Improving High‐Rate and Long‐Life Cycling of Li₄Ti₅O₁₂ Anode by Dual Doping of Cd²⁺ and Ge⁴⁺

Abstract A kinetically favored Cd²⁺ and Ge⁴⁺ dual‐doped lithium titanate (Li₄Ti₅O₁₂) anode material is designed for lithium‐ion batteries (LIBs). Rietveld refinement reveals that introducing a 0.05 wt.% of Cd²⁺ at Li(8a) and Ge⁴⁺ at Ti(16d) sites brings no structural change in the spinel Li₄Ti₅O₁₂. Scanning transmission electron microscopy (STEM) identifies Cd²⁺ and Ge⁴⁺ are homogenously doped in the Li₄Ti₅O₁₂ lattice. High‐resolution powder diffraction (HRPD) confirmed that Cd²⁺ and Ge⁴⁺ doping in Li₄Ti₅O₁₂ brings expansion in the lattice, field emission scanning electron microscopy (FE‐SEM) shows the reduction in the particle size due to of Cd and Ge in the LTO lattice, and X‐ray photoluminescence spectroscopy (XPS) confirms the partial reduction of Ti⁴⁺ to Ti³⁺ ions on the surface of 0.05‐Cd‐Ge‐LTO electrodes to the pristine LTO. Furthermore, the 0.05‐Cd‐Ge‐Li₄Ti₅O₁₂ electrode exhibits a superior rate performance and delivers a discharge capacity of ≈169.1 mAhg⁻¹ at 0.1 current rates. It is worth mentioning that, the 0.05‐Cd‐Ge‐Li₄Ti₅O₁₂ electrode brings outstanding cycling stability in Li⁺ half‐cell, having a capacity retention of 98.79% after 300 cycles at 2C. This proves that dual‐doping of Cd²⁺ at Li(8a) and Ge⁴⁺ at Ti(16d) sites in the Li₄Ti₅O₁₂ lattice is an effective approach to obtain superior electrochemical performance as anode material in LIBs.