Multifunctional and ultrastrong MXene modified aramid fibers

Two dimensional (2D) materials have been extensively used in applications such as energy storage, solar steam generation, power generation, and water purification. Among these 2D materials, Ti3C2Tx MXene is one of the most popular candidates for energy storage applications because of its outstanding electrical and electrochemical properties. However, its applications are restricted due to the insufficient mechanical properties of pure MXene architectures caused by weak inter-sheet assembly. One potential supporting substrate used to impart mechanical integrity to MXene architectures is aramid yarn, however, one drawback of this lightweight and strong material is its lack of surface functionality, inhibiting MXene adhesion. To solve this issue, air plasma was utilized to impart hydroxyl groups to the fiber, enabling MXene to be deposited through a simple dip coating method. Upon 35 layers of MXene coating, the resulting composite fiber becomes a promising electrode material for supercapacitors demonstrating outstanding energy density (18.51 μWh cm−2) and low electrical resistance (0.4 kΩ cm−1) while retaining excellent tensile strength (3.28 GPa). Furthermore, the composite fiber can be also integrated into wearable Joule heating devices as it provides human body temperature heating with 7 V voltage applied.