An electrochemical cell has a cylindrically-shaped casing tube with at least first and second lithium sheets swaged onto its inner surface. The first lithium sheet has respective spaced apart first right and left edges, and the second lithium sheet has spaced apart second right and left edges. The first and second right edges and the first and second left edges of the swaged first and second lithium sheets are adjacent to but spaced apart from each other by about 0.5° to about 1° about the inner circumference of the cylindrically-shaped casing tube. A novel process for swaging the first and second lithium sheets onto the inner surface of the casing tube is also described.