A New High-Performance Porous Carbon-Coated MnO/NaCO Cathode for Suppressing MnDissolution in Aqueous Zinc Ion Batteries.

Manganous-manganic oxide (MnO), akin to other manganese-based oxides, faces several critical challenges such as substantial capacity fading and limited rate performance due to its inferior electrical conductivity, in addition to the inevitable dissociation of Mn. To address these issues, we introduce for the first time a novel carbon-coated MnO/NaCO (MnO/NaCO/C) composite material. Comprehensive characterizations indicate that NaCO effectively curtails Mndissolution, enhances carbon encapsulation throughout charging/discharging cycles, and exposes additional active sites on the MnO/NaCO/C composite. Electrochemical assessments confirm that the MnO/NaCO/C-2 cathode exhibits exceptional electrochemical performance, outperforming other cathodes in the ZnSO system. Moreover, the MnO/NaCO/C-2 cathode delivers a high specific capacity of ~550 mAh g at 0.1 A g and maintains a significant capacity of ~230 mAh g after 360 cycles at 1.0 A g within the 2.0 M ZnSO+0.2 M MnSO electrolyte system, demonstrating its potential as a high-performance cathode material for aqueous zinc-ion batteries.