Sustainable recovery of high-valued resources from spent lithium-ion batteries: A review of the membrane-integrated hybrid approach

Lithium-ion batteries (LiBs) can play a vital role in the stable transition towards a renewable and low-carbon society by replacing fossil fuel-based power sources in transportation, electronics, and energy storage devices. In future, a surge in electric vehicle adoption is expected, which will result in a high demand for LiBs, accumulation of spent LiBs, and challenges in supplying critical metals for battery industries. The sustainable management of abandoned LiBs can be achieved via urban mining to protect the environment from LiB disposal and conventional mining. Currently, <5% of decommissioned LiBs are recycled into valuable resources. Therefore, a paradigm shift in recycling processes is required to change the current recycling status at ground level. Hydrometallurgical processes are most commonly used to leach precious metals (Li, Co, and Ni) from solid to aqueous phases. However, the complete recovery from a leached solution is challenging. This membraneintegrated hybrid approach can facilitate the development of an efficient, eco-friendly, and cost-effective method for the downstream separation and recovery of valuable metals from spent LiBs. This review presents a comprehensive literature survey on the recycling of valuable metals from spent LiBs and further directs research on new membrane-based sustainable approaches to enhance value recovery. A tailor-made membrane in an appropriate module, can be easily integrated with conventional processes to achieve a high degree of process intensification during recovery and boost the scale-up confidence and circular economy approach.