The energy content only went up 5X, where volume increased by 5.5X, denoting a volumetric energy density DECREASE for the cell. Does this mean the gains in range were purely gravimetric energy density increases? They do gain in footprint because of extra cell height and no cooling channels, so they can fit more energy in a pack.
I don't know. There was a lot of stuff in that presentation that was misleading. Touting 5x energy increase in big bold letters at the beginning was kinda ridiculous since the volume was 5.5x as you pointed out. The more I think about the presentation, the less I'm blown away by it. If you're going to give details, then make it real details, not crayon level crap.
Real battery researchers spot those kinds of misleading numbers right away. Obviously the presentation was for a less technical audience. And to be fair there was indeed a LOT of good technology shown like tabless, dry electrode, silicon anode, structural cells, etc. But again, it was shown at a high level with a lot of "secret sauce" as Elon called it, not shown.
It would be nice if one of the youtubers that Elon follows were to ask him some questions, like: Why did the energy density of the cell drop? That 5x number, was it gravimetric or volumetric energy increase?
The other thing I'd like to know is how much graphite vs silicon is in their new anode. Is it all silicon now and no graphite? Have they proven long cycle life with that new anode?
BTW, you'll note there was zero talk of electrolyte improvements. More secret sauce, no doubt.