IN-SITU PYROLYSIS OF END-OF-LIFE BATTERY: LITHIUM-ION NICKEL-COBALT-ALUMINIUM OXIDE

• Main Author: Santoso, Teresia
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/65690
• Institution: Institut Teknologi Bandung

The increasing application of lithium-ion batteries for energy storage systems leads in the increase in the number of end-of-life batteries in the future. Through the lithium-ion battery recycling process, it is possible to utilize the precious metals contained in the end-of-life lithium-ion batteries, thereby minimizing environmental damage that may occur due to improper handling of the end-of-life lithium-ion batteries. In this study, in-situ pyrolysis of nickel-cobalt-aluminum oxide lithium-ion battery as a pre-treatment method of lithium-ion battery recycling has been studied. The in-situ pyrolysis approach was chosen to increase recycling efficiency, reduce the risk of losing valuable materials, and elliminate the agglomeration stage of the battery active materials. Experimental procedures that have been carried out include battery discharging, insitu pyrolysis, and characterization of theyrolysis results. Various salt solutions have been used in the discharging step, including 10% NaCl solution, 10% Na2CO3 solution, and sea water. In the in-situ pyrolysis step, the holding temperature was varied from 500°C to 900°C with the holding time being 30 minutes and 120 minutes. The samples used in the preliminary experiments was batteries with LiMnxOy (LMO) cathode while the samples used in the main experiments were batteries with Li(Ni,Co,Al)O2 (NCA) cathode brand Panasonic NCR 18650B. The interaction between the cathode and anode in the battery cells at various temperatures and holding times was analyzed using Scanning Electron Microscope- Energy Dispersive Spectrometry (SEM-EDS), while information on the phase formed in the pyrolyzed active material powders was obtained using X-Ray Diffraction (XRD) analysis method. Based on the measurement of voltage during the battery discharging, seawater and 10% NaCl solution provided the same final voltage in the range of 0.8 volts. To reach the lowest stable voltage, seawater required more than 6 hours discharging, while 10% NaCl solution achieved the same voltage after 1.6 hours. Starting from a temperature of 500°C for a holding time of 120 minutes, a reduction reaction of the cathode material has occurred resulting the metallic phases of cobalt and nickel metals. At a temperature of 500°C - 800°C, the reduction extent of the cathode material increased as the holding time increases. The reduction extent of the cathode material also increased with increasing pyrolysis temperature both via carbothermic and aluminothermic reduction mechanisms. The most effective in-situ pyrolysis condition for the cathode material reduction process is at 700°C with a holding time of 120 minutes because it produces Co and Ni metal phases with minimum loss of Li metal from side reaction of LiAlO2 phase formation.