Capacitor and method of forming a capacitor

1 . A capacitor comprising:

a capacitive element arranged in a housing, wherein

the capacitive element has an anode that comprises a sintered valve metal,

a fraction of volume occupied by the anode with respect to a total volume inside the housing is 20% or higher,

at least a portion of the capacitive element is soaked with or immersed in an electrolyte, said electrolyte comprises an at least dicarboxylic acid having a pKai of 4.1 or higher, and the concentration of the at least dicarboxylic acid is 0.1 wt % or higher,

in the housing a gas dissipation element is arranged that is configured for reducing a gas pressure inside the capacitor,

wherein a contact surface of the housing comprises a surface structuring that is configured to improve a bonding between a portion of the gas dissipation element that is in contact with the contact surface and said contact surface, and

wherein the gas dissipation element is chemisorbed onto the housing, and

a portion of silicon in the gas dissipation element or in an active portion of the gas dissipation element is 5 wt % or higher.

2 . The capacitor according to claim 1 , wherein the valve metal is or comprises Al.

3 . The capacitor according to claim 1 , wherein an average thickness of the anode is at least 80 μm.

4 . A capacitor comprising:

a capacitive element arranged in a housing, wherein

in or on the housing a gas dissipation element configured for reducing a gas pressure inside the capacitor is arranged,

wherein a portion of silicon in the gas dissipation element or in an active portion of the gas dissipation element is 5 wt % or higher,

wherein the gas dissipation element is arranged in or on the housing in such a manner that a contact surface of the housing comprises a surface structuring that is configured to improve a bonding between a portion of the gas dissipation element that is in contact with the contact surface and said contact surface, and

wherein the gas dissipation element is chemisorbed onto the housing.

5 . The capacitor according to claim 4 , wherein the gas dissipation element has an active portion configured for reducing the gas pressure inside the capacitor and a passive portion that provides a mechanical connection between the housing and the active portion.

6 . The capacitor according to claim 4 , wherein an active volume of the gas dissipation element or the volume of an active portion of the gas dissipation element is 0.05 mm 3 or higher.

7 . The capacitor according to claim 5 , wherein the active portion of the gas dissipation element has a cylindrical form.

8 . The capacitor according to claim 5 , wherein the active portion of the gas dissipation element is configured to irreversibly rupture or irreversibly disconnect from the passive portion upon a pressure increase which cannot be compensated by the non-destructive pressure reduction capabilities of the gas dissipation element.

9 . The capacitor according to claim 4 , wherein at least a portion of the capacitive element is soaked with or immersed in an electrolyte, and the electrolyte comprises an organic acid having a pKa of 4.1 or higher.

10 . The capacitor according to claim 9 , wherein the organic acid is an at least dicarboxylic acid having a pKai of 4.1 or higher.

11 . The capacitor according to claim 9 , wherein the concentration of the organic acid is at least 0.1 wt %.

12 . The capacitor according to claim 9 , wherein a main component of the electrolyte is a polyol.

13 . The capacitor according to claim 4 , wherein the capacitive element has an anode that comprises a sintered valve metal.

14 . A method for producing a capacitor, comprising:

providing a housing having a through hole or first opening, wherein the housing comprises a casing and a cover,

arranging in or on the through hole or first opening a gas dissipation element that is configured to reduce a gas pressure inside the capacitor, wherein the gas dissipation element is chemisorbed onto a contact surface of the housing, and wherein the contact surface of the housing comprises a surface structuring that is configured to improve a bonding between the housing and the gas dissipation element, and

arranging a capacitive element having and anode that comprises a sintered valve metal in the casing, and

impregnating with or soaking the capacitive element in an electrolyte,

enclosing the capacitive element in the housing by placing the cover on a cover-opening in the casing.

15 . The method of claim 14 , wherein the impregnating with or soaking the capacitive element in the electrolyte is performed before the arranging the capacitive element in the housing.