fig3

Figure 3. (A) CV and (B) GCD curves of HPFs tested at different potential windows from 0.0 to 1.2-1.8 V. (C) CV curves of HPFs at different scan rates. (D) GCD curves of HPFs at different current densities and (E) rate capabilities of HPFs and SPFs. (F) Ragone plots of HPFs compared with SPFs and other reported results. CV curves of one, two and three devices connected (G) in parallel and (H) in series at a scan rate of 20 mV s^-1. (I) Cycling performance of FSCs based on HPFs measured at a current density of 2 mA cm^-2. CV: Cyclic voltammetry; GCD: galvanostatic charge-discharge; HPF: hollow poly(3,4-ethylenedioxythiophene):polystyrene sulfonate thin-walled fibers; FSC: fiber-shaped supercapacitor; SPF: solid PEDOT:PSS fibers.