Abstract: Provided are an end cover, an end cover assembly, a battery cell, a battery, and an electric device. The end cover includes: two through holes, running through the end cover for mounting electrode terminals; a depression, where the depression is formed by a surface of the end cover recessing in a thickness direction, and a bottom wall of the depression forms a pressure relief mechanism; and a weak portion, disposed on the pressure relief mechanism, where the pressure relief mechanism is configured to crack along the weak portion when internal pressure of the battery cell reaches a threshold; where depth of the weak portion gradually decreases on one or two sides of a perpendicular bisector of a connecting line of the two through holes in a direction leaving the perpendicular bisector.

Abstract: A pressure relief apparatus includes a pressure relief body and a plurality of score grooves. The pressure relief body includes a pressure relief portion, and the pressure relief portion has a first surface and a second surface opposite to each other in a thickness direction of the pressure relief portion. A plurality of score grooves are sequentially arranged at the pressure relief portion in a direction from the first surface to the second surface. In two adjacent score grooves in the thickness direction, a maximum width of a score groove farther away from the first surface is less than a minimum width of a score groove closer to the first surface.

Abstract: A pressure relief apparatus, a battery cell, a battery, and an electrical device are provided in embodiments of the present application. The pressure relief apparatus includes a pressure relief body and a score groove. The pressure relief body includes a pressure relief portion configured to be opened to relieve a pressure inside the battery cell when an internal pressure or temperature of the battery cell reaches a threshold. The score groove is arranged on the pressure relief body and includes a first arc-shaped groove and a second arc-shaped groove. The arc-shaped design of the first arc-shaped groove and the second arc-shaped groove makes it less likely that the pressure relief portion cannot be opened in a large area, thereby improving the safety of the battery cell.

Abstract: The application provides a method, apparatus, device and medium for detecting an internal short-circuit fault of a battery cell. The method includes obtaining electrical signal values for each of m battery cells of a battery pack, when it is in a preset condition including that a current detection is an nth detection; performing following steps for a target battery cell: calculating a first parameter of the target battery cell using the electrical signal values of the target battery cell, which characterizes a degree of fluctuation of the electrical signal values; calculating a second parameter that characterizes a degree of dispersion between the first parameter of the target battery cell and first parameters of other battery cells; and determining that an internal short-circuit fault occurs in the target battery cell, under a condition that the second parameter is greater than a threshold.

Abstract: The application provides a method, apparatus, device and medium for detecting an internal short-circuit fault of a battery cell. The method includes obtaining electrical signal values for each of m battery cells of a battery pack, when it is in a preset condition including that a current detection is an nth detection; performing following steps for a target battery cell: calculating a first parameter of the target battery cell using the electrical signal values of the target battery cell, which characterizes a degree of fluctuation of the electrical signal values; calculating a second parameter that characterizes a degree of dispersion between the first parameter of the target battery cell and first parameters of other battery cells; and determining that an internal short-circuit fault occurs in the target battery cell, under a condition that the second parameter is greater than a threshold.