One of the keys to building electric cars that can travel longer distances, or powering more homes with renewable energy, is developing efficient and highly-capable energy storage systems.
Materials 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, published Feb. 27 in Nature Communications and sponsored by the National Science Foundation, 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 Meilin Liu, a Regents Professor in the Georgia Tech School of Materials Science and Engineering. “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.
According to researchers, the unique crystal structure and the composition are vital to enabling better activity and durability for the application.
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 is the thinnest diameter reported for electrospun perovskite oxide nanofibers thus far.
The researchers found that the new substance showed markedly enhanced oxygen evolution reaction (OER) 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.
That increase in catalytic activity comes in part from the larger surface area achieved with nanofibers, the researchers said. Synthesizing the perovskite structure into a nanofiber also boosted its intrinsic activity, which improved how efficiently it worked as a catalyst for OER.
Beyond its applicability in the development of rechargeable metal air batteries, the new catalyst could also represent the next step in creating more efficient fuel cell technologies that could aid in the creation of renewable energy systems.