Atomistic Origin of Transition-Metal Dissolution in Ni-Rich Cathodes: The Role of Oxygen Loss
Year: 2026
Type: preprint
Abstract: High-voltage operation of Ni-rich cathodes accelerates degradation through surface reconstruction and transition-metal dissolution. Although these processes occur concurrently, their mechanistic relationship remains unresolved. Here, we identify oxygen loss as the unifying mechanism coupling cathode surface reconstruction and transition-metal release in LiNi0.8Mn0.1Co0.1O2||graphite cells, consistent with the increased Ni deposition observed at the graphite anode. Surface-sensitive Ni L-edge X-ray absorption spectroscopy reveals that crossing the oxygen-loss threshold not only induces cathode surface reconstruction, but also progressively thins the reconstructed surface layer, evidenced by the evolution of signal attenuation. Ab initio molecular dynamics simulations corroborate this interpretation by showing that reconstructed-layer thinning originates from energetically favorable surface-layer detachment following oxygen-loss-driven destabilization of the near-surface lattice. Together, these findings establish oxygen loss as the mechanistic origin of coupled cathode degradation and transition-metal deposition, and identify stabilization of lattice oxygen as a key materials-engineering strategy to mitigate degradation and extend the cycling performance of next-generation Ni-rich Li-based energy storage devices.
Source: ChemRxiv
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223168861