The main aim of this work was to test the ability of an amino acid (i.e. glycine) to leach cobalt from Li ion batteries (LiBs). The process parameters namely temperature, pulp density and concentration of glycine. ••Glycine in the presence of H2O2 leached Co from spent Li ion batteries.••. Lithium-ion batteries (LiBs) are widely used as power source in mobile phones, computers and other modern life gadgets. LiBs are preferred due to their unique characteristics, s. 2.1. LiBs samples and pre-treatmentMobile phone batteries (Li ion batteries) were procured from SIMS recycling solutions, based in Eindhoven, the Netherlands. Th. 3.1. Total metal characterization of the cathodic materials (LiBs)The results of the total metal characterization of the LiBs sample are mentioned in Tab. 4.1. Spent lithium ion batteries, a potential resource of CoThis study shows that spent LiBs can be used as a potential resource of critical metals, particular.