Lithium Polymer (LiPo / LCO) vs. Nickel-Metal Hydride (NiMH)
Comparing 2 standards across 9 specifications. 9 key differences identified.
Lithium Polymer (LiPo), commonly based on Lithium Cobalt Oxide (LiCoO2 / LCO), packages electrode stacks inside flexible multi-layer aluminum-laminate pouch cells rather than rigid metal cans. Operating at 3.7V–3.85V nominal (with High-Voltage LiHv variants reaching 4.35V–4.45V cutoff), LiPo offers unmatched peak discharge rates (up to 50C–100C continuous) for drones, RC modeling, and ultra-thin mobile hardware.
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
|
3.70 – 3.85 V | 1.20 V |
|
Gravimetric Energy Density
|
200 – 250 Wh/kg | 60 – 120 Wh/kg |
|
Volumetric Energy Density
|
500 – 650 Wh/L | 180 – 300 Wh/L |
|
Cycle Life (to 80% Capacity)
|
300 – 600 Cycles | 500 – 1,500 Cycles |
|
Thermal Runaway Threshold
|
~150 °C | > 250 °C |
|
Operating Temperature Range
|
-10 to +60 °C | -20 to +50 °C |
|
Self-Discharge Rate
|
3 – 5% / Month | 10–20% / Month (Standard) | < 1% / Month (LSD) |
|
Primary Anode Material
|
Graphite | Hydrogen-absorbing Rare Earth Alloy (AB5 or AB2 Metal Hydride) |
|
Primary Cathode Material
|
Lithium Cobalt Oxide (LiCoO2 / LCO) | Nickel Oxyhydroxide (NiOOH) |