Project Portugal 2030

Summary

The main objective of the Li-cycle project is to develop a process for an effective carbon-free lithium recovery from Li-ion batteries (LIBs). Currently, the recycling of LIBs is extremely limited, and lithium is the last element to be recovered after a series of precipitation steps. Li-cycle aims to recover over 80% of lithium present in the black mass leachate (KPI 1), which is a very ambitious target set by the EU, well above of currently achievable 40-60%. This will be achieved by developing and investigating, by experimental and modelling integrated approach, 1) novel lithium selective polymeric membranes, 2) deep eutectic solvent (DES)-based flow electrodes, and 3) their integration into an electricity-driven lithium-membrane flow capacitive deionisation (Li-MFCDI) device, which will be used to recover lithium from LIBs’ mass black leachate directly and as the first element recovered. The objectives for the membranes to be prepared are to attain selectivity values above 50 for Li/Mn (KPI 2), Li/Co (KPI 3), Li/Cu (KPI 4) and Li/Ni (KPI 5). This is at least 5 times above the current selectivity values given by the monovalent Neosepta CIMS membrane. Furthermore, simultaneously, lithium flux must be above 0.5 mol/(m2.h) (KPI 5). The cost of the membrane is aimed at below 200 €/m2 (KPI 6), which is much lower than the price of ceramic membranes from OHARA company (200 000 €/m2). Finally, the membrane should be stable at pH=1 (KPI 7) and when in contact with deep eutectic solvent (DES) (KPI 8) which will be used to prepare flow electrodes. Those should have conductivity higher than 5 mS/cm (KPI 9), be stable above 2 V (KPI 10) and have viscosity lower than 50 cP (KPI 11) at a shear rate of 200 s-1. It will be the very first time that non-aqueous-based flow electrodes will be used either in traditional flow capacitive deionization or for Li-MFCDI. The energy consumption at Li-MFCDI will be aimed at less than 0.25 kWh/m3 (KPI 12), which is similar to the one already reported by us, and around 5 times lower than in a chloro-alkali process coupled with lithium recovery. The aimed capacity of the Li-MFCDI stack to be developed will be to treat 15 L of leachate per hour (KPI 13). The objectives and work planned are ambitious and the Li-cycle project aims to advance significantly beyond the state-of-the-art, with associated risks mitigated by a contingency plan for each task (Table 1). The development of FCDI and Li-MFCDI are in their infancy, thus there are several aspects in this project with strong innovation potential, such as the rational development of advanced materials, use of new electrolytes, optimisation of the process, advanced characterisation techniques and modelling approaches. Furthermore, young researchers, such as two postdoctoral researchers and one PhD student, will be formed during this project. Besides, we will accept master’s students to work on the project. The results will be made known to the scientific community through 7 articles in international peer-reviewed scientific journals, as well as through participation in at least 9 conferences, meetings, and workshops. One patent is planned to be submitted. Furthermore, we aim to intensify our contacts with industry and society, based on the exploitation plan, to alert them not only about the need for more sustainable use of energy but also about the need for recycling prime materials and the advantages of implementing herein proposed approach.