Zinc carbon cell

In most cylindrical carbon—zinc cells, the zinc anode also serves as the container for the cell. The zinc can is made by drawing or extmsion. Mercury [7439-97-6J has traditionally been incorporated in the cell to improve the corrosion resistance of the anode, but the industry is in the process of removing this material because of environmental concerns. Corrosion prevention is especially important in cylindrical cells because of the tendency toward pitting of the zinc can which leads to perforation and electrolyte leakage. Other cell types, such as flat cells, do not suffer as much from this problem. 

Table 1. Specific Energies and Energy Densities of Carbon-Zinc Cells ...

It is estimated that over 14 billion alkaline Zn-Mn02 cells and 30 billion carbon-zinc cells were made worldwide in 2003. This compares to the about 500 million lead acid automotive batteries that were made in the same period. 

Bath towels (terry), number produced from one bale of cotton, 8 133t Bathtub failure rate, 26 988 Batik printing, 9 219 Batteries, 3 407-434. See also Alkaline cells Carbon-zinc cells Lead-acid batteries Lithium cells Primary batteries Secondary batteries chromium application, 6 565 cobalt applications, 7 247... 

Primary batteries, 3 434—469. See also Alkaline primary cells Batteries Carbon-zinc cells Lithium primary cells Secondary batteries defined, 3 409... 

As the paste separator is relatively thick compared with the paper liner, about 10% or more manganese dioxide can be accommodated in a paper-lined cell, resulting in a proportional increase in capacity. The pasted separator carbon—zinc cells were phased out more then a decade ago. All the cells made since then are paper-lined constructions. 

The performance and capacity advantages of alkaline batteries vs carbon—zinc is resulting in the continuous decline of this battery. The low cost of the carbon zinc cell is a major reason for its continued use. Thus, cost is a major consideration in the development and selection of separators for this system. 

Performance. Carbon-zinc cells perform best under conditions of intermittent use, and many standardized tests have been devised that are appropriate to such applications as light and heavy flashlight usage, radios, cassettes, and motors (toys). The most frequently used tests are American National Standards Institute (ANSI) tests. The tests are earned out at constant resistance and the results reported in minutes or hours of service. Figure 1 shows typical results under a light load for different size cells. 

Carbon-zinc is the generic term for the Leclanche and zinc chloride system. Carbon-zinc cells provide an economical source of electrical energy for low drain applications. The service life depends strongly on the discharge rate, the operating schedule and the cutoff voltage, as well as temperature and storage conditions. 

Carbon-zinc cells are distinguished by the composition of the electrolyte. The Leclanche cell has an aqueous ammonium chloride-zinc chloride electrolyte. The higher performance zinc chloride cell mainly has zinc chloride electrolyte and may contain a small amount of ammonium chloride. Cells are available in cylindrical and flat plate constructions, as well as combinations of cells for higher voltage applications. Approximately 30 billion carbon-zinc cells are manufactured annually. 

FIGURE 10.3 Construction of the carbon-zinc cells. The zinc chloride and Leclanche have the same construction except for the seal. The zinc chloride has a plastic-compression seal while the Leclanche has a poured hot bituminous seal instead of the plastic-compression seal shown. (Courtesy of Eveready Battery Co., St Louis, MO. With permission.)... 

The zinc chloride cell is a high performance version of the carbon-zinc cell. As its name implies, the zinc chloride cell uses a ZnCl2 electrolyte, along with synthetic or electrolytic Mn02 (EMD). The cell reaction is given in Equation 10.2. 

Production lines typically operate at upwards of 500 cells/min or more. The alkaline cell has higher energy storage, longer shelf life, and lower internal resistance than either of the two carbon-zinc cells. The alkaline cells are also produced in coin/button cell configuration as shown in Figure 10.7. 

Fig. 1 Typical discharge curves of D size alkaline and carbon-zinc cells at high rate (500mA). (From Ref. l) (View this art in color at www.dekker.com.)...

Fig. 1. Cutaway view of (a) a "D"-size pasted Leclanchii cell, and (b) a "D"-size paper-lined carbon-zinc cell (1).

However, the reaction with water can be made to be extremely slow. Because the alkaline electrolyte is corrosive toward human tissue as well as toward the materials in devices, it is more important to have a good seal toward preventing electrolyte leakage in an alkaline battery than in a carbon—zinc cell. The formation of a good seal is, however, incompatible with the formation of a noncondensable gas like hydrogen. 

The market outside of the United States reflects the historical dominance of carbon—zinc cells. For example, in Japan nearly half of all sales are carbon—zinc cells, about 33% are alkaline, and about 17% are lithium. The high proportion of lithium cells relative to U.S. sales reflects the important photographic market in Japan. Western European sales are similar to those in Japan, and Third World sales are almost totally dominated by carbon —zinc... 

Carbon Zinc Cell Battery - A cell produces electric energy by the galvanic oxidation of carbon commonly used in household appliances. 

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