Synergistic Design of ZnCo-MnO@NPC Cathode and ZIF-8@Zn Anode for High-Performance Aqueous Zinc-Ion Batteries

Manganese-based cathodes offer high capacity, low cost, and safety for aqueous zinc-ion batteries (AZIBs), yet suffer from Mn dissolution, Jahn-Teller distortion, and sluggish Zn²⁺ kinetics. Herein, a Zn/Co co-doped MnO nanoporous carbon composite (denoted as ZnCo-MnO@NPC) derived from a bimetallic ZnCoMn metal-organic framework (ZnCoMn-MOF-74) is successfully synthesized and proposed as a high-performance cathode to address these challenges. The introduction of Zn²⁺ increases the initial specific capacity of MnO, while Co doping effectively suppresses the Jahn-Teller distortion and improves the integrity of the structure. Furthermore, the nanoporous carbon matrix facilitates electrolyte infiltration and accelerates ionic transport. To further suppress dendrite growth and enhance cycling stability, a zeolitic imidazolate framework (ZIF-8) protective layer is engineered on the zinc anode (denoted as ZIF-8@Zn), effectively mitigating dendrite formation. The ZnCo-MnO@NPC//ZIF-8@Zn full cell demonstrates superior electrochemical performance, delivering 281.3 mAh g^-1 at 0.1 A g^-1 and retaining 98.7% of this value after 3500 long-term cycles at 2.0 A g^-1, a remarkable finding that underscores its potential for high-performance energy storage. Collectively, this work highlights that transition metal ion doping represents an effective way to design efficient high-performance MOF-derived cathodes of AZIBs.