Lithium Iron Phosphate (LFP) vs. Nickel-Metal Hydride (NiMH)
Comparing 2 standards across 9 specifications. 9 key differences identified.
Lithium Iron Phosphate (LiFePO4 / LFP) is a cobalt-free, nickel-free lithium-ion chemistry operating at 3.2V nominal with an extraordinarily stable olivine crystal structure. LFP delivers industry-leading cycle life (3,000–6,000+ cycles) and unmatched thermal runaway tolerance (>270°C), making it the gold standard for grid energy storage (ESS), marine power, and standard-range electric vehicles.
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
|
3.20 V | 1.20 V |
|
Gravimetric Energy Density
|
140 – 180 Wh/kg | 60 – 120 Wh/kg |
|
Volumetric Energy Density
|
320 – 420 Wh/L | 180 – 300 Wh/L |
|
Cycle Life (to 80% Capacity)
|
3,000 – 6,000+ Cycles | 500 – 1,500 Cycles |
|
Thermal Runaway Threshold
|
> 270 °C | > 250 °C |
|
Operating Temperature Range
|
-20 to +65 °C | -20 to +50 °C |
|
Self-Discharge Rate
|
< 1.5% / Month | 10–20% / Month (Standard) | < 1% / Month (LSD) |
|
Primary Anode Material
|
Graphite / Carbon | Hydrogen-absorbing Rare Earth Alloy (AB5 or AB2 Metal Hydride) |
|
Primary Cathode Material
|
Lithium Iron Phosphate (LiFePO4) | Nickel Oxyhydroxide (NiOOH) |