Facile synthesis of Co3O4 nanocrystals with superior lithium storage properties from bis (8-hydroxyquinoline) cobalt complex as anode materials for lithium-ion batteries

A simple and facile approach to synthesis Co3O4 nanocrystals by a two-step pyrolysis process of bis (8-hydroxyquinoline) cobalt complex under Ar and air atmospheres successively. The structures and physical properties of the complex, Co@C intermediate and the Co3O4 nanocrystals are characterized by the following techniques: FTIR, XRD, TGA-DTG, Raman, FESEM, HRTEM, N2 adsorption/desorption measurement and XPS. As anode materials in lithium ion batteries, the Co3O4 nanocrystals exhibit high charge/discharge specific capacity, excellent rate performance and remarkable cycle stability. The superior electrochemical properties of the Co3O4 nanocrystals could be attributed to the nanoscaled particle size, high crystallinity and high specific surface area, which is helpful to increase the number of active sites, shorten the diffusion path of lithium ions and electrons, alleviate the volume expansion effect as well as improve the dynamic characteristics during cycling.