I'm no expert, Bailey, but my understanding is similar to yours.
Again, drawing from AGC's published article (linked below) they say....
"size matters when it comes to flake graphite. That's because you cannot use graphite thicker than the anode paste, which is around 100 microns, because if it sticks out of the paste, it can create paths that reduce battery capacity. The principle grade used is d50 20+/- microns. But sizes as low as 10 microns are used.
The smaller the flake the shorter the path for the lithium ion to fill the graphite gallery - says Baxter. But it's difficult to spheronise very small graphite flakes; the surface area is higher, so less graphite can be incorporated without exceeding viscosity limits of the machinery"
