Template-free reverse micelle process for the synthesis of a rod-like LiFePO4/C composite cathode material for lithium batteries

The synthesis of rod-like LiFePO4/C cathodes using template-free reverse micelle process is reported for high performance lithium batteries. We have demonstrated that the size of the primary particles could be controlled based on sintering temperature and sintering time and size of the large aggregates is adjustable based on the carbon content of the sample. Thermogravimetry and differential thermal analysis have been used to propose a possible mechanism for the formation rod-like LiFePO4/C cathode material. X-ray diffraction, scanning electron microscopy, impedance spectroscopy and charge-discharge measurements have been used to characterize the material. Electrochemical performance of rod-like LiFePO4/C cathode material offers higher initial capacity and excellent rate capability than that obtained by loose porous LiFePO4/C material due to unique rod-like composite material formed by primary nanoparticles. Hence, it can be suggested that that the rod-like nanostructured morphology improves structural stability, lithium ion diffusion and electronic conductivity of the LiFePO4/C composite material. The template-free reverse micelle process for the synthesis of the rod-like LiFePO4/C cathode material opens up a new route to synthesize lithium transition metal oxides with controlled morphologies for applications in high power lithium batteries. (C) 2009 Elsevier B.V. All rights reserved.