Tuning the structural and electrochemical properties of lithium titanate-based anodes via cationic substitution

Lithium titanate is a promising anode material for lithium-ion batteries due to its exceptional structural stability and safety; however, its low electronic conductivity and moderate lithium storage capacity limit its practical application. Here, a dual modification strategy, combining alkali metal substitution and proton exchange, was employed to tailor the structural and electrochemical properties of lithium titanate-based anodes. Lithium sodium titanate (NaLiTi₃O₇, NaLTO) and lithium potassium titanate (K_0.8(Li_0.133Ti_0.867)₂O₄, KLTO) were synthesized via a solid-state reaction, while lithium hydrogen titanate (LiHTi₄O₉·1.5H₂O, HLTO) was obtained via acid-mediated proton exchange. Structural and morphological analyses revealed distinct phase evolution and nanocrystalline architectures, with NaLTO exhibiting the highest crystallinity and surface porosity. Electrochemical results showed that, after 200 cycles at a current density of 50 mAh g−1, NaLTO delivered the highest discharge capacity (∼375 mAh g−1), KLTO exhibited a moderate discharge capacity (∼210 mAh g−1) with good cycling stability, and HLTO showed lower discharge capacity (∼150 mAh g−1) but superior long-term interfacial stability. These findings offer a versatile approach for tuning capacity, rate capability, and stability in titanate-based anodes for next-generation lithium-ion batteries.