Intercalating <scp>PANI</scp> Nanoparticles Into <scp>Ti₃C₂T_x MXene</scp> Fiber to Construct Open Ion Diffusion Channels for High‐Performance Flexible One Dimensional Supercapacitors

ABSTRACT Owing to the high conductivity, abundant active sites, and large packing density, two‐dimensional materials Ti 3 C 2 T x MXene flakes serve as a promising material to assemble flexible electrode for wearable electronics system. However, the intrinsic self‐restacking feature of two‐dimensional material still remains a pivotal issue that impedes fascinating electrochemical performance. Here, we assemble a flexible fiber‐shaped supercapacitor (F‐SC) based on polyaniline (PANI) hybridized Ti 3 C 2 T x (PT) fiber using a wet spinning process. The existence of PANI nanoparticles between the two‐dimensional sheets can enhance the layer distance significantly and restrain the layer restacking effect, leading to a large surface area, good ion diffusion kinetics, and rich adsorption sites. Additionally, PANI can effectively create a stable interface interaction between adjacent Ti 3 C 2 T x fiber, constructing smooth electron migration pathways. As a result, the PT fiber presents excellent specific capacitance (200.7 F g −1 at 1 A g −1 ) and rate performance (86.5 F g −1 at 10 A g −1 ). Notably, the fabricated symmetric F‐SC appears to have a favorable energy density of 2.5 Wh kg −1 , considerable mass capacitance of 88.7 F g −1 at 0.1 A g −1 and good mechanical endurance (bending 180 o ), which shows a bright future in wearable application.