SYNTHESIS OF NaFePO4 WITH NICKEL DOPING FOR SODIUM ION BATTERY CATHODE

• Main Author: Ilham Bayquni, Muhammad
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/42834
• Institution: Institut Teknologi Bandung

The abundance of sodium resources is a potency that strongly supports the existence of research on sodium ion batteries in Indonesia as an alternative to lithium ion batteries. NaFePO4 is chosen as an analogous material of the LiFePO4 cathode. In this study, NaFePO4 is synthesized through the sol gel method with NaCl precursors, then calcined in the atmosphere of the inert N2 gas at 600°C with a holding time of 1 hour. Based on the XRD test, NaFePO4 with the maricite phase is successfully obtained. Modification of NaFePO4 structure is carried out by nickel doping as an isovalent cation of iron, so it is expected to have an impact on increasing the performance of sodium battery. Based on the XRD test, the main peaks of the maricite phase are recognized at 2? ? 32.8°, 33.1°, and 34.8°, according to the miller index (220), (211), and (031), and the size of the crystallite ranges between 45 nm and 136 nm. Meanwhile, there is no observed change in NaFePO4 peaks with nickel doping in the XRD test. This shows that nickel doping does not cause major structural changes of the maricite phase of NaFePO4. The composition of NaFePO4 cathode with nickel doping variation of 1% and 5% examined with the XRF test, nickel in the NaFePO4 pellet sample is observed at 0.56% and 4.33% respectively. The presence of nickel in the NaFePO4 structure is examined further by HRTEM test and also the EDS test. Previously, the SEM test is carried out to examine the size of NaFePO4 particles as well as the morphology which is found to form elongated squares. It is known that nickel doping successfully penetrates into the NaFePO4 structure, approved in the crystal field (031) and (012) through analysis of SAED. Implications of nickel doping on the NaFePO4 structure is examined with galvanostatic charge/discharge test with a current of 0.8327 mAh and a voltage between 2 - 4 V. It is found that NaFePO4 cathode with nickel doping exhibits higher capacity of 15.57% and more stable charge profile.