Extracting Lithium from Low Concentration Solutions for Direct Battery Cathode Production

Abstract

Lithium (Li) is one of the critical industrial materials and an indispensable component in manufacturing Li-ion/Li batteries. However, Li resource is very limited and geographically uneven in earth’s crust and its mining is not sustainable due to the low efficiency and complicated separation and refining processes. Hence, direct Li recovery (from brines, seawater or used cells) and utilization are desired. Here, we report a novel technology to recover Li from low concentration solutions into a form of Li resource, which can be directly used for commercial battery materials production by fully eliminating the costly Li separation steps. By using both Li-ion selective membrane and low-cost Li host structural material, highly selective Li extraction was realized. Li-ion cathodes (e.g., spinel LiMn2O 4 and layered LiNix MnyCozO2) were synthesized with the extracted Li and have high phase purities and economic superiorities (e.g., $12.8 kg-1 for LiMn2O4) over other Li extraction methods and even commercial cathodes ($15 kg-1 for LiMn2O4). This contribution provides a potential technical pathway to overcome the challenges of both Li supply and battery cost for future electrification and decarbonization of socioeconomic system.