Mitigating the disproportionate environmental impacts and costs of dysprosium in Nd-Fe-B magnets through material efficiency

Ultra-high-grade neodymium‑iron‑boron (Nd-Fe-B) magnets are essential components of clean energy technologies, including electric vehicles and wind turbines. However, they often contain dysprosium (Dy), a heavy rare earth whose extraction poses environmental, social and supply risks, and which is classified as a critical raw material by the European Union. Reducing Dy content while maintaining the magnetic performance required for these applications, enabled by material efficiency techniques, is therefore a critical step toward a sustainable energy transition. This study quantifies the life cycle environmental impact and raw material costs of manufacturing Nd-Fe-B magnets containing 1–8 wt% Dy. We modelled Nd and Dy as distinct upstream supply chains in the magnet life cycle. The results reveal that despite its low content, Dy contributes disproportionately to environmental impacts (e.g., 78% of freshwater ecotoxicity, 75% of marine eutrophication, and 78% of land use, for a baseline magnet composition with 4 wt% Dy), as well as magnet materials costs (25–44%). Reducing Dy content from 4 to 1 wt% would prevent the leaching of 480–840 kg of ore, avoid 12–17 kg CO₂-eq, reduce the fifteen other environmental impacts assessed by 11 to 64%, and save around €10 per kilogram of magnet. At the system level, without material efficiency (baseline 4 wt% Dy), cumulative Dy demand for magnets in a net-zero emissions scenario would be equivalent to two-thirds of present reserves by 2050. Limiting Dy content in magnets, whose technical feasibility has been demonstrated, represents a crucial solution to mitigate resource depletion, reduce environmental impacts and lower costs.