Unveiling the action mechanism of synergistic d/p-band center modulation on the zinc storage capability of industrial-grade MnO₂ cathode

Sluggish reaction kinetic, high-energy barrier and poor structural stability lead to rapid capacity decay and terrible self-charging properties, becoming major obstacles in using industrial-grade manganese dioxide (MnO₂) as a cathode in aqueous zinc-ion batteries (AZIBs). To address this challenge, we herein report a d/p-band center-modulated MnO₂ via a facile mechanical ball-milling method using industrial-grade MnO₂ as the precursor. Systematic characterization and theoretical calculations reveal that oxygen vacancy (O_v) serves as favorable adsorption sites, synergistically strengthening the interfacial stability for both Zn²⁺ and H⁺ ions. Critically, the structural defect substantially reduces migration barriers, facilitating solid-state Zn²⁺ diffusion within the MnO₂ lattice and enabling ultrafast Grotthuss-type proton transport. Furthermore, the modified electronic structure around O_v effectively suppresses Jahn-Teller distortions and mitigates cyclic lattice strain, thereby inhibiting irreversible phase transformation. The d/p-band center modulated MnO₂ delivers a high initial discharge capacity of 339.7 mAh·g^–1 at 0.2 C. Remarkably, it achieves a capacity retention of 98.7% after 700 cycles at 2 C, substantially outperforming its pristine counterpart. This work provides atomic-level insights into the role of O_v in enhancing electrochemical performance, thereby establishing a rational design principle for transforming industrial-grade MnO₂ into high-performance AZIBs cathodes.