Alkaline cell

Alkaline cell Alkaline chlorination Alkaline coupling Alkakne-earth metals Alkaline earths... 

Battery electrolytes are concentrated solutions of strong electrolytes and the Debye-Huckel theory of dilute solutions is only an approximation. Typical values for the resistivity of battery electrolytes range from about 1 ohmcm for sulfuric acid [7664-93-9] H2SO4, in lead—acid batteries and for potassium hydroxide [1310-58-3] KOH, in alkaline cells to about 100 ohmcm for organic electrolytes in lithium [7439-93-2] Li, batteries. 

Cylindrical alkaline cells are 2inc—manganese dioxide cells having an alkaline electrolyte, which are constmcted in the standard cylindrical si2es, R20 "D", R14 "C", R6 "AA", R03 "AAA", as well as a few other less common si2es. They can be used in the same types of devices as ordinary Leclanchn and 2inc chloride cells. Moreover, the high level of performance makes them ideally suited for appHcations such as toys, audio devices, and cameras. 

Chemistry. The alkaline cell derives its power from the reduction of the manganese dioxide cathode and the oxidation of the zinc anode. The reactions... 

Alternatively, there are also iuhibitors that decrease the rate of hydrogen generation and thus decrease corrosion. Mercury, effective at inhibiting 2iac corrosion, has long been used as an additive to 2iac anodes. More recentiy, however, because of iacreased iaterest ia environmental issues, the amount of mercury ia alkaline cells has been reduced. 

In a cylindrical alkaline cell, the amount of electrolyte is limited and the electrolyte becomes saturated with 2incate rather early in the discharge. Thus the cell produces the 2inc oxide reaction product through most of its discharge. 

For heavy drain discharges of alkaline cells, there is no useful capacity after this point because the rate of discharge of the ZnMn204 is quite slow. But for lighter drain discharges, further reduction of the cathode is possible. The reaction mechanisms are not entirely clear, but there is some evidence for the formation of a final reaction product resembling hausmannite [1309-55-3] Mn O. ... 

Cylindrical alkaline cells are made in only a few standard si2es and have only one important chemistry. In contrast, miniature alkaline cells are made in a large number of different si2es, using many different chemical systems. Whereas the cylindrical alkaline batteries are multipurpose batteries, used for a wide variety of devices under a variety of discharge conditions, miniature alkaline batteries are highly speciali2ed, with the cathode material, separator type, and electrolyte all chosen to match the particular appHcation. 

There are many methods of fabricating the electrodes for these cell systems. The eadiest commercially successhil developments used nickel hydroxide [12054-48-7] Ni(OH)2, positive electrodes. These electrodes are commonly called nickel electrodes, disregarding the actual chemical composition. Alkaline cells using the copper oxide—2inc couple preceeded nickel batteries but the CuO system never functioned well as a secondary battery. It was, however, commercially available for many years as a primary battery (see BatterieS-PRIMARY cells). 

Alkali-zelle,/. (Elec.) alkaline cell alkali-metal (photo)cell. -zellstoff, m. alkali cellulose. Alkalizitat, /. alkalinity. 

Alkaline cells offer the highest energy density (more energy per given volume) of any zinc-manganese dioxide cell, and the manufacturers continue to improve on performance. In 1998, Duracell intro-... 

Lithium primary cells have also been introduced up to the AA-size. These voltage compatible cells have a working voltage of 1.5 V, and can deliver up to four times the energy of a comparable alkaline cell. 

Leclanche or dry cell Alkaline Cell Silver-Zinc Reuben Cell Zinc-Air Fuel Cell Lithium Iodine Lithium-Sulfur Dioxide Lithium-Thionyl Chloride Lithium-Manganese Dioxide Lithium-Carbon Monofluoride... 

Zn - Mn02 batteries [2] dominate the world s small-format battery industry. In 1995 Zn-carbon batteries (the carbon rod in the center of Leclanche cells is the reason for this name) comprised 67 percent of the world market, and the other 33% belonged to alkaline cells (Table 1). 

Alkaline batteries were introduced in the early 1960s they last two to five times longer than Zn-carbon cells on continuous discharge and command two or three times the price in the USA (far more in Europe and the East). Alkaline cells became a necessary invention and they succeeded as a result of the requirements of the electronic devices. The essential improvement was the change from ammonium chloride and/or zinc chloride electrolyte to alkaline (KOH) electrolyte, the steel can construction, the outside cathode, and the zinc powder (large surface) anode. A main low-cost feature is that they use pressed cathodes and do not need to follow "jellyroll"... 

Tabic 3. Geographic sampling of alkaline cell penetration... 

Region/Country Population Income [ 10 1 Batteries per No. of batteries Alkaline cell... 

RAM batteries are suitable for all applications served by single-use alkaline cells,... 

If it is desired to optimize RAM battery usage, the examples in Fig. 5 should be considered. A 0.62 Ah cycling at 4 Q (50 percent DOD of 1.25 Ah initial capacity) results in 80 cycles with a cumulative capacity of nearly 50 Ah. Recharging is done after each discharge. A 0.38 Ah cycling at 10 Q (25 percent DOD of 1.5 Ah initial capacity) results in over 300 cycles, with a cumulative capacity over 100 Ah. The replacement of 60 alkaline cells and about... 

Figure 23 shows discharge caves of a new type of alkaline cells, which is able to discharge at a very high rate. 

Figure 23. New japanese alkaline cells using expanded graphite and other recent improvement...

Cells of cylindrical geometry are produced mainly in four sizes D (LR-20), C (LR-14), AA (LR-6), and AAA (LR-03). The two other alkaline cells in this section (using HgO or an oxygen electrode as cathode) are almost exclusively produced as small button cells. 

In order to classify this diversity from the viewpoint of the separator, the basic requirements for separators in alkaline cells are discussed below and an attempt at structuring them accordingly is made. 

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