Manganese Sesquioxide as Cathode Material for Multivalent Zinc Ion Battery with High Capacity and Long Cycle Life

Rechargeable zinc ion battery is considered as one of the most potential energy storage devices for large-scale energy storage system due to its safety, low-cost, high capacity and nontoxicity. However, only a few cathode materials have been studied for rechargeable zinc ion batteries. Here, we firstly report manganese sesquioxide (Mn2O3) with Mn(III) state as cathode material for rechargeable zinc ion battery. The α-Mn2O3 cathode displays a reversible capacity of 148 mAh g−1, which is relatively high among all the reported cathode materials for ZIB. The cathode also exhibits good rate capability and excellent cycling stability with a long cycle life up to 2000 times. The ion storage mechanism of α-Mn2O3 in zinc ion battery was also revealed. The pristine α-Mn2O3 undergoes a reversible phase transition from bixbyite structure to layered-type zinc birnessite during the electrochemical zinc ion insertion and extraction. The results not only benefit for the practical application of rechargeable zinc ion battery, but also broaden the horizons of understanding the electrochemical behavior and mechanism of rechargeable zinc ion batteries.