Scientists at Ohio State University have fused a rechargeable battery with a solar cell, creating the world's first-ever solar battery -- a feat they've detailed in the latest issue of the journal Nature Communications. Researchers say their invention will make solar power use at home more efficient and inexpensive.
"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," lead researcher Yiying Wu, professor of chemistry and biochemistry at Ohio State, explained in a press release. "We've integrated both functions into one device. Any time you can do that, you reduce cost."
The researchers responsible for the new battery were able to solve a number of engineering problems that have previously prevented the construction of a solar cell and battery hybrid. First, the team employed a mesh solar panel, allowing the battery to breathe as the rods of titanium dioxide capture light. A thin sheet of porous carbon and a lithium plate help convert the light into electrons.
Wu and his colleagues also developed a special process for carrying electrons directly from the layered solar panel into the battery. This more efficient transference solves a longstanding problem of electrons being lost en route. Normally, only about 80 percent of electrons make it from the solar cell to the battery, but researchers say the new device ensures almost no electrons go to waste.
Once inside the battery, electrons are converted into energy as they enable the chemical decomposition of lithium peroxide, a process that produces lithium ions and oxygen. The oxygen is released back through the mesh solar panel and into the air, as the lithium ions are stored for use. The reverse happens when it's time to use the stored energy for electricity.
"Basically, it's a breathing battery," Wu said. "It breathes in air when it discharges, and breathes out when it charges."