Lithium-air batteries sound too good to be true-using the oxygen available in the air to produce electricity. Theoretically, they could become serious competitors to lithium-ion batteries; but so far, a commercial reality hasn't emerged.
Now, a team of researchers from the University of Illinois and the Argonne National Laboratory have announced what could be a real breakthrough if their results can be replicated with identical performance of the battery.
First, how do lithium-air batteries work? They use oxygen from the air to combine it with lithium in the anode and produce lithium peroxide. This is what happens during the discharge phase. During the charge phase, the lithium peroxide gets broken down back into lithium and oxygen.
As simple as this sounds, there are several major challenges with the process.
Lithium peroxide, for one, is a bad electron conductor, which compromises the battery's effectiveness. What's more, deposits of it build up on the cathode, which eventually stops the chemical reaction producing electricity. On top of that, if you use oxygen from the natural air (which is the ultimate idea) you get other chemicals with it, notably carbon dioxide. When the lithium ions combine with the carbon dioxide and water vapors, they also build up on the cathode, again eventually leading to the end of the chemical reaction.
According to one of the authors of this new study, researchers have found a way around these problems by coating the anode with lithium carbonate and the cathode with a special catalyst made form molybdenum disulfate. They also made an all-new electrolyte that facilitates the reaction between lithium and oxygen, while minimizing the interaction of lithium with other chemicals.
The team claims their battery still worked after 750 charge/discharge cycles, which is probably a first for a lithium-air battery.
However, it's too early to rejoice. Three years ago University of Cambridge researchers announced a battery breakthrough, claiming they had made a lithium-air cell that could make electric cars much cheaper while extending their range. Related: Why Natural Gas Prices Will Rise This Summer
Just a few months later, a number of other scientists disputed the findings of their Cambridge colleagues, arguing the results of their experiments could not be replicated and that the research itself contained errors. Since then, nothing has been heard about that battery.
In case you're wondering why so much effort is being put into making lithium-air batteries a reality, here's the simple answer: they would be much cheaper. This is the same answer you would get for any other battery project. Everyone is in a race to find cheaper batteries that could compete with the lithium-ion technology and make EVs more affordable to facilitate their spread.
Batteries are fast turning into the Holy Grail of the EV industry, just as energy storage is the Holy Grail of renewable power generation. The latter has one over EVs, though. There are already a variety of energy storage solutions that are relatively affordable and their effect on solar and wind power adoption is becoming evident. That should be all the more reason for the battery race to intensify and come up-sooner rather than later-with a viable rival for the lithium-ion battery.
By Irina Slav for Oilprice.com
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Irina is a writer for Oilprice.com with over a decade of experience writing on the oil and gas industry. More
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