An oxide/carbon composite outperforms expensive platinum composites in oxygen chemical reactions for green energy devices
Electrochemical devices are crucial to a green energy revolution in which clean alternatives replace carbon-based fuels. This revolution requires conversion systems that produce hydrogen from water or rechargeable batteries that can store clean energy in cars. Now, Singapore-based researchers have developed improved catalysts as electrodes for efficient and more durable green energy devices1.
Electrochemical devices such as batteries use chemical reactions to create and store energy. One of the cleanest reactions is the conversion from water into oxygen and hydrogen. Using energy from the sun, water can be converted into those two elements, which then store this solar energy in gaseous form. Burning hydrogen leads to a chemical explosion that produces water.
For technical applications, the conversion from hydrogen and oxygen into water is done in fuel cells, while some rechargeable batteries use chemical reactions based on oxygen to store and release energy. A crucial element for both types of devices is the cathode, which is the electrical contact where these reactions take place.
For a well-functioning cathode, the electronic energy levels of the cathode material need to be well matched to the energies required for the oxygen reactions. An ideal material for such reactions is MnCo2O4, a spinel oxide, which has the advantage that its energy states can be fine tuned by adjusting its composition.
The research team, which included Zhaolin Liu and colleagues from the A*STAR Institute of Materials Research and Engineering with colleagues from Nanyang Technological University and the National University of Singapore, combined nanometer-sized crystals of this material with sheets of carbon or carbon nanotubes.
These composites offer several benefits including low cost and high efficiency. “The cost is estimated to be tens of times cheaper than the platinum/carbon composites used at present,” says Liu. Because platinum is expensive, intensive efforts are being made to find alternative materials for batteries.
The researchers fabricated these composites using a scalable chemical synthesis method and studied their performance in oxygen reactions. In these tests, the composites clearly outperformed the platinum-based alternatives. They were more efficient than the platinum-based solutions, with comparable devices in the lab lasting about five times longer, for more than 64 charge-discharge cycles.
While these are still research laboratory results, the first results for full battery prototypes are encouraging, comments Liu. “We envisage a 100-watt rechargeable battery stack in one to two years and a 500-watt one in one to three years.”
The A*STAR-affiliated researchers contributing to this research are from the Institute of Materials Research and Engineering.
Ge, X., Liu, Y, Goh, F. W. T., Hor, T. S. A., Zong, Y. et al. Dual-phase spinel MnCo2O4 and spinel MnCo2O4/nanocarbon hybrids for electrocatalytic oxygen reduction and evolution. ACS Applied Materials & Interfaces 6, 12684−12691 (2014). | article
Further reports about: > A*STAR > Applied Materials > Electrochemical > Energy > Engineering > carbon nanotubes > chemical reactions > chemical synthesis > electronic energy > energy levels > green energy > rechargeable batteries > rechargeable battery > solar energy > store energy > synthesis method > technical applications
Microscope measures muscle weakness
16.11.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg
Good preparation is half the digestion
16.11.2018 | Max-Planck-Institut für Stoffwechselforschung
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
16.11.2018 | Health and Medicine
16.11.2018 | Life Sciences
16.11.2018 | Life Sciences