US 11,756,740 B2
Electrode body, electrolytic capacitor provided with electrode body, and method for producing electrode body
Kazuya Koseki, Kanagawa (JP); Kazuma Okura, Kanagawa (JP); Kazuhiro Nagahara, Tokyo (JP); and Kenji Machida, Ibaraki (JP)
Assigned to NIPPON CHEMI-CON CORPORATION
Appl. No. 17/57,545
Filed by NIPPON CHEMI-CON CORPORATION, Tokyo (JP)
PCT Filed Jun. 7, 2019, PCT No. PCT/JP2019/022741
§ 371(c)(1), (2) Date Nov. 20, 2020,
PCT Pub. No. WO2019/240041, PCT Pub. Date Dec. 19, 2019.
Claims priority of application No. 2018-111486 (JP), filed on Jun. 11, 2018.
Prior Publication US 2021/0193395 A1, Jun. 24, 2021
Int. Cl. H01G 9/042 (2006.01); H01G 9/055 (2006.01)
CPC H01G 9/0425 (2013.01) [H01G 9/042 (2013.01); H01G 9/055 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An electrode body used for a cathode of an electrolytic capacitor, comprising:
a cathode foil made of a valve acting metal, having an enlarged surface layer formed on a surface; and
a carbon layer formed on the enlarged surface layer,
wherein
an interface between the enlarged surface layer and the carbon layer has an uneven shape;
the enlarged surface layer is formed by digging a plurality of etching pits;
a diameter of the etching pit is 0.12 μm or more and 0.43 μm or less near a surface layer;
a depth of the etching pit is 1.5 μm or more and 5.0 μm or less;
in the uneven shape, a distance between both ends in a cross section obtained by cutting a convex region along a height direction is 1.5 μm or more and 8.0 μm or less; and
the uneven shape has the convex region height of 0.15 μm or more and 0.80 μm or less.