Pseudocapacitive Behavior of S/Se‐Functionalized Abnormal N ‐Heterocyclic Carbene‐Based Zinc Complexes for Flexible Micro‐Scale Energy Storage

Supercapacitors, especially micro‐supercapacitors for on‐chip integration in flexible/wearable electronics, are efficient storage devices for intermittent renewable energy sources, bridging the gap between batteries and conventional capacitors by offering high power density, rapid charge–discharge rates, and long cycle life. However, achieving superior electrochemical performance at the molecular scale remains a challenge. Here, we report the synthesis of four unprecedented zinc complexes ( 1 –4 ) incorporating sulfur‐ and selenium‐functionalized abnormal N ‐heterocyclic carbene ligands, highlighting the unexplored potential of molecular coordination complexes as active materials for micro‐supercapacitors ( 1–3 ). All complexes were characterized by single‐crystal X‐ray diffraction, UV–vis, IR, and Raman spectroscopy, XPS, and thermogravimetric analysis, confirming their distinct structural and electronic properties. Electrochemical studies reveal that complexes 1–3 exhibit significant pseudocapacitive behavior with good charge storage capability and cycling stability. Complex 2 delivered the highest areal capacitance of 8.149 mF cm ⁻² , followed by complexes 3 and 1 , respectively. The micro‐supercapacitor device based on complex 3 achieved the highest capacitance retention (108.78%) after 1050 cycles, indicating a highly reversible electrochemical process. This work demonstrates the synthesis, characterization, and stable pseudocapacitive performance of S/Se‐functionalized carbene–Zn complexes for energy storage applications.