Understanding and controlling the rest potential of carbon nanotube-based supercapacitors for energy density enhancement
Source abstract
Abstract
Abstract We present a novel method for enhancing the energy density of an electrical double layer capacitor (EDLC). Surface modification of single-walled carbon nanotube (SWNT) electrodes significantly affects the rest potential (E0) of EDLCs; acid treatment and polyethyleneimine (PEI) coating of SWNTs shift E0 toward more positive and more negative values, respectively. Adjusting E0 towards the center of the electrolyte stability window can increase the cell voltage and hence the energy density. PEI coating on SWNTs increases the cell voltage from 0.8 V to 1.7 V in tetrabutylammonium perchlorate (TBAP)/tetrahydrofuran (THF) electrolyte, and from 2.5 V to 3.1 V in tetraethylammonium tetrafluoroborate (TEABF4)/3-cyanopropionic acid methyl ester (CPAME), respectively. Moreover, PEI-SWNT EDLCs exhibit excellent cycling stability (92% of capacitance retention over 10000 cycles). We attribute the shift in E0 to a change in the Fermi level of SWNTs owing to the surface charge modification. Injection of electrical charge into PEI-SWNTs consistently yielded similar trends and thus validated our hypothesis. Our results may help to push various electrolytes that have been overlooked so far to new frontiers for obtaining high energy-density supercapacitors.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Supercapacitor Materials and Fabrication · Conducting polymers and applications · Advanced battery technologies research
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (32)
Show source-provided references
1. Conway · 1999
2. Templated mesoporous carbons for supercapacitor application10.1016/j.electacta.2004.11.027 ↗
3. Comparison of commercial supercapacitors and high-power lithium-ion batteries for power-assist applications in hybrid electric vehicles: i. Initial characterization10.1016/S0378-7753(02)00364-6 ↗
4. What are batteries fuel cells, and supercapacitors?10.1021/cr020730k ↗
5. Electrochemical capacitors for energy management10.1126/science.1158736 ↗
6. Materials for electrochemical capacitors10.1038/nmat2297 ↗
7. Carbon-based materials as supercapacitor electrodes10.1039/b813846j ↗
8. A new type of high energy asymmetric capacitor with nanoporous carbon electrodes in aqueous electrolyte10.1016/j.jpowsour.2010.01.006 ↗
9. Towards a further generation of high-energy carbon-based capacitors by using redox-active electrolytes10.1002/anie.201006811 ↗
10. Energy-density enhancement of carbon-nanotube-based supercapacitors with redox couple in organic electrolyte10.1021/am506258s ↗
11. Long-term cycling of carbon-based supercapacitors in aqueous media10.1016/j.electacta.2009.03.024 ↗
12. Strategies to improve the performance of carbon/carbon capacitors in salt aqueous electrolytes10.1149/2.0241505jes ↗
13. A symmetric carbon/carbon supercapacitor operating at 1.6V by using a neutral aqueous solution10.1016/j.elecom.2010.06.036 ↗
14. Asymmetric electrochemical capacitors—Stretching the limits of aqueous electrolytes10.1557/mrs.2011.137 ↗
15. Formulation of ionic-liquid electrolyte to expand the voltage window of supercapacitors10.1002/anie.201412257 ↗
16. Adjustment of electrodes potential window in an asymmetric carbon/MnO2 supercapacitor10.1016/j.jpowsour.2010.06.013 ↗
17. Controlled electrochemical charge injection to maximize the energy density of supercapacitors10.1002/anie.201209259 ↗
18. Adjusting electrode initial potential to obtain high-performance asymmetric supercapacitor based on porous vanadium pentoxide nanotubes and activated carbon nanorods10.1016/j.jpowsour.2015.01.034 ↗
19. Purification of carbon nanotubes grown by thermal CVD10.1016/j.physe.2006.07.014 ↗
20. Electrochemical detection of nanomolar dopamine in the presence of neurophysiological concentration of ascorbic acid and uric acid using charge-coated carbon nanotubes via facile and green preparation10.1016/j.talanta.2015.10.020 ↗
21. Dispersions of surface-modified carbon nanotubes in water-soluble and water-insoluble polymers10.1002/adfm.200500142 ↗
22. Polyethyleneimine-mediated functionalization of multiwalled carbon nanotubes: synthesis, characterization, and in vitro toxicity assay10.1021/jp809323e ↗
23. Modified carbon nanotubes: an effective way to selective attachment of gold nanoparticles10.1016/S0008-6223(03)00339-7 ↗
24. Sensitivity of single-wall carbon nanotubes to chemical processing: an electron microscopy investigation10.1016/S0008-6223(00)00249-9 ↗
25. Modifications of single-wall carbon nanotubes upon oxidative purification treatments10.1088/0957-4484/14/7/301 ↗
26. High-performance supercapacitors based on vertically aligned carbon nanotubes and nonaqueous electrolytes10.1088/0957-4484/23/15/155401 ↗
27. Polymer functionalization for air-stable n-type carbon nanotube field-effect transistors10.1021/ja0169670 ↗
28. High electrical conductivity and n-type thermopower from double-/single-wall carbon nanotubes by manipulating charge interactions between nanotubes and organic/inorganic nanomaterials10.1016/j.carbon.2011.06.082 ↗
29. 25th anniversary article: chemically modified/doped carbon nanotubes & graphene for optimized nanostructures & nanodevices10.1002/adma.201303265 ↗
30. Low-cost transparent, and flexible single-walled carbon nanotube nanocomposite based ion-sensitive field-effect transistors for pH/glucose sensing10.1016/j.bios.2010.03.003 ↗
31. A simple method for the determination of doping type in nanomaterials based on electrical response to humidity10.1063/1.4757609 ↗
32. Effects of vacancy-carboxyl pair functionalization on electronic properties of carbon nanotubes10.1063/1.2364844 ↗