KR20210020472A - Electrochemical sensor and manufacturing method thereof - Google Patents

Abstract

The present invention provides an electrochemical sensor, which comprises: a relative electrode where a charge can be moved in the electrochemical sensor; a first solid electrolyte and a second solid electrolyte arranged in parallel to each other on the same layer on the relative electrode; a first work electrode formed to come in contact with both of an upper surface of the first solid electrolyte and an upper surface of the second solid electrolyte; and a second work electrode distinguished from the first work electrode and formed to come in contact with the upper surface of the first solid electrolyte and the upper surface of the second solid electrolyte.

Description

Electrochemical sensor and manufacturing method thereof TECHNICAL FIELD

Embodiments of the present invention relate to an electrochemical sensor and a method of manufacturing the same, and more particularly, to an electrochemical sensor capable of selectively detecting various types of gases using a plurality of solid electrolytes.

The gas sensor is a device that detects the concentration or presence of a specific type of gas, and may detect a specific chemical substance contained in the gas, convert the concentration into an electrical signal, and output it. For example, gas sensors are used to detect harmful gases such as _{CO 2} , NO, NO _x , and SO _{2 for protection of life safety.}

The gas sensor may include, for example, an electrochemical sensor using an electrochemical reaction. The electrochemical sensor has a small size, small power required for driving, and can have excellent linearity and repeatability. In addition, there are advantages of superior selectivity, simple operation principle, and short measurement time than other gas sensors such as semiconductor type or dielectric type.

The electrochemical sensor can detect the concentration of the gas by, for example, measuring the amount of electrons (ie, current) generated when the detection target gas undergoes an oxidation or reduction reaction by the action of an electrode. In the electrochemical sensor, for example, a solid electrolyte having ionic conductivity between electrodes can be used.

Such an electrochemical gas sensor has a problem that is inevitably limited in the selectivity of a detection target gas depending on the type of electrolyte or the potential difference between electrodes.

The present invention has been devised to improve the above problems, and an object of the present invention is to provide an electrochemical sensor that maximizes selectivity of a detection gas by using a plurality of solid electrolytes and a plurality of working electrodes. However, these problems are exemplary, and the scope of the present invention is not limited thereby.

An electrochemical sensor according to an embodiment of the present invention includes a counter electrode through which electric charges can move in the electrochemical sensor; A first solid electrolyte and a second solid electrolyte disposed side by side in the same layer on the counter electrode; A first working electrode formed to contact both an upper surface of the first solid electrolyte and an upper surface of the second solid electrolyte; And a second working electrode formed to contact both the upper surface of the first solid electrolyte and the upper surface of the second solid electrolyte and separated from the first working electrode.

According to an embodiment, the electrochemical sensor includes: a first charge current collector formed on the first working electrode; And a second charge current collector formed on the second working electrode.

According to an embodiment, the first charge current collector is electrically connected to the counter electrode through an external first circuit, and the second charge current collector is through an external second circuit different from the first circuit. It may be electrically connected to the counter electrode.

According to an embodiment, a first potential difference applied between the first working electrode and the counter electrode and a second potential difference applied between the second working electrode and the counter electrode may be different from each other.

According to an embodiment, an oxidation reaction of a plurality of gases including a first gas and a second gas may occur in the first working electrode and the second working electrode, and the first potential difference is the oxidation of the first gas. A potential difference at which a reaction is promoted, and the second potential difference may be a potential difference at which an oxidation reaction of the second gas is accelerated.

According to an embodiment, a first current value measured between the first working electrode and the counter electrode by the first potential difference and a second electric current value measured between the second working electrode and the counter electrode according to the second potential difference Based on the current value, a plurality of types of gases can be detected.

According to an embodiment, the first current value due to the oxidation reaction of the first gas and the second current value due to the oxidation reaction of the first gas are different, and the first current value and the second current value are By using it, the type of the first gas can be determined.

According to an embodiment, the first solid electrolyte may have oxide ion conductivity, and the second solid electrolyte may have hydrogen ion conductivity.

According to an embodiment, the first solid electrolyte may supply oxide ions generated by electrolysis of water at the counter electrode to the working electrode, thereby promoting an oxidation reaction of the gas at the working electrode.

According to an embodiment, the second solid electrolyte may promote the oxidation reaction at the working electrode by moving hydrogen ions generated by an oxidation reaction of gas at the working electrode to the counter electrode.

A method of manufacturing an electrochemical sensor according to an embodiment of the present invention includes forming a counter electrode in the form of a metal network; Forming a first solid electrolyte and a second solid electrolyte side by side in the same layer on the counter electrode; Forming a first working electrode to contact both an upper surface of the first solid electrolyte and an upper surface of the second solid electrolyte; And forming a second working electrode separated from the first working electrode so as to contact both the upper surface of the first solid electrolyte and the upper surface of the second solid electrolyte.

According to an embodiment, a method of manufacturing the electrochemical sensor may include forming a first charge current collector on the first working electrode; And forming a second charge current collector on the second working electrode.

According to an embodiment, the first solid electrolyte may include a material having oxide ion conductivity, and the second solid electrolyte may include a material having hydrogen ion conductivity.

According to an embodiment, as the second solid electrolyte, a material doped with barium may be used.

According to an embodiment, the second solid electrolyte may include barium zirconate-cerate, which is simultaneously doped with yttrium (Y) and ytterbium (Yb) ions.

The gas detection method of an electrochemical sensor according to an embodiment of the present invention includes a counter electrode, a first solid electrolyte and a second solid electrolyte arranged side by side on an upper surface of the counter electrode, and Measuring a first current value between the first working electrode and the counter electrode by using an electrochemical sensor including a first working electrode and a second working electrode formed to all contact the upper surface of the solid electrolyte; Measuring a second current value between the second working electrode and the counter electrode; And determining the type of gas in which an oxidation reaction occurs in the first working electrode and the second working electrode by using the first current value and the second current value.

According to an embodiment, in the gas detection method of the electrochemical sensor, a first potential difference is applied between the first working electrode and the counter electrode, and different from the first potential difference between the second working electrode and the counter electrode. The step of applying a second potential difference; may further include.

According to an embodiment, the first working electrode and the second working electrode promote an oxidation reaction of a plurality of gases including a first gas and a second gas, and the first potential difference is the oxidation of the first gas. A potential difference at which a reaction is promoted, and the second potential difference may be a potential difference at which an oxidation reaction of the second gas is accelerated.

Other aspects, features, and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

According to an embodiment of the present invention made as described above, a plurality of solid electrolytes and a plurality of working electrodes are used to maximize selectivity of the detection gas.

In particular, according to an embodiment of the present invention, it is possible to maximize the selectivity of detection of the hydrocarbon gas by promoting the oxidation reaction of the hydrocarbon gas.

Of course, the scope of the present invention is not limited by these effects.

1 is a perspective view schematically showing an electrochemical sensor 100 according to an embodiment of the present invention.
2 is a schematic front view of the electrochemical sensor 100 shown in FIG. 1.
3A to 3D are perspective views schematically showing a method of manufacturing an electrochemical sensor 100 according to an embodiment of the present invention.
4 is a schematic flowchart of a method of manufacturing an electrochemical sensor 100 according to an embodiment of the present invention.

Since the present invention can apply various transformations and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. Effects and features of the present invention, and a method of achieving them will be apparent with reference to the embodiments described later in detail together with the drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various forms.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and when describing with reference to the drawings, the same or corresponding constituent elements are assigned the same reference numerals, and redundant descriptions thereof will be omitted. .

In the following embodiments, terms such as first and second are used for the purpose of distinguishing one constituent element from other constituent elements rather than a limiting meaning.

In the following examples, the singular expression includes the plural expression unless the context clearly indicates otherwise.

In the following embodiments, terms such as include or have means that the features or elements described in the specification are present, and do not preclude the possibility of adding one or more other features or elements in advance.

In the following embodiments, when a part such as a region, component, part, block, module, etc. is above or on another part, not only the case directly above the other part, but also another region, component, part in the middle thereof. , Blocks, modules, etc. are also included.

In the drawings, components may be exaggerated or reduced in size for convenience of description. For example, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, and the present invention is not necessarily limited to what is shown.

In the following embodiments, when a region, component, unit, block, module, etc. are connected, not only the case where the region, component, unit, block, module are directly connected, but also the region, component, unit, block, module, etc. Other areas, components, parts, blocks, and modules are interposed between them and indirectly connected.

1 is a perspective view schematically showing an electrochemical sensor 100 according to an embodiment of the present invention. 2 is a schematic front view of the electrochemical sensor 100 shown in FIG. 1.

1 and 2, an electrochemical sensor 100 according to an embodiment of the present invention includes a counter electrode 10, a first solid electrolyte 21, A second solid electrolyte 22, a working electrode 30, and a charge collector 40 may be included.

In the electrochemical sensor 100, solid electrolytes 21 and 22 may be disposed between the working electrode 30 and the counter electrode 10. According to an embodiment, the solid electrolytes 21 and 22 may be positioned on the counter electrode 10, and the working electrode 30 may be positioned on the solid electrolytes 21 and 22. A charge collector 40 may be positioned on the working electrode 30, and the charge collector 40 may be connected to the counter electrode 10 through an external circuit 50.

The counter electrode 10, the solid electrolytes 21 and 22, the working electrode 30, and the charge collector 40 may be electrically connected to each other.

In the working electrode 30, an electrochemical reaction (eg, redox reaction) of the gas to be detected may occur. Therefore, the working electrode 30 may be referred to as a sensing electrode. ^{For example, electrons e-} may be generated by an oxidation reaction of the gas to be detected in the working electrode 30. The working electrode a charge collector (40) coupled to the (30), electronic (e ^-), generated by the oxidation reaction to via (collect) the external circuit (50) collect and to flow as a counter electrode (10) I can.

Meanwhile, the electrochemical sensor 100 may be installed so that the counter electrode 10 contacts the water surface WL. For example, in an environment in which gas detection is required, a water supply port, a drain port, a water channel, a water channel, etc. may pass under the electrochemical sensor 100. Accordingly, the lower surface of the electrochemical sensor 100, that is, the lower portion of the counter electrode 10 may contact the water surface WL. In the counter electrode 10, a reaction such as water electrolysis or water synthesis may occur. The counter electrode 10 may be referred to as a water electrode.

According to an embodiment of the present invention, the circuit 50 may apply a potential difference V between the working electrode 30 and the counter electrode 10. Alternatively, the circuit 50 may apply a potential difference V between the upper and lower surfaces of the solid electrolytes 21 and 22.

The solid electrolytes 21 and 22 may have ion mobility or ion conductivity according to the potential difference (V). Accordingly, ions generated by the redox reaction of the gas to be detected in the working electrode 30 may flow through the solid electrolytes 21 and 22. For example, by the redox reaction in the working electrode 30, oxide ions (O ^2- ) and/or hydrogen ions (H ⁺ ) may flow through the solid electrolytes 21 and 22.

As described above, by means of electrons (e-), oxide ions (O ^2- ), hydrogen ions (H ⁺ ), etc. generated by the redox reaction of the gas to be detected in the working electrode 30, the electrochemical sensor ( 100) may flow. By measuring this current value, the electrochemical sensor 100 can detect gas.

According to an embodiment, when an oxidation reaction of a hydrocarbon gas (eg, pentane, C ₅ H ₁₂ ) occurs in the working electrode 30, oxide ions (O ^2- ) may be consumed as a reactant, and a product As electrons (e-) or hydrogen ions (H ⁺ ) may be generated. At this time, for example, when a potential difference (V) is applied to the counter electrode 10 so that the potential of the working electrode 30 is high, the current is relative to the working electrode 30 through the layers of the solid electrolytes 21 and 22. It may flow in a direction flowing to the electrode 10. In addition, electrons (e-) generated in the working electrode 30 are collected by the charge collector 40 coupled to the working electrode 30, and the counter electrode ( 10) can flow. Therefore, for example, the working electrode 30 may be an anode, and the counter electrode 10 may be a cathode.

As described above, the detection target gas can be detected by measuring a current value by movement of ^{oxide ions (O 2-} ) and hydrogen ions (H ^{+ ).} The current value may vary depending on, for example, a supply potential difference (V). The current value may not be proportional to the potential difference (V), for example, even if the potential difference (V) is not supplied (ie, even if V = 0), the current may flow due to the redox reaction of the detection target gas. .

According to an embodiment of the present invention, the value (or range) of the potential difference V at which the oxidation reaction is accelerated may be different depending on the type of gas. According to an embodiment, the ionic mobility (or ionic conductivity) of the solid electrolytes 21 and 22 has different values depending on the potential difference V, and this value may be provided through an experiment or the like in advance. Therefore, the relationship between the type of gas, the potential difference (V), and the corresponding current value may be provided through an experiment in advance.

Accordingly, according to an embodiment of the present invention, a specific type of gas can be detected by checking a current value measured by supplying a specific potential difference (V) or a pattern of a current value measured according to the potential difference (V).

According to an embodiment of the present invention, a plurality of solid electrolytes including the first solid electrolyte 21 and the second solid electrolyte 22 may be disposed in parallel between the working electrode 30 and the counter electrode 10. have.

According to an embodiment, the first solid electrolyte 21 and the second solid electrolyte 22 are disposed side by side on the same plane or on the same layer, and the first solid electrolyte 21 and the second solid electrolyte 22 One side (eg, the upper surface) of the first solid electrolyte (21) and the other side (eg, the lower surface) of the first solid electrolyte (21) and the second solid electrolyte (22) contact the counter electrode (10). I can. For example, a part of the lower surface of the working electrode 30 may be in contact with the upper surface of the first solid electrolyte 21, and the remaining part of the lower surface of the working electrode 30 may be in contact with the upper surface of the second solid electrolyte 22. have. In addition, a part of the upper surface of the counter electrode 10 may be in contact with the lower surface of the first solid electrolyte 21, and the remaining part of the upper surface of the counter electrode 10 may be in contact with the lower surface of the second solid electrolyte 22.

Accordingly, the working electrode 30 and the counter electrode 10 may be electrically connected to each other through a first path through the first solid electrolyte 21 and a second path through the second solid electrolyte 22. In other words, the working electrode 30 and the counter electrode 10 are electrically connected through the first solid electrolyte 21, and the working electrode 30 and the counter electrode 10 are connected through the second solid electrolyte 22. Can be electrically connected.

The first solid electrolyte 21 and the second solid electrolyte 22 may be formed of different materials. For example, the first solid electrolyte 21 may ^{include a material having oxide ions (O 2-} ) conductivity, and the second solid electrolyte 22 may have hydrogen ions (H ⁺ ) conductivity. It may contain substances. That is, the first solid electrolyte 21 may ^{move oxide ions (O 2-} ), and the second solid electrolyte 22 may ^{move hydrogen ions (H +} ).

According to an embodiment of the present invention, the first solid electrolyte 21 ^{works by supplying oxide ions (O 2 -} ) generated by electrolysis of water in the counter electrode 10 to the working electrode 30, The oxidation reaction of the gas to be detected in the electrode 30 can be accelerated. ^{In addition, the second solid electrolyte 22 moves hydrogen ions (H +} ) generated by the oxidation reaction of the gas to be detected in the working electrode 30 to the counter electrode 10, so that the working electrode 30 It can accelerate the oxidation reaction of. Therefore, the electrochemical sensor 100 according to an exemplary embodiment of the present invention uses a plurality of electrolytes including the first solid electrolyte 21 and the second solid electrolyte 22, so that the selectivity of the gas to be detected is Can improve.

Hereinafter, when the electrochemical sensor 100 detects pentane (C ₅ H ₁₂ ), the first path through the first solid electrolyte 21 and the second path through the second solid electrolyte 22 For, an example of a chemical reaction equation will be described.

First, with respect to the first path through the first solid electrolyte 21, electrolysis of water as follows may occur in the counter electrode 10.

^{_{H 2 O + 2e - → H}} 2 + O 2-

^{Oxide ions (O2-} ) generated in the counter electrode 10 are supplied to the working electrode 30 through the first solid electrolyte 21, and oxidative dehydrogenation of pentane in the working electrode 30 as follows ( oxidative dehydrogenation) reaction.

^{_{C 5 H 12 + O 2- →}} C 5 H 10 + H 2 O + 2e -

^{Electrons e-} generated in the working electrode 30 are collected by the charge collector 40 and may flow to the counter electrode 10 through the external circuit 50.

Next, with respect to the second path through the second solid electrolyte 22, the following oxidative dehydrogenation reaction of pentane may occur in the working electrode 30.

_{C 5 H 12 → C 5 H} 10 + 2H + + 2e -

^{Electrons e-} generated in the working electrode 30 are collected by the charge collector 40 and may flow to the counter electrode 10 through the external circuit 50. Hydrogen ions (H ⁺ ) generated in the working electrode 30 are supplied to the counter electrode 10 through the second solid electrolyte 22 to accelerate the oxidative dehydrogenation reaction of the pentane in the working electrode 30. I can. Hydrogen ions (H+) supplied to the counter electrode 10 may be used as a reactant for the synthesis of water in the counter electrode 10 as follows.

^{2H + + 2e - + 1/2 O} 2- → H 2 O

Therefore, according to an embodiment of the present invention, using a plurality of solid electrolytes including the first solid electrolyte 21 and the second solid electrolyte 22 between the working electrode 30 and the counter electrode 10, The redox reaction in the electrode 30 can be promoted, and there is an effect of maximizing the selectivity of the gas to be detected.

Meanwhile, the oxidation ion conductivity (or mobility) of the first solid electrolyte 21 as described above may vary depending on the potential difference V between the upper and lower surfaces of the first solid electrolyte 21, and the second solid electrolyte The hydrogen ion conductivity of 22 may also vary depending on the potential difference V between the upper and lower surfaces of the second solid electrolyte 22. Oxide ion conductivity and hydrogen ion conductivity according to the potential difference (V) may be measured in advance through an experiment. As the oxide ion conductivity and hydrogen ion conductivity are higher, the gas oxidation reaction in the working electrode 30 may be promoted. According to various embodiments of the present disclosure, the value (or range) of the potential difference V at which the oxidation reaction is accelerated may be different for each type of gas. The potential difference (V) for accelerating the oxidation reaction for each gas type (for example, increasing the current value) can be known through measurement in advance.

Meanwhile, the present invention is not limited to the above-described examples, and in addition to the first solid electrolyte 21 and the second solid electrolyte 22, in order to improve the selectivity of the detection target gas, the redox reaction in the working electrode 30 is performed. Other solid electrolytes that can be promoted may be further included. For example, a plurality of solid electrolytes of three or more types are arranged in parallel between the working electrode 30 and the counter electrode 10 to improve the mobility of ^{oxide ions (O 2-} ) and hydrogen ions (H ^{+ ).} I will be able to make it. For example, the plurality of solid electrolytes are arranged side by side on the same layer (that is, a layer between the working electrode 30 and the counter electrode 10), and one surface of the plurality of solid electrolytes (eg, the upper surface) Silver may contact the working electrode 30, and the other surface (eg, the lower surface) of the plurality of solid electrolytes may contact the counter electrode 10.

The working electrode 30 may be disposed above the first solid electrolyte 21 and the second solid electrolyte 22 so as to contact both the first solid electrolyte 21 and the second solid electrolyte 22. If the electrochemical sensor 100 includes a plurality of solid electrolytes of three or more types, the working electrode 30 may be disposed to contact all of the plurality of solid electrolytes.

In the working electrode 30, an electrochemical reaction (eg, redox reaction) of the detection target gas may occur according to the potential difference V. For example, the working electrode 30 can act as a catalyst, which can accelerate the oxidation reaction of the gas to be detected.

The working electrode 30 may be formed of a plurality of working electrodes including a first working electrode 31 and a second working electrode 32. The plurality of working electrodes may be disposed on the first solid electrolyte 21 and the second solid electrolyte 22 so as to contact both the first solid electrolyte 21 and the second solid electrolyte 22, respectively.

A charge current collector may be coupled to each of the plurality of working electrodes. Referring to FIG. 1, a first charge collector 41 may be attached to an upper portion of the first working electrode 31, and a second charge collector 42 may be attached to an upper portion of the second working electrode 32. Can be.

Different potential differences may be applied to the first working electrode 31 and the second working electrode 32 based on the counter electrode 10. For example, a first potential difference may be applied between the first working electrode 31 and the counter electrode 10, and between the second working electrode 32 and the counter electrode 10, a first potential difference Two potential differences can be applied.

The first potential difference and the second potential difference may be set as potential differences in which oxidation reactions are likely to occur, respectively, according to the types of the plurality of detection target gases. That is, as described above, the value (or range) of the potential difference V at which the oxidation reaction is accelerated may be different for each type of gas. The potential difference (V) for accelerating the oxidation reaction for each gas type (for example, increasing the current value) can be known through measurement in advance.

Thus, for example, a first potential difference is supplied to the first working electrode 31 to promote the oxidation reaction of the first gas, and the second working electrode 32 is provided with an oxidation reaction of a second gas different from the first gas. This accelerated second potential difference can be supplied.

Meanwhile, it goes without saying that the electrochemical sensor 100 according to the embodiment of the present invention may be composed of three or more working electrodes in addition to the first working electrode 31 and the second working electrode 32. The potential difference applied to each of the working electrodes may be set as potential differences for accelerating the oxidation reaction of the plurality of detection target gases.

According to an embodiment of the present invention, a first circuit connecting the first working electrode 31 and the counter electrode 10 and a second circuit connecting the second working electrode 32 and the counter electrode 10 are provided. They can be distinguished from each other. For example, the first circuit and the second circuit may be independent of each other. Accordingly, the current value due to the first potential difference in the first circuit and the current value due to the second potential difference in the second circuit can be measured independently of each other.

As described above, depending on the potential difference, the degree of the oxidation reaction of the specific gas may vary, and thus the measured current value may vary. In addition, for each type of gas, the degree of oxidation (or current value pattern) according to the potential difference may vary. Accordingly, according to an embodiment of the present invention, the type of the detected gas can be identified by using a pattern of current values measured by each of the plurality of working electrodes 31 and 32.

In other words, by using the current value measured according to the first potential difference at the first working electrode 31 and the current value measured according to the second potential difference at the second working electrode 32, the type of gas to be detected can be checked have.

In this way, it is possible to further maximize gas selectivity by using not only the plurality of solid electrolytes 21 and 22 but also the plurality of working electrodes 31 and 32.

3A to 3D are perspective views schematically showing a method of manufacturing an electrochemical sensor 100 according to an embodiment of the present invention.

Referring to FIG. 3A, first, the counter electrode 10 may be formed in the form of a thin metal mesh or a metal foil. The counter electrode 10 may include nickel (Ni) or platinum (Pt).

Referring to FIG. 3B, a thin solid electrolyte 21 and 22 layer may be formed on the metal net or the metal thin film. The layers of the solid electrolytes 21 and 22 may be formed by Doctor Blade technology, and may be formed to a thickness of several tens of micrometers.

The solid electrolytes 21 and 22 may be formed such that the first solid electrolyte 21 and the second solid electrolyte 22, which are different materials, are positioned side by side in the same layer.

The first solid electrolyte 21 may ^{include a material having oxide ion (O 2-} ) conductivity, and the second solid electrolyte 22 may include a material having hydrogen ion (H ⁺ ) conductivity. I can.

According to an embodiment, the first solid electrolyte 21 is at least one of yttrium stabilized zirconia (Yittrium Stabilized Zirconia, YSZ), CeO _{2 doped with gadolinium (Gd), and Bi 2} O ₃ doped with yttrium (Y). It may include. For example, the first solid electrolyte 21 may be made of one material selected from the above materials.

According to an embodiment, in the second solid electrolyte 22, a material doped with barium (Ba), such as _{BZCYYb (described below), BaTbO 3} , BaCeO ₃ ^{, etc., is used to achieve hydrogen ion (H +} ) conductivity. Can be given.

^{BZCYYb having hydrogen ion (H +} ) conductivity according to an embodiment of the present invention is BaZr0.1Ce0.7Y0.1Yb0.1O3-δ, and barium doped simultaneously with yttrium (Y) and ytterbium (Yb) ions It represents a zirconate-cerate (Barium zirconate-cerate). BZCYYb may exhibit higher conductivity than an oxide ion conductive electrolyte such as yttrium stabilized zirconia (YSZ) at lower operating temperatures. The BZCYYb electrolyte can facilitate the transport of both proton and oxide ion vacancy, depending on the operating conditions. BZCYYb powder can be synthesized by the Pecini method.

Referring to FIG. 3C, a working electrode 30 serving as a catalyst for gas oxidation reaction may be formed on the solid electrolytes 21 and 22 layer.

According to an embodiment of the present invention, a plurality of working electrodes including the first working electrode 31 and the second working electrode 32 may be formed on the solid electrolytes 21 and 22 layer. The plurality of working electrodes may be formed by lithography or screen printing.

Each of the plurality of working electrodes may be formed to contact both the first solid electrolyte 21 and the second solid electrolyte 22. That is, a part of the first working electrode 31 may be formed to be disposed on the first solid electrolyte 21 and a part of the second solid electrolyte 22, and a part of the second working electrode 32 may be It may be formed so as to be disposed on the first solid electrolyte 21 and the remaining portion on the second solid electrolyte 22.

The plurality of working electrodes 31 and 32 may be formed of a material that catalyzes an oxidation reaction of a gas.

According to an embodiment, gold (Au) may be used as the material of the working electrodes 31 and 32, and in order to improve the stability of gold, gold is dispersed in a NiO matrix, thereby agglomeration and particles It prevents grain growth and keeps the shape of the original gold particles. For example, gold and NiO powder can be mixed in an organic solvent to obtain a paste. The paste can be deposited on the solid electrolytes 21 and 22 by lithography or screen printing.

_{According to an embodiment, Mg 2} V ₂ O ₇ and/or Mg ₃ V ₂ O ₈ may be used as the material of the working electrodes 31 and 32. The catalysts can provide a suitable amount of oxidizing materials to activate the reaction of alkanes at relatively low temperatures. The catalysts may be prepared by a citrate method using _{Mg(NO 3} ) ₂ 6H ₂ O and NH ₄ VO ₃ as a starting material. The produced result can be lithography or screen printed.

According to an embodiment, palladium (Pd) may be used as a material of the working electrodes 31 and 32. Porous palladium (Pd) can act as a catalyst for the oxidation of hydrocarbons.

In various embodiments of the present invention, a plurality of working electrodes including the first working electrode 31 and the second working electrode 32 may be formed of one selected from the above-described materials.

Referring to FIG. 3D, very thin electrodes are formed on the plurality of working electrodes 31 and 32 to serve as a charge collector 40, respectively. According to an embodiment, the first charge collector 41 may be formed on the first working electrode 31, and the second charge collector 42 may be formed on the second working electrode 32.

The charge collector 40 may include at least one material selected from palladium (Pd), platinum (Pt), and gold (Au).

4 is a schematic flowchart of a method of manufacturing an electrochemical sensor 100 according to an embodiment of the present invention.

Referring to FIG. 4, in S401, the counter electrode 10 may be formed in the form of a metal mesh. The counter electrode 10 may be in the form of a metal mesh and may be manufactured in the form of a thin metal thin film. The counter electrode 10 may include nickel (Ni) or platinum (Pt).

In S402, on the counter electrode 10, the first solid electrolyte 21 and the second solid electrolyte 22 may be formed side by side on the same layer. The layers of the solid electrolytes 21 and 22 may be formed by a Doctor Blade technique, and may be formed to a thickness of several tens of micrometers.

The first solid electrolyte 21 may have oxide ion (O ^2- ) conductivity, and the second solid electrolyte 22 may have hydrogen ion (H ⁺ ) conductivity. The first solid electrolyte 21 may include at least one of Yittrium Stabilized Zirconia (YSZ), CeO _{2 doped with gadolinium (Gd), and Bi 2} O ₃ doped with yttrium (Y). The second solid electrolyte 22 is barium zirconate-cerate, which is simultaneously doped with yttrium (Y) and ytterbium (Yb) ions (BaZr0.1Ce0.7Y0.1Yb0.1O3-δ) , BaTbO ₃ , BaCeO ₃ It may include at least one of.

In S403, the first working electrode 31 and the second working electrode 32 may be formed so as to contact both the upper surface of the first solid electrolyte 21 and the upper surface of the second solid electrolyte 22, for example It may be formed by lithography or screen printing. The first working electrode 31 and the second working electrode 32 may act as a catalyst for an oxidation reaction of a gas.

The first working electrode 31 and the second working electrode 32 are gold (Au) dispersed in a NiO matrix, Mg ₂ V ₂ O ₇ , Mg ₃ V ₂ O ₈ , porous palladium ( It may include at least one of Pd).

In S404, a first charge collector 41 may be formed on the first working electrode 31, and a second charge collector 42 may be formed on the second working electrode 32. The first charge collector 41 and the second charge collector 42 may include at least one material selected from palladium (Pd), platinum (Pt), and gold (Au).

Although the present invention has been described with reference to an embodiment shown in the drawings, this is only exemplary, and those of ordinary skill in the art will understand that various modifications and variations of the embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

100: electrochemical sensor
10: counter electrode
21: first solid electrolyte
22: second solid electrolyte
30: working electrode
31: first working electrode
32: second working electrode
40: electric charge collector
41: first charge current collector
42: second charge current collector
50: circuit

Claims (18)

A counter electrode through which electric charges can move in the electrochemical sensor;
A first solid electrolyte and a second solid electrolyte disposed side by side in the same layer on the counter electrode;
A first working electrode formed to contact both an upper surface of the first solid electrolyte and an upper surface of the second solid electrolyte; And
The electrochemical sensor comprising; a second working electrode formed to contact both the upper surface of the first solid electrolyte and the upper surface of the second solid electrolyte and separated from the first working electrode. The method according to claim 1,
A first charge collector formed on the first working electrode; And
The electrochemical sensor further comprising; a second charge collector formed on the second working electrode. The method according to claim 2,
The first charge current collector is electrically connected to the counter electrode through an external first circuit,
The second charge current collector is electrically connected to the counter electrode through an external second circuit different from the first circuit. The method according to claim 1,
An electrochemical sensor, wherein a first potential difference applied between the first working electrode and the counter electrode and a second potential difference applied between the second working electrode and the counter electrode are different from each other. The method of claim 4,
In the first working electrode and the second working electrode, an oxidation reaction of a plurality of gases including a first gas and a second gas may occur,
The first potential difference is a potential difference at which the oxidation reaction of the first gas is accelerated,
The second potential difference is a potential difference at which an oxidation reaction of the second gas is accelerated, an electrochemical sensor. The method of claim 5,
Based on a first current value measured between the first working electrode and the counter electrode by the first potential difference and a second current value measured between the second working electrode and the counter electrode based on the second potential difference, An electrochemical sensor that detects a plurality of types of gases. The method of claim 6,
The first current value due to the oxidation reaction of the first gas and the second current value due to the oxidation reaction of the first gas are different,
An electrochemical sensor for determining the type of the first gas using the first current value and the second current value. The method according to claim 1,
The first solid electrolyte has oxide ion conductivity,
The second solid electrolyte has a hydrogen ion conductivity, electrochemical sensor. The method of claim 8,
The first solid electrolyte, by supplying oxide ions generated by electrolysis of water at the counter electrode to the working electrode to promote an oxidation reaction of gas at the working electrode. The method of claim 8,
The second solid electrolyte is an electrochemical sensor that promotes the oxidation reaction at the working electrode by moving hydrogen ions generated by an oxidation reaction of a gas at the working electrode to the counter electrode. Forming a counter electrode in the form of a metal mesh;
Forming a first solid electrolyte and a second solid electrolyte side by side in the same layer on the counter electrode;
Forming a first working electrode to contact both an upper surface of the first solid electrolyte and an upper surface of the second solid electrolyte; And
Forming a second working electrode separated from the first working electrode so as to contact both the upper surface of the first solid electrolyte and the upper surface of the second solid electrolyte; Containing, method of manufacturing an electrochemical sensor. The method of claim 11,
Forming a first charge current collector on the first working electrode; And
Forming a second charge collector on the second working electrode; further comprising, the method of manufacturing an electrochemical sensor. The method of claim 11,
The method of manufacturing an electrochemical sensor, wherein the first solid electrolyte includes a material having oxide ion conductivity, and the second solid electrolyte includes a material having hydrogen ion conductivity. The method of claim 11,
The second solid electrolyte is a method of manufacturing an electrochemical sensor using a material doped with barium. The method of claim 11,
The second solid electrolyte includes barium zirconate-cerate, which is simultaneously doped with yttrium (Y) and ytterbium (Yb) ions. A counter electrode, a first solid electrolyte and a second solid electrolyte arranged side by side on an upper surface of the counter electrode, a first working electrode and a second operation formed to contact both the upper surface of the first solid electrolyte and the upper surface of the second solid electrolyte Using an electrochemical sensor including an electrode,
Measuring a first current value between the first working electrode and the counter electrode;
Measuring a second current value between the second working electrode and the counter electrode; And
Using the first current value and the second current value, determining the type of gas in which an oxidation reaction occurs in the first working electrode and the second working electrode; including, gas detection method of an electrochemical sensor . The method of claim 16,
Applying a first potential difference between the first working electrode and the counter electrode, and applying a second potential difference different from the first potential difference between the second working electrode and the counter electrode; further comprising, of the electrochemical sensor Gas detection method. The method of claim 17,
The first working electrode and the second working electrode promote an oxidation reaction of a plurality of gases including a first gas and a second gas,
The first potential difference is a potential difference at which the oxidation reaction of the first gas is accelerated,
The second potential difference is a potential difference at which an oxidation reaction of the second gas is accelerated, the gas detection method of an electrochemical sensor.

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