Against an assumption that has prevailed in scientific communities for over eighty years, researchers at Oregon State University believe that potassium can be used to create a replacement for lithium-ion batteries. Chemist Xiulei Ji says that this possibility hasn’t been revisited since it was originally explored in 1932.
“For decades, people have assumed that potassium couldn’t work with graphite or other bulk carbon anodes in a battery,” said chemist Xiulei Ji, elaborating that he was surprised that the concept had been left uninvestigated for so long. In a paper published in the Journal of the American Chemical Society, Ji lays out his team’s process developing a potassium-graphite cell.
The possibilities that this could open up technologically are huge. Potassium is 880 times more abundant than lithium, which makes it a much cheaper alternative. If it could be successfully implemented as a replacement for lithium, we might see some significant price drops in devices that use lithium batteries, like smartphones.
However, if this revolution is to take place, the road ahead is rocky. Potassium atoms are far larger than lithium atoms, which makes it difficult to integrate with graphite. In order to achieve better results, the team wound up synthesizing a softer carbon material to replace graphite. Even with this enhancement, the team’s potassium-carbon batteries still aren’t as potent as lithium-carbon batteries.
“It’s safe to say that the energy density of a potassium-ion battery may never exceed that of lithium-ion batteries,” Ji 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.”
In short, potassium-ion batteries may never pack the punch-per-pound that lithium batteries do, but the reduced cost of using this cheaper element may make the shift worth it. Potassium isn’t the only ingredient currently striving to replace the problematically uncommon lithium. Researchers are also actively pursuing sodium and magnesium for this role as well.