A team of researchers has come up with a possible solution to the riddle of powering electric cars.
Researchers at Georgia Institute of Technology have created a nanofiber that could help enable the next generation of rechargeable batteries and increase the efficiency of hydrogen production from water electrolysis.
In a study, the researchers describe the development of double perovskite nanofiber that can be used as a highly efficient catalyst in ultrafast oxygen evolution reactions - one of the underlying electrochemical processes in hydrogen-based energy and the newer metal-air batteries.
"Metal-air batteries, such as those that could power electric vehicles in the future, are able to store a lot of energy in a much smaller space than current batteries," said researcher Meilin Liu. "The problem is that the batteries lack a cost-efficient catalyst to improve their efficiency. This new catalyst will improve that process."
Perovskite refers to the crystal structure of the catalyst the researchers used to form the nanofibers.
"This unique crystal structure and the composition are vital to enabling better activity and durability for the application," Liu said.
During the synthetization process, the researchers used a technique called composition tuning - or "co-doping" - to improve the intrinsic activity of the catalyst by approximately 4.7 times. The perovskite oxide fiber made during the electrospinning process was about 20 nanometers in diameter - which thus far is the thinnest diameter reported for electrospun perovskite oxide nanofibers.
The researchers found that the new substance showed markedly enhanced oxygen evolution reaction capability when compared to existing catalysts. The new nanofiber's mass-normalized catalytic activity improved about 72 times greater than the initial powder catalyst, and 2.5 times greater than iridium oxide, which is considered a state of the art catalyst by current standards.
"Solar, wind, geothermal - those are becoming very inexpensive today. But the trouble is those renewable energies are intermittent in nature," Liu noted. "When there is no wind, you have no power. But what if we could store the energy from the sun or the wind when there's an excess supply? We can use that extra electricity to produce hydrogen and store that energy for use when we need it."
"To store that energy, batteries are still very expensive," Liu added. "We need a good catalyst in order for the water electrolysis to be efficient. This catalyst can speed up electrochemical reactions in water splitting or metal air batteries."
