NINA FAYNSHTAYN
Both in design and impact, the high-energy rechargeable lithium-air battery engenders hope for fans of alternative energy sources. According to the U.S. Department of Energy, these batteries can store up to 10 times the amount of energy in today’s lithium batteries, which is equivalent to that of gasoline. In fact, they have a higher theoretical specific density energy than that of conventional batteries, making them far more effective. Thus, they are bringing about the possibility of providing energy for electric vehicles. However, like with all great innovations, skeptics attempt to downgrade their benefits. Some choose to believe that due to the lithium peroxide that forms as a byproduct in lithium-air reactions, the battery cathode erodes quicker, causing efficiency problems. However, according to the U.S. Department of Energy-funded project Argonne International, these batteries display “the ultimate battery chemistry,” and researchers are working collaboratively to avoid the issue of lithium peroxide build-up. In fact, some research has disproved that lithium peroxide acts as an effective issue, as other innovations develop. According to a study published in Nature, an international science journal, lithium superoxide, which is safe in production, is stable enough for the battery to be charged and discharged with low charge potential. This discovery could act as a gateway to further research in developing more uses, such as oxygen storage.
Additionally, the reason the battery can successfully avoid issues, is due to the spacing of the iridium catalyst nanoparticles in the reduced graphene oxide cathode that both improves lithium superoxide production, and limits lithium peroxide production. The favorable lithium superoxide easily dissociates back into lithium and oxygen, improving the safety of units. Additionally, in contrast to potential lithium peroxide production, this dissociation efficiency allows for the enhancement of a closed system lithium-air battery.
How does a lithium-air battery work? Scientists at the Lomonosov Moscow State University are studying electrochemical oxygen reduction that occurs in this battery. In order to comprehend how lithium peroxide could be formed as a byproduct, it is significant to understand the basics. When discharging, the negative electrode dissolves and forms lithium ions, moving towards the positive electrode through the electrolyte layer. Most of the time, atmospheric oxygen enters the cell from the environment and reaches the positive electrode. The interaction between the carbon and electrode with the oxygen causes electrochemical oxygen reduction—a process that results in the production of lithium peroxide, in addition to superoxide anions. After a while, these products are converted into the final product. The scientists concluded that the carbon electrode material is the reason for the issues leading up to lithium peroxide production, and that research should focus on shifting away from the use of carbon; they predict that prototypes may start appearing in the early 2020s.
Overall, the future of the high-energy rechargeable lithium-air battery is exciting, yet uncertain. While it has the potential to improve energy production significantly, there are several challenges that must be resolved before large-scale use. Most people wouldn’t consider the importance of the type of battery individuals use. With a promising future ahead, it’s justified to say that they should.
References
Argonne National Library. (2016, January 26). Breakthrough in lithium-air batteries. Retrieved from TreeHugger website: https://www.treehugger.com/renewable-energy/lithium-air-battery-breakthough-confirmed-energy-density.html
How to to bring lithium-air batteries closer to practice January 31, 2017, Lomonosov Moscow State University Read more at: https://phys.org/news/2017-01-lithium-air-batteries-closer.html#jCp. (n.d.). Retrieved from Phys.org website: https://phys.org/news/2017-01-lithium-air-batteries-closer.html
Imanishi, N., & Yamamota, O. (2014, February). Rechargeable lithium–air batteries: characteristics and prospects. Retrieved from Science Direct website: https://www.sciencedirect.com/science/article/pii/S1369702113004586
Jung, K.-N. (2016). Rechargeable lithium–air batteries: a perspective on the development of oxygen electrodes. Retrieved from Royal Society of Chemistry website: http://pubs.rsc.org/en/content/articlelanding/2016/ta/c6ta04510c#!divAbstract
Lu, J. (2016, January 11). A lithium–oxygen battery based on lithium superoxide. Retrieved from Nature website: https://www.nature.com/articles/nature16484
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