Hydrometallurgical Recovery of Lithium and Cobalt from Spent Lithium-Ion Batteries

Obetta, Emmanuel Chinonso (2019-07-12)

Thesis

The demand for lithium-ion batteries is high because of their high energy and power density, which most time is influenced by the lithium-ion cathode chemistry. However, the need for expensive and scarce metals, such as lithium and cobalt, in the cathode of these batteries will limit the supply of these batteries in the future. Thus, the need for a better way to retrieve the valuable metals in spent lithium-ion batteries. This study compares the morphology and chemical content of cathode active materials detached from the current collector (Aluminium foil) using DMSO, NMP and scratching. In addition, we investigated the viability of extracting cobalt and lithium by leaching using citric acid and precipitating using potassium hydroxide and sodium carbonate for cobalt and lithium, respectively. The results show that the morphologies of the cathode materials detached using the aforementioned methods are the same. Furthermore, the final result showed that cobalt and lithium can be recovered by leaching using citric acid (Leaching condition: solid/Liquid ratio (S/L) = 8 g/200 mL, 90 °C. 1 vol% H 2 O 2 ) and precipitation [Precipitation condition: 4 M NaOH, pH = 12 (for cobalt)].