Reduction‐Induced Oxygen Loss: the Hidden Surface Reconstruction Mechanism of Layered Oxide Cathodes in Lithium‐Ion Batteries (Adv. Energy Mater. 12/2025)

Lithium-Ion Batteries

In article number 2404193, Jongsoon Kim, Jihyun Hong, and co-workers reveal a hidden surface degradation mechanism in layered oxide cathodes for lithium-ion batteries. Reduction-induced side reactions at the cathode-electrolyte interface, such as rocksalt phase formation, oxygen loss, and electrolyte decomposition, occurring at a relatively high potential of ∼3 V (vs. Li/Li⁺) during lithiation are identified. This challenges the conventional view, which has focused solely on oxidation-driven degradation.