Sustainable recycling of lithium-ion batteries: Biometallurgical approaches for the recovery of critical raw materials

The European battery market is currently experiencing strong growth, with production capacity fo-recast to reach up to 1,200 GWh by 2030 in optimistic scenarios. At the same time, the European Union is calling for mandatory recycling quotas to ensure strategic independence from critical raw materials used in batteries. Currently, valuable metals such as copper, cobalt and nickel are recover-ed from lithium-ion battery recycling primarily through hydrometallurgical processes using strong inorganic acids. However, these processes are associated with significant environmental challenges, as they produce toxic by-products, high salt loads, which are difficult to dispose of, and harmful gases such as CO2 and SO2. In contrast, organic acids offer a more environmentally friendly alterna-tive to the leaching process, promising high recovery rates as well as environmental and economic benefits. However, the economic implementation of these processes is still difficult. A promising solution may lie in biometallurgical processes, which provide a sustainable alternative for high recovery of critical metals. Initial studies show that biometallurgical processes, both direct and indi-rect approaches using Gluconobacter oxydans (DSM 3504) and Acidithiobacillus thiooxidans (DSM 504), achieve efficient mobilization rates for valuable metals (e.g. >94% Mn) at room tempe-rature and within 7 days. These processes therefore represent a potentially more environmentally friendly and economically attractive alternative.