Page 193 - Lindens Handbook of Batteries

8.6 PRIMARY BATTERIES

Zinc-Carbon Battery. The Leclanché or zinc-carbon dry cell battery has existed for over 100 years
and had been the most widely used of all the primary batteries because of its low cost, relatively good
performance, and ready availability. Cells and batteries of many sizes and characteristics have been
manufactured to meet the requirements of a wide variety of applications. Significant improvements
in capacity and shelf life were made with this battery system in the period between 1945 and 1965
through the use of new materials (such as chemical and electrolytic manganese dioxide and zinc
chloride electrolyte) and cell designs (such as the paper-lined cell). The low cost of the Leclanché
battery is a major attraction, but it has lost most of its market share, except in the developing coun-
tries, because of the newer primary batteries with superior performance characteristics, particularly
alkaline manganese dioxide.

Zinc/Alkaline/Manganese Dioxide Battery. In the past two decades, an increasing portion of the
primary battery market has shifted to the Zn/alkaline/MnO battery. This system has become the
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battery of choice because of its superior performance at higher current drains and low temperatures
and its better shelf life. While more expensive than the Leclanché battery on a unit basis, it is more
cost-effective for those applications requiring the high-rate or low-temperature capability, where the
alkaline battery can outperform the Leclanché battery by a factor of 2 to 10. In addition, because of
the advantageous shelf life of the alkaline cell, it is often selected for applications in which the bat-
tery is used intermittently and exposed to uncontrolled storage conditions (such as consumer flash-
lights and smoke alarms), but must perform dependably when required. Most recent advances have
been in the design of batteries, providing improved high-rate performance for use in digital cameras
and other consumer electronics requiring this high power capability. Competition in the marketplace
has also driven down the cost significantly.

Zinc/Mercuric Oxide Battery. The zinc/mercuric oxide battery was another important zinc anode
primary system. This battery was developed during World War II for military communication appli-
cations because of its good shelf life and high volumetric energy density. In the postwar period, it
was used in small button, flat, or cylindrical configurations as the power source in electronic watches,
calculators, hearing aids, photographic equipment, and similar applications requiring a reliable
long-life miniature power source. The use of the mercuric oxide battery in consumer application has
ended due mainly to environmental problems associated with mercury and with its replacement by
other battery systems, such as the zinc/air and lithium batteries, which have superior performance
for many applications.

Cadmium/Mercuric Oxide Battery. The substitution of cadmium for the zinc anode (the cad-
mium/mercuric oxide cell) results in a lower-voltage but very stable system, with a shelf life of up
to 10 years as well as performance at high and low temperatures. Because of the lower voltage,
the watthour capacity of this battery is about 60% of the zinc/mercuric oxide battery capacity.
Again, because of the hazardous characteristics of mercury and cadmium, the use of this battery
is limited.

Zinc/Silver Oxide Battery. The primary zinc/silver oxide battery is similar in design to the small
zinc/mercuric oxide button cell, but it has a higher specific energy and performs better at low tem-
peratures. These characteristics make this battery system desirable for use in hearing aids, calcula-
tors, and electronic watches. However, because of its high cost and the development of other battery
systems, the use of this battery system as a primary battery has been limited mainly to small button
battery applications where the higher cost is justified. Larger cells continue to be employed for
military applications.

Zinc/Air Battery. The zinc/air battery system is noted for its high energy density, but it had
been formerly used only in large, low-power batteries for signaling and navigational-aid applica-
tions. With the development of enhanced air electrodes, the high-rate capability of the system was