Nickel is already used in lithium-ion batteries, but increasing the proportion of nickel could significantly improve battery energy density, making them especially suitable for electric vehicles and grid-scale storage. However, practical applications for these materials have been limited by structural instability and the tendency to lose oxygen atoms, which cause battery degradation and failure.
The researchers, led by the University of Cambridge and the University of Birmingham, found that ‘oxygen hole’ formation – where an oxygen ion loses an electron – plays a crucial role in the degradation of nickel-rich battery materials. These oxygen holes accelerate the release of oxygen that can further degrade the battery’s cathode, one of its two electrodes. Their results are reported in the journal Joule.
Using a set of computational techniques on UK regional supercomputers, the researchers examined the behaviour of nickel-rich cathodes as they charged. They found that during charging, the oxygen in the material undergoes changes while the nickel charge remains essentially unchanged.
Read more at: University of Cambridge
Photo credit: bixusas via Pixabay