Researchers develop commercially viable salt batteries for safe energy storage
Researchers at the Swiss Federal Laboratories for Materials Science and Technology (Empa) are working on optimising salt batteries. Unlike lithium-ion batteries, these are non-flammable and can therefore be used in hazardous locations in mining or tunnelling as well as on oil and gas platforms.
Researchers from the Dübendorf-based Materials for Energy Conversion Laboratory of the Swiss Federal Laboratories for Materials Science and Technology(Empa) are continuing an Innosuisse project started by Ticino-based salt battery manufacturer Horien Salt Battery Solutions. The aim of the research collaboration is to develop economically attractive and usable salt batteries, according to a press release. Salt batteries are batteries in which the electrolyte is a solid, namely a ceramic ion conductor based on sodium aluminium oxide. The cathode is based on a granulate of common salt and nickel powder. The sodium metal anode is only formed during charging. Unlike conventional lithium-ion batteries, salt batteries are not flammable. They can therefore be used in areas where lithium-ion batteries are not permitted, such as in mining and tunnelling or on oil and gas platforms. Further advantages are their longevity and the significantly cheaper procurement of the raw materials. In contrast to the lithium-ion competition, the raw materials are cheap and available in large quantities, according to the press release.
One disadvantage of these batteries is their high operating temperature. To be ready for use, a salt battery requires a temperature of 300 degrees Celsius. The researchers are looking for options to make the applications more economical. “Depending on the application, it is more economical to keep a battery warm than to cool it,” Empa researcher Meike Heinz is quoted as saying in the press release.
Another endeavour is to operate the solid-state batteries nickel-free. The aim is to replace the cathode material nickel with other metals such as zinc. The aim is to establish salt batteries as long-term stationary storage systems thanks to their safety, long service life and the absence of critical raw materials.