I came across acculon energy recently and saw that they are a US-based manufacturer who appear to be manufacturing their own in-house Li-ion and Na-ion cells, and providing datasheets for their packs.
They have datasheets for the 24 V and 48 V Li-ion and Na-ion packs:
Kudos to them for providing public-facing datasheets, in my experience this historically is uncommon for commercial entities in this space.
Looking at the datasheets, we can quickly get pack level energy density metrics, which I’ve been curious about for these systems. There doesn’t seem to be cycle life info, however.
| Length (mm) | Width (mm) | Height (mm) | Energy (kWh) | Energy density (Wh/L) | |
|---|---|---|---|---|---|
| 24 V Na-ion | 315 | 245 | 158 | 1.73 | 142 |
| 48 V Na-ion | 630 | 170 | 157 | 2.88 | 171 |
| 24 V Li-ion | 315 | 245 | 158 | 2.3 | 189 |
| 48 V Li-ion | 630 | 170 | 157 | 3.8 | 226 |
Both chemistries gain about 20-21% in energy density going from 24 V to 48 V, likely because of a higher volume of active cell volume to packaging/power electronics, busbars, etc.
Both pack voltages gain about 32-33% in energy density going from Na-ion to Li-ion. I’d wager the Li-ion has better cycle life, but that’s just a hot take.
This is nice to have as a comparison point for relatively state-of-the art intercalation battery chemistries, both the incumbent lithium and the up-and-comer sodium.