Recovery of lithium from spent lithium-ion batteries (LiBs) using carbochlorination

YARIVITH GONZÁLEZ PEÑA; JORGE GONZÁLEZ; ORIANA BARRIOS TORRES; LUCÍA BARBOSA

Antofagasta

Workshop; 7 th International Workshop on Lithium, Industrial Minerals and Energy,; 2020

Universidad de Antofagasta

The technological advancement of the electromobility industry and the switch to alternativeenergies have led to an increase in the demand of lithium-ion batteries. This increase has alsogenerated an increase in spent lithium-ion batteries (LiBs). In this context, the methodologies fortreating this type of waste and particularly those focusing on recovering valuable metals such aslithium take great importance and pave the way to circular economy. This approach enables theindependence from nonrenewable resources and emphasizes the eco-sustainability. [1,2]Here, we studied an alternative treatment for spent lithium-ion batteries (LiBs) through thepyrometallurgical process of carbochlorination using chlorine gas as chlorinating agent andcommercial carbon as reducing agent. The cathode material extracted from the LiBs (composedmostly of LiCoO2), previously subjected to a calcination pretreatment at 400°C for 40 min, wasused as the reactant solid. The solid reactant mixture (MSR) was composed of LiCoO2 andcarbon in proportions of 75/25% w/w, respectively. The gases used for the tests were 99.5% v/vchlorine and 99.99% v/v nitrogen. The reaction was controlled by thermogravimetry in athermogravimetric system suitable for working in corrosive atmospheres [3,4].The treated sample was washed filter and dried. After these process, a soluble product (PS) andan insoluble product (PNS) were obtained. Both products were characterized by X-raydiffraction (XRD). The LiCl phase was detected in the PS diffraction pattern and the Co3O4phase in the PNS diffraction pattern (Fig 2). These results agree with reaction 1. Therefore, it canbe deduced that, under the time and temperature conditions studied, carbochlorination of thestructure of the reactive material of the cathode (LiCoO2) occurs, forming LiCl and Co3O4.The analyzes show that the resulting carbochlorination is an alternative way of extracting thelithium present in the cathodic material of LIBs as a soluble compound (LiCl) at 400°C. Othervariables are currently being studied, such as reaction time, temperature, type of carbon, fluxes.of Cl2; among others.