Nickel-Metal Hydride (NiMH) vs. Silicon-Carbon (Si-C)
Comparing 2 standards across 9 specifications. 9 key differences identified.
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.
Silicon-Carbon (Si-C) battery chemistry incorporates a porous silicon-carbon composite matrix into the anode, enabling theoretical lithium capacity up to 4,200 mAh/g (vs 372 mAh/g for pure graphite). Operating at 3.7V–3.8V nominal, commercial Si-C cells achieve gravimetric energy densities of 300–350+ Wh/kg and volumetric densities exceeding 850 Wh/L in ultra-slim smartphone and EV pouch formats.
Specification Comparison Table
9 Parameters| Parameter / Spec | ||
|---|---|---|
|
Nominal Cell Voltage
|
1.20 V | 3.70 – 3.80 V |
|
Gravimetric Energy Density
|
60 – 120 Wh/kg | 300 – 360 Wh/kg |
|
Volumetric Energy Density
|
180 – 300 Wh/L | 800 – 900 Wh/L |
|
Cycle Life (to 80% Capacity)
|
500 – 1,500 Cycles | 800 – 1,200 Cycles |
|
Thermal Runaway Threshold
|
> 250 °C | ~160 – 210 °C |
|
Operating Temperature Range
|
-20 to +50 °C | -20 to +60 °C |
|
Self-Discharge Rate
|
10–20% / Month (Standard) | < 1% / Month (LSD) | 1 – 2% / Month |
|
Primary Anode Material
|
Hydrogen-absorbing Rare Earth Alloy (AB5 or AB2 Metal Hydride) | Porous Silicon-Carbon (Si-C) Composite (10–30% Si) |
|
Primary Cathode Material
|
Nickel Oxyhydroxide (NiOOH) | High-Nickel NMC (Nickel Manganese Cobalt) / LCO |