Page 190 - Lindens Handbook of Batteries

CHAPTER 8

AN INTRODUCTION TO PRIMARY
BATTERIES

David Linden and Thomas B. Reddy

8.1 GENERAL CHARACTERISTICS AND APPLICATIONS OF
PRIMARY BATTERIES

The primary battery is a convenient source of power for portable electric and electronic devices,
lighting, photographic equipment, PDAs (personal digital assistants), communication equipment,
hearing aids, watches, toys, memory backup, and a wide variety of other applications, providing
freedom from utility power. Major advantages of the primary battery are that it is convenient, simple,
and easy to use, requires little, if any, maintenance, and can be sized and shaped to fit the applica-
tion. Other general advantages are good shelf life, reasonable energy and power density, reliability,
and acceptable cost.
Primary batteries have existed for over 100 years, but up to 1940, the zinc-carbon battery was
the only one in wide use. During World War II and the postwar period, significant advances were
made, not only with the zinc-carbon system, but with new and superior types of batteries. Capacity
was improved from less than 50 Wh/kg with the early zinc-carbon batteries to more than 500 Wh/kg
now obtained with lithium and zinc/air batteries. The shelf life of batteries at the time of World
War II was limited to about 1 year when stored at moderate temperatures; the shelf life of present-
day conventional batteries is from 2 to 5 years. The shelf life of the newer lithium batteries is as high
as 10 years, with a capability of storage at temperatures as high as 70°C. Low-temperature operation
has been extended from 0 to -40°C, and the power density has been improved manyfold.
Some of the advances in primary battery performance are shown graphically in Figs. 1.6 and 8.1.
Many of the significant advances were made during the 1970–90 period and were stimulated by
the concurrent development of electronic technology, new demands for portable power sources, and
support for space, military, and environmental improvement programs.
During this period, the zinc/alkaline manganese dioxide battery began to replace the zinc-carbon
or Leclanché battery as the leading primary battery, capturing the major share of the U.S. market.
Environmental concerns led to the elimination of mercury in most batteries without any impairment of
performance, but also led to the phasing out of those batteries, zinc/mercuric oxide and cadmium/mer-
curic oxide, that used mercury as the cathodic active material. Fortunately, zinc/air and lithium batter-
ies were developed that could successfully replace these “mercury” batteries in many applications. A
major accomplishment during this period was the development and marketing of a number of lithium
batteries, using metallic lithium as the anode active material. The high specific energy of these lithium
batteries, at least twice that of most conventional aqueous primary batteries, and their superior shelf
life opened up a wide range of applications—from small coin and cylindrical batteries for memory
backup and cameras to very large batteries which were used for backup power for missile silos.

8.3