These micro-supercapacitors have the potential to power nomad electronics, wireless sensor networks, biomedical implants, active radiofrequency identification (RFID) tags and embedded microsensors, among other devices.
Supercapacitors, also called electric double layer capacitors (EDLCs) or ultracapacitors, bridge the gap between batteries, which offer high energy densities but are slow, and “conventional” electrolytic capacitors, which are fast but have low energy densities.
The newly developed devices described in Nature Nanotechnology have powers per volume that are comparable to electrolytic capacitors, capacitances that are four orders of magnitude higher, and energies per volume that are an order of magnitude higher. They were also found to be three orders of magnitude faster than conventional supercapacitors, which are used in backup power supplies, wind power generators and other machinery. These new devices have been dubbed “micro-supercapacitors” because they are only a few micrometers (0.000001 meters) thick.
What makes this possible? “Supercapacitors store energy in layers of ions at high surface area electrodes,” said Dr. Yury Gogotsi, Trustee Chair Professor of materials science and engineering at Drexel University, and a co-author of the paper. “The higher the surface area per volume of the electrode material, the better the performance of the supercapacitor.”
Dr. Vadym Mochalin, research assistant professor of materials science and engineering at Drexel and co-author, said, “We use electrodes made of onion-like carbon, a material in which each individual particle is made up of concentric spheres of carbon atoms, similar to the layers of an onion. Each particle is 6-7 nanometers in diameter.”
This is the first time a material with very small spherical particles has been studied for this purpose. Previously investigated materials include activated carbon, nanotubes, and carbide-derived carbon (CDC).
“The surface of the onion-like carbons is fully accessible to ions, whereas with some other materials, the size or shape of the pores or of the particles themselves would slow down the charging or discharging process,” Mochalin said. “Furthermore, we used a process to assemble the devices that did not require a polymer binder material to hold the electrodes together, which further improved the electrode conductivity and the charge/discharge rate. Therefore, our supercapacitors can deliver power in milliseconds, much faster than any battery or supercapacitor used today.”
The Drexel team of Gogotsi and Mochalin collaborated with Dr. David Pech, Dr. Magali Brunet, Hugo Durou, Peihua Huang, Dr. Pierre-Louis Taberna, and professor Patrice Simon, all working in Toulouse, France, on the Nature Nanotechnology paper. A grant from the Partner University Fund of the French-American Cultural Exchange allowed two of the Toulouse-based researchers, Pech and Huang, to spend a month each visiting Professor Gogotsi’s laboratory at Drexel University in Philadelphia. Additional exchange visits are planned for the 2010-2011 academic year. The effort at Drexel University is based upon work supported as part of the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under award no. ERKCC61.
Niki Gianakaris | Newswise Science News
How protons move through a fuel cell
22.06.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt
Fraunhofer IZFP acquires lucrative EU project for increasing nuclear power plant safety
21.06.2017 | Fraunhofer-Institut für Zerstörungsfreie Prüfverfahren IZFP
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Agricultural and Forestry Science
26.06.2017 | Life Sciences
26.06.2017 | Health and Medicine