Lithium recovery by electrochemical transfer junction based on intercalation host matrix E. Guyot, S. Seghir, S. Diliberto, J.-M. Lecuire, C. Boulanger ⁎ Institut Jean Lamour, Université de Lorraine, CNRS, 1 Bd Arago, F-57078 Metz, France abstract article info Article history: Received 10 June 2012 Received in revised form 25 June 2012 Accepted 25 June 2012 Available online 4 July 2012 Keywords: Intercalation Oxides Chevrel phases Lithium recovery Li-ion battery Electrochemical transfer junctions (ETJs) were synthesized via a chemical covering method onto a porous ceramic substrate (mullite/alumina). This layer of 100 μm is composed of lithium metal oxides. The ETJ composites placed between two tanks lead to a lithium transfer by intercalation reactions by applying a current density between electrodes placed in both tanks. After proving the transfer efficiency, we combined this transfer with another one relative to cobalt ions with a Chevrel phase matrix in order to propose a one step process to recover simultaneously but separately both Li and Co cations. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Our modern life extensively uses portable, thin, light equipments (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 capac- ity. Tomorrow, it could also become crucial for electric vehicles. Conse- quently 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 pri- mary objectives in the recycling of spent LIBs as presented in the review of Xu [1]. These processes aim to apply a funnel principle where every non-wished element is extracted one by one, using the classical chem- ical reactions until the desired element remains. We proposed another approach using an electrochemical transfer junction (ETJ), allowing a selective extraction of the desired metal between two electrolytes [2,3]. The process is based on insertion/de-insertion reactions in a Mo 6 X 8 matrix [4–8]. Recently the cation fluxes through ETJ were enhanced via a Mo 6 X 8 covering (100 μm) onto a porous ceramic sub- strate (mullite/alumina) [9]. 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 interface, and not in the bulk of solution. The cathode materials in LiBs are made of lithium intercalation materials: oxides Li x M y O z with M = Co, Ni, Mn, V, Ti or phosphates Li x MPO 4 , with M = Co, Fe [10] acting into organic electrolytes. Since these oxides intercalate also lithium in aqueous medium, they could be used in ETJs for re- covering lithium. The present work was to experimentally demon- strate the validity of a lithium withdrawal through oxide (LiCoO 2 and LiMn 2 O 4 ) junctions by electrolysis in aqueous solution. The paper reports the control of cation fluxes for different applied cur- rent densities. The influence of Co 2+ , cation present in battery leach- ates was studied for the matrix presenting the best extraction performances. Finally, in galvanostatic conditions and by using two different ETJs (LiMn 2 O 4 , Mo 6 S 8 ), the simultaneous extraction of lith- ium and cobalt cations in two different electrolytes, was established. 2. Experimental LiCoO 2 and LiMn 2 O 4 compounds allowing an ionic intercalation via electron/ion transfer were chosen as materials for ETJ. They were synthe- sized by reaction of stoichiometric mixtures of Li 2 CO 3 and CoCO 3 (Alfa Aesar) or MnCO 3 (Sigma Aldrich). The mixture of analytical grade pre- cursors (>99.9%) was calcined for 8 h at 680 °C for LiCoO 2 and at 800 °C for LiMn 2 O 4 to yield the desired oxide powders. Cu 3 Mo 6 S 8 pow- der was obtained by the solid state reaction (1000 °C, 50 h) of a well-homogenized stoichiometric mixture of Cu, MoS 2 and Mo fine pow- der according to the method described [4]. The de-intercalation of copper of Cu 3 Mo 6 S 8 was carried out chemically (HCl 6 M) or electrochemically (at 0.400 V/SCE for 420 min) and led to Mo 6 S 8 . Porous ceramic sub- strates (diameter: 24 mm, thickness: 1 mm, surface: 4.5 cm²) were syn- thesized from a mixture of kaolin and alumina developing a porosity Electrochemistry Communications 23 (2012) 29–32 ⁎ Corresponding author. Tel.: +33 387 315 465; fax: +33 387 315 460. E-mail address: clotilde.boulanger@univ-lorraine.fr (C. Boulanger). 1388-2481/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.elecom.2012.06.031 Contents lists available at SciVerse ScienceDirect Electrochemistry Communications journal homepage: www.elsevier.com/locate/elecom