Fluorine-doped 3D Mn2O3 spheres as robust cathodes for high-performance aqueous zinc-ion batteries

The development of cathode materials with both high structural stability and superior specific capacity is crucial for advancing aqueous zinc-ion batteries (AZIBs). Manganese trioxide (Mn 2 O 3 ) has shown promise as a cathode material; however, its practical application is hindered by poor structural integrity and severe Mn dissolution during cycling, resulting in subpar electrochemical performance. To address these challenges, a fluorine (F) doping strategy was employed to enhance the stability of Mn 2 O 3 . F-doped Mn 2 O 3 (FMO) was synthesized via a hydrothermal method followed by high-temperature calcination. The effects of F-doping concentration on the material's structure and electrochemical behavior were systematically studied. The results reveal that F − partially substitutes lattice O 2− , increasing bond energy and reinforcing the [MnO 6 ] framework. This modification effectively reduces electrochemical polarization, enhances reaction kinetics, and improves charge/discharge reversibility. As a result, the Zn//FMO battery delivers an excellent specific capacity of 485.9 mAh g −1 at 0.1 A g −1 and maintains 125.9 mAh g −1 after 1000 cycles at 1.0 A g −1 . The findings demonstrate that F-doping is an effective strategy to overcome the intrinsic limitations of Mn 2 O 3 , offering a promising route toward high-performance AZIB cathodes.