A New High-Performance Porous Carbon-Coated Mn3O4/Na2CO3 Cathode for Suppressing Mn 2+ Dissolution in Aqueous Zinc Ion Batteries.

Abstract

Manganous-manganic oxide (Mn3O4), 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 2+ . To address these issues, we introduce for the first time a novel carbon-coated Mn3O4/Na2CO3 (Mn3O4/Na2CO3/C) composite material. Comprehensive characterizations indicate that Na2CO3 effectively curtails Mn 2+ dissolution, enhances carbon encapsulation throughout charging/discharging cycles, and exposes additional active sites on the Mn3O4/Na2CO3/C composite. Electrochemical assessments confirm that the Mn3O4/Na2CO3/C-2 cathode exhibits exceptional electrochemical performance, outperforming other cathodes in the ZnSO4 system. Moreover, the Mn3O4/Na2CO3/C-2 cathode delivers a high specific capacity of ~550 mAh g -1 at 0.1 A g -1 and maintains a significant capacity of ~230 mAh g -1 after 360 cycles at 1.0 A g -1 within the 2.0 M ZnSO4+0.2 M MnSO4 electrolyte system, demonstrating its potential as a high-performance cathode material for aqueous zinc-ion batteries.