Electronegativity-Guided Dual-Anion Doping for Mn-O Bond Engineering To Boost Stability and Kinetics in Zinc-Ion...

Layered manganese oxide is a promising cathode material for rechargeable MnO₂//Zn batteries. Nonetheless, its commercial application is severely constrained by the structural instability and sluggish reaction kinetics of MnO₂ cathodes. To tackle these obstacles, this study proposes an electronegativity-guided dual-anion doping strategy, successfully synthesizing N/F codoped layered manganese oxide (N/F-MnO₂) through a facile hydrothermal approach. Low-electronegativity N doping facilitates the generation of Mn-N bonds, which weakens the strong interaction between Zn²⁺ and lattice oxygen, accelerating Zn²⁺ diffusion kinetics. In contrast, fluorine doping (high electronegativity) forms Mn-F bonds with high bonding energy, effectively enhancing structural stability. Meanwhile, NH₄⁺ ions and additional oxygen vacancies are introduced into the interlayer intervals and host structures of MnO₂, synergistically promoting Zn²⁺ migration and increasing zinc storage sites. Benefiting from the multimechanism coordination, the optimized N/F-MnO₂-2 cathode achieves a high discharge capacity of 496 mAh g^-1 at 0.1 A g^-1, showing a marked increase in comparison with K-MnO₂ (356 mAh g^-1). More impressively, it exhibits exceptional cycling durability, maintaining a capacity of 91.3 mAh g^-1 under 3 A g^-1 following 1000 cycles. This work not only provides an electronegativity-guided dual-anion doping approach for the engineering of advanced cathode materials but also offers valuable insights into high-performance AZIBs by multistrategy optimization.