High-power ceramic heater based on new energy automobile and manufacturing method of high-power ceramic heater

Abstract

The invention discloses a high-power ceramic heater based on a new energy automobile and a manufacturing method of the high-power ceramic heater, and relates to the technical field of ceramic heater manufacturing. The invention comprises: a hollow tubular ceramic matrix; the temperature sensing layer, the first ceramic substrate, the heating layer, the second ceramic substrate, the first metal layer and the first electroplating alloy layer are sequentially attached to the outer side of the ceramic base body; the second metal layer and the second electroplating alloy layer are sequentially attached to the inner side of the ceramic base body. Through surface treatment of the novel heating slurry, the novel ceramic material, the metal layer and the electroplated alloy layer and innovative design of the integrated temperature sensing layer, the high-power ceramic heater is excellent in performance, service life, safety, temperature control and temperature impact resistance, and can cope with a harsh working environment; a more stable and efficient heating solution is provided; due to the innovative design, the ceramic heater is more reliable and durable under high-power, high-pressure and complex working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic heater manufacturing, and in particular to a high-power ceramic heater for new energy vehicles and a manufacturing method thereof. Background Art

[0002] The high-voltage liquid heater is a key component in the thermal management system of the power battery of new energy vehicles. The high-voltage liquid heater is configured in the thermal management system of the power battery of new energy vehicles to quickly preheat the battery to the optimal operating temperature in a low-temperature environment, prevent the battery capacity from attenuating and the charging efficiency from decreasing at low temperatures, and meet the heating needs of the cabin.

[0003] Figure 1 As shown; it is a common high-power ceramic heater. The high-power ceramic heater is the core heating element of the high-pressure liquid heater and directly determines the performance of the high-pressure liquid heater. The structure of the above-mentioned high-power ceramic heater specifically includes: a hollow tubular ceramic substrate, and a heating layer and a ceramic substrate sequentially attached to the outside of the ceramic substrate.

[0004] The ceramic substrate is the structural component of the high-power ceramic heater, which plays a supporting and force-bearing role. During the operation of the high-power ceramic heater, the coolant flows through the tube of the ceramic substrate and fully exchanges heat with the ceramic heater. This allows the coolant to be heated and quickly transferred to the battery system, thereby increasing the operating temperature of the battery.

[0005] The heating layer is formed by printing the heating slurry and drying it. When voltage is applied to the heating layer, it conducts electricity and generates heat, thus increasing the temperature of the ceramic heater. The ceramic substrate is used to carry the heating slurry so that the heating slurry can still form a flat and orderly pattern in a semi-fluid state.

[0006] For the above Figure 1 The inventors found in their long-term practical research that the high-power ceramic heater structure shown above may cause the following technical problems during use: (1) The heating performance of a high-power ceramic heater is directly determined by the resistance of the heating layer. During the use of the ceramic heater, as the temperature rises, the resistance increases (that is, there is a positive temperature coefficient). This will cause the power of the ceramic heater to decrease under the same voltage environment, affecting the heating performance and affecting its use.

[0007] (2) During the use of high-power ceramic heaters, due to the high power, fast heating speed and low thermal conductivity of ceramics, it is easy to cause uneven local temperature of the ceramic heater and generate thermal stress, causing the inner wall of the ceramic heater to crack, making the insulation resistance lower than the insulation requirement of 50MΩ, and the service life is short.

[0008] When a high-power ceramic heater is applied to a high-pressure liquid heater, since the heating temperature cannot be monitored in the high-power ceramic heater, dry burning of the ceramic heater will occur when the coolant in the high-pressure liquid heater is missing.

[0009] Therefore, how to solve the above technical problems is a technical problem faced by those of ordinary skill in the art at present.

[0010] The information disclosed in this background art section is only intended to enhance the overall understanding of the present invention and should not be regarded as an admission or any form of suggestion that this information constitutes prior art already known to those of ordinary skill in the art. Summary of the Invention

[0011] In view of the above technical problems, an embodiment of the present invention provides a high-power ceramic heater for new energy vehicles and a manufacturing method thereof to solve the problems raised in the above background art.

[0012] A high-power ceramic heater for new energy vehicles includes: a ceramic matrix in a hollow tubular shape; and further includes: a temperature sensing layer, a first ceramic substrate, a heating layer, a second ceramic substrate, a first metal layer, and a first electroplated alloy layer that are sequentially attached to the outer side of the ceramic matrix; and a second metal layer and a second electroplated alloy layer that are sequentially attached to the inner side of the ceramic matrix. Among them, the electroplated alloy layer includes, but is not limited to, nickel plating, chromium plating, etc.

[0013] Preferably, the temperature sensing layer is a temperature sensing circuit integrated on the outer side of the ceramic matrix by a printing process using a temperature sensing paste.

[0014] Specifically, the temperature sensing paste contains a certain amount of conductive material and thermosensitive material. When the temperature changes, the thermosensitive material in the temperature sensing paste will undergo corresponding physical changes, resulting in a change in the resistance of the temperature sensing circuit; by detecting this change in resistance, the change in the external temperature can be accurately sensed; the temperature sensing paste material used in this patent is tungsten and alumina.

[0015] Preferably, the raw materials of the heating layer, by mass, include: 57 parts of W, 13 parts of Mo, 3 parts of Al2O3, 5 parts of Re, 5 parts of Ru, and 27 parts of organic solvent.

[0016] Preferably, the raw materials of the first ceramic substrate, by mass, include: 60 parts of Al2O3, 10 parts of cordierite, 10 parts of mullite, and 40 parts of organic solvent; among them, the raw material composition of the first ceramic substrate is the same as that of the second ceramic substrate.

[0017] Preferably, the ceramic matrix, the temperature sensing layer, the heating layer, the first ceramic substrate, the second ceramic substrate, the first metal layer, and the second metal layer are integrally sintered.

[0018] A manufacturing method of a high-power ceramic heater for new energy vehicles according to any one of the above, comprising the following steps: Weigh, mix and ball mill raw materials according to the formulation ratio of each raw material of the heating layer to prepare a heating slurry; Weigh, mix and ball mill raw materials according to the formulation ratio of each raw material of the ceramic substrate to prepare a ceramic slurry, and use the tape casting process to prepare a first ceramic substrate and a second ceramic substrate; Arrange the temperature-sensitive slurry, heating slurry, first metal layer slurry, and second metal layer slurry on the first ceramic substrate and the second ceramic substrate in sequence through the printing process; Perform warm isostatic pressing in sequence to bond the temperature-sensitive layer, heating layer, first metal layer, and second metal layer to the first ceramic substrate and the second ceramic substrate in sequence; Then sinter integrally with the ceramic matrix at high temperature to obtain a high-power ceramic heater; Perform electroplating treatment on the metal layer of the high-power ceramic heater to form a first electroplated alloy layer and a second electroplated alloy layer on the outside of the metal layer.

[0019] Preferably, the tape casting process specifically includes the following steps: Perform vacuum degassing on the ceramic slurry to reduce the gas content in the slurry and make it have a certain viscosity; Pour the ceramic slurry evenly onto the tape casting film, and remove it after it levels and dries to obtain a ceramic substrate.

[0020] Preferably, the above printing process specifically includes the following steps: Pour the temperature-sensitive slurry, heating slurry, and metal layer slurry onto a screen with a specific pattern and mesh number, and place a ceramic substrate under the screen; scrape evenly from above the screen with a squeegee, and the slurry penetrates onto the ceramic substrate to form a corresponding pattern.

[0021] A high-power ceramic heater for new energy vehicles and its manufacturing method provided by an embodiment of the present invention have the following beneficial effects: Through the innovative design of using new heating slurries, new ceramic materials, surface treatment of metal layers and electroplated alloy layers, and integrated temperature-sensitive layers, the high-power ceramic heater not only performs excellently in terms of performance, lifespan, safety, temperature control, and temperature shock resistance, but also can cope with more severe working environments and provide a more stable and efficient heating solution; these innovative designs make the ceramic heater more reliable and durable under high power, high voltage, and complex working conditions. Description of the Drawings

[0022] Figure 1 It is a schematic structural diagram of a common high-power ceramic heater; Figure 2 It is a schematic structural diagram of the high-power ceramic heater in the present invention; Figure 3 This is the process flow chart of the manufacturing method of the high-power ceramic heater in the present invention; Among them, 1 - ceramic matrix; 2 - first ceramic substrate; 3 - second ceramic substrate; 4 - temperature sensing layer; 5 - heating layer; 6 - first metal layer; 7 - first electroplated alloy layer; 8 - second metal layer; 9 - second electroplated alloy layer. Specific embodiments

[0023] Next, the technical solutions in the embodiments of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present invention.

[0024] In view of the above technical problems, the embodiments of the present invention provide a high-power ceramic heater for new energy vehicles and its manufacturing method to solve the problems raised in the above background technology.

[0025] I. Performance test experiment of heating paste Example 1: The new heating paste of the present invention According to the mass parts of the heating layer raw materials, the following proportions of raw materials are weighed respectively: 57 parts of W, 13 parts of Mo, 3 parts of Al2O3, 5 parts of Re, 5 parts of Ru, and 27 parts of organic solvent; Mix the raw materials of the heating layer evenly and put them into a ball mill for ball milling; After the ball milling is completed, the heating paste is obtained; it can be placed at room temperature; Arrange the heating paste on the ceramic substrate through the printing process, and then perform warm isostatic pressing in sequence. After sintering with the ceramic matrix integrally, a high-power ceramic heater is obtained.

[0026] Comparative example 1: Conventional heating paste According to the mass parts of the heating layer raw materials, the following proportions of raw materials are weighed respectively: 57 parts of W, 13 parts of Mo, 3 parts of Al2O3, and 27 parts of organic solvent; Mix the raw materials of the heating layer evenly and put them into a ball mill for ball milling; After the ball milling is completed, the heating paste is obtained; it can be placed at room temperature; Arrange the heating paste on the ceramic substrate through the printing process, and then perform warm isostatic pressing in sequence. After sintering with the ceramic matrix integrally, a common high-power ceramic heater is obtained; the structure of the prepared common high-power ceramic heater is as Figure 1 shown.

[0027] The product performance test data of Example 1 - Comparative Example 1 are shown in Table 1 below: From the data results in Table 1, it can be seen that the main component of the new heating paste used in the high-power ceramic heater prepared by the present invention is tungsten metal. After adding ruthenium and rhenium metals, the temperature coefficient of resistance (abbreviated as TCR) can be effectively reduced, that is, the resistance change caused by temperature change is reduced, the service life of the circuit made of the heating paste is extended, and the resistance attenuation is delayed.

[0028] Table 1

[0029] II. Performance Test Experiment of Ceramic Paste Example 2: The new ceramic paste of the present invention By mass fraction of the raw materials of the heating layer, the following proportions of raw materials are weighed respectively: 57 parts of W, 13 parts of Mo, 3 parts of Al2O3, and 27 parts of organic solvent; Mix the raw materials of the heating layer evenly and put them into a ball mill for ball milling; After the ball milling is completed, the heating paste is obtained; it can be placed at room temperature; By mass fraction of the raw materials of the ceramic substrate, the following proportions of raw materials are weighed respectively: 60 parts of Al2O3, 10 parts of cordierite, 10 parts of mullite, and 40 parts of organic solvent; Mix the ceramic paste evenly, put it into a ball mill for ball milling, prepare the ceramic paste, and use the tape casting process to obtain the ceramic substrate; cut the ceramic substrate to obtain a suitable size; Arrange the heating paste on the ceramic substrate by printing process, and perform warm isostatic pressing in sequence. After sintering with the ceramic matrix as a whole, a high-power ceramic heater is obtained.

[0030] Comparative Example 2: Conventional ceramic paste By mass fraction of the raw materials of the heating layer, the following proportions of raw materials are weighed respectively: 57 parts of W, 13 parts of Mo, 3 parts of Al2O3, and 27 parts of organic solvent; Mix the raw materials of the heating layer evenly and put them into a ball mill for ball milling; After the ball milling is completed, the heating paste is obtained; it can be placed at room temperature; By mass fraction of the raw materials of the ceramic substrate, the following proportions of raw materials are weighed respectively: 60 parts of Al2O3 and 40 parts of organic solvent; Mix the raw materials of the ceramic substrate evenly, put it into a ball mill for ball milling, prepare the ceramic paste, and use the tape casting process to obtain the ceramic substrate; cut the ceramic substrate to obtain a suitable size; Arrange the heating paste on the ceramic substrate by printing process, and perform warm isostatic pressing in sequence. After sintering with the ceramic matrix as a whole, a high-power ceramic heater is obtained.

[0031] The product performance test data of Example 2 - Comparative Example 2 are shown in Table 2 below: From the data results in Table 2, it can be seen that the main component of the new ceramic material used in the high-power ceramic heater prepared by the present invention is alumina ceramic. After adding cordierite and mullite, the thermal expansion coefficient of the ceramic can be effectively reduced, and the generation of thermal stress can be reduced.

[0032] The ceramic heaters made of conventional ceramic slurries and the ceramic heaters made of the new ceramic material were respectively subjected to thermal shock tests. When the ceramic heaters were heated to a certain temperature and then suddenly quenched in water, the limit temperature difference at which the ceramic heaters cracked was measured; as can be seen from Table 2, the present invention has a larger range of limit temperature differences.

[0033] Table 2

[0034] III. Performance Test Experiment of Surface Metal Coating and Electroplated Alloy Layer Example 3: Surface Metal Coating and Electroplated Alloy Layer According to the mass parts of each raw material of the heating layer, the following proportions of raw materials were respectively weighed: 57 parts of W, 13 parts of Mo, 3 parts of Al2O3, and 27 parts of organic solvent; The raw materials of the heating layer were mixed evenly and put into a ball mill for ball milling; After the ball milling was completed, the heating slurry was obtained; it can be placed at room temperature; According to the mass parts of each raw material of the ceramic substrate, the following proportions of raw materials were respectively weighed: 60 parts of Al2O3 and 40 parts of organic solvent; The raw materials of the ceramic substrate were mixed evenly, put into a ball mill for ball milling, the ceramic slurry was prepared, and the ceramic substrate was obtained by using the tape casting process; the appropriate size was obtained by cutting the ceramic substrate; The heating slurry and the metal layer slurry were arranged on the ceramic substrate by printing process, followed by warm isostatic pressing, and a high-power ceramic heater was obtained after sintering integrally with the ceramic matrix; The metal layer of the high-power ceramic heater was electroplated to form electroplated alloy layers on both the inner and outer sides of the ceramic matrix.

[0035] Comparative Example 3: No Surface Metal Coating and Electroplated Alloy Layer According to the mass parts of each raw material of the heating layer, the following proportions of raw materials were respectively weighed: 57 parts of W, 13 parts of Mo, 3 parts of Al2O3, and 27 parts of organic solvent; The raw materials of the heating layer were mixed evenly and put into a ball mill for ball milling; After the ball milling was completed, the heating slurry was obtained; it can be placed at room temperature; According to the mass parts of each raw material of the ceramic substrate, the following proportions of raw materials were respectively weighed: 60 parts of Al2O3 and 40 parts of organic solvent; Mix the raw materials of the ceramic substrate evenly, put them into a ball mill for ball milling to prepare a ceramic slurry, and use the tape casting process to obtain the ceramic substrate; cut the ceramic substrate to obtain a suitable size; Apply the heating slurry on the ceramic substrate through the printing process, perform warm isostatic pressing in sequence, and sinter it integrally with the ceramic matrix to obtain a high-power ceramic heater.

[0036] The product performance test data of Example 3 - Comparative Example 3 are as follows in Table 3: It can be seen from the data results in Table 3 that coating (including but not limited to coating, sputtering, printing) a 20μm - 50μm metal layer on the surface of the high-power ceramic heater and preparing a coating layer by electroplating can increase the thermal conductivity, thereby enhancing the temperature shock resistance of the ceramic heater, improving the maximum power density that the ceramic heater can bear, and the service life can reach 10 years.

[0037] Apply a high voltage of 750V to the high-power ceramic heater, and conduct a power-on cycle test of 1 minute of power-on - 15 seconds of power-off under the conditions of the same cooling water temperature (10°C) and flow rate (5L / min). The high-power ceramic heater with a metal layer and a coating layer can reach 50,000 cycles without damage.

[0038] It can be seen from the above analysis that coating the metal on the inner wall of the ceramic substrate and the surface of the outermost ceramic substrate can quickly conduct heat and reduce the generation of thermal stress in the ceramic heater; preparing an alloy layer by electroplating on the surface of the metal layer can further increase the thermal conductivity and play a role in delaying the oxidation of the metal layer.

[0039] Table 3

[0040] IV. Performance Test Experiment of the Temperature Sensing Layer Example 4: Sintered with a temperature sensing layer Weigh the raw materials in the following proportions according to the mass parts of the raw materials of the heating layer: 57 parts of W, 13 parts of Mo, 3 parts of Al2O3, and 27 parts of organic solvent; Mix the raw materials of the heating layer evenly and put them into a ball mill for ball milling; After the ball milling is completed, obtain the heating slurry; it can be placed at room temperature; Weigh the raw materials in the following proportions according to the mass parts of the raw materials of the ceramic substrate: 60 parts of Al2O3 and 40 parts of organic solvent; Mix the raw materials of the ceramic substrate evenly, put them into a ball mill for ball milling to prepare a ceramic slurry, and use the tape casting process to obtain the ceramic substrate; cut the ceramic substrate to obtain a suitable size; The heating paste and the temperature-sensitive layer paste (by mass fraction, 65 parts of tungsten and 35 parts of Al2O3) are arranged on the ceramic substrate through a printing process, and then warm isostatic pressing is carried out. After sintering integrally with the ceramic matrix, a high-power ceramic heater is obtained; the specific preparation process is as follows Figure 3 shown, and the structure of the prepared ceramic heater is as follows Figure 2 shown.

[0041] Comparative Example 4: No temperature-sensitive layer is provided According to the mass fraction of each raw material of the heating layer, the following proportions of raw materials are weighed respectively: 57 parts of W, 13 parts of Mo, 3 parts of Al2O3 and 27 parts of organic solvent; Mix the raw materials of the heating layer evenly and put them into a ball mill for ball milling; After the ball milling is completed, the heating paste is obtained; it can be placed at room temperature; According to the mass fraction of each raw material of the ceramic substrate, the following proportions of raw materials are weighed respectively: 60 parts of Al2O3 and 40 parts of organic solvent; Mix the raw materials of the ceramic substrate evenly, put them into a ball mill for ball milling, prepare the ceramic slurry, and use the tape casting process to obtain the ceramic substrate; cut the ceramic substrate to obtain a suitable size; Arrange the heating paste on the ceramic substrate through a printing process, and then carry out warm isostatic pressing. After sintering integrally with the ceramic matrix, a high-power ceramic heater is obtained.

[0042] Integrate the temperature-sensing circuit into the high-power ceramic heater through a printing process and sinter it integrally. The temperature-sensitive layer can be closely attached to the heating layer, acting as a temperature sensor with a response rate ≤ 100 ms; and the TCR value of the temperature-sensitive paste can reach 5000 PPM after sintering, so the temperature measurement is sensitive.

[0043] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A high-power ceramic heater for new energy vehicles, comprising: A hollow tubular ceramic substrate; characterized in that it also includes: A temperature-sensitive layer, a first ceramic substrate, a heating layer, a second ceramic substrate, a first metal layer and a first electroplated alloy layer are sequentially attached to the outside of the ceramic substrate; And, a second metal layer and a second electroplated alloy layer are sequentially attached to the inner side of the ceramic substrate.

2. The high-power ceramic heater for new energy vehicles according to claim 1, wherein The temperature sensing layer is a temperature sensing circuit that is integrated on the outside of the ceramic substrate by a printing process using temperature sensing slurry.

3. The high-power ceramic heater for new energy vehicles according to claim 1, characterized in that, The raw materials of the heating layer include, by mass, 57 parts of W, 13 parts of Mo, 3 parts of Al2O3, 5 parts of Re, 5 parts of Ru and 27 parts of organic solvent.

4. The high-power ceramic heater for new energy vehicles according to claim 1, wherein, The raw materials of the first ceramic substrate include, by mass, 60 parts of Al2O3, 10 parts of cordierite, 10 parts of mullite and 40 parts of an organic solvent; wherein the raw material composition of the first ceramic substrate is the same as the raw material composition of the second ceramic substrate.

5. The high-power ceramic heater for new energy vehicles according to claim 1, characterized in that, The ceramic substrate, the temperature sensing layer, the heating layer, the first ceramic substrate, the second ceramic substrate, the first metal layer and the second metal layer are sintered integrally.

6. A manufacturing method of a high-power ceramic heater for new energy vehicles as described in any one of claims 1-5, characterized in that, The following steps are involved: The raw materials are weighed, mixed and ball-milled according to the formula ratio of each raw material of the heating layer to prepare the heating slurry; Weighing, mixing and ball-milling the raw materials according to the formula ratio of each raw material of the ceramic substrate, preparing ceramic slurry, and preparing the first ceramic substrate and the second ceramic substrate by using a tape casting process; Arranging the temperature-sensitive paste, the heat-generating paste, the first metal layer paste, and the second metal layer paste on the first ceramic substrate and the second ceramic substrate in sequence through a printing process; Performing warm isostatic pressing in sequence to sequentially bond the temperature-sensitive layer, the heat-generating layer, the first metal layer, and the second metal layer to the first ceramic substrate and the second ceramic substrate; Then it is sintered together with the ceramic substrate at high temperature to obtain a high-power ceramic heater; The metal layer of the high-power ceramic heater is electroplated to form a first electroplated alloy layer and a second electroplated alloy layer on the outer side of the metal layer.

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