The invention: The nickel-iron alkaline battery was a lightweight, inexpensive portable power source for vehicles with electric motors.
The people behind the invention:
Thomas Alva Edison (1847-1931), American chemist, inventor,
and industrialist Henry Ford (1863-1947), American inventor and industrialist Charles F. Kettering (1876-1958), American engineer and inventor
A Three-Way Race
The earliest automobiles were little more than pairs of bicycles harnessed together within a rigid frame, and there was little agreement at first regarding the best power source for such contraptions. The steam engine, which was well established for railroad and ship transportation, required an external combustion area and a boiler. Internal combustion engines required hand cranking, which could cause injury if the motor backfired. Electric motors were attractive because they did not require the burning of fuel, but they required batteries that could store a considerable amount of energy and could be repeatedly recharged. Ninety percent of the motorcabs in use in New York City in 1899 were electrically powered.
The first practical storage battery, which was invented by the French physicist Gaston Plante in 1859, employed electrodes (conductors that bring electricity into and out of a conducting medium) of lead and lead oxide and a sulfuric acid electrolyte (a solution that conducts electricity). In somewhat improved form, this remained the only practical rechargeable battery at the beginning of the twentieth century. Edison considered the lead acid cell (battery) unsuitable as a power source for electric vehicles because using lead, one of the densest metals known, resulted in a heavy battery that added substantially to the power requirements of a motorcar. In addition, the use of an acid electrolyte required that the battery container be either nonmetallic or coated with a non-metal and thus less dependable than a steel container.
The Edison Battery
In 1900, Edison began experiments aimed at developing a rechargeable battery with inexpensive and lightweight metal electrodes and an alkaline electrolyte so that a metal container could be used. He had already been involved in manufacturing the nonrechargeable battery known as the Lalande cell, which had zinc and copper oxide electrodes and a highly alkaline sodium hydroxide electrolyte. Zinc electrodes could not be used in a rechargeable cell because the zinc would dissolve in the electrolyte. The copper electrode also turned out to be unsatisfactory. After much further experimentation, Edison settled on the nickel-iron system for his new storage battery. In this system, the power-producing reaction involved the conversion of nickel oxide to nickel hydroxide together with the oxidation of iron metal to iron oxide, with both materials in contact with a potassium hydroxide solution. When the battery was recharged, the nickel hydroxide was converted into oxide and the iron oxide was converted back to the pure metal.
Although the basic ingredients of the Edison cell were inexpensive, they could not readily be obtained in adequate purity for battery use. Edison set up a new chemical works to prepare the needed materials. He purchased impure nickel alloy, which was then dissolved in acid, purified, and converted to the hydroxide. He prepared pure iron powder by using a multiple-step process. For use in the battery, the reactant powders had to be packed in pockets made of nickel-plated steel that had been perforated to al-
low the iron and nickel powders to come into contact with the electrolyte. Because the nickel compounds were poor electrical conductors, a flaky type of graphite was mixed with the nickel hydroxide at this stage.
Sales of the new Edison storage battery began in 1904, but within six months it became apparent that the battery was subject to losses in power and a variety of other defects. Edison took the battery off
Thomas Alva Edison
Thomas Alva Edison (1847-1931) was America’s most famous and prolific inventor. His astonishing success story, rising from a home-schooled child who worked as a newsboy to a leader in American industry, was celebrated in children’s topics, biographies, and movies. Corporations still bear his name, and his inventions and improvements of others’ inventions—such as the light bulb, phonograph, and motion picture—shaped the way Americans live, work, and entertain themselves. The U.S. Patent Office issued Edison 1,093 patents during his lifetime, the most granted to one person.
Hailed as a genius, Edison himself emphasized the value of plain determination. Genius is one percent inspiration and 99 percent perspiration, he insisted. He also understood the value of working with others. In fact, one of his greatest contributions to American technology involved organized research. At age twenty-three he sold the rights to his first major invention, an improved ticker-tape machine for Wall Street brokers, for $40,000. He invested the money in building an industrial research laboratory, the first ever. It led to his large facilities at Menlo Park, New Jersey, and, later, labs in other locations. At times as many as one hundred people worked for him, some of whom, such as Nikola Tesla and Reginald Fessenden, became celebrated inventors in their own right.
At his labs Edison not only developed electrical items, such as the light bulb and storage battery; he also produced an efficient mimeograph and worked on innovations in metallurgy, organic chemistry, photography and motion pictures, and phonography. The phonograph, he once said, was his favorite invention. Edison never stopped working. He was still receiving patents the year he died.
the market in 1905 and offered full-price refunds for the defective batteries. Not a man to abandon an invention, however, he spent the next five years examining the failed batteries and refining his design. He discovered that the repeated charging and discharging of the battery caused a shift in the distribution of the graphite in the nickel hydroxide electrode. By using a different type of graphite, he was able to eliminate this problem and produce a very dependable power source.
The Ford Motor Company, founded by Henry Ford, a former Edison employee, began the large-scale production of gasoline-powered automobiles in 1903 and introduced the inexpensive, easy-to-drive Model T in 1908. The introduction of the improved Edison battery in 1910 gave a boost to electric car manufacturers, but their new position in the market would be short-lived. In 1911, Charles Kettering invented an electric starter for gasoline-powered vehicles that eliminated the need for troublesome and risky hand cranking. By 1915, this device was available on all gasoline-powered automobiles, and public interest in electrically powered cars rapidly diminished. Although the Kettering starter required a battery, it required much less capacity than an electric motor would have and was almost ideally suited to the six-volt lead-acid battery.
Impact
Edison lost the race to produce an electrical power source that would meet the needs of automotive transportation. Instead, the internal combustion engine developed by Henry Ford became the standard. Interest in electrically powered transportation diminished as immense reserves of crude oil, from which gasoline could be obtained, were discovered first in the southwestern United States and then on the Arabian peninsula. Nevertheless, the Edison cell found a variety of uses and has been manufactured continuously throughout most of the twentieth century much as Edison designed it.
Electrically powered trucks proved to be well suited for local deliveries, and some department stores maintained fleets of such trucks into the mid-1920′s. Electrical power is still preferable to internal combustion for indoor use, where exhaust fumes are a significant problem, so forklifts in factories and passenger transport vehi-
cles at airports still make use of the Edison-type power source. The Edison battery also continues to be used in mines, in railway signals, in some communications equipment, and as a highly reliable source of standby emergency power.
See also Compressed-air-accumulating power plant; Internal combustion engine; Photoelectric cell; Photovoltaic cell.
