Status of Advanced Battery Technologies for the EV Market

Commercialization Advanced Batteries of Jerry Mader Mader Associates STWACT Mader Associates has been working as a contractor for the South Coast Air Quality Management District District as well as domestic and offshore battery developers for the past several years During this period it has performed various assessments of advanced battery technology as well as established the Advanced Battery Task Force The following paper is Maders view of the status of battery technologies that are competing for the electric vehicle EV market being established by the California Air Resources Boards Zero Emission Vehicle ZEV Mandate The ZEV market is being competed for by various advanced battery technologies And given the likelihood of modifications to the Mandate the most promising technologies should capture the following market share during the initial 10 years LeadAcid 84 Nickel Metal Hydride 508 Sodium Nickel Chloride 78 and Lithium Ion 330 However today there is much less certainty associated with EV market prediction due to changes in the ZEV regulations INTRODUCTION On September 281990 the California Air Resources Board CARB adopted resolution 9058 Authors Current Address 375 Benvenue Avenue Los Altos California 94024 Based on a presentation at the 1996 Battery Conference 0885898596 500 0 1996 IEEE approving the lowemission vehicles and clean fuels regulations The regulations require the phased introduction of low emission vehicles Four categories of vehicles are defined including zeroemission vehicles ZEV CARBs ZEV Initiative requires auto makers that sell more than 35000 units per year in California to sell ZEVs on the following timetable 9 2 from 1998 to 2000 9 5 from 2001 to 2002 and 10 from 2003 and beyond From a technology perspective this means that electric vehicles EV having no tailpipe emissions are required to be sold in California beginning in 1998 by General Motors Ford Chrysler Nissan Toyota Mazda and Honda TECHNOLOGY DESCRIPTION Since the enactment of the ZEV Initiative the activity and resources being applied to battery development has increased dramatically A brief description of each of these systems will be given in this section Only technologies that are expected to influence the emerging ZEV market will be considered Standard lead acid traction batteries that deliver ranges of less than 50 miles are omitted as well as less developed technologies such as lithium polymer that have little chance of commercialization in the next several years The following brief descriptions are given to discriminate between the various systems IEEEAES Systems Magazine July 1996 17 Bipolar lead acid sealed systems that share a common Nickelcadmium positive nickel electrode produced plate for positive and negative electrodes by sintering nickel power and negative cadmium electrode Nickelmetalhydride utilizes positive nickel electrodes combined with a metal hydride negative electrode allowing for improved energy and material handling characteristics Zincair usually requires mechanical recharging by removing the spent zindelectrolyte mixture Others are developing electronic recharging systems It exhibits high energy Zincbromine a flow battery often described as a small chemical plant Charge and discharge requires circulation to deposit zinc on carbon plates and to carry discharged materials to a holding reservoir operational at 330 C where liquid sodium reacts with sulfur Issues regarding temperature containment and safety are being rigorously addressed by the developers Sodiumnickelchloride similarly a high temperature battery but with longer life characteristics Lithiumion an ambient temperature battery where lithium exists in an ionic state and swings from the positive to the negative electrodes This is a relatively new technology that is being vigorously pursued in Japan e Sodiumsulfur a high temperature battery BATTERY DEVELOPMENT CYCLE Each battery development effort travels down a definable path before it can reach successful commercialization This path is similar for all battery types and can be described in terms of a series of steps Each step must be completed and verified through testing before proceeding to the next step In most cases the steps require exceedingly more resources to complete as the project proceeds through the development cycle are defined below 1 cell developmentbench testing 2 module or sub battery developmentbench testing 3 battery pack developmentinvehicle testing 4 pilot plant developmentreliability testing 5 life safety and performance verification 6 production planning and business development and demonstration 7 commercial production The investment required to accomplish each of these steps varies for different battery types Nevertheless in gross terms battery development financial requirements can be categorized as follows cell module and pack development 90200 million Steps 12 and 3 above pilot plant verification and production planning 40100 million Steps 45 and 6 50100 million Step 7 180400 million Commercial production Total Approximate Development Cost It is difficult to determine the commercialization status of a battery until it has entered Step 4 pilot plant development Only then can the critical factors such as battery performance life and cost be verified and accurately projected for production units Table 1 Battery Range Comparison Table Energy whkg Range miles Leadacid Nickel cadmium Nickel hydride Zincair Zincbromine Sodiumsulfur Sodiumchloride Lithiumion 45 50 80 180 70 110 90 130 90 100 160 360 140 220 180 260 PERFORMANCE COMPARISON There are several terms used in EV battery development that quantify a batterys performance and allow for a comparison between battery types For the purposes of this paper the following list of terms are defined Specific energy the ratio of energy delivered by the battery to the weight of the battery measured in watt hours per kilogram whkg usually at a threehour discharge rate It is a quantifiable indicator of the range a battery will deliver under specified conditions battery to the weight of the battery measured in watts per kilogram wkg usually taken as the maximum deliverable over 30 seconds It is a Specificpower ratio of the power delivered by the 18 IEEE AES Systems Magazine July 1996 quantifiable indicator of the acceleration a battery will provide Cycle life the number of chargedischarge cycles that a battery can withstand before it fails End of life is usually defined by reaching a level of degradation at a percent of capacity most often 80 Buttery Life the time until a battery reaches the end of life criterion It is often measured through laboratory or invehicle testing but can be somewhat independent of use since most batteries have a specific shelr life Cost the cost of volume production for the battery manufacturer ie price to the auto manufacturer Cost is usually referred to in dollars per kilowatt hour The following table gives a comparison of battery performance based on the specific energy of the battery It shows the range on the EPA driving cycle what the battery will deliver if it were Impact with a gross vehicle weight of 2970 pounds and a battery weight of 1100 pounds For further comparison Table 2 presents power life and cost data ower Life and Cost Comparison Power wlkg Life years Cost kwh nickel metal hydride lithium ion sodium sulfur and sodium nickel chloride e The power and energy of all of these systems would satisfy the midterm USABC goals None of these advanced systems would be commercially available by 1998 but could be ready by 2002 Lithium ion will require the greatest time to develop and may not be available until 2005 Each system has merits and disadvantages relative to each other The panel therefore did not rank these four against each other but concluded that these technologies show more promise over other candidate battery systems such as zincair zinc bromine lithium iron disulfide and bipolar lead acid Almost two years ago the CARB technical staff issued a ZEV technical assessment report in April 1994 to support the May 1994 CARB Hearing on the 1998 ZEV Mandate The conclusion of the staff at that time was that four technologies nickel metal hydride sodium nickel chloride sodium sulfur and lithium metal disulfide are projected to meet the USABCs midterm goals and are expected to be available in the 1998 to 2000 time frame Interpreting comments made by the CARB technical staff at informal meetings at the workshops and through third parties the following is believed to be a ranking of the advanced battery systems as viewed by the CARB technical staff at the present time Leadacid Nickelcadmium Nickelhydride ZincAir Zincbromine odiumsulfur Sodiumchloride Lithiumion 3005150 2008350 2208 150 18071 00 757225 2605150 1507175 1808150 Assumes mature production of 20000 batteries per year A Battery Technical Panel was commissioned by CARB to make an independent assessment of the readiness of the various battery technologies to satisfy the California ZEV mandate in the 1998 to 2002 time frame The panel presented its preliminary conclusions at the 11 October ZEV Technology Review workshop held by CAR anel did not rank the advanced battery technologies but did conclude the following regarding 1 Lithium Ion 2 Nickel Metal Hydride and 3 Sodium Sulfur and Sodium Nickel Chloride Since early in 1994 the CARB technical staff had become knowledgeable about lithium ion through visits made by Sony and Nissan As a result they have become highly enthusiastic regarding the potential of this system They remain supporters of the nickel metal hydride system tending to believe the specific energy and cost figures that are projected The sodium batteries are rated somewhat lower due to the issues associated with hot batteries these being thermal efficiency and stand time heat loss freezethaw durability and life corrosion EV MARKFT POTENTIAL A clear definition of the future EV market in California continues to be an elusive target A market potential for the electric vehicle can however be defined using the ZEV Mandate as a basis Currently the Mandate is under scrutiny and changes are believed likely but at this time it remains the best available EV market predictor for California IEEE AES Systems Magazine July I996 19 Optimistic EV Market Scenario The optimistic EV market scenario is based upon the CARB ZEV Mandate remaining in effect in 1998 and continuing for 10 years through 2007 The potential EV market then in 1998 through 2000 is 2 of vehicle sales by the three US and the largest four Japanese vehicle manufacturers the Mandate increases to 5 in 2001 and then to 10 in 2003 The cumulative potential EV sales for this optimistic scenario for the 10year period is 1019100 vehicles Pessimistic EV Market Scenario The pessimistic EV market scenario is derived based upon the position currently being taken by the automotive industry with regard to the ZEV Mandate In July 1995 CARB held a workshop on the Marketability of ZEVs Several auto companies presented their estimate of the future EV market based upon the results of the respective companies market analysis The summary conclusions for the auto company presentations are as follows 1 The EV market in 1998 will be comprised primarily of leadacid battery powered vehicles used in fleets This fleet market will be limited to between 3500 and 5750 EVs annual sales 2 EVs will not significantly penetrate the personal market until a battery providing a useable vehicle range of 100 to 125 miles is available In addition to these conclusions GM presented its view that although the EV market will initially be limited to 35005750 units it could double with governmental incentives or grow to 10000 units with the implementation of widespread charging facilities Since it is reasonable to assume that some incentives will be available for the purpose of this analysis a 5000 ZEV penetration has been chosen for 1998 A 10year projection was developed assuming that 1 there will only be a leadacidbased fleet market from 1998 to 2000 and 2 CARB will adjust its 2 5 and 10 ZEV timeline to coincide with the advent of advanced batteries being commercially available in 2001 For this pessimistic scenario then the CARB Mandate schedule is adjusted as follows 2 in 2001 to 2003 5 in 2004 and 2005 and 10 in 2006 and beyond Table 3 Most Likely EV Market Scenario Percentage of Total to be 7EVs Percentage of Total Year Vehicle Sales Year Vehicle Sales to be ZEVs 1998 112 2003 5 1999 112 2004 5 2000 1 2005 10 2001 2 2006 10 2002 2 2007 10 introduction sales target will be reduced from 2 to 1112 The following ZEV sales schedule was developed for this most likely market scenario The cumulative potential EV market for this most likely scenario for the 10year period is 715200 vehicles IMPACT OF ZEV CREDIT FOR HYBRID VEHICLES A worst case sales scenario would be a further dilution of the market due to hybrids capturing a share of the ZEV market This could become a reality if CARB changes the Mandate to allow ZEV credits for hybrid vehicles For this case it is assumed that Class 2 partial credit hybrids arc available by 2001 which capture 10 of the ZEV market and that Class 1 full credit hybrids will be available in 2004 supplanting the Class 2 hybrids but capturing 25 of the ZEV market This penetration rate by hybrid vehicles I believed to be the maximum obtainable over this time period due to the added complexity of the system their higher cost as compared to pure EVs and the additional time required to commercialize them The cumulative potential EV market for this pessimistic scenario where hybrid vehicles capture a share of the ZEV market is 430700 vehicles Table 4 EV Potential Market Comparison Scenario Cumulative Potential EV Market Optimistic Pessimistic wlo Hybrids Pessimistic wl Hybrids Most Likely The cumulative potential EV sales for this pessimistic scenario for the 10year period is 577400 vehicles SUMMARY MOST LIKELY EV MARKET SCENARIO The most likely EV market scenario is that the ZEV Mandate will remain fixed for 1998 but that the 1009100 577400 430700 715200 Table 4 compares the cumulative potential EV market for four possible scenarios The annual potential EV sales is presented 20 IEEE AES Syslems Magazine July 1996 Table 5 Company Units Percentage GM 6000 22 Ford 4500 16 Chrysler 1600 6 Japanese Companies 15100 56 Total 27200 100 BATTERY MARKET SHARE The battery market share calculation is based on the most likely market potential scenarios that were defined above for the California market and on additional estimate of market penetration for the Northeast states Since there is a general understanding of the battery technologies which are preferred by the vehicle manufacturers the market was first segmented into the potential sales by manufacturer the Japanese manufacturers were taken as a group From these two data bases EV market potential and percent of market share by manufacturer an estimate can be made of the market share by battery technology over a 10year period It should be noted that this analysis will be conservative in that only the seven vehicle manufacturers which are required to offer vehicles for sale in California in 1998 were included As the mandate presently stands all vehicle manufacturers will have to offer vehicles for sale beginning in 2003 The market share estimate which is presented below is based upon the projected requirements for those companies to satisfy the 1998 ZEV Mandate The market share analysis further assumes that these percentages will not change throughout the 10year period Table 6 Vehicle Manufacturer Potential EV Market in thousands of vehicles Years GM Ford ChryslerJapanese Co Totals 19982000 61 45 17 156 279 20012004 602 438 164 1532 2735 20052007 1562 1136 426 3977 7102 Total 2225 1619 607 5665 10116 The estimate of the potential EV market by vehicle manufacturer is presented in Table 6 These figures were obtained by multiplying the market share percentages derived above to the combined California plus Northeast states most likely potential sales In order to estimate the potential market share for specific battery technologies assumptions had to be made regarding the timing as to when the vehicle manufacturers would be transitioning to advanced battery technologies These assumptions are as follows 1 Only leadacid batteries will penetrate the market from 1998 to 2000 2 The leadacid battery market share will remain constant throughout the 10year period 3 GM will use nickel metal hydride to fill its market share from 2001 to 2004 In 2005 GM will begin transitioning to lithium ion 50 of the vehicles will be equipped with Li ion and the other 50 with NiMH 4 Chrysler will stay with advanced leadacid throughout the 10year period However in 2001 they will begin employing NiMH batteries in 50 of their vehicles and in 75 of their vehicles in 2005 5 Ford will equip 50 of its vehicles beginning in 2001 with NiMH and the other half with NaNiC1 In 2005 Li ion will replace NiMH the vehicles in 2001 25 will be equipped with Pb Ac In 2004 Li ion will be used in 50 of the vehicles with the remainder being equipped with NiMH Employing these assumptions the following market 6 The Japanese will use nickelmetalhydride in 75 of shares by battery type are produced Table 7 Potential EV Battery Market Share in thousands of batteries Systems GM Ford Chrysler Japanese Co Totals PbAc 61 45 205 539 850 NiMH 1383 219 402 3137 5141 NaNiCl 787 787 Li ion 781 568 1988 3337 Total 2225 1619 607 5665 10116 CONCLUSION The CARB ZEV Mandate has created a significant potential EV market for advanced batteries From CARBs perspective the most promising advanced technologies are 1 Lithiumion 2 Nickel MetalHydride and 3 Sodium Sulfur and Sodium Nickel Chloride share as follows in Table 8 on next page The technologies are estimated to capture a market FUTURE CONSIDERATIONS On December 211995 the CARB Board directed the staff to redefine the ZEV Initiative that would suspend the Mandate until 2003 and replace it with a marketbased concept IEEE AES Systems Magazine July 1996 21 Table 8 Svstems Units PbAc 850k 84 NiMH 514lk 508 NaNiCl 787k 78 Li ion 3337k 330 Total 10116 1000 Under the marketbased approach the auto companies would agree to have production in place for up to 14000 units per year through 2002 as well as to demonstrate approximately 1500 advanced battery EVs The 10 mandate would become effective in 2003 In addition the auto companies would be required to make up the shortfall in pollution reduction due to the suspension of the 2 and 5 1998 and 2001 respectively mandated vehicle sales effective in late March 1996 Note that the overall effect of the new program on the market would be similar to the Most Likely EV Market Scenario shown above CARB program on the market development of EVs But it is clear that the CARBs current action is being seen as regulatory withdrawal And unless CARB can convince the investment and component industries that its agreements with the large auto companies contain This new ZEV program is expected to become It is difficult to measure the impact of the new sufficient safeguards a significant down turn will be observed in investment in EV battery development Proof of this has already occurred through the decision to close down the Silent Power Sodium Sulfur battery program ACKNOWLEDGMENTS The author wishes to acknowledge William Auxer for his contribution to this work as well as Dr Fritz Kalhammer and Dr David Douglas for their ongoing efforts in clarifying technical and institutional battery development issues REFERENCES 11 Kalhammer F et al December 11 1995 Performance and Availability of Batteries for Electric Vehicles A Report of the Battery Technical Advisory Panel California k r Resources Board Z Electric Hybrid Vehicle Technology 95 1995 3 The Eleventh Annual Battery Conference on Applications UK and International Press and Advances January 1996 California State University Long Beach 4 Mader J January 1995 Recommendations for Commercializing EV Battery Technology South Coast Air Quality Management District Contract Number 95020 5 Mader J September 1994 Electric Vehicle Battery Development Status South Coast Ar Quality Management District Contract Number 95020 Jerry Mader founded Mader Associates in 1992 to provide specialized consulting services to clients that are developing or evaluating electric vehicle EV technologies He has provided assistance to both government organizations and private industry domestically and abroad In California Mr Mader has worked with the South Coast Air Quality Management District the Energy Commission and Air Resources Board as well as Motive a Southern California vehicle developer Mr Mader has created market strategies for offshore battery developers and has established the Advance Battery Task Force ABTF to support the Zero Emission Vehicle ZEV Initiative As ABTF chairman Mr Mader works closely with the California Electric Transportation Coalition to provide information and give testimony in support of establishing the E V market Prior to establishing his consulting business Mr Mader was president and principle founder of The Electric Vehicle Development Corporation a consortium of electric utility and automotive companies He began his career in EV development in 1979 while at the Electric Power Research Institute in Palo Alto where he established its research program in electric transportation Mr Mader has a BS and MS in Engineering from the University of Michigan 31st Intersociety Energy Conversion Engineering Conference dusty Energy and Conservation in the 2Ist Century Omni Shoreham Hotel Washington DC 0 August 11161996 For more information see June issue page 45 i IEEE AES Systems Magazine ILL 1996