Insights of cobalt doping on carbon-coated LiFePO4 olivine nanoparticles prepared by citric acid combustion route as cathodes for lithium batteries

Here, we report the preparation of carbon-coated cobalt-doped olivine nanoparticles (LiFePO4/C) by the citrate gel precursor combustion method. The major contribution of this work is to reveal insights and side effects of cobalt doping, not only in the structure, microstructure, and electrochemical performance of olivine nanoparticles, but also in the consequences on the carbon coating characteristics. Our structural and microstructural studies by means of several instrumentation techniques revealed that the presence of low amounts of cobalt during the synthesis leads to the apparent formation of more porous channels in the carbon coating. In consequence, the electrochemical characterization showed an enhancement in the capacity and diffusion constants for cobalt-doped LiFePO4/C samples in comparison with cobalt-undoped samples.