Zinc-carbon batteries advantages

The advantages and disadvantages of zinc-carbon batteries, compared with other primary battery systems, are summarized in Table 8.2. A comparison of the more popular primary cell systems is given in Chap. 7. 

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. 

Alkaline manganese batteries are a direct competitor to the standard carbon-zinc (Leclanch6) battery over which, in certain applications, they enjoy advantages in performance. The primary alkaline manganese battery, which first became available in 1960, represents a major advance over the standard carbon-zinc battery and meets the growing need for a high-rate source of electiical energy. 

The performance and capacity advantages of alkaline batteries vs carbon—zinc is resulting in the continuous decline of this battery. The low cost of the carbon zinc cell is a major reason for its continued use. Thus, cost is a major consideration in the development and selection of separators for this system. 

The advantage of zinc-air cells also presents a big challenge for battery designers. Remaining open to the atmosphere renders zinc-air cells exposed to detrimental environmental conditions, especially humidity. Water in humid air can be absorbed by the basic electrolyte solution diluting it and subsequently flooding the cathode. Arid air may evaporate water from the electrolyte and dry the cathode. Both conditions lead to reduced cell performance and battery life. Carbon dioxide in the air can enter the cell, react with the basic electrolyte solution and precipitate carbonates, also decreasing performance. 

The advantages of the alkaline cell over the carbon-zinc cells are summarized below (Table 1). The main disadvantage of the alkaline cell is its higher price over the carbon-zinc battery systems. 

Advantages of alkaline Zn-Mn02 battery system compared to carbon-zinc batteries ... 

Although alkaline manganese batteries can outperform carbon—zinc batteries in any type of service, as indicated earlier, they may now show economic advantage over them at light drains, or under intermittent-duty conditions, or both. For example, with intermittent use at current drains below about 300 mA the D cell size alkaline type, while performing very well, will begin to lose its economic advantage over carbon-zinc batteries. 

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