Patent ID: 8048252

Claim:
A method, comprising: positioning a bottom and top polymeric separator sheet on a working surface, with a substantially planar battery anode disposed therebetween; positioning a cutting and welding tool that is conductive against the top polymeric sheet, the cutting and welding tool having an elongate surface facing the top polymeric sheet, with a conductive protrusion extending away from the elongate surface, the protrusion at least partially defined by a laser cut and extending toward the top polymeric sheet and along the elongate surface so that it extends around the substantially planar battery anode, the elongate surface shaped for positioning the protrusion offset from and outside of a perimeter of the substantially planar battery anode; applying a pressure and an electrical current to the cutting and welding tool such that top and bottom polymeric separator sheets are welded into a bag along a path between the protrusion and the substantially planar battery anode, with the weld comprising a seal to resist ionic transfer through electrolyte, and such that the bag is excised from the top and bottom separator sheets along a path defined by the protrusion, with the substantially planar battery anode disposed in the bag; stacking the substantially planar battery anode and at least one cathode into a battery stack; and disposing the battery stack into a battery case having at least one feedthrough, with a first terminal connected to the battery stack through the at least one feedthrough, and with the battery case filled with an electrolyte.