Enhancement of electrochemical properties of platinum doped LiFePO4/C cathode material synthesized using hydrothermal method

• LiFePO4 and LiFe0.96Pt0.04PO4 cathode materials were prepared by hydrothermal method.
• The platinum doping increase the lithium ion diffusion coefficient of LiFePO4.
• Smaller particle sizes with uniform distribution is obtained for LiFe0.96Pt0.04PO4.
• The platinum doping sample exhibits better electrochemical properties and cycling.

The Pt-doped LiFePO4/C cathode material was synthesized for the first time. LiFePO4 and LiFe0.96Pt0.04PO4 composites were synthesized using a hydrothermal method. The physical and chemical properties of samples were characterized by XRD, XPS, SEM and BET. For electrochemical property investigation, the samples were mixed with sucrose as carbon source, and calcined at 700 °C for 5 h. The XRD results showed that the platinum has been successfully doped into LiFePO4 bulk structure. The XPS results indicated that platinum doping does not change the chemical state of Fe (II). The SEM and BET results showed that platinum doping reduces the size of the particles. The electrochemical characterization of the electrodes using discharge capacity, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) showed that the Li-ion cell based on LiFe0.96Pt0.04PO4/C electrode exhibited better charge/discharge performance than that of LiFePO4/C sample. The LiFe0.96Pt0.04PO4/C based cell delivered the specific capacity of 168, 162, 135, 120 and 102 mAh g− 1 at 0.1C, 0.2C, 1C, 5C and 10C, respectively, in comparison with 117, 104, 83, 63 and 47 mAh g− 1 for the LiFePO4/C cell.