MIT), has been nominated as a finalist for the European Inventor Award 2022 for inventing a liquid metal battery that can bring more renewable energy onto the electricity grid.

Storing solar and wind power at scale would make it possible to use the clean power produced during the day at evening or morning peak load times, increasing the reliability of renewable energy and helping society move away from fossil fuels. Sadoway's rechargeable battery also degrades far less, meaning they have a longer lifespan than conventional energy storage solutions and can be manufactured with locally sourced raw materials.

"By enabling long-term storage of renewable energy, Sadoway's invention could help to solve a problem that many have battled for years to overcome," said EPO President António Campinos, announcing the European Inventor Award 2022 finalists. "His invention could reduce the cost of storing solar and wind power, providing consumers with more affordable and clean energy, with the potential to mitigate climate change in a sustainable manner."

Sadoway is named as one of the three finalists for the European Inventor Award in the "Non-EPO countries" category which recognises inventions developed outside European member states. The winners of the 2022 edition of the EPO's European Inventor Award will be announced at a virtual ceremony on 21 June.  

Extreme electrochemistry
Born in 1950 into a family of Ukrainian immigrants in Canada, Sadoway studied chemical metallurgy specialising in what he calls "extreme electrochemistry" – chemical reactions in molten salts and liquid metals that have been heated to over 500°C. After completing his PhD, he joined the faculty at MIT in 1978 and began to research new chemical processes for extracting metals from mining ores. He patented an alternative method for producing steel, an invention that he said opened his eyes to the thrilling practical implications of his research.

Fire-proof and built without lithium or cobalt
By the early 2000s, Sadoway was working on improvements to lithium-based batteries, which were becoming cheap and compact enough to use for consumer products. However, their shorter lifespan meant they were not suitable for the long-term storage of renewable energy. Sadoway realised he could combine his earlier knowledge in molten salts and liquid metals with his research on batteries to develop a more durable battery that could store energy at the scale needed by the electricity grid. Helped by a government grant, in 2009 Sadoway began working with a team of young researchers to develop the first rechargeable battery that stored electricity in layers of liquid metal separated by molten salt.

"Our liquid metal batteries work just like conventional batteries, only their components are all liquid," he says. "I use a low-density liquid metal on top, a high-density liquid metal on the bottom, and, in between, a molten salt. So you have two electrodes separated by an electrolyte, just like in a conventional battery."

Liquid metal batteries offer key competitive advantages over conventional batteries. Firstly, they can be built without lithium, cobalt or other metals subject to geopolitical constraints or exploitative practices, and can be made even from locally sourced minerals. They also degrade far more slowly which means long service lifetime and contain nothing combustible which means fire-proof.

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SOURCE The European Patent Office