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Yeah... I'm not sure what that is. They also conflate mA and mAh a few times. It's kind of confusing.

I think that they are using the weight of lithium metal rather than the actual battery. That's the only thing that makes sense, as the specific energy of PURE LITHIUM is barely above that 10.5 Wh/g figure. The 10.5 must come from the energy drop to sulfur intercalation, which is at .4v. The 8.5 Wh/g figure comes from the reversable voltage range. It's either that or their numbers are off by 100x.




With units of Wh/g (Li metal), my impression is that it's measuring grams of pure lithium.


Yes, but its not a useful measure. Most batteries will have similar specific energy when compared by lithium directly. How effectively the lithium is used is also almost completely irrelevant to the cost, weight and size of the battery. It's just a really weird thing to measure and they don't actually specify what the grams are of- lithium or sulfur are just the only things that make sense.


The grams are specified as "g (Li metal)", so grams of lithium.


Yes, but on first read I thought that they were specifying for the battery using lithium metal as they were also talking about sodium and nonmetallic lithium. It's just so random I didn't read it correctly.


Is lithium the most expensive material in the chemistry?


I made a cursory attempt to find the answer, and I was unsuccessful. I did find this[1], though (from my alma mater).

[1] https://engineering.cmu.edu/media/press/2016/12_13_whitacre_...


That makes sense... Li is typically 4% of the weight of a Li-Ion battery, so that would align pretty well.




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