Fully conjugated porous framework towards high-capacity cathodic sodium storage and stable organic full cell

Conjugated microporous polymers (CMPs) for sodium-ion storage have gained increasing attention owing to their outstanding stability, varied topologies, and intrinsic porosity. However, constructing organic cathodes with high theoretical capacity, long cycle life, and excellent conductivity for Na⁺ storage remains a formidable challenge. This study presents a conjugated skeleton (TAPQ-CMP) as an organic cathode material for sodium-ion batteries (SIBs). Due to its abundant active sites and fully conjugated structure, the TAPQ-CMP delivers extremely high initial capacity (455 mAh/g at 0.05 A/g) and remarkable long cycle life (maintaining 152 mAh/g at 10.0 A/g after 5000 cycles). The storage mechanism is elucidated through a combination of density functional theory calculations and a series of in/ex-situ characterizations. Furthermore, the construction of Na-HC//TAPQ-CMP full cell exhibits an outstanding energy density of 358 Wh/kg at 0.1 A/g. Even at a current density of 5 A/g, the full cell retains a robust capacity of 200 mAh/g_cathode after 3500 cycles, representing one of the best comprehensive performances among recently reported organic-based electrodes. More importantly, the constructed soft-packed full cell exhibits excellent stability under different bending states and pragmatic value, indicating that TAPQ-CMP stands out as a practical material for efficient sodium-ion energy storage systems. © 2025 Elsevier B.V.