Lots of battery holders and dispensers out there already, and this is another design.
It's a vase-mode battery holder that takes advantage of the flexibility of the plastic to keep the batteries from discharging against stray metal objects.
Tested and printed in basic PLA. PETG should also work just fine, but untested. Walls are designed to be 0.45mm. Can be printed in vase mode for quick singles or regular mode for bulk. Insert and remove the batteries by flexing the opening.