Hydrometallurgical Extraction of Li and Co from LiCoO2 Particles–Experimental and Modeling

Abstract

The use of lithium-ion batteries as energy storage in portable electronics and electric vehicles is increasing rapidly, which involves the consequent increase of battery waste. Hence, the development of reusing and recycling techniques is important to minimize the environmental impact of these residues and favor the circular economy goal. This paper presents experimental and modeling results for the hydrometallurgical treatment for recycling LiCoO2 cathodes from lithium-ion batteries. Previous experimental results for hydrometallurgical extraction showed that acidic leaching of LiCoO2 particles produced a non-stoichiometric extraction of lithium and cobalt. Furthermore, the maximum lithium extraction obtained experimentally seemed to be limited, reaching values of approximately 65–70%. In this paper, a physicochemical model is presented aiming to increase the understanding of the leaching process and the aforementioned limitations. The model describes the heterogeneous solid–liquid extraction mechanism and kinetics of LiCoO2 particles under a weakly reducing environment. The model presented here sets the basis for a more general theoretical framework that would describe the process under different acidic and reducing conditions. The model is validated with two sets of experiments at different conditions of acid concentration (0.1 and 2.5 M HCl) and solid to liquid ratio (5 and 50 g L−1). The COMSOL Multiphysics program was used to adjust the parameters in the kinetic model with the experimental results.

A Green and Efficient Solvent for Simultaneously Leaching Co and Li from Spent Li-Ion Batteries: Dicarboxylated Polyethylene Glycol

“…During the leaching process, the reduction of Co (III) to Co (II) was also observed in Figure . Because dcPEG used here was not oxidized (Figure ), the reduction of dcPEG was excluded, and H 2 O produced by the active H atoms may act as the reductant. ,, Therefore, the leaching reaction might include the following steps: (1) ion exchange; (2) dissolution reaction; and (3) reduction for Co (III) . The leaching reaction mechanism is summarized in Scheme .…”

“…The reaction process of LiCoO 2 powder with dcPEG belongs to typical liquid–solid noncatalytic reaction. The shrinking core (SC) model is usually employed to reveal this type of reaction. − In this model, the reaction is triggered by the external surface of the particle. The unreacted solid will shrink and diminish during the dissolving process.…”

“…During the leaching process, the chemical reaction-controlled and internal diffusion-controlled steps are the typical rate-controlling steps. If the largest barrier for the leaching process is the internal diffusion, the models can be described by the following: As the leaching process is controlled by the surface chemical reaction, the model is described as The Avrami model, , a mixed control model, needs to be considered if the process combined with the reaction and the diffusion. It can be expressed as follows: where k is the kinetic rate constant, X is the extraction efficiency, t is the leaching time, and N is the adjustable parameter.…”

Cobalt Electrochemical Recovery from Lithium Cobalt Oxides in Deep Eutectic Choline Chloride+Urea Solvents

“…We also studied the underlying mechanism of the extraction of cobalt and lithium using a typical shrinking core model [11d,25] . As depicted in Figure 2, the LCO particle in the DES can be viewed as a sphere comprising an undissolved core and an outer surface structure (product layer) in contact with the stagnant film of the DES solvent.…”

Literature Review, Recycling of Lithium-Ion Batteries from Electric Vehicles, Part I: Recycling Technology

“…On the contrary, Mn, graphite, and Li can be effectively recycled by hydrometallurgical processes. Nonetheless, there are still many issues of this procedure, such as F recovery, Mn recycling control, the production of graphite products, or the sensitiveness to organics compounds that easily contaminate process water [38,44].…”