Superelastic supercapacitors with high performances during stretching

(Figure Presented). A fiber-shaped supercapacitor that can be stretched over 400% is developed by using two aligned carbon nanotube/polyaniline composite sheets as electrodes. A high specific capacitance of approximately 79.4 F g^-1 is well maintained after stretching at a strain of 300% for 5000 cycles or 100.8 F g^-1 after bending for 5000 cycles at a current density of 1 A g^-1. In particular, the high specific capacitance is maintained by 95.8% at a stretching speed as high as 30 mm s^-1.