Liquid, molten batteries as energy aid?

CAMBRIDGE, Mass., Feb. 14 (UPI) -- U.S. researchers say giant liquid batteries could eventually level the load from intermittent renewable energy sources such as solar or wind.

The drawback to many such alternative energy sources is that they are not continuous, the researchers say; the sun doesn't always shine and the wind doesn't always blow.

Scientists at the Massachusetts Institute of Technology are looking at a promising technology that could provide the long-sought way of leveling the load by storing energy until it is needed, at far lower cost and with greater longevity than previous methods, an MIT release reported Tuesday.

The system uses extremely high-temperature batteries whose liquid components naturally settle into distinct layers because of their different densities.

The three molten materials form the positive and negative poles of the battery as well as a layer of electrolyte -- a material charged particles migrate through as the battery is being charged or discharged -- in between.

The materials for all three layers are abundant and inexpensive, Donald Sadoway said.

"We explored many chemistries," Sadoway said, citing one such combination of magnesium for the negative electrode (top layer), a salt mixture containing magnesium chloride for the electrolyte (middle layer) and antimony for the positive electrode (bottom layer).

The system would operate at a temperature of 1,292 degrees Fahrenheit, he said, and would smooth out the erratic supplies of solar or wind-generated electricity.