JPH033180B2 - - Google Patents
Info
- Publication number
- JPH033180B2 JPH033180B2 JP57040523A JP4052382A JPH033180B2 JP H033180 B2 JPH033180 B2 JP H033180B2 JP 57040523 A JP57040523 A JP 57040523A JP 4052382 A JP4052382 A JP 4052382A JP H033180 B2 JPH033180 B2 JP H033180B2
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- oxygen
- layer
- solid electrolyte
- cathode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 229910052760 oxygen Inorganic materials 0.000 claims description 43
- 239000001301 oxygen Substances 0.000 claims description 43
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 37
- 229910052751 metal Inorganic materials 0.000 claims description 12
- 239000002184 metal Substances 0.000 claims description 12
- 239000007784 solid electrolyte Substances 0.000 claims description 12
- 229910052709 silver Inorganic materials 0.000 claims description 9
- 229910045601 alloy Inorganic materials 0.000 claims description 7
- 239000000956 alloy Substances 0.000 claims description 7
- 238000000034 method Methods 0.000 claims description 7
- 229910052763 palladium Inorganic materials 0.000 claims description 7
- 229910052697 platinum Inorganic materials 0.000 claims description 7
- 229910052741 iridium Inorganic materials 0.000 claims description 6
- 229910052703 rhodium Inorganic materials 0.000 claims description 6
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 5
- 239000004332 silver Substances 0.000 claims description 5
- 238000004544 sputter deposition Methods 0.000 claims description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 11
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 10
- 239000012212 insulator Substances 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 7
- 239000007789 gas Substances 0.000 description 7
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 7
- 150000002739 metals Chemical class 0.000 description 6
- -1 oxygen ion Chemical class 0.000 description 6
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 5
- 239000011148 porous material Substances 0.000 description 5
- 239000010948 rhodium Substances 0.000 description 5
- 238000009792 diffusion process Methods 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 229910052596 spinel Inorganic materials 0.000 description 2
- 239000011029 spinel Substances 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 229910015902 Bi 2 O 3 Inorganic materials 0.000 description 1
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- QDOXWKRWXJOMAK-UHFFFAOYSA-N dichromium trioxide Chemical compound O=[Cr]O[Cr]=O QDOXWKRWXJOMAK-UHFFFAOYSA-N 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 229910052839 forsterite Inorganic materials 0.000 description 1
- 229910000040 hydrogen fluoride Inorganic materials 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 229920002120 photoresistant polymer Polymers 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
- 229910052845 zircon Inorganic materials 0.000 description 1
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical compound [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/403—Cells and electrode assemblies
- G01N27/406—Cells and probes with solid electrolytes
- G01N27/407—Cells and probes with solid electrolytes for investigating or analysing gases
- G01N27/4075—Composition or fabrication of the electrodes and coatings thereon, e.g. catalysts
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Molecular Biology (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Measuring Oxygen Concentration In Cells (AREA)
Description
【発明の詳細な説明】
本発明は酸素イオン透過性固体電解質を用いた
酸素濃度センサ素子の電極及びその形成方法に関
するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode for an oxygen concentration sensor element using an oxygen ion permeable solid electrolyte and a method for forming the same.
内燃機関からの排ガス中の酸素濃度を検出する
ための酸素センサとしては例えば酸素イオン透過
性の固体電解質基板の両面に電極を形成し、両極
面間に電圧をかけると一方の極（陰極）から他方
の極（陽極）へ酸素イオンが透過する原理を利用
して酸素の流入量を制限し、これにより発生する
限界電流によつて排ガス中の酸素濃度を低い領域
から高い領域まで連続して正確に検出することが
できるいわゆる限界電流型酸素センサが開発され
使用されている。 As an oxygen sensor for detecting the oxygen concentration in exhaust gas from an internal combustion engine, for example, electrodes are formed on both sides of a solid electrolyte substrate that is permeable to oxygen ions, and when a voltage is applied between the two electrodes, one electrode (cathode) Utilizing the principle that oxygen ions permeate to the other electrode (anode), the inflow of oxygen is restricted, and the limiting current generated thereby accurately measures the oxygen concentration in the exhaust gas continuously from low to high regions. A so-called limiting current type oxygen sensor has been developed and is in use.
しかしながら従来の限界電流型酸素センサは焼
結体と電極の接触が良好ではないため固体電解質
と電極の界面における電気抵抗が大きく、かつ、
電極の付着状況による固体間の初期特性のバラツ
キが多く、特性不良の素子が頻出する等の問題が
あつた。 However, in conventional limiting current type oxygen sensors, the contact between the sintered body and the electrodes is not good, so the electrical resistance at the interface between the solid electrolyte and the electrodes is large, and
There was a problem that there was a lot of variation in the initial characteristics between solids depending on the adhesion state of the electrodes, and elements with poor characteristics frequently appeared.
本発明の目的は従来の酸素センサ素子を改良し
て、固体電解質に接する電極下層に金属中最も電
導度の高いAgを混在させることにより、固体電
解質と電極の界面の電気抵抗の低下した酸素濃度
センサ用の電極およびその形成法を提供すること
にある。 The purpose of the present invention is to improve the conventional oxygen sensor element by mixing Ag, which has the highest conductivity among metals, in the lower electrode layer in contact with the solid electrolyte, thereby reducing the oxygen concentration and reducing the electrical resistance at the interface between the solid electrolyte and the electrode. An object of the present invention is to provide an electrode for a sensor and a method for forming the same.
すなわち本発明の酸素濃度センサ用電極は酸素
イオン透過性固体電解質からなる素子本体と該素
子本体に設ける電極との界面に電極を構成する金
属と銀との混合層を設けたことを特徴としてい
る。 That is, the electrode for an oxygen concentration sensor of the present invention is characterized in that a mixed layer of metal and silver constituting the electrode is provided at the interface between an element body made of an oxygen ion permeable solid electrolyte and an electrode provided on the element body. .
また本発明の電極形成方法は酸素イオン透過性
固体電解質からなる素子本体の両面にAgとPt、
Rh、Ir、Pd及びこれらの合金の少くとも一種を
同時にスパツタリング蒸着し、更にその上をPt、
Rh、Ir、Pd及びこれらの合金の少くとも一種で
被覆することを特徴としている。 In addition, the electrode forming method of the present invention includes Ag and Pt on both sides of the device body made of an oxygen ion permeable solid electrolyte.
Rh, Ir, Pd, and at least one of these alloys are simultaneously sputter-deposited, and then Pt,
It is characterized by being coated with at least one of Rh, Ir, Pd, and alloys thereof.
次に本発明の電極およびその形成方法につき図
面に従つて説明する。 Next, an electrode of the present invention and a method for forming the same will be explained with reference to the drawings.
第１図は本発明の電極を用いた酸素センサ素子
Ｓの縦断面図で第２図は該電極の一部Ａの拡大断
面図である。素子本体１はZrO2、HfO2、ThO2、
Bi2O3等の酸化物にCaO、MgO、Y2O3、Yb2O3
等を安定剤として固溶させた緻密な焼結体を円板
状に成形した酸素イオン透過性の固体電解質であ
る。 FIG. 1 is a longitudinal sectional view of an oxygen sensor element S using the electrode of the present invention, and FIG. 2 is an enlarged sectional view of a part A of the electrode. The element body 1 is made of ZrO 2 , HfO 2 , ThO 2 ,
CaO, MgO, Y 2 O 3 , Yb 2 O 3 in oxides such as Bi 2 O 3
This is an oxygen ion-permeable solid electrolyte made by molding a dense sintered body into a disk shape in which a stabilizer is dissolved.
２ａは素子本体１の上に形成された電極下層で
銀（Ag）と電極用金属との混合層である。電極
用金属としては耐熱性耐酸化性および良好な導電
性を有する金属たとえば白金（Pt）、ロジウム
（Rh）、イリジウム（Ir）、パラジウム（Pd）等を
単独又は混合したものが使用される。したがつて
本発明の電極を形成するには素子本体１の表面に
AgとPt、Rh、Ir、Pd及びこれらの合金の少くと
も一種を同時にスパツタリングして厚さ0.1ない
し2μの薄膜を形成せしめる。Agの使用量は他の
電極金属に対し５ないし40モル％程度である。本
発明の電極２，３における電極下層２ａ，３ａは
Agが独立の粒子として混在する（図中黒点で示
す）、やゝ粗い層であつて酸素の透過に支障なか
らしめている。電極用金属を二種以上使用すると
きは、別個にスパツタリングしてもよいし、合金
としてスパツタリングしてもよい。 2a is an electrode lower layer formed on the element body 1, and is a mixed layer of silver (Ag) and an electrode metal. As the electrode metal, metals having heat resistance, oxidation resistance, and good conductivity, such as platinum (Pt), rhodium (Rh), iridium (Ir), palladium (Pd), etc. are used alone or in combination. Therefore, in order to form the electrode of the present invention, on the surface of the element body 1,
Ag and at least one of Pt, Rh, Ir, Pd, and their alloys are simultaneously sputtered to form a thin film with a thickness of 0.1 to 2 μm. The amount of Ag used is about 5 to 40 mol% relative to other electrode metals. The electrode lower layers 2a and 3a in the electrodes 2 and 3 of the present invention are
This is because it is a rather rough layer in which Ag is mixed as independent particles (indicated by black dots in the figure) and does not interfere with oxygen permeation. When using two or more types of electrode metals, they may be sputtered separately or as an alloy.
このようにして電極下層２ａ，３ａを形成せし
めた後、上記の電極用金属及び合金の少くとも一
種を電極下層２ａ，３ａの上にスパツタリング、
メツキ、蒸着または金属ペーストの焼付等の何れ
かの方法により厚さ0.5〜3μの電極上層２ｂ，３
ｂを形成せしめる。上層２ｂ，３ｂは下層２ａ，
３ａより緻密な層であつて耐熱性の低いAgを保
護している。 After forming the electrode lower layers 2a, 3a in this way, at least one of the above electrode metals and alloys is sputtered onto the electrode lower layers 2a, 3a.
Electrode upper layers 2b, 3 with a thickness of 0.5 to 3 μm are formed by plating, vapor deposition, baking of metal paste, etc.
Form b. The upper layers 2b and 3b are the lower layer 2a,
This layer is denser than 3a and protects Ag, which has lower heat resistance.
このように本発明の方法により形成された陰極
２、陽極３は更に多孔質４，５により被覆され
る。多孔質４，５は珪酸質、シヤモツト、アルミ
ナ質、クロミア質、ホルステライト質、スピネル
質、ジルコン質、ジルコニア質等の耐熱性無機物
質からなつている。陰極２に設けられる多孔質層
４は酸素の拡散律速を行なうものであり、陽極３
の多孔質層５より厚くしてある。ガスの透過率は
多孔質層４内の細孔の径と層の厚みに依存する。
一方、多孔質層５は陽極３を保護するためのもの
であり、陰極における程、厚くする必要はない。
これら多孔質層４，５の厚みが過大であると使用
中に剥離またはひゞ割れが生じやすく、また反対
に層、特に多孔質層４の厚みが不足するとガスの
拡散律速が不十分となりセンサの出力は直接に陰
極２、陽極３の酸素送出能力に依存することにな
る。また細孔の直径が過小であると、使用中に被
測定ガスに混在するゴミ等によつて目詰りを起こ
し、耐久性が低下する。 The cathode 2 and anode 3 thus formed by the method of the present invention are further covered with porous materials 4 and 5. The porous materials 4 and 5 are made of heat-resistant inorganic materials such as silicic acid, syamoto, alumina, chromia, forsterite, spinel, zircon, and zirconia. The porous layer 4 provided on the cathode 2 controls the diffusion rate of oxygen, and the porous layer 4 provided on the cathode 2 controls the diffusion rate of oxygen.
The porous layer 5 is made thicker than the porous layer 5 of FIG. The gas permeability depends on the diameter of the pores in the porous layer 4 and the thickness of the layer.
On the other hand, the porous layer 5 is for protecting the anode 3 and does not need to be as thick as the cathode.
If the thickness of these porous layers 4 and 5 is too large, peeling or cracking will easily occur during use.On the other hand, if the thickness of the layers, especially the porous layer 4, is insufficient, gas diffusion rate will be insufficient and the sensor will fail. The output directly depends on the oxygen delivery capabilities of the cathode 2 and anode 3. Furthermore, if the diameter of the pores is too small, the pores may become clogged with dust mixed in the gas to be measured during use, resulting in decreased durability.
上記酸素センサ素子Ｓの陰極２、陽極３にはそ
れぞれリード線６，６の一端が接続され、リード
線６，６の他端には直列的に電源７、電流計８が
接続されている。９はリード線６，６に並列的に
接続されている電圧計で陰極２、陽極３の間を流
れる限界電流を電流計８で測定し、印加電圧を電
圧計９で測定する。 One ends of lead wires 6, 6 are connected to the cathode 2, anode 3 of the oxygen sensor element S, respectively, and a power source 7 and an ammeter 8 are connected in series to the other ends of the lead wires 6, 6. A voltmeter 9 is connected in parallel to the lead wires 6, 6, and the limiting current flowing between the cathode 2 and the anode 3 is measured by the ammeter 8, and the applied voltage is measured by the voltmeter 9.
次に実施例によりさらに本発明を説明する。
7.5モルのY2O3で安定化したZrO2粉末により金型
を用いて直径6.0mm、厚さ0.3mmの円板を加圧成型
する。得られた成型体を空気中1680℃×１時間焼
成し焼結体として素子本体１を得る。この素子本
体１の表面に残存するフラツクスを10％弗化水素
溶液を用いて除去した後、表面の外周近傍および
側周面をフオトレジストでマスキングした。次に
マスキングされてない素子表面に10-12ないし
10-13mmHgの真空中でAgとPtとを同時にスパツ
タリング蒸着し、厚さ0.3μ、直径５mmの電極下層
２ａ，３ａを形成した。さらにこの上にPtのみ
のスパツタリングにより厚さ1μの電極上層２ｂ，
３ｂを形成させた。 Next, the present invention will be further explained by examples.
ZrO 2 powder stabilized with 7.5 mol of Y 2 O 3 is pressure-molded into a disk with a diameter of 6.0 mm and a thickness of 0.3 mm using a mold. The obtained molded body is fired in air at 1680° C. for 1 hour to obtain the element body 1 as a sintered body. After removing the flux remaining on the surface of the element body 1 using a 10% hydrogen fluoride solution, the vicinity of the outer periphery and side surfaces of the surface were masked with photoresist. Next, apply 10 -12 to the unmasked element surface.
Ag and Pt were simultaneously deposited by sputtering in a vacuum of 10 -13 mmHg to form electrode lower layers 2a and 3a having a thickness of 0.3 μm and a diameter of 5 mm. Furthermore, on top of this, an electrode upper layer 2b with a thickness of 1 μm is formed by sputtering only Pt.
3b was formed.
このようにして得た陰極２、陽極３に直接0.3
mmの白金線を圧着してリード線６，６とし更にそ
れぞれの層の表面にMgO、Al2O3のスピネル（平
均粒径40μ）を溶射して厚さ600μの陰極２側の多
孔質層４および厚さ300μの陽極３側の多孔質層
５を形成した。 0.3 directly to the cathode 2 and anode 3 obtained in this way.
mm platinum wires are crimped to form the lead wires 6, 6. Furthermore, MgO and Al 2 O 3 spinel (average particle size 40μ) is sprayed on the surface of each layer to form a porous layer on the cathode 2 side with a thickness of 600μ. 4 and a porous layer 5 on the anode 3 side having a thickness of 300 μm were formed.
得られた酸素センサ素子Ｓは第３図に示すホル
ダー２４に収納される。図中、１１は略円筒状ア
ルミナ碍管で、その内部には長手軸方向に貫通す
る中空部１１ａ，１１ａが設けられている。この
中空部１１ａ，１１ｂに装入されたリード線１
２，１２の先端を前記酸素センサ素子Ｓのリード
線６，６に接続することにより素子Ｓをアルミナ
碍管１１の先端に取りつける（図中、１３，１３
は接合部を示す）。前記アルミナ碍管１１の先端
に取付けられた素子Ｓの外周には発熱体１０がコ
イル状に巻かれてあり、更にその外周は通気孔１
４，１４を設けた保護カバー１５で保護されてい
る。発熱体１０はアルミナ碍管１１に設けられた
中空部１１ａ，１１ａとは別の図示しない中空部
に装入されたリード線と結ばれている。図中、１
６はホルダーを排気管に取りつけるためのフラン
ジ、１７はネジ孔、１８は素子Ｓ取付用のアルミ
ナ碍管１１とは別体にて該アルミナ碍管１１の上
部に設けられたアルミナ碍管、２０はリード線１
２，１２を介して素子Ｓの出力を外部へ取出すた
めの導線である。 The obtained oxygen sensor element S is housed in a holder 24 shown in FIG. In the figure, reference numeral 11 denotes a substantially cylindrical alumina insulator tube, and hollow portions 11a, 11a penetrating in the longitudinal direction are provided inside the tube. The lead wire 1 inserted into the hollow parts 11a and 11b
The element S is attached to the tip of the alumina insulator tube 11 by connecting the tips of 2 and 12 to the lead wires 6 and 6 of the oxygen sensor element S (see 13 and 13 in the figure).
indicates a joint). A heating element 10 is wound in a coil around the outer periphery of the element S attached to the tip of the alumina insulator tube 11, and the outer periphery is further provided with a ventilation hole 1.
It is protected by a protective cover 15 provided with numbers 4 and 14. The heating element 10 is connected to a lead wire inserted into a hollow part (not shown) provided in the alumina insulator tube 11, which is different from the hollow parts 11a, 11a. In the figure, 1
6 is a flange for attaching the holder to the exhaust pipe, 17 is a screw hole, 18 is an alumina insulator tube provided above the alumina insulator tube 11 separately from the alumina insulator tube 11 for attaching the element S, and 20 is a lead wire. 1
This is a conductive wire for taking out the output of the element S to the outside via 2 and 12.
上記構成の酸素センサを用いて内燃機関の排ガ
ス中の酸素濃度を検出するには素子Ｓが排ガスに
曝されるようにしてホルダー２４を排気管側壁に
固定する。このとき発熱体１０に電圧を加え素子
Ｓを所定の温度に加熱しておく。 To detect the oxygen concentration in the exhaust gas of an internal combustion engine using the oxygen sensor configured as described above, the holder 24 is fixed to the side wall of the exhaust pipe so that the element S is exposed to the exhaust gas. At this time, a voltage is applied to the heating element 10 to heat the element S to a predetermined temperature.
また比較例として実施例における電極下層の形
成を省略し、Ptのみを厚さ1μにスパツタリング
蒸着させ、その他の部分は実施例と全く同様の酸
素センサ素子S′を調製してその特性を比較した。 In addition, as a comparative example, an oxygen sensor element S' was prepared in which the formation of the electrode lower layer in the example was omitted, only Pt was sputter-deposited to a thickness of 1 μm, and the other parts were exactly the same as in the example, and the characteristics were compared. .
試験例
上記実施例の酸素センサ素子Ｓと比較例の酸素
センサ素子S′との性能を比較した。発熱体１０に
より素子ＳおよびS′を700℃になるように加熱し、
N2−O2系でのＶ／Ｉ特性測定したものが第４図
でイは実施例の素子Ｓによるもの、ロは比較例の
素子S′によるものである。素子Ｓでは抵抗S′より
小さいため、Ｖ／Ｉの立上り特性が急になつてい
る。これらのグラフを1V印加時の酸素濃度に出
力電流のグラフにおきかえたものが第５図で、
イ，ロはそれぞれ、第４図のイ，ロに対応する。
この図から明らかなように本発明の酸素センサ素
子イは、比較例の酸素センサ素子S′ロよりも高酸
素濃度領域まで直線性があり、８ないし10％の間
で出力電流に明らかな差が出ているが、比較例の
酸素センサ素子S′ロでは出力電流の差が小さく濃
度の分析精度の劣ることが示されている。Test Example The performance of the oxygen sensor element S of the above example and the oxygen sensor element S' of the comparative example was compared. The elements S and S' are heated to 700°C by the heating element 10,
The V/I characteristics measured in the N 2 -O 2 system are shown in FIG. 4, where A is for the element S of the example, and B is for the element S' of the comparative example. In the element S, since the resistance is smaller than the resistance S', the rise characteristic of V/I is steep. Figure 5 replaces these graphs with a graph of output current and oxygen concentration when 1V is applied.
A and B correspond to A and B in FIG. 4, respectively.
As is clear from this figure, the oxygen sensor element A of the present invention has more linearity than the comparative example oxygen sensor element S'B up to the high oxygen concentration region, and there is a clear difference in output current between 8 and 10%. However, in the comparative example oxygen sensor element S′, the difference in output current is small, indicating that the accuracy of concentration analysis is poor.
以上の如く、本発明の電極はその下層に銀とそ
の他の電極用金属の混合層が形成されていること
により、固体電解質との間の電気抵抗を少なくし
その上の電極上層により耐熱性をもたせることが
でき再現性の高いものとなる。また本発明の電極
の形成方法は固体電解質の表面を電極用金属で被
覆するに先立つてスパツタリング法により銀粒子
の介在する粗い電極下層が形成され酸素の透過に
支障のない電極を得ることができる。 As described above, since the electrode of the present invention has a mixed layer of silver and other electrode metals formed in the lower layer, the electrical resistance between it and the solid electrolyte can be reduced, and the upper electrode layer above it can improve heat resistance. It can be made to last and has high reproducibility. Furthermore, in the electrode forming method of the present invention, a rough electrode lower layer with silver particles interposed therein is formed by a sputtering method prior to coating the surface of the solid electrolyte with an electrode metal, thereby making it possible to obtain an electrode that does not impede oxygen permeation. .
第１図は本発明の電極を含む酸素濃度センサ素
子の断面図、第２図は本発明の電極の部分拡大断
面図、第３図は酸素濃度センサ素子をホルダー機
構に組込んだ側断面図、第４図は本発明の実施例
と比較例によるＶ／Ｉ特性図、第５図は本発明の
実施例と比較例における酸素濃度と出力電流の関
係を示すグラフを表わす。
図中、１……素子本体、２……陰極、２ａ……
陰極下層、２ｂ……陰極上層、３……陽極、３ａ
……陽極下層、３ｂ……陽極上層、４，５……多
孔質層、６……リード線、７……電源、８……電
流計、９……電圧計、１０……発熱体、１１……
アルミナ碍管、１１ａ……中空部、１２……リー
ド線、１３……接合部、１４……通気孔、１５…
…保護カバン、１６……フランジ、１７……ネジ
孔、１８……アルミナ碍管、１９……リヤカバ
ン、２０……リード線、２１……接続金具、２２
……リード線支持具、２３……ラバチユーブ、２
４……ホルダー、Ｓ……酸素センサ素子。
Fig. 1 is a sectional view of an oxygen concentration sensor element including an electrode of the present invention, Fig. 2 is a partially enlarged sectional view of the electrode of the invention, and Fig. 3 is a side sectional view of the oxygen concentration sensor element incorporated into a holder mechanism. , FIG. 4 is a V/I characteristic diagram according to an example of the present invention and a comparative example, and FIG. 5 is a graph showing the relationship between oxygen concentration and output current in an example of the present invention and a comparative example. In the figure, 1...Element body, 2...Cathode, 2a...
Cathode lower layer, 2b... Cathode upper layer, 3... Anode, 3a
... Anode lower layer, 3b ... Anode upper layer, 4, 5 ... Porous layer, 6 ... Lead wire, 7 ... Power supply, 8 ... Ammeter, 9 ... Voltmeter, 10 ... Heating element, 11 ……
Alumina insulator tube, 11a...Hollow part, 12...Lead wire, 13...Joint part, 14...Vent hole, 15...
... Protective bag, 16 ... Flange, 17 ... Screw hole, 18 ... Alumina insulator tube, 19 ... Rear bag, 20 ... Lead wire, 21 ... Connection fitting, 22
... Lead wire support, 23 ... Lava tube, 2
4...Holder, S...Oxygen sensor element.
Claims (1)
体と該素子本体に設ける電極との界面に電極を構
成する金属と銀との混合層を設けたことを特徴と
する酸素濃度センサの電極。 ２ 酸素イオン透過性固体電解質からなる素子本
体の両面に、Agと、Pt、Rh、Ir、Pdおよびこれ
らの合金の少くとも一種とを、同時にスパツタリ
ング蒸着し、更にその上をPt、Rh、Ir、Pdおよ
びこれらの合金の少くとも一種で被覆することを
特徴とする酸素濃度センサ電極の形成方法。[Claims] 1. An oxygen concentration sensor characterized in that a mixed layer of metal and silver constituting the electrode is provided at the interface between an element body made of an oxygen ion permeable solid electrolyte and an electrode provided on the element body. electrode. 2 Ag and at least one of Pt, Rh, Ir, Pd, and an alloy thereof are simultaneously sputter-deposited on both sides of the device body made of an oxygen ion-permeable solid electrolyte, and then Pt, Rh, Ir is further deposited on top of the sputtering. A method for forming an oxygen concentration sensor electrode, the electrode being coated with at least one of Pd, Pd, and an alloy thereof.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57040523A JPS58156849A (en) | 1982-03-15 | 1982-03-15 | Electrode of oxygen concentration sensor and its formation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57040523A JPS58156849A (en) | 1982-03-15 | 1982-03-15 | Electrode of oxygen concentration sensor and its formation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58156849A JPS58156849A (en) | 1983-09-17 |
| JPH033180B2 true JPH033180B2 (en) | 1991-01-17 |
Family
ID=12582856
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57040523A Granted JPS58156849A (en) | 1982-03-15 | 1982-03-15 | Electrode of oxygen concentration sensor and its formation |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58156849A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6130760A (en) * | 1984-07-24 | 1986-02-13 | Toyota Central Res & Dev Lab Inc | Oxygen sensor and manufacture thereof |
| JPH02210254A (en) * | 1989-02-10 | 1990-08-21 | Riken Corp | Composite electrode and its production |
| JP7146619B2 (en) * | 2018-12-21 | 2022-10-04 | 株式会社Soken | ammonia sensor |
-
1982
- 1982-03-15 JP JP57040523A patent/JPS58156849A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58156849A (en) | 1983-09-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1195601B1 (en) | Oxygen sensor element and manufacturing method thereof | |
| US4207159A (en) | Apparatus for measurement of oxygen concentration | |
| JPH0215017B2 (en) | ||
| US4126532A (en) | Oxygen sensor | |
| JP5173042B2 (en) | Manufacturing method of gas sensor | |
| GB1588176A (en) | Solid electrolyte thin film oxygen sensor having thin film heater | |
| US4395319A (en) | Lean sensor | |
| JPS61108953A (en) | Electrical connecting terminal of sensor element using ceramics | |
| JPH06502015A (en) | Sensor element for limiting current sensor for detection of λ value of mixed gas | |
| US6344118B1 (en) | Structure of oxygen sensing element | |
| JPS6118854A (en) | Oxygen concentration detecting element | |
| JPH0430537Y2 (en) | ||
| JPH033904B2 (en) | ||
| JP6999455B2 (en) | Sensor element and gas sensor | |
| JPS6337893B2 (en) | ||
| JPH0122899B2 (en) | ||
| JPS6126022B2 (en) | ||
| JPH033180B2 (en) | ||
| JP3677920B2 (en) | Oxygen concentration detector | |
| JP4605783B2 (en) | Gas sensor and gas sensor manufacturing method | |
| JPH01232252A (en) | Oxygen sensor element | |
| JPS58100746A (en) | Detector of oxygen concentration | |
| JPH065220B2 (en) | Oxygen concentration detector | |
| JPS5819554A (en) | Oxygen concentration detector | |
| JPS6326767Y2 (en) |