CN114965648B

CN114965648B - Oxygen sensor

Info

Publication number: CN114965648B
Application number: CN202210559403.4A
Authority: CN
Inventors: 王少熙; 江一智
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2022-05-23
Filing date: 2022-05-23
Publication date: 2023-06-30
Anticipated expiration: 2042-05-23
Also published as: CN114965648A

Abstract

An oxygen sensor is disclosed. The oxygen sensor includes a main body, a separator, an electrode assembly, a separator plate, a cathode current collector, and an anode current collector. The main body comprises a base and a cover body, an air inlet hole communicated with the reaction chamber is formed in the cover body, an air outlet hole communicated with the reaction chamber is formed in the base, and oxygen permeable films are arranged at the air inlet hole and the air outlet hole; the separation membrane separates the reaction chamber into an upper chamber and a lower chamber, and KAc solution is filled in the lower chamber; the electrode assembly includes a cathode member and an anode member; the separator is arranged in the lower chamber to separate the cathode piece from the anode piece; the cathode current collector is fixedly arranged in the lower chamber and positioned at one side of the separator close to the cathode piece; the anode current collector is arranged in the lower chamber and positioned on one side of the separator close to the anode piece, and is fixedly connected with the anode piece. The application can solve the problem of short service life of the oxygen sensor in the prior art.

Description

Oxygen sensor

Technical Field

The application relates to the technical field of sensors, in particular to an oxygen sensor.

Background

Electrochemical oxygen sensors are mainly used for measuring the oxygen content in ambient air. Based on the advantages of simple structure, convenient operation and the like, the chemical oxygen sensor is widely applied to the fields of energy, biology, chemical industry, medical treatment, laboratory and military.

However, the conventional electrochemical sensor has problems such as volatilization and leakage of electrolyte solution, consumption of anode, easy falling-off of internal current collector, poor contact, etc., and the existence of the problems easily causes the electrochemical sensor to not reach the expected service life.

Disclosure of Invention

The main object of the present application is to provide an oxygen sensor, so as to solve the problem of short service life of the oxygen sensor in the prior art.

According to one aspect of embodiments of the present application, there is provided an oxygen sensor comprising:

the main body comprises a base and a cover body, wherein the cover body is arranged on the base and surrounds the base to form a reaction chamber, an air inlet hole communicated with the reaction chamber is formed in the cover body, an air outlet hole communicated with the reaction chamber is formed in the base, and oxygen permeable membranes are arranged at the air inlet hole and the air outlet hole;

the isolation film is arranged in the reaction chamber and divides the reaction chamber into an upper chamber and a lower chamber, and KAc solution is filled in the lower chamber;

an electrode assembly including a cathode member disposed in the upper chamber and an anode member disposed in the lower chamber;

a separator provided to the lower chamber to separate the cathode member from the anode member;

the cathode current collector is fixedly arranged in the lower-layer cavity and positioned at one side of the separator close to the cathode piece; and

the anode current collector is arranged in the lower chamber and is positioned on one side of the separator close to the anode piece, and the anode current collector is fixedly connected with the anode piece.

Further, the anode member includes an anode mesh frame.

Further, the oxygen sensor further includes:

the first contact pin penetrates through the base and is sealed through a first sealing element, and the first contact pin is electrically connected with the anode current collector; and

and the second contact pin penetrates through the base and is sealed through a second sealing element, and the first contact pin is electrically connected with the cathode current collector.

Further, an outer net cover is arranged on the cover body, and the outer net cover is arranged at one end of the air inlet hole, which is away from the base.

Further, a wet film is arranged between the outer net cover and the air inlet end of the air inlet hole.

Further, a diffusion membrane is arranged between the oxygen permeable membrane and one end of the air inlet close to the reaction chamber.

Further, the air inlet hole is positioned at the center of the cover body and is arranged in a staggered manner with the air outlet hole.

Further, the aperture of the air inlet hole and the aperture of the air outlet hole are not more than 50um.

Further, the oxygen permeable membrane and the diffusion membrane are polydimethylsiloxane membrane or polytetrafluoroethylene membrane with a thickness of micron order.

Further, the cathode piece is a metal platinum film plated on the oxygen permeable film in a magnetron sputtering or electroplating mode; and/or the number of the groups of groups,

the anode part is prepared from lead; and/or the number of the groups of groups,

the cathode current collector and the anode current collector are copper or nickel; and/or the number of the groups of groups,

the isolation plate is a polypropylene isolation plate; and/or the number of the groups of groups,

the isolating film is cellophane.

Compared with the prior art, the technical scheme of the application has at least the following technical effects:

in the present application, the electrolyte solution is KAc solution, i.e. potassium acetate solution, which is not easily volatilized, and which is not easily mixed with CO in air, compared with the conventional KOH electrolyte solution ₂ The phenomenon that the electrochemical reaction is further hindered by the generation of a compact lead carbonate or basic lead carbonate layer on the anode part due to the continuous increase of the concentration of carbonate is not easy to occur, namely, the electrolyte solution is KAc solution, so that the service life of the oxygen sensor can be prolonged to a certain extent. In addition, prevent inner circuit loop through setting up division board and barrier film in this application, can improve oxygen sensor's stability in use. Meanwhile, the cathode current collector is fixedly connected to the base, and the anode current collector is fixed to the anode piece, so that the cathode current collector and the anode current collector can be prevented from falling off in advance, and the service life of the oxygen sensor can be further prolonged.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application. In the drawings:

FIG. 1 is a front view of an oxygen sensor of the present application;

fig. 2 is a top view of an oxygen sensor of the present application.

Wherein the above figures include the following reference numerals:

10. a main body; 11. a base; 111. an air outlet hole; 12. a cover body; 121. an air inlet hole; 101. a reaction chamber; 1011. an upper chamber; 1012. a lower chamber; 20. an oxygen permeable membrane; 30. a separation film; 40. KAc solution; 51. a cathode member; 52. an anode member; 60. a partition plate; 70. a cathode current collector; 80. an anode current collector; 90. a first pin; 110. a second pin; 120. a first sealing element; 130. a second sealing element; 140. an outer mesh enclosure; 150. wet film; 160. a diffusion film; 170. and a buffer member.

Detailed Description

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application unless it is specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the authorization specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

Referring to fig. 1 to 2, according to an embodiment of the present application, there is provided an oxygen sensor including a body 10, a separator 30, an electrode assembly, a separator 60, a cathode current collector 70, and an anode current collector 80.

The main body 10 comprises a base 11 and a cover body 12, wherein the cover body 12 is arranged on the base 11 and surrounds the base 11 to form a reaction chamber 101, an air inlet hole 121 communicated with the reaction chamber 101 is formed in the cover body 12, an air outlet hole 111 communicated with the reaction chamber 101 is formed in the base 11, and an oxygen permeable membrane 20 is arranged at each of the air inlet hole 121 and the air outlet hole 111; the isolation film 30 is disposed in the reaction chamber 101 and divides the reaction chamber 101 into an upper chamber 1011 and a lower chamber 1012, and the lower chamber 1012 is filled with the KAc solution 40; the electrode assembly includes a cathode member 51 and an anode member 52, the cathode member 51 being disposed in the upper chamber 1011 and the anode member 52 being disposed in the lower chamber 1012; the separator 60 is disposed in the lower chamber 1012 to separate the cathode member 51 from the anode member 52; the cathode current collector 70 is fixedly disposed in the lower chamber 1012 by fixing pins or the like and positioned at one side of the separator 60 near the cathode member 51; the anode current collector 80 is disposed in the lower chamber 1012 at a side of the separator 60 adjacent to the anode member 52, and the anode current collector 80 is fixedly connected to the anode member 52.

In actual operation, oxygen may enter from the inlet hole 121, pass through the oxygen permeable membrane 20, enter the reaction chamber 101, and after treatment of the KAc solution 40, the electrode assembly, the cathode current collector 70, the anode current collector 80, etc. in the reaction chamber 101, the oxygen content in the environment may be detected.

In the present application, the electrolyte solution is KAc solution 40, i.e. potassium acetate solution, KAc solution 40 is not easily volatilized, and KAc solution 40 is not easily mixed with CO in air compared with the conventional KOH electrolyte solution ₂ The reaction is not easy to occur, and the dense lead carbonate or basic lead carbonate layer is generated on the anode member 52 to prevent the further progress of the electrochemical reaction, that is, the electrolyte solution is KAc solution 40 in the embodiment, so that the oxygen sensing can be prolonged to a certain extentThe service life of the device. In addition, in the present application, the use stability of the oxygen sensor can be improved by providing the partition plate 60 and the partition film 30 to prevent an internal circuit loop. Meanwhile, the present application can prevent the cathode current collector 70 and the anode current collector 80 from falling off in advance by fixedly connecting the cathode current collector 70 to the base 11 and simultaneously fixing the anode current collector 80 to the anode member 52, and can further improve the service life of the oxygen sensor in the present embodiment.

Specifically, the main body 10 in this embodiment may be disposed in a cylindrical shape, may be disposed in a prismatic shape, and may be disposed in an elliptic cylinder or other irregularly-shaped cylindrical structure. Referring to fig. 1 and 2 of the present application, the drawings in this embodiment show a case where the main body 10 is arranged in a cylindrical shape. In this embodiment, the cover 12 and the base 11 are tightly sealed in terms of size, and during processing, the cover 12 and the base 11 are made of the same material, and can be made of cheaper PBS plastics, so that the cost is low, the cover 12 is not easy to damage, the outer diameter of the cover 12 is the same as that of the base 11, and the cover is welded by using an ultrasonic welding technology, so that the cover is completely sealed, and gas can only enter the reaction chamber 101 from top to bottom through the air inlet hole 121 on the cover 12.

Further, the cover 12 in this embodiment is provided with a buffer member 170, the buffer member 170 is an O-ring, and the buffer member 170 surrounds the air inlet 121.

Further, in this embodiment, the pore diameters of the air inlet hole 121 and the air outlet hole 111 are not greater than 50um, and the oxygen permeable membrane 20 covered on the air inlet hole 121 and the air outlet hole 111 is a polydimethylsiloxane membrane or a polytetrafluoroethylene membrane with a thickness of micrometer. The diffusion film 160 is arranged between the oxygen permeable film 20 and one end of the air inlet hole 121 near the reaction chamber 101, optionally, the diffusion film 160 in the embodiment is also a polydimethylsiloxane film or a polytetrafluoroethylene film with a thickness of micron, and by arranging the diffusion film 160, the gas rate entering the air inlet hole 121 can be controlled, the reaction stability of the oxygen sensor is ensured, robustness is provided for different environments, and step response is prevented from being caused when temperature, humidity and pressure are transient.

Optionally, the air inlet hole 121 in this embodiment is located at the center of the cover 12, that is, the air inlet hole 121 is located directly above the reaction chamber 101, and the air inlet hole 121 and the air outlet hole 111 are arranged in a staggered manner (the central axes of the two are not collinear in the height direction of the oxygen sensor and are arranged in a staggered manner), so that the internal pressure balance of the oxygen sensor can be ensured to a certain extent, and the occurrence of false alarm when the pressure/temperature step change occurs can be prevented.

Further, the oxygen sensor in the present embodiment further includes a first pin 90 and a second pin 110. Wherein, the first contact pin 90 is penetrated through the base 11 and sealed by the first sealing element 120, and the first contact pin 90 is electrically connected with the anode current collector 80; the second pin 110 is penetrated through the base 11 and sealed by the second sealing member 130, and the first pin 90 is electrically connected with the cathode current collector 70. Optionally, the first sealing element 120 and the second sealing element 130 are both a combined structure of a sealing ring and a UV glue. After the first contact pin 90 and the second contact pin 110 are installed and sealed by the sealing ring, the connection position of the first contact pin 90 and the second contact pin 110 can be sealed by UV glue, so that the electrolyte solution, namely the KAc solution 40, is ensured not to leak.

Optionally, an outer mesh enclosure 140 is disposed on the cover 12, and the outer mesh enclosure 140 is covered on one end of the air inlet 121 away from the base 11, and impurities can be primarily filtered by disposing the outer mesh enclosure 140, so as to prevent the air inlet 121 from being blocked.

Optionally, a wet film 150 is disposed between the outer screen cover 140 and the air inlet end of the air inlet hole 121, and by disposing the wet film 150, the electrolyte solution and air can be prevented from performing vapor interaction, so as to ensure that the concentration of the electrolyte solution is unchanged.

That is, the oxygen sensor design of the present application comprehensively avoids most of the possible fault problems, and ensures long life of the sensor while also possessing high performance.

As shown in fig. 1, the buffer member 170, the outer net cover 140, the wet film 150, the air inlet holes 121, the diffusion film 160 and the oxygen permeable film 20 on the cover 12 are sequentially arranged from top to bottom, the cover 12 is a circular cover, and the buffer member 170, the outer net cover 140, the wet film 150, the air inlet holes 121, the diffusion film 160 and the oxygen permeable film 20 are arranged at the center of the circle with the cover 12, so that the gas can enter smoothly. The center of the air outlet hole 111 on the base 11 is deviated from that of the cover 12, and the oxygen permeable membrane 20 covered on the air outlet hole 111 is concentric with the air outlet hole 111, and the air outlet hole 111 can balance the pressure difference between the inside and the outside of the oxygen sensor, so as to prevent false alarm when pressure/temperature step change occurs.

Further, in this embodiment, the cathode member 51 of the electrode assembly is a metal platinum film plated on the oxygen permeable film 20 by magnetron sputtering or electroplating, and the thickness of the cathode member 51 may be, for example, 10nm, so that the surface area of the cathode member 51 may be maximized, the internal reaction of the oxygen sensor may be accelerated, and the response speed may be improved, thereby obtaining good performance. And the cathode member 51 is plated on the surface of the oxygen permeable membrane 20, so that the cathode member is not stressed and is not easy to damage in the process of packaging or normal operation.

In the embodiment of the present invention, the anode member 52 includes an anode mesh frame, the anode member 52 is a metal lead frame, the lead frame is designed to be large in size and fills most of the reaction chamber 101, as can be seen from the total reaction formula inside the oxygen sensor, the electrolyte solution of the oxygen sensor is not consumed, and only the anode member 52 reacts with oxygen in the detection gas, so that the large-size design ensures the service life of the oxygen sensor, and reduces the dead space of the reaction chamber at the same time, thereby improving the response rate of the sensor.

In the embodiment of the present invention, the electrolyte solution is KAc solution 40, which is different from the volatile nature of the acidic electrolyte solution, while the OH "in the conventional alkaline electrolyte solution KOH solution reacts with CO2 in the air, resulting in an increasing concentration of carbonate, so that the lead layer on the surface of the anode member 52 combines with the carbonate to form a dense lead carbonate or basic lead carbonate layer, which covers the anode surface and prevents the electrochemical reaction from proceeding further. KAc solution 40 ensures its volatility to some extent without affecting the sensor's internal reactions and lifetime.

In an embodiment of the present invention, the cathode current collector 70 and the anode current collector 80 are copper or nickel or one of copper, and the separator 60 is a polypropylene separator; the separator 30 is cellophane.

In the embodiment of the present invention, when the oxygen sensor is in normal operation, the gas enters the reaction chamber 101 from the cover 12 through the outer mesh cover 140, the wet film 150, the air inlet holes 121, the diffusion film 160 and the oxygen permeable film 20 from top to bottom. The outer mesh enclosure 140 can primarily remove impurity dust in the detection environment, the wet film 150 removes water vapor in the detection gas and prevents the electrolyte solution in the oxygen sensor from volatilizing, after passing through the air inlet 121, the gas uniformly and uniformly passes through the oxygen permeable film 20 by the diffusion film 160, reaches the cathode part 51, and undergoes a reduction reaction with water in the nearby electrolyte solution under the catalytic action of cathode platinum: o (O) ₂ +2H ₂ O+4e-＝4OH ^- At the same time, the anode member 52 is oxidized with the hydroxyl groups in the electrolyte solution: 2pb+4oh- =2pbo+2h ₂ O+4e ^- At this time, electron transfer occurs between the cathode and the anode, and the cathode current collector 70 and the anode current collector 80 are connected to the first pin 90 and the second pin 110 at the bottom of the base 11, respectively. The general reaction formula is: 2Pb+O ₂ ＝2PbO。

From the description of the above embodiments, it is known that gas automatically enters the gas inlet and reacts inside the oxygen sensor, so that a specific usage method of the oxygen sensor with long service life and high performance is as follows: the invention is placed in an experimental environment for initial data test, the theoretical data in the corresponding oxygen concentration can be obtained through detecting the current at two sides of the first pin and the second pin or connecting the two sides of the first pin and the second pin to the amplifying and collecting circuit, and then the invention is placed in the tested environment, and the oxygen concentration of the tested environment can be detected through detecting the data obtained at two sides of the first pin and the second pin.

Spatially relative terms, such as "above … …," "above … …," "upper surface at … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations of "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, the terms "first", "second", etc. are used to define the components, and are merely for convenience of distinguishing the corresponding components, and unless otherwise stated, the terms have no special meaning, and thus should not be construed as limiting the scope of the present application.

The foregoing is merely a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and variations may be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An oxygen sensor, comprising:

the device comprises a main body (10), wherein the main body (10) comprises a base (11) and a cover body (12), the cover body (12) is arranged on the base (11) and surrounds the base (11) to form a reaction chamber (101), an air inlet hole (121) communicated with the reaction chamber (101) is formed in the cover body (12), an air outlet hole (111) communicated with the reaction chamber (101) is formed in the base (11), and an oxygen permeable membrane (20) is arranged at each of the air inlet hole (121) and the air outlet hole (111);

the separation film (30), the separation film (30) is arranged in the reaction chamber (101) and divides the reaction chamber (101) into an upper chamber (1011) and a lower chamber (1012), and KAc solution (40) is filled in the lower chamber (1012);

an electrode assembly (50), the electrode assembly (50) comprising a cathode member (51) and an anode member (52), the cathode member (51) being disposed in the upper chamber (1011), the anode member (52) being disposed in the lower chamber (1012);

a separator (60), the separator (60) being provided to the lower chamber (1012) to separate the cathode member (51) from the anode member (52);

a cathode current collector (70), wherein the cathode current collector (70) is fixedly arranged in the lower layer chamber (1012) and is positioned at one side of the separator (60) close to the cathode piece (51); and

an anode current collector (80), wherein the anode current collector (80) is arranged in the lower chamber (1012) and is positioned on one side of the separation plate (60) close to the anode piece (52), and the anode current collector (80) is fixedly connected to the anode piece (52).

2. The oxygen sensor of claim 1, wherein the anode member (52) comprises an anode mesh frame.

3. The oxygen sensor of claim 1, further comprising:

a first pin (90), the first pin (90) penetrating the base (11) and sealed by a first sealing element (120), the first pin (90) being electrically connected to the anode current collector (80); and

and a second contact pin (110), wherein the second contact pin (110) penetrates through the base (11) and is sealed by a second sealing element (130), and the first contact pin (90) is electrically connected with the cathode current collector (70).

4. The oxygen sensor according to claim 1, wherein an outer net cover (140) is arranged on the cover body (12), and the outer net cover (140) is covered at one end of the air inlet hole (121) away from the base (11).

5. The oxygen sensor of claim 4, wherein a wet film (150) is provided between the outer screen (140) and the inlet end of the inlet aperture (121).

6. The oxygen sensor according to claim 1, characterized in that a diffusion membrane (160) is arranged between the oxygen permeable membrane (20) and the end of the gas inlet aperture (121) close to the reaction chamber (101).

7. The oxygen sensor according to claim 1, wherein the air inlet hole (121) is located at the center of the cover body (12) and is offset from the air outlet hole (111).

8. The oxygen sensor of claim 1, wherein the aperture of both the inlet aperture (121) and the outlet aperture (111) is no greater than 50um.

9. The oxygen sensor of claim 6, wherein the oxygen permeable membrane (20) and the diffusion membrane (160) are polydimethylsiloxane or polytetrafluoroethylene films with a thickness of a micrometer scale.

10. Oxygen sensor according to any one of claims 1 to 9, characterized in that the cathode element (51) is a metallic platinum film plated on the oxygen permeable film (20) by means of magnetron sputtering or electroplating; and/or the number of the groups of groups,

the anode part (52) is prepared from lead; and/or the number of the groups of groups,

the cathode current collector (70) and the anode current collector (80) are copper or nickel; and/or the number of the groups of groups,

the isolation plate (60) is a polypropylene isolation plate; and/or the number of the groups of groups,

the isolating film (30) is cellophane.