Synthesis and electrochemical characterization of 2D nanostructured Li4Ti5O12 with lithium electrode functionality

Two-dimensional (2D) Li4Ti5O12 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 Li4Ti5O12 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 Li4Ti5O12. The 2D nanostructured Li4Ti5O12 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.