Synthesis and electrochemical characterization of 2D nanostructured Li ₄Ti ₅O ₁₂ with lithium electrode functionality

Two-dimensional (2D) Li ₄Ti ₅O ₁₂ nanosheets with cubic spinel structure are synthesized via a lithiation process of exfoliated titanate 2D nanosheets and the subsequent heat-treatment at elevated temperatures. According to powder X-ray diffraction and field emission-scanning electron microscopy analysis, the obtained lithium titanium oxides show well-developed Bragg reflections of cubic spinel-structured Li ₄Ti ₅O ₁₂ phase and highly anisotropic 2D plate-like morphology. Ti K-edge X-ray absorption near-edge structure analysis reveals the stabilization of tetravalent titanium ions in the cubic spinel lattice of Li ₄Ti ₅O ₁₂. The 2D nanostructured Li ₄Ti ₅O ₁₂ materials display the electrochemical functionality as negative electrode for lithium secondary batteries. The most promising electrode performance is achieved by the heat-treatment of the lithiated titanate at 600 °C, highlighting the importance of heating temperature in optimizing the electrochemical property of the resulting materials.