New cathode design solves major barrier to better lithium-ion batteries
Researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have a long history of breakthrough discoveries with lithium-ion batteries. Many of these discoveries have focused on a battery cathode known as NMC, a nickel-manganese-cobalt oxide. Batteries with this cathode now power the Chevy Bolt.
The team at Argonne National Laboratory developed a method for producing boundary-free single crystals. Testing of small cells with such single-crystal cathodes at very high voltage showed a 25% increase in energy storage per unit volume, with almost no loss of performance over 100 cycles of testing. By contrast, over the same cycle life, the capacity declined by 60% to 88% in NMC cathodes composed of single crystals with many internal boundaries or with coated polycrystals.
“We now have guidelines that battery manufacturers can use to prepare cathode material that is boundary free and works at high voltage,” said Khalil Amine, an Argonne Distinguished Fellow. “And the guidelines should apply to other cathode materials besides NMC.”