Rare-Earth-Based Metal-Organic Frameworks for Electrochemical Energy Applications: Current Status and Emerging...

Rare-earth-based metal-organic frameworks (RE-MOFs) have increasly emerged as a distinctive class of functional materials for electrochemical energy storage and conversion. The unique coordination chemistry of rare-earth ions, including high coordination numbers, shielded 4f electronic configurations, strong Lewis acidity, and accessible multivalent redox states in selected elements, endows RE-MOFs with exceptional framework stability, distinct redox functionality, and enhanced interfacial reactivity. This review comprehensively covers recent advances in RE-MOF-based materials for batteries, supercapacitors (SCs), and electrocatalysis. We first elucidate the fundamental coordination chemistry of rare-earth ions to establish the origins of their electrochemical functionality. We then focus on design strategies such as framework engineering, composite construction, and thermal transformation, emphasizing structure-property-performance correlations that link molecular-level features to macroscopic behavior. We critically assess key challenges, including mechanistic ambiguities, limited conductivity, scalability, and sustainability concerns. Finally, we propose future research directions, highlighting advanced characterization, artificial intelligence for accelerated discovery, systematic exploration of the lanthanide series, and sustainable preparation routes. This integrated perspective aims to guide the rational design and practical implementation of RE-MOFs for sustainable electrochemical energy technologies.