Science Share on Facebook Share on Twitter Share on Pinterest Share on LinkedIn Sodium’s energy density is lower than lithium’s, but it is nonetheless a promising alternative for battery applications thanks to its relative abundance and lower cost. The difficulty is that only a few materials conduct sodium ions well enough to make good electrolytes. Researchers are thus keen to identify new solid electrolytes in which the ions diffuse quickly and understanding the mechanisms responsible for this diffusion is a key step in that process. Strongly anharmonic phonon modes Led by Olivier Delaire, the Duke researchers used neutron scattering experiments at the Oak Ridge National Laboratory to study one possible electrolyte, sodium thiophosphate (Na3PS4). The crystal structure of this material was known to create a one-dimensional tunnel for sodium ions, but the new work showed that the pyramid-shaped phosphorus-sulphur PS4 units that frame the tunnels also twist and turn. This motion gives rise to strongly anharmonic phonon modes that act like paddlewheels, helping the sodium ions move through the material by allowing them to “hop” along minimum energy pathways. Sandwich strategy makes solid-state lithium battery last longer While this process had been predicted by theory, the results of Delaire and colleagues show that it is much more complex than previously thought – something that they confirmed using ab initio molecular dynamics and extended molecular dynamics calculations at the National Energy Research Scientific Computing Center. In their calculations, the Duke team used a machine learning algorithm to analyse the potential energy surface in which the atoms vibrate and move. The researchers say their results, which they describe in Energy & Environmental Science, provide a microscopic understanding of how atomic vibrations facilitate the diffusion of sodium ions through the material. They are now studying a slightly different version of their material that contains antimony instead of phosphorus. Share on Facebook Share on Twitter Share on Pinterest Share on LinkedIn Products You May Like Ads by AmazonArticles You May Like Movie Review: ‘One of Them Days’ 2025 Asian Film Awards Nominations: Full List Kumite, Brittany Howard’s new hardcore band, played their first show in Nashville Timothée Chalamet and Glorilla Announced as Saturday Night Live Musical Guests The best smart speakers for 2025