Technology

The silver zinc technology has been in usage in a variety of applications since the 1940’s, with continuing improvements in its wet life, cycle life and performance. The overall cell reaction is as follows:

The silver zinc couple offers many enviable attributes unmatched by other electrochemistries: Advantages include

Excellent Energy Density
Excellent Power Density
Excellent Charge Retention
Excellent Electrochemical Efficiency
Excellent Low Temperature Performance
High Discharge Rate Capability (up to 1 A/in2)
Excellent Safety Record (benign failure)

The silver zinc electrochemistry is capable of up to 25 months and 100 cycles (100%DOD), depending upon the design and application.

The open circuit voltage of a fully charged silver zinc cell is 1.86 vdc. For a partially discharged cell, the open circuit voltage is 1.60 vdc.

Under load, the silver zinc electrochemistry is known for its flat discharge profile. A comparison of the various plateau voltages at various “C” discharge rates is shown as follows:

How does the silver zinc rechargeable battery compare to other rechargeable chemistries? In the table below are shown the various energy densities of popular battery types today:

Chemistry	Gravimetric (Wh/kg)	Volumetric (Wh/l)
Pb-Acid	30-45	60-100
Ni-Cd	40-65	70-100
Ni-H2	40-60	70-90
Ni-MH	60-80	100-140
Li-Ion	115-180	250-360
Ag-Zn	140-200	400-510

Relative to handling and usage, there are several factors which can either increase of decrease the useful life of a silver zinc battery. These are described below:

What factors increases life? These include:

Moderate Temperature Operation
Low Temperature Storage < 40 ºF
Full Charge Cut-off at Recommended Voltage
Low Rate Charge
Regular Maintenance

Those factors which can decrease life include:

High Temperature Operation
High Temperature Storage > 125 ºF
Overcharge
Cell Reversal (overdischarge)
(All of the above can be controlled by proper maintenance).