Apparatuses and methods of forming battery parts are disclosed herein. In one embodiment, a method of forming a battery part includes receiving a flowable material into a cavity, and reducing a volume of the cavity while a pin extending through at least a portion of the cavity remains at least generally stationary therein. The method further includes sealing the cavity by slidably engaging at least a portion of the pin with a recess in the piston proximate the end face of the piston.