On your new battery, put a strip of Kapton high temperature adhesive tape lengthwise almost the full length of the battery.

Wrap each end of the battery one wrap of Kapton. Let 1/8" or so overhang the end of the battery.

The original battery has paper tape under, the nickle tab, over the nickle tab and the battery rim, protecting the battery from mechanical damage, so this is the purpose of the Kapton tape.

The Pono's battery compartment is snug. Too much tape could make the fit too tight but too little tape is also not advised.