Liquid metal batteries make Sadoway finalist for European award

Work could enable long-term storage of renewable energy

Elizabeth A. Thomson | Materials Research Laboratory
May 19, 2022

MIT Professor Donald Sadoway, a longtime supporter and friend of the Materials Research Laboratory, has been named a finalist for the 2022 European Inventor Award for his work on liquid metal batteries that could enable the long-term storage of renewable energy.

sadoway3Donald R. Sadoway, John F. Elliott Professor of Materials Chemistry

The annual award, conferred by the European Patent Office (EPO), “celebrates the genius and creativity of inventors for their contributions to technology, sustainability and economic growth, as well our daily lives,” according to the EPO.

Sadoway, the John F. Elliott Professor of Materials Chemistry in MIT’s Department of Materials Science and Engineering, is among 13 finalists for awards in five categories: Industry, Research, Non-European Patent Office countries, Small and Medium-sized Enterprises, and Lifetime achievement. In addition, the public selects a Popular Prize winner from the finalists by voting on the EPO website in the run-up to a virtual ceremony announcing all winners on 21 June 2022. 

Watch a video about Sadoway’s invention—and vote for him for the Popular Prize—at the following link.

Storing Renewable Energy

Storing solar and wind power at scale would make it possible to use the clean power produced by these sources at peak load times, increasing the reliability of renewable energy and helping society move away from fossil fuels. "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," says EPO President António Campinos.

"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."

In a press release announcing Sadoway as a finalist for the European Inventor Award, the EPO described his work as follows:

Extreme electrochemistry

Born in 1950 into a family of Ukrainian immigrants in Canada, Sadoway studied chemical metallurgy specializing 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 realized 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," says Sadoway. "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 a long service lifetime, and contain nothing combustible, which means they are fire-proof.

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