An Advanced Anode Composed of Layered Single‐Crystal Metal–Organic Framework Material for Ultra‐Long Cycle‐Life Sodium‐Ion Batteries

Abstract Developing advanced anode materials for sodium‐ion batteries (SIBs) is a frontier and hotspot research for clean and sustainable electricity energy storage and conversion. However, it is still challenging to obtain anode materials with high stability, multiple active sites, and high conductivity. In this paper, an advanced metal–organic framework (MOF)‐based anode material (Co‐HITP), which integrates multiple advantages into one, is successfully synthesized through a sodiation‐stimulated in situ reconstruction. The Co‐HITP possesses a stable single‐crystal structure, expanded spacing layers, abundant sites, and good conductivity, and exhibits superior properties with ultra‐long cycling stability (ultralow decay rate ≈0.001% per cycle after 15 000 cycles at 8 A g⁻¹), high reversible capacity (450.1 mA h g⁻¹ at 0.2 A g⁻¹), and excellent rate performance. Both experimental results and theoretical calculation reveal that the anode remains a stable structure after long cycling, attributed to the single‐crystal structure with d‐π hybridization and π–π interaction, and the minimum structural unit stores 6Na⁺ ions of C═N sites and 8Na⁺ ions of aromatic rings. This discovery is significant for developing advanced anode materials with integrated advantages for SIBs.