Cylindrical battery, battery pack, and electric device

Abstract

This disclosure provides a cylindrical battery, a battery pack, and an electrical device. The cylindrical battery provided by this disclosure includes a cell, a casing, and a first explosion-proof valve. The casing houses the cell and includes a first end wall, a second end wall, and a side wall extending between them. The first end wall and the side wall are integrally connected to form a transition connection. The first explosion-proof valve is connected to at least one of the first and second end walls. The first explosion-proof valve includes a weak portion, the thickness of which is less than the thickness of the end wall body. The ratio of the length a1 to the diameter a2 of the cylindrical battery is a. The thickness difference between the first end wall and the transition connection is b. The ratio of the area c1 enclosed by the weak portion to the area c2 of the end wall is c. 0.24 ≤ (a × b) / c ≤ 201.93. Accordingly, while the risk of cracking at the transition connection between the first end wall and the side wall is eliminated or significantly reduced, the risk of side wall deformation or cracking is also eliminated or significantly reduced.

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