Understanding of the Li-insertion process in a phosphate based electrode material for lithium ion batteries

Being considered as a high Li-ion mobility material, Nasicon structured Li1.5Fe0.5Ti1.5(PO4)(3) phosphate material was synthesized via sol-gel route and electrochemically tested as electrode material for lithium-ion batteries. The material was tested in half-lithium electrochemical cells, within two voltage windows, 1.5-3.0 V and 0.5-3.0 V, and delivered first discharge capacities of 129 mAh/g and 567 mAh/g, respectively. Raman spectroscopy was used to confirm the material's structure before and during cycling. In addition, a comparative study of the electrochemical performance by the use of two different binders (PVDF and CMC), was conducted and showed a significant change in the electrochemical performance due to the change of the binder. Electrochemical impedance spectroscopy was used to evidence the electrodes' interface changes during cycling.