Lithium-air accumulator

The lithium-air accumulator is a version of a rechargeable accumulator with a cell voltage of 2.96  V which is in laboratory research as of 2019 . The lithium-air accumulator with a metallic electrode made of lithium is not one of the lithium-ion accumulators in which lithium occurs as an ion source and only in chemically bound form, but uses the ambient air as an oxidizer.

There are several possible embodiments that have been the subject of various research for years. The reason for the research activities in this area is the theoretically high specific energy of 40.10 MJ / kg (11.14 kWh / kg). This means that lithium-air batteries would have a specific energy that is approx. 10 to 20 times higher than conventional lithium ion batteries and would approach the energy density of fuels for internal combustion engines.

construction

Charge and discharge cycle on the lithium-air accumulator

Despite the different details of the embodiments, the basic functional principle is the same for all lithium-air accumulator types. When the discharge is in the negative lithium - electrode while emitting a electron a positive lithium ion through the electrolyte , delivered to the positive electrode where the electron passes through an external conductor. There, oxygen (O ₂ ) is reduced, first lithium peroxide (Li ₂ O ₂ ) and then lithium oxide (Li ₂ O) being formed. When the battery is charged, this process is reversed: oxygen is released at the positive electrode, and metallic lithium is deposited on the negative electrode.

The positive electrode is made of mesoporous carbon and is not directly involved in the electrochemical process. The carbon serves as an electrical conductor and connection, the mesoporous structure to maximize the surface in order to facilitate the oxidation of the lithium ions and the access of the oxygen. The negative electrode consists of a block of metallic lithium. There is an electrolyte between the two electrodes, which can be liquid or solid. In the latter case, there is a solid-state accumulator.

Technical difficulties

The practical implementation of lithium-air accumulators encounters various difficulties, which is why this type of accumulator is in the research stage. The main problems of the lithium-air battery include:

• The mesoporous carbon electrode becomes clogged, which reduces the capacitance.
• The effects of pore size and their distribution in carbon are not fully understood.
• If the oxygen is taken from the ambient air, the water vapor (humidity) that is always present in the ambient air can impair the galvanic cell. If the cell is hermetically sealed, the high specific energy drops because the reservoir for the oxygen has to be taken into account.
• Particularly when charging lithium air batteries, the extremely reactive singlet oxygen is formed, which corrodes the cathode materials and massively reduces the cyclic service life.
• On the metallic lithium electrode, unwanted crystal growth and the formation of so-called dendrites can lead to internal electrical short circuits in the accumulator.

In view of the many difficulties, the battery material researcher M. Stanley Whittingham sees no chance of using lithium-air batteries in electric vehicles. Many researchers would even consider it a hopeless case.

In 2016, the Massachusetts Institute of Technology described a new design in which the oxygen is transferred between different lithium-oxygen compounds in a closed circuit in such a way that a gaseous state does not occur. At the same time, this design increases the efficiency considerably.

Historical

The high theoretical energy density of lithium-air batteries has long been known. After it had been shown that lithium could be used in aqueous concentrated LiOH solutions, a water-based lithium-air battery was also evaluated in the early 1980s with regard to its use in electric vehicles. The study carried out in the USA at the time spoke of a low probability of successful use, especially because the US lithium reserves would not be sufficient for widespread use. In 1987, a high-temperature lithium-air storage battery was introduced that used a solid electrolyte based on zirconium oxide . In 1996 a lithium-air battery with polymer electrolyte was presented.

Researchers

The lithium-air battery is not commercially available, much of the research on the lithium-air battery is done with public funds, e.g. B. at universities. But there are also companies that take part in research, e.g. B. the company PolyPlus Battery Company Inc. The company group Yardney Technical Products / Lithion Inc. has also worked on it. IBM started the Battery 500 project in 2009 , which also aimed to develop a lithium-air cell. In Germany, a consortium of companies including Schott AG , Volkswagen AG , Chemetall / Rockwood Lithium and Varta Microbattery worked on the lithium-air system.

Individual evidence

1. ↑ Thomas B. Reddy, Sohrab Hossain: Handbook Of Batteries . Ed .: David Linden, Thomas B. Reddy. 3. Edition. McGraw-Hill, 2002, ISBN 0-07-135978-8 , Chapter 34: Rechargeable Lithium Batteries (Ambient Temperature), pp. 34.1 - 34.4 .
2. ↑ G. Girishkumar, B. McCloskey, AC Luntz, S. Swanson, W. Wilcke: Lithium-Air Battery: Promise and Challenges . In: The Journal of Physical Chemistry Letters . tape 1 , no. 14 , July 15, 2010, p. 2193-2203 , doi : 10.1021 / jz1005384 .
3. ↑ A. Kraytsberg, Y. Ein-Eli: Review on Li – air batteries — Opportunities, limitations and perspective . In: Journal of Power Sources . tape 196 , no. 3 , 2011, p. 886-893 , doi : 10.1016 / j.jpowsour.2010.09.031 .
4. ↑ Singlet Oxygen Formation during the Charging Process of an Aprotic Lithium – Oxygen Battery J. Wandt, P. Jakes, J. Granwehr, HA Gasteiger, R.-A. Eichel, Angew. Chem. Int. Ed. 2016, 128, 7006-7009. doi: 10.1002 / anie.201602142
5. ↑ ^{a b} Richard van Noorden: The rechargeable revolution: A better battery . In: Nature . tape 507 , March 5, 2014, p. 26-28 , doi : 10.1038 / 507026a .
6. ↑ David L. Chandler: New lithium-oxygen battery greatly improves energy efficiency, longevity In: MIT News Office, July 25, 2016. Retrieved August 29, 2016.
7. ^ EL Littauer and KC Tsai: Anodic Behavior of Lithium in Aqueous Electrolytes . I. Transient passivation. In: The Electrochemical Society (Ed.): Journal of The Electrochemical Society . tape 123 , no. 6 , June 1976, ISSN  1945-7111 , p. 771-776 , doi : 10.1149 / 1.2132931 .
8. ^ ^{A b} Ralph J. Brodd, A. John Appleby, Ernest B. Yeager: Assessment of Research Needs for Advanced Battery Systems . Report of The Committee on Battery Materials Technology. Ed .: National Research Council (US). HMAB-390. National Academy Press, Washington, DC 1982, Part 3. Reports on Specific Battery Systems, 3.4. Metal Air and Zn-MnO ₂ Battery Systems, 3.4.5. Lithium-Air System, p. 92–94 ( limited preview in Google Book Search [accessed June 27, 2015]).
9. ^ Krystyna W. Semkow, Anthony F. Sammells: A Lithium Oxygen Secondary Battery . In: The Electrochemical Society (Ed.): Journal of The Electrochemical Society . tape 134 , no. 8 , August 1987, ISSN  1945-7111 , p. 2084-2085 , doi : 10.1149 / 1.2100826 .
10. ↑ Kuzhikalail M. Abraham, Zhiping Jiang: A Polymer Electrolyte ‐ Based Rechargeable Lithium / Oxygen Battery . In: The Electrochemical Society (Ed.): Journal of The Electrochemical Society . tape 143 , no. 1 , January 1996, ISSN  1945-7111 , p. 1-5 , doi : 10.1149 / 1.1836378 .
11. ↑ Patent US5510209 : Solid polymer electrolyte-based oxygen batteries. Applied on January 5, 1995 , published on April 23, 1996 , Applicant: Eic Laboratories, Inc., Inventor: Kuzhikalail M. Abraham, Zhiping Jiang (Expired Patent). ‌
12. ↑ Advanced Lithium Battery Technology - Lithium Air. (No longer available online.) PolyPlus Battery Company Inc., 2009, archived from the original on July 26, 2015 ; Retrieved July 29, 2015 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.   
13. ↑ Steven J. Visco: Manufacturing of Protected Lithium Electrodes for Advanced Lithium-Air, Lithium-Water & Lithium-Sulfur Batteries. (PDF) In: AMO PEER REVIEW, MAY 28-29, 2015. US Department of Energy, May 28, 2015, accessed on July 29, 2015 (The Advanced Manufacturing Office (AMO) conducted a Peer Review of its Research, Development, and Demonstration (RD&D), Facilities, and Analysis activities in Washington, DC, on May 28-29, 2015).  
14. ↑ Arthur Dobley, Joseph DiCarlo, Kuzhikalail M. Abraham: Non-aqueous Lithium-Air Batteries with an Advanced Cathode Structure. (PDF) In: The proceedings of the 41st Power Sources Conference, Philadelphia, PA June 2004. 2004, accessed on July 29, 2015 .  
15. ^ Winfried Wilcke: The Battery 500 Project. IBM Research, accessed July 29, 2015 .  
16. ↑ Christine Fuhr, Klaus Bernhard Hofmann: More range for electric cars. In: press releases from SCHOTT AG. SCHOTT AG, Mainz, January 23, 2013, accessed on July 29, 2015 .