Inducing Mn defects within MnTiO cathode for aqueous zinc-ion batteries.

Layered manganese-based cathode materials are considered as one of the promising cathodes benefit from inherent low manufacturing cost, non-toxic and high safety in aqueous zinc-ion batteries (AZIBs). However, the sluggish reaction kinetics within layered cathodes is inevitable due to the poor electrical/ionic conductivity. Herein, MnTiO is reported as a new cathode material for AZIBs and in-situ induced Mn-defect within MnTiO during the first charging is desirable to improve the reaction kinetics to a great extent. Additionally, DFT calculations further demonstrate that MnTiO with manganese defects exhibits a uniform charge distribution at the defect sites, enhancing the attraction towards H and Zn ions. Furthermore, it performs good cycling stability which can obtain 115 mA h g even at 400 mA g after 450 cycles and the discharge capacity reaches up to 233.8 mAh/g at 100 mA g when Mn-defect MnTiO was employed as the cathode. This research could provide a new method for the development and mechanism research of cathode materials for AZIBs.