Early-Stage Recovery of Lithium from Tailored Thermal Conditioned Black Mass Part I: Mobilizing Lithium via Supercritical CO2-Carbonation

Abstract

In the frame of global demand for electrical storage based on lithium-ion batteries (LIBs), their recycling with a focus on the circular economy is a critical topic. In terms of political incentives, the European legislative is currently under revision. Most industrial recycling processes target valuable battery components, such as nickel and cobalt, but do not focus on lithium recovery. Especially in the context of reduced cobalt shares in the battery cathodes, it is important to investigate environmentally friendly and economic and robust recycling processes to ensure lithium mobilization. In this study, the method early-stage lithium recovery (“ESLR”) is studied in detail. Its concept comprises the shifting of lithium recovery to the beginning of the chemo-metallurgical part of the recycling process chain in comparison to the state-of-the-art. In detail, full NCM (Lithium Nickel Manganese Cobalt Oxide)-based electric vehicle cells are thermally treated to recover heat-treated black mass. Then, the heat-treated black mass is subjected to an H2O-leaching step to examine the share of water-soluble lithium phases. This is compared to a carbonation treatment with supercritical CO2, where a higher extent of lithium from the heat-treated black mass can be transferred to an aqueous solution than just by H2O-leaching. Key influencing factors on the lithium yield are the filter cake purification, the lithium separation method, the solid/liquid ratio, the pyrolysis temperature and atmosphere, and the setup of autoclave carbonation, which can be performed in an H2O-environment or in a dry autoclave environment. The carbonation treatments in this study are reached by an autoclave reactor working with CO2 in a supercritical state. This enables selective leaching of lithium in H2O followed by a subsequent thermally induced precipitation as lithium carbonate. In this approach, treatment with supercritical CO2 in an autoclave reactor leads to lithium yields of up to 79%.

Comparative Study for Selective Lithium Recovery via Chemical Transformations during Incineration and Dynamic Pyrolysis of EV Li-Ion Batteries

“…Another method to improve Li leachability can be with the use of supercritical CO 2 as reported in [20], where Li efficiency was 79%.…”

“…Therefore, the addition of excess graphite did not have a significant effect on the leaching of Li. Another method to improve Li leachability can be with the use of supercritical CO2 as reported in [20], where Li efficiency was 79%.…”

Environmentally Friendly Recovery of Lithium from Lithium–Sulfur Batteries

“…Therefore, environmentally friendly methods were investigated to reach a carbonation of lithium by aqueous leaching and CO 2 -reaction. In [20], this was investigated for lithiumion batteries, reaching lithium mobilization in the form of a solid lithium carbonate of up to 64% by aqueous leaching only. By treating the black mass and H 2 O suspension with supercritical CO 2 (>73.8 bar [21]), a lithium recovery by 79% could be proven.…”

“…In [20], the possible, underlying mechanisms for CO 2 -supported lithium carbonation in aqueous media were discussed in detail, so a detailed elaboration of the chemical formula is not included in this paper.…”

Contributions of extended batch tests for assessing technical recyclability: A case study of low‐value battery flows

“…Given the increasing share of low‐value lithium batteries in the main waste flow, the separation of cobalt‐ and nickel‐rich battery subsystems is one possible measure to increase the recovery rate of Co and Ni from the main waste flow in established recycling processes. The result is a waste flow containing various low‐value subsystems subjected to alternative and cost‐effective recycling processes, such as thermal treatment (Lombardo et al., 2020; Schwich et al., 2021).…”