One of the things you hear a lot about when discussing the future of clean technology is that renewable energy can't be rolled out on a massive scale without reliable energy storage being installed along with it. Many researchers are working on grid-scale batteries and other energy storage technologies, but what if a technology could both generate clean energy and store it simultaneously?
Claiming to have achieved just that, Ohio State University researchers have developed a solar battery that operates both as a solar cell and energy storage device and could potentially cut renewable energy costs by 25 percent.
“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,” said OSU professor Yiying Wu. “We’ve integrated both functions into one device. Any time you can do that, you reduce cost.”
The key to the device is a dye-sensitized mesh solar panel that allows both light and air in. The battery basically breathes, it takes in air when it discharges and releases it when it charges.
The device consists of the mesh solar panel, which acts as the first electrode, beneath that is a thin sheet of porous carbon that is the second electrode and a lithium plate that is the third electrode. Between the electrodes are sandwiched layers of electrolyte for carrying electrons back and forth.
According to OSU, it works like this: "during charging, light hits the mesh solar panel and creates electrons. Inside the battery, electrons are involved in the chemical decomposition of lithium peroxide into lithium ions and oxygen. The oxygen is released into the air, and the lithium ions are stored in the battery as lithium metal after capturing the electrons. When the battery discharges, it chemically consumes oxygen from the air to re-form the lithium peroxide."
This technology solves a major problem in the storage of renewable energy. Typically, transferring energy generated by a solar panel to an external battery results in a 20 percent loss of electricity. Since light is converted to electrons in the battery, there is virtually no electricity loss, allowing almost 100 percent to be stored.
After testing the researchers concluded that the lifetime of the battery will be similar to rechargeable batteries already on the market.