Valorization of resources from end-of-life lithium-ion batteries: A review

The increase in the number of lithium-ion batteries (LIBs) on the market in the last decades, boosted by the increasing popularity of electric vehicles, has led to high extraction and use rates of raw materials. LIBs contain scarce materials, mostly in concentrations higher than in natural ores. Nonetheless, large scale recycling processes of LIBs focus mainly on valuable materials (e.g., Ni and Co). Graphite from anodes is currently not reclaimed. In addition, LIB recycling facilities use energy and resource-intensive technologies based on pyro- and hydrometallurgy. Accordingly, recycling routes need to be improved to guarantee lower environmental impacts and more efficient recovery rates. In this context, this study examines the functioning of LIBs, their composition, main benefits and drawbacks related to the technology, and existing recycling processes for value recovery from LIBs. New approaches for resource valorization from LIBs are described, including biohydrometallurgy, resynthesis of electrodes, and production of metal-organic frameworks and graphene-based materials from cathodes and anodes. Fragilities and potentialities to manage end-of-life batteries are also discussed. Most studies found in the literature focus on LiCoO2 cathodes and the most innovative investigations targeting automotive batteries are still limited to the lab-scale phase. In the future, the economic aspects and environmental impacts of these technologies require further assessment.