A comparative life cycle assessment of disposal and recycling pathways for spent lithium-ion battery electrolyte

While lithium-ion batteries (LIBs) are crucial for global decarbonization, the management of their hazardous organic electrolyte represents a critical yet frequently overlooked bottleneck in the circular economy. Containing lithium hexafluorophosphate (LiPF6) salt dissolved in flammable carbonates, the electrolyte poses severe safety risks through thermal instability and toxic hydrogen fluoride emissions, while its energy-intensive synthesis makes its destruction a significant resource loss. This study addresses this gap by providing a rigorous ‘gate-to-gate’ life cycle assessment (LCA) of four end-of-life (EOL) pathways: direct disposal (incineration, chemical neutralization) and recycling (vacuum pyrolysis, distillation extraction). Modeled in SimaPro using the Ecoinvent 3.9 database, the analysis of a 100-litre functional unit of LiPF6 electrolyte reveals a definitive environmental performance hierarchy driven by the quality and functionality of recovered materials. Distillation extraction, enabling a high-purity closed-loop, was uniquely identified as providing a net environmental benefit with a climate change credit of – 2.46 kg CO2 eq. Conversely, incineration emerged as the most detrimental option (+11.29 kg CO2 eq.) due to extreme energy demands and hazardous residue generation. The findings empirically demonstrate that non-destructive chemical recovery is fundamentally superior to energy-oriented downcycling, providing a quantitative framework to prioritize high-value circularity in future battery regulations and industrial investments.