The Influence of Platinum Doping on the Structure, Morphology and Electrochemical Properties of LiFePO4/C Cathode Material

In this work, a dual approach of metal doping and carbon coating was employed to improve the poor ion diffusion rate and low electrical conductivity of LiFePO₄, respectively. LiFePO₄ and LiFe_0.96Pt_0.04PO₄ materials were synthesized using a sol-gel method followed by carbon coating with sucrose. The effect of platinum doping on the physical-chemical properties and the electrochemical performance of LiFePO₄/C material were investigated by XRD, XPS, SEM, carbon analyzer, charge/discharge testing, cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical results showed that the specific discharge capacities of the material significantly increased by platinum doping. This improvement will be discussed considering the expansion of the lattice parameter, reducing the particles size with uniform distribution and pillar effect of platinum element for stabilizing the crystal structure.