Researchers at the University of California, Berkeley, have discovered a method that could see other metals used in place of cobalt in lithium-based batteries, as well as increasing their storage capacity.
In 2014, Ceder’s lab discovered a way that cathodes can maintain a high energy density without these layers, a concept called disordered rock salts. The new study shows how manganese can work within this concept, which is a promising step away from cobalt dependence because manganese is found in dirt, making it a cheap element.
“To deal with the resource issue of cobalt, you have to go away from this layeredness in cathodes,” Ceder said. “Disordering cathodes has allowed us to play with a lot more of the periodic table,” as quoted.
The technology could see manganese used in place of cobalt, reducing the world’s dependency upon the mineral that is largely mined in the copper belt in the Democratic Republic of Congo (DRC), Central African Republic and Zambia—with the DRC alone accounting for more than 50% of world production.
Using a process called fluorine doping, the scientists were able to incorporate a large amount of manganese in the cathode. Having more manganese ions with the proper charge allows the cathodes to hold more lithium ions and increase the battery’s capacity.
The disordered manganese cathodes approached 1,000 watt-hours per kilogram, with typical lithium-ion cathodes in the range of 500-700 watt-hours per kilogram.