Cell voltage alkaline manganese

The alkaline manganese dioxide cell is most widely available either as standard sized cylindrical cells with capacities ranging from 0.6 to 22 Ah or as button cells. Batteries having a wide variety of capacities and voltages are also readily available. These are all interchangeable with Leclanche and zinc chloride cells. 

Fig. 3.19 Cell voltage of an alkaline manganese cell as a function of the degree of reduction of Mn02...

Fig. 4. 25 Comparison of discharge curves at ambient temperature of voltage-compatible lithium-copper oxide button cells and conventional aqueous cells (a) lithium-copper oxide (b) alkaline manganese (c) zinc-silver oxide. Load = 75 k i...

Fig. A 1.2 (a) Pulse charge and OCV sensing of a RENEWAL rechargeable alkaline manganese cell, (b) Typical current and voltage profiles during charging of an AA sized RENEWAL rechargeable alkaline manganese cell using the pulse taper charge method. (By permission of Rayovac.)...

The cell voltage is 1.5 V. The modem type is the alkaline manganese battery but the classical cell is still on the market. 

FIGURE 36.11 Comparison of 20°C performance of rechargeable zinc/alkaline /manganese dioxide D-size battery (curve 1) to output of four AA-cells connected in parallel (in D-size can) to 0.9 V end-voltage (curve 2). (Courtesy of Battery... 

Alkaline manganese batteries perform similarly to carbon-zinc batteries in that the service hours delivered are greater when the cut-off voltage is lower. The cut-off voltage should be made as low as possible so that the high energy density of the cell can be used. 

Figure 6.1 Voltage discharge characteristics of an alkaline manganese battery (D cell) discharged continuously (Courtesy of Union Carbide)...

This cell has an operating load voltage of 1.5 V. It has been seen as a high capacity cell to outperform the alkaline manganese dioxide system and also as a cheaper replacement for silver cells. 

The characteristics summarized in Table 9.18 confirm the superiority in performance obtained over conventional alkaline manganese and dioxide cells. Thus service life is about doubled, running voltages are higher and stay constant over a longer period. 

This is typified by the curves shown in Figure 30.1 for alkaline manganese dioxide 1.5 V dry cells in which cell voltage is plotted against hours of service obtained from the cell when it is operated at a particular standard temperature (usually 20°C). Obviously such curves must be prepared when the cell is under a defined standard ohmic load. The alkaline manganese dioxide cell has a voltage of 1.5V/cell. If, as occurs in this example, it is used in an application requiring 1,25 V and the ohmic load is 150 2 then the current drain is... 

Fig ure 30.6 Service time-voltage data for primary alkaline manganese dioxide cells, current drains at 1.25 V (Courtesy of Union... 

The basic characteristics of sealed alkaline manganese dioxide rechargeable cells when using voltage-limited taper current charging are given in Table 46.1 (based on a 6 h charge period). 

Small lithium batteries are commonly used in small, portable electronic devices such as watches, thermometers, calculators, etc., as backup batteries in computers and communication equipment, and in remote-control car locks. They are available in many shapes and sizes, with the common variety being a 3-volt coin -type manganese battery, 20 mm in diameter and 1.6-4 mm thick. The heavy electrical demands of many of these devices make lithium batteries a particularly attractive option. In particular, lithium batteries can easily support the brief and heavy current demands of devices such as digital cameras. They also maintain a higher voltage for a longer period than alkaline cells. 

In alkaline Mn02-Zn systems the same electrochemically active materials, manganese dioxide and zinc, are used as in Leclanche cells. The only difference to the latter system is the cathode sleeve construction and the highly conductive KOH electrolyte (7 M 0.55 (Ocm)-l) as already mentioned. The anode is formed of zinc powder instead of a zinc can. Electrolytic manganese dioxide is used for the cathode material. Due to its low polarization and high voltage characteristic it performs far better than chemically produced manganese dioxide or natural ore. 

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