Interfacial Designing of MnO₂ Half-Wrapped by Aromatic Polymers for High-Performance Aqueous Zinc-Ion Batteries

Due to the excellent specific capacity and high working voltage, manganese oxide (MnO₂) has attracted considerable attention for aqueous zinc-ion batteries (AZIBs). However, the irreversible structural collapse and sluggish ionic diffusion lead to poor rate capability and inferior lifespan. Herein, we proposed a novel organic/inorganic hybrid cathode of carbon-based poly(4,4′-oxybisbenzenamine)/MnO₂ (denoted as C@PODA/MnO₂) for AZIBs. Various in/ex situ analyses and theoretical calculations prove that PODA chains with C=N groups can provide a more active surface/interface for ion/electron mobility and zinc ion storage in the hybrid cathode. More importantly, newly formed Mn−N interfacial bonds can effectively promote ion diffusion and prevent Mn atoms dissolution, enhancing redox kinetics and structural integrity of MnO₂. Accordingly, C@PODA/MnO₂ cathode exhibits high capacity (321 mAh g⁻¹ or 1.7 mAh cm⁻² at 0.1 A g⁻¹), superior rate performance (88 mAh g⁻¹ at 10 A g⁻¹) and excellent cycling stability over 2000 cycles. Hence, rational interfacial designs shed light on the development of organic/inorganic cathodes for advanced AZIBs.