MnCO ₃ /ZnMn ₂ O ₄ Composite for Aqueous Zinc Ion Storage

The aqueous zinc-ion battery is gradually becoming a research hotspot due to its low cost, high specific capacity, and safety. However, there are still problems such as the dissolution of Mn2+ during charging and discharging, structural collapse, and slow Zn2+ transport kinetics. This work aims to prepare a MnCO3/ZnMn2O4 (MO/ZMO) composite via a simple hydrothermal method combined with thermal treatment methods, which can effectively enhance the material’s adsorption capacity for Zn2+ and significantly promote Zn2+ diffusion kinetics and electrical conductivity, as also verified by density functional theory calculation. The synthesized MO/ZMO-0.10 electrode showed a reversible maximum specific capacity of 237 mAh g–1 at 100 mA g–1. Furthermore, it also delivered a specific capacity of 198.9 mAh g–1 after 100 cycles at 200 mA g–1. This study provides a composite design strategy for enhancing the electrochemical properties of MnCO3 materials.