December 08, 2015
The growth of renewable energy systems has spurred a comeback for nickel-iron batteries. First developed by Thomas Edison in the early 1900s to power electric cars, Ni-Fe batteries fell out of favour as gasoline engines took hold. Thereafter their use was limited to specific applications in mining, telecommunications and railroad switching and signals.
Now, Ni-Fe batteries are re-gaining popularity with owners of independent solar energy systems because their expected life—about 25 years—is at least triple that of a lead-acid battery. Ni-Fe batteries cost twice as much, but are more durable than their lead-acid counterparts. They are extremely robust, are not sensitive to temperature variation and may be stored at any degree of charge without affecting performance, all issues that can affect other battery chemistries.
“After replacing one or two sets of lead-acid batteries in a very short time span, system owners have started looking for a new solution,” says Brandon Williams, CEO of Denver-based Iron Edison Battery Company, which produces batteries for off-grid applications. “For mission-critical applications, battery failure could have severe consequences, so many owners choose Ni-Fe batteries because of their extreme durability.”
Every battery chemistry is a compromise and for Ni-Fe batteries it is low energy density. That is being ameliorated with design improvement: a “sintered plate” that allows higher energy density and faster charging, as well as robust perforated steel “pocket plate” electrodes. The innate strength of Ni-Fe batteries, with technical improvement, makes it a valuable addition to the growing need for static energy storage.
Early motive power from nickel
Edison introduced Ni-Fe batteries as an alternative to lead-acid batteries around the turn of the 20th century. He spent years perfecting the technology for use in automobiles. In 1907 the first “Detroit Electric” car with a lead-acid battery was built. From 1911-1916 a Ni-Fe battery model—lighter and less corrosive than lead-acid—could be had at an extra cost.
The Detroit Electric was marketed to women under the assumption that they would prefer a car that would start immediately over a gasoline-powered model that had to be hand cranked. Several prominent women owned one, including Mamie Eisenhower, Eleanor Roosevelt and Henry Ford’s wife.
The car achieved sales of more than 1000 per year at its height. Sales began to slide in the 1920s as Ford’s internal combustion engines became cheaper and more efficient. The last of 13,000 Detroit Electrics was shipped in 1939, but Edison’s version of the Ni-Fe battery continued to be made by the Edison Battery Storage Company and its successor until 1975.