Recycling of LIB: A New Separation Process for Lithium Ion Electrodes and Electrode Production Scraps

Abstract

The increasing demand of lithium ion batteries (LIBs), especially from growth in electric vehicle (EV) production, presents the need for recovery of active materials from spent lithium ion batteries and production rejects. To prevent a future shortage of lithium and other valuable raw materials, development of recycling processes for both the spent LIBs and the production rejects becomes crucial.In contrast to existing recycling processes, the main goal of the presented process (Fig. 1) is to achieve a high recycling yield and to recover battery materials at battery grade quality. Lithium and electrolyte components should be recycled in addition to copper, cobalt and nickel.The project spams the entire recycling process starting from the discharging and disassembly stages, and following through with mechanical, chemical and thermal processing (e.g. crushing, grinding, classification, sorting, and extraction) used to separate the battery into recyclable fractions.In order to match the high purity standards of hydro-metallurgical processes for the production of battery active materials, the battery active materials have to be separated from the current collector foil very purely (Fig. 2).For this purpose, a new separation process has been developed: Adhesion Neutralization via Incineration and Impact Liberation (ANVIIL). Firstly, a thermal degradation of the polyvinylidene fluoride (PVDF) binder of the electrodes is induced by heat under different atmospheres. Secondly, a new separation apparatus is used to apply impact stress on the electrode compounds to separate coating from foil and to integrate a fine classification step.Using this separation process separation rates of over 99 % are reached. Furthermore, the separated coating can be re-gained with a very low contamination of aluminum from scraps of the current collector of under 0.1 % w/w. Subsequently, new battery active materials have been produced and characterized in battery test cells.