It is easy to capture energy with solar panels, but it is not so easy to store it. It is necessary to have good batteries capable of storing that energy for night use, or for when there are clouds … or for winter. In the case of flow batteries, storage is relegated to liquid reservoirs, and now there is news on that subject.
An international team led by scientists from the University of Wisconsin-Madison has created a new version of these solar flux batteries that is more efficient and durable.
The result has been a mix of existing technologies. It is a silicon / perovskite solar cell, combined with a redox flow battery, which allows energy to be captured and stored in a single device (it will not be necessary to have a solar panel on one side and a battery on the other).
The invention is inexpensive and simple, so that people can use it at home.
Silicon and perovskite capture different wavelengths of light, so combined they increase efficiency. For storage, the equipment used a flow battery. Traditionally, these devices contain two liquids, housed in separate tanks, that function as electrolytes. The electricity from the solar cell charges one of the liquids, where it can remain more or less indefinitely. When energy is needed, the two liquids interact in an intermediate chamber, creating a chemical reaction that produces electricity.
The team used a theoretical modeling method to determine which chemicals would work best to maximize efficiency. They decided on two organic compounds dissolved in salt water, and tests with the final physical device confirmed that it was a good combination.
The equipment registered an efficiency of 20 percent, which is on par with the best, but also in this case it had a life of hundreds of hours and charge and discharge cycles, much longer than other flow batteries.
The research was published in the journal Nature Materials, now it’s time to put the batteries to bring this breakthrough to the market.