Rational Design of\nPorous Y<sub>2</sub>O<sub>3</sub>–MnO<sub><i>x</i></sub>/Carbon Heterostructures\nwith Abundant Oxygen Vacancies for High-Efficiency and Ultrastable\nZinc-Ion Storage

Manganese oxides have been considered as the most competitive\ncathode\nmaterials for aqueous zinc-ion batteries (ZIBs) on account of their\ninherent safety, high operating voltage, environmental friendliness,\nand cost-effectiveness. Unfortunately, the manganese dissolution,\ninherently poor electronic conductivity, and the sluggish reaction\nkinetics of commercial manganese-based oxides severely hinder their\npractical applications. To address the above issues, we creatively\ndeveloped hierarchical porous Y<sub>2</sub>O<sub>3</sub>–MnO<sub><i>x</i></sub>/C nanorods (named O<sub>V</sub>-YMO/C) with\nunique heterostructures and abundant oxygen vacancies via a facile\nMOF-assisted synthetic process and employed as the advanced cathode.\nOwing to the well-constructed porous structure, larger surface areas,\nabundant oxygen vacancies, and strong synergetic coupling effect at\nthe heterogeneous interface, the as-obtained O<sub>V</sub>-YMO/C cathode\nexhibited a fascinating discharge capacity of 389.6 mAh g<sup>–1</sup> at 0.1 A g<sup>–1</sup>. Simultaneously, it demonstrated\nremarkable rate performance (233 mAh g<sup>–1</sup> at 4.0\nA g<sup>–1</sup>) and cycling durability (90.6% capacity retention\nover 3000 cycles at 4.0 A g<sup>–1</sup>). The fabricated Zn//O<sub>V</sub>-YMO/C pouch cell could deliver superior flexibility and electrochemical\nstability under extreme bending conditions. Furthermore, the electrochemical\nreaction mechanism was comprehensively explored by kinetic analysis\nand density functional theory (DFT) calculations. The synergistic\nstrategy by subtly combining the MOF-assisted approach, heterojunction\nengineering, and oxygen defects engineering provides valuable insights\ninto the construction of cathode materials for high-rate and ultrastable\naqueous ZIBs.