2026 Chen Bioleaching critical metals from spent lithium ion batteries

In recent years, owing to the extensive application of lithium-ion batteries (LIBs) in large-scale energy storage, transportation systems, and portable electronics, the LIB market has expanded rapidly. Proper recycling of spent LIBs can significantly alleviate environmental and economic burdens. Bioleaching, as an environmentally friendly and cost-effective approach for metal recovery from primary and secondary resources, is particularly suitable for the processing of spent LIBs. However, its efficiency significantly decreases under high-pulp-density conditions. Therefore, improving metal recovery performance under such conditions remains a critical challenge. This review systematically summarizes the microorganisms and leaching strategies employed for LIB bioleaching in the related peer-reviewed publications from 2015 to 2025, which were retrieved from the Web of Science, Scopus, and ScienceDirect databases. Based on this, this review analyzes the mechanistic limitations under high-pulp-density conditions and elucidates the key factors responsible for reduced efficiency. Furthermore, several process-intensification strategies are discussed, along with future perspectives for industrial-scale application. The increasing market demand and rapid technological development in LIB recycling highlight the strong potential of bioleaching technologies. This review provides mechanistic insights into microbial recovery processes and offers guidance for future research on high-pulp-density bioleaching systems.