Argonne National Labs Ramping Up Lithium-Air Research and Development; Li-ion as EV “Bridge Technology”
|A Li-air cell. Source: Argonne. Click to enlarge.|
Argonne National Laboratory, which has contributed heavily to the research and development of Li-ion battery technology, is now pursuing research into Lithium-air batteries. Li-air batteries use a catalytic air cathode that converts oxygen to lithium peroxide; an electrolyte; and a lithium anode. Li-air batteries will have a capacity for energy storage that is five to 10 times greater than that of Li-ion batteries, which Argonne is characterizing as a bridge technology for electric vehicle applications.
Li-air batteries have both scientific and engineering challenges that need to be addressed. On the science side, the challenge is materials development, including creation of an advanced catalyst, a highly stable electrolyte, and efficient stabilization of the lithium anode metal. Engineering challenges include the development of high-porosity gas diffusion electrodes, ways of depositing the catalyst onto the cathode and developing a membrane to prevent oxygen crossover to the lithium anode.
The obstacles to Li-air batteries becoming a viable technology are formidable and will require innovations in materials science, chemistry and engineering. We have a history of taking on scientific challenges and overcoming them. Argonne is committed to developing Li-air battery technologies. In fact, we’ve made it a ‘grand research challenge’ at the laboratory.—Argonne Director Eric Isaacs.
|Argonne’s Dr. Khalil Amine on Li-air.|
The report of the DOE Basic Energy Sciences workshop on electrical energy storage, held 2-4 April 2007, found that recent advances in lithium-air systems had achieved a high efficiency for small systems at the relatively high cell voltage of close to 3 V. This, said the report, is a system that represents a battery that could approach the energy density of diesel fuel, in the range of 8,000–13,000 Wh/kg.
Although in the near term there do not appear to be feasible approaches to larger Li-air batteries, the system “probably represents one of the few viable approaches toward reaching the energy density of a liquid hydrocarbon fuel”, according to the report.
Accordingly, there are numerous research initiatives underway, with recent reports from Japan’s AIST (earlier post), IBM’s Almaden Lab (earlier post), and the University of Dayton (earlier post) among them.
|Li-air technical barriers and needs |
(from the DOE report Basic Research Needs for Electrical Energy Storage)
|Technical barriers and needs||Component(s)|
|Dependence on environmental conditions, maintaining access to air while minimizing evaporation of water||Cathode and separator|
|Limited operating temperature||Electrolyte|
|Necessity to remove CO2 from the air to prevent carbonation of electrolyte||Electrolyte|
|Potential for formation of shorting dendrites when charged||Zinc anode, separator|
|Non-uniform distribution of anode material develops as a result of solution and precipitation of reaction products||Anode, electrolyte|
|Limited power output||All|
|Low current densities resulting from resistive electrolyte||Solid electrolyte for lithium-air|
|Poor cycle life times|
The expectations for delivering viable automotive Li-air systems are not short-term. Development of a viable Li-air battery will require a technology breakthrough. Even given that, as with Li-ion batteries, it will take one to two decades before the technology could be commercially adopted, Argonne says.
This is not a near-term technology. It is going to take time and collaborations across several scientific disciplines to address the four main challenges of this battery development effort: safety, cost, life and performance.—Jeff Chamberlain, Senior Account Manager in Argonne’s Office of Technology Transfer
|Argonne’s Dr. Michael Thackeray on Li-air.|
Argonne National Laboratory has engaged in battery research and development for more than 40 years. More than 10 years ago the research facility made a strategic decision to expand its research of Lithium-ion batteries, with a particular focus on developing applications for electric cars. That decision, and subsequent investments for research by the US Department of Energy, have yielded technology transfer agreements, 149 inventions, more than 40 patents and four R&D 100 Awards.
Argonne has worked with several industrial partners on the commercialization of Li-ion batteries and battery materials, including companies such as EnerDel, Envia, BASF and Toda America. The lab is working with the Commonwealth of Kentucky to develop the Kentucky-Argonne National Battery Manufacturing Center, which will support the development of a viable US battery manufacturing industry.
More recently, DOE awarded the lab $8.8 million to build out and outfit three battery research facilities that will be used for battery prototyping, materials production scale-up and post-test analysis.