CHEMICAL ENGINEERING TRANSACTIONS VOL. 41, 2014 A publication of The Italian Association of Chemical Engineering www.aidic.it/cet Guest Editors: Simonetta Palmas, Michele Mascia, Annalisa Vacca Copyright © 2014, AIDIC Servizi S.r.l., I SBN 978-88-95608-32-7; I SSN 2283-9216 Leaching Optimization of Battery Black Mass for Lithium Recovery by Electrochemical Junction Transfer (ETJ) Technology Elodie Guyot a , Clotilde Boulanger* a , Jean-Marie Lecuire a  a Université de Lorraine – CNRS UMR 7198, 1 Bd Arago CP 87811, 57078 Metz cedex 1, France  The work described herein constitutes one last research projects with Jean-Marie’s active involvement. We are honored to be able to share authorship with him one more time. clotilde.boulanger@univ-lorraine.fr A process of cation recovery based on intercalation properties into host matrix has been previously developed in the laboratory. It consists in a selective extraction from a waste electrolyte (battery leachates, industrial effluents…) to a recovery electrolyte, separated by an Electrochemical Junction Transfer (ETJ). The ETJ is constituted of a porous material coated by an active matrix (LiMn 2 O 4 ). The transfer from synthetic electrolytes like Li 2 SO 4 was successfully carried out whereas the transfer from real waste (spent Li-ion batteries leachate) was problematic. First studies by cyclic voltammetry confirmed a limited behaviour and showed that the blockage could be attributed to 2 phenomena: the presence of organic compounds coming from Li-ion battery components and the acidity of leachates during transfer. The goals of our work were to eliminate these organic compounds and to define the optimized pH range for an efficient transfer. Different methods (chemical treatment on leachates or thermal treatment directly on crushed battery Black Mass) for removing organic compounds were performed. After a thermal treatment on Black Mass (T = 500 °C, t =72 h) and a pH adjustment (pH = 5), the selective transfer of Lithium was carried out with a faradic yield close to 100%. 1. Introduction At present time, our modern life extensively uses portable, thin, light equipment (cellular phones, laptop, remote controllers, digital cameras…) with batteries as power sources. In most cases, lithium-ion secondary battery (LiB) technology has been applied because it delivers high power capacity. Tomorrow, it could also become crucial for electric vehicles. Consequently the numbers of LiBs are set to grow in the future as are the volumes of used equipment and batteries that need recycling. This recycling is essential to avoid harmful substances in the environment and to recover some valuable elements having scarce natural resources. Two classes of processes, including physical processes (mechanical, thermal, mechanochemical) and chemical ones (acid/base leaching, bioleaching, solvent extraction, precipitation, electrochemical process) have been applied for the recovery of cobalt and lithium, one of the primary objectives in the recycling of spent LiBs as presented in the review of Xu et al. (2008). These processes aim to apply a funnel principle where every non-wished element is extracted one by one, using the classical chemical reactions until the desired element remains. We proposed another approach using an electrochemical transfer junction (ETJ), allowing a selective extraction of the desired metallic cation between two electrolytes (Seghir et al., 2008, Seghir et al. 2010a, Seghir et al., 2010b; Guyot et al. 2013). The process is based on insertion/de-insertion reactions in a host- Lattice (HL) (Potel et al., 1984; Schöllhorn, 1980). The ETJ is constituted of a porous ceramic material coated by an active matrix. The global phenomenon of intercalation, diffusion, de-intercalation represented by [HL]  + xne - + xM n+  [MxHL]  allows the transfer of mobile cationic species from a medium to the other one through the ETJ. The advantages of this electrochemical process are the use of non-polluting reagents and a limited number of steps while their drawback is a reactivity limited at the electrode DOI: 10.3303/CET1441012 Please cite this article as: Guyot E., Boulanger C., Lecuire J.M., 2014, Leaching optimization of battery black mass for lithium recovery by electrochemical junction transfer (etj) technology, Chemical Engineering Transactions, 41, 67-72 DOI: 10.3303/CET1441012 67