Recovery of lithium from Li-ion battery leachate by gas-liquid precipitation

Today Li-ion battery recycling processes allow the recovery of heavy metal elements such as copper, cobalt, nickel and manganese. On the other hand, lithium is generally lost in slag or released to the environment and therefore is not recovered. Lithium is an element non-substitutable of Li-ion batteries which technology is indispensable in electromobility and energy transition. Moreover, since 2020 the EU has classified lithium as a “critical metal”.

The objective of this work is to develop a precipitation process of lithium salts from spent Li-ion batteries (LIBs), which respects the environment, consumes little energy and material, by maximizing the yield and purity of the product obtained. Experimental procedures in batch and continuous reactors made possible to optimize operating parameters such as temperature, solid concentration inside the reactor, reaction time and stirring speed.

Lithium carbonate and lithium hydroxide are the preferred precursors for synthetizing LIBs since they deliver high purity in the final product, and the most important are cost effective. Shin e al. (2022) [1] In this work the precipitation of Li₂CO₃ is performed. Lithium carbonate exhibits inverse solubility thus, the more the temperature increases, the residual content of dissolved lithium decreases and therefore the quantity of precipitated lithium carbonate increases. From the experiments a suitable set-up of the process is presented as well as a novel route for the precipitation of lithium salts by direct carbonation. This allows to improve the purity and yield of the precipitate.