Evaluation of recycling routes for mixed chemistry lithium-ion batteries : a life cycle approach

Abstract

The transition to electrified transport has generated a rapidly growing end-of-life (EoL) stream of lithium-ion battery (LIB) packs requiring responsible management. This thesis evaluates and compares the environmental performance of two representative industrial recycling routes for mixed-chemistry LIB waste using life cycle assessment (LCA). Route A involves mechanical pre-treatment followed by hydrometallurgical processing, while Route B involves mechanical pre-treatment followed by pyrometallurgical smelting and hydrometallurgical refining. An analysis with gate-to-gate approach is performed for 1kg of the material from the end of its life (EoL) of the lithium-ion battery (LIB) as functional unit, with openLCA 2.6.1 and the cut-off database ecoinvent 3.10 together with impact assessment method for Environmental Footprint 3.1. Finnish industrial parameters are applied throughout. Four battery chemistry scenarios are modelled: S0 (100% nickel manganese cobalt oxide (NMC) 111), S1 (100% NMC811), S2 (70% NMC/30% Lithium Iron Phosphate (LFP), and S3 (40% NMC/60% LFP). The results on climate change (GWP100), freshwater ecotoxicity (CTUe) and terrestrial acidification are reported. In the scenarios of low-carbon usage of the grid, the net negative impact of recycling appears successful in both scenarios, demonstrating that meaningful benefit can be realised with regards to using and recycling primary metal. Route B base case has an environmental impact between 0.18–0.22 kg CO₂-eq (≈7–8% in the NMC-dominant scenarios, rising toward 10% at high LFP) per kg FU higher than that for Route A. The contribution of LFP to the overall environmental benefit is not significantly changed with increased LFP content on both routes, and the relative ranking remains unchanged. The performance gap is reduced but not closed by the Route B slag leaching sensitivity variant, which meets all the EU Battery Regulation material recovery targets (including lithium recoveries at 2027) which are set in Article 71 of the Regulation.