Omnidirectionally Stretchable High-Performance Supercapacitor Based on Isotropic Buckled Carbon Nanotube Films

Abstract

The emergence of stretchable electronic devices has attracted intensive attention. However, most of the existing stretchable electronic devices can generally be stretched only in one specific direction and show limited specific capacitance and energy density. Here, we report a stretchable isotropic buckled carbon nanotube (CNT) film, which is used as electrodes for supercapacitors with low sheet resistance, high omnidirectional stretchability, and electro-mechanical stability under repeated stretching. After acid treatment of the CNT film followed by electrochemical deposition of polyaniline (PANI), the resulting isotropic buckled acid treated CNT@PANI electrode exhibits high specific capacitance of 1147.12 mF cm(-2) at 10 mV s(-1). The supercapacitor possesses high energy density from 31.56 to 50.98 μWh cm(-2) and corresponding power density changing from 2.294 to 28.404 mW cm(-2) at the scan rate from 10 to 200 mV s(-1). Also, the supercapacitor can sustain an omnidirectional strain of 200%, which is twice the maximum strain of biaxially stretchable supercapacitors based on CNT assemblies reported in the literature. Moreover, the capacitive performance is even enhanced to 1160.43-1230.61 mF cm(-2) during uniaxial, biaxial, and omnidirectional elongations.

Orange-Peel-Derived Carbon: Designing Sustainable and High-Performance Supercapacitor Electrodes

“…We compared these values to previously reported supercapacitors based on other forms of carbon (inset Figure 6d). For example, the energy and power performance of polyaniline-deposited CNT (50.98 µWh/cm 2 at 28.404 mW/cm 2 ) [70], a graphene oxide-polypyrrole composite (16.8 µWh/cm 2 at 0.08 mW/cm 2 ) [71], a polypyrrole-MnO 2 -CNT coated cotton thread (33 µWh/cm 2 at 0.67 mW/cm 2 ) [72], CNT-coated carbon microfiber (9.8 µWh/cm 2 at 0.189 mW/cm 2 ) [73], and graphene-cellulose paper (1.5 µWh/cm 2 at 0.01 mW/cm 2 ) [74] were inferior to our work. The high power capability of the OPAC-1 supercapacitor indicates its potential for applications where rapid release of energy is required.…”

Superb electromagnetic wave-absorbing composites based on large-scale graphene and carbon nanotube films

“…CNTs were synthesized and entangled in the hot zone forming a stocking-like aerogel. The CNT aerogel was then blown out continuously from the reactor and collected layer-by-layer by a wheel rotating perpendicularly to the gas flow, which formed macroscopic CNT film (thickness: 2 μm; density: 807 mg/cm 3 ) with randomly oriented CNTs 33 . This CNT film was further densified by spraying ethanol onto it to enhance its mechanical and physical properties.

Figure 8Schematics of CNT film fabrication.

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Recent advances in flexible supercapacitors based on carbon nanotubes and graphene

“…2c-f). [45] The CNT film shows anisotropic elasticity and high endurance towards stretching when stretched in different directions (Fig. 2g).…”

“…Approaches including CVD/floating catalyst CVD [41][42][43][44][45][46][47], vacuum filtration [48][49][50][51][52], interfacial reaction [53,54], and printing [55] have been developed to fabricate CNT films for use in flexible supercapacitor applications.…”