THE EFFECT OF FLUORINE DOPING AND CALCINATION TEMPERATURE ON Li4Ti5O12/C MATERIAL USING SOLID STATE METHOD

Abstract

Li 4 Ti 5 O 12 /C anode has advantage of stable operating voltage compared to graphite which cannot be used in high rate power conditions and the dimensions of graphite change when first charging. Addition of Fto Li 4 Ti 5 O 12 anode can improve electrochemical performance and influence the morphology of the anode Li 4 Ti 5 O 12 . In this study a synthesis process was carried out and the addition of variations of F (0.1; 0.15; 0.2 moles) into Li 4 Ti 5 O 12 anode using the solid state reaction method. Then the calcination process was carried out with temperature variations of 700, 750 and 800°C. The reaction product is coated with carbon sourced from acetylene and argon gas. The XRD results show the highest peak at 2θ around 17-20°. The addition of F has been successfully carried out on LTO material. Ion F has been incorporated into the LTO crystal structure by substituting O ions without causing changes in the crystal structure characteristics. The presence of element F causes the XRD peak to change in a lower direction so that it becomes more crystalline, with the smaller lattice parameters and unit cells. SEM testing result was carried out to determine the morphology of anode Li 4 Ti 5 O 12 /C material. At calcination temperatures of 700 and 750°C the Li 4 Ti 5 O 12 /C particles had irregular sphere shaped with nanometer size and homogeneous distribution. However, at a calcination temperature of 800°C agglomeration occurred, so that the particles adhere to each other and enlarge. This condition affects the electrochemical performance of the sample.