Induction heating as a pre-treatment for the recycling of Li-ion battery cathodes – Technical feasibility

Abstract

Production capacities for lithium-ion batteries are being expanded globally to meet the rising demand for energy storage applications. However, high scrap rates represent a key challenge for the production of lithium-ion batteries, especially for electrode manufacturing. The recycling of cathode production scraps that occur as intermediate products in electrode manufacturing offers a good possibility to reuse valuable battery active materials and close the material cycle within the production line. In this work we develop a novel method based on electromagnetic induction to separate cathode coating and aluminum foil. A cathode coil rejected from production was cut into sheets which were inductively heated to 300, 400 and 550 °C. The thermally pre-treated sheets were stressed in a cutting mill. With this method the coating could be separated from the foil up to 99.12 %. The aluminum impurities in the recycled fine powder fraction could be kept at a low level of 0.27 wt.-% at maximum. Agglomerates in the powder fraction could be significantly reduced through the thermal pre-treatment. This work shows the feasibility of induction heating as an energy-efficient and flexible thermal pre-treatment for the recycling of roll-to-roll cathode materials.