Double carbon layer matrix synergistically improved the zinc-ion storage performance of manganese oxide

Abstract

Aqueous zinc-ion batteries (AZIBs) have become a hot topic in study owing to their abundance of zinc resources, environmental friendliness, high capacity, and low cost. Nevertheless, the majority of cathode materials utilized in AZIBs frequently exhibit suboptimal electrical conductivity and structural instability, which restrict their application in energy storage. Here, a carbon-coated manganese oxide anchored on carbon skeleton (MnO–C@C) hybrid was synthesized using a simple and scalable method. The electrical conductivity of MnO can be enhanced by the double carbon layer. The presence of carbon skeleton effectively inhibits the agglomeration phenomenon of MnO and exposes more active sites. Meanwhile, the interaction force between the coated carbon and MnO effectively increases the structural stability of MnO. Taking advantage of the synergistic effect, the MnO–C@C hybrid shows an exceptional specific capacity of 409 mAh g−1 at 50 mA g−1 and outstanding cycling stability of 1000 cycles at 2000 mA g−1 (low decay rate of 0.0058 % per cycle). Besides, the reaction mechanisms are investigated via various characterizations. This work presents an inspired solution for developing manganese-based cathode materials in AZIBs.