First solar battery in the world
Scientists at Ohio State University (OSU) have made a dye-sensitized solar cell that gathers its power by using air to dissolve and re-form lithium peroxide. The researchers think that the gadget, that immediately merges a battery and a solar cells in one, is able to bring down energy costs by 25%.
“The state of the art is to use a solar panel to capture the light, and then use a cheap battery to store the energy,” explains OSU professor Yiying Wu. “We’ve integrated both functions into one device. Any time you can do that, you reduce cost.”
This new creation works with the help of three electrodes, while the other with four. At the base there is a lithium plate where there is a layer of electrolyte, a thin sheet of porous carbon and then another layer of electrolyte. On top there is a permeable titanium gauze mesh houses a dye-sensitive titanium dioxide photoelectrode, that is similar to blades of grass at the 1 μm scale and makes triiodide ions under illumination. After that, the ions go to the oxygen electrode surface with an iodide “shuttle,” where they oxidize into lithium peroxide.
Electrons in the related battery chemically split the lithium peroxide into lithium ions and oxygen, with the oxygen that goes into the air and lithium ions stored as lithium metal. During the time that battery goes low on power, it gathers the oxygen from the environment and consumes it to re-form lithium peroxide – and that it starts again.
The scientists tested the device with a hematite (rust) photoelectrode in order to substitute the dye-sensitized titanium oxide, and brings the same efficiency and strength that can ensure a similar lifetime as existing rechargeable batteries have. If they can find a material that can provide similar efficiency as this titanium oxide version and work for a number of years, the OSU scientists’ design could mean a lot for the green power world.