Patent ID: 6884541

Claim:
A lithium secondary battery, comprising: a cylindrical battery case provided with electrode caps at both end portions; an electrode body contained in the battery case and including a positive electrode, a negative electrode, and a separator, the positive electrode and the negative electrode being wound or laminated through the separator; and an elastic body disposed between said battery case and at least one of said electrode caps with a portion where said battery case contacts said elastic body being brought into press-contact to form a caulked portion to seal said battery case, wherein R body (mm) is a diameter of a body part of said battery case and R top (mm) is a diameter of said caulked portion, and R body and R top fulfill a relationship of R body >R top , and wherein a difference between said R body (mm) and said R top (mm) is ΔR(mm), and ΔR fulfills a relationship of ΔR≦5(mm).