Hydro(organic)metallurgy for spent lithium-ion battery recycling

• Main Author: Tan, Christopher Zhi Yong
• Other Authors: Dalton Tay Chor Yong
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Environmental engineering::Waste management; Engineering::Mechanical engineering::Alternative, renewable energy sources
• Online Access: https://hdl.handle.net/10356/166628
• Institution: Nanyang Technological University

Due to the rising inclusivity of electronic devices in one’s daily life, the demand for lithium-ion batteries has been steadily increasing over the years. Thus, the amount of e-waste including lithium-ion batteries follows a similar trend. However, the current recycling processes of spent lithium-ion batteries are not yet truly sustainable as they are either energy and cost intensive, require the use of strong reagents, or produce toxic gases to achieve higher throughput and efficiency. On the other hand, the amount of fruit and vegetable waste has also been on the rise due to the rising population. In a previous study, dried pulverized orange peels were used to leach precious metals from spent lithium-ion battery black mass. Orange peels (OP) act as a source of organic acid and a green reductant as the cellulose can be converted into reducing sugars to aid in the leaching process. This renders the use of harsh reducing agents such as H2O2 redundant, while reducing both electronic and food waste streams concurrently. This project aims to build on the previous study by optimizing the parameters of this novel hydro(organic)metallurgical recycling pathway for lithium-ion batteries. The parameters of fermentation of lactic acid bacteria (LAB) on OP substrate was studied, along with the leaching parameters using the ferment obtained, and finally the parameters of cobalt precipitation using oxalic acid from the leachate obtained. From the project, the parameters for fermentation, amount of concentrated HCl added for leaching, and the parameters for cobalt oxalate precipitation were successfully optimized.