Fig. 3: Electrochemical performance with respect to reversible capacity, discharge rate, and long-term cyclability.

a Potential profiles of Mg_0.27Li_0.09Ti_0.11Mo_0.22O at room temperature with a current density of 10 mA g⁻¹ in the potential window of 4.1 V for charging and 1.8 V vs. Li RE for discharging. The inset shows the rate capability for discharging to 1.7 V vs. Li RE, in which the cell was charged to 4.2 V vs. Li RE at a common current density of 10 mA g⁻¹ before each discharging test. b Cell voltage profiles obtained from E_WE − E_CE in (a), where the counter electrode was pure Mg metal. The vertical axis was, therefore, converted from the electrode potential into net cell voltage. c Capacity retention corresponding to (a). Filled and open circles indicate the discharging and charging capacity, respectively. Green diamonds represent the Coulombic efficiency.