Gas sensor, gas monitoring device and vehicle

Abstract

The invention relates to a gas sensor, a gas monitoring device and a vehicle. The gas sensor comprises a pump unit, a detection unit and a gas diffusion structure. The pump unit comprises a first electrolyte layer, a first electrode and a second electrode, the first electrode and the second electrode are located on the two sides of the first electrolyte layer in the first direction respectively, and the first direction is perpendicular to the surface of the first electrolyte layer. The detection unit comprises a diffusion barrier structure and a detection cavity which are connected with each other, and the second electrode is connected with the detection cavity. At least part of the gas diffusion structure penetrates through the first electrolyte layer in the first direction and is connected with the diffusion barrier structure, and the gas diffusion structure comprises a porous material, so that the blocking risk of the diffusion barrier structure can be reduced.

Description

Technical Field

[0001] This application relates to the field of electronic technology, and more particularly to a gas sensor, a gas monitoring device, and a vehicle. Background Technology

[0002] An oxygen sensor uses a ceramic sensing element to measure the oxygen concentration in a car's exhaust pipe and converts the oxygen concentration signal into an electrical signal, which is then fed back to the engine control unit (ECU) to monitor and control the air-fuel ratio. This ensures complete fuel combustion and reduces emissions of toxic and harmful substances. The ECU then controls the fuel injection and air intake accordingly, ensuring the engine operates at the optimal air-fuel ratio, thus creating ideal conditions for the exhaust gas treatment by the three-way catalytic converter. If the fuel is too rich, the fuel quantity is reduced and the air intake is increased; if the fuel is too lean, the fuel quantity is increased and the air intake is reduced.

[0003] A diffusion barrier is a porous structure. Automobile exhaust contains unburned gasoline and other pollutants and particulate matter. When automobile exhaust directly passes through the diffusion barrier into the detection cavity, some unburned gasoline, particulate matter and other pollutants are adsorbed by the porous structure of the diffusion barrier, which in turn blocks the interconnecting pores inside the diffusion barrier and affects the entry of exhaust gas. Summary of the Invention

[0004] This application provides a gas sensor, a gas monitoring device, and a vehicle, designed to reduce the risk of blockage in gas barrier structures.

[0005] To achieve the above objectives, according to a first aspect of this application, a gas sensor is provided, comprising:

[0006] The pump unit includes a first electrolyte layer, a first electrode, and a second electrode. The first electrode and the second electrode are respectively located on both sides of the first electrolyte layer along a first direction, and the first direction is perpendicular to the surface of the first electrolyte layer.

[0007] The detection unit includes an interconnected diffusion barrier structure and a detection cavity, and the second electrode is connected to the detection cavity;

[0008] A gas diffusion structure, at least a portion of which penetrates the first electrolyte layer along the first direction and is connected to the diffusion barrier structure, wherein the gas diffusion structure comprises a porous material.

[0009] In some embodiments, both the gas diffusion structure and the diffusion barrier structure are porous materials, the porosity of the gas diffusion structure is greater than that of the diffusion barrier structure, and / or the pore size of the gas diffusion structure is greater than that of the diffusion barrier structure.

[0010] In some embodiments, the porosity of the gas diffusion structure is 45% to 70%, and the porosity of the diffusion barrier structure is 20% to 40%.

[0011] In some embodiments, the pore size of the gas diffusion structure is 5 micrometers to 10 micrometers, and the pore size of the diffusion barrier structure is 0.1 micrometers to 2 micrometers.

[0012] In some embodiments, the porous material comprises porous zirconium oxide and / or porous alumina.

[0013] In some embodiments, the gas diffusion structure further includes a noble metal, wherein the mass fraction of the noble metal in the gas diffusion structure is 0.1% to 0.5%.

[0014] In some embodiments, the detection unit further includes a second electrolyte layer and a third electrolyte layer, wherein the second electrolyte layer is located between the first electrolyte layer and the third electrolyte layer;

[0015] The diffusion barrier structure and the detection cavity are disposed within the second electrolyte layer.

[0016] In some embodiments, the diffusion barrier structure penetrates the second electrolyte layer along the first direction and is located between the first electrolyte layer and the third electrolyte layer.

[0017] In some embodiments, the gas diffusion structure has a first end face and a second end face opposite to each other, the first end face being higher than the side of the first electrolyte layer away from the second electrolyte layer, or flush with the side of the first electrolyte layer away from the second electrolyte layer.

[0018] In some embodiments, the gas diffusion structure is located within the first electrolyte layer, and the second end face is connected to the diffusion barrier structure.

[0019] In some embodiments, the gas diffusion structure further extends into the diffusion barrier structure along the first direction, and the dimension of the gas diffusion structure along the first direction is greater than or equal to the sum of the dimensions of the first electrolyte layer and the second electrolyte layer along the first direction.

[0020] In some embodiments, the orthogonal projection of the gas diffusion structure onto the first electrolyte layer is within the range of the orthogonal projection of the diffusion barrier structure onto the first electrolyte layer.

[0021] In some embodiments, the central axis of the gas diffusion structure along the first direction coincides with the central axis of the diffusion barrier structure along the first direction.

[0022] In some embodiments, the orthographic projection of the detection cavity onto the first electrolyte layer coincides with the orthographic projection of the second electrode onto the first electrolyte layer.

[0023] In some embodiments, both the detection cavity and the second electrode are arranged around the diffusion barrier structure.

[0024] In some embodiments, the detection unit further includes a fourth electrolyte layer and a third electrode, wherein the fourth electrolyte layer and the third electrode are both located on the side of the third electrolyte layer away from the second electrolyte layer;

[0025] The fourth electrolyte layer is provided with a standard gas channel, and the standard gas channel is connected to the third electrode.

[0026] In some embodiments, the detection unit further includes a fourth electrode located on the side of the third electrolyte layer closer to the second electrolyte layer;

[0027] The orthographic projection of the fourth electrode onto the first electrolyte layer coincides with the orthographic projection of the detection cavity onto the first electrolyte layer.

[0028] In some embodiments, the detection cavity and the second electrode are both connected to one side of the diffusion barrier structure and are both arranged along a second direction, which is parallel to the surface of the first electrolyte layer and perpendicular to the first direction.

[0029] In some embodiments, the detection unit further includes a third electrode, which is located on the side of the first electrolyte layer away from the first electrode and is spaced apart from the second electrode;

[0030] The second electrolyte layer is also provided with a standard gas channel, which is connected to the third electrode and is spaced apart from the detection chamber.

[0031] In some embodiments, the detection unit further includes a fourth electrode located on the side of the third electrolyte layer closer to the second electrolyte layer;

[0032] The fourth electrode includes a first electrode portion, a second electrode portion, and a third electrode portion connected sequentially in a third direction. The orthographic projection of the first electrode portion onto the first electrolyte layer coincides with the detection cavity. The second electrode portion is located between a portion of the second electrolyte layer and the third electrolyte layer. The third electrode portion has a portion of the second electrolyte layer between it and the standard gas channel.

[0033] In some embodiments, a heating unit is further included on the side of the detection unit away from the pump unit, the heating unit including a heating electrode, an insulating layer surrounding the heating electrode, and a fifth electrolyte layer surrounding the insulating layer.

[0034] In some embodiments, the system further includes a heating unit located on the side of the detection unit away from the pump unit. The heating unit includes a heating electrode, a first insulating layer and a second insulating layer located on opposite sides of the heating electrode, a first sub-electrolyte layer located on the side of the first insulating layer away from the heating electrode, and a second sub-electrolyte layer located on the side of the second insulating layer away from the heating electrode. The heating unit also includes:

[0035] A first heterogeneous bonding layer is located between the first insulating layer and the first sub-electrolyte layer, and the first heterogeneous bonding layer includes a first bonding portion and a second bonding portion connected in the same layer. The first bonding portion is made of the same material as the first insulating layer, and the second bonding portion is made of the same material as the first sub-electrolyte layer.

[0036] In some embodiments, at least a portion of the first joint is disposed around at least a portion of the second joint, and / or at least a portion of the second joint is disposed around at least a portion of the first joint.

[0037] In some embodiments, the first joint includes a first connecting portion and at least two first intersecting portions, the first connecting portion connecting the at least two first intersecting portions; the second joint includes a second connecting portion and at least two second intersecting portions, the second intersecting portions connecting the at least two second intersecting portions.

[0038] Two adjacent first intersections and two adjacent first connecting parts are arranged around one second intersection, and two adjacent second intersections and two adjacent second connecting parts are arranged around one first intersection.

[0039] In some embodiments, the first intersection has a first end and a second end, the first end being connected to the first connecting portion and the second end being connected to the second connecting portion;

[0040] The second intersection has a third end and a fourth end, the third end being connected to the second connecting part, and the fourth end being connected to the first connecting part.

[0041] In some embodiments, the first sub-electrolyte layer extends along a first direction, the first connecting portion and the second connecting portion are disposed opposite each other in a second direction and both extend along the first direction, and the first direction intersects the second direction;

[0042] The first intersection and the second intersection are alternately arranged along the first direction and both extend along the second direction.

[0043] In some embodiments, the first sub-electrolyte layer extends along a first direction, the first connecting portion and the second connecting portion are disposed opposite to each other in the first direction and both extend along a second direction, and the first direction intersects the second direction;

[0044] The first intersection and the second intersection are alternately arranged along the second direction and both extend along the first direction.

[0045] In some embodiments, the first joint portion includes a plurality of first sub-joint portions, and the second joint portion includes a plurality of second sub-joint portions, with the plurality of first sub-joint portions and the plurality of second sub-joint portions alternately arranged around each other.

[0046] In some embodiments, the top view of the second sub-junction and / or the first sub-junction along a third direction is a U-shape, where the third direction is the stacking direction of the first sub-electrolyte layer and the first insulating layer.

[0047] In some embodiments, it also includes:

[0048] The first reinforcing layer is located between the first heterogeneous bonding layer and the first sub-electrolyte layer, and the first reinforcing layer and the first sub-electrolyte layer are made of the same material.

[0049] In some embodiments, the thickness of the first reinforcing layer along a third direction is less than the thickness of the first sub-electrolyte layer in that third direction, where the third direction is the stacking direction of the first sub-electrolyte layer and the first insulating layer.

[0050] In some embodiments, the thickness of the first reinforcing layer in the third direction is 10 micrometers to 50 micrometers.

[0051] In some embodiments, the thickness of the first heterogeneous bonding layer along a third direction is less than the thickness of the first sub-electrolyte layer in that third direction, where the third direction is the stacking direction of the first sub-electrolyte layer and the first insulating layer.

[0052] In some embodiments, the thickness of the first heterogeneous bonding layer in the third direction is 10 micrometers to 50 micrometers.

[0053] In some embodiments, the thickness of the first sub-electrolyte layer in the third direction is 150 micrometers to 300 micrometers.

[0054] In some embodiments, the material of the first sub-electrolyte layer includes zirconium oxide and additives, the additives including yttrium oxide, cerium oxide, or calcium oxide.

[0055] In some embodiments, the content of the additive in the first sub-electrolyte layer is 5 mol% to 10 mol%.

[0056] In some embodiments, the top view area of ​​the first bonding portion along a third direction is 20% to 80% of the top view area of ​​the first heterogeneous bonding layer in that third direction, where the third direction is the stacking direction of the first sub-electrolyte layer and the first insulating layer.

[0057] In some embodiments, a second heterogeneous bonding layer is further included, which is located between the second insulating layer and the second sub-electrolyte layer. The second heterogeneous bonding layer includes a third bonding portion and a fourth bonding portion connected in the same layer. The third bonding portion is made of the same material as the second insulating layer, and the fourth bonding portion is made of the same material as the second sub-electrolyte layer.

[0058] In some embodiments, the heating unit further includes:

[0059] The second reinforcing layer is located between the second heterogeneous bonding layer and the second sub-electrolyte layer, and the second reinforcing layer and the second sub-electrolyte layer are made of the same material.

[0060] In some embodiments, a heating unit is further included on the side of the detection unit away from the pump unit. The heating unit includes a heating electrode extending along a first direction and includes a heating portion, a buffer portion, and a lead portion arranged along the first direction. The buffer portion is located between the heating portion and the lead portion, and the total resistance of the buffer portion is less than the total resistance of the heating portion and greater than the total resistance of the lead portion.

[0061] In some embodiments, the total resistance of the heating portion is 55% to 65% of the total resistance of the heating electrode, the total resistance of the buffer portion is 15% to 30% of the total resistance of the heating electrode, and the total resistance of the lead portion is 15% to 30% of the total resistance of the heating electrode.

[0062] In some embodiments, the temperature of the heating part is 400°C to 800°C, the temperature of the buffer part is 200°C to 800°C, and the temperature of the lead part is less than 200°C.

[0063] In some embodiments, the lead portion includes a first sub-lead portion and a second sub-lead portion disposed opposite to each other in a second direction, the second direction being perpendicular to the first direction;

[0064] The buffer section includes a first sub-buffer section connected to the first sub-lead section and a second sub-buffer section connected to the second sub-lead section;

[0065] The heating section includes a first end connected to the first sub-buffer section and a second end connected to the second sub-buffer section;

[0066] The size of the first sub-buffer portion gradually increases from the first end to the first sub-lead portion along the second direction, and the size of the second sub-buffer portion gradually increases from the second end to the second sub-lead portion along the second direction.

[0067] In some embodiments, the minimum dimension of the first sub-buffer portion along the second direction is greater than or equal to the dimension of the first end along the second direction;

[0068] The maximum dimension of the first sub-buffer portion along the second direction is less than or equal to the dimension of the first sub-lead portion along the second direction.

[0069] In some embodiments, the heating electrode further includes a transition portion, the transition portion including a first sub-transition portion connected between the first sub-buffer portion and the first sub-lead portion, and a second sub-transition portion connected between the second sub-buffer portion and the second sub-lead portion;

[0070] The size of the first sub-transition portion gradually increases along the second direction from the first sub-buffer portion to the first sub-lead portion, and the size of the second sub-transition portion gradually increases along the second direction from the second sub-buffer portion to the second sub-lead portion.

[0071] In some embodiments, the dimension of the lead portion along the first direction is greater than the dimension of the heating portion along the first direction, and the dimension of the lead portion along the first direction is greater than the dimension of the buffer portion along the first direction.

[0072] In some embodiments, the resistivity of the buffer portion is greater than the resistivity of the lead portion.

[0073] In some embodiments, the heating part further includes a plurality of sub-heating parts disposed along the first direction, and the plurality of sub-heating parts are connected in series.

[0074] The dimension of the heating part along the first direction is greater than or equal to the dimension of the buffer part along the first direction.

[0075] In some embodiments, the resistivity of the buffer portion is less than or equal to the resistivity of the heating portion.

[0076] In some embodiments, the resistivity of the heating part is 35 μΩ·cm to 50 μΩ·cm, and the resistivity of the buffer part is 10 μΩ·cm to 25 μΩ·cm.

[0077] In some embodiments, the dimension of the buffer portion along the first direction is 50% to 100% of the dimension of the heating portion along the first direction.

[0078] In some embodiments, the heating electrode has a symmetry axis extending along the first direction, and the first sub-buffer portion and the second sub-buffer portion are symmetrical about the symmetry axis;

[0079] The first sub-buffer portion has a first outer side surface away from the second sub-buffer portion, and the heating portion has a second outer side surface connected to the first outer side surface, and the first outer side surface and the second outer side surface extend in the first direction, or the first outer side surface is located on the side of the second outer side surface closer to the second sub-buffer portion.

[0080] In some embodiments, the first sub-buffer portion has an inner side surface near the second sub-buffer portion, the inner side surface being a flat surface or a stepped surface.

[0081] According to a second aspect of this application, a gas monitoring device is provided, including the gas sensor in any of the above embodiments.

[0082] According to a third aspect of this application, a vehicle is provided that includes the aforementioned gas monitoring device.

[0083] This application provides a gas sensor, a gas monitoring device, and a vehicle. The gas sensor includes a pump unit, a detection unit, and a gas diffusion structure. The pump unit includes a first electrolyte layer, a first electrode, and a second electrode, respectively located on opposite sides of the first electrolyte layer along a first direction perpendicular to the surface of the first electrolyte layer. The detection unit includes an interconnected diffusion barrier structure and a detection chamber, with the second electrode connected to the detection chamber. At least a portion of the gas diffusion structure penetrates the first electrolyte layer along the first direction and is connected to the diffusion barrier structure, and the gas diffusion structure comprises a porous material. Therefore, external exhaust gas can enter the detection chamber through the gas diffusion structure via the diffusion barrier structure. The porous material can adsorb pollutants and impurity particles in the exhaust gas, thereby reducing the entry of pollutants and impurity particles into the diffusion barrier structure and thus reducing the risk of blockage of the diffusion barrier structure. Attached Figure Description

[0084] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0085] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0086] Figure 1 This is a three-dimensional structural diagram of a gas sensor provided in some embodiments of this application;

[0087] Figure 2 This is provided by some embodiments of this application. Figure 1 Cross-sectional view of the gas sensor along the YZ direction;

[0088] Figure 3 This is provided by some embodiments of this application. Figure 2 A top view of the structure of the gas sensor;

[0089] Figure 4 This is provided by some embodiments of this application. Figure 1 Cross-sectional view of the gas sensor along the XZ direction;

[0090] Figure 5 This is provided by some embodiments of this application. Figure 4 Top view of the gas sensor along section A-A1;

[0091] Figure 6 This is a schematic flowchart of a method for preparing a gas sensor according to some embodiments of this application;

[0092] Figure 7 This is an exploded structural diagram of a heating unit provided in some embodiments of this application;

[0093] Figure 8 This is provided by some embodiments of this application. Figure 7 A schematic diagram of the structure of the first heterogeneous bonding layer at position A;

[0094] Figure 9 This is provided by some embodiments of this application. Figure 7 A cross-sectional view of the first insulating layer, the first heterogeneous bonding layer and the first reinforcing layer along the first direction and the third direction;

[0095] Figure 10 This is an exploded structural diagram of a heating unit provided in some embodiments of this application;

[0096] Figure 11 This is a schematic diagram of the connection structure of the first joint and the second joint provided in some embodiments of this application;

[0097] Figure 12 This is a top view schematic diagram of the heating electrode provided in some embodiments of this application;

[0098] Figure 13This is a top view schematic diagram of the heating electrode provided in some embodiments of this application;

[0099] Figure 14 This is a top view schematic diagram of the heating electrode provided in some embodiments of this application. Detailed Implementation

[0100] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0101] This paper uses Cartesian coordinates to represent directions, where "Z" represents the first direction, "X" represents the second direction, and "Y" represents the third direction. The first, second, and third directions intersect each other, that is, X, Y, and Z intersect each other, for example, they can be perpendicular to each other or form a certain angle.

[0102] Please see Figure 1 and Figure 2 , Figure 1 This is a three-dimensional structural diagram of a gas sensor provided in some embodiments of this application. Figure 2 This is provided by some embodiments of this application. Figure 1 A cross-sectional view of the gas sensor along the YZ direction.

[0103] The gas sensor 100 includes a pump unit 10, a detection unit 20, and a gas diffusion structure 30. The pump unit 10 includes a first electrolyte layer 11, a first electrode 12, and a second electrode 13. The first electrode 12 and the second electrode 13 are located on opposite sides of the first electrolyte layer 11 along a first direction Z, which is perpendicular to the surface of the first electrolyte layer 11. The detection unit 20 includes a diffusion barrier structure 23 and a detection chamber 24 connected to each other, and the second electrode 13 is connected to the detection chamber 24. At least a portion of the gas diffusion structure 30 penetrates the first electrolyte layer 11 along the first direction Z and is connected to the diffusion barrier structure 23. The gas diffusion structure 30 comprises a porous material. Therefore, external exhaust gas can enter the detection chamber 24 through the gas diffusion structure 30 and the diffusion barrier structure 23. The porous material can adsorb pollutants and impurity particles in the exhaust gas, thereby reducing the entry of pollutants and impurity particles into the diffusion barrier structure 23 and thus reducing the risk of blockage of the diffusion barrier structure 23.

[0104] In this process, after the external exhaust gas enters the detection chamber 24 through the gas diffusion structure 30 and the diffusion barrier structure 23, the second electrode 13 serves as the detection electrode to detect the oxygen content in the exhaust gas.

[0105] The detection unit 20 may further include a second electrolyte layer 21 and a third electrolyte layer 22, wherein the second electrolyte layer 21 is located between the first electrolyte layer 11 and the third electrolyte layer 22, and the diffusion barrier structure 23 and the detection cavity 24 are disposed within the second electrolyte layer 21.

[0106] like Figure 1 As shown, the gas sensor 100 as a whole can extend along a third direction Y. Specifically, the first electrolyte layer 11, the second electrolyte layer 21, and the third electrolyte layer 22 can all extend along a third direction Y.

[0107] The materials of the first electrolyte layer 11, the second electrolyte layer 21, and the third electrolyte layer 22 may all include zirconium oxide and additives, wherein the additives include yttrium oxide or scandium oxide.

[0108] In some embodiments, the additive content in the first electrolyte layer 11 is 3 mol% to 8 mol%, which provides good conductivity and moderate cost.

[0109] Both the first electrode 12 and the second electrode 13 can be platinum-containing ceramic electrodes, and the mass fraction of platinum in the ceramic electrodes is 40% to 70%.

[0110] like Figure 2 As shown, the gas sensor 100 may further include a heating unit 40 located on the side of the detection unit 20 away from the pump unit 10. The heating unit 40 includes a heating electrode 41, an insulating layer 42 surrounding the heating electrode 41, and a fifth electrolyte layer 43 surrounding the insulating layer 42. The material of the insulating layer 42 may include alumina or aluminum nitride, with a density greater than 99%.

[0111] The pump unit 10 may further include a protective layer 14, which is located on the surface of the first electrolyte layer 11 near the first electrode 12 and covers the first electrode 12. The top view of the first electrode 12 may be annular, and the top view of the protective layer 14 may also be annular. The protective layer 14 may be porous zirconium oxide or alumina, with a porosity of 15% to 45% and a pore size of 0.1 μm to 2 μm.

[0112] The exhaust gas from the vehicle passes through the gas diffusion structure 30 and the diffusion barrier structure 23 in sequence before entering the detection chamber 24. It is detected by the second electrode 13 and compared with a standard gas. If it does not meet the critical value requirement, the engine control element will apply a pumping current through the first electrode 12 and the second electrode 13. Since the first electrolyte layer 11 is an ion conductor, the first electrode 12, the first electrolyte layer 11 and the second electrode 13 form a current path, which can pump oxygen into or out of the detection chamber 24 so that the engine operates in the optimal air-fuel ratio state.

[0113] In some embodiments, both the gas diffusion structure 30 and the diffusion barrier structure 23 are porous materials. The porosity of the gas diffusion structure 30 is greater than that of the diffusion barrier structure 23, and / or the pore size of the gas diffusion structure 30 is greater than that of the diffusion barrier structure 23. Therefore, the gas diffusion structure 30 can adsorb some larger impurity particles and pollutants, and can allow the exhaust gas to pass smoothly to the diffusion barrier structure 23.

[0114] Specifically, the porosity of the gas diffusion structure 30 can be 45%–70%, and the porosity of the diffusion barrier structure 23 can be 20%–40%. The pore size of the gas diffusion structure 30 can be 5 micrometers–10 micrometers, and the pore size of the diffusion barrier structure 23 can be 0.1 micrometers–2 micrometers. Since the porosity of the gas diffusion structure 30 is less than or equal to 76% and the pore size is less than or equal to 10 micrometers, the gas diffusion structure 30 can trap or adsorb some impurity particles and pollutants, reducing the likelihood of these impurity particles entering the diffusion barrier structure and causing blockage. Since the porosity of the gas diffusion structure 30 is greater than or equal to 40% and the pore size is greater than or equal to 5 micrometers, this allows gas molecules in the exhaust gas to enter the diffusion barrier structure as much as possible. The porosity of the diffusion barrier structure 23 is 20%–40%, and the pore size is between 0.1 micrometers and 2 micrometers, allowing for further filtration of smaller impurity particles in the exhaust gas and allowing gas molecules to enter the detection chamber 24 for detection.

[0115] In some embodiments, the gas diffusion structure 30 includes porous zirconia and / or porous alumina, and the diffusion barrier structure 23 may also include porous zirconia and / or porous alumina.

[0116] For example, the gas diffusion structure 30 and the diffusion barrier structure 23 may be made of the same material.

[0117] In some embodiments, the gas diffusion structure 30 further includes a noble metal, wherein the mass fraction of the noble metal in the gas diffusion structure 30 is 0.1% to 0.5%. The noble metal can reduce the risk of electrode passivation in the detection chamber 24 caused by pollutants such as Pb, P, Si, and S in the exhaust gas, improve the control accuracy of the pump current and the detection accuracy, and extend the service life.

[0118] Specifically, the noble metal includes at least one of Pt, Pd, and Rh. In some embodiments, the diffusion barrier structure 23 penetrates the second electrolyte layer 21 along the first direction Z and is located between the first electrolyte layer 11 and the third electrolyte layer 22. Specifically, the dimension of the diffusion barrier structure 23 along the first direction Z is equal to the dimension of the second electrolyte layer 21 along the first direction Z. More specifically, the upper surface of the diffusion barrier structure 23 may be flush with the upper surface of the second electrolyte layer 21, and the lower surface of the diffusion barrier structure 23 may be flush with the lower surface of the second electrolyte layer 21.

[0119] In some embodiments, the gas diffusion structure 30 has a first end face 31 and a second end face 32 opposite to each other. The first end face 31 is flush with or higher than the side of the first electrolyte layer 11 away from the second electrolyte layer 21. This way, the upper surface of the gas diffusion structure 30 is free from depression defects, which is beneficial for the subsequent assembly of the gas sensor 100.

[0120] like Figure 2 As shown, the gas diffusion structure 30 is located within the first electrolyte layer 11, and the second end face 32 is connected to the diffusion barrier structure 23. Specifically, the dimension of the gas diffusion structure 30 along the first direction Z is equal to the dimension of the first electrolyte layer 11 along the first direction Z. Therefore, the second end face 32 of the gas diffusion structure 30 is flush with the other side (lower surface) of the second electrolyte layer 21, that is, the second end face 32 is connected to the upper surface of the diffusion barrier structure 23.

[0121] In some embodiments, the orthogonal projection of the gas diffusion structure 30 onto the first electrolyte layer 11 is within the range of the orthogonal projection of the diffusion barrier structure 23 onto the first electrolyte layer 11.

[0122] In some embodiments, the orthographic projection of the detection cavity 24 onto the first electrolyte layer 11 coincides with the orthographic projection of the second electrode 13 onto the first electrolyte layer 11, thereby maximizing the effective detection area of ​​the second electrode 13.

[0123] Please combine Figure 3 , Figure 3 This is provided by some embodiments of this application. Figure 2 The schematic diagram of the gas sensor from top view shows that the relative positions of the gas diffusion structure 30, the diffusion barrier structure 23, and the second electrode 13 have been omitted. Figure 2 The structure consists of the first electrolyte layer 11 and above.

[0124] Among them, the detection cavity 24 ( Figure 3 (Not shown) and the second electrode 13 are both connected to one side of the diffusion barrier structure 23 and are both arranged along the second direction X, which is parallel to the surface of the first electrolyte layer 11 and perpendicular to the first direction Z and the third direction Y.

[0125] like Figure 3 As shown, the gas diffusion structure 30 can be columnar, and the diffusion barrier structure 23 can be cuboid. The central axis of the gas diffusion structure 30 along the first direction Z coincides with the central axis of the diffusion barrier structure 23 along the first direction Z, which facilitates the diffusion of exhaust gas within the diffusion barrier structure 23. Specifically, the central axis of the gas diffusion structure 30 is an axis passing through the center of the cylinder along the first direction Z, and the central axis of the diffusion barrier structure 23 is an axis passing through the center of the cuboid along the first direction Z.

[0126] like Figure 2 and Figure 3 As shown, the detection unit 20 may further include a third electrode 25, which is located on the side of the first electrolyte layer 11 away from the first electrode 12 and is spaced apart from the second electrode 13. A standard gas channel 26 is also provided within the second electrolyte layer 21, which is connected to the third electrode 25 and spaced apart from the detection chamber 24. Therefore, the third electrode 25 is used to detect the oxygen content of the standard gas. A portion of the second electrolyte layer 21 is located between the third electrode 25 and the second electrode 13, and this portion of the second electrolyte layer 21 is also located between the standard gas channel 26 and the detection chamber 24. This embodiment utilizes the first electrolyte layer 11 and the second electrolyte layer 21 to form the standard gas channel 26 and the third electrode 25 for detecting the standard gas, which can save materials and costs, reduce the thickness of the gas sensor 100, and thus reduce the overall size.

[0127] In some embodiments, the detection unit 20 further includes a fourth electrode 27 located on the side of the third electrolyte layer 22 closest to the second electrolyte layer 21. In one embodiment, the fourth electrode 27 may be connected to the second electrode 13.

[0128] The fourth electrode 27 includes a first electrode portion 271, a second electrode portion 272, and a third electrode portion 273 connected sequentially in a third direction Y. The orthographic projection of the first electrode portion 271 onto the first electrolyte layer 11 coincides with the detection cavity 24. The second electrode portion 272 is located between the second electrolyte layer 21 and the third electrolyte layer 22. The third electrode portion 273 has a portion of the second electrolyte layer 21 between it and the standard gas channel 26. Therefore, the fourth electrode 27 can detect the oxygen content of the exhaust gas entering from the diffusion barrier structure 23 together with the second electrode 13, increasing the effective detection area of ​​the electrode. Furthermore, the fourth electrode 27, together with the second electrode 13, also serves as part of the pump unit 10.

[0129] like Figure 2 As shown, the second electrolyte layer 21 includes an L-shaped portion near the second electrode 13. The vertical portion of the L-shaped portion (the portion disposed along the first direction Z) isolates the second electrode 13 and the third electrode 25, and isolates the detection chamber 24 and the standard gas channel 26. The lateral portion of the L-shaped portion (the portion disposed along the third direction Y) is located between the standard gas channel 26 and the fourth electrode 27.

[0130] Please see Figure 4 and Figure 5 , Figure 4 This is provided by some embodiments of this application. Figure 1 A cross-sectional view of the gas sensor along the XZ direction. Figure 5 This is provided by some embodiments of this application. Figure 4 The top view of the gas sensor along section A-A1 mainly shows the relative positions of the gas diffusion structure 30A, the diffusion barrier structure 23A, and the fourth electrode 27A. For ease of understanding and brief explanation, the same structures as in the above embodiments continue to use the same reference numerals, and the same structures will not be described in detail. This embodiment only provides detailed descriptions of the different structures.

[0131] The gas sensor 200 in this embodiment is the same as described above. Figure 2 The main differences in the embodiments are in the second electrode 13A, the second electrolyte layer 21A in the detection unit 20A, the diffusion barrier structure 23A and the detection cavity 24A, the third electrode 25A, the standard gas channel 26A and the fourth electrode 27A, and the gas diffusion structure 30A. Among them, the gas diffusion structure 30A includes a first end face 31A and a second end face 32A.

[0132] In some embodiments, the gas diffusion structure 30A further extends along the first direction Z into the diffusion barrier structure 23A, and the dimension of the gas diffusion structure 30A along the first direction Z is greater than or equal to the sum of the dimensions of the first electrolyte layer 11 and the second electrolyte layer 21A along the first direction Z.

[0133] like Figure 4 As shown, the dimension of the gas diffusion structure 30A along the first direction Z is equal to the sum of the dimensions of the first electrolyte layer 11 and the second electrolyte layer 21A along the first direction Z. That is, the second end face 32A of the gas diffusion structure 30A is flush with the lower surface of the diffusion barrier structure 23A and is located on the surface of the third electrolyte layer 22.

[0134] like Figure 4 and Figure 5 As shown, the gas diffusion structure 30A is columnar, and the diffusion barrier structure 23A is arranged around the gas diffusion structure 30A. This can increase the contact area between the gas diffusion structure 30A and the diffusion barrier structure 23A, which is beneficial to gas transmission.

[0135] The detection cavity 24A and the second electrode 13A are both arranged around the diffusion barrier structure 23A, and the top view shape of the detection cavity 24A and the second electrode 13A are both annular. This can increase the contact area between the diffusion barrier structure 23A and the detection cavity 24A, which is beneficial to gas transmission.

[0136] In some embodiments, the detection unit 20 further includes a fourth electrolyte layer 28 and a third electrode 25A, both of which are located on the side of the third electrolyte layer 22 away from the second electrolyte layer 21A. A standard gas channel 26A is provided within the fourth electrolyte layer 28, and the standard gas channel 26A is connected to the third electrode 25A.

[0137] In some embodiments, the detection unit 20 may further include a fourth electrode 27A, which is located on the side of the third electrolyte layer 22 near the second electrolyte layer 21A. The orthographic projection of the fourth electrode 27A onto the first electrolyte layer 11 coincides with the orthographic projection of the detection cavity 24A onto the first electrolyte layer 11. The fourth electrode 27A can be used together with the second electrode 13A to detect the oxygen content in the exhaust gas, and the fourth electrode 27A can also be used together with the second electrode 13A as part of the pump unit 10, i.e., the fourth electrode 27A can be reused.

[0138] The gas sensor provided in this application includes a pump unit 10, a detection unit 20 / 20A, and a gas diffusion structure 30 / 30A. The pump unit 10 includes a first electrolyte layer 11, a first electrode 12, and a second electrode 13 / 13A. The first electrode 12 and the second electrode 13 / 13A are located on opposite sides of the first electrolyte layer 11 along a first direction Z, which is perpendicular to the surface of the first electrolyte layer 11. The detection unit 20 / 20A includes an interconnected diffusion barrier structure 23 / 23A and a detection cavity 24 / 24A, and the second electrode 13 / 13A is connected to the detection cavity 24 / 24A. At least a portion of the gas diffusion structure 30 / 30A penetrates the first electrolyte layer 11 along the first direction Z and is connected to the diffusion barrier structure 23 / 23A. The gas diffusion structure 30 / 30A comprises a porous material. Therefore, external exhaust gas can enter the detection chamber 24 / 24A through the gas diffusion structure 30 / 30A and the diffusion barrier structure 23 / 23A. The porous material can adsorb pollutants and impurity particles in the exhaust gas, thereby reducing the amount of pollutants and impurity particles entering the diffusion barrier structure 23 / 23A, and thus reducing the risk of blockage of the diffusion barrier structure 23 / 23A.

[0139] Please see Figure 6 , Figure 6 This is a schematic flowchart illustrating a method for fabricating a gas sensor according to some embodiments of this application. This method can be used to fabricate the gas sensor 200 described above, and therefore can be referred to... Figure 2 The fabrication method of the gas sensor 200 includes the following steps S1 to S4. The fabrication of the gas sensor 100 can be carried out with reference to steps S1 to S4, and adaptive modifications can be made to form the corresponding structure.

[0140] Step S1: Provide a first electrolyte layer 11, and form a first electrode 12 and a second electrode 13A on both sides of the first electrolyte layer 11 along the first direction Z, wherein the first direction Z is perpendicular to the surface of the first electrolyte layer 11.

[0141] In some embodiments, the first electrode 12 and the second electrode 13A can be formed by screen printing, and a protective layer 14 can be screen printed on the first electrode 12.

[0142] Step S2: Provide a third electrolyte layer 22, and form a second electrolyte layer 21A, a diffusion barrier structure 23A and a detection cavity 24A on one side of the third electrolyte layer 22, wherein the diffusion barrier structure 23A and the detection cavity 24A are disposed within the second electrolyte layer 21A.

[0143] In some embodiments, a diffusion barrier structure 23A and a fourth electrode 27A, as well as a cavity sacrificial layer, can be printed on one side of the third electrolyte layer 22 first, and then a second electrolyte layer 21A can be printed on, so that the diffusion barrier structure 23A, the fourth electrode 27A, and the cavity sacrificial layer are located within the second electrolyte layer 21A.

[0144] Step S3: Combine the first electrolyte layer 11 with the third electrolyte layer 22, so that the second electrode 13A is connected to the detection cavity 24A.

[0145] In some embodiments, prior to step S3, a third electrode 25A and a standard gas channel 26A may be printed on the other side of the third electrolyte layer 22, and then a fourth electrolyte layer 28 may be printed such that the third electrode 25A and the standard gas channel 26A are located within the fourth electrolyte layer 28. Afterward, the side of the first electrolyte layer 11 having the second electrode 13A is bonded to the side of the third electrolyte layer 22 having the fourth electrode 27A.

[0146] The fabrication method of the gas sensor 100 may further include: 1) providing a fifth electrolyte layer 43, and sequentially printing an insulating layer 42, a heating electrode 41, an insulating layer 42 and a fifth electrolyte layer 43 on the fifth electrolyte layer 43 to form a heating unit 40; 2) then combining one side of the third electrolyte layer 22 having a standard gas channel 26A with one side of the heating unit 40; 3) placing the above-formed stacked structure into a furnace for sintering at a temperature of 1350℃~1450℃ for 2h~3h, wherein the cavity sacrificial layer is burned off to form a detection cavity 24A.

[0147] Step S4: Form a gas diffusion structure 30A, at least a portion of which penetrates the first electrolyte layer 11 along the first direction Z, and the gas diffusion structure 30A comprises a porous material.

[0148] Step S4 may include the following steps: 1) forming a gas channel, at least a portion of which penetrates the first electrolyte layer 11 along the first direction Z; 2) filling the gas channel with a slurry, the highest point of which is higher than the upper surface of the first electrolyte layer 11; 3) forming the gas diffusion structure 30A by drying and sintering, the upper surface of which is flush with the upper surface of the first electrolyte layer 11.

[0149] For a specific example, a dispensing machine or a micro-syringe can be used to fill the gas channels with porous slurry. The top of the slurry is arc-shaped, with its highest point extending 0.1 mm to 0.5 mm above the first solid electrolyte layer, and the angle between its arc surface and the first electrolyte layer 11 is 45° to 90°. The shape of the arc, including the height of the highest point and the angle of the arc surface, can be controlled by the amount of slurry used.

[0150] The solid content in the porous slurry can be between 50 wt% and 60 wt%, with the remainder being organic components, including binders, plasticizers, and solvents. The particle size of the solid ceramic particles can range from 2 μm to 5 μm.

[0151] The product can be dried at 80℃~100℃ for 2h~4h, and then sintered in a furnace at 1100℃~1200℃ for 2h~3h. The sintering shrinkage rate of the slurry at 1100℃~1200℃ can be 1%~5%.

[0152] The gas sensor fabrication method provided in this application provides a gas sensor comprising a gas diffusion structure, which includes a porous material. The porous material can adsorb pollutants and impurity particles in the exhaust gas, thereby reducing the entry of pollutants and impurity particles into the diffusion barrier structure and thus reducing the risk of blockage of the diffusion barrier structure.

[0153] Please see Figure 7-9 , Figure 7 This is an exploded structural diagram of a heating unit provided in some embodiments of this application. Figure 8 This is provided by some embodiments of this application. Figure 7 A schematic diagram of the structure of the first heterogeneous bonding layer at position A. Figure 9 This is provided by some embodiments of this application. Figure 7 A cross-sectional view of the first insulating layer, the first heterogeneous bonding layer and the first reinforcing layer along the first direction and the third direction.

[0154] The heating unit 40A includes a heating electrode 41, a first insulating layer 421 and a second insulating layer 422 located on both sides of the heating electrode 41, a first sub-electrolyte layer 431 located on the side of the first insulating layer 421 away from the heating electrode 41, and a second sub-electrolyte layer 432 located on the side of the second insulating layer 422 away from the heating electrode 41. The heating unit 40A also includes a first heterogeneous bonding layer 44, located between the first insulating layer 421 and the first sub-electrolyte layer 431. The first heterogeneous bonding layer 44 includes a first bonding portion 441 and a second bonding portion 442 connected in the same layer. The first bonding portion 441 is made of the same material as the first insulating layer 421, and the second bonding portion 442 is made of the same material as the first sub-electrolyte layer 431. Because the first bonding portion 441 and the second bonding portion 442 are connected in the same layer and are independent of each other, and the first bonding portion 441 and the first insulating layer 421 are made of the same material and have contacting surfaces, the bonding force between the first bonding portion 441 and the first insulating layer 421 is greatly improved. Since the second bonding portion 442 and the first sub-electrolyte layer 431 are made of the same material and have surfaces in contact with each other, the bonding force between the second bonding portion 442 and the first sub-electrolyte layer 431 is greatly improved. Therefore, the first heterogeneous bonding layer 44 can greatly improve the bonding strength between the first insulating layer 421 and the first sub-electrolyte layer 431.

[0155] The material of the first sub-electrolyte layer 431 may include zirconium oxide and additives, such as yttrium oxide, cerium oxide, or calcium oxide, wherein zirconium oxide may be a high-density material to provide greater hardness. The material of the first insulating layer 421 may include aluminum oxide or aluminum nitride, wherein aluminum oxide or aluminum nitride may be a high-density material to provide greater hardness.

[0156] In some embodiments, the content of the additive in the first sub-electrolyte layer 431 is 5 mol% to 10 mol%, which can make the first sub-electrolyte layer 431 have a tetragonal crystal form, good conductivity, and moderate cost.

[0157] The thickness of the first heterojunction layer 44 along the third direction Z can be less than the thickness of the first sub-electrolyte layer 431 along the third direction Z, where the third direction Z is the stacking direction of the first sub-electrolyte layer 431 and the first insulating layer 421. Setting the thickness of the first heterojunction layer 44 to be less than the thickness of the first sub-electrolyte layer 431 can reduce the number of printing operations required for the first heterojunction layer 44, thereby reducing costs, and can also reduce the impact of the first heterojunction layer 44 on the heat transfer efficiency along the third direction Z.

[0158] In some embodiments, the thickness of the first sub-electrolyte layer 431 along the third direction Z is 150 micrometers to 300 micrometers. The thickness of the first heterojunction layer 44 along the third direction Z is 10 micrometers to 50 micrometers. A thickness greater than or equal to 10 micrometers can ensure that the first heterojunction layer 44 improves the bonding strength between the first insulating layer 421 and the first sub-electrolyte layer 431. A thickness less than or equal to 50 micrometers can not only further reduce costs, but also further reduce the impact of the first heterojunction layer 44 on the heat transfer efficiency in the third direction Z.

[0159] See back Figure 2 and Figure 4 The thickness of the first electrolyte layer 11, the second electrolyte layer 21, the third electrolyte layer 22, the fourth electrolyte layer 28, and the fifth electrolyte layer 43 along the third direction Z can all be 300 micrometers to 500 micrometers.

[0160] In some embodiments, the thickness of the first insulating layer 421 along the third direction Z is 10 micrometers to 50 micrometers, and the thickness of the second insulating layer 422 along the third direction Z is 10 micrometers to 50 micrometers. The thickness of the detection unit along the third direction Z is 10 micrometers to 20 micrometers.

[0161] like Figure 7 As shown, the first sub-electrolyte layer 431 can serve as a carrier to provide support for other structures. The first heterogeneous bonding layer 44, the first insulating layer 421, the heating electrode 41, and the second insulating layer 422 are sequentially stacked on the first sub-electrolyte layer 431. The first insulating layer 421 and the second insulating layer 422 can be made of the same material, and the first sub-electrolyte layer 431 and the second sub-electrolyte layer 432 can also be made of the same material.

[0162] The heating unit 40A may further include a second heterogeneous bonding layer 45, which is located between the second insulating layer 422 and the second sub-electrolyte layer 432. The second heterogeneous bonding layer 45 includes a third bonding portion and a fourth bonding portion connected in the same layer. The third bonding portion is made of the same material as the second insulating layer 422, and the fourth bonding portion is made of the same material as the second sub-electrolyte layer 432, thus greatly improving the bonding strength between the second insulating layer 422 and the second sub-electrolyte layer 432.

[0163] The thickness of the second heterojunction layer 45 along the third direction Z can be less than the thickness of the second sub-electrolyte layer 432 along the third direction Z. Setting the thickness of the second heterojunction layer 45 to be less than the thickness of the second sub-electrolyte layer 432 can reduce the number of printing operations required for the second heterojunction layer 45, thereby reducing costs, and can also reduce the impact of the second heterojunction layer 45 on the heat transfer efficiency in the third direction Z.

[0164] In some embodiments, the thickness of the second sub-electrolyte layer 432 along the third direction Z is 150 micrometers to 300 micrometers. The thickness of the second heterojunction layer 45 along the third direction Z is 10 micrometers to 50 micrometers. A thickness greater than or equal to 10 micrometers can improve the bonding strength between the second insulating layer 422 and the second sub-electrolyte layer 432. A thickness less than or equal to 50 micrometers can not only further reduce costs but also further reduce the impact of the second heterojunction layer 45 on the heat transfer efficiency in the third direction Z.

[0165] Please see Figure 10 , Figure 10 This is an exploded structural diagram of a heating unit provided in some embodiments of this application. For ease of understanding and brief explanation, the same structures as those in the above embodiments will continue to use the same reference numerals, and the same structures will not be described in detail. This embodiment will only describe the different structures in detail.

[0166] The heating unit 40B may further include a first reinforcing layer 46, which is located between the first heterogeneous bonding layer 44 and the first sub-electrolyte layer 431, and the first reinforcing layer 46 and the first sub-electrolyte layer 431 are made of the same material. Therefore, during the bonding process, the first reinforcing layer 46 can wet the first heterogeneous bonding layer 44 and the first sub-electrolyte layer 431, thereby enhancing the bonding strength between the first heterogeneous bonding layer 44 and the first sub-electrolyte layer 431.

[0167] The heating unit 40B may further include a second reinforcing layer 47, which is located between the second heterogeneous bonding layer 45 and the second sub-electrolyte layer 432, and the second reinforcing layer 47 and the second sub-electrolyte layer 432 are made of the same material. Therefore, during the bonding process, the second reinforcing layer 47 can wet the second heterogeneous bonding layer 45 and the second sub-electrolyte layer 432, thereby strengthening the second heterogeneous bonding layer 45 and the second sub-electrolyte layer 432.

[0168] In some embodiments, the first reinforcing layer 46 and the second reinforcing layer 47 can effectively wet the first sub-electrolyte layer 431 and the second sub-electrolyte layer 432 during the screen printing process, allowing the two electrolyte substrates to make better contact during the pressing process, thereby promoting the improvement of the sintering bond strength between the electrolyte substrates. In addition, since the reinforcing layer and the electrolyte substrate are made of the same material, they can promote the bonding between the electrolyte substrates during the sintering process, thereby increasing the density at the electrolyte substrate bonding site.

[0169] The top view areas of the first sub-electrolyte layer 431, the first reinforcing layer 46, the second reinforcing layer 47, and the second sub-electrolyte layer 432 are equal and larger than the top view areas of other film layers (including the heating unit). Therefore, the first reinforcing layer 46 and the second reinforcing layer 47 can contact each other during the sintering process. The "top view" refers to the top view along a third direction Z, where Z is the stacking direction of the first sub-electrolyte layer 431 and the first insulating layer 421.

[0170] In some embodiments, the thickness of the first reinforcing layer 46 along the third direction Z is less than the thickness of the first sub-electrolyte layer 431 in the third direction Z. Therefore, while using the first reinforcing layer 46 to enhance the bonding strength between the first heterogeneous bonding layer 44 and the first sub-electrolyte layer 431, the heat transfer efficiency in the third direction Z can be controlled within an acceptable range, and the printing cost can be reduced.

[0171] In some embodiments, the thickness of the first reinforcing layer 46 in the third direction Z is 10 micrometers to 50 micrometers, which can ensure that the first reinforcing layer 46 enhances the bonding strength between the first heterogeneous bonding layer 44 and the first sub-electrolyte layer 431, further reduce the impact of the first reinforcing layer 46 on the heat transfer efficiency in the third direction Z, and further reduce printing costs.

[0172] See Figure 8 In some embodiments, at least a portion of the first bonding portion 441 is disposed around at least a portion of the second bonding portion 442, and / or at least a portion of the second bonding portion 442 is disposed around at least a portion of the first bonding portion 441. This can increase the contact area between the first bonding portion 441 and the second bonding portion 442, improve the bonding strength between them, and reduce delamination or breakage, thereby facilitating the bonding between the first insulating layer 421 and the first sub-electrolyte layer 431.

[0173] like Figure 8 As shown, the first joint 441 includes a first connecting portion 4411 and at least two first intersecting portions 4412, with the first connecting portion 4411 connecting the at least two first intersecting portions 4412; the second joint 442 includes a second connecting portion 4421 and at least two second intersecting portions 4422, with the second intersecting portions 4422 connecting the at least two second intersecting portions 4422. Two adjacent first intersecting portions 4412 and first connecting portions 4411 are arranged around one second intersecting portion 4422, and two adjacent second intersecting portions 4422 and second connecting portions 4421 are arranged around one first intersecting portion 4412.

[0174] like Figure 8As shown, the first sub-electrolyte layer 431 extends along a first direction Y. The first connecting portion 4411 and the second connecting portion 4421 are disposed opposite each other in the second direction X and both extend along the first direction Y. The first intersecting portion 4412 and the second intersecting portion 4422 are alternately disposed along the first direction Y and both extend along the second direction X, and the first direction Y intersects the second direction X. In one embodiment, the first direction Y and the second direction X may be perpendicular to each other and both are perpendicular to a third direction Z.

[0175] Figure 9 The cross-sectional structure of the first insulating layer 421, the first heterogeneous bonding layer 44, and the first reinforcing layer 46 is shown, wherein the first cross portion 4412 and the second cross portion 4422 are arranged alternately along the first direction Y.

[0176] In other embodiments, the first sub-electrolyte layer 431 extends along a first direction Y, the first connecting portion 4411 and the second connecting portion 4421 are arranged opposite to each other in the first direction Y and are parallel to each other and both extend along a second direction X, the first intersecting portion 4412 and the second intersecting portion 4422 are alternately arranged along the second direction X and both extend along the first direction Y, and the first direction Y intersects the second direction X.

[0177] In some embodiments, such as Figure 8 As shown, the first cross portion 4412 has a first end 4412A and a second end 4412B. The first end 4412A is connected to the first connecting portion 4411, and the second end 4412B is connected to the second connecting portion 4421. The second cross portion 4422 has a third end 4422A and a fourth end 4422B. The third end 4422A is connected to the second connecting portion 4421, and the fourth end 4422B is connected to the first connecting portion 4411. This cross-composite structure can effectively mitigate the problem of inconsistent sintering shrinkage rates between the first insulating layer 421 and the first sub-electrolyte layer 431, and increase the contact area between the first bonding portion 441 and the second bonding portion 442, thereby improving the bonding force between the two. As a result, the gas sensor 100 has excellent sealing performance and bending strength.

[0178] In some embodiments, the top view area of ​​the first joint portion 441 along the third direction Z is 20% to 80% of the top view area of ​​the first heterogeneous bonding layer 44 along the third direction Z. When the first joint portion 441 and the second joint portion 442 include the first connecting portion 4411 and the second connecting portion 4421, the area ratio of the first joint portion 441 is 20% to 80%, which can allow the first joint portion 441 and the second joint portion 442 to have an intersection to form an intersecting structure, thereby increasing the contact area between the two and improving the bonding force.

[0179] The first heterogeneous bonding layer 44 provided in this application has a cross-tooth structure, and the second bonding portion 442 and the first bonding portion 441 form an S-shaped contact, which increases the contact area between the second bonding portion 442 and the first bonding portion 441, making the engagement between the first bonding portion 441 and the second bonding portion 442 more compact, so that the second bonding portion 442 and the first bonding portion 441 are less likely to crack and delaminate due to stress accumulation.

[0180] Please see Figure 11 , Figure 11 This is a schematic diagram of the connection structure of the first joint and the second joint provided in some embodiments of this application.

[0181] The first joint 441 includes a plurality of first sub-joints 4410, and the second joint 442 includes a plurality of second sub-joints 4420. The plurality of first sub-joints 4410 and the plurality of second sub-joints 4420 are alternately arranged around each other, which can also increase the contact area between the first joint 441 and the second joint 442.

[0182] In a specific example, the first heterogeneous bonding layer 44 consists of a first sub-bonding portion 4410, a second sub-bonding portion 4420, a first sub-bonding portion 4410, and a second sub-bonding portion 4420 from the inside out. Alternatively, the first heterogeneous bonding layer 44 can also consist of a second sub-bonding portion 4420, a first sub-bonding portion 4410, a second sub-bonding portion 4420, and a first sub-bonding portion 4410 from the inside out.

[0183] In some embodiments, the top view shape of the first sub-joint portion 4410 and / or the second sub-joint portion 4420 along the third direction Z is a U-shape. For example... Figure 6 As shown, the top view of one first sub-joint 4410 is rectangular, the top view of another first sub-joint 4410 is square, and the top view of both second sub-joints 4420 is square.

[0184] Referring to Table 1, Examples 1-6 and Comparative Examples 1-3 were designed.

[0185] The product of Example 1 includes Figure 10The heating unit 40B includes a reinforcing layer (including a first reinforcing layer 46 and a second reinforcing layer 47) and a heterogeneous bonding layer (including a first heterogeneous bonding layer 44 and a second heterogeneous bonding layer 45). The first heterogeneous bonding layer 44 has a thickness of 20 micrometers, and the second heterogeneous bonding layer 45 has the same thickness as the first heterogeneous bonding layer 44. The area ratio of the first bonding portion 441 in the first heterogeneous bonding layer 44 is 50%, and the area ratio of the third bonding portion in the second heterogeneous bonding layer 45 is the same as the area ratio of the first bonding portion 441 in the first heterogeneous bonding layer 44. The first reinforcing layer 46 has a thickness of 20 micrometers, and the second reinforcing layer 47 has the same thickness as the first reinforcing layer 46.

[0186] Example 2

[0187] There is no reinforcing layer (i.e., the thickness of both the first reinforcing layer 46 and the second reinforcing layer 47 is 0), and other structural features are the same as in Example 1.

[0188] Example 3

[0189] Unlike Embodiment 1, the area ratio of the first bonding portion 441 in the first heterogeneous bonding layer 44 is 20%, and the area ratio of the third bonding portion in the second heterogeneous bonding layer 45 is 20%. Other structural features are the same as in Embodiment 1.

[0190] Example 4

[0191] Unlike Embodiment 1, the area ratio of the first bonding portion 441 in the first heterogeneous bonding layer 44 is 80%, and the area ratio of the third bonding portion in the second heterogeneous bonding layer 45 is 80%. Other structural features are the same as in Embodiment 1.

[0192] Example 5

[0193] Unlike Example 1, the thickness of the first heterogeneous bonding layer 44 and the second heterogeneous bonding layer 45 is 10 micrometers, while other structural features are the same as in Example 1.

[0194] Example 6

[0195] Unlike Example 1, the thickness of the first heterogeneous bonding layer 44 and the second heterogeneous bonding layer 45 is 50 micrometers, while other structural features are the same as in Example 1.

[0196] Comparative Example 1

[0197] No reinforcing layer or heterogeneous bonding layer was prepared; other structural features were the same as in Example 1.

[0198] Comparative Example 2

[0199] No heterogeneous bonding layer was prepared; other structural features were the same as in Example 1.

[0200] Comparative Example 3

[0201] The structure prepared using the preparation process described in CN102235994B has a transition layer consisting of a simple mixture of zirconium oxide, aluminum oxide, and calcium oxide.

[0202] Table 1

[0203]

[0204] Performance tests were conducted on the above embodiments and comparative examples. The performance test methods are as follows:

[0205] 1. Bending strength test: The bending strength test is conducted in accordance with GB / T6569-2006 Test Method for Bending Strength of Fine Ceramics.

[0206] 2. Thermal shock resistance test: Apply 12V DC power to the heater of the product to make the product heat up rapidly, maintain the temperature for 1 minute, then turn off the power and let the product cool down naturally for 1 minute. This is one hot and cold cycle, and one record is made for one cycle.

[0207] The test results are shown in Table 2 below. From the data in Table 2, it can be seen that using… Figure 10 Compared to the product in the comparative example, the heating unit 40B in this example shows significant improvements in crack yield, flexural strength, and thermal shock resistance. Furthermore, a comparison of Example 1 and Example 2 shows that the product with the reinforcing layer performs better than the product without the reinforcing layer.

[0208] Table 2

[0209]

[0210]

[0211] Please see Figure 12 , Figure 12 This is a top view schematic diagram of the heating electrode provided in some embodiments of this application.

[0212] The heating electrode 41A extends along a first direction (Y) and includes a heating section 411, a buffer section 412, and a lead section 413 arranged along the first direction Y. The buffer section 412 is located between the heating section 411 and the lead section 413, and the resistance of the buffer section 412 is less than the resistance of the heating section 411 but greater than the resistance of the lead section 413. This application adds a buffer section 412 between the heating section 411 and the lead section 413. Since the resistance of the buffer section 412 is greater than the total resistance of the lead section 413 but less than the total resistance of the heating section 411, the heat generated by the buffer section 412 is greater than the heat generated by the lead section 413 but less than the heat generated by the heating section 411. Therefore, the temperature of the buffer section 412 is greater than the temperature of the lead section 413 but less than the temperature of the heating section 411. This reduces the temperature gradient between the heating section 411 and the lead section 413, thereby reducing the product failure rate.

[0213] In some embodiments, the total resistance of the heating part 411 is 55% to 65% of the total resistance of the heating electrode 41A, the total resistance of the buffer part 412 is 15% to 30% of the total resistance of the heating electrode 41A, and the total resistance of the lead part 413 is 15% to 30% of the total resistance of the heating electrode 41A. Therefore, the temperature of the heating part 411 can be 400°C to 800°C, the temperature of the buffer part 412 can be 200°C to 800°C, and the temperature of the lead part 413 can be less than 200°C.

[0214] In some embodiments, such as Figure 12 As shown, the lead wire portion 413 mainly serves as a conductor. The dimension of the lead wire portion 413 along the first direction Y is greater than the dimension of the heating portion 411 along the first direction Y, and the dimension of the lead wire portion 413 along the first direction Y is greater than the dimension of the buffer portion 412 along the first direction Y.

[0215] In some embodiments, the resistivity of the lead portion 413 is low, serving only a conductive function and generating almost no heat. This design saves energy consumption and also protects the external connector located at the tail of the heating electrode 41A. The external connector connects the external power supply to the heating electrode 41A. The metal spring in the connector is typically made of copper and has an external plastic protective shell. Therefore, the temperature at the tail of the heating electrode 41A needs to be kept low to prevent the connector from being burned or damaged.

[0216] In some embodiments, the resistivity of the buffer portion 412 may be set to be greater than that of the lead portion 413, such that the buffer portion 412 has a larger resistance than the lead portion 413 in the case of a smaller length (dimension along the first direction).

[0217] The heating section 411 may further include a plurality of sub-heating sections 4111 arranged along the first direction Y, and the plurality of sub-heating sections 4111 are connected in series end to end. The opposite ends of two adjacent sub-heating sections 4111 are connected by a bend, and this meandering shape can increase the overall length of the heating section 411, thereby increasing the resistance of the heating section 411 and making the heat field uniform within the heating range where the heating section 411 is located.

[0218] In some embodiments, the dimension of the heating part 411 along the first direction Y is greater than or equal to the dimension of the buffer part 412 along the first direction Y. Therefore, the actual length of the heating part 411 is greater than the actual length of the buffer part 412. Thus, the resistivity of the buffer part 412 can be set to be less than or equal to the resistivity of the heating part 411, so that the resistance of the heating part 411 is greater than the resistance of the buffer part 412. Here, "actual length" refers to the length along the current flow direction after series connection.

[0219] In some embodiments, the dimension of the buffer portion 412 along the first direction Y is 50% to 100% of the dimension of the heating portion 411 along the first direction Y. It is understood that the dimension range of the buffer portion 412 along the first direction can be set according to the required proportion of the total resistance of the buffer portion 412 to the total resistance of the heating electrode.

[0220] In a specific example, the dimensions of the heating part 411 along the first direction Y and the dimensions of the buffer part 412 along the first direction Y are both equal to 4 mm.

[0221] In some embodiments, since the actual length of the buffer portion 412 is less than the actual length of the heating portion 411, the resistivity of the buffer portion 412 can be set to be less than or equal to the resistivity of the heating portion 411, so as to control the total resistance of the buffer portion 412 to be less than the total resistance of the heating portion 411.

[0222] In one embodiment, the resistivity of the buffer portion 412 is less than that of the heating portion 411, where the resistivity of the heating portion 411 is 35 μΩ·cm to 50 μΩ·cm, and the resistivity of the buffer portion 412 is 10 μΩ·cm to 25 μΩ·cm. It is understood that the resistivity of each portion can be set according to the required total resistance.

[0223] In one embodiment, the resistivity of the buffer portion 412 can be set to be equal to the resistivity of the heating portion 411, so that the buffer portion 412 and the heating portion 411 can be made of the same material, thereby reducing the manufacturing process and cost.

[0224] like Figure 12As shown, the lead portion 413 may include a first sub-lead portion 4131 and a second sub-lead portion 4132 disposed opposite to each other in a second direction X, wherein the second direction X is perpendicular to the first direction Y. The buffer portion 412 includes a first sub-buffer portion 4121 connected to the first sub-lead portion 4131 and a second sub-buffer portion 4122 connected to the second sub-lead portion 4132. The heating portion 411 includes a first end 4111 connected to the first sub-buffer portion 4121 and a second end 4112 connected to the second sub-buffer portion 4122. Thus, the first sub-lead portion 4131, the first sub-buffer portion 4121, the first end 4111, the second end 4112, the second sub-buffer portion 4122, and the second sub-lead portion 4132 can be connected in series to achieve the heating function.

[0225] The first sub-buffer section 4121 gradually increases in size along the second direction X from the first end 4111 to the first sub-lead section 4131 (the direction in the diagram is from left to right), and the second sub-buffer section 4122 gradually increases in size along the second direction X from the second end 4112 to the second sub-lead section 4132 (the direction in the diagram is from left to right). This results in different resistances at different locations within the buffer section 412, with the resistance gradually decreasing from left to right. Consequently, the temperature gradually decreases from left to right, allowing for a gradual temperature transition within the buffer section 412 and helping to alleviate the concentration of thermal stress.

[0226] Through experimental fitting, the temperature changes at various locations within the buffer section 412 were obtained as shown in the following formula:

[0227]

[0228] Where T1 is the temperature at the junction of the buffer section 412 and the heating section 411, T2 is the temperature at a distance L from the junction of the buffer section 412 and the heating section 411, and a is a constant with a value ranging from 0.5 to 5. It can be seen that the further away the buffer section 412 is from the heating section 411, the lower the temperature.

[0229] In some embodiments, the dimensions of the first sub-lead portion 4131 and the second sub-lead portion 4132 along the second direction X are uniform, and the dimensions of the first sub-lead portion 4131 and the second sub-lead portion 4132 along the second direction X may be the same.

[0230] The minimum dimension W1 (left end dimension) of the first sub-buffer section 4121 along the second direction X is equal to the dimension W1 of the first end 4111 along the second direction X, and the maximum dimension W2 (right end) of the first sub-buffer section 4121 along the second direction X is equal to the dimension W2 of the first sub-lead section 4131 along the second direction X. That is, the first sub-buffer section 4121 is directly connected to the first sub-lead section 4131 and the first end 4111.

[0231] The heating electrode 41A has a symmetrical axis extending along the first direction Y, and the first sub-buffer portion 4121 and the second sub-buffer portion 4122 are symmetrical about the symmetrical axis. Therefore, the minimum dimension W1 (left end dimension) of the second sub-buffer portion 4122 along the second direction X is equal to the dimension of the second end 4112 along the second direction X, and the maximum dimension W2 (right end) of the second sub-buffer portion 4122 along the second direction X is equal to the dimension of the second sub-lead portion 4132 along the second direction X.

[0232] In some embodiments, the first sub-buffer portion 4121 has a first outer side surface 4121O that is away from the second sub-buffer portion 4122, and the heating portion 411 has a second outer side surface 4111O that is connected to the first outer side surface 4121O.

[0233] In one embodiment, such as Figure 12 As shown, the first outer surface 4121O and the second outer surface 4111O extend in the first direction Y, that is, the first outer surface 4121O and the second outer surface 4111O are on the same plane.

[0234] In another embodiment, the first outer surface 4121O is located on the side of the second outer surface 4111O close to the second sub-buffer portion 4122.

[0235] In some embodiments, the first sub-buffer portion 4121 has an inner side surface 4121I near the second sub-buffer portion 4122, and the inner side surface 4121I is a flat surface.

[0236] Please see Figure 13 , Figure 13 This is a top view schematic diagram of the heating electrode provided in some embodiments of this application. For ease of understanding and brief explanation, the same structures as those in the above embodiments will continue to use the same reference numerals, and the same structures will not be described in detail. This embodiment will only describe the different structures in detail.

[0237] This embodiment and Figure 12The difference in the embodiments is that the maximum dimension W2 (right end) of the first sub-buffer portion 4121 along the second direction X in the heating electrode 41B is smaller than the dimension W3 of the first sub-lead portion 4131 along the second direction X, and the maximum dimension (right end) of the second sub-buffer portion 4122 along the second direction X is smaller than the dimension of the second sub-lead portion 4132 along the second direction X. Therefore, a transition portion can be provided to transition the size change between the first sub-buffer portion 4121 and the first sub-lead portion 4131, and to transition the size change between the second sub-buffer portion 4122 and the second sub-lead portion 4132.

[0238] In some embodiments, the heating electrode 41B further includes a transition portion 414, which includes a first sub-transition portion connected between the first sub-buffer portion 4121 and the first sub-lead portion 4131, and a second sub-transition portion connected between the second sub-buffer portion 4122 and the second sub-lead portion 4132. The size of the first sub-transition portion gradually increases along the second direction X from the first sub-buffer portion 4121 to the first sub-lead portion 4131 (illustrated from left to right), and the size of the second sub-transition portion gradually increases along the second direction X from the second sub-buffer portion 4122 to the second sub-lead portion 4132 (illustrated from left to right).

[0239] It is understood that the minimum dimension (left end dimension) of the first sub-buffer portion 4121 along the second direction X can also be greater than the dimension of the first end 4111 along the second direction X. Specifically, a transition portion can be provided between the first sub-buffer portion 4121 and the first end 4111.

[0240] Please see Figure 14 , Figure 14 This is a top view schematic diagram of the heating electrode provided in some embodiments of this application. For ease of understanding and brief explanation, the same structures as those in the above embodiments will continue to use the same reference numerals, and the same structures will not be described in detail. This embodiment will only describe the different structures in detail.

[0241] This embodiment and Figure 13 The difference in the embodiments is that the first sub-buffer portion 4121 in the heating electrode 41C has an inner side surface 4121I near the second sub-buffer portion 4122, the inner side surface 4121I is a stepped surface, and the resistance of the first sub-buffer portion 4121 is different at each step.

[0242] The heating electrode provided in this application extends along a first direction Y and includes a heating portion 411, a buffer portion 412, and a lead portion 413 arranged along the first direction Y. The buffer portion 412 is located between the heating portion 411 and the lead portion 413, and the total resistance of the buffer portion 412 is less than the total resistance of the heating portion 411 but greater than the total resistance of the lead portion 413. By adding a buffer portion 412 between the heating portion 411 and the lead portion 413, and the total resistance of the buffer portion 412 being greater than the total resistance of the lead portion 413 but less than the total resistance of the heating portion 411, the heat generated by the buffer portion 412 is greater than the heat generated by the lead portion 413 but less than the heat generated by the heating portion 411. Therefore, the temperature of the buffer portion 412 is greater than the temperature of the lead portion 413 but less than the temperature of the heating portion 411. This reduces the temperature gradient between the heating portion 411 and the lead portion 413, thereby reducing the product failure rate.

[0243] The present application provides the following embodiments 7-11 and comparative example 4 to illustrate the advantages of the products in the embodiments of the present application.

[0244] Example 7

[0245] The product uses an attached Figure 12 The heating electrode structure shown has a dimension of 4 mm for both the heating part along the first direction and the buffer part along the first direction.

[0246] Example 8

[0247] The product uses an attached Figure 13 The heating electrode structure shown has a dimension of 4 mm for both the heating part along the first direction and the buffer part along the first direction.

[0248] Example 9

[0249] In this embodiment, except for the size of the buffer section, the other features of the product are the same as those in Embodiment 7 (for example, the size of the heating section along the first direction is 4 mm, and the size of the buffer section along the first direction is 3 mm).

[0250] Example 10

[0251] In this embodiment, except for the size of the buffer section, the other features of the product are the same as those in Embodiment 7 (for example, the size of the heating section along the first direction is 4 mm, and the size of the buffer section along the first direction is 2 mm).

[0252] Example 11

[0253] In this embodiment, except for the size of the buffer section, the other features of the product are the same as those in Embodiment 7 (for example, the size of the heating section along the first direction is 4 mm, and the size of the buffer section along the first direction is 1 mm).

[0254] Comparative Example 4

[0255] Except for the absence of a buffer section, the product features are the same as those in Example 7.

[0256] Thermal shock resistance tests were conducted on the products provided in the above embodiments and comparative examples: 12V DC power was applied to the heater of the product to rapidly heat the product, and the power was cut off after 1 minute. The product was allowed to cool naturally for 1 minute. This constitutes one hot and cold cycle, and one cycle was recorded once.

[0257] After the thermal shock resistance test, the internal resistance of the oxygen sensor was measured. If the internal resistance exceeded the 5% variation range, it was determined that the solid electrolyte of the oxygen sensor had cracked. The number of times the power was switched on and off when the crack occurred was recorded, which is the effective number of thermal shock resistance tests of the oxygen sensor. The results are shown in Table 3 below.

[0258] As shown in Table 3, setting up a buffer section can increase the effective number of thermal shock resistance cycles of the product. When the size of the buffer section along the first direction differs significantly from the size of the heating section along the first direction, the effective number of thermal shock resistance cycles of the product decreases. The smaller the difference between the size of the buffer section along the first direction and the size of the heating section along the first direction, the greater the effective number of thermal shock resistance cycles of the product.

[0259] Table 3

[0260] Effective number of thermal shocks / times Example 7 ＞5000 Example 8 ＞5000 Example 9 ＞5000 Example 10 ＞4500 Example 11 ＜4000 Comparative Example 4 ＜3000

[0261] This application provides a gas monitoring device, which includes the gas sensor described above. The gas monitoring device has all the beneficial effects of the gas sensor described above, which will not be repeated here.

[0262] This application provides a vehicle that includes the aforementioned gas monitoring device, and the vehicle possesses all the beneficial effects of the aforementioned gas monitoring device, which will not be elaborated further here. This gas monitoring device can be applied to vehicle exhaust gas monitoring.

[0263] The vehicle may be a gasoline-powered vehicle, a plug-in hybrid electric vehicle, or a new energy vehicle, etc., and this disclosure does not make any specific restrictions.

[0264] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0265] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0266] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0267] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A gas sensor, characterized by, The application relates to a pump unit, a detection unit and a gas diffusion structure. The pump unit comprises a first electrolyte layer, a first electrode and a second electrode, the first electrode and the second electrode are respectively located on two sides of the first electrolyte layer along a first direction, and the first direction is perpendicular to the surface of the first electrolyte layer. The detection unit comprises a diffusion barrier structure and a detection cavity which are connected to each other, and the second electrode is connected to the detection cavity. The gas diffusion structure is at least partially penetrated through the first electrolyte layer along the first direction, and is connected to the diffusion barrier structure, and the gas diffusion structure comprises a porous material.

2. The gas sensor according to claim 1, characterized by The gas diffusion structure and the diffusion barrier structure are both porous materials, the porosity of the gas diffusion structure is greater than the porosity of the diffusion barrier structure, and / or the pore size of the gas diffusion structure is greater than the pore size of the diffusion barrier structure.

3. The gas sensor according to claim 2, characterized in that, The porosity of the gas diffusion structure is 45% to 70%, and the porosity of the diffusion barrier structure is 20% to 40%.

4. The gas sensor according to claim 2, characterized by The pore size of the gas diffusion structure is 5 microns to 10 microns, and the pore size of the diffusion barrier structure is 0.1 micron to 2 microns.

5. The gas sensor according to claim 2, characterized by The porous material comprises porous zirconium oxide and / or porous aluminum oxide.

6. The gas sensor according to claim 2, characterized by The gas diffusion structure further comprises a noble metal, and the mass fraction of the noble metal in the gas diffusion structure is 0.1% to 0.5%.

7. The gas sensor according to claim 1, characterized by The detection unit further comprises a second electrolyte layer and a third electrolyte layer, and the second electrolyte layer is located between the first electrolyte layer and the third electrolyte layer. The diffusion barrier structure and the detection cavity are arranged in the second electrolyte layer.

8. The gas sensor according to claim 7, characterized by The diffusion barrier structure is penetrated through the second electrolyte layer along the first direction, and is located between the first electrolyte layer and the third electrolyte layer.

9. The gas sensor according to claim 7, characterized by The gas diffusion structure has opposite first and second end faces, the first end face is higher than or flush with the side of the first electrolyte layer away from the second electrolyte layer.

10. The gas sensor according to claim 9, characterized by The gas diffusion structure is located in the first electrolyte layer, and the second end face is connected to the diffusion barrier structure.

11. The gas sensor according to claim 7, characterized by The gas diffusion structure further extends into the diffusion barrier structure along the first direction, and the size of the gas diffusion structure along the first direction is greater than or equal to the sum of the sizes of the first electrolyte layer and the second electrolyte layer along the first direction.

12. The gas sensor according to claim 1, characterized by The orthogonal projection of the gas diffusion structure on the first electrolyte layer is located in the range of the orthogonal projection of the diffusion barrier structure on the first electrolyte layer.

13. The gas sensor according to claim 12, characterized in that The central axis of the gas diffusion structure along the first direction coincides with the central axis of the diffusion barrier structure along the first direction.

14. The gas sensor according to claim 1, characterized by The orthogonal projection of the detection cavity on the first electrolyte layer coincides with the orthogonal projection of the second electrode on the first electrolyte layer.

15. A gas sensor according to claim 14, characterised in that, The detection cavity and the second electrode are both arranged around the diffusion barrier structure.

16. The gas sensor according to claim 7, characterized by The detection unit further comprises a fourth electrolyte layer and a third electrode, and the fourth electrolyte layer and the third electrode are both located on the side of the third electrolyte layer away from the second electrolyte layer. The fourth electrolyte layer is provided with a standard gas channel, and the standard gas channel is connected with the third electrode.

17. A gas sensor according to claim 16, characterised in that The detection unit further comprises a fourth electrode, which is located on the side of the third electrolyte layer close to the second electrolyte layer. The fourth electrode has a projection on the first electrolyte layer, which coincides with the projection of the detection cavity on the first electrolyte layer.

18. The gas sensor according to claim 7, characterized by The detection cavity and the second electrode are both connected to one side of the diffusion barrier structure and are arranged along a second direction, which is parallel to the surface of the first electrolyte layer and perpendicular to the first direction.

19. A gas sensor according to claim 18, characterised in that, The detection unit further comprises a third electrode, which is located on the side of the first electrolyte layer away from the first electrode and is arranged separately from the second electrode. The second electrolyte layer is further provided with a standard gas channel, which is connected with the third electrode and is arranged separately from the detection cavity.

20. A gas sensor according to claim 19, characterised in that, The detection unit further comprises a fourth electrode, which is located on the side of the third electrolyte layer close to the second electrolyte layer. The fourth electrode comprises a first electrode part, a second electrode part and a third electrode part connected in sequence in a third direction, the projection of the first electrode part on the first electrolyte layer coincides with the detection cavity, the second electrode part is located between part of the second electrolyte layer and the third electrolyte layer, and the third electrode part has part of the second electrolyte layer between it and the standard gas channel.

21. The gas sensor of claim 1, wherein Further comprising a heating unit located on the side of the detection unit away from the pump unit, the heating unit comprising a heating electrode, an insulation layer surrounding the heating electrode, and a fifth electrolyte layer surrounding the insulation layer.

22. The gas sensor of claim 1, wherein Further comprising a heating unit located on the side of the detection unit away from the pump unit, the heating unit comprising a heating electrode, a first insulation layer and a second insulation layer located on both sides of the heating electrode respectively, a first sub-electrolyte layer located on the side of the first insulation layer away from the heating electrode, and a second sub-electrolyte layer located on the side of the second insulation layer away from the heating electrode; the heating unit further comprises: A first heterojunction layer is located between the first insulation layer and the first sub-electrolyte layer, and the first heterojunction layer comprises a first junction part and a second junction part connected in the same layer, the first junction part has the same material as the first insulation layer, and the second junction part has the same material as the first sub-electrolyte layer.

23. A gas sensor according to claim 22, characterised in that, At least part of the first junction part is arranged around at least part of the second junction part, and / or at least part of the second junction part is arranged around at least part of the first junction part.

24. A gas sensor according to claim 23, characterised in that, The first junction part comprises a first connecting part and at least two first cross parts, and the first connecting part connects the at least two first cross parts; the second junction part comprises a second connecting part and at least two second cross parts, and the second connecting part connects the at least two second cross parts. Two adjacent first cross parts and the first connecting part are arranged around one second cross part, and two adjacent second cross parts and the second connecting part are arranged around one first cross part.

25. A gas sensor according to claim 24, characterised in that, The first intersection has a first end and a second end, the first end being connected to the first connecting part, and the second end being connected to the second connecting part; The second intersection has a third end and a fourth end, the third end being connected to the second connecting part, and the fourth end being connected to the first connecting part.

26. A gas sensor according to claim 24, characterised in that The first sub-electrolyte layer extends along a first direction, and the first connecting portion and the second connecting portion are disposed opposite each other in a second direction and both extend along the first direction, with the first direction intersecting the second direction; The first intersection and the second intersection are alternately arranged along the first direction and both extend along the second direction.

27. The gas sensor of claim 24, wherein, The first sub-electrolyte layer extends along a first direction, and the first connecting portion and the second connecting portion are disposed opposite to each other in the first direction and both extend along a second direction, with the first direction intersecting the second direction; The first intersection and the second intersection are alternately arranged along the second direction and both extend along the first direction.

28. The gas sensor of claim 23, wherein, The first joint includes a plurality of first sub-joints, and the second joint includes a plurality of second sub-joints, with the plurality of first sub-joints and the plurality of second sub-joints alternately arranged around each other.

29. A gas sensor according to claim 28, characterised in that, The top view of the second sub-junction and / or the first sub-junction along a third direction is a U-shape, where the third direction is the stacking direction of the first sub-electrolyte layer and the first insulating layer.

30. A gas sensor according to any one of claims 22 to 29, characterised in that, Also includes: The first reinforcing layer is located between the first heterogeneous bonding layer and the first sub-electrolyte layer, and the first reinforcing layer and the first sub-electrolyte layer are made of the same material.

31. A gas sensor according to claim 30, characterised in that, The thickness of the first reinforcing layer along a third direction is less than the thickness of the first sub-electrolyte layer in that third direction, where the third direction is the stacking direction of the first sub-electrolyte layer and the first insulating layer.

32. A gas sensor according to claim 31, characterised in that, The thickness of the first reinforcing layer in the third direction is 10 micrometers to 50 micrometers.

33. The gas sensor of claim 22, wherein, The thickness of the first heterogeneous bonding layer along a third direction is less than the thickness of the first sub-electrolyte layer in that third direction, where the third direction is the stacking direction of the first sub-electrolyte layer and the first insulating layer.

34. A gas sensor according to claim 33, characterised in that, The thickness of the first heterogeneous bonding layer in the third direction is 10 micrometers to 50 micrometers.

35. A gas sensor according to claim 33, characterised in that The thickness of the first sub-electrolyte layer in the third direction is 150 micrometers to 300 micrometers.

36. The gas sensor of claim 22, wherein, The material of the first sub-electrolyte layer includes zirconium oxide and additives, the additives including yttrium oxide, cerium oxide or calcium oxide.

37. A gas sensor according to claim 36, characterised in that, In the first sub-electrolyte layer, the content of the additive is 5 mol% to 10 mol%.

38. The gas sensor of claim 22, wherein, The top view area of ​​the first bonding portion along a third direction is 20% to 80% of the top view area of ​​the first heterogeneous bonding layer in that third direction, where the third direction is the stacking direction of the first sub-electrolyte layer and the first insulating layer.

39. The gas sensor of claim 22, wherein, It also includes a second heterogeneous bonding layer, which is located between the second insulating layer and the second sub-electrolyte layer. The second heterogeneous bonding layer includes a third bonding portion and a fourth bonding portion connected in the same layer. The third bonding portion is made of the same material as the second insulating layer, and the fourth bonding portion is made of the same material as the second sub-electrolyte layer.

40. A gas sensor according to claim 39, characterised in that, The heating unit further comprises: A second reinforcing layer is located between the second hetero-junction layer and the second sub-electrolyte layer, and the material of the second reinforcing layer is the same as that of the second sub-electrolyte layer.

41. The gas sensor of claim 1, wherein, Further comprising a heating unit located on the side of the detection unit away from the pump unit, the heating unit comprises a heating electrode, the heating electrode extends along a first direction, and comprises a heating portion, a buffer portion and a lead portion arranged along the first direction, the buffer portion is located between the heating portion and the lead portion, and the total resistance of the buffer portion is less than the total resistance of the heating portion and greater than the total resistance of the lead portion.

42. A gas sensor according to claim 41, characterised in that, The total resistance of the heating portion is 55% to 65% of the total resistance of the heating electrode, the total resistance of the buffer portion is 15% to 30% of the total resistance of the heating electrode, and the total resistance of the lead portion is 15% to 30% of the total resistance of the heating electrode.

43. A gas sensor according to claim 41, characterised in that, The temperature of the heating portion is 400℃ to 800℃, the temperature of the buffer portion is 200℃ to 800℃, and the temperature of the lead portion is less than 200℃.

44. The gas sensor of claim 41, wherein, The lead portion comprises a first sub-lead portion and a second sub-lead portion oppositely arranged in a second direction, and the second direction is perpendicular to the first direction. The buffer portion comprises a first sub-buffer portion connected to the first sub-lead portion and a second sub-buffer portion connected to the second sub-lead portion. The heating portion comprises a first end connected to the first sub-buffer portion and a second end connected to the second sub-buffer portion. The size of the first sub-buffer portion along the second direction gradually increases from the first end to the first sub-lead portion, and the size of the second sub-buffer portion along the second direction gradually increases from the second end to the second sub-lead portion.

45. A gas sensor according to claim 44, characterised in that, The minimum size of the first sub-buffer portion along the second direction is greater than or equal to the size of the first end along the second direction. The maximum size of the first sub-buffer portion along the second direction is less than or equal to the size of the first sub-lead portion along the second direction.

46. A gas sensor according to claim 44, characterised in that The heating electrode further comprises a transition portion, the transition portion comprises a first sub-transition portion connected between the first sub-buffer portion and the first sub-lead portion, and a second sub-transition portion connected between the second sub-buffer portion and the second sub-lead portion. The size of the first sub-transition portion along the second direction gradually increases from the first sub-buffer portion to the first sub-lead portion, and the size of the second sub-transition portion along the second direction gradually increases from the second sub-buffer portion to the second sub-lead portion.

47. The gas sensor of claim 41, wherein, The size of the lead portion along the first direction is greater than the size of the heating portion along the first direction, and the size of the lead portion along the first direction is greater than the size of the buffer portion along the first direction.

48. A gas sensor according to claim 47, characterised in that, The resistivity of the buffer portion is greater than the resistivity of the lead portion.

49. A gas sensor according to claim 47, characterised in that, The heating portion further comprises a plurality of sub-heating portions arranged along the first direction, and the plurality of sub-heating portions are connected in series. The size of the heating portion along the first direction is greater than or equal to the size of the buffer portion along the first direction.

50. A gas sensor according to claim 49, characterised in that, The resistivity of the buffer portion is less than or equal to the resistivity of the heating portion.

51. A gas sensor according to claim 50, characterised in that, The heating portion has a resistivity of 35 μΩ·cm to 50 μΩ·cm, and the buffer portion has a resistivity of 10 μΩ·cm to 25 μΩ·cm.

52. A gas sensor according to claim 49, characterised in that, The buffer portion has a dimension in the first direction that is 50% to 100% of a dimension of the heating portion in the first direction.

53. The gas sensor of claim 44, wherein, The heating electrode has an axis of symmetry extending in the first direction, and the first sub-buffer portion and the second sub-buffer portion are symmetrical about the axis of symmetry. The first sub-buffer portion has a first outer side that is distal from the second sub-buffer portion, the heating portion has a second outer side that is connected to the first outer side, and the first outer side and the second outer side extend in the first direction, or the first outer side is located on a side of the second outer side that is proximal to the second sub-buffer portion.

54. A gas sensor according to claim 53, characterised in that, The first sub-buffer portion has an inner side that is proximal to the second sub-buffer portion, the inner side is a flat surface, or the inner side is a stepped surface.

55. A gas monitoring device, characterized by A gas sensor including any one of claims 1 to 54.

56. A vehicle characterized by A gas monitoring device including claim 55.

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