Nickel-Cadmium (NiCd) vs. Nickel-Metal Hydride (NiMH)
Comparing 2 standards across 9 specifications. 7 key differences identified.
Nickel-Cadmium (NiCd) is a mature, exceptionally rugged alkaline secondary chemistry operating at 1.2V nominal. Renowned for sustaining massive pulse discharge currents, operating reliably in deep sub-zero temperatures (-40°C), and enduring harsh electrical abuse, NiCd remains in service for aircraft backup power, emergency lighting, and legacy industrial systems.
Nickel-Metal Hydride (NiMH) is the dominant rechargeable consumer chemistry for standard cylindrical battery formats (AA, AAA, C, D). Operating at 1.2V nominal, NiMH provides 60–120 Wh/kg specific energy, eliminates toxic cadmium, and modern Low Self-Discharge (LSD / Eneloop) formulations retain 70–85% of charge after several years of storage.
Specification Comparison Table
9 Parameters| Parameter / Spec | ||
|---|---|---|
|
Nominal Cell Voltage
|
1.20 V | 1.20 V |
|
Gravimetric Energy Density
|
45 – 65 Wh/kg | 60 – 120 Wh/kg |
|
Volumetric Energy Density
|
120 – 160 Wh/L | 180 – 300 Wh/L |
|
Cycle Life (to 80% Capacity)
|
1,000 – 2,000 Cycles | 500 – 1,500 Cycles |
|
Thermal Runaway Threshold
|
> 260 °C | > 250 °C |
|
Operating Temperature Range
|
-40 to +60 °C | -20 to +50 °C |
|
Self-Discharge Rate
|
15 – 20% / Month | 10–20% / Month (Standard) | < 1% / Month (LSD) |
|
Primary Anode Material
|
Metallic Cadmium (Cd) | Hydrogen-absorbing Rare Earth Alloy (AB5 or AB2 Metal Hydride) |
|
Primary Cathode Material
|
Nickel Oxyhydroxide (NiOOH) | Nickel Oxyhydroxide (NiOOH) |