Fig. 2: Characterization of omnidirectional prestretched carbon and its electrochemical performance.

a, b SEM images of 0% and 30% omnidirectional prestretched carbon. c, d Optical photographs of 30% omnidirectional prestretched carbon before and after relaxation. e EDS image of carbon. f Infrared spectra of carbon nanotubes before and after acidification. g, h CV and GCD curves, i Nyquist plot of carbon-based supercapacitor materials.