Silver-oxide battery

	Email		Print
	Bookmark		Link

Silver-oxide battery

A silver oxide battery (IEC code: S), also known as a silver–zinc battery, is a primary cell

Primary cell

A primary cell is any kind of electrochemical cell in which the electrochemistry chemical reaction of interest is not reversible, so used in disposable battery ....
(although it may be used as a secondary cell with an open circuit potential of 1.86 volts). Silver oxide batteries have a long life and very high energy/weight ratio, but a prohibitive cost for most applications due to the high price of silver. They are available in either very small sizes as button cell

Button cell

A watch battery, button cell, silver button cell, or coin cell is a small form-factor battery designed for use in wrist watches, pocket calculators, hearing aids, and similar compact portable electronics products....
s where the amount of silver used is small and not a significant contributor to the overall product costs, or in large custom design batteries where the superior performance characteristics of the silver oxide chemistry

Chemistry

Chemistry is the science concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions....
outweigh cost considerations.

Discussion

Ask a question about 'Silver-oxide battery'

Start a new discussion about 'Silver-oxide battery'

Answer questions from other users

Full Discussion Forum

Encyclopedia

A silver oxide battery (IEC code: S), also known as a silver–zinc battery, is a primary cell

Primary cell

Button cell

Chemistry

Chemistry is the science concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions....
outweigh cost considerations. The large cells found some applications with the military, for example in Mark 37 torpedo

Mark 37 torpedo

The Mark 37 torpedo is a torpedo with electrical propulsion, developed for the US Navy after World War II. It entered service with the US Navy in the early 1950s, with over 3,300 produced....
es or on Alfa class submarine

Alfa class submarine

The Soviet Union/Russian Navy Project 705 was a submarine class of hunter/killer nuclear reactor vessels . The class is also known by the List of NATO reporting names for hunter-killer and experimental submarines of Alfa....
s.

Chemistry

A silver oxide

Silver(I) oxide

Silver oxide is the chemical compound with the chemical formula Ag2O. It is a fine black or dark brown powder that is used to prepare other silver compounds....
battery is a small-sized primary battery using silver oxide as the negative electrode

Electrode

An electrode is an electrical conductor used to make contact with a nonmetallic part of a Electronic circuit . The word was coined by the scientist Michael Faraday from the Greek language words elektron and hodos, a way....
(cathode

Cathode

A cathode is an electrode through which electric charge flows out of a polarized electrical device. Mnemonic: CCD .From an electrochemical point of view, positively charged ion invariably move toward the cathode and/or negatively charged ion move away from it to balance the electrons arriving from external circuitry....
), zinc

Zinc

Zinc is a metallic chemical element with the symbol Zn and atomic number 30. It is a first-row transition metal of the group 12 element of the periodic table....
as the positive electrode (anode

Anode

An anode is an electrode through which electric charge flows into a polarized electrical device. Mnemonic: ACID . Electrons flow in the opposite direction to the positive electric current....
) plus an alkaline electrolyte, usually sodium hydroxide

Sodium hydroxide

Sodium hydroxide , also known as lye, caustic soda and sodium hydrate, is a caustic metallic Base . Sodium hydroxide forms a strong alkaline solution when dissolved in a solvent such as water, however, only the hydroxide ion is basic....
(NaOH) or potassium hydroxide

Potassium hydroxide

Potassium hydroxide is the inorganic compound with the formula potassiumhydroxide. Along with sodium hydroxide, this colourless solid is a prototypical "strong base"....
(KOH). The silver

Silver

Silver is a chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal....
is reduced at the cathode from Ag(I) to Ag(s) and the zinc

Zinc

Zinc is a metallic chemical element with the symbol Zn and atomic number 30. It is a first-row transition metal of the group 12 element of the periodic table....
is oxidized from Zn to Zn(II). The chemical reaction that takes place inside the battery is the following:

Zinc is the activator in the negative electrode and corrodes in alkaline solution. When this happens, it becomes difficult to maintain the capacity of the unused battery. The zinc corrosion causes electrolysis

Electrolysis

In chemistry and manufacturing, electrolysis is a method of separating Chemical bond chemical compound by passing an electric current through them....
in the electrolyte

Electrolyte

An electrolyte is any substance containing free ions that behaves as an electrical conductor medium. Because they generally consist of ions in solution, electrolytes are also known as ionic solutions, but molten electrolytes and solid electrolytes are also possible....
, resulting in the production of hydrogen

Hydrogen

Hydrogen is the chemical element with atomic number 1. It is represented by the chemical symbol H. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly combustion and explosive Diatomic molecule gas with the molecular formula H2....
gas, a rise of inner pressure and expansion of the cell. Mercury

Mercury (element)

Natural environment

The natural environment, commonly referred to simply as the environment, is a term that encompasses all life and non-living things occurring nature on Earth or some region thereof....
.

Characteristics

Compared to other batteries, a silver oxide battery has a higher open circuit potential than a mercury battery

Mercury battery

A mercury battery is a non-rechargeable battery , a primary cell. Due to the content of Mercury , and the resulting environmental concerns, the sale of mercury batteries is banned in many countries....
, and a flatter discharge curve than a standard alkaline battery

Alkaline battery

Alkaline batteries and alkaline cells are a type of disposable battery or Rechargeable alkaline battery battery dependent upon the reaction between zinc and manganese oxide ....
.

It provides up to 40 percent more run time than lithium-ion batteries and also feature a water-based chemistry that is free from the thermal runaway and flammability problems that have plagued the lithium-ion alternatives.

History

This technology had the highest energy density

Energy density

Energy density is the amount of energy stored in a given system or region of space per unit volume, or per unit mass, depending on the context, although the latter is more formally specific energy ....
(prior to lithium technologies), and was primarily developed for aircraft use. It was the power source in all of the Apollo spacecraft: the Saturn

Saturn (rocket family)

The Saturn family of rockets were developed by a team of mostly German rocket scientists led by Wernher von Braun to launch heavy payloads to Earth orbit and beyond....
launch vehicles, command module

Apollo Command/Service Module

The Command/Service Module was a spacecraft built for NASA by North American Aviation. It was one of the two spacecraft that were utilized for the Apollo program, along with the Apollo Lunar Module, to land astronauts on the Moon....
re-entry batteries, the lunar module

Apollo Lunar Module

The Apollo Lunar Module was the Lander portion of the Apollo spacecraft built for the United States Apollo program by Grumman to achieve the transit from cislunar orbit to the surface and back....
and the lunar rover

Lunar rover

File:Apollo15LunarRover.jpgThe Lunar Roving Vehicle or lunar rover was a type of surface exploration rover used on the Moon during the Apollo program....
. (The Apollo Service Module used fuel cells as a primary power source.)

More recently, the company has introduced a new line of rechargeable silver-zinc batteries to compete with lithium-ion batteries. The claims include an energy density of 200Wh/kg, complete non-flammability, and no toxic chemicals. To offset the high price of silver, the company plans to offer a trade-in policy to recycle all of it. Intel's venture arm, Intel Capital, has provided the company with financial backing. ZPower claims that an undisclosed "major manufacturer" of laptop computers will introduce its silver-zinc battery in a new line of laptops in 2009. (likely Lenovo or Apple Inc.)

Recycling

Silver oxide batteries become hazardous when they begin to leak which generally takes a period of five years (which is their normal life) from the time they are put into use. Until recently, all silver oxide batteries contained mercury

Mercury (element)

Mercury , also called quicksilver or hydrargyrum , is a chemical element with the symbol Hg and atomic number 80. A heavy, silvery d-block metal, mercury is one of six elements that are liquid at or near room temperature and pressure....
(around 0.2%). The mercury is incorporated into the zinc anode to inhibit corrosion in the alkaline environment. Sony started producing the first silver oxide batteries without added mercury in 2004. Most jewelers and watch makers leave these batteries in an open container in their shop, which could lead to health problems for the jewelers. If they do not retain them, they usually discard them in the trash which causes many environmental problems. Once the battery is spent (dead) it needs to be properly handled and recycled by an authorized recycler according to the EPA's Sector of Waste Wise, a program that sponsors correct ways to recycle silver oxide batteries.