Decarbonizing transport through circular battery solutions: life cycle impacts of hydrometallurgy vs pyrometallurgy in NMC battery recycling

The accelerating adoption of electric vehicles (EVs) has triggered unprecedented demand for lithium-ion batteries (LIBs), forcing an urgent reckoning with end-of-life (EoL) management and material recovery. Existing research, though expanding rapidly, often treats recycling technologies in generalized terms and fails to account for the influence of varying battery chemistries on environmental outcomes. Despite extensive reliance on life cycle assessment (LCA) frameworks, the literature has yet to deliver a robust comparative evaluation of recycling technologies across the spectrum of nickel–manganese–cobalt (NMC) chemistries. Hydrometallurgical and pyrometallurgical routes are frequently discussed, but their impacts are seldom examined through a chemistry-specific lens using a consistent methodological framework. The present study directly addresses this gap by conducting a comparative LCA of hydrometallurgical and pyrometallurgical recycling processes for four NMC battery chemistries—NMC 111, 523, 622, and 811, using ReCiPe 2016 midpoint (H) in OpenLCA v2.4 with Ecoinvent v3.10. A 300 kg EV battery pack is modeled, incorporating sensitivity analysis (renewable vs. fossil energy) and Monte Carlo-based uncertainty analysis. Results show hydrometallurgical recycling offers superior environmental performance, with a 24.4 % lower climate change impact and notable reductions in human toxicity (−4380.56 kg 1,4-DCB-eq for NMC 811). Pyrometallurgical methods exhibit higher burdens in energy use and carcinogenic effects. Integrating renewables further improves outcomes. The study delivers chemistry-specific evidence that advances sustainable recycling strategies while providing policymakers and industry leaders with critical guidance to align technology choices with the demands of a truly circular battery economy.