Influence of the used solvent on the efficiency of the extraction of cathode materials for direct recycling

Lithium-ion batteries are playing an increasingly significant role in modern mobility and energy storage. Their increasing quantity and the limited amount of material resources available on earth will place great demands on the most efficient recycling in the future. In this paper, we focused on the first stage of the so-called direct recycling, i.e. the extraction of electrode material from the current collector, using six types of solvents in combination with three types of the most commonly used cathode materials in lithium-ion batteries. Three selected lithium-ion batteries were aged for 500 cycles and disassembled for the next step - cathode material extraction. The extraction was carried out by a method that is least energy intensive, cost effective and preserves the structural stability of the cathode materials after extraction. Of the used solvents, Dimethylacetamide (DMAC) was found to be the most effective solvent for the extraction. At the same time, Dimethylsulfoxide (DMSO) was the most effective solvent in terms of solvents considered to be biologically harmless. The study also included an analysis of the degradation of the cathode materials after their extraction from the current collector. It was found that all materials remained stable for even one month after the extraction.