Well, I can't find anything close to what's in the picture of the stack, or anything based on the numbers. The batteries I see listed for the i3 doesn't look like those above.
However, I do remember watching a video awhile back where they guy took apart a battery that looked similar to this. Even though there are 2 terminals on the outside, there is a bms on this inside of each battery. I don't recall the arrangement of the cells. In his video they were 18650, or maybe the 26650 (I think that's the right #).
How long will they be available? You think you could buy one now, take a look at it, then buy the rest later? Or is it a grab all or nothing kind of deal?
But what I can gather, is they are made by Samsung.
Update:
Here's a video that shows the packs. At the starting point you see the pack partially taken apart. Then later on, they take it further apart.
1M23s you can see how they are wired up internally. And at 1m55s, you get an overview shot of the packs in the holder with their caps on. These look like what you have pictured above.
So based on that, the cells are individual units made of an aluminum shell with 2 terminals and there are 12 cells per pack. I don't know what each cell/pack voltage is.
And there's the full assembly of the packs to the carriage:
