Abstract The discharge capacity of zinc–carbon cells
(Leclanche cell) is limited by the performance of the
cathode material (MnO2) and physical properties of carbon
powder added to MnO2
. Acetylene black, Vulcan XC 72,
Black Pearls 2000, and a carbon composite (consisting of
50% acetylene black and 50% Black Pearls 2000®) were
evaluated as cathode additives in test cells and were
compared. The study indicated that cathode mixture with
Black Pearls 2000®showed improvement in performance
than acetylene black, the most commonly used carbon in
commercial zinc–carbon cells. The performance of the test
cells was found to have a correlation with the physical
properties of the carbons used.
KeywordsZinc–carbon cell.
Leclanche cell.
Dry cell.
Acetylene black.Black pearls 2000®.Composite carbon
Introduction
Over 50 years, the zinc–carbon cell or Leclanche cell, or
most popularly known as“dry cell” is the widely used
primary battery because of its ability to power-up a wide
range of industrial and domestic/consumer electronic
gadgets and cost affordability, in turn, due to its well-established manufacturing technology and unassailable
reliability in performance. The cell consists of a composite
of manganese dioxide and carbon powder as positive
electrode or cathode, high pure zinc metal as the negative
electrode or anode, and a solution of ammonium chloride
and/or zinc chloride solution as the electrolyte.
The“general-purpose”Leclanche cell uses a mixture of
ammonium chloride and zinc chloride, whereas in heavy-duty cells, zinc chloride (15–40 %) is used as an electrolyte
[1]. The chemical processes occurring in Leclanche cells
are very complicated, since the reaction is dependent on
type and concentration of the electrolyte used, temperature
of operation, and electrochemical factors like the discharge
rate, depth of discharge, etc. The overall cell reaction for
cells using ammonium chloride electrolyte and zinc
chloride electrolyte may be represented by the following
equations: