Electrochemical energy storage cell having the features a. the energy storage cell has a cylindrical housing which encloses an interior and has a top side and an underside and a circumferential housing casing (50; 70) in between, b. the housing casing (50; 70) has an inner housing lateral surface which delimits the interior to the outside, c. a wound composite body shaped in a hollow cylindrical manner is arranged in the interior and has a helical structure comprising at least two electrode strips helically wound around a winding axis and at least one separator strip arranged between the electrode strips, d. the electrode strips each comprise a strip-like current collector having an active material coating on both sides, e. the wound composite body shaped in a hollow cylindrical manner comprises two terminal end faces, a circumferential outer composite body lateral surface and a circumferential inner composite body lateral surface, f. the inner composite body lateral surface defines an axially oriented cavity in the centre of the wound composite body, and g. a winding core (10; 20; 30) having a substantially cylindrical or hollow cylindrical shape is arranged in the axially oriented cavity and has an outer circumferential surface which rests flat on the inner composite body lateral surface, and the characterizing features h. the winding core (10; 20; 30) has a local deviation (11; 21; 31) from the cylindrical or hollow cylindrical shape in at least one region of the outer circumferential surface, i. the helical structure of the wound composite body comprises at least one local irregularity in at least one region in which one of the wound electrode strips ends and/or there is a sudden change in the thickness of one of the electrode strips, and j. the at least one region of the outer circumferential surface of the winding core (10; 20; 30) in which the local deviation (11; 21; 31) from the cylindrical or hollow cylindrical shape occurs is spatially assigned to a local irregularity of the wound composite body. a. the energy storage cell has a cylindrical housing which encloses an interior and has a top side and an underside and a circumferential housing casing (50; 70) in between, b. the housing casing (50; 70) has an inner housing lateral surface which delimits the interior to the outside, c. a wound composite body shaped in a hollow cylindrical manner is arranged in the interior and has a helical structure comprising at least two electrode strips helically wound around a winding axis and at least one separator strip arranged between the electrode strips, d. the electrode strips each comprise a strip-like current collector having an active material coating on both sides, e. the wound composite body shaped in a hollow cylindrical manner comprises two terminal end faces, a circumferential outer composite body lateral surface and a circumferential inner composite body lateral surface, f. the inner composite body lateral surface defines an axially oriented cavity in the centre of the wound composite body, and g. a winding core (10; 20; 30) having a substantially cylindrical or hollow cylindrical shape is arranged in the axially oriented cavity and has an outer circumferential surface which rests flat on the inner composite body lateral surface, and the characterizing features h. the winding core (10; 20; 30) has a local deviation (11; 21; 31) from the cylindrical or hollow cylindrical shape in at least one region of the outer circumferential surface, i. the helical structure of the wound composite body comprises at least one local irregularity in at least one region in which one of the wound electrode strips ends and/or there is a sudden change in the thickness of one of the electrode strips, and j. the at least one region of the outer circumferential surface of the winding core (10; 20; 30) in which the local deviation (11; 21; 31) from the cylindrical or hollow cylindrical shape occurs is spatially assigned to a local irregularity of the wound composite body.