Engineering Ion Transport Highways Through Polyoxometalate‐Functionalized Metal−Organic Frameworks for Solid‐State Lithium Batteries

Abstract Solid‐state lithium metal batteries offer superior safety and energy capacity; however, their practical implementation remains severely limited by lithium (Li) dendrite formation and growth. Metal‐organic frameworks (MOFs) demonstrate significant efficacy in regulating Li + distribution for dendrite suppression. Nevertheless, inherent energy barriers within MOF channels substantially impede ion transport efficiency. Here, polyoxometalate‐functionalized MOFs (MOF@POM) is demonstrated as a novel strategy to enhance Li + screening and diffusion. The lithiophilic characteristics of POMs facilitate reduced energy barriers for Li + conduction across interfaces and through MOF pores. Furthermore, POMs, functioning as negatively charged entities, minimize anion‐lithium interactions, thereby promoting enhanced ion transport. While the MOF architecture provides precisely oriented ion channels for directed deposition, POMs enable low‐energy Li + diffusion pathways, effectively suppressing dendrite formation. The engineered MOF@POM interface exhibits exceptional ionic conductivity and reduced activation energy compared to conventional interfaces. Consequently, batteries incorporating MOF@POM interfaces demonstrate remarkable cycling stability. These findings elucidate the fundamental role of POMs in dendrite suppression within MOF structures, providing critical insights for advancing lithium metal anode battery technology.