Comparison of Hydrometallurgical and Hybrid Recycling Processes for Lithium-ion Battery: An Environmental and Cost Analysis

Abstract There is a strong emphasis on shifting to Electric Vehicles (EVs) throughout the globe for reducing the impact on global warming. Lithium-ion Batteries (LIBs) are predominantly used in EVs and these can be a significant threat to the environment if not disposed safely. Two routes namely pyrometallurgical and hydrometallurgical processes have been proposed in the literature for recycling LIBs. In this paper, we focus on quantifying the environmental impact of hydrometallurgy and hybrid (pyrometallurgy followed by hydrometallurgy) recycling processes and determine the option which has a lower impact on the environment. Life Cycle Assessment (LCA) is used for the environmental impact assessment of LIB recycling. The analysis is performed assuming ideal conditions for the hydrometallurgical and hybrid process in the inventory analysis. The reason being it was possible to determine the reaction yields only by theoretical calculations and not by field or experimental study. We have provided the lower bounds of impact by assuming a 100% conversion rate for the calculation of reaction yields in inventory analysis. Hence, this paper serves as a precursor or feasibility study for the policy-making step before setting up the battery recycling plants. The main contribution of this research is stepwise methodology development for LCA of LIB recycling and theoretical estimation of the reaction yields for inventory analysis. It was found that the cathode, anode, and foil of the LIB contribute most to the impact compared to the rest of the inputs. The impact due to separator, cell case, cables, leaching agent, slag-forming agent and reducing agent were minimum. The results show that the environmental impact of the hybrid process is found to be slightly better than the hydrometallurgy process across all environmental indicators. Further, a simple cost analysis was performed, and it also supports the hybrid process as a better option due to lesser variable costs.