Multiscale Dot‐Wire‐Sheet Heterostructured Nitrogen‐Doped Carbon Dots‐Ti3C2Tx/Silk Nanofibers for High‐Performance Fiber‐Shaped Supercapacitors

Abstract Fiber‐shaped supercapacitors (FSCs) have become one of the significantly strategical flexible energy‐storage materials towards future wearable textile electronics and metaverse technologies. Here, we develop the high‐performance FSCs based on multiscale dot‐wire‐sheet heterostructure microfiber of nitrogen‐doped carbon dots‐Ti 3 C 2 T x /silk nanofibers (NCDs‐Ti 3 C 2 T x /SNFs) hybrids via microfluidic fabrication. Due to the enlarged interlayer spacing, plentiful porous channels, accelerated H + ion transport dynamics, large electrical conductivity and excellent mechanical strength/flexibility, the NCDs‐Ti 3 C 2 T x /SNFs possesses high volumetric capacitance (2218.7 F cm −3 ) and reversible charge–discharge stability in 1 M H 2 SO 4 electrolyte. Furthermore, the solid‐state FSCs present high energy density (57.9 mWh cm −3 ), good capacitance (1157 F cm −3 ), long‐life cycles (82.3 % capacitance retention after 40000 cycles), which realize the actual energy‐supply applications (powering lamp, watch and toy car).