Category Physics

Schematic of a “solar flow battery” with the three-electrode configuration: lithium anode electrode, counter electrode (CE), and photo-electrode (PE). Current passes through a liquid in the battery called an electrolyte. The portion of the electrolyte near the cathode electrode is called a “catholyte.” The CE and PE electrodes are in contact with the “catholyte.” Credit: Image courtesy of Yiying Wu, The Ohio State University

More efficient, eco-friendly electricity generation with a “solar flow battery” combines a redox flow battery and a dye-sensitized solar cell, using compatible, water-based (aqueous) solvents. Solar energy is harvested and stored as chemical energy during the charging process. When it is time to recharge the battery, the amount of energy needed to is lower than conventional lithium-iodine batteries because dye molecules, exposed to the sun, donate electrons to the recharging process.

Energy generation from a solar flow battery is more cost-effective, eco-friendly, and can achieve energy savings up to 20% compared to conventional lithium-iodine batteries. Solar flow batteries make renewable solar energy more practical for keeping the lights on and appliances running with stand-alone electricity generation and storage.

Last year, researchers at The Ohio State University demonstrated photo-assisted charging of a lithium-oxygen (Li-O2) battery; however, they used organic (carbon-based) solvents that limited its compatibility with aqueous redox flow batteries. Now, these researchers have built a solar flow battery that uses an eco-friendly, compatible solvent and requires a lower applied voltage to recharge the battery. In solar flow batteries, the proposed charging process links harvesting solar energy and storing it as chemical energy via the electrolyte.

The aqueous electrolyte is in contact with the counter electrode of the battery and the dye-sensitized photo-electrode of the solar cell. To recharge the battery, it is exposed to sunlight. The sunlight causes the dye molecules in the electrolyte to donate electrons to the photo-electrode, reducing the amount of energy needed to recharge the battery. The applied voltage to recharge the solar flow battery is reduced to 2.9 Volts compared to > 3.6 Volts for conventional lithium-iodine batteries, resulting in an energy savings of up to 20%.

The aqueous solar flow battery performs better and is more cost-effective and eco-friendly than those based on organic solvents. The aqueous solar flow battery could solve the intermittency shortcomings of renewable energy and keep the lights on and appliances running. http://science.energy.gov/bes/highlights/2015/bes-2015-10-f/

“Outflows” (red), regions where plumes of hot gas escape the intense nuclear burning at a star’s surface, form at the onset of convection in the helium shell of some white dwarf stars. This visualization depicts early convection on the surface of white dwarf stars of different masses. Credit: Adam Jacobs, Stony Brook University

3D simulations of double-detonation Type Ia supernovas reveal dynamic burning. Exploding stars may seem like an unlikely yardstick for measuring the vast distances of space, but astronomers have been mapping the universe for decades using stellar eruptions, supernovas, with surprising accuracy.

Type Ia supernovas – exploding white dwarf stars -are considered the most reliable distance markers for objects beyond our local group of galaxies...

Illustration depicting biocell attached to CMOS integrated circuit with membrane containing sodium-potassium pumps in pore. Credit: Trevor Finney and Jared Roseman/Columbia Engineering

System combines biological ion channels with solid-state transistors to create a new kind of electronics. Researchers have, for the first time, harnessed the molecular machinery of living systems to power an integrated circuit from ATP, energy currency of life. They integrated a conventional solid-state complementary metal-oxide-semiconductor (CMOS) integrated circuit with an artificial lipid bilayer membrane with ATP-powered ion pumps, opening the door to creating entirely new artificial systems that contain both biological and solid-state components.

“We are excited at the prospect of expanding the palette...

Physicists at Penn State University have for the 1st time proposed a way to test a little-understood form of quantum mechanics called nonassociative quantum mechanics. So far, all other tests of quantum mechanics have dealt with the associative form. “Nonassociative quantum mechanics has been of mathematical interest for some time (and has recently shown up in certain models of String Theory), but it has been impossible to obtain a physical understanding,” said Martin Bojowald. “We have developed methods which allow us to do just that, and found a first application with a characteristic and instructive result. One of the features that makes this setting interesting is that much of the usual mathematical toolkit of quantum mechanics is inapplicable.”

Standard quantum mechanics is cons...