MIT researchers have developed a machine-learning pipeline to identify electrolyte solvents for sodium-metal batteries, publishing their findings in the journal Joule on August 4, 2026.
The project was led by Ju Li, professor of power engineering in MIT’s departments of Nuclear Science and Engineering and Materials Science and Engineering. Sodium is roughly 1,000 times more abundant than lithium and costs about one-hundredth as much per pound, but sodium metal is highly reactive. Electrolytes frequently undergo side reactions with the electrodes, forming insoluble barrier compounds that block ion transport and shorten battery life.
Building on a 2021 discovery of a sulfonamide solvent called DMTMSA that stabilized lithium batteries, the 15-member team searched for smaller related molecules. Smaller solvent molecules allow sodium ions to move faster between electrodes, enabling faster charging and discharging rates.
Molecules Screened by AI
Chia-Wei Hsu, an MIT PhD student in materials science and engineering, created an AI-guided algorithm that generated 100,000 candidate molecules in 24 hours. Hsu narrowed the selection to 200 candidates based on shape similarity to DMTMSA and electronic properties. The researchers selected 27 candidates for experimental testing under identical conditions.
Weiyin Chen, a postdoc in Nuclear Science and Engineering and one of four lead authors, reported that a solvent called DMFSA proved to be the smallest and best candidate. The team is now conducting a follow-up search using DMFSA as the starting point to discover even smaller solvent molecules.
Jinhyuk Lee, an associate professor at McGill University who was not involved in the study, said the design strategy could influence future energy storage technologies beyond sodium systems.
Funding for the research came in part from a National Research Foundation of Korea grant and a U.S. National Science Foundation graduate research fellowship. Equipment for characterization was provided in part by the MIT.nano Characterization Facilities.
