Lattice Chemistry Damping Stabilization Enables Voltage Stability and Oxygen Redox Reversibility in Li-Rich Layered Oxides

Abstract

Li-rich layered oxides (LLOs) are promising cathodes for high-energy-density Li-ion batteries, yet their practical deployment is hindered by severe voltage decay and structural degradation driven by uncontrolled lattice-oxygen activity. Here, we propose a lattice chemistry damping stabilization strategy by constructing radially graded disordered domains without disrupting the long-range layered order. The highly disordered surface evolves into spinel-like units with oxygen defects, functioning as a damping reservoir that buffers oxygen activity and accelerates Li+ diffusion, whereas the moderately disordered bulk acts as a structural damper by reinforcing TM–O bonding and alleviating strain. This spatially resolved cooperative damping enhances O 2p–TM 3d hybridization, promotes electron delocalization, and enables reversible oxygen redox. Importantly, in situ XRD and EIS–DRT jointly quantify this damping through suppressed Δc/ΔV and microstrain excursions, together with attenuated SOC-dependent polarisation/relaxation evolution under practical high-voltage operation. Benefiting from this mechanism, the optimized electrode delivers 81.3% capacity retention after 800 cycles with an ultra-low voltage decay of 0.64 mV/cycle, and Ah-level pouch cells maintain 90% capacity after 200 cycles alongside negligible voltage decay. This work provides a physically inspired, measurement-anchored pathway to suppress voltage decay and extend the lifetime of LLOs.