# US 12,181,436 B2 · Gas sensor element and gas sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,181,436 B2 - Document ID: US12181436B2 - Status: Granted - Kind: B2 - Application number: 17/356,968 - Filed: 2021-06-24 - Published: 2021-10-14 - Granted: 2024-12-31 - Earliest claimed: 2018-12-28 - Assignees: Denso Corporation - Applicants: Denso Corporation - Inventors: Chika Kuroki; Satoshi Suzuki - Web page: https://patentgrep.com/patent/US12181436B2 ## CPC - G01N 27/4071: {using sensor elements of laminated structure} - G01N 27/4067: {Means for heating or controlling the temperature of the solid electrolyte} - G01N 27/4075: {Composition or fabrication of the electrodes and coatings thereon, e.g. catalysts} - G01N 27/409: Oxygen concentration cells - G01N 27/41: Oxygen pumping cells - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract A gas sensor element includes a solid electrolyte body, a measurement electrode film, and a measured-gas intake port. The measurement electrode film includes a noble metal region, a solid electrolyte region, and a mixed region in which a noble metal and a solid electrolyte are mixed together. The measurement electrode film has a structure in which a first average thickness of the mixed region within a first region is greater than a second average thickness of the mixed region within a second region that is closer to a center of the measurement electrode film than the first region in a direction along an intake direction of a measured gas is. The first region is a region from an electrode end on the measured-gas intake port side to ¼ of an overall length of the measurement electrode film in the direction along the intake direction of the measured gas. ## Claims ### Claim 1 A gas sensor element comprising: a solid electrolyte body; a measurement electrode film that is formed on a main surface of the solid electrolyte body and exposed to a measured gas; and a measured-gas intake port into which the measured gas is introduced, wherein the measurement electrode film has a noble metal region that includes a noble metal, a solid electrolyte region that includes a solid electrolyte, and a mixed region in which the noble metal and the solid electrolyte are mixed together, and the measurement electrode film has a structure in which a first average thickness of the mixed region that is present within a first region from an electrode end on a measured-gas intake port side to ¼ of an overall length of the measurement electrode film in a direction along an intake direction of the measured gas is greater than a second average thickness of the mixed region that is present within a second region that is closer to a center of the measurement electrode film than the first region in the direction along the intake direction is. ### Claim 2 (depends on 1) The gas sensor element according to claim 1, wherein: the first average thickness of the mixed region within the first region is larger than a third average thickness of the mixed region that is present in the measurement electrode film. ### Claim 3 (depends on 2) The gas sensor element according to claim 2, wherein: the first average thickness of the mixed region within the first region is equal to or greater than 0.1 micrometers. ### Claim 4 (depends on 3) The gas sensor element according to claim 3, wherein: the third average thickness of the mixed region that is present in the measurement electrode film is equal to or less than 0.08 micrometers. ### Claim 5 (depends on 4) The gas sensor element according to claim 4, wherein: the main surface is a first main surface, the solid electrolyte body has a second main surface that is positioned on a side opposite to the first main surface, a reference electrode film that is exposed to a reference gas is formed on the second main surface, and an electrode end on a measured-gas intake port side of the reference electrode film is arranged closer to the measured-gas intake port than the electrode end on the measured-gas intake port side of the measurement electrode film is. ### Claim 6 (depends on 5) The gas sensor element according to claim 5, wherein: the gas sensor element further includes a heater that heats the gas sensor element; and the heater is configured such that a highest temperature position in a heat generation distribution in the measurement electrode film is closer to the measured-gas intake port than the center of the measurement electrode film is in the direction along the intake direction. ### Claim 7 (depends on 6) The gas sensor element according to claim 6, wherein: the gas sensor element includes a measured gas space into which the measured gas is introduced from the measured-gas intake port, a reference-gas intake port into which the reference gas is introduced, and a reference gas space into which the reference gas is introduced from the reference gas intake port; the solid electrolyte body is arranged between the measured gas space and the reference gas space, the first main surface of the solid electrolyte body faces the measured gas space, and the second main surface faces the reference gas space; and the gas sensor element has a shape that is elongated in a longitudinal direction, the measured-gas intake port is formed in a tip end in the longitudinal direction of the gas sensor element, and the reference-gas intake port is formed on a side opposite to the tip end in the longitudinal direction. ### Claim 8 (depends on 2) The gas sensor element according to claim 2, wherein: the third average thickness of the mixed region that is present in the measurement electrode film is equal to or less than 0.08 micrometers. ### Claim 9 (depends on 1) The gas sensor element according to claim 1, wherein: the first average thickness of the mixed region within the first region is equal to or greater than 0.1 micrometers. ### Claim 10 (depends on 1) The gas sensor element according to claim 1, wherein: the main surface is a first main surface, the solid electrolyte body has a second main surface that is positioned on a side opposite to the first main surface, a reference electrode film that is exposed to a reference gas is formed on the second main surface, and an electrode end on a measured-gas intake port side of the reference electrode film is arranged closer to the measured-gas intake port than the electrode end on the measured-gas intake port side of the measurement electrode film is. ### Claim 11 (depends on 10) The gas sensor element according to claim 10, wherein: the gas sensor element includes a measured gas space into which the measured gas is introduced from the measured-gas intake port, a reference-gas intake port into which the reference gas is introduced, and a reference gas space into which the reference gas is introduced from the reference gas intake port; the solid electrolyte body is arranged between the measured gas space and the reference gas space, the first main surface of the solid electrolyte body faces the measured gas space, and the second main surface faces the reference gas space; and the gas sensor element has a shape that is elongated in a longitudinal direction, the measured-gas intake port is formed in a tip end in the longitudinal direction of the gas sensor element, and the reference-gas intake port is formed on a side opposite to the tip end in the longitudinal direction. ### Claim 12 (depends on 1) The gas sensor element according to claim 1, wherein: the gas sensor element further includes a heater that heats the gas sensor element; and the heater is configured such that a highest temperature position in a heat generation distribution in the measurement electrode film is closer to the measured-gas intake port than the center of the measurement electrode film is in the direction along the intake direction. ### Claim 13 (depends on 12) The gas sensor element according to claim 12, wherein: the gas sensor element includes a measured gas space into which the measured gas is introduced from the measured-gas intake port, a reference-gas intake port into which the reference gas is introduced, and a reference gas space into which the reference gas is introduced from the reference gas intake port; the solid electrolyte body is arranged between the measured gas space and the reference gas space, the first main surface of the solid electrolyte body faces the measured gas space, and the second main surface faces the reference gas space; and the gas sensor element has a shape that is elongated in a longitudinal direction, the measured-gas intake port is formed in a tip end in the longitudinal direction of the gas sensor element, and the reference-gas intake port is formed on a side opposite to the tip end in the longitudinal direction. ### Claim 14 A gas sensor comprising: a gas sensor element comprising: a solid electrolyte body; a measurement electrode film that is formed on a main surface of the solid electrolyte body and exposed to a measured gas; and a measured-gas intake port into which the measured gas is introduced, wherein the measurement electrode film has a noble metal region that includes a noble metal, a solid electrolyte region that includes a solid electrolyte, and a mixed region in which the noble metal and the solid electrolyte are mixed together, and the measurement electrode film has a structure in which a first average thickness of the mixed region that is present within a first region from an electrode end on a measured-gas intake port side to ¼ of an overall length of the measurement electrode film in a direction along an intake direction of the measured gas is greater than a second average thickness of the mixed region that is present within a second region that is closer to a center of the measurement electrode film than the first region in the direction along the intake direction is.