Researchers from the U.S. National Accelerator Laboratory and Stanford University have develpoed a new type of flow battery which could potentially provide low-cost, long-life storage for solar and wind energy.

Current flow batteries pump two different liquids through an interaction chamber where dissolved molecules undergo chemical reactions that store or release energy. The chamber contains a membrane that only allows ions which are not involved in reactions to pass between the liquids.

Flow batteries are among the most promising technologies for grid storage because they include tanks, pumps and pipes which are easily scaled up to whatever size is required.

However, current flow batteries are expensive because the liquid reactants, which are needed in large quantities for grid storage, include costly, rare materials. The membranes are also expensive and require frequent maintenance.

In the new battery design, the reactants are mostly lithium and sulfur, which are relatively inexpensive. These interact with lithium metal coated with a barrier that permits electrons to pass without degrading the metal. The entire molecular stream is dissolved in a non-corrosive organic solvent. The design does not need a membrane at all.

In the video, Stanford graduate student Wesley Zheng demonstrates the principle of the new batteries.