Insights into the Eco-Friendly Recovery Process for Valuable Metals from Waste Lithium-ion Batteries by Organic Acids Leaching

ABSTRACT

The extensive use of lithium-ion batteries (LIBs) has generated a huge amount of their wastes. As waste, LIBs can be used as a source for valuable metals such as lithium, cobalt, manganese, and nickel. Like the ores of these metals, their values are recognized as raw material. This can ultimately help bring down the cost of LIB production while reducing their harmful environmental impacts. As a result, recycling has become a major opportunity for industrialists and a challenge to environmentalists all across the globe. Researchers have explored various methods to recover cobalt and lithium precious metals from worn out batteries. This review provides an overview of the recent technological solutions on the recovery from waste LIBs using organic acids-based hydrometallurgical processes concerning chemical reactions, structures, and leaching efficiency with different organic acids. Subsequently, the advantages of organic acids over inorganic acid have also been discussed with an emphasis on possible complex formations during the recovery process. At last, the potent role of process variables: reductant concentration, reaction time, temperature, solid:liquid ratio, and concentration of complexing agent during the Co and Li leaching has been discussed along with prospects in this research area.

Graphical abstract

KEYWORDS:

• lithium-ion batteries
• organic acid leaching
• hydrometallurgical process
• recycling
• e-waste

Abbreviations

LCO, Lithium Cobalt Oxide; LFP, Lithium Iron Phosphate; LIBs, Lithium-ion batteries; LiCoO_2, Lithium Cobalt Oxide; LMO, Lithium Manganese Oxide; NCA, Lithium Nickel Cobalt Aluminum oxide; NMC, Lithium Nickel Manganese Cobalt oxide; NiMH, Nickel Metal Hydride; NMP, N-methyl-pyrrolidone; S:L ratio, solid to liquid ratio; WEEE, Waste electronic and electric equipment

Acknowledgments

V. Chaudhary thanks Mr. Raman Sharma, Director, Exigo Recycling Pvt. Ltd., New Delhi for financial support. P. Lakhera thanks to ICMR, New Delhi for the senior research fellowship award from grant number 5/3/8/38/ITR-F/2020-ITR. Director CSIR-CSIO is acknowledged for providing necessary infrastructure facilities. KHK acknowledges the support made by a grant from the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (Grant No: 2016R1E1A1A01940995).

Disclosure statement

No potential conflict of interest was reported by the authors.