Comparative life cycle analysis of critical materials recovery from spent Li-ion batteries

The development of new generations of electric vehicles is expected to drive the growth of lithium-ion batteries in the global market. Life Cycle Assessment (LCA) method was utilized in this study to evaluate the environmental impacts of various hydrometallurgical processes in critical materials recovery from lithium-ion battery (LIB) cathode powder. The main objective of this work was to fill the knowledge gap regarding the environmental sustainability of various processes in LIB recycling and to generate a comprehensive comparison of the environmental burdens caused by numerous hydrometallurgical methods. According to this investigation, leaching with acetic acid, formic acid, maleic acid, and DL-malic acid demonstrates lower environmental impacts compared to lactic acid, ascorbic acid, succinic acid, citric acid, trichloroacetic acid, and tartaric acid. Among inorganic acids, nitric acid and hydrochloric acid show higher environmental impacts compared to sulfuric acid. Furthermore, the results of this study indicate that leaching with some organic acids such as citric, succinic, ascorbic, trichloroacetic, and tartaric acids leads to higher negative environmental impacts in most environmental categories compared to inorganic acids like sulfuric and hydrochloric acid. Therefore, not all organic acids utilized in the leaching of critical and strategic materials from cathode powder can enhance environmental sustainability in the recycling process. The results of the solvent extraction study as a downstream process of leaching show that sodium hydroxide, organic reagents, and kerosene have the highest environmental impact among all inputs in this process. Generally, solvent extraction has a greater environmental impact compared to the leaching process.