POM/CNT based nanohybrids as electrodes for lithium-ion batteries

Polyoxometalates (POMs) and their derivative materials have attracted growing attention for application in energy storage technologies, especially lithium-ion batteries (LIBs). Nanohybrids' redox-active material, based on the combination of polyoxometalates and Carbon nanotubes (CNT), has exhibited suitable structures that have been employed as electrodes in energy devices with enhanced electrochemical performances. The design and construction of POM/CNT nanohybrids linked by covalent bonds act as electron bridges, ensuring close contact between POM and CNT. This facilitates electron and Li-ion transfer, enhancing the overall performance of the electrodes. This review article demonstrated the need for new redox chemistries beyond conventional intercalation mechanisms. This involves the design and application of functional materials for energy storage, focusing on structural change and electron reconfiguration. Even though several reviews on POM-based composites in energy applications exist, a unified and coordinated review dedicated explicitly to these unique and versatile molecular clusters and with CNT nanohybrids in LIB's electrode application has not yet been presented. Hence, we report a comprehensive survey of research advances in POMs and POM/CNT-based nanohybrid materials as electrodes and encompass the discussion of their charge storage mechanism of operation in LIBs. The paper also discusses methods for functionalizing CNTs to improve the electrochemical performance of nanohybrids. These techniques aim to maintain the structural and electronic integrity of CNTs while enhancing their functionality. Finally, the emerging themes and research directions are critically assessed to inspire how these promising nanohybrids can foster research into the next generation of electrodes for sustainable energy technologies.