Gas tightness testing device for solid oxide batteries

Abstract

This invention discloses a gas tightness testing device for solid oxide batteries, comprising: a ceramic oxygen pump located at the top, a second electrolyte layer located at the bottom, and a sealing element located between the ceramic oxygen pump and the second electrolyte layer. The ceramic oxygen pump is composed of a first porous electrode, a first electrolyte layer, and a second porous electrode stacked sequentially. The sealing element, the first electrolyte layer, and the second electrolyte layer enclose a chamber, in which the second porous electrode is located. The positive terminal of a constant voltage source is connected to the positive terminal of an ammeter, and the negative terminal of the ammeter is connected to the first porous electrode of the ceramic oxygen pump via a metal wire. The negative terminal of the constant voltage source is connected to the second porous electrode of the ceramic oxygen pump via a metal wire. The first porous electrode, the first electrolyte layer, the second porous electrode, the constant voltage source, and the ammeter form a circuit. This invention's gas tightness testing device for solid oxide batteries solves the shortcomings of existing gas tightness testing methods, such as high cost, low accuracy and reliability, and difficulty in in-situ testing.

Description

Technical Field

[0001] This invention relates to the technical field of solid oxide batteries, and more particularly to a device for detecting the airtightness of solid oxide batteries. Background Technology

[0002] Solid oxide batteries (SOCs) are all-solid-state energy conversion devices based on ceramic electrolyte membranes. Through high-temperature sealing with a sealing element, individual cells are connected in series with current collectors, connectors, and other components to form a stack. The airtightness of the sealing element is one of the bottlenecks restricting the development of solid oxide batteries. Currently, physical methods such as differential pressure and pressure drop are generally used to test the airtightness of the sealing element. These methods require the construction of complex testing devices and are not easy to guarantee the uniformity of pressure application and the accuracy of the results. Multiple experiments are generally required to reduce errors. Summary of the Invention

[0003] The purpose of this invention is to provide a gas tightness testing device for solid oxide batteries. This device can quantitatively characterize the sealing gas tightness of the sealing component in situ, and has low testing cost, high accuracy and high reliability.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a gas tightness detection device for a solid oxide battery, comprising: a ceramic oxygen pump located above, a second electrolyte layer located below, and a sealing member located between the ceramic oxygen pump and the second electrolyte layer. The ceramic oxygen pump is composed of a first porous electrode, a first electrolyte layer, and a second porous electrode stacked sequentially. The sealing member, the first electrolyte layer, and the second electrolyte layer enclose a chamber, and the second porous electrode is located in the chamber.

[0005] Both the first and second electrolyte layers are ceramic materials with oxygen ion conductivity. The first and second porous electrodes are electronically conductive materials or oxygen-ion / electronically conductive mixed conductive materials. The oxygen-ion / electronically conductive mixed conductive material is La. 0.8 Sr 0.2 MnO 3-d ;

[0006] The thickness of the first electrolyte layer and the second electrolyte layer is 10~1000 micrometers, the thickness of the first porous electrode and the second porous electrode is 10~1000 micrometers, the height of the chamber is 50~2000 micrometers, and the thickness of the seal is 50~2000 micrometers.

[0007] It also includes: a constant voltage source and an ammeter. The positive terminal of the constant voltage source is connected to the positive terminal of the ammeter. The negative terminal of the ammeter is connected to the first porous electrode of the ceramic oxygen pump through a metal wire. The negative terminal of the constant voltage source is connected to the second porous electrode of the ceramic oxygen pump through a metal wire. The first porous electrode, the first electrolyte layer, the second porous electrode, the constant voltage source, and the ammeter form a circuit.

[0008] The following are further improvements to the above technical solution:

[0009] 1. In the above scheme, the ceramic material with oxygen ion conductivity is yttrium-stabilized zirconium oxide, scandium-stabilized zirconium oxide, samarium-doped cerium oxide, gadolinium-doped cerium oxide, strontium-magnesium co-doped gallium-lanthanum oxide, erbium-stabilized bismuth oxide, barium zirconate doped, or barium cerate doped, wherein 0 <x<1,0<y<1,0<δ<1。

[0010] 2. In the above scheme, the thickness of the first electrolyte layer and the second electrolyte layer is 20~600 micrometers.

[0011] 3. In the above scheme, the thickness of the first porous electrode and the second porous electrode is 20~500 micrometers.

[0012] 4. In the above scheme, the height of the chamber is 200~1000 micrometers.

[0013] 5. In the above scheme, the thickness of the sealing element is 200~1000 micrometers.

[0014] 6. In the above scheme, the thickness of the sealing element is 200~1000 micrometers.

[0015] 7. In the above scheme, the metal wire is a silver wire or a platinum wire.

[0016] 8. In the above scheme, the output voltage of the constant voltage source is 0.1~0.3 V.

[0017] 9. In the above scheme, the ceramic oxygen pump operates at 500~850℃.

[0018] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0019] 1. The airtightness testing device for solid oxide batteries of the present invention directly reflects the gas leakage rate of the sealing component by displaying the steady-state current value of the ammeter. The lower the steady-state current value, the higher the airtightness of the sealing component. Through constant potential polarization method, this device can accurately detect the airtightness of the solid oxide battery stack sealing component in situ, and has the advantages of low cost and simple operation.

[0020] 2. The present invention relates to a gas tightness detection device for solid oxide batteries. This invention utilizes a glass sealing element for an electrochemical oxygen pump battery. It leverages the reaction kinetic equilibrium reached by the oxygen reduction reaction occurring at the electrodes of the oxygen pump battery at high temperatures, pumping oxygen out of the sealed chamber and oxygen leaking into the sealed chamber from the outside. The steady-state current generated by the reaction is monitored using an electrochemical workstation, and the magnitude of this steady-state current reflects the degree of leakage of the sealing element. The leakage amount can be calculated by combining Faraday's law of electrolysis and the current detected by the electrochemical workstation. Using this method and device, quantitative characterization of the leakage rate of solid oxide batteries under different temperatures and pressures can be achieved. For example, under a high temperature of 800℃ and a pressure of 0.23 kPa, the gas tightness test results for a ceramic oxygen pump device sealed with the sealing element show an extremely low constant potential polarization current plateau, with a steady-state current of only 50 nA, on the order of nanoamperes. Based on Faraday's law of electrolysis and the electrode reaction equation, the leakage amount corresponding to this current can be calculated to be 2.6 × 10⁻⁶. -7 ml 3 ·min -1 ·cm -1 This is lower than the 0.04 ml leakage limit for sealing materials specified in the U.S. Department of Energy's SECA program. 3 ·min -1 ·cm -1 This demonstrates the excellent sealing capability of seal 200 under the specified temperature, pressure, and pressure conditions. Furthermore, the short time to reach the oxygen pump current plateau indicates a rapid and efficient detection capability. Therefore, this method can be used to quantitatively detect the sealing performance of solid oxide batteries during operation. Attached Figure Description

[0021] Appendix Figure 1 This is a schematic diagram of the airtightness testing device for solid oxide batteries of the present invention.

[0022] Appendix Figure 2 The sealing leakage current curves of the glass seal of the present invention at 800℃, 0 and 0.23 kPa are shown.

[0023] In the above attached diagram: 1. Ceramic oxygen pump; 2. Second electrolyte layer; 3. Seal; 4. First porous electrode; 5. Second porous electrode; 6. First electrolyte layer; 7. Chamber; 8. Constant voltage source; 9. Ammeter. Detailed Implementation

[0024] The present patent can be further understood through the specific embodiments given below, but they are not intended to limit the present patent.

[0025] Example 1: A gas tightness testing device for a solid oxide battery, comprising: a ceramic oxygen pump 1 located above, a second electrolyte layer 2 located below, and a sealing member 3 located between the ceramic oxygen pump 1 and the second electrolyte layer 2. The ceramic oxygen pump 1 is composed of a first porous electrode 4, a first electrolyte layer 6, and a second porous electrode 5 stacked sequentially. The sealing member 3, the first electrolyte layer 6, and the second electrolyte layer 2 form a chamber 7, and the second porous electrode 5 is located in the chamber 7.

[0026] Both the first electrolyte layer 6 and the second electrolyte layer 2 are ceramic materials with oxygen ion conductivity. The first porous electrode 4 and the second porous electrode 5 are electronically conductive materials or oxygen-ion-electronic hybrid conductive materials. The oxygen-ion-electronic hybrid conductive material is La. 0.8 Sr 0.2 MnO 3-d This is more conducive to the occurrence of oxygen reduction process on the oxygen pump electrode;

[0027] The thickness of the first electrolyte layer 6 and the second electrolyte layer 2 is 10~1000 micrometers, the thickness of the first porous electrode 4 and the second porous electrode 5 is 10~1000 micrometers, the height of the chamber 7 is 50~2000 micrometers, and the thickness of the sealing element 3 is 50~2000 micrometers.

[0028] It also includes: a constant voltage source 8 and an ammeter 9. The positive terminal of the constant voltage source 8 is connected to the positive terminal of the ammeter 9. The negative terminal of the ammeter 9 is connected to the first porous electrode 4 of the ceramic oxygen pump 1 through a metal wire. The negative terminal of the constant voltage source 8 is connected to the second porous electrode 5 of the ceramic oxygen pump 1 through a metal wire. The first porous electrode 4, the first electrolyte layer 6, the second porous electrode 5, the constant voltage source 8, and the ammeter 9 form a circuit.

[0029] The aforementioned ceramic material with oxygen ion conductivity is a yttrium oxide-stabilized zirconium oxide-strontium magnesium co-doped gallium-lanthanum (La) 1- x Sr x Ga 1-y Mg y O 3−d , of which 0 <x<1,0<y<1,0<δ<1。

[0030] The thickness of the first electrolyte layer 6 and the second electrolyte layer 2 is 100 micrometers, and the thickness of the first porous electrode 4 and the second porous electrode 5 is 100 micrometers.

[0031] The height of the aforementioned chamber 7 is 500 micrometers, and the thickness of the aforementioned seal 3 is 500 micrometers.

[0032] The aforementioned metal wire is a silver wire, and the output voltage of the aforementioned constant voltage source 8 is 0.2 V.

[0033] The output voltage of the aforementioned constant voltage source 8 is 0.1V.

[0034] The ceramic oxygen pump 1 described above operates at 550℃.

[0035] Example 2: A gas tightness testing device for a solid oxide battery, comprising: a ceramic oxygen pump 1 located above, a second electrolyte layer 2 located below, and a sealing member 3 located between the ceramic oxygen pump 1 and the second electrolyte layer 2. The ceramic oxygen pump 1 is composed of a first porous electrode 4, a first electrolyte layer 6, and a second porous electrode 5 stacked sequentially. The sealing member 3, the first electrolyte layer 6, and the second electrolyte layer 2 form a chamber 7, and the second porous electrode 5 is located in the chamber 7.

[0036] Both the first electrolyte layer 6 and the second electrolyte layer 2 are ceramic materials with oxygen ion conductivity. The first porous electrode 4 and the second porous electrode 5 are electronically conductive materials or oxygen-ion-electronic hybrid conductive materials. The oxygen-ion-electronic hybrid conductive material is La. 0.8 Sr 0.2 MnO 3-d This is more conducive to the occurrence of oxygen reduction process on the oxygen pump electrode;

[0037] The thickness of the first electrolyte layer 6 and the second electrolyte layer 2 is 10~1000 micrometers, the thickness of the first porous electrode 4 and the second porous electrode 5 is 10~1000 micrometers, the height of the chamber 7 is 50~2000 micrometers, and the thickness of the sealing element 3 is 50~2000 micrometers.

[0038] It also includes: a constant voltage source 8 and an ammeter 9. The positive terminal of the constant voltage source 8 is connected to the positive terminal of the ammeter 9. The negative terminal of the ammeter 9 is connected to the first porous electrode 4 of the ceramic oxygen pump 1 through a metal wire. The negative terminal of the constant voltage source 8 is connected to the second porous electrode 5 of the ceramic oxygen pump 1 through a metal wire. The first porous electrode 4, the first electrolyte layer 6, the second porous electrode 5, the constant voltage source 8, and the ammeter 9 form a circuit.

[0039] The aforementioned ceramic material with oxygen ion conductivity is strontium magnesium co-doped gallium lanthanum La. 1-x Sr x Ga 1-y Mg y O 3−d , of which 0 <x<1,0<y<1,0<δ<1。

[0040] The thickness of the first electrolyte layer 6 and the second electrolyte layer 2 is 150 micrometers, and the thickness of the first porous electrode 4 and the second porous electrode 5 is 150 micrometers.

[0041] The height of the aforementioned chamber 7 is 300 micrometers, and the thickness of the aforementioned seal 3 is 300 micrometers.

[0042] The aforementioned metal wire is a platinum wire, and the output voltage of the aforementioned constant voltage source 8 is 0.15V.

[0043] The ceramic oxygen pump 1 described above operates at 600℃.

[0044] The output voltage of the constant voltage source 8 is 0.3V.

[0045] As attached Figure 2 Figures (a) and (b) show the airtightness test results of the sealant 200 at 800℃ and load pressures of 0 and 0.23 kPa. A constant voltage of 0.3V was applied across the ceramic oxygen pump. Due to leakage between the inside and outside of the chamber, the pumped oxygen reached equilibrium with the oxygen diffused into the chamber. After stabilization, a constant current plateau of 0.595mA was observed, reaching the milliampere level. A higher current value indicates a higher leakage rate and a poorer sealing effect. Based on Faraday's law of electrolysis and the electrode reaction equation, 0.595mA corresponds to a leakage amount of 3.0 × 10⁻⁶. -3 ml 3 ·min -1 ·cm -1 .

[0046] After applying a pressure of 0.23 kPa, the pressure on seal 200 strengthens the bond between the flowing glass and adjacent components at this temperature. The interface is smooth with no obvious defects, preventing external oxygen from diffusing into the cavity, resulting in extremely low oxygen ion migration rates. Therefore, when stable, the constant potential polarization current plateau is extremely low, approximately 10% lower than the limiting current value of the unloaded pressure group sealing at the same temperature. 4 The current is on the order of magnitude, only 50 nA, which is in the nanoampere range. This translates to a current of 2.6 × 10⁻⁶. -7 ml 3 ·min -1 ·cm -1 This demonstrates the excellent sealing capability of sealant 200 under these temperature and pressure conditions. Therefore, this method can be used to quantitatively determine the airtightness of the sealant when sealing a solid oxide battery.

[0047] When using the above-mentioned solid oxide battery airtightness testing device, the steady-state current value displayed by its ammeter directly reflects the gas leakage rate of the seal. The lower the steady-state current value, the higher the airtightness of the seal. Through the constant potential polarization method, this device can accurately detect the airtightness of the solid oxide battery stack seal in situ, and has the advantages of low cost and easy operation.

[0048] Furthermore, it utilizes the oxygen reduction reaction occurring at the electrodes of the oxygen pump battery at high temperatures to pump out oxygen from the sealed chamber and oxygen leaking into the sealed chamber from the outside, reaching a reaction kinetic equilibrium. This equilibrium state is then monitored by an electrochemical workstation to detect the steady-state current generated by the reaction; the magnitude of this steady-state current reflects the degree of leakage of the seal. The leakage amount can be calculated by combining Faraday's law of electrolysis and the current detected by the electrochemical workstation. Using this method and device, quantitative characterization of the leakage rate of solid oxide batteries under different temperatures and pressures can be achieved. For example, under a high temperature of 800℃ and a pressure of 0.23 kPa, the airtightness test results of a ceramic oxygen pump device sealed with a seal show that the constant potential polarization current plateau is extremely low, with a steady-state current of only 50 nA, on the order of nanoamperes. Based on Faraday's law of electrolysis and the electrode reaction equation, the leakage amount corresponding to this current can be calculated to be 2.6 × 10⁻⁶. -7 ml 3 ·min -1 ·cm -1 This is lower than the 0.04 ml leakage limit for sealing materials specified in the U.S. Department of Energy's SECA program. 3 ·min -1 ·cm -1 This demonstrates the excellent sealing capability of seal 200 under the specified temperature, pressure, and pressure conditions. Furthermore, the short time to reach the oxygen pump current plateau indicates a rapid and efficient detection capability. Therefore, this method can be used to quantitatively detect the sealing performance of solid oxide batteries during operation.

[0049] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A device for detecting the airtightness of a solid oxide battery, characterized in that: include: The ceramic oxygen pump (1) is located above, the second electrolyte layer (2) is located below, and the sealing element (3) is located between the ceramic oxygen pump (1) and the second electrolyte layer (2). The ceramic oxygen pump (1) is composed of a first porous electrode (4), a first electrolyte layer (6), and a second porous electrode (5) stacked in sequence. The sealing element (3) and the first electrolyte layer (6) and the second electrolyte layer (2) form a chamber (7). The second porous electrode (5) is located in the chamber (7). The first electrolyte layer (6) and the second electrolyte layer (2) are both ceramic materials with oxygen ion conductivity. The first porous electrode (4) and the second porous electrode (5) are electronically conductive materials or oxygen-ion-electronic mixed conductive materials. The oxygen-ion-electronic mixed conductive material is La. 0.8 Sr 0.2 MnO 3-d ; The thickness of the first electrolyte layer (6) and the second electrolyte layer (2) is 10~1000 micrometers, the thickness of the first porous electrode (4) and the second porous electrode (5) is 10~1000 micrometers, the height of the chamber (7) is 50~2000 micrometers, and the thickness of the sealing element (3) is 50~2000 micrometers. It also includes a constant voltage source (8) and an ammeter (9). The positive terminal of the constant voltage source (8) is connected to the positive terminal of the ammeter (9). The negative terminal of the ammeter (9) is connected to the first porous electrode (4) of the ceramic oxygen pump (1) through a metal wire. The negative terminal of the constant voltage source (8) is connected to the second porous electrode (5) of the ceramic oxygen pump (1) through a metal wire. The first porous electrode (4), the first electrolyte layer (6), the second porous electrode (5), the constant voltage source (8), and the ammeter (9) form a circuit.

2. The airtightness testing device for solid oxide batteries according to claim 1, characterized in that: The ceramic material with oxygen ion conductivity is yttrium-stabilized zirconium oxide (ZrO2). 1-x Y x O 2−d Scandium oxide stabilized zirconium oxide (Zr) 1- x Sc x O 2−d ), samarium oxide-doped cerium oxide (Ce) 1-x Sm x O 2−d ), gadolinium oxide-doped cerium oxide (Ce) 1-x Gd x O 2−d ), Strontium magnesium co-doped gallium lanthanum (La) 1-x Sr x Ga 1-y Mg y O 3−d Erbium-stabilized bismuth oxide (Er) x Bi 2-x O 3−d ), barium zirconate doped (BaZr) 1-x Y x O 3−d ) or doped with barium cerate (BaCe) 1-x Y x O 3−d ), where 0 <x<1,0<y<1,0<δ<1。 3. The airtightness testing device for solid oxide batteries according to claim 1, characterized in that: The thickness of the first electrolyte layer (6) and the second electrolyte layer (2) is 20~600 micrometers.

4. The airtightness testing device for solid oxide batteries according to claim 1, characterized in that: The thickness of the first porous electrode (4) and the second porous electrode (5) is 20~500 micrometers.

5. The airtightness testing device for solid oxide batteries according to claim 1, characterized in that: The height of the chamber (7) is 200~1000 micrometers.

6. The airtightness testing device for solid oxide batteries according to claim 1, characterized in that: The thickness of the seal (3) is 200~1000 micrometers.

7. The airtightness testing device for solid oxide batteries according to claim 1, characterized in that: The thickness of the seal (3) is 200~1000 micrometers.

8. The airtightness testing device for solid oxide batteries according to claim 1, characterized in that: The metal wire is a silver wire or a platinum wire.

9. The airtightness testing device for solid oxide batteries according to claim 1, characterized in that: The output voltage of the constant voltage source (8) is 0.1~0.3 V.

10. The airtightness testing device for solid oxide batteries according to claim 1, characterized in that: The ceramic oxygen pump (1) operates at 500~850℃.

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