Worldwide renewable energies like wind and solar are rapidly replacing fossil fuels for electricity generation. But these renewable energies cannot always consistently produce energy. So, we require widespread energy storage for speeding the transition to a carbon-free power grid.
Now scientists at the US Department of Energy’s Pacific Northwest National Laboratory (PNNL) have come up with the solution. They have developed a new type of molten “freeze-thaw” battery that can hold energy for several months without losing charge.
Researchers have created an aluminum-nickel molten salt battery that exhibits high retention of cell capacity over periods of weeks
Minyuan Miller Li, a battery scientist at PNNL who led the research said, “It’s a lot like growing food in your garden in the spring, putting the extra in a container in your freezer, and then thawing it out for dinner in the winter,”
In this battery, an aluminum anode and a nickel cathode were immersed in a molten-salt electrolyte. The battery has an energy density of 260 W/hour per kg which is higher than today’s lead-acid and flow batteries.
The prototype is small; it is about the size of a hockey puck
But the researchers foresee that the potential usefulness of the device is vast.
“You can start to envision something like a large battery on a 40-foot tractor-trailer parked at a wind farm,” said co-author Vince Sprenkle, senior strategic advisor at PNNL. “The battery is charged in the spring, and then the truck is driven down the road to a substation where the battery is available if needed during the summer heat.”
The study was published in the journal Cell Reports Physical Science.