Recycling valuable materials from the spent lithium ion batteries to catalysts: methods, applications, and characterization

As the prevailing technology for energy storage, the extensive adoption of lithium-ion batteries (LIBs) inevitably results in the accumulation of numerous spent batteries at the end of their lifecycle. From the standpoints of environmental protection and resource sustainability, recycling emerges as an essential strategy to effectively manage end-of-life LIBs and reclaim valuable elements within them. Hydrometallurgy, closely intertwined with catalysis, stands as a relatively mature strategy for achieving high-value utilization of spent LIBs. In this review, our emphasis is placed on the interconnected themes of catalysis within the realm of hydrometallurgical recycling. Specifically, we delve into the crucial role that catalysis plays in both the recycling process of LIBs and the sustainable utilization of their extracted materials in various catalytic applications. This focused exploration aims to contribute insights into the intricate relationship between catalysis and the broader context of LIB recycling, shedding light on its pivotal role in achieving both environmental sustainability and functional material repurposing. Moreover, we highlight advanced characterization techniques, represented by surface-sensitive enhanced Raman spectroscopy, to fundamentally understand the reaction mechanism of catalysts, which, in turn, would inform more rational catalyst designs.