High performance stretchable fibrous supercapacitors and flexible strain sensors based on CNTs/MXene-TPU hybrid fibers

Abstract

In order to improve the practicability of fibrous supercapacitors, stretchability is a significant characteristic for the devices, which puts forward high requirements for electrode materials. In this work, highly stretchable and conductive CNTs/MXene-TPU hybrid fiber electrodes with porous structure were prepared by wet spinning technique. The mechanical and electrical properties of the fiber electrodes remained stable during the tensile process when the amount of CNTs/MXene is 10 wt%. Meanwhile, the electrodes also showed a high volumetric specific capacitance of 3.9 F cm−3 even at the scan rate of 1 V s−1. The all-solid-state fibrous supercapacitors based on CNTs/MXene-TPU fiber electrodes also exhibited superior electrochemical performance and can be stretched by more than 50% strain. The specific capacitance of the devices changed with the tensile strain and reached 3.1 F cm−3 while the stain was 50%. Based on these characteristics, the fibrous supercapacitors were further applied to flexible strain sensors, which can convert action signals to electrochemical signals rapidly. The stretchable fibrous supercapacitor can be used not only for energy storage, but also as a strain sensor to monitor human movements, making it very promising for the next generation smart textiles.