Synergistic Engineering of Nonmagnetic Ions Enables Decoupling of Magnetic Frustration and Structural Dynamics in Cobalt-Free High-Nickel Cathodes.

Abstract

Cobalt-free high-nickel layered oxides have emerged as promising cathode candidates for next-generation lithium-ion batteries, owing to their exceptional capacity and cost-effectiveness. However, their large‑scale application remains constrained by intrinsic deficiencies stemming from cobalt absence-namely, magnetic‑ordering imbalance and sluggish structural dynamics. Here, a synergistic doping strategy involving nonmagnetic ions (B-Al-W) is presented to achieve atomic-scale coordination between bulk lattice stabilization (via Al/W doping) and near-surface interface passivation (through B enrichment). Precise substitution of non‑magnetic cations effectively mitigates magnetic frustration and superexchange interactions, while strengthened metal-oxygen bonding alleviates anisotropic lattice strain. Simultaneously, the constructed layered-spinel mortise and tenon structure significantly enhances Li⁺ diffusion kinetics. The optimized cathode material delivers a reversible capacity of 162.2 mAh g^-1 at 10 C, retains 88.6% capacity after 100 cycles at 5 C, and markedly suppresses voltage fade. This work provides a novel design paradigm for the synergistic magnetic-electrochemical regulation of Co‑free, high-Ni cathodes in next‑generation, high‑performance LIBs.