Storage temperature, manganese dioxide

Magnesium has been used successfully in a magnesium/manganese dioxide (Mg/MnO,) battery. This battery has two main advantages over the zinc-carbon battery, namely, twice the service life or capacity of the zinc battery of equivalent size and the ability to retain this capacity, during storage, even at elevated temperatures (Table 9.1). This excellent storability is due to a protective film that forms on the surface of the magnesium anode. 

The shelf life of the magnesium/manganese dioxide primary battery at various storage temperatures is compared with the shelf life of the zinc-carbon battery in Fig. 9.11. The magnesium battery is noted for its excellent shelf life. The battery can be stored for periods of 5 years or longer at 20°C with a total capacity loss of 10 to 20% and at temperatures as... 

FIGURE 10.18 Effect of time and storage temperature on relative discharge performance (on moderate drain) of alkaUne-manganese dioxide batteries. From Eveready Battery Engineering Book. )... 

The shelf life of fresh, unused (charged) rechargeable alkaline-manganese dioxide batteries is about the same as that of the primary batteries (20 to 25% loss after 3 to 4 years when stored at room temperature). The data for capacity losses after high-temperature storage are shown in Fig. 36.14. 

The capacity or service life of lithium-manganese dioxide cells, normalized for a 1 g and a 1 cm cell, at various temperatures and loads, is summarized in Figure 30.50. These data can be used to calculate the performance of a given cell or to select a cell of suitable size or weight for a particular application. It is to be noted that, since the actual cell performance is dependent on cell size and construction and other such factors, these data are only approximate. These cells are a relatively new type and consequently only limited storage life data are available. Projections suggest that cells will provide 85% of initial capacity after 6 years storage at 20 C. 

Field experience has shown that shelf life is an outstanding characteristic of manganese dioxide-magnesium perchlorate batteries. After 18 months storage at room temperature, magnesium batteries have yielded 90% of their initial capacity. Storage for 90 days at 55 C has shown that the battery still retains 85% of its initial capacity, and after storage at THC for 30 days the capacity retention is 85%. The shelf life of... 

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