Cell Gravimetric Energy Density

Cell Gravimetric Energy Density with the units Wh/kg is a key cell metric. The optimum metric is a high Wh/kg. Hence:

  • High nominal voltage
  • High Ah capacity
  • Low mass

Perhaps the simplest of the battery metrics as the capacity of the cell is fairly easy to measure and the mass is just a set of scales.

The only note of caution is the discharge rate at which the cell Ah capacity has been measured. For automotive C/5 to C/3 is quite representative for a range test. However, for a phone or laptop C/10 is perhaps closer. Most cell capacities are quoted by manufacturers at C/10.

  • 325 Wh/kg Lithium Sulphur (ALISE 2018)
  • 271 Wh/kg Panasonic NCR2170‑M
  • 263 Wh/kg LG Chem M50 21700
  • 260 Wh/kg Panasonic NCA 21700 (Tesla Model 3 2019)
  • 241 Wh/kg Murata 18650VTC6 (Formula E 2019-21)
  • 240 Wh/kg Panasonic NCA 1
  • 169 Wh/kg XALT 53Ah HE NMC (Formula E 2014-18)
  • 160 Wh/kg Lithium Iron Phosphate battery
  • 100-150 Wh/kg Sodium Ion battery
  • 70–100 Wh/kg Nickel Metal Hydride (NiMH) battery
  • 90 Wh/kg Sodium Nickel Chloride (Zebra) battery
  • 80 Wh/kg Sony first ever production lithium ion cell (1991)
  • 50-75 Wh/kg Nickel Cadmium (NiCd) battery
  • 35-45 Wh/kg Lead Acid battery

We will gradually add more values to this list. If there is a burning omission please contact us (Nigel)

cell energy density roadmap

Cell Energy Density Roadmaps

Wh/kg is a key metric that we look at when comparing cells. Looking at production values and adding roadmaps gives you an interesting view as to the future. Is 900Wh/kg credible when production cells have taken 30 years to move from 80Wh/kg to 300Wh/kg?

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