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Technically, the biggest obstacle to an EV that can meet those demands is developing a cheap, lightweight, powerful, long-lasting battery. Nearly all EVs now on the road use some variation of the familiar lead-acid battery, which produces power by the reaction of lead with watered-down sulfuric acid. But even the best lead-acid batteries deteriorate in time and must be replaced at a jolting cost, up to $3,000 for the size and output required for an electric car. Other combinations of metals, electrolytes and oxidizing agents are being tried in batteries, and though they are generally more efficient and last longer, they often have unpleasant operating quirks. Sodium-sulfur and lithium-iron sulfide batteries, for instance, must function at dangerously high temperatures—up to 450° C (840° F).
Gulf & Western believes it has solved, or is on the verge of solving, most of the problems of the electric car. The company demonstrated three EVs near its Manhattan headquarters last week: the VW Rabbit and two Japanese-made vans, all powered by zinc-chloride Electric Engines. Range: an impressive 150 miles at 55 m.p.h., carrying a family of four. In its publicity, G&W assiduously avoids use of the word battery, partly to get away from the image of Grandma's old electric and also because its Electric Engine is unlike any battery ever made.
In simplest terms, the system makes electricity when chlorine gas reacts with zinc to produce zinc chloride (see diagram). The principle was discovered by Sir Humphry Davy in 1811, but no way was known to harness the powerful reaction before a G & W subsidiary in Detroit, Energy Development Associates, started working on it in 1972. Aided by several grants, including one for $11 million from DOE, G & W devised a system of pumps, valves, a refrigerator and a minicomputer that can produce a steady flow of power. G& W has spent $16 million of its own money on the zinc-chloride system thus far, including a pilot production plant.
The secret of the system is that its "stack" of 4,002 graphite plates is "passive"—that is, it does not shed particles in the electricity-making process. Thus it does not deteriorate, as do the metal plates in a conventional battery. The graphite plates also appear to be almost infinitely rechargeable: G&W says that a system like the ones in vehicles it demonstrated has been recharged 1,400 times, in four years of daily testing. The charging is done at a 220-volt A.C. outlet and typically takes six to eight hours.
The zinc-chloride system was first considered by G & W as a giant-size load leveler for electric utilities, a way of storing unused electricity during hours of light demand, then tapping it during heavy load periods. But G & W engineers realized that the system could be shaped to fit into a car's chassis. Instead of gradually weakening, as most other batteries do, the G & W device maintains full power for 95% of a charge. It is, asserts G & W's Judelson, totally safe, despite chlorine's image of hazardous railroad tank-car wrecks and World War I trench warfare. If the Electric Engine is cracked in a collision, insists the company, a harmless amount of chlorine will escape into the air, producing only the distinctive odor of a swimming pool.