As they increase in age, degradation processes occur in lithium ion batteries. These processes can lead to a significant reduction in range depending on the battery and vehicle. Most vehicle manufacturers guarantee a service life of at least eight years or 160,000 kilometers with more than 70 percent of the original storage capacity (state-of-health). Some vehicle manufacturers are now even increasing these guarantees. Current studies and long-term tests show that the net capacity after the guarantee period is usually well above the values specified by the manufacturer. Vehicles with a reduced range can still be used for a long time even after the guarantee period has expired. Eventually, however, after a certain number of charging cycles depending on use, lithium-ion batteries will reach a state in which they no longer meet the requirements of the car. The majority of these batteries are recycled and the raw materials are returned to the material cycle for the production of new batteries. Depending on their condition, some of the old batteries could be eligible for reprocessing and reuse in battery-electric vehicles (remanufacturing) or in second-life applications such as stationary battery storage systems. When they have finally reached the end of their useful life, the new EU Battery Regulation stipulates recycling quotas and minimum quantities of reused raw materials in new production. The industry must find the most efficient solutions possible for returning them to the material cycle, especially since the volumes of batteries returned will increase significantly in the future. The aim is to achieve a sustainable, CO₂-neutral battery production along the entire process chain with unlimited reuse of materials in a closed product life cycle. This is intended to minimize waste products and dependence on important primary materials.