Rechargeable Molten Salt Battery Freezes Energy in Place for Long-Term Storage

Fri, 06 May 2022 03:45:00 GMT
Scientific American - Technology

The technology could bring more renewable energy to the power grid

Researchers at Pacific Northwest National Laboratory, a Department of Energy national laboratory in Richland, Wash., are developing a battery that might solve this problem.

In a recent paper published in Cell Reports Physical Science, they demonstrated how freezing and thawing a molten salt solution creates a rechargeable battery that can store energy cheaply and efficiently for weeks or months at a time.

Most conventional batteries store energy as chemical reactions waiting to happen.

When the battery is connected to an external circuit, electrons travel from one side of the battery to the other through that circuit, generating electricity.

Some rechargeable batteries can lose almost a third of their stored charge in a single month.

Temperature fluctuations cause the battery to expand and contract, and the researchers had to identify resilient materials that could tolerate these changes.

The result is a rechargeable battery made from relatively inexpensive materials that can store energy for extended periods.

"What is so attractive about the freeze-thaw battery is that seasonal shifting capability," says Rob Roys, chief innovation officer at Launch Alaska, a nonprofit organization that works to accelerate the deployment of climate technologies in the state.

Even under mild conditions, the heating process requires energy equivalent to about 10 to 15 percent of the battery's capacity, Li says.

The batteries would be charged on-site, allowed to cool and driven to facilities called substations, where the energy could be distributed through power lines as needed.