title: Environmental friendly leaching reagent for cobalt and lithium recovery from spent lithium-ion batteries.
abstract: We investigated an environmentally friendly leaching process for the recovery of cobalt and lithium from the cathode active materials of spent lithium-ion batteries. The easily degradable organic acid DL-malic acid (C(4)H(5)O(6)) was used as a leaching reagent. The structural, morphology of the cathode materials before and after leaching were characterized by X-ray diffraction (XRD) and scanning electronic microscopy (SEM). The amount of Co and Li present in the leachate was determined by atomic absorption spectrophotometry (AAS). Conditions for achieving a recovery of more than 90 wt.% Co and nearly 100 wt.% Li were determined experimentally by varying the concentrations of leachant, time and temperature of the reaction as well as the initial solid-to-liquid ratio. We found that hydrogen peroxide in a DL-malic acid solution is an effective reducing agent because it enhances the leaching efficiency. Leaching with 1.5M DL-malic acid, 2.0 vol.% hydrogen peroxide and a S:L of 20 g L(-1) in a batch extractor results in a highly efficient recovery of the metals within 40 min at 90 °C.
authors.affiliation: School of Chemical Engineering and the Environment, Beijing Key Laboratory of Environmental Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Jing
authors.initials: J
authors.lastname: Ge
authors.forename: Renjie
authors.initials: R
authors.lastname: Chen
authors.forename: Feng
authors.initials: F
authors.lastname: Wu
authors.forename: Shi
authors.initials: S
authors.lastname: Chen
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: Zhang
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D011211:Electric Power Supplies; D059029:Electronic Waste; D055772:Green Chemistry Technology / Q000379:methods*; D006861:Hydrogen Peroxide / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D008293:Malates / Q000737:chemistry*; D059027:Recycling / Q000379:methods*; D013696:Temperature
chemical_list: D008293:Malates; D003035:Cobalt; C030298:malic acid; D008094:Lithium; D006861:Hydrogen Peroxide