While molten sodium batteries have been used for many years to store energy from renewable sources such as solar panels and wind turbines, commercially available molten sodium batteries, called sodium-sulphur batteries, typically operate at 270-350°C.
This new type of sodium battery operates at a much cooler 110°C, making it much cheaper to operate.
“We’ve been working to bring the operating temperature of molten sodium batteries down as low as physically possible,” said Leo Small, lead researcher on the project.
“There’s a whole cascading cost saving that comes along with lowering the battery temperature. You can use less expensive materials. The batteries need less insulation and the wiring that connects all the batteries can be a lot thinner.”
But the traditional sodium-sulphur battery chemistry doesn’t work at the lower temperature, so the team developed a ‘catholyte’, a liquid mixture of two salts, that enabled it to function normally.
“In our system...