From EV@SJSUVM1.SJSU.EDU Thu Oct 23 16:08 GMT 1997 Date: Thu, 23 Oct 1997 00:59:27 -0400 From: Bruce {EVangel} Parmenter Subject: EVLN(acs: SIDEBAR: Batteries approach goals set by USABC)-LONG 2/2 X-To: ev@sjsuvm1.sjsu.edu X-cc: news@calstart.org, CE96ed@aol.com, ebeaa@juno.com, hindle@aerovironment.com, Roy.Paulson@juno.com, atari@teleport.com, alt.binaries.electric-veh@staff.juno.com To: Multiple recipients of list EV EVLN(acs: SIDEBAR: Batteries approach goals set by USABC)-LONG 2/2 [The Internet Electric Vehicle List News. For Public EV informational purposes. Contact source for reprint rights.] --- {found at: } http://pubs.acs.org/hotartcl/cenear/971013/electric.html Chemical & Engineering News October 13, 1997 ELECTRIC VEHICLES GEAR UP Battery range, cost, and life limitations are gradually being overcome Sophie L. Wilkinson C&EN Washington ----------------------------------------------- [continued ... ] TO SIDEBAR: Batteries approach goals set by U.S. Advanced Battery Consortium --------------------------------------------------------------- Europe's consortium-Battery Research & Development in Europe, or BRADE-is focusing on NiMH and lithium-ion batteries, Stroven says. And Japan's Ministry of International Trade & Industry (MITI) is sponsoring a large program with the Lithium Battery Energy Storage Technology Research Association (LIBES), Tokyo, to develop lithium batteries for electric vehicles as well as for utility load leveling, Heitner says. The different battery technologies offer a broad range of performance, though developers hope they can all be improved. For example, lead-acid batteries can store about 35 watt-hours per kg, Stroven says, "and that is probably its major Achilles' heel. To get any kind of reasonable energy levels, the battery weight gets to be very high." That limits a vehicle running on this type of battery to a range of about 50 to 70 miles, he says. (Of course, range depends on the size of the vehicle and battery used, so the ranges given in this article can only provide a rough comparison between battery types.) Lead-acid batteries also have a poor cycle life, down around 300 to 350 recharge cycles, says Boone B. Owens, adjunct professor in the department of chemical engineering and materials science at the University of Minnesota, Minneapolis. Owens is also a consultant in the battery field and a technical specialist with Research International, Seattle. And if the battery is abused, it can give off hydrogen gas, Saft says. In addition, once the battery is exhausted, the lead must be recovered. Specific energy for nickel-cadmium batteries is around 45 watt-hours per kg, Saft says, while range is about 65 to 85 miles. Cost per kilowatt-hour is about $300 to $500, and lifetime is about 1,000 cycles, he says. Like valve-regulated lead-acid batteries, NiMH batteries are also sealed and maintenance-free, but their life is quite a bit longer, around eight years, Stroven says. And their current specific energy is up around the high 60s to low 70s watt-hours per kg, roughly double that of lead-acid batteries, Stroven says. That boosts vehicle range to about 100 to 120 miles, which would satisfy the demands of both fleet and retail customers, he adds. "Most people, retail customers particularly, want to have a 100-mile range, even though they may not necessarily need it on a day-to-day basis," Stroven notes. In this case, though, the customers must be considered right. "You have to make them feel comfortable or they won't consider buying your vehicle," he says. Unfortunately, NiMH batteries are relatively expensive, he notes. "Even in extremely high volumes, we would never be able to meet our target cost," which USABC has set for the long term at $100 per kWh. Stroven pegs NiMH costs at about $300 to $700 per kWh, while lead-acid is down around $150 to $200. However, the lead-acid battery also has a short life, wearing out after just a couple of years of continuous use, according to Stroven. NiMH batteries are "one of the safer systems out there," Saft says, "and they are environmentally benign. There are no materials that can't be recycled or that would create any problems." Zinc-air batteries are "getting a fresh look," Owens says, though they have some drawbacks. One company working in this area is B.A.T. International, Burbank, Calif. The firm, which is collaborating with battery manufacturer Kummerow Corp. of North America, Burbank, notes that "although the zinc-air has enormous energy capacity, it does not give up this energy very quickly," making it difficult to accelerate at highway speeds. Zinc-air batteries include a zinc plate, pellets, or powder as the anode and a catalyst-containing cathode that draws oxygen from the air, says Bill Wason, chief executive officer of B.A.T. subsidiary Ultra-Force Battery, [Image]Burbank. The electrolyte is a potassium hydroxide solution. B.A.T. International's The reaction yields a slurry minivan powered by zinc-air containing zinc, which has to batteries traveled a record be recovered to recharge the 478 miles on a single battery. The air electrode will charge. disintegrate if that is done while the zinc is in the battery, Wason says. So the zinc is removed from the battery for recharging. Drivers of zinc-air vehicles would refuel by swapping their used battery pack for a new one, leaving the used pack behind to be recharged. B.A.T. says the batteries are expected to cost just $100 per kWh when produced in volume, to have a range of 250 to 300 miles, and to last four years. Energy storage will be around 160 watt-hours per kg. The company, which is also working on nickel-cadmium and NiMH batteries, expects to have its zinc-air battery available for fleet vehicles within a year. Lithium-ion batteries, familiar to notebook computer owners, can store considerably more energy than NiMH on a weight basis, as much as 140 to 150 watt-hours per kg. But, Heitner says, "on a volume basis they are neck and neck." So, Stroven notes, "even though you can get appreciably more energy for the weight, you have to find a place to put it." Range may be about 150 to 200 miles for lithium-ion batteries and perhaps as much as 250 to 300 miles-"the same as a gasoline vehicle"-for lithium-polymer batteries, adds Riddell. Lithium battery life is expected to be about five or six years, and costs will probably be around $180 to $220 per kWh in high volume, Stroven says. Saft is more optimistic and believes lithium-ion batteries could get closer to USABC's midterm goal of $150 per kWh and will last eight to 10 years, in part, because they are sealed. Saft notes that the batteries contain some materials such as lithium salts that will "have to be recovered" when the battery life is exhausted, "though there is nothing that would be considered really hazardous." Another crucial issue concerns performance as the battery discharges. "The battery has to deliver enough power on a consistent basis to make sure the vehicle accelerates properly even as it's being discharged," Heitner says. "The vehicle shouldn't become sluggish and unsafe." The emphasis in advanced battery R&D is on energy density, cycle life, safety/reliability, and cost, Owens says. Unfortunately, there's a trade-off between energy content and cycle life, with a low-energy-density design generally lasting longer than a high-energy-density design, he says. Thermal management, charge time, and discharge rate (acceleration requires rapid discharge) also are important issues. And battery management itself is critical. "This is not a simple battery like in an electric shaver or flashlight, where you just turn it on and use it, and plug it in to charge it," Owens says. Electric vehicle battery packs are complex, containing several hundred individual electrochemical cells. With these batteries, "you need to make sure that all of the cells that make up the battery are operating correctly, that they're not being overcharged or overdischarged excessively. If a few cells short out here and there you won't necessarily see that, and it can lead to system failure," Owens says. Much of the advanced battery R&D is focused on lithium batteries. Lithium metal is very reactive and energetic as well as lightweight, making it attractive for electric vehicle batteries, Owens adds. In the 1970s and 1980s, early rechargeable lithium batteries for such products as watches and electric wheelchairs used lithium as the anode and compounds such as titanium disulfide or molybdenum disulfide as the cathode, he points out. As the battery discharged, the lithium metal oxidized and lithium ions traveled through the electrolyte and intercalated into the cathode. Recharging reversed the process, Owens says, but it didn't do it well. Rather than re-forming a flat electrode, the lithium would plate back out in the shape of dendrites, some of which could flake off and short out the battery, he says. This could lead to overheating of the organic liquid electrolyte and possible fires. Lithium-ion batteries for products such as camcorders and laptop computers can avoid these problems by replacing the lithium anode with one in which lithium ions are intercalated into various forms of carbon such as graphite. But carbon increases the size of the battery, so its energy density drops, and some of the carbons are "rather special" and drive up the cost, Owens says. Lithium-ion batteries with cobalt oxides as the cathode are already being evaluated in prototype batteries for vehicles, though they suffer from an environmental point of view from cobalt's heavy-metal status. Interest is now shifting to nickel oxide cathodes, Owens notes. High cost is an issue with both, though manganese oxides may in the future solve that problem. "Any of these cathodes could, in principle, be modified to work with a lithium metal anode if we ever get back to that," he says. Lithium cells, which at up to 4 V run at a much higher voltage than zinc-air (1.2 V), NiMH (1.3 to 1.4 V), and lead-acid (2.1 V), are more demanding on their electrolytes, Owens says. The electrolyte consequently must be more stable thermodynamically. For lithium-ion batteries, the electrolytes are lithium salts such as lithium hexafluoroarsenate (arsenic is a drawback) or lithium hexafluorophosphate dissolved in organic acids, he says. The liquid electrolyte can be replaced with a solid conducting polymer electrolyte similar to polyethylene oxide containing a lithium salt, forming a lithium-polymer battery. This has the benefit that the electrolyte won't vaporize as it warms up. However, "diffusion of ions is somewhat restricted in the polymer matrix and so ionic conductivity is low," Owens explains. That limits the discharge rate. But heating the polymer above about 60 ]C changes the polymer structure, making it less viscous, enhancing ion movement and battery performance, he says. One appealing feature of polymer electrolytes is that they could be formed as a thin membrane, which could be coated inexpensively with an anode on one side and a cathode on the other, Owens says. Internal resistance could be addressed by making the membranes very thin. But that leads to issues with manufacturing precision, how to stack these into a large battery, how to manage individual cells, and how to regulate heat flow, he says. 3M and electric utility company Hydro-QuTbec, Montreal, are heading a project with DOE, Argonne National Laboratory, and Lawrence Berkeley National Laboratory to develop these batteries, Heitner says. 3M is aiming for commercial launch in electric vehicles in 2000 at the earliest. There is also a lithium-ion battery category between solid and liquid electrolytes, in which a gel electrolyte is formed by adding a low molecular weight organic component to the polymer, Owens says. This can plasticize or swell the polymer, enhancing ionic conductivity at ambient temperatures. [Image] Longer range research in lithium and lithium-ion battery technology remains focused on new kinds of electrodes, Owens says. Cathode materials with very high energy density such as sulfur compounds or vanadium oxides are under study. And there is interest in returning to lithium itself to reduce the complexity and hence the cost of the battery, Owens notes. NiMH is also the focus of considerable research efforts. The active material in the cathode is nickel hydroxide. The anode is a hydrogen-storing alloy, primarily made of rare-earth materials and nickel. Other components, amounting to about 20% of the anode material, are manipulated to control cycle life, rate capability, and power, says Uwe Kvhler, project manager for NiMH battery development at VARTA Batterie, Kelkheim, Germany. VARTA is working on lead-acid and NiMH batteries for electric vehicles, and is collaborating with Duracell on the lithium-ion battery for USABC. Researchers are boosting NiMH performance by raising conductivity, tinkering with the physical structure of the cell (including the separation between the electrodes), and changing the kinetics (and hence the rate capability) of the battery's active materials. Different alloys, in which the relative amounts of additives such as cobalt, manganese, and aluminum are shifted, can be discharged at different rates. In fact, says Kvhler, "almost the whole periodic system can be introduced as an alloy component." Researchers are also working with nickel-titanium alloys. The electrolyte, which is primarily aqueous potassium hydroxide with lithium hydroxide and sodium hydroxide, can also be varied, Kvhler says. "The higher the potassium hydroxide, the better the rate capability. But for other reasons, for instance for improving the temperature range, additives like sodium or lithium can be advantageous." Which of all these battery types will win out? Although Saft sees lithium-ion batteries as a "product the automotive industry can standardize around," he also believes a whole range of battery technologies will coexist for "a good period of time," just as other vehicle options do. For instance, "not everybody wants to drive a V-8; some people will drive a four-cylinder vehicle," Saft says. With all the roadblocks in the path of electric vehicles, they may seem to be more trouble than they are worth. "But in the context of meeting a definition of a zero-emissions vehicle at the point where the vehicle is used, electric is the only thing we know how to do today," Stroven says. Other options don't appear to be practical in the near term. Cars that run on fuel cells, for example, still require a battery, are expensive, and may be several years from market, he says. Nevertheless, "just about everybody in the industry is working on them," he says. Hybrid vehicles also require an auxiliary power source, whether it be a turbine, diesel, or gasoline engine, "so they aren't emission free," Stroven says. And if a hybrid were designed to run off clean-burning natural gas, "the infrastructure wouldn't be there for refueling," he says. They are also pricey, since they "have most of the cost issues associated with an electric, and the cost associated with having an auxiliary power unit," Stroven says. Ironically, it's possible that car makers may not even need to rely on these exotic technologies. "It's not clear that you can't push conventional technology to extremely low levels of emissions, using modifications such as alternate fuel or improved emission controls," Heitner says. One example he mentions is Honda's "very clean" natural gas vehicle. But this won't stop development of other options. "What we're trying to do is create alternatives and let people try them out," Heitner says. So what's actually available on the electric-vehicle market, or coming in the near term? [Image] Electric vehicles that are already or soon will be on the market include GM's Saturn EV1 (left) and Ford's Ranger EV. GM's Saturn EV1 two-seat car and Chevrolet S-10 electric pickup are already available with lead-acid batteries. GM Ovonic, a joint venture between GM and Ovonic Battery Co. that is working in cooperation with DOE, will introduce NiMH batteries in the EV1 and S-10 next year. Toyota offers the RAV4-EV sport-utility vehicle in Japan (and for 1998 fleet models in the U.S.) and Honda is marketing the EV Plus, both of which run on NiMH batteries developed by Matsushita. Toyota also markets an electric bus in Japan that runs on lead-acid batteries. Ford's compact pickup truck, the Ranger, will debut with a valve-regulated, maintenance-free, 2,000-lb lead-acid battery in the 1998 model year, Stroven says. And Ford will use the NiMH battery in its 1999 Ranger EV vehicles. Initial target customers include utilities and fleets. Chrysler's Dodge Caravan and Plymouth Voyager EPIC (Electric Powered Interurban Commuter) minivans will come out with advanced lead-acid batteries in 1998 for California fleets. The company is also working with SAFT on NiMH for the minivan. SAFT's nickel-cadmium batteries are being used in cars such as the electric Peugeot 106 and Renault Clio in Europe. Nissan will introduce an electric vehicle in Japan's retail market early next year, and later in 1998 it will bring the Altra EV compact van to the U.S. fleet market. The vehicles will run on lithium-ion batteries developed by Sony, which is the "world leader" in this sector, Heitner says. Many other firms are working to bring electric vehicles to the market. Stadtner expects the Zebra Model Z two-seat convertible will be available in first-quarter 1998. It will run on advanced lead-acid batteries that take four hours to charge. In the next generation of vehicles, the company will switch to Unison Batteries' NiMH batteries, which will be leased to customers. Corbin-Pacific, Castroville, Calif., is marketing the three-wheel, one-passenger Sparrow, powered by a lead-acid battery. The car was designed for commuters and inner-city driving. The company notes that the vehicle can use car-pool lanes because it can be registered as a motorcycle and carries "100% of passenger capacity when driving alone." [Image] [Image] [Image] In 1899, the electric "la Jamais Contente" (top left) set a world land speed record of more than 100 km per hour. Zebra Motors Model Z (top right) has a sleek look but is a "no-frills car," designed to keep the price down. Corbin-Pacific's three-wheeled one-passenger Sparrow (bottom) is designed for commuting. While electric vehicles seemingly have caught the public's attention only recently, development in the field has been going on for decades. The first electric vehicle may have been built as early as the 1830s. In 1899, Belgian Camille Jenatzy reportedly drove his electric car, "la Jamais Contente" ("Never Satisfied" or "Never Happy") to a world land speed record in France, topping 100 km per hour. By 1900, more electric vehicles were registered in the U.S. than steam or gasoline vehicles, but the introduction of the convenient self-starter for gasoline-powered vehicles and Ford's Model T, and the spread of gas stations, diminished the relative popularity of electric vehicles. Perhaps that trend is nearing reversal. ... http://www.acs.org ( webmaster@acs.org ) Copyright 1997 by the American Chemical Society --- (BruceDP@iname.com) http://user.aol.com/brucedp/ _{Statements may not be my Employer's}_ ____ 800-537-2882 www.eaaev.org ~/__|o\__ 'Electric cruis'n the Santa Clara Valley' '@----- @'---(= Get Amp'd EVangel: messenger bringing good news 132V S-10 Blazer EAA San Jose EVents Officer http://user.aol.com/sjeaa/ Electric Vehicle List Editor http://crest.org/ev-list-archive/ EV Newsgroup contributing Editor alt.binaries.electric-veh AEL Renewable Energy News contributing Editor, EV & AE List sysop EVLN(acs: SIDEBAR: Batteries approach goals set by USABC)-LONG 2/2 Message-ID: