Meng Shi joined the Idaho National Laboratory in January 2021 as a postdoctoral researcher, working in Project 3.1.11 Lithium, Cobalt & Platinum Group Metals Recovery from Lithium-ion Batteries. She earned her Ph.D. degree in Chemical Engineering, particularly in the electrochemical studies. Her Ph.D. research worked with both high and low temperature molten salts for metal oxide reductions and metal plating. In the Project 3.1.11, she worked with mentors on the critical metal recovery from the spent lithium ion battery (LIB) materials. Critical metals in the spent LIB are first dissolved in a leachate solution through an electrochemical (EC) leach process. Metals of interests include lithium, manganese, nickel and cobalt. Then Ni and Co are separated from the leachate through either an ion-exchange or a solvent-extraction method. The separated Ni and Co are then recovered as high purity or even battery-grade NiSO4 and CoSO4.
"With the left Li/Mn-rich leachate, we introduce an electrodialysis step to separate Li and Mn, and recover battery-grade Li2CO3, as well as MnO2 and MnCO3 as side products," she said. "Our processes have low energy and chemical costs, and the carbon-negative operation in Li2CO3 recovery also reduce the carbon footprint in the entire operation."