A mercury battery (also called mercuric oxide battery, or mercury cell) is a non-rechargeable electrochemical 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. A Pair of AA Energizer Alkaline Cells Symbols representing a single Cell (top) and Battery (bottom), used in circuit diagrams. ... A primary cell is any kind of electrolytic cell in which the electrochemical reaction of interest is not reversible. ... General Name, Symbol, Number mercury, Hg, 80 Chemical series transition metals Group, Period, Block 12, 6, d Appearance silvery Standard atomic weight 200. ...

Sodium hydroxide or potassium hydroxide are used as an electrolyte. Sodium hydroxide cells have nearly constant voltage at low discharge currents, making them ideal for hearing aids, calculators, and electronic watches. Potassium hydroxide cells, in turn, provided constant voltage at higher currents, making them suitable for applications requiring current surges, eg. photographic cameras with flash, and watches with a backlight. Potassium hydroxide cells also have better performance at lower temperatures. Mercury cells have very long shelf life, up to 10 years. Sodium hydroxide (NaOH), also known as lye or caustic soda or sodium hydrate, is a caustic metallic base. ... The chemical compound potassium hydroxide, (KOH) sometimes known as caustic potash, potassa, potash lye, and potassium hydrate, is a metallic base. ... An electrolyte is a substance containing free ions that behaves as an electrically conductive medium. ... A hearing aid is a device used to help the hard-of-hearing hear sounds better. ... A calculator is a device for performing calculations. ... Russian Poljot Siberia model finished movement viewed through crystal back For other uses, see Watch (disambiguation). ...

Mercury batteries use either pure mercuric oxide or a mix of mercuric oxide with manganese dioxide as the cathode. The anode is made of zinc and separated from the cathode with a layer of paper or other porous material soaked with electrolyte. During discharge, zinc oxidizes to zinc oxide and mercuric oxide gets reduced to elementary mercury. Mercury batteries are very similar to silver-oxide batteries. Mercury(II) oxide, also called mercuric oxide, has a formula of HgO and a formula weight of 216. ... Manganese(IV) oxide (MnO2) is a chemical compound also known as manganese dioxide or manganese oxide. ... Diagram of a copper cathode in a Daniells cell. ... Diagram of a zinc anode in a galvanic cell. ... General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Standard atomic weight 65. ... Zinc oxide is a chemical compound with formula ZnO. It is nearly insoluble in water but soluble in acids or alkalis. ... A Silver-oxide battery, also known as a silver-zinc battery, is a primary cell (although it may be used as a secondary cell with an open circuit potential of 1. ...

Mercury batteries using mercury(II) oxide cathode have a very flat discharge curve, holding constant 1.35 V (open circuit) voltage until about last 5% of their lifetime, when their voltage drops rapidly. Mercury batteries with cathodes made of a mix of mercuric oxide and manganese dioxide have output voltage of 1.4 V and more sloped discharge curve. Mercury(II) oxide, also called mercuric oxide, has a formula of HgO and a formula weight of 216. ... Diagram of a copper cathode in a Daniells cell. ... Manganese(IV) oxide (MnO2) is a chemical compound also known as manganese dioxide or manganese oxide. ...

The ban on sale of mercury oxide batteries caused numerous problems for photographers, whose equipment frequently relied on their advantageous discharge curves and long lifetime. Alternatives used are zinc-air batteries, with similar discharge curve but much shorter lifetime (few months) and poor performance in dry climates, alkaline batteries with voltage widely varying through their lifetime, and silver-oxide batteries with higher voltage (1.55 V) and very flat discharge curve, making them possibly the best, though expensive, replacement.^[1] Zinc-air batteries, also called “zinc-air fuel cells,“ are non-rechargeable electro-chemical batteries powered by the oxidation of zinc with oxygen from the air. ... A Duracell AA alkaline battery 2 Duracell-Brand AAA Alkaline batteries Alkaline batteries are a type of power cell dependent upon the reaction between zinc and manganese dioxide (Zn/MnO2). ... A Silver-oxide battery, also known as a silver-zinc battery, is a primary cell (although it may be used as a secondary cell with an open circuit potential of 1. ...

References

1. ^ http://home.pcisys.net/~rlsnpjs/minolta/mercury.html

See also

• Watch battery