Battery Cell Types

There are many general types of electrochemical cells, the variation includes galvanic cells, electrolytic cells, fuel cells and flow cells. 

A wet cell battery has a liquid electrolyte. It is also called as flooded cell, since the liquid covers all internal parts. Wet cells were a precursor to dry cells and are commonly used as a tool for electrochemistry. A particular type of wet cell known as a concentration cell is important in imderstanding corrosion. Wet cells may be primary or secondary cells. Some other primary wet cells are the Leclanche cell. Grove cell, Bunsen cell, chromic acid cell, etc. Wet cells are used in automobile batteries and telecommunication. 

A dry cell has the electrolyte immobilized as a paste, with only enough moisture 

While a dry cell s electrolyte is not truly completely free of moisture and must contain some moisture to fimction, it has the advantage of containing no sloshing liquid and consequently making it highly suitable for small portable electric devices. 

A common dry cell battery is the zinc-carbon battery, using dry Leclanche cell, with a nominal voltage of 1.5 volts. 

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Figure 10. Charge-discharge cycle characteristics of an Ni-Cd battery (cell type 1200SC).

Charge-discharge capacity/mAh Figure 20. Charge-discharge characteristics of an Ni—MH battery (cell type AA). 

Figure 21. General charging characteristics of an Ni-MH battery (cell type 4/3A).

Numerous types of batteries are available. A comparison of batteries by cell type is shown in Table 17-1. Rechargeable batteries emit hydrogen to the atmosphere, and hence must be installed such that hydrogen does not accumulate to create an explosion hazard. Ventilation should be provided for battery compartments. 

Table 17-1 (Conrinued) Comparison of Batteries by Cell Type...

Although one of the most common storage batteries is called the nickel/cadmium system ( NiCad ), correctly written (-)Cd/KOH/NiO(OH)(+), cadmium is not usually applied as a metal to form a battery anode. The same can be said with regard to the silver/cadmium [(-) Cd / KOH / AgO (+)] and the MerCad battery [(-)Cd/KOH/HgO(+)]. The metallic negative in these cases may be formed starting with cadmium hydroxide, incorporated in the pore system of a sintered nickel plate or pressed upon a nickel-plated steel current collector (pocket plates), which is subsequently converted to cadmium metal by electrochemical reduction inside the cell (type AB2C2). This operation is done by the customers when they start the application of these (storage)... 

The development of a rechargeable polymer battery is being pursued worldwide. Its attraction lies in the specific weight of polymers, which is considerably lower than that of ordinary inorganic materials, as well as potential environmental benefits. In principle there are three different types of battery. The active polymer electrode can be used either as cathode (cell types 1, 2), or as anode (cell type 3), or as both cathode and anode (cell type 4) (Fig. 14). As the most common polymer materials are usually only oxidizable, recent research has concentrated on developing cells with a polymer cathode and a metal anode. 

Fig. 14. Cell types for a polymer battery with active polymer anode, cathode or both respectively...

However, under these conditions, the energy density is lower than with the (CH> ), electrode, whereas, on the other hand, the coulombic efficiencies attain values of 98 %. In some cases PA in its n-doped form has also been used as battery anode (cell type 3) 190,191,241) -j-jjg discharging reaction in a cell with a TiS2 cathode is as follows ... 

There have been several reports of all-plastic batteries with PA-electrodes (cell type 4) -249,2S2,253) observcd cell potentials lie between 3.4 and 2.5 V, the short circuit current was 50 mA cm down to 12 mA cm . The overall discharge reaction is ... 

Lead batteries are the storage batteries most widely used at present. This is readily explained by their low price, high reliability, and good performance. Their cycle life is a few hundred charge-discharge cycles, and for some cell types, even more than 1000 cycles. 

In Fig. 17 we have presented the current-voltage and the power characteristics of 12-cells battery from the cells type ZV300. It must be reminded that, when the zinc anode in the primary zinc-air cells is discharged, the cell is out of operation. By this, the air electrodes, which in principle can operate for a long time, are lost. In order to avoid this inconvenience, mechanically rechargeable zinc-air cells were developed [14]. The essential feature of the mechanically rechargeable zinc-air cell is that the air electrodes are used many times. 

Those rare-earth AB -type hydrides were quickly utilized in rechargeable nickel metal hydride batteries where electrochemical hydrogen charging and discharging take place at ambient temperature. Such electrochemical hydrogen storage is reversible, when the negative hydride electrode (anode) is combined with the positive Ni electrode (cathode) in the battery cell.. 

The battery separator currently used by most flooded cell type lead-acid battery manufacturers are of the microporous PE type. It was invented in the late 1960s by W. R. Grace Co. The term... 

Direct methanol fuel cell technology is relatively new compared to that of fuel cells powered by pure hydrogen, and research and development are roughly 34 years behind that of other fuel cell types. Nonetheless, the DMFC appears to be the most promising as a battery replacement for portable applications such cellular phones and laptop computers, and a number of manufacturers are already introducing commercial versions of these applications. 

Primary alkaline cells use sodium hydroxide or potassium hydroxide as tlie electrolyte. They can be made using a variety of chemistries and physical constructions. The alkaline cells of the 1990s are mostly of the limited electrolyte, dry cell type. Most primary alkaline cells are made sing zinc as the anode material a variety of cathode materials can be used. Primary alkaline cells are commonly divided into tW o classes, based on type of construction the larger, cylindrically shaped batteries, and the miniature, button-type cells. Cylindrical alkaline batteries are mainly produced using zinc-manganese dioxide chemistry, although some cylindrical zinc-mercury oxide cells are made. 

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