Characterisation of fire-damaged batteries – implications for recycling

As lithium-ion battery demand grows, so do fire safety challenges. Despite this, research on fire-damaged batteries remains limited. This study explores the distribution of valuable metals (such as Ni, Mn, Co, Cu) in two types of waste derived from lithium-ion nickel-manganese-cobalt oxide batteries (NMC811): black mass (BM) and fire-damaged waste (FD). It emphasizes that cobalt, manganese, and nickel-rich NMC particles are predominantly found in smaller particle size fractions (<125 µm), where they can account for up to 85% of total metal content. Fire-damaged (FD) batteries show a similar, though less pronounced, trend. Evidence of structural degradation suggests that fire temperatures exceeded 500 °C; however, the presence of residual organic binders indicates that heat was unevenly distributed during the fire. FD batteries become friable and easily fragment into fine particles, which can hinder the effective separation of copper and aluminium current collectors, increasing their presence in processed material. The inclusion of FD batteries in standard BM processing introduces variability in output composition, potentially lowering the concentration of high-value NMC811 materials present. To maintain product quality and recycling output values, it is recommended that FD batteries are processed separately. Alternatively, particle size separation may allow for tailored outputs aligned with specific customer requirements.