Growth of lithium lanthanum titanate nanosheets and their application in lithium-ion batteries

Abstract

In this work, lithium-doped lanthanum titanate (LLTO) nanosheets have been prepared by a facile hydrothermal approach. It is found that with the incorporation of lithium ions, the morphology of the product transfers from rectangular nanosheets to irregular nanosheets along with a transition from La₂Ti₂O₇ to Li₀.₅La₀.₅TiO₃. The as-prepared LLTO nanosheets are used to enhance electrochemical performance of the LiCo(1/3)Ni(1/3)Mn(1/3)O₂ (CNM) electrode by forming a higher lithium-ion conductive network. The LiCo(1/3)Ni(1/3)Mn(1/3)O₂-Li₀.₅La₀.₅TiO₃ (CNM-LLTO) electrode shows better a lithium diffusion coefficient of 1.5 × 10⁻¹⁵ cm² s⁻¹, resulting from higher lithium-ion conductivity of LLTO and shorter lithium diffusion path, compared with the lithium diffusion coefficient of CNM electrode (5.44 × 10⁻¹⁶ cm² s⁻¹). Superior reversibility and stability are also found in the CNM-LLTO electrode, which retains a capacity at 198 mAh/g after 100 cycles at a rate of 0.1 C. Therefore, it can be confirmed that the existence of LLTO nanosheets can act as bridges to facilitate the lithium-ion diffusion between the active materials and electrolytes.