SYNTHESIS OF DEPO4 FOR PRECUSOR OF LIFEPO4 BATTERY CATHODE FROMARTIFICIAL SOLUTION SIMULATING FERRONICKEL (FENI) PREGNANT LEACHSOLUTION

• Main Author: Maulana Pohan, Aldi
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/76846
• Institution: Institut Teknologi Bandung

The growth of the electric vehicle industry has driven the demand for raw materials for batteries. One type of battery for electric vehicles that is widely used is the lithium-ion battery with a LiFePO4 (lithium-iron phosphate, LFP) cathode. With the main content of iron and nickel, ferronickel (FeNi) can be an alternative for use as a raw material for iron phosphate (FePO4) and nickel sulfate (NiSO4.6H2O), both of which are raw materials for cathode lithium-ion batteries. In previous research, direct leaching of FeNi which has been carried out by roasting in hydrochloric acid solution has been studied. In this research, the FePO4 synthesis process was carried out from an artificial solution which simulated the leaching of FeNi (which had been roasted) in a hydrochloric acid solution. The experiment began with the preparation of an artificial solution that simulated a solution of FeNi leaching that had gone through a roasting process by dissolving pro-analysis reagents namely FeCl3.6H2O, NiCl2.6H2O, CoCl2.6H2O, CrCl3.6H2O, and MnCl2.4H2O in distilled water. Furthermore, the artificial solution was oxidized by adding hydrogen peroxide for 1 hour to ensure that all dissolved Fe was in the form of Fe3+ before the precipitation experiment started. After the oxidation was completed, the precipitation experiment was started by adding NH4H2PO4 as a phosphate source for 5 minutes, followed by experiments with a variation of the precipitation variables which included pH, temperature, P/Fe mole ratio and the addition of FePO4 seed. Finally, AAS analysis was carried out on the filtrate and solution obtained from the digestion of the precipitate, as well as SEM and XRD analysis on the precipitate obtained to determine the percentage of metal precipitation and the optimum conditions for producing the best FePO4 product. The results showed that increasing the pH and adding seed increased the % Fe precipitation and % co-precipitation of other metals (Ni, Co, Cr, and Mn). Increasing temperature increases the % precipitation of Fe but has no consistent effect on the precipitation of other metals, while increasing the P/Fe mole ratio to 1 increases the percentage of Fe precipitation. The best conditions were obtained at pH 1.8, temperature 70 oC, mole ratio P/Fe 1, and without the addition of seed with Fe precipitation of 94.71%, and %co-precipitation of Ni, Co, Cr, and Mn respectively of 2.06%, 3.50%, 9.91% and 21.53%. Based on the results of AAS and XRD the FePO4 obtained was in accordance with commercial FePO4 with an iron content of 30.95%.