Nickel–zinc battery
 | This article needs attention from an expert in Energy. Please add a reason or a talk parameter to this template to explain the issue with the article. (November 2008) |
|
The nickel-zinc battery (sometimes abbreviated NiZn) is a type of rechargeable battery commonly used in cordless power tools, cordless telephone, digital cameras, battery operated lawn and garden tools, professional photography, electric bike and light electric vehicle sectors.
While nickel-zinc battery systems have been around for over 100 years, recent technological breakthroughs have made this technology viable and competitive with other commercially available rechargeable battery systems.
History
Developed by an Irish chemist, Dr. James J. Drumm (1897-1974)[1] and installed in four 2-car Drumm Railcar sets between 1932 and 1948 for use on the Dublin-Bray line. Although successful they were then withdrawn when the batteries wore out. Early nickel-zinc batteries were plagued by limited number of discharge cycles.
Thomas Edison was awarded a U.S. Patent for a recharged Nickel Zinc battery system in 1901 (U.S. Patent 684, 204).
Applications
Presently this battery technology has limited consumer availability with only AA cells offered for the digital camera market in some camera stores (Ritz Camera). Nickel-zinc is considered as the next generation batteries used for high drain applications, and is expected to replace lead-acid batteries because of their higher energy to mass ratio and higher power to mass ratio (up to 75% lighter for the same power), and are relatively cheap compared to nickel-cadmium batteries (expected to be priced somewhere in between NiCd and lead-acids, but have twice the energy storing capacity). NiZn can now be considered the industrial substitute for nickel-cadmium. The European Parliament has supported bans on cadmium based batteries and nickel-zinc offers the European power tool industry the most attractive alternative.
Electrochemistry
Charge Reaction: 2Ni(OH)2(s) + Zn(OH)2(s) ↔ 2Ni(OH)3(s) + Zn(s)
Note that the stoichiometry above is different than below, but the reactions are identical. Technically, water is consumed and generated on the charge and discharge cycles.
Discharge Reaction: H2O + Zn + 2NiOOH ↔ ZnO +2Ni(OH)2
Electrochemical open circuit voltage potential: ~1.73V
Technological Advantage
Higher performances than other alkaline batteries.
No use of heavy metals (mercury, lead or cadmium).
No use of metal hydrides (rare earth metals) that are difficult to recycle.
No flammable active material or organic electrolyte.
Simple recycling process, similar to the one in use for primary alkaline batteries. Zinc and nickel can be fully recycled.
1.6V cell voltage vs. 1.2V for NiCd and NiMH rechargeable cells.
Fewer cells required (compared to NiCd and NiMH)to achieve battery pack voltage reducing pack weight, size and improving pack reliability.
Both nickel and zinc are commonly occurring elements in nature and are not hazardous.
Nickel-zinc batteries when used with aqueous electrolytes may provide a "green" battery.
References
External links
- Powergenix - Developer and Manufacturer of nickel zinc batteries
- [1] - SCPS - Developer of industrial NiZn batteries
- [2] - Branch of Evionyx who has all infos on NiZn battery
- eVionyx - Developer and manufacturer of "flooded" prismatic NiZN battery
- eVionyx Taiwan - Taiwan manufacturer of eVionyx products