Magnetic field-assisted synthesis of Co-doped Mn3O4/MnOOH multiphase manganese oxides for high-performance cathodes in aqueous rechargeable zinc-ion batteries

Manganese-based oxides, recognized as suitable cathode materials for aqueous zinc-ion batteries (AZIBs), often face challenges in cycling stability and rate performance due to poor electronic conductivity and slow ion migration rates. In this study, we synthesized Co-doped Mn 3 O 4 /MnOOH materials using a straightforward magnetic element induction method. The cobalt incorporation significantly alters the microstructure of MnOOH, creating a multiphase manganese oxide system that enhances electron transportation and accelerates charge transfer rates. This improvement not only boosts zinc storage capacity but also mitigates the Jahn-Teller distortion associated with Mn 3+ during electrochemical reactions, enhancing both cycling stability and energy storage capacity. The charge storage mechanism of Co-Mn 3 O 4 /MnOOH, identified as Zn 2+ /H + co-insertion, was confirmed through ex-situ X-ray diffraction and X-ray photoelectron spectroscopy. Impressively, Co-Mn 3 O 4 /MnOOH achieves a specific capacity of 310.45 mAh g −1 and an energy density of 415.48 Wh kg −1 at 0.1 A g −1 , maintaining 80 % capacity after 800 cycles at 0.6 A g −1 . This discovery could lead to the development of innovative two-phase or multiphase manganese-based composites for AZIBs. • Co-Mn 3 O 4 /MnOOH materials were synthesized via a simple magnetic induction method. • The design reduces Jahn-Teller distortion in Mn 3+ during electrochemical reaction. • Device achieves a high energy density (415.48 Wh kg −1 ).