Separation and recovery of the active material from Cu foils in lithium-ion battery anodes by electrohydraulic fragmentation using pulsed discharge

Abstract

The increasing demand for lithium-ion batteries (LIBs) has led to a significant rise in the amount of spent LIBs, necessitating efficient recycling methods to recover valuable materials from the cathodes and anodes. Furthermore, the efficient recycling of graphite anodes (GA) from LIBs has become an important economic and environmental concern because GAs account for nearly 10% of the total production cost. This paper reports on the separation and recovery of GA material and copper (Cu) foil from LIB anode sheets made from in-process end materials that have not been immersed in electrolyte, which mimics in-process scrapped anodes, by performing electrohydraulic fragmentation (EHF) using the pulsed discharge. The previous study of life cycle assessment indicated that the separation method conducted by the discharge involves lower energy consumption and environmental impact. The objective of this study is to experimentally determine the optimal voltage and number of discharge shots for high separation rates of GA particles with low Cu contamination. The results indicate that 5–7 discharge shots at 14–20 kV are useful for separation and satisfy the required conditions for anode recycling, providing a material recovery rate of more than 95% and a Cu concentration of less than 1.0 wt%. The size of the recovered GA particles was smaller, and the size distribution was narrower as the discharge voltage of EHF increased. This study suggests that EHF is a useful and novel method for the separation from the LIB cathode, which is required in the recycling process.