The belief that potassium cannot work with graphite or other bulk carbon anodes in a battery has been overturned, with findings at Oregon State University, following a study led by have Xiulei (David) Ji, assistant professor of chemistry in the College of Science at Oregon State University.

A potassium-ion battery has been shown to be possible. “For decades, people have assumed that potassium couldn’t work with graphite or other bulk carbon anodes in a battery,” said Ji. “That assumption is incorrect,” he continues.

The Journal of the American Chemical Society published the findings from this discovery, which was supported by the US Department of Energy and done in collaboration with OSU researchers Zelang Jian and Wei Luo. A patent is also pending on the new technology which could result in a battery based on materials that are far more abundant and less costly.

The findings open alternatives to batteries that can work with well-established and inexpensive graphite as the anode, or high-energy reservoir of electrons. Lithium can do that, as the charge carrier whose ions migrate into the graphite and create an electrical current.

Aside from working with a carbon anode, lithium is found in only 0.0017% by weight, of the Earth’s crust, making it comparatively expensive. It is also difficult to recycle. Researchers have yet to duplicate its performance with less costly and more readily available materials, such as sodium, magnesium, or potassium.

Potassium is 880 times more abundant in the Earth’s crust than lithium and could work effectively with graphite or soft carbon in the anode of an electrochemical battery. Presently, batteries based on this approach do not have performance that equals those of lithium-ion batteries, but improvements in technology should narrow the gap, Ji said.

“It’s safe to say that the energy density of a potassium-ion battery may never exceed that of lithium-ion batteries,” he said. “But they may provide a long cycling life, a high power density, a lot lower cost, and be ready to take the advantage of the existing manufacturing processes of carbon anode materials.”

Electrical energy storage in batteries is essential not only for consumer products such as mobile phones and computers, but also in transportation, industry power backup, micro-grid storage, and for the wider use of renewable energy.

The university is seeking support for further research and to help commercialise the new technology.