Batteries mercury cells

Another important primary battery is the mercury cell. It usually comes in very small sizes and is used in hearing aids, watches, cameras, and some calculators. The anode of this cell is a zinc-mercury amalgam the reacting species is zinc. The cathode is a plate made up of mercury(II) oxide, HgO. The electrolyte is a paste containing HgO and sodium or potassium hydroxide. The electrode reactions are... 

Two common types of button batteries both use a zinc container, which acts as the anode, and an inert stainless steel cathode, as shown in Figure 11.11 on the next page. In the mercury button battery, the alkaline electrolyte paste contains mercury(II) oxide, HgO. In the silver button battery, the electrolyte paste contains silver oxide, Ag20. The batteries have similar voltages about 1.3 V for the mercury cell, and about 1.6 V for the silver cell. 

Beryllium connections and contacts are employed for switchgear and relays. Beryllium oxide is used as substrata for electronic circuits. Cadmium is used in television and fluorescent light phosphors. Cadmium, nickel and mercury are employed in batteries such as "nicad" cells and mercury cells. Mercury is used in fluorescent lamps, electrical switches, and outdoor lamps, as well as instruments for measuring pressure, temperature, and density. Selenium is employed as a photoreceptor in copying machines, and as a semiconductor in rectifiers. Lead applications include lead add storage batteries, a component in color television glass, and, in its oxide form, use as a dielectric material. 

Ebner cell — This was a battery consisting of a platinized lead plate and a bottom electrode of a mercury pool with pieces of zinc. The electrolyte is dilute sulfuric acid. See also - Tyer battery, - Daniell cell, -> zinc, - Zn2+/Zn electrodes, Zn2+/Zn(Hg) electrodes,... 

Other types of dry cell batteries include the silver cell, which has a Zn anode. Its cathode uses Ag20 as the oxidizing agent in a basic environment. Mercury cells, often used in calculators, also have a Zn anode. The cathode uses HgO as the oxidizing agent in a basic medium (see Fig. 11.15). 

The zinc-carhon, alkaline-zinc, and mercury cells are classified as primary batteries. Primary batteries produce electric energy by means of redox reactions that are not easily reversed. 

From a preliminary screening of importation data from the governmental central statistics office, it was observed that mercury was imported as mercury quicksilver and mercury colloidal suspension. Imported goods that contained mercury were mercury vapour lamps, TV camera tubes, clinical thennometers, batteries (button cell), fluorescent lamps and electrical switches. Mercury could also be present in coal that is imported to be used for power generation and other consumer products (e.g. bleaching creams). 

Both cells are manufactured as small button-sized batteries. The mercury cell is used in calculators (Figure 21.15). Because of its very steady output, the silver cell is used in watches, cameras, heart pacemakers, and hearing aids. Their major disadvantages are toxicity of discarded mercury and high cost of silver cells. 

Based on this notice, the member companies of the Battery Association of Japan (formerly Dry Cells Association of Japan) made efforts to eliminate mercury in dry cells. As a result, the use of mercury was harmed in April 1991 for manganese cells and in January 1992 for alkaline cells. Furthermore, the production of mercury cells was stopped at the end of 1995, replacing them with zinc-air cells. 

Primary cells. These are constructed of high-energy materials which react chemically and produce electrical power. The cell reaction is not reversible, and when the materials are consumed the device must be discarded. Typical examples of the primary cell are the ordinary flashlight battery (the LeClanche cell), and the zinc-mercury cells used in cameras, clocks, hearing aids, watches, and other familiar articles. 

The metal is widely used in laboratory work for making thermometers, barometers, diffusion pumps, and many other instruments. It is used in making mercury-vapor lamps and advertising signs, and is used in mercury switches and other electronic apparatus. Other uses are in making pesticides, mercury cells for caustic soda and chlorine production, dental preparations, antifouling paint, batteries, and catalysts. 

The Dry Cell Battery. The Mercury Battery. The Lead Storage Battery. The Lithium-Ion Battery. Fuel Cells... 

Other types of useful batteries include the silver cell, which has a Zn anode and a cathode that uses Ag20 as the oxidizing agent in a basic environment. Mercury cells. 

Conventional unintemiptible power supply (UPS) systems employ engine generators and/or batteries as their main sources to provide electric power for critical functions or loads when the normal supply, i.e. utility power, is not available [7], A typical UPS system consists of rechargeable batteries such as sealed lead-acid or nickel cadmium (Ni-Cd). However, these batteries contain toxic heavy metals such as cadmium, mercury, and lead that may cause serious environmental problems if they are discarded without special care [7], Further, unlike batteries, fuel cells provide continuous power for as long as reactants are supplied. This feature is especially useful whenever the duration of the power outage is uncertain. 

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