Preparation method of hydrogen permeation ceramic with gas selectivity and hydrogen permeation ceramic
By preparing hydrogen permeable ceramics and applying them to the cover plate of hydrogen sensors, the problem of insufficient selectivity of hydrogen for semiconductor gas sensors is solved, high selectivity detection of hydrogen is achieved, and the safety of lithium batteries is improved.
Patent Information
- Application Number
- CN202510482639.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-17
- Publication Date
- 2025-07-22
AI Technical Summary
Existing semiconductor gas sensors have low selectivity for gases in lithium battery packs, and cannot effectively distinguish between hydrogen and other interfering gases, resulting in a decrease in detection efficiency and a risk of fire or explosion.
By preparing a hydrogen permeable ceramic, the pore size is gradually reduced by ball milling, drying, sieving, multiple soaking, drying and sintering, making it selective to hydrogen and preventing other gases from infiltration, and preparing a cover plate for hydrogen sensor.
It realizes high selective detection of hydrogen, effectively prevents the infiltration of other interfering gases, improves the detection efficiency of semiconductor gas sensors, and ensures the safety of lithium batteries.
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Figure CN120349172A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical fields of gas sensors and ceramic filtration, and more particularly to a method for preparing a hydrogen-permeable ceramic with gas selectivity and the hydrogen-permeable ceramic. Background Art
[0002] When lithium thermal runaway occurs, a large amount of heat is generated and a large amount of combustible gases are released, such as CO, H2, C2H4, CH4, CO2, etc., resulting in a sharp rise in the internal pressure of the battery pack, and it is very likely to cause a fire or explosion. To ensure life safety, real-time monitoring is required, and gas detection is one of the solutions.
[0003] Semiconductor gas sensors are widely used due to their high sensitivity and low cost. However, due to the low gas selectivity of the materials used in current semiconductor gas sensors and the presence of many interfering gases in the battery pack, such as micro-leakage vapors of electrolytes (dimethyl carbonate DMC, ethyl methyl carbonate EMC, etc.) and VOC (Volatile Organic Compounds) gases released by silicone sealants, the detection efficiency of semiconductor gas sensors is reduced. Summary of the Invention
[0004] In view of the above problems, the present disclosure provides a method for preparing a hydrogen-permeable ceramic with gas selectivity and the hydrogen-permeable ceramic.
[0005] According to a first aspect of the present disclosure, there is provided a method for preparing a hydrogen-permeable ceramic with gas selectivity, including: placing alumina, magnesia, iron oxide, zinc oxide, corn starch, methyl cellulose, polyethylene glycol, glycerol, and water in a ball milling device for ball milling to obtain a ceramic slurry; drying and sieving the above ceramic slurry and then pressing it into a green ceramic body, and sintering the above green ceramic body to obtain a breathable ceramic; performing the following steps on the above breathable ceramic in a cycle until the number of sintering times reaches a first predetermined number: first soaking the above breathable ceramic in a mixed solution of hydrogen-containing silicone oil and ethyl acetate, and then drying the breathable ceramic taken out from the above mixed solution to obtain a dried breathable ceramic, wherein the process of first soaking the above breathable ceramic and then drying the above breathable ceramic needs to be cycled a second predetermined number of times; sintering the above dried breathable ceramic to obtain a sintered ceramic sheet; using the sintered ceramic sheet with the above first predetermined number of times as a hydrogen-permeable ceramic with gas selectivity.
[0006] According to an embodiment of the present disclosure, the above first predetermined number includes 1 to 3 times; the above second predetermined number includes 1 to 5 times.
[0007] According to an embodiment of the present disclosure, first immerse the above-mentioned breathable ceramic in a mixed solution of hydrogen-containing silicone oil and ethyl acetate, and then dry the breathable ceramic taken out from the above-mentioned mixed solution, including: immersing the above-mentioned breathable ceramic in the above-mentioned mixed solution for 5 to 10 minutes, and then drying the breathable ceramic taken out from the above-mentioned mixed solution at 80 °C for a first predetermined duration.
[0008] According to an embodiment of the present disclosure, the mass ratio of the hydrogen-containing silicone oil to the ethyl acetate in the above-mentioned mixed solution is 6:4 to 9:1.
[0009] According to an embodiment of the present disclosure, sintering the above-mentioned dried breathable ceramic includes: heating to 500 °C at a heating rate of 2 °C / min to 5 °C / min in an air atmosphere, and holding at 500 °C for a second predetermined duration, and then naturally cooling to a predetermined temperature.
[0010] According to an embodiment of the present disclosure, sintering the above-mentioned green ceramic body to obtain a breathable ceramic includes: heating the above-mentioned green ceramic body to 500 °C at a heating rate of 1 °C / min to 2 °C / min in an air atmosphere, holding at 500 °C for a third predetermined duration; then heating to 1500 °C to 1600 °C at a heating rate of 1 °C / min to 2 °C / min, holding at 1500 °C to 1600 °C for 1 to 3 hours; and then cooling to the above-mentioned predetermined temperature at a cooling rate of 1 °C / min to 2 °C / min to obtain the above-mentioned breathable ceramic.
[0011] According to an embodiment of the present disclosure, the mass of the above-mentioned alumina is 20 g to 30 g; the mass of the above-mentioned magnesia is 0.75 g to 1.25 g; the mass of the above-mentioned iron oxide is 0.15 g to 0.3 g; the mass of the above-mentioned zinc oxide is 3 g to 5 g; the mass of the above-mentioned corn starch is 3 g to 5 g; the mass of the above-mentioned methylcellulose is 0.2 g to 0.5 g; the volume of the above-mentioned polyethylene glycol is 2 mL to 3 mL; the volume of the above-mentioned glycerol is 2 mL to 3 mL; and the volume of the above-mentioned water is 100 mL to 150 mL.
[0012] The second aspect of the present disclosure also provides a hydrogen-permeable ceramic with gas selectivity, which is prepared by using the above-mentioned preparation method of the hydrogen-permeable ceramic with gas selectivity.
[0013] The third aspect of the present disclosure also provides a hydrogen sensor, including a cover plate, a ceramic base, gold wires, and a tin dioxide-based semiconductor device, wherein the material of the above-mentioned cover plate includes the above-mentioned hydrogen-permeable ceramic with gas selectivity.
[0014] The fourth aspect of the present disclosure also provides a method for preparing a hydrogen sensor, including: using a laser to cut a hydrogen-permeable ceramic with gas selectivity into a predetermined size, wherein the hydrogen-permeable ceramic with gas selectivity is prepared according to the above-mentioned method for preparing a hydrogen-permeable ceramic with gas selectivity; performing ceramic patch packaging on a tin dioxide-based semiconductor device, and using the hydrogen-permeable ceramic with a predetermined size as the cover plate for the ceramic patch packaging of the tin dioxide-based semiconductor device to obtain a hydrogen sensor.
[0015] According to an embodiment of the present disclosure, after ball milling, drying, sieving, and sintering the raw materials, the breathable ceramic is soaked, dried, and sintered multiple times with a mixed solution of hydrogen-containing silicone oil and ethyl acetate, which can gradually reduce the pore size of the hydrogen-permeable ceramic to obtain a hydrogen-permeable ceramic with gas selectivity. This hydrogen-permeable ceramic with gas selectivity can preferentially allow hydrogen to pass through and effectively prevent other interfering gases other than hydrogen from infiltrating. The semiconductor sensor prepared with this highly gas-selective hydrogen-permeable ceramic can have high selectivity for hydrogen and improve the detection efficiency of the semiconductor gas sensor. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Through the following description of the embodiments of the present disclosure with reference to the drawings, the above-mentioned content and other objects, features, and advantages of the present disclosure will become clearer. In the drawings:
[0017] Figure 1 Schematically shows a flowchart of a method for preparing a hydrogen-permeable ceramic with gas selectivity according to an embodiment of the present disclosure;
[0018] Figure 2 Schematically shows a structural diagram of a hydrogen sensor according to an embodiment of the present disclosure;
[0019] Figure 3 Schematically shows the response curves of the hydrogen-permeable ceramic with gas selectivity in the hydrogen sensor of the embodiment of the present disclosure and the breathable ceramic in the hydrogen sensor of the test example to hydrogen;
[0020] Figure 4 Schematically shows the response curves of the hydrogen-permeable ceramic with gas selectivity in the hydrogen sensor of the embodiment of the present disclosure and the breathable ceramic in the hydrogen sensor of the test example to DMC;
[0021] Figure 5 Schematically shows the response curves of the hydrogen-permeable ceramic with gas selectivity in the hydrogen sensor of the embodiment of the present disclosure and the breathable ceramic in the hydrogen sensor of the test example to EMC;
[0022] Figure 6 Schematically shows the response curves of the hydrogen-permeable ceramic with gas selectivity in the hydrogen sensor of the embodiment of the present disclosure and the breathable ceramic in the hydrogen sensor of the test example to silicone sealant gas;
[0023] Figure 7 Schematically shows the response curves of the hydrogen-permeable ceramic with gas selectivity in the hydrogen sensor according to an embodiment of the present disclosure and the gas-permeable ceramic in the hydrogen sensor of the test example to CO gas. Detailed implementation manners
[0024] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the following detailed description, for the sake of explanation, many specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure. However, it is obvious that one or more embodiments can also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present disclosure.
[0025] The terms used herein are merely for describing specific embodiments and are not intended to limit the present disclosure. The terms "including", "comprising" and the like used herein indicate the presence of the described features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.
[0026] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.
[0027] In the case of using expressions such as "at least one of A, B, and C, etc.", generally, it should be interpreted according to the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but not be limited to a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).
[0028] Figure 1 Schematically shows a flowchart of a preparation method of a hydrogen-permeable ceramic with gas selectivity according to an embodiment of the present disclosure.
[0029] As Figure 1 shown, the preparation method of the hydrogen-permeable ceramic with gas selectivity in this embodiment includes step S110 to step S140.
[0030] In step S110, alumina, magnesia, iron oxide, zinc oxide, corn starch, methyl cellulose, polyethylene glycol, glycerol, and water are placed in a ball milling device for ball milling to obtain a ceramic slurry.
[0031] In step S120, the ceramic slurry is dried, sieved, and then pressed into a green ceramic body, and the green ceramic body is sintered to obtain a breathable ceramic.
[0032] In step S130, the steps of soaking, drying, and sintering are cyclically performed on the breathable ceramic until the number of sintering times reaches a first predetermined number.
[0033] In some embodiments, the breathable ceramic is first soaked in a mixed solution of hydrogen-containing silicone oil and ethyl acetate, and then the breathable ceramic taken out from the mixed solution is dried to obtain a dried breathable ceramic, wherein the process of first soaking the breathable ceramic and then drying it needs to be cycled a second predetermined number of times; the dried breathable ceramic is sintered to obtain a sintered ceramic sheet.
[0034] In step S140, the sintered ceramic sheet with the first predetermined number of times is used as a hydrogen-permeable ceramic with gas selectivity.
[0035] In some embodiments, the mass of alumina includes 20 g to 30 g; the mass of magnesia includes 0.75 g to 1.25 g; the mass of iron oxide includes 0.15 g to 0.3 g; the mass of zinc oxide includes 3 g to 5 g; the mass of corn starch includes 3 g to 5 g; the mass of methyl cellulose includes 0.2 g to 0.5 g; the volume of polyethylene glycol (PEG) includes 2 mL to 3 mL; the volume of glycerol includes 2 mL to 3 mL; and the volume of water includes 100 mL to 150 mL.
[0036] In some embodiments, 20 g to 30 g of alumina, 0.75 g to 1.25 g of magnesia, 0.15 g to 0.3 g of iron oxide, 3 g to 5 g of zinc oxide, 3 g to 5 g of corn starch, 0.2 g to 0.5 g of methyl cellulose can be weighed, 2 mL to 3 mL of PEG600, 2 mL to 3 mL of glycerol, and 100 mL to 150 mL of water are measured into a 500 mL ball milling tank, and ball milled continuously at 300 rpm for 24 h to obtain a ceramic slurry.
[0037] In some embodiments, the slurry obtained in the above steps can be placed in an 80 °C oven and dried for 24 h to obtain ceramic powder; the ceramic powder is screened through a 100-mesh sieve to obtain ceramic powder with a particle size of 100 mesh; a predetermined mass of the 100-mesh particle size ceramic powder is weighed and pressed into shape by a ceramic powder press to obtain a green ceramic body. The predetermined mass can be adjusted adaptively according to actual needs.
[0038] In some embodiments, sintering a green ceramic body to obtain a breathable ceramic may include the following steps: heating the green ceramic body in an air atmosphere at a heating rate of 1 °C / min to 2 °C / min to 500 °C, holding at 500 °C for a third predetermined duration, such as 1 h; then heating at a heating rate of 1 °C / min to 2 °C / min to 1500 °C to 1600 °C, holding at 1500 °C to 1600 °C for 1 to 3 h; and subsequently cooling at a cooling rate of 1 °C / min to 2 °C / min to a predetermined temperature, such as to room temperature, to obtain the breathable ceramic.
[0039] In some embodiments, hydrogen-containing silicone oil and ethyl acetate can be uniformly mixed in a mass ratio of 6:4 to 9:1 to obtain a mixed solution. The breathable ceramic can be immersed in the mixed solution for 5 min to 10 min, taken out and dried at 80 °C for a first predetermined duration, such as 20 min. The process of first immersing and then drying can be repeated a second predetermined number of times, such as 1 to 5 times.
[0040] In some embodiments, the dried breathable ceramic that has been immersed and dried 1 to 5 times can be placed in a high-temperature sintering furnace, heated in an air atmosphere at a heating rate of 2 °C / min to 5 °C / min to 500 °C, held at 500 °C for a second predetermined duration, such as 2 h, and then naturally cooled to a predetermined temperature, such as to room temperature, to obtain a sintered ceramic sheet. This is the case of sintering once. For the dried breathable ceramic that has been sintered once and cooled to a predetermined temperature, the process of first immersing and then drying can be performed again. After immersing and drying 1 to 5 times, it is placed in a high-temperature sintering furnace again, heated in an air atmosphere at a heating rate of 2 °C / min to 5 °C / min to 500 °C, held at 500 °C for 2 h, and then naturally cooled to room temperature. This is the case of sintering twice. Until the first predetermined number of high-temperature sintering times, such as 1 to 3 times, that is, the above process of first immersing and drying 1 to 5 times and then sintering is repeated 1 to 3 times, a breathable ceramic with gas selectivity can be obtained.
[0041] According to the embodiments of the present disclosure, by circulating the operations of soaking, drying, and sintering multiple times, the pore size of the breathable ceramic can be reduced, thereby improving the selectivity of the breathable ceramic to hydrogen and obtaining a hydrogen-permeable ceramic with high hydrogen selectivity.
[0042] According to an embodiment of the present disclosure, after ball milling, drying, sieving, and sintering the raw materials, the breathable ceramic is soaked, dried, and sintered multiple times with a mixed solution of hydrogen-containing silicone oil and ethyl acetate, which can gradually reduce the pore size of the hydrogen-permeable ceramic to obtain a hydrogen-permeable ceramic with gas selectivity. This hydrogen-permeable ceramic with gas selectivity can preferentially allow hydrogen to pass through and effectively prevent other interfering gases other than hydrogen from infiltrating. The semiconductor sensor prepared using this hydrogen-permeable ceramic with high gas selectivity can have high selectivity for hydrogen, improving the detection efficiency of the semiconductor gas sensor.
[0043] An embodiment of the present disclosure also provides a hydrogen-permeable ceramic with gas selectivity, which is prepared by using the above-mentioned preparation method of the hydrogen-permeable ceramic with gas selectivity. The hydrogen-permeable ceramic with gas selectivity can preferentially allow hydrogen to pass through and effectively prevent other interfering gases from infiltrating, realizing real-time monitoring of hydrogen during the thermal runaway of lithium batteries.
[0044] An embodiment of the present disclosure also provides a hydrogen sensor, which can be as Figure 2 shown.
[0045] Figure 2 Schematically shows the structural diagram of the hydrogen sensor according to an embodiment of the present disclosure.
[0046] As Figure 2 shown, the hydrogen sensor includes a cover plate 1, a ceramic base 2, gold wires 3, and a tin dioxide-based semiconductor device 4. A gas-sensitive material 401 can be loaded on the tin dioxide-based semiconductor device 4, and the gas-sensitive material 401 is, for example, tin dioxide. The material of the cover plate 1 can be the above-mentioned hydrogen-permeable ceramic with gas selectivity. The hydrogen-permeable ceramic cover plate with gas selectivity preferentially allows hydrogen to pass through, prevents other interfering gases from infiltrating, improves the detection efficiency of the sensor, monitors the hydrogen in the lithium battery in real time, avoids fires or explosions, and ensures life safety.
[0047] An embodiment of the present disclosure also provides a preparation method of a hydrogen sensor for preparing the above-mentioned hydrogen sensor. The preparation method of this hydrogen sensor can include: using a laser to cut the hydrogen-permeable ceramic with gas selectivity into a predetermined size, for example, cutting it into a size of 3.2 mm * 2.5 mm; performing ceramic chip packaging on the tin dioxide-based semiconductor device, and using the hydrogen-permeable ceramic with a predetermined size as the cover plate for the ceramic chip packaging of the above-mentioned tin dioxide-based semiconductor device to obtain a hydrogen sensor. The method for preparing the hydrogen sensor will be described below through examples and comparative examples.
[0048] Example
[0049] Step 1: Weigh 20 g to 30 g of alumina, 0.75 g to 1.25 g of magnesia, 0.15 g to 0.3 g of iron oxide, 3 g to 5 g of zinc oxide, 3 g to 5 g of corn starch, 0.2 g to 0.5 g of methyl cellulose, measure 2 mL to 3 mL of PEG600, 2 mL to 3 mL of glycerol and 100 mL to 150 mL of water into a 500 mL ball milling jar.
[0050] Step 2: Continuously ball mill the mixture in Step 1 at 300 rpm for 24 h.
[0051] Step 3: Place the slurry obtained in Step 2 in an oven at 80 °C and dry it for 24 h.
[0052] Step 4: Screen the ceramic powder obtained in Step 3 through a 100-mesh sieve to obtain ceramic powder with a particle size of 100 mesh.
[0053] Step 5: Weigh an appropriate amount of the powder obtained in Step 4 and press it into shape through a powder press to obtain a green ceramic body.
[0054] Step 6: Sinter the green ceramic body obtained in Step 5 through a high-temperature program. In an air atmosphere, raise the temperature at a rate of 1 °C / min to 2 °C / min to 500 °C, and keep it at 500 °C for 1 h; then raise the temperature at a rate of 1 °C / min to 2 °C / min to 1500 °C to 1600 °C, and keep it at 1500 °C to 1600 °C for 1 h to 3 h; subsequently, lower the temperature at a rate of 1 - 2 °C / min to room temperature to obtain a breathable ceramic sheet.
[0055] Step 7: Uniformly mix hydrogen-containing hydrogen silicone oil and ethyl acetate according to a mass ratio of 6:4 to 9:1.
[0056] Step 8: Immerse the ceramic sheet obtained in Step 6 into the mixed solution in Step 7, soak it for 5 min to 10 min, take it out and dry it at 80 °C for 20 min.
[0057] Step 9: Repeat the operation in Step 8 1 to 5 times.
[0058] Step 10: Place the dried breathable ceramic sheet obtained in Step 9 into a high-temperature sintering furnace. In an air atmosphere, raise the temperature at a rate of 2 °C / min to 5 °C / min to 500 °C, keep it at 500 °C for 2 h, and then naturally lower the temperature to room temperature.
[0059] Step 11: Perform the operations in Step 8 to Step 10 on the ceramic sheet in Step 10 again, repeat 1 to 3 times to obtain a hydrogen-permeable ceramic sheet with gas selectivity;
[0060] Step 12: Use a laser to cut the hydrogen-permeable ceramic sheet with gas selectivity into 3.2 mm * 2.5 mm;
[0061] Step 13: Select a tin dioxide-based semiconductor chip and perform 3225 ceramic chip packaging. The cover plate uses the 3.2 mm * 2.5 mm hydrogen-permeable ceramic sheet with gas selectivity in Step 12.
[0062] Comparative Example
[0063] Step 1: Weigh 20 g to 30 g of alumina, 0.75 g to 1.25 g of magnesia, 0.15 g to 0.3 g of iron oxide, 3 g to 5 g of zinc oxide, 3 g to 5 g of corn starch, 0.2 g to 0.5 g of methyl cellulose, measure 2 mL to 3 mL of PEG600, 2 mL to 3 mL of glycerol, and 100 mL to 150 mL of water into a 500 mL ball mill jar.
[0064] Step 2: Continuously ball mill the slurry in Step 1 at 300 rpm for 24 h.
[0065] Step 3: Place the slurry obtained in Step 2 in an oven at 80 °C and bake for 24 h.
[0066] Step 4: Screen the ceramic powder obtained in Step 3 through a 100-mesh sieve to obtain ceramic powder with a particle size of 100 mesh.
[0067] Step 5: Weigh an appropriate amount of the powder obtained in Step 4 and press it into shape through a powder press to obtain a green ceramic body.
[0068] Step 6: Sinter the green ceramic body obtained in Step 5 through a high-temperature program. In an air atmosphere, increase the temperature at a rate of 1 °C / min to 2 °C / min to 500 °C and hold for 1 h at 500 °C; then increase the temperature at a rate of 1 °C / min to 2 °C / min to 1500 °C to 1600 °C and hold for 1 h to 3 h at 1500 °C to 1600 °C; subsequently, decrease the temperature at a rate of 1 - 2 °C / min to room temperature to obtain a hydrogen-permeable ceramic sheet.
[0069] Step 7: Cut the hydrogen-permeable ceramic sheet in Step 6 into 3.2 mm * 2.5 mm using a laser;
[0070] Step 8: Select a tin dioxide-based semiconductor chip and perform 3225 ceramic chip packaging. The cover plate uses the 3.2 mm * 2.5 mm hydrogen-permeable ceramic sheet in Step 7.
[0071] By performing performance tests on the hydrogen sensors prepared in the examples and the hydrogen sensors prepared in the comparative examples, the test comparisons obtained can be as Figures 3 to 7 shown.
[0072] Figure 3 Schematically shows the response curves of the hydrogen-permeable ceramic with gas selectivity in the hydrogen sensor of the embodiment of the present disclosure and the hydrogen-permeable ceramic in the hydrogen sensor of the test example to hydrogen.
[0073] As Figure 3 shown, the abscissa is time and the ordinate is resistance. Figure 3 10 ppm, 50 ppm, 200 ppm, 500 ppm, and 2000 ppm in are all the concentrations of hydrogen gas introduced. Both the breathable ceramic and the hydrogen-permeable ceramic with gas selectivity have a high response to hydrogen gas, and there is no obvious difference in the response degree. It shows that using the hydrogen-permeable ceramic with gas selectivity as the cover plate of the hydrogen sensor can allow hydrogen gas to pass through, realizing real-time monitoring of hydrogen gas during the thermal runaway of lithium batteries.
[0074] Figure 4 Schematically shows the response curves of the hydrogen-permeable ceramic with gas selectivity in the hydrogen sensor of the embodiment of the present disclosure and the breathable ceramic in the hydrogen sensor of the test example to DMC; Figure 5 Schematically shows the response curves of the hydrogen-permeable ceramic with gas selectivity in the hydrogen sensor of the embodiment of the present disclosure and the breathable ceramic in the hydrogen sensor of the test example to EMC.
[0075] In the lithium battery pack, in addition to the combustible gases released by the thermal runaway of lithium electricity, there are also other interfering gases, such as the electrolyte vapor generated by electrolyte leakage. These gases will interfere with the semiconductor sensor and are prone to false alarms. Figure 4 and Figure 5 Show the response curves of the breathable ceramic and the hydrogen-permeable ceramic with gas selectivity to the vapor of dimethyl carbonate (DMC) and ethylene methyl carbonate (EMC) of the electrolyte of the gas sensor. Figure 4 50 ppm, 100 ppm, 200 ppm, 500 ppm, and 1000 ppm in are all the concentrations of DMC vapor introduced. Figure 5 50 ppm, 100 ppm, 200 ppm, 500 ppm, and 1000 ppm in are all the concentrations of EMC vapor introduced. As Figure 4 and Figure 5 shown, the breathable ceramic has a response characteristic to both DMC and EMC vapors, while the hydrogen-permeable ceramic with gas selectivity does not show an obvious response characteristic to DMC and EMC vapors. It shows that using the hydrogen-permeable ceramic with gas selectivity as the cover plate can effectively prevent the infiltration of electrolyte vapor, avoid the interference of electrolyte vapor to the sensor, and thus improve the detection efficiency of the sensor.
[0076] Figure 6 Schematically shows the response curves of the hydrogen-permeable ceramic with gas selectivity in the hydrogen sensor of the embodiment of the present disclosure and the breathable ceramic in the hydrogen sensor of the test example to the gas of silicone sealant.
[0077] In addition to the electrolyte vapor generated by electrolyte leakage, the gas released by the silicone sealant will also cause great interference to the semiconductor sensor.Figure 6 The graph shows the response curves of the gas permeable ceramic and the gas-selective hydrogen permeable ceramic to the gas of the silicone sealant when 2.2g of the silicone sealant is squeezed into a 5L cavity and allowed to volatilize freely. Figure 6 As shown in the figure, within the sealing response time of 30 minutes, the breathable ceramic has an obvious response to the organic silicone gas, and the gas-selective hydrogen-permeable ceramic only produces a slight change, indicating that the gas-selective hydrogen-permeable ceramic as a cover can effectively prevent the penetration of organic silicone sealant gas and avoid the interference of organic silicone sealant gas on the sensor, thereby improving the detection efficiency of the sensor.
[0078] Figure 7 The response curves of the gas-selective hydrogen permeable ceramic in the hydrogen sensor of the embodiment of the present disclosure and the gas-permeable ceramic in the hydrogen sensor of the test example to CO gas are schematically shown.
[0079] When a lithium battery goes into thermal runaway, it will release a large amount of flammable gas, including carbon monoxide gas in addition to hydrogen. Figure 7 The response curves of gas-permeable ceramics and gas-selective hydrogen-permeable ceramics to carbon monoxide gas are shown respectively. Figure 7 The 10ppm and 100ppm in the figure are the concentrations of the CO gas introduced. Figure 7 As shown, the air-permeable ceramic has a response characteristic to carbon monoxide gas, while the gas-selective hydrogen-permeable ceramic has no obvious response characteristic to carbon monoxide, indicating that the gas-selective hydrogen-permeable ceramic as a cover plate can effectively prevent the infiltration of carbon monoxide gas.
[0080] According to the embodiments of the present disclosure, hydrogen-permeable ceramics are impregnated and sintered with hydrogen-containing silicone oil to obtain gas-selective hydrogen-permeable ceramics that can effectively permeate hydrogen and prevent the penetration of other gases. A hydrogen gas sensor that uses the gas-selective hydrogen-permeable ceramics as a cover plate for packaging can have high selectivity for hydrogen, and can eliminate the influence of common electrolyte (DMC, EMC, etc.) leakage in the battery pack, silicone sealant, and gases such as CO during thermal runaway, thereby achieving high selectivity for H2.
[0081] It should be noted that, unless it is explicitly stated that there is a sequence of execution between different steps in the flowchart in the embodiments of the present invention, or there is a sequence of execution between different steps in technical implementation, otherwise, the execution order between multiple steps may not be particular, and multiple steps may also be executed simultaneously.
[0082] Those skilled in the art will understand that the features described in the various embodiments of the present disclosure can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the features described in the various embodiments of the present disclosure can be combined and / or combined in various ways. All such combinations and / or combinations fall within the scope of the present disclosure.
[0083] The embodiments of the present disclosure have been described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments have been described separately above, this does not mean that the measures in the respective embodiments cannot be used advantageously in combination. Without departing from the scope of the present disclosure, those skilled in the art can make various substitutions and modifications, and all such substitutions and modifications should fall within the scope of the present disclosure.
Claims
1. A method for preparing a hydrogen-permeable ceramic with gas selectivity, characterized in that, The method includes: Put alumina, magnesia, iron oxide, zinc oxide, corn starch, methyl cellulose, polyethylene glycol, glycerol and water into a ball milling device for ball milling to obtain a ceramic slurry; Dry and screen the ceramic slurry and then press it into a green ceramic body, and sinter the green ceramic body to obtain a breathable ceramic; Perform the following steps on the breathable ceramic in a cycle until the number of sintering times reaches a first predetermined number: First, immerse the breathable ceramic in a mixed solution of hydrogen-containing silicone oil and ethyl acetate, and then dry the breathable ceramic taken out from the mixed solution to obtain a dried breathable ceramic, wherein the process of first immersing the breathable ceramic and then drying the breathable ceramic needs to be cycled a second predetermined number of times; Sinter the dried breathable ceramic to obtain a sintered ceramic sheet; Use the sintered ceramic sheet with the first predetermined number of times as a hydrogen-permeable ceramic with gas selectivity.
2. The method according to claim 1, wherein The first predetermined number includes 1 to 3 times; the second predetermined number includes 1 to 5 times.
3. The method according to claim 1, wherein The step of first immersing the breathable ceramic in a mixed solution of hydrogen-containing silicone oil and ethyl acetate and then drying the breathable ceramic taken out from the mixed solution includes: Immerse the breathable ceramic in the mixed solution for 5 to 10 minutes, and then dry the breathable ceramic taken out from the mixed solution at 80 °C for a first predetermined duration.
4. The method according to claim 3, characterized in that, The mass ratio of the hydrogen-containing silicone oil to the ethyl acetate in the mixed solution includes 6:4 to 9:
1.
5. The method according to claim 1, wherein Sintering the dried breathable ceramic includes: Raise the temperature to 500 °C at a heating rate of 2 °C / min to 5 °C / min in an air atmosphere, and keep it at 500 °C for a second predetermined duration, and then naturally cool it to a predetermined temperature.
6. The method according to claim 5, wherein The step of sintering the green ceramic body to obtain a breathable ceramic includes: Raise the temperature of the green ceramic body to 500 °C at a heating rate of 1 °C / min to 2 °C / min in an air atmosphere, and keep it at 500 °C for a third predetermined duration; then raise the temperature to 1500 °C to 1600 °C at a heating rate of 1 °C / min to 2 °C / min, and keep it at 1500 °C to 1600 °C for 1 to 3 hours; then cool it to the predetermined temperature at a cooling rate of 1 °C / min to 2 °C / min to obtain the breathable ceramic.
7. The method according to claim 1, characterized in that, The mass of the alumina includes 20 g to 30 g; the mass of the magnesia includes 0.75 g to 1.25 g; the mass of the iron oxide includes 0.15 g to 0.3 g; the mass of the zinc oxide includes 3 g to 5 g; the mass of the corn starch includes 3 g to 5 g; the mass of the methyl cellulose includes 0.2 g to 0.5 g; the volume of the polyethylene glycol includes 2 mL to 3 mL; the volume of the glycerol includes 2 mL to 3 mL; and the volume of the water includes 100 mL to 150 mL.
8. A hydrogen-permeable ceramic with gas selectivity, characterized in that, Prepared by using the preparation method of the hydrogen-permeable ceramic with gas selectivity as described in any one of claims 1 to 7.
9. A hydrogen sensor, characterized in that, It includes a cover plate, a ceramic base, gold wires and a tin dioxide-based semiconductor device, wherein the material of the cover plate includes the hydrogen-permeable ceramic with gas selectivity as described in claim 8.
10. A method for preparing a hydrogen sensor, characterized in that, The method includes: Cut a hydrogen-permeable ceramic with gas selectivity into a predetermined size using a laser, wherein the hydrogen-permeable ceramic with gas selectivity is prepared according to the preparation method of the hydrogen-permeable ceramic with gas selectivity as described in any one of claims 1 to 7; Perform ceramic chip packaging on a tin dioxide-based semiconductor device, and use a hydrogen-permeable ceramic with gas selectivity of a predetermined size as the cover plate for the ceramic chip packaging of the tin dioxide-based semiconductor device to obtain a hydrogen sensor.