- A team of researchers have designed a new molten sodium battery system.
- The battery utilises less expensive materials.
- The researchers forecast that the battery will be market-ready in 10 years.
U.S. Department of Energy’s Sandia National Laboratories researchers have designed a new molten sodium battery class for grid-scale energy storage. The researchers said that “all the cascading cost savings” come with a drop in battery temperature. For example, this battery can use less expensive materials, the batteries require less insulation, and the wiring that connects the batteries can be thinner.
For the new molten sodium battery, the lead plate in a standard car lead battery is replaced by liquid sodium metal. The lead dioxide plate is replaced by a liquid mixture of sodium iodide and a small amount of gallium chloride. When energy is discharged from the new battery, the sodium metal produces sodium ions and electrons. On the other side, the electrons turn iodine into iodide ions. The sodium ions move across a separator to the other side, where they react with the iodide ions to form molten sodium iodide salt.
The researchers plan to continue working on the technology to refine the catholyte chemistry to replace the gallium chloride component as gallium chloride is expensive. The team is also working on tweaking the battery to charge and discharge faster and more fully.
The researchers add that it will likely take five to ten years to bring sodium iodide batteries to market. The development of the new sodium battery was supported by the Office of Electricity Energy Storage Program of the Department of Energy.