Alkaline (Zn-MnO2) vs. Nickel-Metal Hydride (NiMH)
Comparing 2 standards across 9 specifications. 9 key differences identified.
Alkaline (Zinc-Manganese Dioxide) is the worldwide standard primary (non-rechargeable) chemistry for consumer electronic cells (AA, AAA, C, D, 9V). Operating at 1.5V nominal, alkaline batteries utilize a potassium hydroxide (KOH) alkaline electrolyte, offering 100–140 Wh/kg energy density, a 5-to-10 year shelf life, and low environmental toxicity.
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
|
1.50 V | 1.20 V |
|
Gravimetric Energy Density
|
100 – 140 Wh/kg | 60 – 120 Wh/kg |
|
Volumetric Energy Density
|
250 – 350 Wh/L | 180 – 300 Wh/L |
|
Cycle Life (to 80% Capacity)
|
Single Use (Primary Non-Rechargeable) | 500 – 1,500 Cycles |
|
Thermal Runaway Threshold
|
> 200 °C | > 250 °C |
|
Operating Temperature Range
|
-18 to +55 °C | -20 to +50 °C |
|
Self-Discharge Rate
|
< 0.2% / Month (< 2% / Year) | 10–20% / Month (Standard) | < 1% / Month (LSD) |
|
Primary Anode Material
|
Zinc Powder (Zn) in Gel suspension | Hydrogen-absorbing Rare Earth Alloy (AB5 or AB2 Metal Hydride) |
|
Primary Cathode Material
|
Manganese Dioxide (MnO2) with Graphite conductive matrix | Nickel Oxyhydroxide (NiOOH) |