Nickel Cadmium
The Nickel Cadmium (NiCd) cell chemistry is different from NiMH cell chemistry in that the NiCd cell absorbs cadmium where the NiMH cell stores hydrogen. Cadmium is much larger and heavier than hydrogen, which leads to lower volumetric and gravimetric energy densities of the NiCd cell.
The NiCd’s cycle life and discharge voltage profile are equivalent to NiMH. Also, NiCd’s can be placed into storage at any state of charge (SOC). Nevertheless, the NiCd battery needs to be completely discharged before it is charged to avoid the occurrence of voltage depression (or memory effect). Furthermore, the primary disadvantage to the use of the NiCd chemistry is the environmental concerns and health risks associated with the use of cadmium.
- Long Cycle Life
- Good Storage Characteristics
- Rapid Charge Compatible
Table 1
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Advantages
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Disadvantages
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Typical Application
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Long cycle life
Good storage characteristics
Rapid charge compatible
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Low volumetric and gravimetric energy density
Memory effect/voltage depression
Environmental and health concerns (e.g. kidney damage, itai-itai (ouch-ouch) disease in Japan, and Mutagenic)
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Calculators, power tools, tape recorders, flashlights, medical devices (e.g., defibrillators), electric vehicles, space applications
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Typical Performance Characteristics of NiCd Batteries
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Operational Battery Voltage
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0.9 to 1.5 Volts
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Specific Energy
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30 to 40 Wh/Kg
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Energy Density
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85 to 100 W/L
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Power Density
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100 to 150 W/Kg
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Continuous Rate Capability
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Typical: 3C
High Rate: 10C
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Pulse Rate Capability
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Up to 25C
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Cycle Life at 100% DOD
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Typically 500
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Calendar Life
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3 - 5 years
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Self Discharge Rate
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25% / month
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Operable Temperature Range
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-20 °C to 60 °C
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Memory Effect
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Yes
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