Carbon nanotube network film directly grown on carbon cloth for high-performance solid-state flexible supercapacitors

Carbon nanotubes (CNTs) have received increasing attention as electrode materials for high-performance supercapacitors. We herein present a straightforward method to synthesize CNT films directly on carbon cloths as electrodes for all-solid-state flexible supercapacitors (AFSCs). The as-made highly conductive electrodes possess a three-dimensional (3D) network architecture for fast ion diffusion and good flexibility, leading to an AFSC with a specific capacitance of 106.1 F g(-1), an areal capacitance of 38.75 mF cm(-2), an ultralong cycle life of 100 000 times (capacitance retention: 99%), a good rate capability (can scan at 1000 mV s(-1), at which the capacitance is still similar to 37.8% of that at 5 mV s(-1)), a high energy density (2.4 mu W h cm(-2)) and a high power density (19 mW cm(-2)). Moreover, our AFSC maintains excellent electrochemical attributes even with serious shape deformation (bending, folding, etc), high mechanical pressure (63 kPa) and a wide temperature window (up to 100 degrees C). After charging for only 5 s, three such AFSC devices connected in series can efficiently power a red round LED for 60 s. Our work could pave the way for the design of practical AFSCs, which are expected to be used for various flexible portable/wearable electronic devices in the future.