Preparation of Three Dimensionally Ordered Macroporous LiCoO₂ Cathode for Lithium Batteries

Macroporous LiCoO2 was prepared by a colloidal crystal templating method. Colloidal crystal consisting of monodisperse polystyrene particles was used as the template for the synthesis of macroporous LiCoO2. A Li-Co-O sol was injected into the template, and it was calcined at high temperatures. A porous membrane of LiCoO2 with three dimensionally ordered macroporous (3DOM) structure was obtained. The prepared material had a rock-salt type crystallographic structure with R3m space group. The interconnected macropores with relative uniform size (0.8~0.9 ;m) were observed on entire part of the membrane. The electrochemical properties of the 3DOM LiCoO2 were characterized with galvanostatic charge-discharge measurements in an organic electrolyte containing a lithium salt. The 3DOM LiCoO2 exhibited charge and discharge capacities of 136 and 107 mA h g-1, respectively, at around 3.9 V vs. Li/Li+, indicating that 3DOM LiCoO2 electrode had solid state redox reaction accompanying with Li+ ion insertion and extraction to CoO2 frameworks.