Innovation in rare earths recycling: A quantitative and qualitative analysis of patent data

Rare earth elements (REE) are currently essential enablers of the digital and decarbonization transition. However, their supply chain is highly concentrated and their extraction has a high environmental impact. Circular economy solutions could provide a double benefit, reducing supply risk for import-dependent countries and mitigating the impacts of REE mining. This article focuses on REE recycling and provides a comprehensive global overview of innovation dynamics in this sector using patent data. We propose a two-step patent search methodology to identify REE recycling patents, based on the OECD ENV-TECH classification for green technologies and keyword occurrence. We then develop a set of quantitative and qualitative metrics to explore innovation dynamics at the country, applicant and technology type level. China clearly emerges as the most attractive market for REE recycling patents and Chinese universities as the most active applicants worldwide. Conversely, patent applications in all other countries showed stagnating trends over the last decade. In particular, Europe has a lower number of both patent applications and patents developed compared to the US and Japan. However, patent quality indicators show a very different picture: US and Japanese applicants, who appear to be at the technological forefront, receive more citations and are more oriented towards protecting their inventions internationally. Our analysis therefore highlights the importance of considering both quantitative and qualitative patent metrics when examining innovation trends in REE recycling. We discuss the determinants of these observed phenomena, draw policy implications - particularly for REE import-dependent countries - and propose avenues for future research at the intersection of CRM, the circular economy, and innovation studies. • Search methodology to identify REE recycling patents. • China is by far the most attractive market for REE recycling inventions protection. • Chinese applicants are the most productive but patent quality is relatively low. • US, Japan and, especially, the EU must catch-up to improve REE circularity.