Abstract
ABSTRACTLayered manganese dioxide (δ‐MnO2) is a promising cathode material for aqueous zinc‐ion batteries (AZIBs) due to its high theoretical capacity, high operating voltage, and low cost. However, its practical application faces challenges, such as low electronic conductivity, sluggish diffusion kinetics, and severe dissolution of Mn2+. In this study, we developed a δ‐MnO2 coated with a 2‐methylimidazole (δ‐MnO2@2‐ML) hybrid cathode. Density functional theory (DFT) calculations indicate that 2‐ML can be integrated into δ‐MnO2 through both pre‐intercalation and surface coating, with thermodynamically favorable outcomes. This modification expands the interlayer spacing of δ‐MnO2 and generates Mn–N bonds on the surface, enhancing Zn2+ accommodation and diffusion kinetics as well as stabilizing surface Mn sites. The experimentally prepared δ‐MnO2@2‐ML cathode, as predicted by DFT, features both 2‐ML pre‐intercalation and surface coating, providing more zinc‐ion insertion sites and improved structural stability. Furthermore, X‐ray diffraction shows the expanded interlayer spacing, which effectively buffers local electrostatic interactions, leading to an enhanced Zn2+ diffusion rate. Consequently, the optimized cathode (δ‐MnO2@2‐ML) presents improved electrochemical performance and stability, and the fabricated AZIBs exhibit a high specific capacity (309.5 mAh/g at 0.1 A/g), superior multiplicative performance (137.6 mAh/g at 1 A/g), and impressive capacity retention (80% after 1350 cycles at 1 A/g). These results surpass the performance of most manganese‐based and vanadium‐based cathode materials reported to date. This dual‐modulation strategy, combining interlayer engineering and interface optimization, offers a straightforward and scalable approach, potentially advancing the commercial viability of low‐cost, high‐performance AZIBs.
Published Version
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