Solving the solvent problem

August 4, 2026 - 22:56

Researchers at MIT are making headway on a significant hurdle in energy storage: replacing lithium with sodium. Sodium is far more abundant and cheaper than lithium, which makes it an attractive option for large-scale battery systems that need to be affordable and easy to produce. But sodium metal is highly reactive, which has made it difficult to build a battery that lasts long and charges quickly without degrading.

The team's latest work focuses on the electrolyte, the liquid that carries charge between the electrodes. By carefully selecting the right electrolyte mixture, they found they could stabilize the sodium metal surface during cycling. This prevents the buildup of damaging deposits and keeps the battery functioning at high speeds. The result is a cell that can charge and discharge rapidly while maintaining its capacity over many cycles, a combination that has been hard to achieve with sodium before.

This discovery does not solve every problem with sodium batteries, but it addresses the core issue of reactivity. The researchers believe that with further tuning of the electrolyte chemistry, sodium metal batteries could become a practical option for grid storage and other applications where cost matters more than compact size. The work offers a clear path forward, showing that the solvent choice is not just a detail but a central lever for making sodium a viable partner to lithium.