PENINGKATAN KONDUKTIVITAS LISTRIK LiFePO4 SEBAGAI MATERIAL KATODA BATERAI SEKUNDER LITIUM DENGAN PELAPISAN KARBON DAN DOPING TiO2

• Main Authors: , DESTY ANGGITA TUNGGADEWI, , Dr. Kuwat Triyana
• Format: Theses and Dissertations NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2012
• Subjects: ETD
• Online Access: https://repository.ugm.ac.id/100635/; http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=57150
• Institution: Universitas Gadjah Mada

Improving electrical conductivity of LiFePO4 as cathode material for secondary lithium battery had been reached by employing carbon coating and TiO2 doping. Synthesis and the coating process are conducted in two stages of heating by the sol-gel method. The starting materials for forming of LiFePO4 are the powder of Li2CO3, NH4H2PO4 and FeC2O4.H2O. Citric Acid and Polyetyleneglycol are used as the agent for creating porosity in active cathode material LiFePO4. Beside that, Citric Acid is also used as the carbon source for LiFe1-xTixPO4/C. Meanwhile Titanium dioxide is used as the doping element. Applied temperature of the synthesis prosess and amount of doping element are varied, respectively 700, 800 and 900°C for 12 hours and 0, 2 and 4 % wt TiO2. Temperature and time of carbon coating process is fixed at 700°C for 10 hour, amount of carbon coating is 4 wt %. This is done to observe their effects on the electrical conductivity of the cathode material. The phase composition of the synthesized active material is analyzed by XRD. This analysis indicates that the expected phase was formed as LiFePO4. Ti ions were sufficiently doped in LiFePO4 and did not alter its crystal structure. The morphology and distribution of carbon in the material LiFe1- xTixPO4/C were analyzed by SEM/EDX. Increasing the synthesis temperature will increase the particle size and create less porosity. It was decreased the electrical conductivity of LiFe1-xTixPO4/C. Electrical conductivity of LiFe1-xTixPO4/C was tested by the Electrochemichal Impedance Spectroscopy (EIS). This test showed that the electrical conductivity of LiFe1-xTixPO4/C increased by the decreasing of LiFePO4 sintering temperature and the decreasing of the dopant quantity. Carbon coating and doping TiO2 have been successfully improving electrical conductivity of LiFe1-xTixPO4/C. The highest conductivity of LiFe1-xTixPO4/C is obtained by heating at 700ºC and 2% wt TiO2, i.e. in the order of 10-2S/cm.