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Project on Emerging Nanotechnologies
This column is by Philip Stiff, a member of the Project on Emerging Nanotechnologies team and a current student at the Georgetown Public Policy Institute:
High-capacity lithium-ion batteries are one of the core technologies of near-term clean energy solutions. These batteries have the potential to be at the heart of energy storage for transportation, episodic alternative energy and smart-grid electricity management. Many of these batteries will contain nanoscale lithium particles and other supplemental materials that will equip the electrode coatings inside the batteries for fast-charging and high-enduring voltage production. There are both foreseen and unexplored environmental, health and safety risks associated with the manufacture, use, recycling, and disposal of nanoscale lithium-ion batteries. While lithium itself is not known as a threat to the environment, there have been few studies performed to date on the risks of nanoscale-lithium particles. Members of the Institute of Electrical and Electronics Engineers (IEEE) have warned that current battery recycling and disposal processes may not be designed to handle this new battery technology properly. In order to provide assurances about the properties of this new material and establish processes for its end-of-life care, focused research on the environmental, health and safety aspects of lithium nanoparticles needs to be a priority.
October 27th, 2008
Lithium-ion Nanomaterial Batteries: Our new hope with a dose of caution
High capacity lithium-ion batteries are a major component of clean energy solutions. These batteries could be at the center of energy storage for transportation, episodic alternative energy (wind, solar, etc) and smart-grid electricity management. The Department of Energy is providing billions of dollars for cost-sharing programs to develop cost-competitive plug-in hybrid electric vehicle (PHEV) batteries (1). In the U.S., at least eight companies are racing to create a commuter-worthy battery pack for electric vehicles (EVs) and/or PHEVs that will not overheat during operation. These batteries may also be an important part of managing both traditional and alternative electricity production by providing electricity to houses, businesses, and utility companies when the vehicle is parked (2).
Most of these batteries will be comprised of nanoscale lithium and other electrolytic materials. Painting the electrode with nanoscale materials creates a large and accessible surface area that is optimal for fast and continuous electrolysis (3), allowing fast-charging and high and enduring voltage production. This improves upon current battery technology that is unable to provide enough power or endurance for a commuter-worthy vehicle without excessive weight or heat production. However, there are both foreseen and unknown environmental health and safety risks in the manufacture, use, recycling, and disposal of nanoscale-lithium batteries. The traditionally foreseen risks include overheating, ineffective crashworthiness, and overall electrical integrity that fall under the purview of multiple standards organizations including the Society of Automotive Engineers and safety regulatory agencies within the Department of Transportation.
Oversight on other potential risks, however, is lacking. The Project on Emerging Nanotechnologies' (PEN) extensive environmental, health and safety risk research inventory lists only one study on recycling and disposal implications for these new batteries (4). Additional Internet searches reveal only a handful of related environmental research on the disposal and recycling of nanoscale lithium-ion batteries. The end-of-life fate of these batteries seems dramatically overshadowed by the excitement over their potential and broad assumptions that the batteries are "non-toxic" (5).
A presentation at a recent Institute of Electrical and Electronics Engineers (IEEE) conference highlighted concerns that current battery recycling and disposal processes (largely involving burning and shredding) are not designed to handle this new battery technology. There is reason to suspect that nanoparticles can be dispersed during the recycling processes depending on the methods employed and filtration at recycling centers that may be underspecified (6,7). A study listed in the PEN risk research inventory assesses the state of battery recycling and makes recommendations for proper processing of this new technology (8). This study, led by Steven Sloop, investigates potential green chemical processing methods that could recover more pure materials and potentially create fewer hazards than traditional battery smelting processes. End-of-life innovations such as these are critical to making a "battery economy" more sustainable.
While lithium is not believed to bioaccumulate in the environment and is only toxic to life in extreme circumstances (9,10), this does not necessarily mean it is safe at the nanoscale. Many studies reveal that lithium is only considered non-toxic when administered to humans on a carefully prescribed basis (11,12). At the same time, lithium is arguably hostile to smaller life forms such as fish and rats (9,10). The effect of lithium at the nanoscale remains mostly unexplored, but several studies of other nanoscale materials that are considered safe in the bulk form have revealed some concerns, further making the case for risk research on nanoscale lithium.
There is little doubt that nano-engineered vehicle batteries will provide revolutionary methods for greening automobile technology. However, without focused risk research about the properties of these and other nanoscale materials used in batteries (besides nanoscale lithium), along with standardized processes for its end-of-life disposal, there is the possibility of creating circumstances that could lead to unexpected environmental or health problems.
(1) See U.S. Department of Energy, "DOE Announces $30 Million for Plug-in Hybrid Electric Vehicle Projects," announced 12 June 2008. Available at: http://www.energy.gov/news/6337.htm
(2) See "Plug-in Hybrids on the Horizon: Building a Business Case," EPRI Journal. Spring 2008 available at: http://mydocs.epri.com/docs/CorporateDocuments/EPRI_Journal/2008-Spring/1016422_PHEV.pdf
(3) See, for example, "QuantumSphere Files Key Patent on Revolutionary Technology to Increase lithium Ion (Li-ion) Battery Life," available at: http://www.nanotech-now.com/news.cgi?story_id=30665
(4) See http://www.nanotechproject.org/inventories/ehs/
(5) See, for example: Tesla Motors blog at http://www.teslamotors.com/blog4/?p=66
(6) Kohler, AR.; Som, C.; Helland, A.; Gottschalk, F. "Studying the potential release of carbon nanotubes throughout the application life cycle," Journal of Cleaner Production, 16 (8-9): 927-937.
(7) Olapiriyakul, S and Reggie J. Caudill. "A Framework for Risk Management and End-Of-Life (EOL) Analysis for Nanotechnology Products: A Case Study in lithium-Ion Batteries," Electronics and the Environment, 2008. ISEE 2008. IEEE International Symposium on. 19-22 May 2008. p 1-6. San Francisco, CA.
(8) See http://www.nanotechproject.org/inventories/ehs/browse/projects/6463/ and Sloop, Steven E. "Recycling Advanced Batteries," 2008 IEEE international symposium on electronics and the environment May 19-21, 2008, San Francisco, CA. See also "OnTo awarded contract to study lith ion recycling," available at: http://www.nanotech-now.com/news.cgi?story_id=22674
(9) Tkatcheva, V.; Holopainen, I.; Hyvärinen, H.; Kukkonen, J. "The responses of rainbow trout gills to high lithium and potassium concentrations in water." Ecotoxicology & Environmental Safety, Nov 2007, 68 (3): 419-425.
(10) Allagui, MS; Hfaiedh, N; Vincent, C; Guermazi, F; Murat, JC; Croute, F; El Feki A. "Changes in growth rate and thyroid- and sex-hormones blood levels in rats under sub-chronic lithium treatment," Human & Experimental Toxicology, 25 (5): 243-250.
(11) Yacobi, S.; Orney, A. "Is lithium a real tetratogen? What can we conclude from the prospective versus retrospective studies? A review," Israel Journal of Psychiatry and Related Sciences, 2008, 45 (2): 95-106.
(12) Aral, Hal; Vecchio-Sadus, Angelica. "Toxicity of lithium to humans and the environment-A literature review," Ecotoxicology & Environmental Safety, July 2008, 70 (3): 349-356.