Mechanical force on Lithium cells

Hi everyone,

I've got a question regarding how much force one could apply to a cylindrical lithium cell (LiFePo4 in this case).
My plan was to build blocks of 32700 cells and clamp them together (plus to minus to get series connections).
However, this would mean that quite a lot of force would be exerted on the cells (longitudinal).
Would this be an issue? I could imagine it isn't ideal, especially for the plus side. When the positive or negative terminal is bent inward due to the force, could it even deform the jelly roll inside?
The force would especially be great when the battery is upright, because there is also the gravitational force of all the blocks on the bottom one, that force could easily reach 20N(2kg/4lbs) per cell.
So what are your thoughts? Is it ok to put a 20N force on a 32700 cel? Is there a clearance between the terminals and the jelly roll?
I tried applying force, nothing much happens and the terminals don't seem to deform much, but maybe it isn't advisable over the long term?

I'd love to hear your thoughts!

I just thought of a possible mitigation method, one could design the cell holders so that the cells are supported on the edges (so not in the middle of the terminals, that way all the force is on the cylinder on the outside, which shouldn't pose any issue

I think the cells are pretty strong in that direction.

Some manufacturers data would be useful, I'm working on a modular weldless pack at the mo and guestimating terminal loads at about 1.5kg, would also like a clamping load on the cells but don't want to risk going too high with either.

I assume you intend the series connections to be just pressure with no welding.
My suggestion is to spot weld a nickel strip to the cells then fold them into each other with a rubber washer between them. I would worry about the weight and vibration mashing the positive terminals along with the possibility of dust and grit getting in between creating high resistance hot spots.

Not to be negative, but pretty much each design I've read about on here that uses mechanical compression developed problems, usually from thermal expansion and contraction making the cells get loose over time, or corrosion developing between the cell ends. The few successful ones were really carefully constructed, and used Poron foam, or some other guaranteed to stay springy material, and occasional checking, so not a build it and forget it setup.

That being said, Zero Motorcycles used to do what you're writing about, with cardboard sleeves to help keep crud out of the butted cells, and big rubber bands around the whole thing.