A tantalum powder, a tantalum powder compact, a tantalum powder sintered body, a tantalum anode, an electrolytic capacitor and a preparation method for tantalum powder. The tantalum powder contains boron element, and the tantalum powder has a specific surface area of greater than or equal to 4 m.sup.2/g; the ratio of the boron content of the tantalum powder to the specific surface area of the tantalum powder is 2˜16; the boron content is measured in weight ppm, and the specific surface area is measured in m.sup.2/g; Powder that can pass through a ρ-mesh screen in the tantalum powder accounts for over 85% of the total weight of the tantalum powder, where ρ=150˜170; and the tantalum powder with high CV has a low leakage current and dielectric loss, and good moldability.

A tantalum powder, a tantalum powder compact, a tantalum powder sintered body, a tantalum anode, an electrolytic capacitor and a preparation method for tantalum powder. The tantalum powder contains boron element, and the tantalum powder has a specific surface area of greater than or equal to 4 m.sup.2/g; the ratio of the boron content of the tantalum powder to the specific surface area of the tantalum powder is 2˜16; the boron content is measured in weight ppm, and the specific surface area is measured in m.sup.2/g; Powder that can pass through a ρ-mesh screen in the tantalum powder accounts for over 85% of the total weight of the tantalum powder, where ρ=150˜170; and the tantalum powder with high CV has a low leakage current and dielectric loss, and good moldability.

An electrolytic capacitor including: an element stack including a plurality of capacitor elements; a package body sealing the element stack; and a first and second external electrode. Each of the capacitor elements includes a first end at which the anode body is exposed, and a second end covered with the cathode section, with at least an end surface of the first end exposed from the package body. The capacitor elements include a first capacitor element in which the first end faces a first surface of the package body, and a second capacitor element in which the first end faces a second surface different from the first surface of the package body. The first and second capacitor elements stacked alternately. The first end of the first capacitor element and the first end of the second capacitor element are electrically connected to the first external electrode and the second external electrode, respectively.

An electrolytic capacitor including: an element stack including a plurality of capacitor elements; a package body sealing the element stack; and a first and second external electrode. Each of the capacitor elements includes a first end at which the anode body is exposed, and a second end covered with the cathode section, with at least an end surface of the first end exposed from the package body. The capacitor elements include a first capacitor element in which the first end faces a first surface of the package body, and a second capacitor element in which the first end faces a second surface different from the first surface of the package body. The first and second capacitor elements stacked alternately. The first end of the first capacitor element and the first end of the second capacitor element are electrically connected to the first external electrode and the second external electrode, respectively.

A cathode and an electrolytic capacitor including the cathode which can suppress production of hydrogen gas are provided. The cathode of the electrolytic capacitor includes cathode foil formed of valve action metal and a conductive layer formed on a surface of the cathode foil. A natural immersion potential of the cathode foil when immersed in an electrolyte solution is at a higher side than a natural immersion potential of reference cathode foil formed of the valve action metal with purity of 99.9%.

A cathode and an electrolytic capacitor including the cathode which can suppress production of hydrogen gas are provided. The cathode of the electrolytic capacitor includes cathode foil formed of valve action metal and a conductive layer formed on a surface of the cathode foil. A natural immersion potential of the cathode foil when immersed in an electrolyte solution is at a higher side than a natural immersion potential of reference cathode foil formed of the valve action metal with purity of 99.9%.

A lamellar transition metal sulfide composition having layers of an amorphous transition metal sulfide with cations interspersed between the layers is described. Also described are methods of synthesizing the lamellar transition metal sulfides and the use of the lamellar transition metal sulfides in electrodes, e.g., in metal-ion batteries, metal-ion/sulfur batteries, and capacitors.

A lamellar transition metal sulfide composition having layers of an amorphous transition metal sulfide with cations interspersed between the layers is described. Also described are methods of synthesizing the lamellar transition metal sulfides and the use of the lamellar transition metal sulfides in electrodes, e.g., in metal-ion batteries, metal-ion/sulfur batteries, and capacitors.

An electrolytic capacitor includes a capacitor element. The capacitor element includes an electrode group including an anode body, a cathode body, a separator, and an electrolyte layer. The anode body and the cathode body each has a foil shape. The anode body has a dielectric layer on a surface of the anode body. The electrolyte layer is in contact with the anode body, the cathode body, and the separator. The electrolyte layer contains a conductive polymer and a hydroxyl group-containing compound having a melting point of 50° C. or higher. The hydroxyl group-containing compound is at least one compound selected from the group consisting of a sugar and a polyhydric alcohol. The hydroxyl group-containing compound is unevenly distributed more in a peripheral portion of the capacitor element than in a central portion of the capacitor element.

An electrolytic capacitor includes a capacitor element. The capacitor element includes an electrode group including an anode body, a cathode body, a separator, and an electrolyte layer. The anode body and the cathode body each has a foil shape. The anode body has a dielectric layer on a surface of the anode body. The electrolyte layer is in contact with the anode body, the cathode body, and the separator. The electrolyte layer contains a conductive polymer and a hydroxyl group-containing compound having a melting point of 50° C. or higher. The hydroxyl group-containing compound is at least one compound selected from the group consisting of a sugar and a polyhydric alcohol. The hydroxyl group-containing compound is unevenly distributed more in a peripheral portion of the capacitor element than in a central portion of the capacitor element.