Evaluating the toxic potential of lithium-ion battery black mass

Abstract

Over the past decade, the exponential growth of the battery industry has led to an increased propensity for battery recycling. During the recycling process, cathode materials such as LiCoO2 (LCO) or LiNixMnyCozO2 (NMC) are fragmented into smaller counterparts which can pose as inhalational risks. However, the risks of exposure from these particles have not been well-established yet. Furthermore, there exists a need to select a suitable cell line for toxicology studies of these particles to better replicate the human lung in vivo cytotoxic response. The dose-dependent relationship and cell-particle interactions of zinc oxide nanoparticles (ZnO-NPs) were first evaluated in two well-established human lung epithelial cells, A549 and Calu-3. A549 showed a better representation of primary cell line cytotoxic response compared to Calu-3. Hence, A549 cells were used in the later part of the project to establish the toxicity profile of LCO and NMC. A549 cells showed decreasing viability upon treatment with either LCO or NMC particles. Intracellular reactive oxygen species (ROS) formation and presence of DNA damage were also investigated in this study. The results showed that exposure to LCO and NMC significantly induced ROS formation as well as DNA damage in A549 cells. This study reports that LCO and NMC induce cytotoxic and genotoxic responses in A549 cells. Hence, this requires authorities to strictly regulate the recycling process, especially in occupational settings to minimize the exposure of these particles.