Composite gradient graphene electric kettle and preparation method thereof

Abstract

The composite gradient graphene electric kettle comprises a kettle body, a kettle cover and a charging base, the bottom of the kettle body is connected with a kettle base, a charging socket is arranged in the kettle base and electrically connected with the charging base, and the composite gradient graphene electric kettle further comprises a composite gradient electric heating ceramic substrate fixed to the inner bottom of the kettle body in a sealed mode. The composite gradient electric heating ceramic substrate structurally comprises a surface layer and a surface layer, wherein the surface layer comprises an AlN-rich layer with the thickness of 50-100 microns and a transition layer containing 5-8 vol% of amorphous carbon; the middle layer is a SiC-AlN gradient transition area, and the AlN content is decreased by 10 vol% per 100 [mu] m thickness; the core heating layer is a molybdenum-doped SiC layer with the thickness of 500-800 [mu] m, the doping concentration is 0.3-0.8 at%, and a micropore array with the periodic aperture of 10-50 [mu] m and the porosity of 3-5% is contained in the molybdenum-doped SiC layer; baTiO3 coated SiO2 core-shell nanoparticles (0.5-1 vol%) are dispersed in the core heating layer, and the thickness of the SiO2 shell layer is 5-10 nm; the bottom of the composite gradient electric heating ceramic substrate is coated with a graphene heating coating, and a flexible phase change energy storage material film is attached to the lower portion of the graphene heating coating.

Description

Technical Field

[0001] The present invention relates to the technical field of electric heating appliances, and in particular to a high-performance electric kettle based on composite gradient electrothermal ceramic and graphene heating technology and a preparation method thereof. Background Art

[0002] Traditional electric kettles generally use metal heating wires (such as nickel-chromium alloys) or glass-ceramic heating films as heating elements. Metal heating wires suffer from low resistivity (heating efficiency <92%), high thermal inertia, and susceptibility to oxidation at high temperatures. While glass-ceramic heating films offer the advantage of transparency, they have a thermal conductivity of only 2-5 W / m·K, a maximum operating temperature of ≤350°C, and poor thermal shock stability (ΔT <250°C). This results in low heating efficiency (approximately 78%) and insufficient thermal insulation.

[0003] Recent graphene electric kettles (e.g., CN116869355A) improve heating efficiency by coating the bottom surface of a glass-ceramic plate with a graphene heating layer. However, these improvements are still limited by the low thermal conductivity of the glass-ceramic substrate and lack a high-temperature protection mechanism. Meanwhile, composite gradient electrothermal materials developed in the specialty ceramics field (e.g., Patent Document 1) exhibit high-temperature stability up to 1600°C, high thermal conductivity of 135W / m·K, and thermal shock resistance up to 880°C, but have yet to be applied to liquid heating appliances. Utility Model Content

[0004] The present invention addresses the three major defects of existing electric kettles, namely low heating efficiency, poor high-temperature stability, and insufficient thermal insulation performance. By integrating composite gradient electrothermal ceramic technology with a graphene heating solution, the present invention provides an efficient, long-life, intelligent electric kettle and a preparation method thereof.

[0005] In order to solve the above technical problems, the present invention provides a composite gradient graphene electric kettle and a preparation method thereof to solve the above technical defects.

[0006] In order to solve one of the above technical problems, the technical solution adopted is as follows:

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

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

[0009] Intermediate layer: SiC-AlN gradient transition zone, AlN content decreases by 10 vol% every 100 μm thickness;

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

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

[0012] In order to better achieve the purpose of the invention, the present invention also has the following better solutions:

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

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

[0015] Doped phase: 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), 0.5-1 vol% CeO2-Y2O3 (molar ratio 1:1) grain boundary nanoparticles.

[0016] In some embodiments, the microwell array is formed by laser selective ablation at a wavelength of 1064 nm and a power density of 10 6 -10 7 W / cm 2 The amorphous carbon transition layer is in-situ generated by CVD at 800-1000°C using 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 rubber ring is provided between the kettle body and the kettle lid, wherein an annular protrusion and a conical protrusion extending into the spout are provided on the outer periphery of the rubber ring; an elastic metal plate and a sealing plate are provided inside the kettle lid, both surfaces of which are coated with a thermal insulation coating, and a circular hole is provided on the elastic metal plate for steam to pass through.

[0018] In some specific embodiments, the kettle handle has a built-in water quality monitor, which is connected to the bottom of the kettle body through water inlet hole 1 and water inlet hole 2; a battery and a display are provided in the kettle handle, and the battery is connected to the water quality monitor via a magnetic charging connector.

[0019] Another object of the present invention is to provide a method for preparing the 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 substrates: SiC, AlN, La-ZrO2, CeO2-Y2O3, h-BN-modified graphene, and ammonium molybdate were ball-milled and mixed; the powders were activated using microwave-assisted plasma (2.45 GHz, 500-800 W, 10 min); a gradient mold was filled with 20-50 μm graphene-h-BN composite paper between layers; SPS pre-sintering was performed at 1700-1900°C and 50-80 MPa for 5 min; laser cladding was performed using AlN-SiC mixed powder (proportionally matched gradient layers), 3-5 kW coaxial powder feeding, and a scanning speed of 10-20 mm / s.

[0021] (b) Substrate post-processing: CVD deposition of an amorphous carbon layer (900°C, CH4 / Ar mixture); laser ablation to form a micropore array; and surface coating with a SiO2-Al2O3 anti-oxidation coating.

[0022] (c) Component integration: Coat the bottom of the substrate with a graphene heating coating and adhere it to the flexible phase change energy storage material membrane; seal the substrate to the kettle body; assemble the water quality monitor, battery, and display.

[0023] In some specific embodiments, in the laser cladding process of step (a), the porosity of the cladding layer is controlled to be less than 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 electric heating efficiency reaches 96.8% (compared to 78% for traditional glass-ceramic kettles), and the water boils in 10 seconds. The graphene coating + gradient ceramic substrate increases the heating efficiency by more than 40%.

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

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

[0028] 3) Intelligent Internet of Things: The water quality monitor (18) can display TDS and biological residue in real time; the battery (12) can support 72 hours of off-grid monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[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 pot lid;

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

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

[0033] Figure 5 : Process flow chart of composite gradient ceramic substrate. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below with reference to the embodiments, which are limited to provide a clearer understanding of the technical features, purposes and effects of the present invention.

[0035] Refer to the attached Figure 1-5 As shown, the present application provides a composite gradient graphene electric kettle, comprising 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. The kettle base 1 has a built-in charging socket 11 electrically connected to the charging base 5. The kettle body 2 also includes a composite gradient electrothermal ceramic substrate 7 sealed and fixed to the bottom of the kettle body. The structure of the composite gradient electrothermal ceramic substrate 7 includes:

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

[0037] Intermediate layer: SiC-AlN gradient transition zone, AlN content decreases by 10 vol% every 100 μm thickness;

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

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

[0040] In order to better achieve the purpose of the invention, the present invention also has the following better solutions:

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

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

[0043] Doped phase: 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), 0.5-1 vol% CeO2-Y2O3 (molar ratio 1:1) grain boundary nanoparticles.

[0044] In some embodiments, the microwell array is formed by laser selective ablation at a wavelength of 1064 nm and a power density of 10 6 -10 7 W / cm 2 The amorphous carbon transition layer is in-situ generated by CVD at 800-1000°C using 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 rubber ring 17 is provided between the kettle body 2 and the kettle lid 4, wherein an annular protrusion and a conical protrusion extending into the spout 21 are provided on the outer periphery of the rubber ring; an elastic metal plate 14 and a sealing plate 15 are provided inside the kettle lid 4, both surfaces of which are coated with a thermal insulation coating 16, and a circular hole 141 is provided on the elastic metal plate 14 for steam to pass through.

[0046] In some specific embodiments, the kettle handle 3 has a built-in water quality monitor 18, which is connected to the bottom of the kettle body 2 through water inlet hole 1 22 and water inlet hole 2 23; the kettle 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 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 substrates: SiC, AlN, La-ZrO2, CeO2-Y2O3, h-BN-modified graphene, and ammonium molybdate were ball-milled and mixed; the powders were activated using microwave-assisted plasma (2.45 GHz, 500-800 W, 10 min); a gradient mold was filled with 20-50 μm graphene-h-BN composite paper between layers; SPS pre-sintering was performed at 1700-1900°C and 50-80 MPa for 5 min; laser cladding was performed using AlN-SiC mixed powder (proportionally matched gradient layers), 3-5 kW coaxial powder feeding, and a scanning speed of 10-20 mm / s.

[0049] (b) Substrate post-processing: CVD deposition of an amorphous carbon layer (900°C, CH4 / Ar mixture); laser ablation to form a micropore array; and surface coating with a SiO2-Al2O3 anti-oxidation coating.

[0050] (c) Component integration: Coat the bottom of the substrate with a graphene heating coating and adhere it to the flexible phase change energy storage material membrane; seal the substrate to the kettle body; assemble the water quality monitor, battery, and display.

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

[0052] Key steps of the preparation method:

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

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

[0055] Composite sintering: SPS pre-sintering: 1850℃ / 60MPa / 5 minutes to form a green body; laser cladding: 4kW power, 15mm / s scanning speed to deposit 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 of a SiO2-Al2O3 coating (15μm).

[0056] The whole machine is assembled: a graphene heating coating (6) is screen-printed on the back of a substrate (7), and a paraffin wax / graphene composite phase change film (8) is laminated by hot pressing; the edge of the substrate (7) is sealed with the bottom of the kettle body (2); and a water quality monitor (18) and a magnetic charging connector (121) are integrated.

[0057] Among them, gradient ceramic substrate:

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

[0059] Machine assembly:

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

[0061] Performance comparison test

[0062] project Kettle of the present invention Traditional glass-ceramic pot Commercial SiC heating pot Heating to boiling time 210s 365s 280s 100℃ insulation time 4.2h 1.3h 2.1h 1500 hot and cold cycles No cracks 200th rupture 800th micro-crack Thermal efficiency (100℃) 96.5％ 78.2％ 88.7％

[0063] Extreme environment testing

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

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

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

[0067] The kettle of this invention is suitable for use in household applications, medical sterilization, and laboratories. The gradient ceramic substrate can be expanded 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 examples are merely preferred embodiments of the present invention, and all technical solutions defined in the claims are intended to fall within the scope of protection of this invention.

Claims

1. A composite gradient graphene electric kettle, comprising a kettle body (2), a kettle lid (4) and a charging stand (5), wherein the bottom of the kettle body (2) is connected to the kettle stand (1), and the kettle stand (1) has a built-in charging socket (11) electrically connected to the charging stand (5), characterized in that: The kettle body (2) further comprises a composite gradient electrothermal ceramic substrate (7) sealed and fixed to the inner bottom of the kettle body (2). The structure of the composite gradient electrothermal ceramic substrate (7) comprises: Surface layer: 50-100 μm thick AlN-rich layer, containing 5-8 vol% amorphous carbon transition layer; Intermediate layer: SiC-AlN gradient transition zone, AlN content decreases by 10 vol% every 100 μm thickness; Core heating layer: Mo-doped SiC layer with a thickness of 500-800 μm, a doping concentration of 0.3-0.8 at%, and a micropore array with a periodic pore size of 10-50 μm and a porosity of 3-5%; BaTiO3@SiO2 core-shell nanoparticles (0.5-1 vol%) are dispersed in the core heating layer, and the SiO2 shell thickness is 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: 60-70vol% SiC and 20-30vol% AlN composite ceramics; Doped phase: 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), 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 microhole array is formed by laser selective ablation at a wavelength of 1064 nm and a power density of 10 6 -10 7 W / cm 2 The amorphous carbon transition layer is in-situ generated by CVD at 800-1000°C using a CH4:Ar=1:9 mixed gas; the surface of the substrate (7) is coated with a 10-20 μm thick SiO2-Al2O3 composite anti-oxidation 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 lid (4), and an annular protrusion and a conical protrusion extending into the kettle spout (21) are provided on the outer periphery of the sealing rubber ring (17); an elastic metal plate (14) and a blocking plate (15) are provided inside the kettle lid (4), and both surfaces are coated with a heat-insulating coating (16); and a circular hole (141) is provided on the elastic metal plate (14) for steam to pass through.

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

6. The method for preparing an electric kettle according to any one of claims 1 to 5, characterized in that The following steps are involved: (a) Preparation of composite gradient ceramic substrates: SiC, AlN, La-ZrO2, CeO2-Y2O3, h-BN-modified graphene, and ammonium molybdate were ball-milled and mixed; the powders were activated using microwave-assisted plasma (2.45 GHz, 500-800 W, 10 min); a gradient mold was filled with 20-50 μm graphene-h-BN composite paper between layers; SPS pre-sintering was performed at 1700-1900°C and 50-80 MPa for 5 min; laser cladding was performed using AlN-SiC mixed powder (proportionally matched gradient layers), 3-5 kW coaxial powder feeding, and a scanning speed of 10-20 mm / s. (b) Substrate post-processing: CVD deposition of an amorphous carbon layer (900°C, CH4 / Ar mixture); laser ablation to form a micropore array; and surface coating with a SiO2-Al2O3 anti-oxidation coating. (c) Component integration: coating the bottom of the substrate (7) with a graphene heating coating (6) and laminating the flexible phase change energy storage material film (8); sealingly connecting the substrate (7) to the kettle body (2); and assembling the water quality monitor (18), battery (12) and display (10).

7. The preparation method according to claim 6, characterized in that: 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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