Posts Tagged ‘battery

Water-based nuclear battery can be used to generate electrical energy

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Long-lasting batteries could be used for emergency equipment and in spaceflight

Structure and mechanism of the plasmon-assisted radiolytic water splitter

Structure and mechanism of the plasmon-assisted radiolytic water splitter

COLUMBIA, Mo. – From cell phones to cars and flashlights, batteries play an important role in everyday life. Scientists and technology companies constantly are seeking ways to improve battery life and efficiency. Now, for the first time using a water-based solution, researchers at the University of Missouri have created a long-lasting and more efficient nuclear battery that could be used for many applications such as a reliable energy source in automobiles and also in complicated applications such as space flight.

“Betavoltaics, a battery technology that generates power from radiation, has been studied as an energy source since the 1950s,” said Jae W. Kwon, an associate professor of electrical and computer engineering and nuclear engineering in the College of Engineering at MU. “Controlled nuclear technologies are not inherently dangerous. We already have many commercial uses of nuclear technologies in our lives including fire detectors in bedrooms and emergency exit signs in buildings.”

The battery uses a radioactive isotope called strontium-90 that boosts electrochemcial energy in a water-based solution. A nanostructured titanium dioxide electrode (the common element found in sunscreens and UV blockers) with a platinum coating collects and effectively converts energy into electrons.

“Water acts as a buffer and surface plasmons created in the device turned out to be very useful in increasing its efficiency,” Kwon said. “The ionic solution is not easily frozen at very low temperatures and could work in a wide variety of applications including car batteries and, if packaged properly, perhaps spacecraft.”

The research, “Plasmon-assisted radiolytic energy conversion in aqueous solutions,” was conducted by Kwon’s research group at MU, and was published in Nature.

Written by physicsgg

September 18, 2014 at 5:13 pm


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Tiny battery is also a nanomotor

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(Top left) A scanning electron microscope image of a copper-platinum nanobattery-based nanomotor. (Top right) A scanning electron microscope image of an asymmetric copper nanorod. (Bottom) Motion diagrams for each device in bromine solution.

Measuring just 3.6 micrometers long, one of the smallest batteries ever made won’t be powering our electronic devices anytime soon, but it does serve as a self-powered nanomotor that is surprisingly fast and efficient. Ultimately, the nanobattery-based motor could be used as a nanomachine and to transport cargo for biomedical applications.
The researchers, Dr. Ran Liu and Prof. Ayusman Sen from the Department of Chemistry at The Pennsylvania State University, have published their study on the nanobattery-based motor in a recent issue of the Journal of the American Chemical Society ASAP.
The nanobattery consists of a single nanowire with a 3-micrometer-long copper end and a 600-nanometer-long platinum end. When the nanobattery is placed in a diluted solution of oxidant (such as bromine or iodine), the copper end serves as the anode and is oxidized while the platinum end functions as the cathode. As the nanobattery discharges itself in the solution, the electrophoresis phenomenon kicks in, so that the electric field generated by the battery’s redox reactions causes the battery to move.
Copper-platinum nanomotors move in an iodine solution (magnified 100x). The copper end of each nanomotor leads, while the brighter platinum end follows. Movement continues until the copper segments are completely converted to copper iodide by the iodine.

The scientific core of this finding is that a short-circuited nanobattery (e.g., copper-platinum segmented nanorod) can be moved by self-electrophoresis resulting from oxidation and reduction occurring, respectively, at the two metals,” Liu told “The generated current can be directly converted to mechanical force.”
This self-electrophoresis phenomenon propels the device to speeds of more than 10 microns (three times its length) per second. That’s the rough equivalent of a 5-meter (16-foot) motorboat moving at 54 kilometers per hour (33.5 miles per hour) through water.
“In this case, the direction of the nanomotor’s movement is random at long time scales,” Liu said. “It can be potentially controlled. For example, if we incorporate a magnetic metal segment in the nanobattery, we can control its moving direction by magnetic field.”
The nanomotor operates continuously until the copper segment is completely oxidized by the bromine or converted to copper iodide by the iodine. Its lifetime, therefore, depends on both the length of the copper segment and the concentration of the oxidant. In their experiments, the researchers observed nanobattery lifetimes of between 40 seconds and 1 minute by changing these variables. (The length of the copper segment can be controlled by its electrodeposition time during fabrication.) The researchers found that the nanomotor’s velocity also depends on the length of the copper segment, where a shorter copper segment gives a higher speed but decreased lifetime…….
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Written by physicsgg

October 19, 2011 at 1:39 pm


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