In Situ Metal–Organic Framework-Derived MnO/C Nanoparticles Interlocked with 3D Carbon Nanotubes for High-Performance Zinc-Ion Batteries

Aqueous zinc-ion batteries (ZIBs) are promising appealing technologies for energy storage because of their cost-effectiveness, high safety, and environmental benignancy. Achieving superior performance in ZIBs mainly depends on further advancement of cathodes. MnO possesses desirable theoretical capacity and affordability, but it is hampered by inadequate electronic conductivity and insufficient structural stability upon cycling. In this study, a MnO/C@CNTs composite is fabricated through the in situ epitaxial growth of Mn-MOF-74 on carbon nanotubes (CNTs) followed by controlled pyrolysis. The resulting architecture features MnO/C nanoparticles firmly anchored within a highly conductive three-dimensional (3D) CNT network facilitated by interfacial Mn-O-C bonding. This unique framework significantly enhances electronic transport and mechanical stability, leading to an outstanding electrochemical performance. MnO/C@CNTs thus achieves the capacity of 403.2 mAh g^-1 at 0.3 A g^-1, with 153.5 mAh g^-1 retention even when the current is as high as 4.0 A g^-1. Remarkably, it also displays exceptional durability, as evidenced by the retention level of 69.6% after 5000 cycles at 4.0 A g^-1. The above results outline an effective approach for designing advanced manganese-centric cathodes with high capacity for ZIBs.