Indirect bioleaching for metal recovery from battery black mass using microbially generated acid from a secondary sulfur resource

Recycling critical metals from spent lithium-ion batteries (LIB) has attracted significant attention in recent years, driving the search for more sustainable and environmentally friendly recovery methods. Among emerging approaches, indirect bioleaching may be a very promising alternative for recovering valuable metals from spent LIB. In this study, sulfuric acid (H2SO4) was produced by using a mixed culture containing Acidithiobacillus thiooxidans, and various dosing methods were examined to assess their impact on the leaching efficiency of lithium cobalt oxide (LCO), nickel manganese cobalt (NMC) oxides, and industrial black mass. The results demonstrated that the bioleaching strategy effectively enhanced metal recovery, highlighting the viability of utilizing microbially generated acid from secondary sulfur resources as a cost-effective and sustainable solution for the recovery of critical metals from spent batteries. This investigation provides new insights into the role of indirect bioleaching in addressing the challenges of resource recovery and environmental sustainability in the context of battery recycling.