Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Power Grid Buffer?

06.06.2011
New production process for NiO/Ni nanocomposite electrodes for supercapacitors
Angewandte Chemie celebrates the 50th anniversary of its International Edition with symposia in Tokyo and Beijing on June 20 and 22. Several Nobel laureates participate in the events, which will be transmitted over the internet. Learn more and join the excitement at angewandte.org/symposium.

Conversion to renewable energy sources like wind and sun is only a question of time. Because wind and solar radiation vary in strength, the increase in renewable energy sources will cause significant fluctuations in the power grid. These must be absorbed by energy storage systems. This need could be fulfilled by a device known as a supercapacitor. John Q. Xiao and his team at the University of Delaware (Newark, USA) have now developed a new process for the production of electrodes made of nickel oxide/nickel nanocomposites for electrochemical supercapacitors. As the researchers report in the journal Angewandte Chemie, their process is simple and cost-effective, and could be scaled up for industry.

Supercapacitors combine the advantages of conventional capacitors and batteries: Like a capacitor, they can rapidly deliver high current densities on demand; like a battery, they can store a large amount of electrical energy. Supercapacitors consist of electrochemical double-layers on electrodes when they are wetted with an electrolyte. When a voltage is applied, ions of opposite polarity collect at both electrodes, forming whisper-thin zones of immobile charge carriers.

The problem is that most processes for the production of the required nanostructured electrodes are either too sensitive to work at an industrial scale or require the addition of substances that later interfere with the electrodes’ function. Sometimes the electrical resistance of the materials is too high. Xiao’s team has now developed a new process for the production of electrodes from a nickel oxide/nickel nanocomposite that can overcome these obstacles.

The scientists first produce nickel nanoparticles. High-boiling polyalcohols, known as polyols, serve as the reaction medium. These cover the growth surfaces of the seed crystals, forming small spherical particles. The nanoparticles are then pressed together into pellets and deposited onto one side of a very thin platinum sheet, which later acts as the current collector. Annealing at 250 °C forms a layer of nickel oxide (NiO) around the pellet, which is the actual active layer of the supercapacitor. This results in compact, stable, highly porous Ni/NiO electrodes that do not require a support. Potassium hydroxide serves as the electrolyte.

During the charging process, OH– ions are bound to the NiO, giving off electrons. The process is reversed when the stored electrical energy is drawn off as current. Its high granularity gives the material a large inner surface area, providing good diffusion pathways for the ions. At the same time, the conductive network of the metal particles is maintained, which is important for high electrical conductivity. These characteristics are the reason for the surprisingly high capacity of the electrodes as well as their high power density and current density during the charge/discharge cycles.

Author: John Q. Xiao, University of Delaware, Newark (USA), http://www.physics.udel.edu/~jqx/
Title: Supercapacitor Electrodes with High-Energy and Power Densities Prepared from Monolithic NiO/Ni Nanocomposites

Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201101083

John Q. Xiao | Angewandte Chemie
Further information:
http://pressroom.angewandte.org
http://www.physics.udel.edu/~jqx/
http://dx.doi.org/10.1002/anie.201101083

More articles from Life Sciences:

nachricht Ambush in a petri dish
24.11.2017 | Friedrich-Schiller-Universität Jena

nachricht Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

IceCube experiment finds Earth can block high-energy particles from nuclear reactions

24.11.2017 | Physics and Astronomy

A 'half-hearted' solution to one-sided heart failure

24.11.2017 | Health and Medicine

Heidelberg Researchers Study Unique Underwater Stalactites

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>