Surfactant-assisted microemulsion approach of chrysanthemum-like Co3O4 microspheres and their application in lithium-ion battery

A simple approach to synthesize Co3O4 in mass production by using surfactant (CTAB) and cosurfactants (C5H12O and C8H12O) via the microemulsion treatment has been developed. By changing the reaction times, the prepared Co3O4 was readily regulated in its morphologies varying from the chrysanthemum-like microspheres in bud to in full bloom. The sample reacted for 6 h maintains 565.5 mAh.g(-1) after 30 cycles at a current density of 60 mA.g(-1), and 495.1 mAh.g(-1) after 40 cycles at a current density of 80 mA.g(-1). Although the cycling performance at a current density of 50 mA.g(-1) started to fall off in the initial 20 cycles, the capacities were still comparable to the theoretical capacity of graphite (372 mAh.g(-1)) after more than 100 cycles. The above 95% capacity retention after 20 cycles is believed to benefit from unique structural features, particularly clusters of nanofibers. The chrysanthemum-like nanostructures with larger BET specific surface area created an easier and shorter diffusion pathway for ionic and electronic diffusion, which resulted in good power performance. (c) 2012 Elsevier B.V. All rights reserved.