In a groundbreaking study, researchers have unveiled a new understanding of the redox mechanism in high-energy batteries, potentially paving the way for more efficient and powerful energy storage solutions. The findings, published on arXiv, challenge conventional wisdom and could significantly impact the development of batteries for electric vehicles and other demanding applications.
For decades, scientists have grappled with the limitations of oxide-based cathodes, particularly their stability at high operating voltages. The most widely used cathode material, LiCoO2, has remained the gold standard despite extensive research into alternative materials. The reason? Researchers simply didn’t understand the fundamental redox mechanism at play.
Conventional theory suggested that redox reactions in these materials occur on cations at low voltages and on anions, specifically oxygen, at high voltages, forming oxidized chemical states like O2 or peroxo-species. However, this new study turns that theory on its head. Using a combination of in-situ and ex-situ spectroscopy and theoretical calculations, the researchers found that high-energy layered cathodes, such as LiCoO2 and LiNiO2, operate through the enhancement of negative charge transfer (NCT) ground states upon charging throughout the entire voltage range.
This means that NCT evolution is the intrinsic redox mechanism, regardless of the voltage range. NCT inherently involves high covalency and oxygen holes, leading to optimized performance without conventional redox centers. The level of NCT, or the number of ligand holes, explains many previously controversial results and provides a clear pathway toward developing viable high-energy battery electrodes.
This research is a game-changer for the energy industry. By redefining the redox mechanism, scientists can now focus on enhancing NCT to create more stable, high-energy-density batteries. This could lead to significant advancements in electric vehicle technology, renewable energy storage, and other applications that demand high-performance batteries.
The study is available on arXiv here:
Source: [arXiv](http://arxiv.org/abs/2509.20622v1)