Low-cost and high-energy-density manganese-based compounds are promising cathode materials for rechargeable aqueous zinc-ion batteries (AZIBs), however, they often experience cycling instability issues and inferior rate capability. Herein, we report a new layered manganese-based cathode material, ZnMn₃O₇ (ZMO), which possesses a large interlayer spacing of 4.8 Å and allows the intercalation of ~1.23 Zn-ions per formula unit (corresponding to a capacity of ~170 mAh/g). Importantly, ZMO exhibits good cycling stability (72.9% capacity retention over 400 cycles), ultrafast-charging capability (73% state of charge in 1.5 min), and an ultrahigh power density (3510 W/kg at 88 Wh/kg). Through kinetic characterization, the favorable diffusion of ions and the dominant capacitor contribution are found to be conducive to the achievement of superior fast charging capability. Furthermore, the charge storage mechanism is revealed by ex-situ XRD and ex-situ XPS. This work may shed light on the design of high-performance electrode materials for AZIBs.