Cell voltage silver zinc

Discharge. Silver—zinc cells have one of the flattest voltage curves of any practical battery system known, although there are two voltage steps caused by the two different valence states of silver oxide. 

Ag-Zn cells have exceptional high-rate capability and are very reliable. They are rated at 175 Wh/kg and 500 Wh/1. They can deliver their full capacity at essentially constant voltage in 15 min or less. Ag-Zn cells power most torpedoes used in submarines. The largest rechargeable silver-zinc batteries were used in... 

Assuming, for example, a nominal 1.5 V per silver-zinc battery at low current densities (0.01 to 0.03 A/cm ) and lower voltages at higher currents, the designer selects the number of cells for the application. The problem is increased if high current pulse loads are required... 

As with silver-zinc, silver-cadmium batteries are usually charged at constant current at the 10 to 20-h rates. The recommended cutoff voltage during charge is normally 1.6 V per cell. 

The weight and size of a silver-zinc battery or cell is less than half that of a lead-aeid or niekel-cadmium type of similar capaeity. The silver oxide-alkaline zinc (AgjO KOH Zn) primary battery is a major contribution to miniature power sourees, and is well suited for hearing-aids, instruments, photoelecti ic exposure devices, eleetronie watehes and as referenee voltage sources. 

Work on the development of silver—zinc batteries began in 1942. This battery contairrs silver oxide as the positive electrode and zinc as the negative electrode and has an alkaline electrolyte. This combination results in what is, for alkaline batteries, a very high constant discharge voltage of approximately 1.8 or 1.5 V/cell respective to the two-step voltage discharge characteristic of silver—zinc batteries. 

The extremely low internal resistance of silver-zinc batteries permits discharges at rates as high as 30 times the ampere hour capacity rating, and its flat voltage characteristic enables highest operational efficiency and dependability. Cells have been built with capacity ranging from 0.1 A h to 20000 Ah. 

Figure 30.2 Senrice time-voltage data for silver-zinc cells current drain at 1.55V, 13kn, 0.12mA, (a)WS12, 83mAh to 9 V on 13 000 2 at 20°C (b) WS14, 200 mA h, to 0.9 V on 10 000 7 at 20°C (Courtesy of Union Carbide)...

Figure 30.3 U nion Carbide Eveready silver-zinc cell vellage-discharge curves estimated hours of sennoe at 35°C againstcbsed-drcuit voltage at stated starting drains and loads and on a 24h/day schedule (Courtesy of Union Carbide)...

Figure 31.12 shows typical voltage characteristics for high-rate and low-rate Eagle Picher silver—zinc cells. 

Figure 52.4 Typical discharge curves for a Duracell silver-zinc 10L125 (lEC designation SR41) 1.5 V cell, 38 mAh to 0.9 V on 30000 n at 20° C hours of ser/ice versus voltage (Courtesyof Duracell)...

Because no solution species is involved in the cell reaction, the quantity of electrolyte is very small and the electrodes can be maintained very close together. The cell voltage is 1.8 V, and its storage capacity is six times greater than that of a lead-acid battery of the same size. These characteristics make batteries, such as the silver-zinc cell, useful in button batteries. These... 

Use thermodynamic data from Appendix D to calculate a theoretical voltage of the silver-zinc button cell described on page 893. 

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