by Chad Redman
Energy storage technology is a fascinating field of research, boasting numerous potential replacements for the current cutting edge of battery technology – lithium-ion chemistry. One promising and widely researched alternative to lithium-ion batteries is the lithium-air battery. Lithium-air battery technology became widely known to researchers in the field in 2009, and has been the subject of over 300 research papers since 2011. The primary benefit of lithium-air technology is increased energy density; if fact, lithium-air battery technology has the potential to bring electric vehicle range up to competitive levels with internal combustion engines (Girishkumar et al., 2010). Lithium-air batteries with non-aqueous electrolytes (oxygen gas) can theoretically produce up to 3500 watt hours of energy per kilogram, or 1700 Wh/Kg in practical application (Kwabi, et al., 2014).
However, as it stands, lithium-air batteries are far from commercial development. There are large challenges which render this technology unusable for the time being. Specifically, two primary challenges include the reactivity of lithium with water, and the recharging of the pack by reversing the lithium-oxygen reaction. Current materials are insufficiently robust and reliable for preventing water from penetrating the lithium housing in lithium-air batteries, and merely a tiny amount of water finding its way to this store of lithium would result in critical failure. Resolving this challenge requires the development of an electrolyte that will permit only the selected reagents access to the lithium electrode. A second major challenge to lithium-air researchers is the rechargability of these batteries. Little progress has been made on this front, and researches continue to look for configurations of lithium-air batteries that will allow for the reversal of the lithium and oxygen reaction.
Ingram, Antony. “How Hard Is Lithium-Air Battery Research? Pretty Tough, Actually.” Green Car Reports. May 8, 2014.
Kwabi, D.G., Ortiz-Vitoriano, N., Freuneberger, S.A., Chen, Y., Imanishi, N., Bruce, P.G., and Shao-Horn, Y. (2014). Materials Challenges in Rechargeable Lithium-Air Batteries. Materials Research Society, 39, 443-452.
Girishkumar, G., McCloskey, B., Luntz, A. C., Swanson, S., and Wilcke, W. (2010). Lithium-Air Battery: Promise and Challenges. American Chemical Society.