A button cell includes a housing cup and a top separated by a seal and forms a housing with parallel flat bottom and top areas, and an electrode-separator assembly including a flat positive and negative electrode and connected by one flat separator, wherein the electrodes are aligned essentially at right angles to the flat bottom and top areas and the assembly is a spiral winding having end faces defining side surfaces of the winding facing in an axial direction relative to the flat bottom and top areas, one of the electrodes connects to the flat bottom or top area via an output conductor including a foil resting between an end face of the winding and the flat top or bottom area, and at least one insulator preventing direct mechanical and electrical contact between the end faces of the winding and the flat bottom and top areas.

A button cell includes a housing cup and a top separated by a seal and forms a housing with parallel flat bottom and top areas, and an electrode-separator assembly including a flat positive and negative electrode and connected by one flat separator, wherein the electrodes are aligned essentially at right angles to the flat bottom and top areas and the assembly is a spiral winding having end faces defining side surfaces of the winding facing in an axial direction relative to the flat bottom and top areas, one of the electrodes connects to the flat bottom or top area via an output conductor including a foil resting between an end face of the winding and the flat top or bottom area, and at least one insulator preventing direct mechanical and electrical contact between the end faces of the winding and the flat bottom and top areas.

A nonaqueous electrolyte battery with a spirally coiled electrode body (10) including a cathode (11) having a cathode active material and an anode (12) having an anode active material which are coiled through a separator (13) in a battery can (1). As the separator (13), is used a separator having a plurality of laminated microporous films made of polyolefin which have different film layer thickness and average pore size. Specially, the separator (13) has three or more layers of microporous films made of polyolefin laminated. Further, the outermost layer of the separator is made of porous polypropylene and at least one layer of inner layers is made of porous polyethylene. The total of the thickness of layers made of porous polyethylene is located within a range of 40% to 84% as thick as the thickness of the separator. Thus, the temperature of a battery can be controlled, a reliability is enhanced and a productivity and cyclic characteristics are improved.

An energy storage device including a spiral electrode group in which a first electrode plate and a second electrode plate having polarity reverse to that of the first electrode plate are spirally wound with a separator interposed therebetween, wherein the second electrode plate is opposed to an inner circumference and an outer circumference of the first electrode plate, portions of the separator are reinforced, the reinforced portions of the separator include a first reinforced portion formed between a winding-start end of the first electrode plate and the second electrode plate located on a radially outer side of the winding-start end, and a second reinforced portion formed between the winding-start end of the first electrode plate and the second electrode plate located on a radially inner side of the winding-start end, and the first reinforced portion and the second reinforced portion are arranged apart from each other.

A button cell includes a housing cup and a top separated by a seal and forms a housing with parallel flat bottom and top areas, and an electrode-separator assembly including a flat positive and negative electrode and connected by one flat separator, wherein the electrodes are aligned essentially at right angles to the flat bottom and top areas and the assembly is a spiral winding having end faces defining side surfaces of the winding facing in an axial direction relative to the flat bottom and top areas, one of the electrodes connects to the flat bottom or top area via an output conductor including a foil resting between an end face of the winding and the flat top or bottom area, and at least one insulator preventing direct mechanical and electrical contact between the end faces of the winding and the flat bottom and top areas.

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 cell cup casing and the cell top casing are radially overlapping along an overlap area that extends in an axial direction, and an interference fit is formed between the cell cup casing and the cell top casing in the overlap area.

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 cell cup casing and the cell top casing are radially overlapping along an overlap area that extends in an axial direction, and an interference fit is formed between the cell cup casing and the cell top casing in the overlap area.

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 m. 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 m. 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.