Microfluidic large-scable construction of ultra-strong MXene-ANFs@PPy core-shell microfiber for wearable high-energy-density supercapacitors

Constructing advanced structural fiber with high energy density is pivotal for wearable power-supply application of fiber-based supercapacitors (FSCs), but it usually sacrifices the mechanical property. Herein, we develop ultra-strong MXene-aramid nanofibers@polypyrrole core–shell (MXene-ANFs@PPy) fiber in large scale via microfluidic spinning strategy, where ANFs can provide abundant hydrogen-bond networks between MXene nanosheets, and in-situ interfacial coupling of PPy on MXene-ANFs fiber can ensure interconnected porous channels and sufficient active sites. Therefore, the MXene-ANFs@PPy fiber maintains large mechanical property (strength: 168 MPa, strain: 1.7%), straightway ions diffusion dynamics and luxuriant faradaic charge accumulation. Accordingly, the MXene-ANFs@PPy fiber delivers high specific capacitance of 1487 F cm - 3 and good rate performance (1006 F cm - 3 at 10 A cm - 3 ) in 1 M H 2 SO 4 . The MXene-ANFs@PPy based solid-state FSCs exhibit high energy density of 9.54 mWh cm −3 , long-term cycling stability (92% initial capacitance after 10,000 cycles) and outstanding bending stability, which can be woven into clothes to achieve wearable self-powered prototype. Our work offers a novel strategy for large-scale construction of high-performance fiber electrode and accelerates the progress of wearable electronics.