Alkaline manganese dioxide zinc cell

Chemistry of the Alkaline Manganese Dioxide Zinc Cell... 

The capacity of single-use alkaline zinc-air cells is twice that of manganese dioxide-zinc cells. They cost less than silver oxide-Zn batteries or Li batteries. The best example of consumer usage is the hearing-aid button cell. In sealed condition it can be... 

K. Kordesch, J. Daniel-Ivad, Ch. Faistauer, High power rechargeable alkaline manganese dioxide-zinc batteries, 182nd Meeting of the Electrochem. Soc., Toronto, Oct., 1992, Extended Abstract 92-2, p. 18-18 (6 AA-bundle battery replacement of single D-cell). 

ALKALINE MANGANESE DIOXIDE - ZINC BATTERIES PRIMARY AND RECHARGEABLE CELLS WITH AND WITHOUT MERCURY... 

At the moment there are no accepted standards available for RAM cells. They have to be subjected to standard tests for primary alkaline manganese dioxide zinc (PAM) cells. Table 7... 

Alkaline manganese dioxide - zinc batteries. Primary and rechargeable cells with and without mercury by W. Taucher and K. Kordesch... 

Primary alkaline manganese dioxide - zinc batteries (PAM cells)... 

The design of a AA-size alkaline manganese dioxide cell is shown in Fig. 1 (Sec. 3.1). Primary and secondary alkaline batteries are constructed in the same way and can be manufactured on essentially the same machinery. The separator material, electrode formulation, and the Mn02 Zn balance are different. Rechargeable cells are zinc-limited to prevent a discharge beyond the first electron-equivalent of the MnOz reduction. The electrolyte is 7-9 mol L KOH. The electrode reactions are ... 

The problem of low specific surface (which, however, has a beneficial effect on the corrosion rate) cannot be solved so easily. This was one important reason for the development of the alkaline Mn02 / zinc cell known as "alkaline" or "PAM" (primary alkaline manganese dioxide). 

The alkaline manganese dioxide cell is most widely available either as standard sized cylindrical cells with capacities ranging from 0.6 to 22 Ah or as button cells. Batteries having a wide variety of capacities and voltages are also readily available. These are all interchangeable with Leclanche and zinc chloride cells. 

Alkaline manganese dioxide batteries have been around since 1959. They are usually known as alkaline batteries. They are a variation of Leclanche s cells. They use an electrolyte produced manganese dioxide as cathode (to improve its purity and increase the capacity of the cell), powdered zinc as anode (to provide a larger surface area for the reaction), and a highly... 

Alkaline Primary Cells, Fig. 8 Capacity loss on storage of various miniature alkaline cell systems compared to carbon-zinc and lithium-manganese dioxide cells. The lithium-based cells have significantly better storage characteristics compared to alkaline and carbon-zinc cells... 

For example, two designs are used in cylindrical cells. One design known as the bobbin construction, is typical for zinc-carbon and alkaline-manganese dioxide cells. Here the electrodes are shaped into two concentric cylinders (Fig. 3.21a). This design maximizes the amount of active material that can be placed into the cylindrical can, but at the expense of surface area for the electrochemical reaction. 

Miniature button-type batteries, using the same zinc/alkaline-manganese dioxide chemistry as cylindrical cells, compete with other miniature battery systems such as mercuric oxide, silver oxide, and zinc/air. Table 10.2 shows the major advantages and disadvantages of miniature alkaline-manganese dioxide batteries in comparison to other miniature batteries. 

The more familiar types of primary alkaline systems are the zinc/manganese dioxide, zinc/ mercuric oxide, and zinc/silver oxide batteries. These, typically, use potassium or sodium hydroxides, in concentrations from 25 to 40% hy weight, as the electrolyte, which functions primarily as an ionic conductor and is not consumed in the discharge process. In simple form, the overall discharge reaction for these metal oxide cells can be stated as... 

Zinc/Manganese Dioxide Batteries. Several of the conventional primary battery systems have been manufactured as rechargeable batteries, but the only one currently being manufactured is the cylindrical cell using the zinc/alkaline-manganese dioxide chemistry. Its major advantage is a higher capacity than the conventional secondary batteries and a lower initial cost, but its cycle life and rate capability are limited. 

FIGURE 36.10 First cycle discharge characteristics of rechargeable zinc/alkaline/manganese dioxide AAA-size cells discharged continuously at different constant resistance loads at 20°C. Curve 1 - 10 11. 110 mA (approx.) curve 2 - 5.1 H. 190 mA (approx.) curve 3 - 3.9 H. 260 mA (approx.). (Courtesy of Battery Technologies Inc.)... 

FIGURE 36.11 Comparison of 20°C performance of rechargeable zinc/alkaline /manganese dioxide D-size battery (curve 1) to output of four AA-cells connected in parallel (in D-size can) to 0.9 V end-voltage (curve 2). (Courtesy of Battery... 

---