An energy storage device includes an electrode assembly formed by winding a negative electrode plate, a separator and the like. An innermost periphery of the negative electrode plate, the separator and the like which are wound together has a flattened shape having a pair of bent portions disposed on opposite sides in a first direction as viewed in a direction of the winding axis, and an end edge of the negative electrode plate on an innermost periphery side is disposed at one bent portion out of the pair of bent portions or a position in the vicinity of the one bent portion.

A capacitor assembly structure and a method of manufacturing the same are provided. The capacitor assembly structure includes a capacitor unit, an insulative package body, a plurality of positive composite material layers, a conductive connection layer and an electrode unit. The capacitor unit includes a plurality of capacitors each having a positive portion and a negative portion. The insulative package body partially covers the capacitors. A lateral side of the positive portion is exposed from a first lateral surface of the insulative package body. Each positive composite material layer is disposed on the first lateral surface and the lateral side so as to electrically connect to the positive portion. The conductive connection layer is electrically connected to the negative portion. The electrode unit includes a first electrode structure electrically contacting the positive composite material layer and a second electrode structure electrically contacting the conductive connection layer.

A capacitor assembly structure and a method of manufacturing the same are provided. The capacitor assembly structure includes a capacitor unit, an insulative package body, a plurality of positive composite material layers, a conductive connection layer and an electrode unit. The capacitor unit includes a plurality of capacitors each having a positive portion and a negative portion. The insulative package body partially covers the capacitors. A lateral side of the positive portion is exposed from a first lateral surface of the insulative package body. Each positive composite material layer is disposed on the first lateral surface and the lateral side so as to electrically connect to the positive portion. The conductive connection layer is electrically connected to the negative portion. The electrode unit includes a first electrode structure electrically contacting the positive composite material layer and a second electrode structure electrically contacting the conductive connection layer.

An electrode foil for an electrolytic capacitor including a metal porous portion, and a metal core portion continuous to the metal porous portion. When the metal porous portion is equally divided in three in a thickness direction of the metal porous portion into a first region, a second region, and a third region sequentially from the metal core portion side, the first region has a porosity P1, the second region has a porosity P2, and the third region has a porosity P3, satisfying P1<P2<P3.

An electrode foil having high capacitance per unit volume is provided. The electrode foil is an electrode foil for an electrolytic capacitor. The electrode foil is an electrode foil extending in a longitudinal direction and having a width direction orthogonal to the longitudinal direction, the electrode foil including an enlarged surface portion on a surface of the electrode foil, wherein a crack is formed in the enlarged surface portion in a direction oblique to the width direction.

A solid electrolytic capacitor comprising a capacitor element is provided. The capacitor element comprises a sintered porous anode body, a dielectric that overlies the anode body, and a solid electrolyte that overlies the dielectric and that includes conductive polymer particles. The anode body has an exterior surface that spans in a longitudinal direction to define a length of the anode body, wherein at least one channel is recessed into the exterior surface of the anode body. The channel is defined by opposing sidewalls that intersect at a base, wherein the channel has a width of from about 0.4 millimeters to about 3 millimeters and a depth of from about 50 micrometers to about 350 micrometers.

A solid electrolytic capacitor comprising a capacitor element is provided. The capacitor element comprises a sintered porous anode body, a dielectric that overlies the anode body, and a solid electrolyte that overlies the dielectric and that includes conductive polymer particles. The anode body has an exterior surface that spans in a longitudinal direction to define a length of the anode body, wherein at least one channel is recessed into the exterior surface of the anode body. The channel is defined by opposing sidewalls that intersect at a base, wherein the channel has a width of from about 0.4 millimeters to about 3 millimeters and a depth of from about 50 micrometers to about 350 micrometers.

A tantalum capacitor includes a capacitor body comprising a tantalum body having a tantalum wire and a molded portion; an anodic terminal connected to the tantalum wire and disposed on the first surface of the capacitor body; an anodic connection portion connected to the anodic terminal and disposed on the fifth surface of the capacitor body; a cathodic terminal connected to the tantalum body and disposed on the second surface of the capacitor body; a cathodic connection portion connected to the cathodic terminal and spaced apart from the anodic connection portion on the fifth surface of the capacitor body; and a substrate disposed on the sixth surface of the body and on which the tantalum body is mounted, wherein the anodic terminal and the cathodic terminal are electrically isolated on the substrate.

A tantalum capacitor includes a capacitor body comprising a tantalum body having a tantalum wire and a molded portion; an anodic terminal connected to the tantalum wire and disposed on the first surface of the capacitor body; an anodic connection portion connected to the anodic terminal and disposed on the fifth surface of the capacitor body; a cathodic terminal connected to the tantalum body and disposed on the second surface of the capacitor body; a cathodic connection portion connected to the cathodic terminal and spaced apart from the anodic connection portion on the fifth surface of the capacitor body; and a substrate disposed on the sixth surface of the body and on which the tantalum body is mounted, wherein the anodic terminal and the cathodic terminal are electrically isolated on the substrate.

To provide an electrolytic capacitor with improved reliability. The electrolytic capacitor including: at least one capacitor element including an anode foil having a first part including a first end, and a second part including a second end, a dielectric layer formed on at least a surface of the second part, and a cathode part covering at least part of the dielectric layer; a package body enclosing the capacitor element; and an external electrode. At least a surface of the second part has a porous portion, and at least an end face of the first end is exposed from the package body and is in contact with the external electrode.