In a world driven by increasing mobile energy demand, the proper management of end-of-life (EoL) batteries has become an urgent priority. This presentation introduces the long-lasting relation between H.C. Starck Tungsten (HCS) and battery materials, as well as its current efforts to implement a sustainable recycling of black masses – a product of lithium-ion battery recycling containing most of the critical raw materials (Li, Ni, Co, graphite). The presented initiative focusses on developing an innovative and resource-efficient hydrometallurgical process to transform black mass into different battery grade chemicals and the subsequent upscaling to pilot and production scale. It will be shown how innovative approaches towards lithium separation and solvent extraction can help to overcome hurdles inherent to state-of-the-art technologies and process routes.