Adaptive lattice breathing enabled by Cu/Mg co-doping for stable anionic redox chemistry in sodium layered oxides.

ABSTRACT: Advancing the energy density of sodium-ion batteries requires layered oxide cathodes with higher specific capacity, necessitating redox chemistry beyond conventional cations. Oxygen anionic redox offers a pathway but presents inherent challenges, including irreversible structural degradation, such as Jahn-Teller distortion. Here, we report that cooperative Cu/Mg co-doping triggers an adaptive lattice respiration mechanism that concurrently suppresses structural distortion and unlocks highly reversible anionic redox. Through in situ spectroscopy, we visualize that this dynamic process involves the oxidation of Cu²⁺ to Jahn-Teller inactive Cu³⁺, which induces a predictable lattice distortion, while Mg²⁺ orchestrates a compensatory symmetric breathing o

SUBMITTER: Zhang Z 

PROVIDER: S-EPMC12766739 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature