applications because they can be integrated into textiles or be made elastic if the fiber electrodes are resilient to bending, stretching, and twisting. [7][8][9][10][11][12] To power electronics, FSCs require high electrical conductivity and high energy storage performance from the fiber electrodes. In hybrid fiber electrodes that comprise of at least one active material and a binder, these electrode properties are dependent upon the amount of active material (loading) and how well the two components are mixed. It is also important that the method of production can be made scalable and continuous. To date, however, a continuous and scalable production of fiber electrodes with high electrical conductivity and energy storage performance remains a challenge. One example of fiber fabrication is via a deposition technique that involves coating of active materials onto a conductive fiber substrate. [13][14][15][16][17][18] This method is simple and scalable to achieve FSC electrodes with active material loading of up to ≈30 wt%. [13,14] Another fiber fabrication example is biscrolling technique, which can trap active materials onto the helical corridors of carbon nanotube (CNT) sheets. [19][20][21][22][23][24][25] This method is suitable for making tens of centimeters long fiber electrodes with very high active material loadings (>90 wt%). Wet-spinning is an industrially viable approach to fiber production and has therefore attracted considerable attention for the fabrication of various FSC electrodes, such as graphene fibers, [26][27][28] CNT fibers, [29][30][31] and conducting polymer fibers. [32][33][34] In wet-spinning composite formulations containing an active material and a binder, the two components must be homogeneously dispersed to achieve "spinnablility" into long continuous fibers. Also, the two components must not limit the function of the other component particularly at high active material loading. The high conductivity and electrochemical performance of the active material must be maintained (for use as electrodes) and the binder must provide durability and flexibility (for continuous production).Ti 3 C 2 T x is one of the growing family of 2D early-transition metal carbides/carbonitrides (MXenes), which shows great promise for application in FSC electrodes. [14,35,36] Besides its high conductivity (up to 9880 S cm −1 ), [37] Ti 3 C 2 T x MXene has an exceptionally high capacitance (up to 1500 F cm −3 ) [38] that comes predominantly from the intercalation/deintercalation of H + and surface redox Fiber-shaped supercapacitors (FSCs) are promising energy storage solutions for powering miniaturized or wearable electronics. However, the scalable fabrication of fiber electrodes with high electrical conductivity and excellent energy storage performance for use in FSCs remains a challenge. Here, an easily scalable one-step wet-spinning approach is reported to fabricate highly conductive fibers using hybrid formulations of Ti 3 C 2 T x MXene nanosheets and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate....

Tremendous efforts have been dedicated towards high-performance energy storage devices though material innovation, nanoscale structural design and hybrid fabrication approaches. A crucial technique to tune the properties of nanomaterials, such...

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