Fig. 4.

Structure and electrochemical performances of rGO/SWCNT hybrid-film-based flexible tape SCs. a A folded rGO/SWCNT hybrid film. b Cross-sectional SEM image of a rGO/SWCNT film. Scale bar: 1 μm. c Continuous long rGO/SWCNT hybrid ribbon obtained by cutting a film. d Tape SC made by the ribbon in c. e Galvanostatic charge/discharge curves measured between 0 and 1 V at current density from 114 to 1894 mA cm⁻³, and the electrode and device volumetric capacitance as a function of current density. f Cycle life of the tape SC. CV curves after 10, 2000, 4000, 6000, 8000, and 10,000 cycles between 0 and 1 V at 100 mV s^–1, and the volumetric capacitance retention as a function of cycle number. g Volumetric and gravimetric capacitance comparison of rGO/SWCNT-1 hybrid film and the reported electrode materials. h Volumetric energy and power densities of our tape SC (red stars) compared with the reported all-solid-state SCs with different electrode materials (solid squares) and commercially available state-of-the-art energy storage systems (open squares). i CV curves collected at a scan rate of 50 mV s^–1 and the capacitance as a function of bending angle. j Capacitance retention under both flat and 180° bent states after 1000 cycles. Inset: a digital photograph showing the flexibility of the device