Anode design for a prismatically wound LiMnO2 cell
A prismatic cell for implantable medical devices includes an elongated anode and cathode folded together to form a prismatic cell. The anode includes an anode tab which does not extend to the bottom edge of the anode, with heat-resistant tape on the opposite side of the anode, likewise not extending to the bottom edge of the anode. This provides a strip of anode material below the anode tab which acts as a current collector reducing the increase in impedance as the cell is discharged.
1 . A prismatic cell having
an elongated anode having a long axis;
an elongated cathode having a long axis;
a separator between said anode and said cathode wherein said anode and cathode are folded together separated by said separator, said cell having two long sides and two narrow sides;
an anode tab attached to a first side of said anode; and
insulation tape attached to a second side of said anode opposite said anode tab wherein a bottom edge of said tab is above a bottom edge of said anode and a bottom edge of said insulation tape is above said bottom edge of said anode.
2 . The prismatic cell claimed in claim 1 wherein said prismatic cell is folded into a spiral.
3 . The prismatic cell claimed in claim 1 wherein said prismatic cell is folded in a serpentine configuration.
4 . The prismatic cell claimed in claim 1 wherein said anode further comprises a metal wire extended along the long axis of said anode.
5 . The prismatic cell claimed in claim 1 wherein said anode is lithium.
6 . The prismatic cell claimed in claim 1 wherein said tape extends from about 0.15 to about 0.25 inches from said bottom edge of said anode.
7 . The prismatic cell claimed in claim 1 having a metal casing wherein said casing has two long sides and two narrow sides and a bottom, and said anode tab is welded to one of said long sides.