Circular Input Rate: novel indicator to assess circularity performances of materials in a sector - Application to rare earth elements in e-vehicles motors

A smarter and sustainable mobility is key for a carbon-neutral and circular Europe, although electrification will require a massive supply of critical materials. Circular strategies can support the transition by maximizing the materials' value and through effective actions, which however require an adequate monitoring framework. To assess materials' circularity in a given sector, the novel Circular Input Rate (CIR) indicator is proposed and applied to rare-earths in e-motors' permanent magnets to monitor recent progresses of circular strategies and estimate their effects in future scenarios. Results prove that the CIR effectively captures the contribution of all circular strategies: in 2030, reuse and remanufacturing can keep in the loop about 90tons of Nd, to be added to 161tons of secondary Nd from functional recycling (captured by the EOL-RIR indicator). In future research, the CIR could be tested to assess materials' circularity in other sectors, which also will allow to better understand its limitations and potentials.