DoITPoMS

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Primary batteries:

Primary batteries are not easily rechargeable, and consequently are discharged then disposed of. Many of these are “dry cells” – cells in which the electrolyte is not a liquid but a paste or similar. The cell electrochemical reactions are not easily reversible and cell is operated until the active components in the electrodes are exhausted. Generally primary batteries have a higher capacity and initial voltage than rechargeable batteries.

Applications:

  • Portable devices
  • Lighting
  • Toys
  • Memory back-up
  • Watches/clocks
  • Hearing aids
  • Radios
  • Medical implants
  • Defence related systems such as missiles

Advantages:

  • Inexpensive
  • Convenient
  • Lightweight
  • Good shelf life
  • High Energy density at low/moderate discharges

Disadvantages:

  • Can only be used once
  • Leads to large amount of waste batteries to be recycled
  • Batteries put into landfill sites have severe environmental impact
  • Life cycle energy efficiency < 2 %

 

The table below demonstrates the properties of various primary batteries:

System Nominal Cell Voltage (V) Capacity (Wh/kg) Advantages Disadvantages Applications
1.50
65
Lowest cost; variety of shapes and sizes
Low energy density; poor low-temperature performance
Torches; radios; electronic toys and games
Mg/MnO2
1.60
105
Higher capacity than C/Zn; good shelf life
High gassing on discharge; delayed voltage
Military and aircraft receiver-transmitters
1.50
95
Higher capacity than C/Zn; good low-temperature performance
Moderate cost
Personal stereos; calculators; radio; TV
Zn/HgO
1.35
105
High Energy density; flat discharge; stable voltage
Expensive; energy density only moderate
Hearing aids; pacemakers; photography; military sensors/detectors
Cd/HgO
0.90
45
Good high and low-temperature performance; good shelf life
Expensive; low energy density
1.50
130
High Energy density, good high rate performance
Expensive (but cost effective)
Watches; photography; missiles; Larger space applications
Zn/Air
1.50
290
High Energy density; long shelf life
Dependent on environment; limited power output
Watches; hearing aids; railway signals; electric fences
Li/SOCl2
3.60
300
High Energy density; long shelf life
Only low to moderate rate applications
Memory devices; standby electrical power devices
Li/SO2
3.00
280
High energy density; best low-temperature performance; long shelf life
High-cost pressurized system
Military and special industrial needs
Li/MnO2
3.00
200
High energy density; good low-temperature performance; cost effective
Small in size, only low-drain applications
Electrical medical devices; memory circuits; fusing

 


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