The use of lithium-ion batteries (LIBs) has been increasing, and effective recycling strategies need to be developed. Bioleaching, which uses microorganisms to solubilize metals, is a promising, environmentally friendly alternative to conventional (pyro- and/or hydrometallurgy-based) metal recovery techniques. However, bioleaching has not yet been applied to recycle LIBs on an industrial scale. A low-waste closed-loop bioleaching-based technology was developed for cobalt (Co) recovery from an active cathode material (LiCoO2; LCO). The system involved generation of sulfuric acid in an acid-generating bioreactor (AGB) containing an adapted acidophilic prokaryotic consortium, 2- to 3-week leaching of LCO with the biogenic acid (pH 0.9), selective precipitation of Co hydroxide, and recirculation of the raffinate back into the AGB. In total, 58.2% and 100% of the Co and Li, respectively, were solubilized in seven phases, and >99.9% of the dissolved Co was recovered after each phase. Additionally, Co electrowinning was optimized as an alternative recovery technique, yielding high recovery rates (91.1% and 73.6% on carbon felt and roughened steel, respectively) from bioleachates that contained significantly lower Co concentrations than industrial hydrometallurgical liquors. The closed-loop system was dominated by the mixotrophic archaeon Ferroplasma, followed by the sulfur-oxidizing bacteria Acidithiobacillus (At.) caldus and At. thiooxidans. The developed system achieved high Co recovery rates and provided high-purity solid products suitable for a battery supply chain while minimizing waste production and the inhibitory effects of elevated concentrations of dissolved metals on the leaching prokaryotes. The system is suitable for scale-up applications and has the potential to be adapted to different battery chemistries.