Effect of Solvent on the Electrochemical Performance and Morphology of Solution Combustion-Synthesized LiFePO۴ Cathode

Among several cathodic materials, LiFePO۴, with a high specific capacity, thermal and chemical stability, and long-term cyclability is a good choice for lithium-ion battery cathodes. However, drawbacks such as low ionic and electronic conductivity limit the applications of this cathodic material. Coming up with solutions for these problems is a must. To overcome this challenge several approaches such as doping, reducing particle size, coating, controlling the morphology, and compositing have been employed. In this research effect of solvent on electrochemical performance and morphology of LiFePO۴ that is synthesized with the solution combustion method was the main aim. Water, ethanol, and a mixture of water-۵۰%ethanol were used as solvents in preparing the samples. Solution combustion synthesis was performed utilizing cetyltrimethylammonium bromide (CTAB) as combustion fuel. The characteristics of prepared samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and various electrochemical performance testing methods. The sample that was prepared with water-۵۰%ethanol solvent exhibited better electrochemical performance (discharge specific capacities of ۱۲۹, ۱۲۵, ۱۱۵, ۱۰۵, ۹۴, ۷۶, ۵۸, and ۳۶ mAh/g respectively at ۰.۱C, ۰.۲C, ۰.۵C, ۱C, ۲C, ۵C, ۱۰C, and ۲۰C) and more homogenous morphology compared to the other two samples.

کلیدواژه ها:

Lithium-ion battery ، LiFePO۴ ، Electrochemical performance ، Solution combustion synthesis