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
Navigational view of the brain thanks to powerful X-rays
18.10.2017 | Georgia Institute of Technology
Separating methane and CO2 will become more efficient
18.10.2017 | KU Leuven
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
18.10.2017 | Physics and Astronomy
18.10.2017 | Physics and Astronomy
18.10.2017 | Life Sciences