Is This New Potassium Metal Battery Design the Future of Energy Storage?

From cell phones, to solar power, to electric cars, humanity is increasingly dependent on batteries. As demand for safe, efficient, and powerful energy storage continues to rise, so too does the call for promising alternatives to rechargeable lithium-ion batteries, which have been the dominant technology in this space.

Led by Nikhil Koratkar, researchers from Rensselaer Polytechnic Institute have discovered a way to overcome a persistent challenge known as dendrites in order to create a metal battery that performs nearly as well as a lithium-ion battery, but relies on potassium — a much more abundant and less expensive element.

“In terms of performance, this could rival a traditional lithium-ion battery,” said Koratkar, an endowed professor of mechanical, aerospace, and nuclear engineering at Rensselaer.

While metal batteries have shown great promise, they have also traditionally been plagued by accumulation of metal deposits, called dendrites, on the anode. Over time, Koratkar explains, the conglomerates of potassium metal become long and almost branch-like.

If they grow too long, they will eventually pierce the insulating membrane separator meant to keep the electrodes from touching each other and shorting out the battery.

Koratkar and his team found that by operating the battery at a relatively high charge and discharge rate, they can raise the temperature inside the battery in a well-controlled manner and encourage the dendrites to self-heal off the anode.

The researchers previously demonstrated a similar method of self-healing with lithium metal batteries, but they found the potassium metal battery required much less heat to complete the self-healing process. That promising finding, Koratkar said, means a potassium metal battery could be more efficient, safe, and practical.

“I want to see a paradigm shift to metal batteries,” Koratkar said. “Metal batteries are the most efficient way to construct a battery; however, because of this dendrite problem they have not been feasible. With potassium, I’m more hopeful.”

This research, recently published in Proceedings of the National Academy of Sciences, is just the latest development in Koratkar's contributions to battery research. He is available to discuss a range of possible futures for energy storage.