Improving the electrochemical performance of the Li₄Ti₅O₁₂ electrode in a rechargeable magnesium battery by lithium-magnesium co-intercalation

Rechargeable magnesium batteries have attracted recent research attention because of abundant raw materials and their relatively low-price and high-safety characteristics. However, the sluggish kinetics of the intercalated Mg²⁺ ions in the electrode materials originates from the high polarizing ability of the Mg²⁺ ion and hinders its electrochemical properties. Here we report a facile approach to improve the electrochemical energy storage capability of the Li₄Ti₅O₁₂ electrode in a Mg battery system by the synergy between Mg²⁺ and Li⁺ ions. By tuning the hybrid electrolyte of Mg²⁺ and Li⁺ ions, both the reversible capacity and the kinetic properties of large Li₄Ti₅O₁₂ nanoparticles attain remarkable improvement. Synergy between Mg²⁺ and Li⁺ ions: By controlling the collaborative electrochemistry of magnesium and lithium cations, Li₄Ti₅O₁₂ electrodes (LTO; see picture) close to sub-micron size gain extraordinary electrochemical energy storage capability. The electrodes show improved kinetics in rechargeable magnesium batteries.