Improvements in the Electrochemical Performance of Sodium Manganese Oxides by Ti Doping for Aqueous Mg-Ion Batteries

Abstract

In recent times, the research on cathode materials for aqueous rechargeable magnesium ion battery has gained significant attention. The focus is on enhancing high-rate performance and cycle stability, which has become the primary research goal. Manganese oxide and its derived Na−Mn−O system have been considered as one of the most promising electrode materials due to its low cost, non-toxicity and stable spatial structure. This work uses hydrothermal method to prepare titanium gradient doped nano sodium manganese oxides, and uses freeze-drying technology to prepare magnesium ion battery cathode materials with high tap density. At the initial current density of 50 mA g⁻¹, the NMTO-5 material exhibits a high reversible capacity of 231.0 mAh g⁻¹, even at a current density of 1000 mA g⁻¹, there is still 122.1 mAh g⁻¹. It is worth noting that after 180 cycles of charging and discharging at a gradually increasing current density such as 50–1000 mA g⁻¹, it can still return to the original level after returning to 50 mA g⁻¹. Excellent electrochemical performance and capacity stability show that NMTO-5 material is a promising electrode material.