Chapter 13 - Separating battery nano/microelectrode active materials with the physical method

Lithium-ion batteries (LIBs) dominate the rechargeable batteries industry because of their many advantages, including high energy and power density and a relatively long lifespan. Despite these advantages, the disposal of spent LIBs in landfills harms the environment, which must be addressed by recycling. The available recycling methods for spent LIBs, such as pyrometallurgy and hydrometallurgy, focus only on collecting the valuable elements from spent LIBs. The direct physical recycling method may be more economical than the other two methods if mixed cathode and anode active materials are separated, directly regenerated, and then used to make new LIBs. The first obstacle in this method is separating different types of spent active materials as nano/microsized powders or filter cake. This chapter aims to show the separation of a mixture of cathode and anode active materials by adopting Stokes' law. The focus is on physical separation rather than thermal or chemical separation methods to avoid damaging the morphology and composition of electrode active materials. The proposed model shows how fast and effectively various electrode materials can be separated by adjusting the heavy liquid density. For validation, several experiments are conducted to separate cathode active materials, such as LiCoO2, LiFePO4, LiNi0.8Co0.15Al0.05O2, LiNi1/3Co1/3Mn1/3O2, and LiMn2O4, from anode active materials, such as graphite. Overall, this chapter shows how to rapidly and effectively separate electrode active materials without damaging the morphology and composition of electrode active materials.