Highly deformation-tolerant carbon nanotube sponges as supercapacitor electrodes

Abstract

Developing flexible and deformable supercapacitor electrodes based on porous materials is of high interest in energy related fields. Here, we show that carbon nanotube sponges, consisting of highly porous conductive networks, can serve as compressible and deformation-tolerant supercapacitor electrodes in aqueous or organic electrolytes. In aqueous electrolytes, the sponges maintain a similar specific capacitance (>90% of the original value) under a predefined compressive strain of 50% (corresponding to a volume reduction of 50%), and retain more than 70% of the original capacitance under 80% strain while the volume normalized capacitance increases by 3-fold. The sponge electrode maintains a stable performance after 1000 large strain compression cycles. A coin-shaped cell assembled with these sponges shows excellent stability over 15,000 charging cycles with negligible degradation after 500 cycles. Our results indicate that carbon nanotube sponges have the potential to fabricate deformable supercapacitor electrodes with stable performance.

Three-dimensional α-Fe2O3/carbon nanotube sponges as flexible supercapacitor electrodes

“…39,40 The specific capacitance calculated from the CV curves (Fig. 28 Two small redox peaks were also observed at -0.5V. Cycling stability of the CNT@Fe 2 O 3 electrode was investigated at a scan rate of 100 mV/s for 1000 cycles (Fig.…”

Programmable Nanocarbon‐Based Architectures for Flexible Supercapacitors

“…CNT sponges with appropriate thickness synthesized by CVD can also be compressed into thin fi lms by a mechanical instrument or hydraulic punching to act as fl exible SC electrodes. [ 64 ] Because CNT arrays and sponges often grow on the surface of infl exible substrates, they have to be transferred to fl exible substrate to serve as SC electrode. Furthermore, as with directly grown CNT fi lms, the preparation of CNT arrays and sponges is also diffi cult to scale up.…”

Materials and fabrication of electrode scaffolds for deposition of MnO2 and their true performance in supercapacitors

“…However, for electrode scaffolds with ultraporous structures thus very small packing densities, like CNTs sponge (10e20 mg cm À3 ) [80], graphene aerogel (0.16 mg cm À3 ) [81], are hardly to be able to achieve high volumetric capacitance due to the large portion of dead volume (excess pore volume) in the electrodes. For instance, the CNT-PPy-MnO 2 nanotube sponge could only give a small volumetric capacitance of 16.1 F cm À3 even with 50% compression [82].…”