Scientists have combined a solar cell and a battery into a single device that achieves a 20 percent energy boost compared to traditional lithium-iodine batteries.
The extra energy comes from Sun captured by the solar cell situated on top of the battery, The Ohio State University reported.
The research team had debuted the world's first solar air battery last fall, but this new design is considered to be a milestone in these types of devices. The new model uses a solar panel made from a solid sheet instead of the mesh seen in the previous design. The battery now contains a water-based electrolyte, making it part of an emerging class of devices called aqueous flow batteries. Researchers have dubbed this recent invention the world's first "aqueous solar flow battery."
"The truly important innovation here is that we've successfully demonstrated aqueous flow inside our solar battery," said Yiying Wu, professor of chemistry and biochemistry at Ohio State. "It's also totally compatible with current battery technology, very easy to integrate with existing technology, environmentally friendly and easy to maintain."
Aqueous flow batteries could potentially be used to provide affordable power grid-level energy storage, and the aqueous solar flow battery could help "bridge the gap" between the energy grid and renewable energy.
"This solar flow battery design can potentially be applied for grid-scale solar energy conversion and storage, as well as producing 'electrolyte fuels' that might be used to power future electric vehicles," said Mingzhe Yu, lead author of the paper and a doctoral student at Ohio State.
The researchers compared the solar flow battery's performance to that of a typical lithium-iodine battery by charging and discharging them 25 times. They observed both batteries discharged about 3.3 volts, but the solar flow battery could produce the same output with less charging. In the future, the researchers hope to determine a way to boost the solar panel's contribution to the battery's energy to as much as 100 percent.
"That's our next step," Wu said, "to really achieve a fully solar-chargeable battery."
The breakthrough was published in a recent edition of the Journal of the American Chemical Society, and was funded by the Department of Energy.
