This sounds like a small tweak in the manufacturing process that could lead to potentially very large gains down the road. Fantastic work!
This could reduce the number of service visits to battery-powered, low-current-draw remote sensing equipment and such. In that sort of use case, it could be a big deal.
This is not going to make a meaningful difference in devices that you charge on a daily / weekly basis (cell phones, laptops, smart watches).
Additionally, there's a significant portion of "self discharge" of lithium packs that is actually the battery protection circuitry (BMS).
That's not to say this isn't a good catch; like you mention, low power devices that you want to go months between charges may benefit significantly.