Scientists at Ohio State University are at a loss as to what to call their new invention. It produces electricity like a solar cell, but it also stores energy like a battery. In an article recently published in Nature Communications, the researchers succeeded in producing the hybrid device that is set to tame solar energy costs.
Currently, solar installations have a panel that contains the cells to convert sunlight into electricity, which is connected to a charger that stores the energy in a battery. In the process of transferring the electric power from the solar cells to the batteries, as much as 20% of the energy is lost.
The new device, on the other hand, transfers electricity from the solar cell directly into the attached battery. Not only does this avoid power losses, it also has the potential to reduce costs by 25% because it uses less materials.
The new contraption combines a titanium gauze mesh solar panel with an air-powered battery that the university earlier developed. The battery takes a cue from Karate Kid – it breathes in to discharge power and breathes out to charge up. A mesh solar panel design was necessary in order to facilitate the flow of air, which would be normally blocked by conventional solar cells made of silicon and other semiconductors.
So what happens when light hits the panel, electrons are released into the battery. In the battery, the electrons decompose lithium peroxide into lithium ions and oxygen. The oxygen escapes into the air while the lithium ions remain in the battery in metal form. When you use the battery, oxygen from the air recombines with the lithium to reform lithium peroxide. The secret to this process is an iodide additive to facilitate transport of electrons between the panel and the battery electrode. To enhance performance, the mesh solar panel is dyed red. After trying out a variety of materials and the dust settled, the team settled on using a dye made of rust.
The US Department of Energy is funding further research to improve the device’s performance with the use of new materials, though not a new name. In the meantime, this new hybrid device will be called the solar battery.