Mango stone-like porous MnO@N‑C microplates with enhanced pseudocapacitive kinetics for high‑performance aqueous zinc‑ion batteries

Manganese monoxide (MnO) is an attractive cathode for aqueous zinc-ion batteries (ZIBs) but suffers from poor conductivity and sluggish kinetics. Herein, we report a porous N-doped carbon-coated MnO microplate composite (MnO@N-C) synthesized via an oxalate co-precipitation route combined with polydopamine coating and subsequent pyrolysis. The resulting material exhibits a distinctive mango stone-like microplate morphology (2 μm × 4 μm) with a high specific surface area of 220.9 m² g^{− 1} and abundant mesopores. The N-doped carbon shell enhances electronic conductivity while the porous architecture facilitates ion transport and induces significant intercalation pseudocapacitance. As a ZIBs cathode, MnO@N-C delivers a high discharge capacity of 190 mAh g^{− 1} at 0.1 A g^{− 1}, excellent rate capability (80 mAh g^{− 1} at 5 A g^{− 1}), and remarkable long-term cycling stability with 93% capacity retention after 2000 cycles at 2 A g^{− 1}. This work provides a straightforward morphological and compositional engineering strategy for developing high-performance MnO-based cathodes in aqueous ZIBs.