Cylindrical battery

Abstract

The sealing body (17) of the battery (10) includes: an upper valve body (26) that breaks upon increasing internal pressure; and an integral cap (27) having an annular portion (27a), a cylindrical portion (27b), and a circular plate portion (27c). The annular portion (27a) is engaged with the outer periphery of the upper surface (35) of the upper valve body (26). The cylindrical portion (27b) protrudes upward from the inner end of the annular portion (27a) in the radial direction. The circular plate portion (27c) blocks the opening of the cylindrical portion (27b). A recess (40) is provided on the upper surface (35) of the upper valve body (26), and the recess (40) is included at the point where it overlaps with the annular portion (27a) in the axial direction. The battery (10) has a high-hardness component (50), which includes a receiving portion (50a) housed in the recess (40) and is harder than the upper valve body (26).

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