The invention provides a cylindrical
lithium battery. A
necking groove is formed in a shell in the cylindrical
lithium battery, the height H2 of the
necking groove is 0.1%-1% of the height H1 of the shell, and the depth H3 of the
necking groove in the radial direction is 5%-10% of the outer
diameter D1 of the shell; the sum of the areas of all second holes of a positive collector plate in the cylindrical
lithium battery is 0.9-1.5 times of the area of a first hole, a fusing groove is formed in a
tail body part of the positive collector plate, and the distance between the center position of the fusing groove and the end, away from a plate body part, of the
tail body part is 68-78% of the length of the
tail body part; the minimum sectional area S2 of the tail body part at the position of the fusing groove is 45%-65% of the overall sectional area S1 of the tail body part; the negative collector plate in the cylindrical
lithium battery is provided with a heightening platform with a flat surface, and the flatness of the surface of the heightening platform is 0.01-0.05 mm. By reasonably designing the necking part, the positive collector plate and the negative collector plate, the cylindrical
lithium battery disclosed by the invention is balanced in multiple aspects of
liquid injection performance, safety,
weldability and the like, and the battery performance can be improved.