Ubiquitous as they may be, lithium-ion batteries are known to have some problems. One such issue is that the cathode in these batteries can generate excess oxygen, which reacts with the electrolyte. That forms a film on the cathode surface, which reduces the amount of energy that can be passed between the two, in turn reducing the performance of the whole battery.
To counter that problem, the cathodes in most lithium-ion batteries have special coatings that reduce the effect. Unfortunately, this slows down lithium ions passing in and out, decreasing efficiency. Plus, because the coating doesn’t cover the entire surface, the degradation can still occur when the battery is operating at a higher temperature or voltage.
For the new study, researchers at Argonne National Laboratory and Hong Kong University of Science and Technology (HKUST) investigated alternative coatings, to help these batteries last longer.