Researchers at University of Toronto have found a new way to recover lithium, cobalt, nickel and manganese from spent batteries. They have discovered an alternative method for recycling lithium-ion batteries with CO2, after they elevate it to supercritical level. And they claim this is cheaper, and safer than prevailing commercial methods.
Commercial Ways for Recycling Lithium-Ion Batteries
Eurek Alert says conventional processes employ high-energy pyrometallurgy, or hydrometallurgy extraction. The former relies on extremely high temperature producing greenhouse gas emissions. While the latter uses acids and reducing agents for extraction, leaving a residue of waste water.
However, the team at University of Toronto Engineering say they have found a better, new way for recycling lithium-ion batteries than that. They are using supercritical fluid extraction to recover metals from end-of-life batteries instead. This process separates out components with an extracting solvent at a temperature and pressure above carbon dioxide’s critical point.
How Does This New Method Work in Practice?
The team uses carbon dioxide as a solvent that they first bring to supercritical phase. This involves increasing the temperature above 31° celsius, and the pressure up to 7 megapascals. At this point their solvent adopts the properties of both a liquid and a gas. It then separates one battery component from another according to Eurek Alert.
Advantages of Recycling Lithium-Ion Batteries This Way
The University of Toronto Engineering team reports their method comes within 90% efficiency compared to conventional leeching. Although it uses less energy and chemicals, while generating “significantly less secondary waste”. Moreover, most energy “is due to the compression of the carbon dioxide”.
“The advantage of our method is that we are using carbon dioxide from the air as the solvent. Instead of highly hazardous acids or bases,” explains Professor Gisele Azimi standing next to PhD candidate Jiakai (Kevin) Zhang in our photo. “Carbon dioxide is abundant, cheap and inert, and it’s also easy to handle, vent and recycle.”
Breaking News
LiFePO4 Batteries Are Set to Take a Lead
Power from the Soil Beneath Our Feet
Preview Image: Prof Azimi and Student Zhang
