Recent research led by Arndt Remhof of the Swiss Federal Laboratories for Materials Science and Technology (EMPA) is said to have demonstrated the potential of sodium and magnesium and his team has produced experimental battery components based on these metals.
Remhof’s team has developed a solid electrolyte that allows good mobility of sodium ions at 20°C. The electrolyte is also said to be non-flammable and chemically stable at temperatures of up to 300°C, which addresses the various safety concerns associated with lithium-ion batteries. Meanwhile, a team at the University of Geneva, led by Professor Hans Hagemann, has been working in parallel to develop cheaper methods of producing the new solid electrolyte.
“Availability is our key argument”, says EMPA researcher Léo Duchêne. “However, sodium stores less energy than the equivalent mass of lithium and thus could prove to be a good solution if the size of the battery isn’t a factor for its application.”
The same team has also developed a solid magnesium-based electrolyte, citing its abundance, light weight and no risk of explosion. However, because a magnesium ion has two positive charges, it can store almost twice as much energy in the same volume as lithium.
But higher temperatures are needed to get suitable mobility – the lowest temperature achieved so far is 70°C. EMPA’s Elsa Roedern noted: “We are still a long way from having a complete and functional prototype, but we have taken the first important step towards achieving our goal.”
