The pdf also has a picture of it where you could possibly reverse Engineer the dimensions based on the other things in the picture. Looks very flat like an iPad battery
As understand it the battery is 26 Ah and looks to be the size of my 20 mAh powerpack at home.
It seems From the video they don't look much bigger than a cellphone.
That was previously announced and CES and was described as "can be any shape and any size and any voltage within a reason".