Researchers from Ohio State University have redesigned a prototype solar battery, so it now achieves 20 percent more energy savings compared to standard lithium iodine batteries. Called an aqueous solar flow battery, it is the combination of a solar cell and battery and uses sunlight for partly charging the device.
Yiying Wu, professor of chemistry and biochemistry at Ohio State, has been working on the design that now uses a solid sheet for the solar panel rather than a titanium mesh sheet. The use of a water-based electrolyte inside the battery allows it to be categorised as an ‘aqueous flow battery’.
“This solar flow battery design can potentially be applied for gridscale solar energy conversion and storage, as well as producing ‘electrolyte fuels’ that might be used to power future electric vehicles,” explains doctoral student Mingzhe Yu.
The researchers have been testing the performance of the aqueous flow battery against a lithium iodine battery to record the results. Each battery was charged and discharged 25 times. Both discharged approximately 3.3 volts, however, the aqueous flow battery needed only 2.9 volts of non-solar charging to produce this result. On the other hand, the typical battery required charging to 3.6 volts.
“The truly important innovation here is that we’ve successfully demonstrated aqueous flow inside our solar battery,” Wu said. This he explains is, “totally compatible with current battery technology, very easy to integrate with existing technology, environmentally friendly and easy to maintain”.
The team’s ultimate goal is to enable the solar cell to boost the battery life past its current 20 percent charging rate and perhaps even reach 100 percent rechargeability from solar power alone. In our energy dependent society, aqueous flow batteries could help provide another source of renewable energy to power grids in the future, one that is much more affordable.