Page 211 - Lindens Handbook of Batteries

ZINC-CARBON BATTERIES—LECLANCHÉ AND ZINC CHLORIDE CELL SYSTEMS 9.5

as well as competition from the alkaline zinc-manganese battery system for heavy-drain applica-
tions, many manufacturers are no longer investing capital to improve the Leclanché or zinc-carbon
technology. The traditional Leclanché cell construction, which utilizes a starch paste separator, is
being gradually phased out and replaced by zinc chloride batteries utilizing paper separators. This
results in increased volume available for active materials and increased capacity. In spite of these
conversion efforts by manufacturers, a number of developing countries still continue the demand for
pasted Leclanché products because of their low cost. The size of that market has prevented a com-
plete conversion. It appears that this situation will continue for the near future.
During this transitional phase, the zinc-carbon batteries can be classified into two types,
Leclanché and zinc chloride. These can, in turn, be subdivided into separate general-purpose and
premium battery grades, in both pasted and paper-lined constructions.

9.3.1 Leclanché Batteries
General Purpose. Application: Intermittent low-rate discharges; low cost. The traditional, regular
battery, which is not too different from the one introduced in the late 19th century, uses zinc as the
anode, ammonium chloride (NH Cl) as the main electrolyte component along with zinc chloride, a
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starch paste separator, and natural manganese dioxide (MnO ) ore as the cathode. Batteries of this
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formulation and design are the least expensive and are recommended for general-purpose use and
when cost is more important than superior service or performance.
Industrial Heavy-Duty. Application: Intermittent medium- to heavy-rate discharges; low to mod-
erate cost. The industrial heavy-duty zinc-carbon battery generally has been converted to the zinc
chloride system. However, some types continue to include ammonium chloride and zinc chloride
(ZnCl ) as the electrolyte and synthetic electrolytic or chemical manganese dioxide (EMD or CMD)
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alone or in combination with natural ore as the cathode. Its separator may be of starch paste, but
it is typically a paste-coated paper liner type. This grade is suitable for heavy intermittent service,
industrial applications, or medium-rate continuous discharge.

9.3.2 Zinc Chloride Batteries
General Purpose. Application: Low-rate discharges both intermittent and continuous; low cost.
This battery has replaced the Leclanché general-purpose battery in all Western countries. It is a true
zinc chloride battery and possesses some of the heavy-duty characteristics of the premium type. The
electrolyte is zinc chloride; however, some manufacturers may add small amounts of ammonium
chloride. Natural manganese dioxide ore is used as the cathode. Batteries of this formulation and
design are competitive in cost to the Leclanché general-purpose batteries. They are recommended for
general-purpose use on both continuous and intermittent discharges and when cost is an important
consideration. This battery also exhibits a low leakage characteristic.

Industrial Heavy-Duty. Application: Low to intermediate continuous and intermittent heavy-
rate discharges; low to moderate cost. This battery has generally replaced the industrial Leclanché
heavy-duty battery. It is a true zinc chloride cell and possesses the heavy-duty characteristics of the
premium zinc chloride type. The cell electrolyte is zinc chloride; however, some manufacturers may
add small amounts of ammonium chloride. Natural manganese dioxide ore is used along with elec-
trolytic manganese dioxide as the cathode. These cells use paper separators coated with cross-linked
or modified starches, which enhance their stability in the electrolyte. Batteries of this formulation
and design are competitive in cost to the Leclanché heavy-duty industrial batteries. They are rec-
ommended for heavy-duty applications where cost is an important consideration. This battery also
exhibits a low leakage characteristic.
Extra/Super Heavy-Duty. Application: Medium and heavy continuous, and heavy intermittent
discharges; higher cost than other zinc chloride types. The extra/super heavy-duty type of battery