High performance of stretchable carbon nanotube-polypyrrole fiber supercapacitors under dynamic deformation and temperature variation

Flexible fiber-shaped supercapacitors have great potential in wearable electronic devices. Here, we fabricate CNT-PPy composite films by an electrochemical deposition method from macroscopic CNT films. The composite films are transformed into flexible fibers with ultralow density by drawing through several diamond wire-drawing dies. The CNT-PPy fibers have outstanding electrochemical properties with a high specific capacitance of 302 F g −1 in 1 M H 2 SO 4 liquid electrolyte. Flexible, stretchable, all-solid-state, fiber-shaped supercapacitors are then fabricated from the CNT-PPy fibers using H 3 PO 4 -poly(vinyl alcohol) as gel electrolyte. The supercapacitor has a high specific capacitance of 69 F g −1 , a high power density and an energy density of 3.8 kW kg −1 and 3.6 W h kg −1 , respectively. The fiber-shaped supercapacitor also exhibits high stability and reliability under static and dynamic stretching, and also in a wide temperature range from −27 °C to 61 °C. Fiber-shaped supercapacitors (FSSCs) are fabricated from CNT-PPy composite networks. The FSSCs exhibit outstanding capacitive performance with a high specific capacitance of 69 F g −1 . The FSSCs are stable and reliable under static and dynamic stretching, and wide temperature variation.