Researchers from Korea’s Ulsan National Institute of Science and Technology and the University of Pennsylvania in the US produced a new catalyst that could boost the performance of metal-air batteries, known as MABs.
These batteries use oxygen from ambient air to store and convert energy. In general, they have large storage capacity and are affordable and lightweight, qualities that have sparked the attention of electric vehicle manufacturers.
The batteries are equipped with anodes made up of metals such as lithium, zinc, magnesium and aluminium, and an air cathode that is connected to an inexhaustible source of air. At present, this air cathode is built using platinum, which is rare and expensive.
In the scientists’ view, the use of the precious metal has hindered the massification of MABs. This is why they decided to propose an alternative, using perovskite catalysts that exhibit excellent catalytic performance. The only issue is that these catalysts have low activation barriers.
To counteract such an obstacle, the researchers created a new composite catalyst combining two types of catalysts. A metal catalyst (cobalt oxide), which performs well in charging, is deposited on a very thin layer on top of a manganese-based perovskite catalyst (LSM), which performs well in discharge.
“The synergistic effect of the two catalysts became optimal when the deposition process was repeated 20 times,” the experts said in a media statement.
In other words, the interface naturally formed between the two catalysts enhances the overall performance and stability of the new catalyst and, thus, MABs charge-discharge capabilities.
“Our findings provide the rationale design strategy of self-reconstructed interlayer for efficient electro-catalysts,” Guntae Kim, senior author of the research, said. “Therefore, this work can provide insight into the rational design strategy of metal oxide with perovskite materials.”