Synthesis and electrochemical properties of sticktight-like and nanosheet Co3O4 particles

Abstract

Sticktight-like particles and nanosheets of basic cobaltous carbonates of different morphologies are synthesized through a hydrothermal process. Their structures and formulas are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray absorption fine structure and thermogravimetry. After being calcined at 400 °C and 500 °C, these basic cobaltous carbonates change into Co3O4 powders and are used as electrode materials of lithium ion batteries. The electrochemical test shows that Co3O4 powders with different morphologies are of different electrochemical performance. Owing to the better mechanical strength and better continuity for electron conduction compared with the sticktight-like Co3O4 samples, the 400 °C- and 500 °C-calcined nanosheet Co3O4 samples show better cycling performance and rate performance. They retain a capacity of over 700 mAh g−1 at 10 C current density. The 400 °C-calcined nanosheet Co3O4 sample exhibits a low initial capacity loss of 18.8%. An even less initial capacity loss of about 15.6% is measured for the sticktight-like Co3O4 sample.