SK Innovation's NCM 811, by any chance?
I am guessing the volumetric density is going to be
800 Wh/L at 300 Wh/kg, due to a consistent Li-ion density of approximately
2 2/3 kg/L, and judging from the difference between the older types and upper limits of NMC 811.
(that is,
250Wh/kg & 670Wh/L and the theoretical maximum manufacturable NCM 811's with
350+ Wh/kg & 950+ Wh/L, from another source I can't find again...)
http://pushevs.com/2017/09/02/sk-innovation-start-producing-ncm-811-battery-cells-soon/
Also see the links at the bottom of that page.
I've also found some interesting consistencies:
- From wk057's post, an 18650 from the 100kWh pack has
12.4 Wh of usable energy.
-
12.4 Wh results from a
3.6 to 3.65 V nominal at
3400 to 3450 mAh recorded for Panasonic's top 18650 batteries.
- From a Panasonic datasheet, an 18650 is said to weigh
49 grams , give or take half a gram. Dividing
12.4 Wh by this number gives
253 Wh/kg.
- Increasing
12.4 Wh by the 2170's volume difference of +
46% and accounting for Straubel's "
15% more efficient" statement, that is, 12.4 x 1.46 x 1.15, gives a result of
20.8 Wh.
- A figure that got bandied around sometime ago was the "
5750 mAh" from a presentation somewhere.
- As it turns out, dividing
21 Wh /
5.75 Ah gives...
3.65V.
- Given that a 2170 cell is highly likely to have a mass of 65-70 grams by noting the difference between the masses of the 18650s and big old 26650s, circa
20 to 21 Wh at 70 to 65 grams means a specific energy range of 20/0.070 to 21/0.065 or
285 to 320 Wh/kg & therefore 760 to 850 Wh/L.
So there is my new assumption... 300 Wh/kg and probably 800 Wh/L it is.
...And I'll just leave this here as well. Would love to know if anyone could find out the source of that image halfway down the page...
Because it explicitly states that the 2170 cell by Tesla has 300 Wh/kg and costs $170 per kWh.
https://www.dnkpower.com/teslas-mass-production-21700-battery/