But there has been a lack of understanding of what kinds of electrode materials could promote the electrochemical reactions that take place in these batteries.
Lithium-oxygen (also known as lithium-air) batteries are similar in principle to the lithium-ion batteries. But because lithium-air batteries replace the heavy conventional compounds in such batteries with a carbon-based air electrode and flow of air, the batteries themselves can be much lighter.
The researchers in the new study showed that electrodes with gold or platinum as a catalyst show a much higher level of activity and thus a higher efficiency than simple carbon electrodes in these batteries.
In addition, this new work sets the stage for further research that could lead to even better electrode materials, perhaps alloys of gold and platinum or other metals, or metallic oxides, and to less expensive alternatives.
Doctoral student Yi-Chun Lu, lead author of the paper, explains that this team has developed a method for analyzing the activity of different catalysts in the batteries, and now they can build on this research to study a variety of possible materials.
“We’ll look at different materials, and look at the trends. Such research could allow us to identify the physical parameters that govern the catalyst activity. Ultimately, we will be able to predict the catalyst behaviours,” she said.
Lightweight batteries that can deliver lots of energy are crucial for a variety of applications — for example, improving the range of electric vehicles.
Thus, even modest increases in a battery’s energy density rating — a measure of the amount of energy that can be delivered for a given weight — are important advances.
The study has been published in the journal Electrochemical and Solid-State Letters.