Composite gradient graphene electric kettle and preparation method thereof

Abstract

The application discloses a composite gradient graphene electric kettle and a preparation method thereof. The electric kettle comprises a kettle body, a kettle cover and a charging seat. The bottom of the kettle body is connected with a kettle seat. The kettle seat is internally provided with a charging socket which is electrically connected with the charging seat. The electric kettle further comprises a composite gradient electric heating ceramic substrate which is sealingly fixed to the bottom of the kettle body. The structure of the composite gradient electric heating ceramic substrate comprises: a surface layer, an AlN-rich layer with a thickness of 50-100 microns and containing a 5-8 vol% amorphous carbon transition layer; a middle layer, a SiC-AlN gradient transition zone with the AlN content decreasing by 10 vol% per 100 microns of thickness; a core heating layer, a molybdenum-doped SiC layer with a thickness of 500-800 microns, a doping concentration of 0.3-0.8 at%, and a micropore array with a periodic pore diameter of 10-50 microns and a porosity of 3-5%; the core heating layer is dispersed with BaTiO3@SiO2 core-shell nanoparticles (0.5-1 vol%), and the SiO2 shell layer has a thickness of 5-10 nm; a graphene heating coating is coated on the bottom of the composite gradient electric heating ceramic substrate, and a flexible phase change energy storage material film is attached below the graphene heating coating.

Description

Technical Field

[0001] This invention relates to the field of electric heating appliances, and in particular to a high-performance electric kettle based on composite gradient electrothermal ceramics and graphene heating technology, and its preparation method. Background Technology

[0002] Traditional electric kettles generally use metal heating wires (such as nickel-chromium alloys) or microcrystalline glass heating films as heating elements. Metal heating wires have problems such as low resistivity (thermal efficiency <92%), high thermal inertia, and easy oxidation at high temperatures; although microcrystalline glass heating films have the advantage of transparency, their thermal conductivity is only 2-5 W / m·K, the maximum operating temperature is ≤350℃, and their thermal shock stability is poor (ΔT<250℃), resulting in low heating efficiency (about 78%) and insufficient heat preservation performance.

[0003] Graphene electric kettles that have emerged in recent years (such as CN116869355A) improve heating efficiency by coating a graphene heating layer on the bottom surface of a microcrystalline glass substrate, but they are still limited by the low thermal conductivity of the microcrystalline glass substrate and lack a high-temperature protection mechanism. On the other hand, composite gradient electrothermal materials developed in the field of special ceramics (such as patent document 1) have high-temperature stability of 1600℃, high thermal conductivity of 135W / m·K and thermal shock resistance of 880℃, but they have not yet been applied to liquid heating appliances. Utility Model Content

[0004] This invention addresses the three major shortcomings of existing electric kettles: low heating efficiency, poor high-temperature stability, and insufficient heat preservation performance. By integrating composite gradient electrothermal ceramic technology with a graphene heating scheme, it provides a high-efficiency, long-life, and intelligent electric kettle and its preparation method.

[0005] To address the aforementioned technical problems, this invention provides a composite gradient graphene electric kettle and its preparation method, thereby resolving the aforementioned technical deficiencies.

[0006] To solve one of the aforementioned technical problems, the following technical solution is adopted:

[0007] This application provides a composite gradient graphene electric kettle, including a kettle body, a kettle lid, and a charging base. The kettle body is connected to the kettle base at the bottom, and the kettle base has a built-in charging socket electrically connected to the charging base. The kettle also includes a composite gradient electrothermal ceramic substrate sealed and fixed inside the bottom of the kettle body. The structure of the composite gradient electrothermal ceramic substrate includes:

[0008] Surface layer: AlN-rich layer with a thickness of 50-100μm, containing 5-8 vol% amorphous carbon transition layer;

[0009] Intermediate layer: SiC-AlN gradient transition region, with AlN content decreasing by 10 vol% per 100 μm thickness;

[0010] Core heating layer: a molybdenum-doped SiC layer with a thickness of 500-800 μm and a doping concentration of 0.3-0.8 at%, containing a periodic array of micropores with a pore size of 10-50 μm and a porosity of 3-5%; BaTiO3@SiO2 core-shell nanoparticles (0.5-1 vol%) are dispersed within the core heating layer, with a SiO2 shell thickness of 5-10 nm;

[0011] A graphene heating coating is coated on the bottom of a composite gradient electrothermal ceramic substrate, and a flexible phase change energy storage material membrane is attached below the graphene heating coating.

[0012] To better achieve the purpose of the invention, the present invention also has the following preferred solutions:

[0013] In some specific embodiments, the composite gradient electrothermal ceramic substrate is composed of the following components:

[0014] Matrix: 60-70 vol% SiC and 20-30 vol% AlN composite ceramic;

[0015] Doped phases: 3-5 vol% La-stabilized ZrO2 (La content 0.1-0.5 wt%), 1-2 vol% h-BN-coated graphene nanosheets (coating layer <2 nm), and 0.5-1 vol% CeO2-Y2O3 (molar ratio 1:1) grain boundary nanoparticles.

[0016] In some specific embodiments, the micropore array is formed by selective ablation with a wavelength of 1064 nm and a power density of 10. 6 -10 7 W / cm 2 The amorphous carbon transition layer is generated in situ at 800-1000℃ by CVD of a CH4:Ar = 1:9 mixed gas; the substrate surface is coated with a 10-20μm thick SiO2-Al2O3 composite anti-oxidation coating.

[0017] In some specific embodiments, a sealing ring is provided between the kettle body and the kettle lid, wherein the outer periphery of the sealing ring is provided with an annular protrusion and a conical protrusion extending into the spout; the kettle lid is provided with an elastic metal plate and a sealing plate, both of which are coated with a heat-insulating coating, and the elastic metal plate has a round hole for steam to pass through.

[0018] In some specific embodiments, the handle has a built-in water quality monitor, which is connected to the bottom of the kettle body through water inlet one and water inlet two; the handle also has a battery and a display, and the battery is connected to the water quality monitor through a magnetic charging connector.

[0019] Another object of the present invention is to provide a method for preparing the above-mentioned composite gradient graphene electric kettle: the method for preparing the electric kettle is characterized by comprising the following steps:

[0020] (a) Preparation of composite gradient ceramic substrate: SiC, AlN, La-ZrO2, CeO2-Y2O3, h-BN modified graphene and ammonium molybdate are ball-milled and mixed; the powder is activated by microwave-assisted plasma (2.45GHz, power 500-800W, 10 minutes); gradient filling mold is used, and 20-50μm graphene-h-BN composite paper is laid between the layers; SPS pre-sintering: 1700-1900℃, 50-80MPa for 5 minutes; laser cladding: AlN-SiC mixed powder (proportionally matched gradient layer) is used, 3-5kW coaxial powder feeding, scanning speed 10-20mm / s;

[0021] (b) Substrate post-treatment: CVD deposition of amorphous carbon layer (900℃, CH4 / Ar mixed gas); laser ablation to form micropore array; surface coating with SiO2-Al2O3 anti-oxidation coating;

[0022] (c) Component integration: The bottom of the substrate is coated with a graphene heating coating and a flexible phase change energy storage material membrane is attached; the substrate is sealed to the body of the kettle; and the water quality monitor, battery and display are assembled.

[0023] In some specific embodiments, in step (a) of the laser cladding process, the porosity of the cladding layer is controlled to be <0.5%.

[0024] Due to the adoption of the above technical solution, the beneficial effects of this application are as follows:

[0025] 1) Breakthrough in heating performance: The electrothermal efficiency reaches 96.8% (compared to 78% for traditional microcrystalline glass kettles), and it heats up to boiling in 10 seconds; the graphene coating and gradient ceramic substrate improve the heating efficiency by more than 40%.

[0026] 2) Extreme environmental stability: Operating temperature 1600℃, thermal shock resistance ΔT 880℃ (no cracking after water quenching); resistivity increases by only 1.5% after 1000 hours of vacuum aging at 1500℃ (compared to 12% for commercial SiC). Long-term heat preservation: Phase change energy storage membrane allows water temperature of 100℃ to be maintained for up to 4 hours (traditional kettles ≤ 1.5 hours);

[0027] The sealing ring (17) and the thermal insulation coating (16) work together to reduce heat loss by 30%.

[0028] 3) Smart IoT: The water quality monitor (18) displays TDS and biological residue in real time; the battery (12) supports 72 hours of off-grid monitoring. Attached Figure Description

[0029] Figure 1 : Schematic diagram of the overall cross-sectional structure of the kettle;

[0030] Figure 2 : Schematic diagram of the cross-sectional structure of the kettle lid;

[0031] Figure 3 : Figure 2 A magnified view of position A in the middle;

[0032] Figure 4 Schematic diagram of the charging dock structure;

[0033] Figure 5 Flowchart of composite gradient ceramic substrate process. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the embodiments. The embodiments are only intended to provide a clearer understanding of the technical features, objectives and effects of the present invention.

[0035] See attached document Figure 1-5 As shown, this application provides a composite gradient graphene electric kettle, including a kettle body 2, a kettle lid 4, and a charging base 5. The bottom of the kettle body 2 is connected to the kettle base 1, and the kettle base 1 has a built-in charging socket 11 that is electrically connected to the charging base 5. It also includes a composite gradient electrothermal ceramic substrate 7 sealed and fixed inside the bottom of the kettle body. The structure of the composite gradient electrothermal ceramic substrate 7 includes:

[0036] Surface layer: AlN-rich layer with a thickness of 50-100μm, containing 5-8 vol% amorphous carbon transition layer;

[0037] Intermediate layer: SiC-AlN gradient transition region, with AlN content decreasing by 10 vol% per 100 μm thickness;

[0038] Core heating layer: a molybdenum-doped SiC layer with a thickness of 500-800 μm and a doping concentration of 0.3-0.8 at%, containing a periodic array of micropores with a pore size of 10-50 μm and a porosity of 3-5%; BaTiO3@SiO2 core-shell nanoparticles (0.5-1 vol%) are dispersed within the core heating layer, with a SiO2 shell thickness of 5-10 nm;

[0039] A graphene heating coating 6 is coated on the bottom 7 of a composite gradient electrothermal ceramic substrate, and a flexible phase change energy storage material membrane 8 is attached below the graphene heating coating 6.

[0040] To better achieve the purpose of the invention, the present invention also has the following preferred solutions:

[0041] In some specific embodiments, the composite gradient electrothermal ceramic substrate 7 is composed of the following components:

[0042] Matrix: 60-70 vol% SiC and 20-30 vol% AlN composite ceramic;

[0043] Doped phases: 3-5 vol% La-stabilized ZrO2 (La content 0.1-0.5 wt%), 1-2 vol% h-BN-coated graphene nanosheets (coating layer <2 nm), and 0.5-1 vol% CeO2-Y2O3 (molar ratio 1:1) grain boundary nanoparticles.

[0044] In some specific embodiments, the micropore array is formed by selective ablation with a wavelength of 1064 nm and a power density of 10. 6 -10 7 W / cm 2 The amorphous carbon transition layer is generated in situ at 800-1000℃ by CVD of a CH4:Ar = 1:9 mixed gas; the substrate surface is coated with a 10-20μm thick SiO2-Al2O3 composite anti-oxidation coating.

[0045] In some specific embodiments, a sealing ring 17 is provided between the kettle body 2 and the kettle lid 4, wherein the outer periphery of the sealing ring is provided with an annular protrusion and a conical protrusion extending into the spout 21; the kettle lid 4 is provided with an elastic metal plate 14 and a sealing plate 15, both of which are coated with a heat-insulating coating 16, and the elastic metal plate 14 has a round hole 141 for steam to pass through.

[0046] In some specific embodiments, the handle 3 has a built-in water quality monitor 18, which is connected to the bottom of the body 2 through a water inlet 1 22 and a water inlet 23; the handle 3 has a battery 12 and a display 10, and the battery 10 is connected to the water quality monitor 18 through a magnetic charging connector 121.

[0047] Another object of the present invention is to provide a method for preparing the above-mentioned composite gradient graphene electric kettle: the method for preparing the electric kettle is characterized by comprising the following steps:

[0048] (a) Preparation of composite gradient ceramic substrate: SiC, AlN, La-ZrO2, CeO2-Y2O3, h-BN modified graphene and ammonium molybdate are ball-milled and mixed; the powder is activated by microwave-assisted plasma (2.45GHz, power 500-800W, 10 minutes); gradient filling mold is used, and 20-50μm graphene-h-BN composite paper is laid between the layers; SPS pre-sintering: 1700-1900℃, 50-80MPa for 5 minutes; laser cladding: AlN-SiC mixed powder (proportionally matched gradient layer) is used, 3-5kW coaxial powder feeding, scanning speed 10-20mm / s;

[0049] (b) Substrate post-treatment: CVD deposition of amorphous carbon layer (900℃, CH4 / Ar mixed gas); laser ablation to form micropore array; surface coating with SiO2-Al2O3 anti-oxidation coating;

[0050] (c) Component integration: The bottom of the substrate is coated with a graphene heating coating and a flexible phase change energy storage material membrane is attached; the substrate is sealed to the body of the kettle; and the water quality monitor, battery and display are assembled.

[0051] In some specific embodiments, in step (a) of the laser cladding process, the porosity of the cladding layer is controlled to be <0.5%.

[0052] Key steps in the preparation method:

[0053] Gradient ceramic substrate preparation: Powder pretreatment: SiC / AlN / La-ZrO2 / CeO2-Y2O3 / h-BN-graphene / ammonium molybdate ball milling followed by microwave plasma activation (700W, 10 minutes);

[0054] Gradient molding: Graphene-h-BN composite paper (30μm) is laid between layers in the mold, and powders with matching components are filled in layers;

[0055] Composite sintering: SPS pre-sintering: 1850℃ / 60MPa / 5min to form a green body; Laser cladding: 4kW power, 15mm / s scanning speed to deposit an AlN-SiC gradient layer (porosity <0.5%); Micropore processing: 1064nm laser ablation to form an array with a pore size of 30μm and a porosity of 4%; Surface treatment: CVD deposition of an amorphous carbon layer (900℃, CH4:Ar=1:9), spraying a SiO2-Al2O3 coating (15μm).

[0056] Assembly of the whole machine: the back of the substrate (7) is screen-printed with graphene heating coating (6), and the paraffin / graphene composite phase change film (8) is hot-pressed and bonded; the edge of the substrate (7) is fused to the bottom of the pot body (2); the water quality monitor (18) and the magnetic charging connector (121) are integrated.

[0057] Among them, gradient ceramic substrate:

[0058] Formulation: Core layer: 65 vol% SiC + 0.6 at% Mo + 1 vol% BaTiO3@SiO2; Intermediate layer: AlN 50% → 30% gradient; Surface layer: 80 vol% AlN + 5 vol% amorphous carbon; Doped phase: 3 vol% La-ZrO2 + 1.5 vol% h-BN-graphene + 0.8 vol% CeO2-Y2O3.

[0059] Complete machine assembly:

[0060] The back of the substrate is coated with graphene slurry (20 μm thick), and after curing, a paraffin / expanded graphite phase change film (0.5 mm thick) is hot-pressed onto it. The edge of the substrate is sealed to the glass body (2) with borate glass solder. A water quality monitor (18) and a lithium-ion battery (12) are assembled inside the handle (3).

[0061] Performance comparison test

[0062] project This invention kettle Traditional microcrystalline glass teapot Commercial SiC heating kettle Heating to boiling time 210s 365s 280s 100℃ heat preservation time 4.2h 1.3h 2.1h 1500 cycles of heating and cooling No cracks 200th rupture 800th microcrack Thermal efficiency (100℃) 96.5％ 78.2％ 88.7％

[0063] Extreme environment testing

[0064] Vacuum high-temperature aging: After 1000 hours at 1500℃ / 10-3Pa, the substrate mass loss rate was 0.02%, and the resistivity increased by 1.5%.

[0065] Corrosion test: Heating at 800℃ for 500 hours in a 10% H2S / N2 atmosphere, the surface corrosion rate is 0.008 mm / year (0.12 mm / year for commercial SiC substrates);

[0066] Ultra-fast thermal cycling: 1600℃→25℃ water quenching (completed within 1 second), thermal conductivity decay of <3% after 5000 cycles.

[0067] This invention relates to a kettle suitable for household, medical sterilization, and laboratory applications. The gradient ceramic substrate can be extended to heating appliances such as electric ovens and instant water dispensers. The phase change energy storage membrane and water quality monitoring module are independently marketable accessories, forming a derivative business model. The above embodiments are merely preferred embodiments of this invention, and all technical solutions defined in the claims should be within the protection scope of this invention.

Claims

1. A composite gradient graphene electric kettle, comprising a kettle body (2), a kettle cover (4) and a charging seat (5), the bottom of the kettle body (2) is connected with a kettle seat (1), the kettle seat (1) is internally provided with a charging socket (11) which is electrically connected with the charging seat (5), characterized in that, Also included is a composite gradient electrothermal ceramic substrate (7) sealed and fixed to the bottom of the kettle body (2), the structure of the composite gradient electrothermal ceramic substrate (7) comprises: Surface layer: AlN-rich layer with a thickness of 50-100 μm, containing 5-8 vol% amorphous carbon transition layer; Middle layer: SiC-AlN gradient transition zone, AlN content decreases by 10 vol% per 100 μm thickness; Core heating layer: Molybdenum-doped SiC layer with a thickness of 500-800 μm, doping concentration 0.3-0.8 at%, containing a periodic pore array with a pore size of 10-50 μm and a porosity of 3-5%; The core heating layer disperses BaTiO3@SiO2 core-shell nanoparticles (0.5-1 vol%), and the SiO2 shell layer has a thickness of 5-10 nm; A graphene heating coating (6) is coated on the bottom of the composite gradient electrothermal ceramic substrate (7), and a flexible phase change energy storage material film (8) is attached below the graphene heating coating (6).

2. The composite gradient graphene electric kettle according to claim 1, characterized in that: The composite gradient electrothermal ceramic substrate (7) is composed of the following components: Matrix: 60-70 vol% SiC and 20-30 vol% AlN composite ceramic; Doped phase: 3-5 vol% La-stabilized ZrO2 (La content 0.1-0.5 wt%), 1-2 vol% h-BN-coated graphene nanosheet (coating layer <2 nm), and 0.5-1 vol% CeO2-Y2O2 (molar ratio 1:1) grain boundary nanoparticles.

3. The composite gradient graphene electric kettle according to claim 1, characterized in that: The micropore array is formed by selective ablation of a 1064 nm wavelength laser with a power density of 10 6 -10 7 W / cm 2 The amorphous carbon transition layer is generated in situ by CVD at 800-1000°C from a CH4:Ar = 1:9 mixed gas; the substrate (7) is coated with a 10-20 μm thick SiO2-Al2O3 composite oxidation-resistant coating.

4. The composite gradient graphene electric kettle according to claim 1, characterized in that: A sealing rubber ring (17) is provided between the kettle body (2) and the kettle cover (4), and an annular protrusion and a conical protrusion extending into the spout (21) are provided on the outer periphery of the sealing rubber ring (17); the kettle cover (4) is provided with an elastic metal plate (14) and a blocking plate (15), and the surfaces of the two are coated with a heat preservation coating (16), and the elastic metal plate (14) is provided with a circular hole (141) for steam to pass through.

5. The composite gradient graphene electric kettle according to claim 1, characterized in that: A water quality monitor (18) is built into the kettle handle (3), which communicates with the bottom of the kettle body (2) through water inlet hole one (22) and water inlet hole two (23); a battery (12) and a display (10) are provided in the kettle handle (3), and the battery (12) is connected to the water quality monitor (18) through a magnetic charging connector (121).

6. The method of claim 1-5, wherein the electric kettle is prepared by The method comprises the following steps: (a) Composite gradient ceramic substrate preparation: SiC, AlN, La-ZrO2, CeO2-Y2O3, h-BN modified graphene and ammonium molybdate are ball milled and mixed; microwave assisted plasma is used to activate the powder (2.45 GHz, power 500-800 W, 10 minutes); gradient loading mold, 20-50 μm graphene-h-BN composite paper is laid between layers; SPS pre-sintering: 1700-1900 ℃, 50-80 MPa, holding for 5 minutes; laser cladding: AlN-SiC mixed powder (gradient layer proportion matching), 3-5 kW coaxial powder feeding, scanning speed 10-20 mm / s; (b) Substrate post-processing: CVD deposition of amorphous carbon layer (900 ℃, CH4 / Ar mixed gas); laser ablation to form a micropore array; surface coating of SiO2-Al2O3 oxidation-resistant coating; (c) Component integration: the bottom of the substrate (7) is coated with a graphene heating coating (6), and a flexible phase change energy storage material film (8) is attached; the substrate (7) is sealed and connected with the kettle body (2); the water quality monitor (18), the battery (12) and the display (10) are assembled.

7. The method of claim 6, wherein: In the laser cladding process of step (a), the porosity of the cladding layer is controlled to be less than 0.5%.

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