Advances in recycling LiFePO4 from spent lithium batteries: a critical review

LiFePO4 batteries have become one of the most promising batteries due to their excellent electrochemical performances, long life cycle, safety, and abundant mineral resources. As a result, the demand and scraped LiFePO4 batteries increased dramatically in recent years. The recycling of waste LiFePO4 batteries has raised great attention with the consideration of environmental issues and resources conservation. To date, there are massive literatures on the recycling of LiFePO4 batteries aiming at providing an effective, economic and environmentally sustainable approach. Consequently, this review sorts out and analyzes the current advances in recycling LiFePO4 from spent lithium batteries with the purpose of promoting the improvement of their recycling. Based on the damage degree of LiFePO4 materials, direction regeneration and hydrometallurgical leaching are the main recycling processes. The direction regeneration of LiFePO4 routes including high temperature solid regeneration, hydro/solvent thermal regeneration and electrochemical lithiation are discussed in detail. Inorganic or organic acid leaching, mechanically activated leaching and other leaching methods are reviewed as well. Finally, by comparing the various recycling technologies, the challenges are outlines and future directions for promoting the recycling effectiveness are proposed.