Preparation and characterization of three dimensionally ordered macroporous Li4Ti5O12 anode for lithium batteries

Three dimensionally ordered macroporous (3DOM) Li4Ti5O12 membrane (80 μm thick) was prepared by a colloidal crystal templating process. Colloidal crystal consisting of monodisperse polystyrene particles (1 μm diameter) was used as the template for the preparation of macroporous Li4Ti5O12. A precursor sol consisting of titanium isopropoxide and lithium acetate was impregnated into the void space of template, and it was calcined at various temperatures. A macroporous membrane of Li4Ti5O12 with inverse-opal structure was successfully prepared at 800 °C. The interconnected pores with uniform size (0.8 μm) were clearly observed on the entire part of membrane. The electrochemical properties of the three dimensionally ordered Li4Ti5O12 were characterized with cyclic voltammetry and galvanostatic charge and discharge in an organic electrolyte containing a lithium salt. The 3DOM Li4Ti5O12 exhibited a discharge capacity of 160 mA h g−1 at the electrode potential of 1.55 V versus Li/Li+ due to the solid state redox of Ti3+/4+ accompanying with Li+ ion insertion and extraction. The discharge capacity was close to the theoretical capacity (167 mA h g−1), which suggested that the Li+ ion insertion and extraction took place at the entire part of 3DOM Li4Ti5O12 membrane. The 3DOM Li4Ti5O12 electrode showed good cycle stability.