Wet vs dry mechanical recycling process – an outlook for anodic active material recycling

Designing a sustainable production chain for Li-ion batteries (LIBs) represents a crucial step in the energy transition. The challenge of establishing electromobility as a green technology involves developing recycling processes that increase the recirculation of materials. Several industrial LIBs recycling processes reported in the literature combine mechanical, thermal and chemical treatments. The main processes currently developed focus recovering the metals from the cathode side due to their scarcity and economic value. On the other hand, graphite, as the active material in the anode, is also crucial, representing 12 to 21wt% of the battery. Nevertheless, processes to increase the recovery of this material are currently not receiving much attention. Separating active materials from current collectors is challenging since this step is heavily dependent on the binder. Commonly used binders for anode are carboxymethylcellulose (CMC) and styrene-butadiene (SBR). Both water-soluble, making them ecologically and economically attractive, not only from a manufacturing point of view, but also for recycling process. In this context, this work proposes to add wet process steps to the conventional dry recycling route and to compare the black mass obtained by this process with the material obtained by the classic dry route. The material obtained is characterized using different techniques, e.g. inductively coupled plasma optical emission spectrometry (ICP-OES) to measure the concentration of impurities generated by copper current collectors and concentration of Li on the different fractions“;“ scanning electron microscope (SEM) images and Raman spectroscopy to determine particle morphology and quality of the graphite structure, respectively. Overall it will be shown that by the integration of wet processes the impurities can be significantly reduced.