<p>Exploring promising cathode materials is important for the development of zinc-ion batteries (ZIBs). In this work, the cubic spinel ZnMnO₃ material was prepared via a simple carbonate co-precipitation method, and the effect of sintering temperature (500, 600, 700, and 800 ℃) on the morphologies and electrochemical properties of ZnMnO₃ has been studied. Among the four samples, the ZnMnO₃ sample prepared at a sintering temperature of 600&#xa0;°C (ZMO113-600) exhibits the most uniform spherical morphology and the most excellent zinc storage performance. It delivers an initial discharge capacity of 184.7 mAh g⁻¹ at a current density of 0.2 A g⁻¹ and a reversible capacity of 118.6 mAh g⁻¹ after 300 cycles. Even at 1.0 A g⁻¹, it still provides a reversible capacity of 51.2 mAh g⁻¹. The ex situ XRD result exhibits that the ZMO113-600 has excellent structural stability during cycling. In addition, the zinc-ion diffusion coefficient for the ZMO113-600 electrode is in a range of 1.47 × 10⁻⁹–3.16 × 10⁻⁹ cm²&#xa0;s⁻¹. This work offers a promising avenue for the development of cost-effective and high-performance cathode materials for ZIBs.</p>