All-nanotube stretchable supercapacitor with low equivalent series resistance

Evgenia P Gilshteyn,Daler Amanbayev,Tanja Kallio,Anton S Anisimov,Albert G Nasibulin

doi:10.1038/s41598-017-17801-4

Evgenia P Gilshteyn, Daler Amanbayev + Show 3 more

Open Access

https://doi.org/10.1038/s41598-017-17801-4

Copy DOI

Abstract

We report high-performance, stable, low equivalent series resistance all-nanotube stretchable supercapacitor based on single-walled carbon nanotube film electrodes and a boron nitride nanotube separator. A layer of boron nitride nanotubes, fabricated by airbrushing from isopropanol dispersion, allows avoiding problem of high internal resistance and short-circuiting of supercapacitors. The device, fabricated in a two-electrode test cell configuration, demonstrates electrochemical double layer capacitance mechanism and retains 96% of its initial capacitance after 20 000 electrochemical charging/discharging cycles with the specific capacitance value of 82 F g−1 and low equivalent series resistance of 4.6 Ω. The stretchable supercapacitor prototype withstands at least 1000 cycles of 50% strain with a slight increase in the volumetric capacitance from 0.4 to 0.5 mF cm−3 and volumetric power density from 32 mW cm−3 to 40 mW cm−3 after stretching, which is higher than reported before. Moreover, a low resistance of 250 Ω for the as-fabricated stretchable prototype was obtained, which slightly decreased with the strain applied up to 200 Ω. Simple fabrication process of such devices can be easily extended making the all-nanotube stretchable supercapacitors, presented here, promising elements in future wearable devices.

Highlights

Research in the domain of flexible and stretchable supercapacitors is focused on adjusting electrodes, as they affect the performance the most[1,2,3]
Uniform structure of the aerosol synthesized single-walled carbon nanotubes (SWCNTs) film could be confirmed based on SEM microscopy (Fig. 3A)
Due to the entangled structure, the SWCNT films can be stretched without noticeable changes in electrical conductivity and they possess high specific surface area[29], that makes them ideal for the electric double-layer capacitor (EDLC) electrode

Summary

Results and Discussion

Uniform structure of the aerosol synthesized SWCNT film could be confirmed based on SEM microscopy (Fig. 3A). It is noteworthy that the changes in the low-frequency region line in the impedance spectra suggest improved ion transfer with the stretching Another important finding is that the ESR value of the all-nanotube SSC prototype was two orders of magnitude lower compared to the stretchable supercapacitors with PVA/H2SO4 separator of the similar stretchable configuration (ESR = 15 kΩ). The SSC device was stretched up to 50% strain without any significant change in the electrochemical performance

Stretchable prototype with BNNT separator

Conclusions

Author Contributions

Additional Information