. 1 Maria Rita Mancini, Recupero di componenti da batterie al litio-ione esauste: processo eco-sostenibile e innovativo, Report RdS/PAR2014/184. Graphite is an industrially important material used in steel industries, foundries, batteries, etc.. Furthermore, graphite-based composites reveal to be promising candidates for the manufacture of high-performance coatings against corrosion and for UV shielding. Natural graphite powders are mainly produced in China, which holds a 70% share of total world production, followed by Latin America with 20%. Europe production of natural graphite powders is less than 1% and therefore graphite was recently listed among the critical raw materials for EU.In this work, we describe an eco-friendly method for recovering graphite powders from anodes of end of life Li-ion batteries. Recovered graphite powders were used as starting material for the sustainable synthesis of graphene, graphene oxide, and reduced graphene oxide. High purity graphene solution was obtained by mild sonication, in ecofriendly solvents, of recovered graphite powders, while graphene oxide was synthetized by modified Hummers’ methods starting from same recovered graphite powders. Reduced graphene oxide (rGO) was obtained by chemical reduction by means of glucose and by thermal treatment in a reducing atmosphere of H2 and Ar at temperatures in the range of 400-900 °C.The proposed synthesis methodologies have been validated applying them to commercial graphite powders. Graphene and graphene oxide films were deposited on fused silica, silicon and yttria stabilized zirconia substrates by spin coating and drop casting techniques, starting from water dispersion of exfoliated graphite and water solution graphene oxide. Thermogravimetical analysis (TGA/DTA), UV-Vis-NIR and FTIR spectrophotometry, XRD, Raman and electron microscope (FE-SEM) measurements were used to investigate solutions, powders and films characteristics. M.R. Mancini 1* , M. L. Grilli 1* , L. Pilloni 1 , M. Falconieri 1 , A. Mancini 2 , L. Petrucci 1 , S. Stendardo 1 1 ENEA Casaccia Research Centre, Via Anguillarese 301, 00123 Rome, Italy 2 ENEA, Frascati Research Centre, Via Enrico Fermi 45, 00044 Frascati (Rome), Italy corresponding authors: [email protected], [email protected] Sustainable syntheses of graphene and graphene oxide from graphite powders recovered by anodes of end of life Li-ion batteries ACKNOWLEDGMENTS The activity was supported by the Italian Ministry of Economic Development in the framework of the Operating Agreement with ENEA for the Research on the Electric System. UV-Vis absorption spectra of graphene obtained by sonication of commercial graphite GRAPHENE SYNTHESIS: via SONICATION assisted Liquid-Phase Exfoliation (LPE) in H2O CONCLUSIONS RECOVERY OF GRAPHITE FROM END OF LIFE Li-ION ANODES Graphene and Graphene oxide were successfully grown by sustainable synthesis starting from commercial and recovered graphite powders. Graphite recovery was carried out from end of life Li-ion batteries with a sustainable and ecofriendly method. This method allows the separation and recovery of all components in the LIBs 1 . Graphene was obtained by sonication of graphite powders in water and/or alcohol. Graphene oxide was prepared by different synthesis based on the modified Hummers’ method. Reduced H 2 SO 4 and KMnO 4 weigth percentage with respect to graphite were used with the aim of speeding up GO purification. Moreover, a new step consisting in the sonication process of the solution before the oxidation, was introduced to promote the exfoliation process. Graphene oxide films were obtained by spin coating and drop casting techniques starting from graphene oxide in water solution. Powders and films were characterized by different techniques and resulted in high quality materials. Graphene H 2 O DISPERSION GRAPHENE OXIDE SYNTHESIS: Modified Hummers’ method: Graphite (commercial and recovered); H 2 SO 4 ; KMnO 4 ; H 2 O 2 ; H 2 O Sonicators Centrifuge a) Graphite soution with H 2 SO 4 and KMnO 4 b) GO in water solution after several washes and centrifugations c) Dried GO and GO solution d) Spin coater for the deposition of GO films on fused silica and Si substrates. SEM micrograph of graphene oxide film deposited by spin coating 2000 1800 1600 1400 1200 1000 900 950 1000 1050 1100 1150 1200 Counts Raman shift (cm -1 ) D-band G-band Raman spectrum of graphene oxide film deposited by spin coating UV-Vis absorption spectra of graphene obtained by sonication of recovered graphite ANODE GRAPHENE CHARACTERIZATION GRAPHENE OXIDE CHARACTERIZATION Recovery of LIBs components were pursued by a simple and eco-friendly process 1 . Graphite, Li and Co are listed among the critical raw materials. Recovered graphite was used for the synthesis of graphene and graphene oxide. Sonochemical process Spent lithium ion batteries Dissasembling to cells Separation of Graphite ANODE from Cu Collector Graphite Flakes a b c d SEM micrograph of graphene oxide flakes UV-vis absorption spectrum of GO solution obtained from recovered graphite ANODE SEM micrograph of graphene oxide from recovered graphite ANODE UV-vis absorbance spectrum of GO solution RAMAN spectra of graphite flakes, dried GO and rGO XRD spectra of Grafite flakes and dried GO 1000 1250 1500 1750 2000 2250 2500 2750 3000 Counts (a.u.) Raman Shift (cm -1 ) Graphite Flakes Graphene Oxide Reduced Graphene Oxide D-band G-band 2D-band 250 300 350 400 450 500 550 600 0.0 0.2 0.4 0.6 0.8 1.0 1.2 Absorbance (nm) C=C n- C A B Separator tape Flash *Steel *Plastic Cathodic tape Anodic tape Spent LIBs Discharging CO 2 Recovered Electrolyte Degassing Separating CO 2 Supercritical Dismanting and separating Electrolyte extraction Solvents + PVDF Recovered active Materials Recovered collectors PVDF dissolution Solvents Recovered PVDF PVDF dissolution SONICATION Filtration/ purification AGENZIA NAZIONALE PER LE NUOVE TECNOLOGIE, L’ENERGIA E LO SVILUPPO ECONOMICO SOSTENIBILE Recovered Graphite Separation of tape: Anode, Cathode and Separator Recovery of LIBs components 250 300 350 400 450 500 550 600 0.15 0.20 0.25 0.30 Sonication 60min 90min Absorbance Wavelength (nm) 268nm Recovered Graphite Anode from Lithium ion batteries (LIBs) 5 10 15 20 25 30 35 40 45 50 55 60 Intensity (a.u.) 2 Graphite Flakes Graphene Oxide 200 250 300 350 400 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Absorbance Wavelenght (nm) Graphite Sonication 10 min 15 min 268 nm