Currently, the researchers said, the nation's electrical grid cannot tolerate large and sudden power fluctuations caused by wide swings in sunlight and wind, and must use batteries to bridge these fluctuations, storing excess energy and discharging it when input drops.
The best solution for intermittent grid storage today are "flow" batteries, which pump two different liquids through an interaction chamber where dissolved molecules undergo chemical reactions that store or give up energy through a membrane.
Existing flow batteries have two major drawbacks, scientists from the U.S. Department of Energy' SLAC National Accelerator Laboratory and Stanford University said -- the high cost of liquids containing rare materials such as vanadium, especially in the huge quantities needed for grid storage, and the membrane, which is also very expensive and requires frequent maintenance.
The new Stanford/SLAC battery design uses only one stream of molecules -- mostly inexpensive elements of lithium and sulfur -- and does not need a membrane at all, the researchers said.
"For solar and wind power to be used in a significant way, we need a battery made of economical materials that are easy to scale and still efficient," Stanford materials science Professor Yi Cui said. "We believe our new battery may be the best yet designed to regulate the natural fluctuations of these alternative energies."