Tensile test device and method for testing interfacial strength of electrode / electrolyte of solid oxide fuel cell

Abstract

The invention provides a tensile test device and method for testing the interfacial strength of an electrode / electrolyte of a solid oxide fuel cell, and the tensile test device comprises a pull rod (1), one end of the pull rod (1) is connected with an upper clamp of a tensile test machine, and the other end of the pull rod (1) is connected with an electrode; the square tube (2) is fixed through a tensile testing machine clamp, and one surface of the square tube (2) is provided with an opening. By applying the technical scheme, the problem of low test sensitivity of a tensile test device for testing the interface strength of the electrode / electrolyte of the solid oxide fuel cell in the prior art can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of fuel cell testing, in particular to a tensile testing device and method for testing the interface strength of a solid oxide fuel cell electrode / electrolyte. Background Art

[0002] Solid oxide fuel cell (SOFC) is an energy conversion device that can directly convert chemical energy in fuel into electrical energy. It has a wide range of fuel options, including hydrogen, natural gas, coal-to-gas, biomass gas, methanol and other fuels. SOFC's power generation efficiency and combined heat and power efficiency are as high as 70-85%. When using hydrocarbons as fuel, SOFC's high conversion efficiency greatly reduces carbon dioxide emissions; when using green hydrogen as fuel, it will not emit carbon dioxide and will not pollute the air.

[0003] In order to ensure the structural reliability of SOFC and prevent the electrode / electrolyte interface from cracking and delamination due to external forces, the electrode / electrolyte interface must have sufficient mechanical strength. Tensile test is a common method to measure interface strength, but in existing tensile devices, two tension rods are usually used to bond the battery for testing, which can easily cause the direction of the tension to deviate from the axis of the sample. On the one hand, this will cause the fracture to occur in other parts besides the interface, affecting the accuracy of the experimental results; on the other hand, the shear force generated may directly cause the weaker electrode to peel off first, making it difficult to obtain the true interface strength. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a tensile test device and method for testing the electrode / electrolyte interface strength of a solid oxide fuel cell, so as to solve the problems of sample damage and inaccurate test results in the tensile test device of the electrode / electrolyte interface strength in the prior art.

[0005] To achieve the above object, the present invention adopts the following technical solution: a tensile test device for testing the electrode / electrolyte interface strength of a solid oxide fuel cell, comprising: A pull rod (1), one end of the pull rod (1) being connected to a clamp on a tensile testing machine, and the other end of the pull rod (1) being connected to an electrode; A square tube (2), wherein the square tube (2) is fixed by a clamp of a tensile testing machine, and one side of the square tube (2) is provided with an opening.

[0006] In a preferred embodiment, the two ends of the structure of the pull rod (1) are cylindrical and rectangular respectively.

[0007] In a preferred embodiment, in the pull rod (1), one end in a cylindrical shape is connected to the electrode, and one end in a rectangular shape is connected to the clamp of the tensile testing machine.

[0008] In a preferred embodiment, the opening of the square tube (2) is rectangular.

[0009] In a preferred embodiment, the transverse width of the opening of the square tube (2) is greater than the width of the electrode and smaller than the width of the battery, and the longitudinal length of the square tube (2) is greater than the width of the battery.

[0010] The present invention also provides a tensile test method for testing the interface strength of a solid oxide fuel cell electrode / electrolyte. The steps of using the tensile test device for testing the interface strength of a solid oxide fuel cell electrode / electrolyte are as follows: Step 1: Use glue to connect the battery electrode and the tie rod to prepare a sample; Step 2: Connect the square tube (2) to the lower fixture of the tensile testing machine, with the opening surface of the square tube (2) facing upward.

[0011] Step 3: insert the battery part of the sample in step 1 into the inner space of the square tube (2) from the opening of the square tube, and connect the rectangular end of the pull rod to the clamp on the tensile testing machine; Step 4: The tensile testing machine drives the sample to move upward. During this process, the battery cell will generate tensile strain due to the obstruction of the square tube (2). At the same time, the tensile testing machine will record the tensile data during this process.

[0012] In a preferred embodiment, the type of the glue is ethyl cyanoacrylate or acrylate, epoxy resin glue.

[0013] In a preferred embodiment, the electrode of the battery is a cathode or an anode of a solid oxide fuel cell.

[0014] Compared with the prior art, the present invention has the following beneficial effects: the test sample uses only one pull rod to adhere the electrode, and the square tube and the test sample are not in direct contact initially, thereby avoiding the risk of damaging the electrode when the clamp clamps the sample; the contact surfaces of the sample and the square tube can be adjusted to be horizontal before testing to ensure that the direction of the force coincides with the axis of the sample, thereby avoiding fracture occurring outside the interface and improving the accuracy of the data. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of a three-dimensional structure of a pull rod provided in an embodiment of the present invention; Figure 2 A schematic diagram of a three-dimensional structure of a square tube provided in an embodiment of the present invention; Figure 3 A schematic diagram of the overall three-dimensional structure of a tensile testing device for electrode / electrolyte interface strength testing provided by an embodiment of the present invention; Figure 4 In Example 1, La0.8 Sr 0.2 MnO 3-δ (LSM) tensile strength curve of sintered electrode; Figure 5 In Example 2, La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF) Sintered electrode tensile strength curve; Figure 6 In Example 3, La 0.6 Sr 0.4 CoO 3-δ (LSC) tensile strength curve of sintered electrode. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0017] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0018] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application; as used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations.

[0019] The tensile test device and test method for testing the solid oxide fuel cell electrode / electrolyte interface strength provided by the present invention are now described.

[0020] (1) See Figure 1 , apply a layer of ethyl cyanoacrylate glue on the cylindrical end surface of the tie rod, then adhere the tie rod to the electrode surface, and wait for the glue to dry to reach the optimal strength; (2) See Figure 2 , use the lower fixture of the tensile testing machine to fix the square tube 2, with the opening surface of the square tube 2 facing upward horizontally; (3) Use the fixture on the material testing machine to fix the pull rod of the tensile strength test sample obtained in step (1) while keeping the battery cell horizontal. See the schematic diagram for details. Figure 3 ; (4) Start the test machine, which drives the sample 31 to move upward and away from the square tube 32. When the sample moves to contact the square tube 32, the movement of the sample 31 is hindered, and the interaction between the sample 31 and the square tube 2 is transferred to the electrode / electrolyte interface with weaker strength through the battery cell. The test machine continues to drive the sample 31 upward, and the electrode and the battery cell are peeled off, thereby obtaining a tensile curve of the electrode / electrolyte interface strength.

[0021] Application Example 1 Figure 4 For use Figure 3 The tensile curve of the LSM electrode sintered at 1100 °C measured by the device shown. The electrolyte of the battery is (Y2O3) 0.08 (ZrO2) 0.92 (8-YSZ) was sintered at 1450 °C; then a layer of Ce was spin-coated on the electrolyte surface. 0.2 G 0.8 O 2-δ (GDC) isolation layer, sintered at 1200 ℃; LSM electrode was screen-printed on the surface of the GDC isolation layer and then sintered at 1100 ℃.

[0022] From the tensile curve, it can be seen that the electrode breaks suddenly. The tensile curve is basically linear in the elastic stage, that is, the stress is proportional to the strain, which conforms to Hooke's law. This shows that the electrode breaks brittlely in the tensile test, which is consistent with the material properties.

[0023] Application Example 2 Figure 5 For use Figure 3 The tensile curve of the LSCF electrode sintered at 1000 °C measured by the device shown. The battery electrolyte is 8-YSZ sintered at 1450 °C; then a GDC isolation layer is spin-coated on the electrolyte surface and sintered at 1200 °C; the LSCF electrode is screen-printed on the surface of the GDC isolation layer and then sintered at 1000 °C.

[0024] The tensile curve conforms to Hooke's law, the fracture conforms to the material properties, and the data obtained from the samples have good repeatability.

[0025] Application Example 3 Figure 6 For use Figure 3 The tensile curve of the LSC electrode sintered at 950 °C measured by the device shown. The battery electrolyte is 8-YSZ sintered at 1450 °C; then a GDC isolation layer is spin-coated on the electrolyte surface and sintered at 1200 °C; the LSC electrode is screen-printed on the surface of the GDC isolation layer and then sintered at 950 °C.

[0026] Compared with Example 1 and Example 2, the LSC electrode strength in Example 3 is weaker, indicating that the present invention is also applicable to the strength test of weak electrode / electrolyte interface.

[0027] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A tensile test device for testing the electrode / electrolyte interface strength of a solid oxide fuel cell, characterized in that: include: A pull rod (1), one end of the pull rod (1) being connected to a clamp on a tensile testing machine, and the other end of the pull rod (1) being connected to an electrode; A square tube (2), wherein the square tube (2) is fixed by a clamp of a tensile testing machine, and one side of the square tube (2) is provided with an opening.

2. A tensile test device for testing the interface strength of a solid oxide fuel cell electrode / electrolyte according to claim 1, characterized in that: The two ends of the structure of the pull rod (1) are respectively cylindrical and rectangular.

3. A tensile test device for testing the interface strength of a solid oxide fuel cell electrode / electrolyte according to claim 2, characterized in that: In the pull rod (1), one end in a cylindrical shape is connected to the electrode, and one end in a rectangular shape is connected to the clamp of the tensile testing machine.

4. A tensile test device for testing the solid oxide fuel cell electrode / electrolyte interface strength according to claim 1, characterized in that: The opening of the square tube (2) is rectangular.

5. A tensile test device for testing the solid oxide fuel cell electrode / electrolyte interface strength according to claim 4, characterized in that: The transverse width of the opening of the square tube (2) is greater than the width of the electrode and smaller than the width of the battery, and the longitudinal length of the square tube (2) is greater than the width of the battery.

6. A tensile test method for testing the electrode / electrolyte interface strength of a solid oxide fuel cell, characterized in that Using a tensile test device for testing the solid oxide fuel cell electrode / electrolyte interface strength according to any one of claims 1 to 5, the steps are as follows: Step 1: Use glue to connect the battery electrode and the tie rod to prepare a sample; Step 2: Connect the square tube (2) to the lower fixture of the tensile testing machine, with the opening surface of the square tube (2) facing upwards; Step 3: insert the battery part of the sample in step 1 into the inner space of the square tube (2) from the opening of the square tube, and connect the rectangular end of the pull rod to the clamp on the tensile testing machine; Step 4: The tensile testing machine drives the sample to move upward. During this process, the battery cell will generate tensile strain due to the obstruction of the square tube (2). At the same time, the tensile testing machine will record the tensile data during this process.

7. A tensile test method for testing the solid oxide fuel cell electrode / electrolyte interface strength according to claim 6, characterized in that: The type of the glue is ethyl cyanoacrylate or acrylate, epoxy resin glue.

8. A tensile test method for testing the electrode / electrolyte interface strength of a solid oxide fuel cell according to claim 6, characterized in that: The electrode of the battery is the cathode or anode of a solid oxide fuel cell.

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