Alkaline-Manganese Dioxide Batteries

Performance. Alkaline manganese-dioxide batteries have relatively high energy density, as can be seen from Table 2. This results in part from the use of highly pure materials, formed into electrodes of near optimum density. Moreover, the cells are able to function well with a rather small amount of electrolyte. The result is a cell having relatively high capacity at a fairly reasonable cost. 

The chemistry is the same as for alkaline manganese—dioxide batteries. The constmction features are typical of the other miniature alkaline batteries. 

The initial voltage of an alkaline-manganese dioxide battery is about 1,5 V. Alkaline-manganese batteries use a concentrated alkaline aqueous solution (typically in the range of 30-45 % potassium hydroxide) for electrolyte. In this concentrated electrolyte, the zinc electrode reaction proceeds, but if the concentration of the alkaline solution is low, then the zinc tends to passivate. 

Mn02 is used for the same purpose as the cathode active material in lithium-manganese dioxide (Li - Mn02) batteries it has been used for a long time in zinc-carbon and alkaline-manganese dioxide batteries, which are aqueous-electrolyte systems. 

Compared with the Leclanche batteries, alkaline manganese dioxide batteries offer better performance at high discharge currents and lower temperatures and a better shelf life. They are more expensive than Leclanche batteries, but their cost per unit of energy is competitive and resources of raw materials are sufficient for mass production of these batteries. 

A battery-operated radio uses an AA-size alkaline manganese dioxide battery. If the radio drains 16 mA current at average voltage of 1.2 V for 10,140 min from the battery and the battery dies completely, calculate (a) the total energy stored in the AA battery and (b) the load resistance of the radio in ohms, (c) If the same battery is used in an audio cassette player that uses 120 mA/hr, how long will this battery last (Bhardwaj)... 

Alkaline manganese dioxide batteries have been around since 1959. They are usually known as alkaline batteries. They are a variation of Leclanche s cells. They use an electrolyte produced manganese dioxide as cathode (to improve its purity and increase the capacity of the cell), powdered zinc as anode (to provide a larger surface area for the reaction), and a highly... 

Alkaline manganese dioxide batteries are produced in cylindrical and button shapes. Their energy density at 20 °C is 125 and 38 Wh kg-1 for cylindrical and button shapes, respectively (see Table 2). Their nominal voltage is 1.5 V, which is comparable with other battery technologies (see Table 2). 

In March 1991 the European Community has adopted the following directive on batteries and accumulators containing dangerous substances alkaline manganese dioxide batteries... 

Recent emphasis on the performance of the primary alkaline manganese dioxide battery has been directed toward improving its high-rate performance to meet the requirements of the new digital cameras and other portable electronics. The new high-rate (Ultra or Premium) battery was first sold in 2000 and already commands about 25% of the market. 

FIGURE 3.15 Discharge characteristics of a 9-volt battery subjected to a 100 ms pulse (smoke detector pulse tests) (a) zinc-carbon battery (b) and (c) zinc/alkaline/ manganese dioxide battery. 

Increases in the energy density of primary hatteries has tapered off during the past decade as the existing battery systems have matured and the development of new higher energy batteries is limited by the lack of new and/or untried battery materials and chemistries. Nevertheless, advances have been made in other important performance characteristics, such as power density, shelf life and safety. Examples of these recent developments are the high power zinc/alkaline/manganese dioxide batteries for portable consumer electronics, the improvement of the zinc/air battery and the introduction of new lithium batteries. 

TABLE 8.10 ANSI Standards for Zinc-Carbon and Alkaline-Manganese Dioxide Batteries... 

Zinc-carbon batteries Alkaline-manganese dioxide batteries... 

Miniature button-type batteries, using the same zinc/alkaline-manganese dioxide chemistry as cylindrical cells, compete with other miniature battery systems such as mercuric oxide, silver oxide, and zinc/air. Table 10.2 shows the major advantages and disadvantages of miniature alkaline-manganese dioxide batteries in comparison to other miniature batteries. 

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