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HomeMy WebLinkAboutB16-0481_Review of Li Battery Pack2014_1482188418.pdfMechanical, Chemical Engineers and Hazardous Material Specialists 70 Saratoga Ave., Suite 200 * Santa Clara, CA 95051-7301 * Phone: (408) 261-3500 * Fax: (408) 261-4176 * E-mail: ies@intengr.com December 22, 2014 Erick Fong Design Manager, Retail Development 3500 Deer Creek Road Palo Alto, CA 94304 RE: Tesla Motors Model S (sedan) Lithium-Ion Battery Pack Chemical Constituents Review Thank you for the opportunity to provide specialized engineering services to Tesla Motors to review the chemicals and hazards associated with the lithium-ion battery pack which powers the Model S sedan SUMMARY After review of the MSDS and other technical documentation provided by Tesla Motors I have completed my review of the individual chemical components which make up the lithium-ion battery pack and have compared each chemical constituent on a pure material bases to the hazard classification system utilized by the 2013 California Fire (CFC) and Building Codes (CBC) which is based upon the 2012 International Fire (IFC) and Building (IBC) Codes. The Tesla battery pack contains approximately 7,000 lithium-ion battery cells at approximately 700 pounds. Each battery cell is approximately the same size and shape of an ordinary Alkaline “C-size” battery. After careful analysis and review of the individual chemical components which make up the Tesla lithium-ion battery pack, the hazardous materials classification of the constituents of the battery in a single model S are well below the maximum allowable quantities and therefore do not require a hazardous or H occupancy and can be stored or used in a Non-Hazardous Occupancy. DISCUSSION Lithium-Ion rechargeable batteries are currently used by people every day. These batteries are commonly found in laptop computers to cordless household telephones. The lithium-ion battery like any other chemical battery uses a series of complex chemical reactions to transfer electrons to provide electrical potential storage. Dry cell batteries, such as the lithium-ion type used in the Tesla Motors Model S sedan, contain an anode, cathode, and electrolyte. In a more common type of chemical cell battery, the wet cell battery, commonly found in conventional internal combustion engine vehicles is the “lead acid.” The differences between chemical batteries are the different chemicals used for the anode, cathode and electrolyte. In the common lead acid battery example, the anode is solid metal lead (Pb), the cathode is lead (IV) oxide (PbO2) and the electrolyte is approximately a 33% (vol) sulfuric acid (H2SO4) and water. The lithium-ion battery used by the Tesla Motor Company, the anode is graphite (carbon), the cathode is lithium cobalt oxide (LiCoO2), and the electrolyte is a mixture of organic liquids, dimethyl, ethyl, and ethylene carbonate, (see attached chemical list for quantities and hazard classification). Often, confusion arises when attempting to address the chemical hazards of a lithium-ion battery and the Building and Fire Codes pertaining to hazardous materials classifications and maximum allowable quantities in a non-hazardous (non H) occupancies. Although the common wet lead acid “car” batteries do contain solid metal Lead (Pb), a lithium-ion battery does not contain solid metallic lithium metal. This is analogous to claiming Sodium Chloride (a salt of Sodium or common table salt) contains pure Sodium Metal and should therefore be regulated as a severely hazardous water reactive class three material. Common sense tells us sodium chloride is not a severely water reactive hazardous material. 12/19/16 Lithium Ion Battery Pack Chemical Constituents Review December 22, 2014 Page 2 of 3 A more detailed description of the composition and construction of a lithium-ion battery by the America Physics Society from their web portal http://www.physicscentral.com/explore/action/lithium-1.cfm is attached. Below is a list of the chemical constituents of the Tesla Motors Modes S battery, its chemical components, approximate quantities, and Building Code Hazard Class Definition. 2014 UPDATED LITERATURE REVIEW On August 6, 2014 the U.S. Department of Transportation’s (DOT) Pipeline and Hazardous Materials Safety Administration released its final rule on transporting lithium-ion batteries which are to go into effect on February 6th 2015. Although this review is not intended to cover transportation (shipping) of lithium-ion batteries, it is noteworthy that the DOT hazardous materials classification guide for shipping currently list lithium-ion batteries as a class 9 packing group II material. This is the miscellaneous hazardous materials category (for shipping) which encompasses all hazardous materials that do not fit into one of the definitions listed in Class 1 through Class 8. Therefore, for shipping purposes, the US DOT CFR 172 currently lists lithium-ion batteries as not meeting the definition of one of the other 8 hazardous categories, which include material such as flammable or corrosive liquids (Class 3 or Class 8 respectively) being offered for shipping. “Hazardous Materials: Transportation of Lithium Batteries; Final Rule” http://www.gpo.gov/fdsys/pkg/FR-2014-08-06/pdf/2014-18146.pdf. CHEMICAL DATA REVIEW Weight of Batteries in Pack = 700 LBS. Battery Technology: Lithium-Ion Battery Type: Secondary (rechargeable) Dry Cell Battery Chemistry Type: Lithium Cobalt Oxide (LiCoO2) Materials/Ingredients Physical CAS No.Calculated *IBC/CBC Hazard Class Calculated Calculated State WT% Pounds/Car Liters/Car Lithium Cobalt Oxide (LiCoO2) Solid 12190-79-3 35% IRR, OHH, SENS 245 N/A Graphite Solid 7782-42-5 10% IRR 70 Hexafluoropropylene-vinylidene fluoride Copolymer Solid 9011-17-0 15% IRR 105 Lithium Hexofluorophosphate Solid 21324-40-3 5% CORR 35 Acetylene Black Solid 1333-86-4 2% N/R 14 Dimethyl Carbonate Liquid 616-38-6 11% FL-1B, IRR, OHH 77 32.7 Ethyl Methyl Carbonate Liquid 623-53-0 11% CL-IIIB, IRR 77 34.7 Ethylene Carbonate Liquid 96-49-1 11% IRR 77 26.5 TOTAL 100% 700 Notes: *Although Irritant, Other Health Hazard, and Sensitizers are no longer regulated hazardous materials per the 2013 CBC/CFC they are shown in the above table for clarity. Table Abbreviations: IRR = Irritant, OHH = Other Health Hazard, SENS = Sensitizer, CORR = Corrosive, FL-1B = Flammable, Liquid Class 1-B, CL-IIIB = Combustible Liquid Class III-B, IBC = 2012 International Building Code, CBC = 2013 California Building Code 12/19/16 Lithium Ion Battery Pack Chemical Constituents Review December 22, 2014 Page 3 of 3 MOTOR VEHICLE REPAIR GARAGES OCCUPANCY GROUP Motor vehicle repair garages complying with the maximum allowable quantities of hazardous materials listed in Table 307.1(1) (below MAQ) fall into occupancy group S-1 “Moderate-Hazard Storage” per 2013 CBC section 311. Without direct guidance from the current Building/Fire codes or agreement between agencies, such as NFPA, on how to properly classify lithium-ion batteries (see “2014 updated literature review” above) one method is to look at the individual constituents of the battery pack on a Tesla Motors model S. Of the listed materials contained within a lithium cobalt oxide (LiCoO2) battery (see table above) we can attempt to determine de minimis quantity of full size vehicle battery packs. The most limited quantity (MAQ) material in the table above is dimethyl carbonate, which is a flammable liquid Class 1-B (FL-1B). Although it would be essentially impossible to extract dimethyl carbonate from the electrolyte slurry contained within the 7,000 individual battery cells, and ignoring the reduction in flammability characteristics when pure materials are diluted/mixed with other less flammable materials, we shall use this as a starting point. The 2013 CBC/CFC limits the maximum quantity of FL-1B in a non-hazardous occupancy located on the 1st floor of a sprinklered building to 240 liquid gallons. The quantity of Dimethyl Carbonate in a single Original Manufacturer Equipment (OEM) Tesla Model S battery pack is approximately 32.7 liters (8.64 gallons). Divide 240 gallons by 8.64 and we get 27.8 Tesla Model S vehicles. This is an extremely conservative method of classifying hazardous materials and should not be taken as a specific standard method. This review is attempting to identify a quantity which is de minimis under current Building and Fire Codes and determine that S-1 is an appropriate occupancy group for Motor Vehicle Repair Garages which services the all-electric powered Tesla Model S. Always check with the Local Authority Having Jurisdiction (AHJ) for local adopted ordinances which may be stricter than the State adopted base Codes. ATTACHMENTS 1) “Lithium-Ion batteries, Delivering a Charge” from American Physical Society © 2011 http://www.physicscentral.com/explore/action/lithium-1.cfm 2) “Pure Chemical Class List” for the CBC/IBC classification of each of the above chemicals, and quantities contained in a single Tesla Model S sedan battery pack. 3) “HMIS Summary – 1st Floor, Sprinklered Bldg.” For a comparison of the 2013 CFC/CBC Table 307.1 Maximum Allowable Quantity per control area of Hazardous Materials of the chemical constituents of a single battery pack on a Tesla Motors Model S. CONCLUSION If we were to separate the entire battery pack of one Tesla Motors Model S sedan, chemically separate out the raw chemical components, we would find the hazardous materials classification of the chemicals, per the 2013 CBC/CFC, are well below the maximum allowable quantities per table 307.1 and therefore do not require a hazardous or H-occupancy and can be stored or used in a Non-Hazardous Occupancy, per CBC table 307.1. Furthermore the common lithium-ion battery does not contain pure metal lithium, but instead contains a lithium salt which is not water reactive, per the 2013 CBC/CFC. Sincerely, Tim Bancroft, P.E. Chemical Engineer California Registered Professional Engineer Lic # CH 6225 NCEES Record #46770 12/19/16