Battery development makes good progress - C&EN Global Enterprise

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Technology

Battery development makes good progress Improvements to conventional lead-acid types, new varieties with high capacity for energy storage described at ERDA-sponsored conference The "superbattery" is getting closer to reality. There are prototypes of a halfdozen or more different kinds beginning to appear in research laboratories around the country. And if development follows the schedule set by Congress and the Energy Research & Development Administration, the first 2500 electric vehicles powered with improved batteries will be on the road by the end of next year. The most advanced types of batteries under development will almost certainly not be ready for thisfirstbatch of electric cars. But progress on battery development at all levels has been substantial during the past year, and researchers in thefieldare optimistic about the potential of several of the new types of batteries under development. A progress report on battery development has come from the first annual coordination meeting of ERDA's battery contractors held last month. Sponsored by ERDA and Argonne National Laboratory, the two-day conference brought together 190 representatives of participating laboratories. The bulk of research

in the field is at least partially supported by ERDA and so was represented at the sessions. Batteries under development range from slight improvements on conventional lead-acid batteries to a number of new varieties that are expected to have up to six times the energy storing capacity per unit weight of conventional batteries. Among those receiving most attention are those that use molten salts either as electrode or electrolyte and operate at temperatures from 300 to 500° C. ERDA has identified two major potential markets for such batteries. One is for load leveling by electric power utilities. Power plants could be run more efficiently if they could store power generated during off-peak periods for transmission when load is heaviest. In addition, many utilities generate the bulk of their power from either coal or nuclear fuel but use petroleum-powered turbines to provide extra power at peak-load periods. Load leveling would thus free much of the petroleum that is now used for electric power generation. The second major use envisioned for the new batteries is to power electric vehicles. Nonpolluting and quiet, these vehicles could become a major mode of transportation in the next decade if they can be developed with adequate power and range and at reasonable cost. It also seems likely that for solar and wind power to reach their full potential, an efficient means of storing energy for use as it is needed will have to be developed. Ad-

New electric vehicle batteries improve driving range, speed

Source: Energy Research & Development Administration

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C&ENFeb. 21, 1977

vanced batteries are one of many systems being investigated for this use. ERDA's budget authority for the battery development program in 1976 was $7.5 million. For 1977, the agency's authorization is $12.7 million. In addition, under a separate law enacted last year to promote rapid development of electric vehicles, the agency is authorized to spend between $10 million and $30 million on batteries for electric vehicles in 1977. How extensive this program actually will be this year has not been made public by the agency, in part because the proposed 1977 budget contains no appropriation for this research. The agency expects to have its plans in the area of electric vehicle development and a supplemental budget request ready by early March. The ERDA effort falls into two broad classes: work on near-term batteries, where there is hope that improvements can be made quickly and large-scale production of improved batteries begun in the next few years, and more fundamental work on advanced batteries. Because of last year's Electric & Hybrid Vehicle Research, Development & Demonstration Act, the emphasis for much of the nearterm battery development is on a battery for electric vehicles. The act calls for delivery of 2500 electric vehicles with improved batteries by December 1978, and for a second 5000 vehicles with further improved batteries by 1983. Directed by Argonne National Laboratory, battery development to meet these goals is taking place at eight companies. It focuses on three types of batteries: lead-acid, nickel-zinc, and nickel-iron. Of the three, only lead-acid batteries also are being developed for near-term utility applications. Demonstration electric vehicles available now use lead-acid batteries and have operating ranges of only 20 to 25 miles at 55 mph before they must be recharged. The U.S. Postal Service currently is testing a fleet of about 370 such vehicles for their long-term performance. Although the study is not completed there have been some rear axle failures in these vehicles, suggesting that the weight of the batteries may be too great for the present vehicle design. Tentative plans call for the Postal Service to purchase an additional 1000 electric vehicles in 1977 or 1978. The range of lead-acid-powered electric vehicles could be about doubled, researchers believe, by a number of relatively minor changes in the battery. A major focus of research is to lighten the battery while retaining its charge storage capacity. These projects replace the battery's solid lead electrodes with a lighter

weight lead mesh or with electrodes made from various lead-antimony alloys. Other modifications being investigated include changes in the separator material and the use of additives in the electrolyte. Such modifications are intended to raise the specific energy of the batteries (the amount of energy stored per unit weight) from the present 30 watt-hours per kilo­ gram (wh/kg) to 40 wh/kg in 1978 and 50 wh/kg in 1980. Cycle life of the battery, or the number of times the battery can be charged and discharged, also is expected to rise from its present level of 700 cycles to 800 cycles by 1978 and 1000 cycles by 1980. Both nickel-iron and nickel-zinc bat­ teries have the potential for modest im­ provement over lead-acid batteries for electric vehicle use by 1980. Nickel-iron batteries have longer cycle lives, about 1500 cycles now. Improvements may bring them to 2000 cycles by 1980. Their spe­ cific energy is roughly comparable to that of lead-acid batteries, projected to be 60 wh/kg by 1980. So far, a 16.5-kwh nickeliron battery, built by Westinghouse, is the largest battery of this type to be tested. Another developer, Eagle-Picher Indus­ tries, has built and tested the iron elec­ trodes for a 50-kwh battery. Nickel-zinc batteries have a cycle life now of only about 200 cycles. Improve­ ments are likely to raise this level to 70 cycles by 1980. The specific energy of the battery, however, is better than for either lead-acid or nickel-iron—about 70 wh/kg now and expected to be about 90 wh/kg by 1980. Among the advanced batteries being developed, two are receiving most of ERDA's research support. These are the lithium-sulfur and sodium-sulfur bat­ teries, which together received about two thirds of ERDA's battery program budget in 1976. A third advanced battery, the zinc-chloride battery, also was singled out at the meeting and is well along in devel­ opment. The lithium-sulfur battery, being de­ veloped by Argonne and five outside contractors, resembles conventional bat-

ERDA projects $16 million for battery research in 1978 $ Millions

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BOOZ-ALLEN & HAMILTON'S

Arnold H. Pelofsky The coal dilemma shows few signs of be­ coming less of a dilemma in the near future. One reason, says Dr. Arnold H. Pelofsky, manager of alternate fuel programs for Booz-Allen & Hamilton Inc., is that neither Congress nor the public is possessed by a realistic sense of urgency. Thus the coal dilemma: the apparent inability of the nation to press on with utilization of its vast coal reserves as an enlarged basic energy re­ source. Pelofsky, who chaired the recent American Chemical Society Division of Industrial & Engineering Chemistry sym­ posium on the coal dilemma (C&EN, Feb. 14, page 24) also notes that Congress doesn't seem to appreciate the lag times involved in designing and building coal conversion plants. This, he suggests, might be the reason why loan guarantee legisla­ tion has been defeated when it has come to a vote. Meanwhile, the national deficit in balance of payments is growing, largely because of high imported gas and oil prices. Pelofsky believes that every $10,000 that leaves the country means loss of another job. It also contributes to inflationary trends. Public apathy about the coal dilemma may be due to public exposure. Pelofsky believes that the broadcast media and the press can decrease public apathy by pre­ senting energy-related problems with a treatment similar to that accorded medicine and health problems. Then, perhaps, there would be a general appreciation of the specific coal issue as well as the broader problems of the energy crisis. If Congress seems to be incapable of action on coal, one way to induce action is with a deluge of letters from constituents. Pelofsky is a firm believer in writing to Congressmen and suggests that, even if it sounds corny and naive, it also is very ef­ fective. This winter's gas shortages might provide the boost in public resolve that would get it started. It takes up to 10 years to design and build a coal conversion plant with a typical cap­ ital investment of about $1 billion. That means that there can be no significant en­ ergy input to the economy from coal con­ version processes before 1985, even if the capital were available now. One thing that puzzles Pelofsky is the apparent inability of the U.S. to act in an­ ticipation of future crises. When face to face with a crisis itself, the country usually responds admirably. Maybe the severe winter will provide the necessary crisis to generate a concerted response, he says. Part of that response will have to be legis­ lation devoted to a loan guarantee program for coal conversion plant construction. Pelofsky notes that not even a giant cor­ poration can provide the collateral for a

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a Program was under the Atomic Energy Commission. Note: Figures are budget authority for battery research. Source: Energy Research & Development Administration

Above all there is lack of a national energy policy that encompasses problems of coal billion-dollar plant that has yet to be proved in commercial service. Another thing that must be done is to obtain quick agreement on a compromise between environmental standards and en­ ergy necessity. Pelofsky is convinced that most of the environmental standards now in force or in prospect have been written without any clear idea of what environ­ mental impact really means. Not every last facet of environmental impact can be foreseen, he says, before a plant starts operation. However, that doesn't mean that there must be a great environmental risk. Environmental protection must be built into any new construction, but that construction, he says, must not be foredoomed by un­ realistic, if well intentioned, environmental restrictions. At present, the impediments to resolving the coal dilemma, and consequently of taking steps toward solving national energy problems, are primarily educational and legislative. This may change, Pelofsky says, if gas shortages grow and oil prices esca­ late, but anything short of a personally re­ alized crisis among the citizenry won't produce any concerted action. Pelofsky believes that above all there is lack of a national energy policy that en­ compasses the problems of coal as well as those of oil shale, nuclear power, and oil and gas. It has become a truism that no new energy industries can be started without government action. That action presently is stymied or retarded by the tactics of en­ vironmentalists and other partisans. Citizen pressure, he says, is the best antidote. Even though there has been no demon­ stration of either gasification or liquefaction of coal on a commercial scale in the U.S., there has been success elsewhere. The residuum of coal conversion technology from the previous age of coal, Pelofsky says, leaves no doubt that the technology is available. The immediate problem is the commitment to go ahead. D Feb. 21, 1977 C&EN 29

veloping materials that will resist corrosion by lithium at elevated temperatures and still not be prohibitively expensive. A 1-kwh cell, approximately the size of the unit cell that will be needed for either utility or vehicle applications, currently is being tested for cycle lifetime by its developer, Atomics International division of Rockwell International. So far this prototype battery has completed 3300 hours of testing or 230 discharge cycles. Its specific energy is 75 to 80 wh/kg. ERDA is "reasonably optimistic" about having a prototype battery ready for vehicle testing by the end of this year. By the early 1980's the agency hopes that the battery will be well enough developed that automobile makers can decide whether it is feasible commercially. A battery for electric utility applications is scheduled to be ready for testing in 1982. The other major development effort in molten salt batteries is on the sodiumsulfur battery. Dow Chemical and Ford Motor Co. are the main ERDA contracArgonne researchers examine lithium/metal sulfide battery cell tors for this development, and others are involved in nonfederally supported reteries more than the other advanced bat- its molten salt electrolyte conducts lithi- search in this area. Unlike the lithiumteries do. Like a conventional battery it um ions most efficiently at temperatures sulfur battery, this battery uses molten has solid electrodes (in this case a lithium between 415 and 430° C. salt for its electrodes—sodium for the alloy for the negative electrode and a Specific energies for prototype lith- negative electrode and a mixture of sulfur metal sulfide for the positive electrode), ium-sulfur batteries have been tested at and sodium polysulfide as the positive a liquid electrolyte (a mixture of lithium 150 wh/kg, a value that should translate electrode. The electrolyte is a solid cechloride and potassium chloride), and a into a range of greater than 100 miles at 55 ramic material. The battery operates at ceramic material separating the half-cells. mph for an electric vehicle powered by 300 to 350° C. Here the similarity ends, however, since these cells. Research now focuses on deAs with the lithium-sulfur battery, a major problem with molten salt batteries has been corrosion, in this case caused by molten sulfur. Research now focuses on scale-up and on increasing the cycle life of the battery. Recent tests on engineeringscale batteries at Ford Motor Co. give specific energies of 118 to 183 wh/kg with lifetimes of about 200 cycles. This energy output is acceptable for both electric vehicle and utility applications, but the cycle lifetime needs to be improved to about 1000 cycles to meet ERDA criteria. Smaller, laboratory-scale sodium-sulfur cells already have been demonstrated with lOOO-cycle lifetimes. Plans call for a sodium-sulfur battery to be ready for testing in a vehicle within two to three years and testing for utility applications in 1981. In hazardous work spaces, where accidental One of ERDA's advanced batteries may contact with corrosive substances could cause be ready for inclusion in ERDA's first irreparable eye injury, your employees deserve batch of demonstration electric vehicles, the best possible odds for preserving sight. which will be coming out next year. That Your safest b e t . . . a Haws Eye-Wash is the zinc-chlorine battery. This battery Fountain, accessible to all workers. Haws dual operates at slightly refrigerated temperautomatic pressure compensation devices atures (0 to 10° C). Metallic zinc reacts control variations in supply line pressure with chlorine gas to release energy. The between 20 and 100 PSI, assure optimum firstelectrolyte is aqueous zinc chloride. Reaid with generous volumes of water from the search is now aimed at scale-up. patented Soft-Flo heads. ERDA expects to have thefirst50-kwh Get all the facts from your nearest zinc-chlorine battery for electric vehicles Haws Safety Equipment Distributor, or delivered this fall and another by the end contact the Safety Division, Haws of the year. A 100-kwh battery for utility Drinking Faucet Co., 1443 Fourth St., load leveling also is scheduled to be ready Berkeley, CA 94710. for testing this year. Development of this system is being carried out by Energy Development Associates, a joint venture of Gulf & Western Industries and Hooker HwKNuY LuUrMral Model 7760 with 9100 dust cover Chemical division of Occidental Petroleum. D

Dont gamble 9 with. employees' vision!

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C&ENFeb. 21, 1977