Chapter 19 - LIB industry waste valorization for battery production

Abstract

Hydrometallurgy is a versatile, flexible, and industrially feasible process to simultaneously address waste battery recycling, e-waste management, and environmental challenges for the circular economy of battery metals and sustainable waste battery recycling. We have developed a closed-loop industrial hydrometallurgical process for valorizing lithium-ion battery (LIB) industry waste for use in battery manufacturing, which is discussed in this chapter. Through a sequential combination of hydrometallurgical techniques like leaching-solvent extract-scrubbing-(precipitation) stripping, a process for 5N pure cobalt recovery from LIB industry waste has been developed. First, cobalt is extracted by acid leaching; then, from the leach liquor, cobalt is separated/purified by solvent extract using saponified Cyanex 272. From cobalt-loaded Cyanex 272, residual lithium is scrubbed by Na2CO3 solution. Finally, cobalt is recovered by precipitation stripping via two routes, (1) as cobalt sulfate and (2) as cobalt oxalate. Cobalt oxide, which can be used in battery production, is synthesized and characterized from the cobalt oxalate. The cobalt oxalate precipitate is calcined to synthesize Co3O4, a precursor for LIB manufacturing. TGA-DTA followed by XRD analysis has confirmed the conversion of CoC2O4·2H2O to anhydrous CoC2O4 at 200°C, anhydrous CoC2O4 to Co3O4 at 350°C, and Co3O4 to CoO at 1100°C. In general, the valorization process can circularize waste LIBs for the LIB manufacturing process through a versatile and flexible industrial approach.