Surfactant-assisted sol–gel route to lithium titanate and its electrochemical properties

The effect of surfactants on the synthesis of lithium titanate (Li₄Ti₅O₁₂-LTO) by sol–gel method is investigated using cationic (cetyl trimethyl ammonium bromide – CTAB), anionic (sodium dodecyl sulphate – SDS) and non ionic (Triton X-100) surfactants. Thermal analysis of the precursor materials directs the heat treatment procedure. The synthesized materials are characterized by X-ray diffraction, surface area analysis and scanning electron microscopy and subsequently evaluated in lithium ion cells using Li metal as counter electrode. The electrochemical performance of the as-prepared LTO is systematically investigated by cyclic voltammetry (CV) and charge/discharge methods. An initial specific capacity of 176 mAhg⁻¹ is obtained for LTO sample synthesized through a CTAB assisted route (LTO-C), whereas the LTO samples synthesized using SDS (LTO-S) and Triton X-100 (LTO-T) exhibits a specific capacity of 142 and 130 mAhg⁻¹, respectively, at C/15 rate. In addition, the CTAB assisted LTO offers good cyclability and high rate capability compared to other two samples. The results show that LTO synthesized through a CTAB assisted method is a promising material for application in rechargeable lithium-ion batteries. - Highlights: • The effect of surfactants on the synthesis of Li₄Ti₅O₁₂ is investigated. • Li₄Ti₅O₁₂ synthesized using cationic surfactant exhibited the best performance. • The first cycle capacity was 176 mAhg⁻¹ at C/15 rate by using cationic surfactant. • Both anionic and non ionic showed inferior performance compared to cationic one.