Fig. 2

Fabrication and properties of the stretchable supercapacitor devices. a Schematic for fabrication of a stretchable supercapacitor by using the hydrogel as electrolyte and CNT films as electrodes through a pre-strain/release process. b–d Scanning electron microscopy (SEM) images of the formed wrinkled CNTs (b, scale bar: 200 μm) in a supercapacitor being re-stretched to strains of 900% (c, scale bar: 500 nm) and 1000% (d, scale bar: 500 nm). e–g Cyclic voltammetry (CV) curves (e), galvanostatic charge/discharge (GCD) curves (f) and normalized electrochemical performance (g) of a supercapacitor being stretched from 0 to 1000% strain. h Comparison of capacitance retention and stretchability of our stretchable supercapacitors with other results reported previously