Recovery of valuable metals from waste cathode materials of spent lithium-ion batteries using mild phosphoric acid

Xiangping Chen; Hongrui Ma; Chuanbao Luo; Tao Zhou

doi:10.1016/j.jhazmat.2016.12.021

Recovery of valuable metals from waste cathode materials of spent lithium-ion batteries using mild phosphoric acid

J Hazard Mater. 2017 Mar 15:326:77-86. doi: 10.1016/j.jhazmat.2016.12.021. Epub 2016 Dec 12.

Authors

Xiangping Chen¹, Hongrui Ma², Chuanbao Luo³, Tao Zhou³

Affiliations

¹ School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an 710021, PR China; College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China. Electronic address: chenxiangping101@163.com.
² School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an 710021, PR China. Electronic address: mahr@sust.edu.cn.
³ College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China.

PMID: 27987453
DOI: 10.1016/j.jhazmat.2016.12.021

Abstract

Sustainable recycling of valuable metals from spent lithium-ion batteries (LIBs) may be necessary to alleviate the depletion of strategic metal resources and potential risk of environmental pollution. Herein a hydrometallurgical process was proposed to explore the possibility for the recovery of valuable metals from the cathode materials (LiCoO₂) of spent LIBs using phosphoric acid as both leaching and precipitating agent under mild leaching conditions. According to the leaching results, over 99% Co can be separated and recovered as Co₃(PO₄)₂ in a short-cut process involved merely with leaching and filtrating, under the optimized leaching conditions of 40°C (T), 60min (t), 4 vol.% H₂O₂, 20mLg^-1 (L/S) and 0.7mol/L H₃PO₄. Then leaching kinetics was investigated based on the logarithmic rate kinetics model and the obtained results indicate that the leaching of Co and Li fits well with this model and the activation energies (Ea) for Co and Li are 7.3 and 10.2kJ/mol, respectively. Finally, it can be discovered from characterization results that the obtained product is 97.1% pure cobalt phosphate (Co₃(PO4)₂).

Keywords: Leaching; Phosphoric acid; Recovery; Spent lithium-ion batteries; Valuable metals.