An electrode package includes a pouch having pouch walls forming a sealed pouch enclosure. At least one electrode is within the pouch enclosure and includes an electrode wire having one end connected to the electrode within the pouch, an intermediate portion extending through the pouch walls, and a second end outside the pouch enclosure. A sealing joint is formed at the point where the intermediate portion of the wire extends through the pouch walls. The pouch walls have a plastic layer which surrounds and contacts the intermediate portion of the wire at the sealing joint to form an air tight seal. The invention also includes a method whereby heat and pressure are applied at the sealing joint to cause the plastic layer of the pouch walls to melt and fuse around the wires to create the seal.