Impact Of Calcination Time On Crystal Structure And Functional Groups In LiFePO4 Battery Cathodes

¹ Lecturer of Mechanical Universitas Kristen Indonesia and Post Doctoral Student of mechanical Engineering Universitas Sumatera Utara.
² Professor Physics Universitas Sumatera Utara, Promotor.
³ Lecturer of Mechanical Engineering Universitas Sumatera Utara, co promotor, Indonesia.
⁴ Student of Mechanical Engineering Universitas Kristen Indonesia.

^* Corresponding author: melcan_sebayang@yahoo.co.id

Abstract

Lithium-ion is the most widely used type of battery because it has high energy density, light weight, and does not experience memory effects. One of the commonly used cathode materials is Lithium Iron Phosphate (LiFePO4). This material can be synthesized from a mixture of LiOH powder, FeS powder, and an H3PO4 solution. The LiOH and FeS powders are first mixed until homogeneous, then dissolved in H3PO4 to allow them to react. The resulting mixture is heated at 60°C using a hotplate and magnetic stirrer for two hours to achieve better homogeneity. Next, solvent evaporation and initial heating are carried out at 200°C for five hours. The material is then calcined at 700°C with varying durations of 1, 3, and 5 hours without using N2 inert gas. XRD testing is conducted to determine the crystallite size, dislocation density, and microstrain of each sample, while FTIR is used to identify the functional groups. The test results show that grain growth does not increase significantly, but higher dislocation density leads to an increase in microstrain. The variation in calcination time from 1 to 5 hours does not cause any changes in the functional groups of LiFePO4.