A button cell includes a housing, the housing having a cell cup with a flat bottom area, and a cell top with a flat top area, and further includes an electrode-separator assembly winding disposed within the housing, the electrode-separator assembly winding including a multi-layer assembly that is wound in a spiral shape about an axis. The multi-layer assembly includes a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. The button cell additionally includes a first output conductor between a first end face of the electrode-separator assembly winding and a first of the flat bottom area or the flat top area, and a second output conductor between a second end face of the electrode-separator assembly winding and a second of the flat bottom area or the flat top area. Furthermore, the button cell includes a first insulator and a second insulator.

A button cell includes a housing having a cell cup with a flat bottom area and having a cell top with a flat top area. The button cell also includes an electrode-separator assembly winding disposed within the housing. The electrode-separator assembly winding includes a multi-layer assembly that is wound in a spiral shape about an axis. The multi-layer assembly includes a positive electrode formed from a first current collector coated with a first electrode material, a negative electrode formed from a second current collector coated with a second electrode material, and a separator disposed between the positive electrode and the negative electrode. The button cell further includes a winding core around which the multi-layer assembly is wound. The winding core provides a contact pressure on a first metal foil output conductor in an axial direction to facilitate electrical contact between the first metal foil output conductor and the housing.

A button cell includes a housing having a cell cup with a flat bottom area and having a cell top with a flat top area. The button cell also includes an electrode-separator assembly winding disposed within the housing. The electrode-separator assembly winding includes a multi-layer assembly that is wound in a spiral shape about an axis. The multi-layer assembly includes a positive electrode formed from a first current collector coated with a first electrode material, a negative electrode formed from a second current collector coated with a second electrode material, and a separator disposed between the positive electrode and the negative electrode. The button cell further includes a winding core around which the multi-layer assembly is wound. The winding core provides a contact pressure on a first metal foil output conductor in an axial direction to facilitate electrical contact between the first metal foil output conductor and the housing.

A battery includes an electrode body having a positive electrode and a negative electrode, in which the positive electrode and the negative electrode are wound; and an exterior material that accommodates the electrode body, in which at least one of the positive electrode and the negative electrode is divided into two or more electrodes adjacent in a winding direction, the two or more of electrodes each have a current collecting lead, and the current collecting leads are electrically connected to each other at a position outside the exterior material.

A positive electrode active material includes a plurality of groups of particles. The plurality of groups of particles has a particle diameter of more than or equal to 300 nm and less than or equal to 3 μm. Each of the groups includes two or more particles. The two or more particles are each a lithium-containing complex phosphate including one or more of iron, nickel, manganese, and cobalt. The group of particles includes a first particle and a second particle each having a major diameter and a minor diameter in the upper surface when seen from a predetermined direction. The major diameters of the first and second particles are substantially parallel to each other. The major diameter of the first particle is two to six times larger than the minor diameter of the first particle and the minor diameter of the first particle is more than or equal to 20 nm and less than or equal to 130 nm.

A positive electrode active material includes a plurality of groups of particles. The plurality of groups of particles has a particle diameter of more than or equal to 300 nm and less than or equal to 3 μm. Each of the groups includes two or more particles. The two or more particles are each a lithium-containing complex phosphate including one or more of iron, nickel, manganese, and cobalt. The group of particles includes a first particle and a second particle each having a major diameter and a minor diameter in the upper surface when seen from a predetermined direction. The major diameters of the first and second particles are substantially parallel to each other. The major diameter of the first particle is two to six times larger than the minor diameter of the first particle and the minor diameter of the first particle is more than or equal to 20 nm and less than or equal to 130 nm.

A button cell includes a housing having a cell cup, the cell cup having a flat bottom area, a cell cup casing, and a bottom edge forming a transition between the flat bottom area and the cell cup casing, and a cell top, the cell top having a flat top area and a cell top casing. An electrode-separator assembly winding is disposed within the housing, the electrode-separator assembly winding including a multi-layer assembly that is wound in a spiral shape about an axis, the multi-layer assembly including a separator disposed between a positive electrode and a negative electrode, and a first output conductor. An insulator is disposed between an end face of the electrode-separator assembly winding and the first output conductor, wherein the first output conductor is welded to the first of the flat bottom area or the flat top area.

A button cell includes a housing having a cell cup, the cell cup having a flat bottom area, a cell cup casing, and a bottom edge forming a transition between the flat bottom area and the cell cup casing, and a cell top, the cell top having a flat top area and a cell top casing. An electrode-separator assembly winding is disposed within the housing, the electrode-separator assembly winding including a multi-layer assembly that is wound in a spiral shape about an axis, the multi-layer assembly including a separator disposed between a positive electrode and a negative electrode, and a first output conductor. An insulator is disposed between an end face of the electrode-separator assembly winding and the first output conductor, wherein the first output conductor is welded to the first of the flat bottom area or the flat top area.

A method for producing a button cell includes providing a cell cup, a cell top and an electrode-separator assembly winding, the electrode-separator assembly winding having a positive electrode and a negative electrode. An electrically insulating seal is applied at least to an outer portion of the cell top casing. The electrode-separator assembly winding is inserted into the cell top. The cell top is inserted into the cell cup to form a housing. A pressure is applied in a radial direction perpendicular to an axis of the electrode-separator assembly winding so as to seal the housing.

A method for producing a button cell includes providing a cell cup, a cell top and an electrode-separator assembly winding, the electrode-separator assembly winding having a positive electrode and a negative electrode. An electrically insulating seal is applied at least to an outer portion of the cell top casing. The electrode-separator assembly winding is inserted into the cell top. The cell top is inserted into the cell cup to form a housing. A pressure is applied in a radial direction perpendicular to an axis of the electrode-separator assembly winding so as to seal the housing.