The aspect not completely addressed in the Youtube movie of The Limiting Factor is that only the top and bottom of the cells are shown connected with the overall casing.
However, for better integral structural stiffness, also the individual cells can be glued to each other.
The result will be a 'honeycomb of tubes', which will be much stiffer than the above.
(However, not as stiff as a 'true' honeycomb. Bees have proven to be top engineers!
)
Calculations of stress/deformations of such a pack can be done with FEM (Finite Element Method).
The structural pack will probably present some challenges, however.
One of the potential problems ('terra incognita'): stresses in the cell casings will mean uneven deformations of the cell casings.
Maybe small, but nonetheless. How will that affect the working and durability of the batteries in the long term?
Furthermore: it will be near impossible to extract a defective cell, unless the bonding with other cell casings can be deactivated in a clever way.
So: one cell fails -> a whole new batterypack will be needed.
One more reason why the cells will have to be very durable.
A lot of technical challenges, but the outcome could provide a high payout in structural (torsional) stiffness versus weight.
Tesla has shown in the past to be up to these challenges. It will mean a car with great driving characteristics.
I am very much looking forward to the PlaidX and the new Roadster!