Highly conductive manganese sesquioxide/Nitrogen-doped reduced graphene oxide composite for aqueous rechargeable zinc-ion batteries cathode

Compared to lithium-ion batteries, aqueous rechargeable zinc-ion batteries (ZIBs) are of interest for their high safety and low cost. Manganese-based oxide materials as an attractive cathode candidate for ZIBs However, the low conductivity of manganese oxide materials leads to poor electrochemical performance. Herein, manganese sesquioxide/Nitrogen-doped reduced graphene oxide (Mn 2 O 3 /N-rGO) composite has been synthesized by hydrothermal method. The Mn 2 O 3 /N-rGO composite as ZIBs cathode material provides high electrical conductivity, which facilitates charge transfer and improves the overall electrochemical performance. The electrode provides 222.3 mA h g −1 of high reversible capacity with a current density of 100 mA g −1 . A robust cycle stability with over 90% of initial capacity retained and 98% coulombic efficiency was observed following 500 cycles. Its excellent electrochemical behavior can be explained by the higher electrical conductivity, faster Zn 2+ transfer, and stronger structural stability of N-rGO. In addition, the energy storage mechanism of H + and Zn 2+ coinsertion was also tentatively studied, which provides inspiration for future design and research on high-performance manganese-based materials cathodes of ZIBs. Graphical Abstract