Electrochemical Li Recovery from Spent LiFePO 4 -Based Li-Ion Batteries

The increase in electric vehicles (EVs) powered by lithium-ion batteries (LIBs) will generate a massive number of spent LIBs in the future. LiFePO4 has recently become the most desired cathode for LIBs in EVs because it is remarkably cheaper and safer than other cathodes. Recovering lithium from spent LiFePO4 batteries using conventional methods, however, may not be economically viable because there are no valuable metals to recover in LiFePO4 other than lithium. This study reports the invention of an electrochemical system, composed of a Li+-extraction cell and a Li+-recovery cell, which can recycle Li+ from spent LiFePO4-LIBs as Li3PO4, Li2CO3, or LiOH using simple and cost-effective procedures. While recovering Li+, these cells also regenerate the acid consumed for Li+ leaching, minimizing the chemicals needed and the waste generated, enabling sustainable and environmentally benign Li+ recycling. The choice of electrodes, operation principles, performance, and variation of the Li+-extraction/recovery cells are reported.