A research team, supported by the Swiss National Science Foundation (SNF), has produced experimental battery components based on sodium and magnesium to provide alternatives to the current lithium batteries.
The recent research, led by Arndt Remhof of the Swiss Federal Laboratories for Materials Science and Technology (Empa), aims to find new materials that can be used in rechargeable batteries and eventually tackle problems existing in lithium batteries, such as the limited availability of the raw material itself as well as the inflammability and other safety issues.
Swiss researchers have developed solid-state battery cells, the design of which poses a significant technical problem. Ions — whether they are lithium, sodium or magnesium — must be allowed to move through a solid medium.
To facilitate the displacement of ions, the researchers developed solid electrolytes with crystalline structure. They completely overhauled the crystalline architecture of the materials and used new components and manufacturing processes.
Sodium ions were able to move around easily in the new sodium-based compound at 20℃. The electrolyte is also non-flammable and chemically stable up to 300℃, the SNF said in a statement.
The low-cost possibilities of sodium and its stability could address the safety concerns of lithium batteries, scientists said.
The same team also developed a solid magnesium-based electrolyte and stimulated the movement of magnesium ions at 70℃, which is a much lower temperature than in earlier research.
The advantage of magnesium is its vast abundance and the fact that it is light and poses no risk of explosion. As a magnesium ion has two positive charges, compared with one for lithium, a magnesium battery can store almost twice as much energy for the same volume, said the project leaders.
Elsa Roedern of Empa, who led the experiments, said, “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.”