Recycling lithium-ion batteries (LIBs) is imperative for securing the future demand for raw materials required for the electrification of economies worldwide. The technical challenges of recycling at a large scale involve minimizing the value loss of materials, addressing the complexity of standardization, and reducing environmental impacts. This research aims to support the development of more sustainable LIB recycling methods by utilizing bacterial biological reactions to recover manganese from spent LIBs, aligned with the principles of green chemistry. The present study describes an optimized bioseparation method to recover manganese from spent LIBs (lithium manganese oxide – LMO/ lithium nickel manganese cobalt oxide – NMC) as manganese carbonate (MnCO₃) with a uniform, spherical morphology, using an engineered strain of S. oneidensis MR-1.