Figure 4. Performance and demonstration of supercapacitor devices.

(a) Normalized capacitance as a number of wrapping of CNC film (0 to 720°). (b) Normalized capacitance as a function of cycle-number (10,000) and w/wo the mechanical deformation (45° bending). (c, d) Optical pictures demonstrating optical transparency and mechanical flexibility of a large scale CNC supercapacitor films. Note that a LED is turned on and remain stable even after helically wrapped into the differently sized glass tubes. The large area CNC supercapacitor film (3 cm by 1.5 cm) over the smartphone screen demonstrates optical transparency and the CNC capacitor films (3 cm by 1.5 cm and 3.5 cm by 0.5 cm) helically wrapped around two differently sized glass tubes (1.6 cm and 0.5 cm diameter) show excellent performance during power delivery.