Page 209 - Lindens Handbook of Batteries

ZINC-CARBON BATTERIES—LECLANCHÉ AND ZINC CHLORIDE CELL SYSTEMS 9.3

at the 1900 World’s Fair in Paris. These advances were instrumental in establishing industrial pro-
duction and commercialization of the “zinc-carbon dry cell” and led to the evolution of “dry-cell”
portable power.
From the early 1900s through the 1990s, the portable power industry was driven to meet the needs
of the electric and electronic industries. In the early part of the 20th century, battery-operated tele-
phones, electric doorbells, toys, lighting devices, and countless other applications placed increasing
demands on “dry battery” manufacturers. Through the middle of the century, the advent of radio broad-
casting and World War II military applications further increased that demand significantly. In the latter
part of the century, demands for an inexpensive battery to power flashlights, portable transistor radios,
electric clocks, cameras, electronic toys, and other convenience applications maintained the demand.
Zinc-carbon technology has continued to evolve. During much of the 20th century, the system was
continually improved. Manganese dioxide materials, electrolytic and chemical, with higher capacity
and substantially higher activity than the natural manganese ores, had been developed. The use of
acetylene black carbon as a substitute for graphite has not only provided a more conductive cathode
structure, but the higher absorption properties have enhanced the handling characteristics of the cath-
ode powder. Improved manufacturing techniques were implemented that resulted in the production
of an improved product at lower costs. A better understanding of the reaction mechanisms, improved
separators, and venting seal systems have all contributed to the present state of the zinc-carbon art.
A significant portion of the technology effort since the 1960s has been directed toward developing
the zinc chloride cell system. This design provided substantially improved performance on heavy-
drain applications over that of the Leclanché cell. From the 1980s to the present time, development
effort has been focused on environmental concerns, including the elimination of mercury, cadmium,
and other heavy metals from the system. The work of the past century has extended the discharge life
and storage life of the zinc-carbon battery over 400% compared to the 1910 version. 3–9
Most of zinc-carbon cell manufacturing and battery assembly is now done outside of the United
States. Manufacturers have opted to consolidate and relocate plants and equipment to achieve cost
reductions through the use of economies of scale, low-cost labor, and materials. Regional plants are
coming of age rather than local country manufacturing facilities. This has occurred because of the
improved conditions in global trade, which in many areas has reduced tariffs and duties. As a direct
result, cell prices have generally been maintained at steady levels and business opportunities for
zinc-carbon batteries have increased globally.
The advantages and disadvantages of zinc-carbon batteries, compared with other primary battery
systems, are summarized in Table 9.2. A comparison of the more popular primary cell systems is
given in Chap. 8.

TABLE 9.2 Major Advantage and Disadvantages of Leclanché and Zinc Chloride Batteries

Standard Leclanché battery
Advantages Disadvantages General comments
Low cell cost Low energy density Good shelf life if refrigerated
Low cost per watt-hour Poor low-temperature service For best capacity, the discharge should
Large variety of shapes, sizes, voltages, Poor leakage resistance under abusive be intermittent
and capacities conditions Capacity decreases as the discharge
Various formulations Low efficiency under high current drains drain increases
Wide distribution and availability Comparatively poor shelf life Steadily falling voltage is useful if early
Long tradition of reliability Voltage falls steadily with discharge warning of end of life is important
Standard zinc chloride battery
Advantages Disadvantages General comments
Higher energy density Requires excellent sealing system due to Steadily falling voltage with discharge
Better low-temperature service increased oxygen sensitivity Good shock resistance
Good leak resistance Low to medium initial cost
High efficiency under heavy discharge
loads