BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:
FIG. 1 is a sectional view of a lithium ion secondary battery;
FIG. 2A is a sectional view of a lithium ion secondary battery constructed as an embodiment of the present invention;
FIG. 2B is a perspective view of a center pin constructed as an embodiment of the present invention;
FIG. 2C is a sectional view taken along the line A-A of FIG. 2B;
FIG. 3 is a sectional view of a center pin constructed as another embodiment of the present invention;
FIG. 4A is a perspective view of a center pin constructed as still another embodiment of the present invention; and
FIG. 4B is a sectional view taken along the line B-B of FIG. 4A.