Thermal battery heat insulation structure and preparation method thereof

Abstract

The invention discloses a thermal battery thermal insulation structure and a preparation method thereof, the structure comprises a thermal insulation layer A, a thermal insulation layer B and a connecting layer, the thermal insulation layer A wraps a thermal battery, and the connecting layer is arranged between the thermal insulation layer A and the thermal insulation layer B. The heat insulation structure is smooth, has silver luster and can effectively reflect light and reduce radiative heat transfer, the heat insulation layer A has the advantages of being thin and soft in texture, the shaping effect is good, the heat insulation layer A can be tightly attached to the thermal battery and the heat insulation layer B, the gap space is reduced, and the heat insulation layer A and the heat insulation layer B are tightly connected through the connecting layer. Therefore, the structure can be applied to a low-surface-temperature thermal battery needing long-time power supply.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery preparation, and in particular relates to a thermal battery insulation structure and a preparation method thereof. Background Art

[0002] Thermal batteries are different from conventional batteries. Their most important feature is that they have a high temperature working environment. Under normal circumstances, the internal temperature of thermal batteries will be greater than 550°C, and then they will undergo heat conduction. In this case, the surface temperature of the thermal battery will reach 150°C to 250°C. Thermal batteries have extremely high reliability and stability. The electrolyte does not conduct ions at room temperature, so the self-discharge of thermal batteries is extremely small. Thermal batteries have relatively wide requirements for the environment when they are working. When using thermal batteries, they are mainly used to provide electrical energy for the missile system. However, during use, once the surface temperature of the thermal battery is too high, it will obviously exceed the temperature tolerance range of the missile system, and ultimately reduce its use effect. It can be seen that the surface temperature of the thermal battery will have a more serious impact on the use of the thermal battery. Once its surface temperature is too high, it will directly affect the safety and reliability of the use of electronic components on the missile, which is also one of the reasons why the use of thermal batteries is limited.

[0003] Secondly, the internal electrolyte of the thermal battery is molten salt. At room temperature, the electrolyte is not melted and cannot conduct ions. When the ignition device activates the surrounding heating material during use, the battery will use the heat source to melt and activate the electrolyte. The electrolyte melts and conducts ions. At the same time, the positive and negative active materials of the thermal battery undergo electrochemical reactions and output current, and finally the function and performance of a primary reserve battery can be effectively exerted. Inside the entire thermal battery, the average temperature is about 550°C, and the heat is conducted to the battery shell through the wrapping layer, resulting in heat loss. Therefore, under certain internal heat conditions of the thermal battery, the better the insulation effect of the wrapping layer, the slower the internal heat loss, and the longer the normal operation of the thermal battery can be maintained. Parameter optimization such as the type, thickness and use combination of the wrapping layer can improve its insulation effect to reduce heat wave loss, thereby improving the electrochemical performance of the thermal battery, while reducing the surface temperature and improving the safety and reliability of the battery.

[0004] The patent document with the announcement number CN116922924A discloses a composite thermal insulation material and thermal insulation protection method for lithium-ion batteries. The five-layer thermal insulation structure of shell-flexible aerogel felt-aluminum foil-air-EVA foam-aerogel powder-battery maintains the constant temperature of the lithium battery during discharge. Especially for lithium batteries used in harsh environments such as high temperature exposure in summer or extreme cold in winter, it can effectively increase the discharge voltage of the battery, increase the discharge capacity of the battery, and maintain the temperature of the battery so that the electrical equipment can operate normally. The invention sets an air layer, and the outer layers are not tightly connected; at the same time, the aerogel powder is used to fill the gap between the lithium-ion battery and the EVA closed-cell foam insulation support structure. The aerogel powder needs to be filled after the EVA closed-cell foam support structure is set, and the preparation process requires high precision.

[0005] The patent document with announcement number CN117926365A discloses an aluminum foil for lithium batteries and its preparation method. The preparation method comprises: S1: subjecting the aluminum foil to multi-stage formation to obtain an aluminum foil with an aluminum oxide film layer on the surface; S2: subjecting the aluminum foil with an aluminum oxide film layer on the surface to phosphoric acid treatment, first pure water washing, sodium silicate treatment, second pure water washing, first roasting, sodium removal treatment, third pure water washing, second roasting, diammonium phosphate treatment, fourth pure water treatment and drying in sequence to obtain an aluminum foil for lithium batteries; wherein the reagent used in the sodium removal treatment is a mixed aqueous solution of glycine, oxalic acid and citric acid. The preparation method provided by the invention can prepare an aluminum foil for lithium batteries with a dense oxide film layer, but no other wrapping layer is added to the outer layer of the aluminum foil to improve the thermal insulation effect. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a thermal battery insulation structure and a preparation method thereof.

[0007] The present invention is achieved through the following technical solutions.

[0008] The present invention provides a thermal battery insulation structure, comprising a thermal insulation layer A, a thermal insulation layer B and a connecting layer, wherein the thermal insulation layer A covers the thermal battery, and the connecting layer is arranged between the thermal insulation layer A and the thermal insulation layer B.

[0009] Preferably, 1 to 5 layers of thermal insulation layer A are respectively arranged on the inner and outer sides of the thermal insulation layer B.

[0010] Preferably, the thickness of the thermal insulation layer A includes at least one of 0.01 mm, 0.02 mm, 0.03 mm, and 0.04 mm.

[0011] Preferably, the thermal insulation layer A is made of aluminum foil, and the connecting layer is made of liquid sodium silicate.

[0012] Preferably, the liquid sodium silicate has a solid content of 36-60% and a Baume degree of 40-60Be.

[0013] Preferably, the material of the thermal insulation layer B includes one of glass fiber tape, thermal insulation paper, fiber felt, and aerogel.

[0014] Preferably, the thermal insulation paper is made of asbestos.

[0015] Preferably, the aerogel is a silica aerogel.

[0016] A method for preparing a thermal battery insulation structure comprises the following steps:

[0017] S1: vacuum-dry the heat insulation layer A and the heat insulation layer B to be used.

[0018] S2: After wrapping the thermal battery with the thermal insulation layer A, the outermost thermal insulation layer A is connected to the thermal insulation layer B through a connecting layer, and the outer side of the thermal insulation layer B is connected to the thermal insulation layer A through a connecting layer, and then vacuum drying is performed to obtain the thermal battery insulation structure.

[0019] Preferably, in both steps S1 and S2, vacuum drying is performed at a temperature of 70-90° C. for 8-12 hours.

[0020] The beneficial effects of the present invention are:

[0021] The heat insulation structure of the present invention is smooth and has a silver luster, can effectively reflect light, and reduce radiation heat transfer. The heat insulation layer A is thin and soft, and has a good shaping effect, and can be closely attached to the thermal battery and the heat insulation layer B, reducing the gap space, and the heat insulation layer A and the heat insulation layer B are closely connected through the connecting layer. Therefore, the structure can be applied to thermal batteries that need to supply power for a long time and have a low surface temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a comparison diagram of surface temperature curves of Example 1 of the present invention and Comparative Example 1;

[0023] Figure 2 1 is a comparison diagram of discharge curves of Example 1 of the present invention and Comparative Example 1;

[0024] Figure 3 It is a schematic diagram of the structure of the present invention;

[0025] In the figure: 1-insulation layer A, 2-insulation layer B, 3-connection layer, 4-thermal battery. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0027] Embodiment 1:

[0028] like Figure 3 As shown, a thermal battery insulation structure comprises a thermal insulation layer A1, a thermal insulation layer B2 and a connecting layer 3, wherein the thermal insulation layer A1 covers a thermal battery 4, and the connecting layer 3 is arranged between the thermal insulation layer A1 and the thermal insulation layer B2.

[0029] Two layers of thermal insulation layers A1 are respectively arranged on the inner and outer sides of the thermal insulation layer B2, so that the thermal insulation structure has a good thermal insulation effect, and its working retention time and surface temperature reduction are significantly better than the thermal insulation structure in the prior art.

[0030] The thickness of the heat insulation layer A1 is 0.01mm and 0.03mm. The aluminum foil with this thickness is smooth and has a silver luster, which can effectively reflect light and reduce radiation heat transfer; at the same time, it is thin and soft, has a good shaping effect, and can be closely attached to the heat insulation layer B2 and the thermal battery 4 to reduce the gap space.

[0031] The material of the heat insulation layer A1 is aluminum foil, and the material of the connection layer 3 is liquid sodium silicate.

[0032] The solid content of the liquid sodium silicate is 47% and the Baume degree is 50 Be. The liquid sodium silicate with this value can ensure the pasting effect while ensuring that the liquid sodium silicate has good bonding strength to prevent the thermal insulation layer A1 from separating from the thermal insulation layer B2.

[0033] The material of the heat insulation layer B2 includes glass fiber tape.

[0034] A method for preparing a thermal battery insulation structure comprises the following steps:

[0035] S1: vacuum drying the heat insulation layer A1 and the heat insulation layer B2 to be used,

[0036] S2: After wrapping the thermal battery 4 with a thermal insulation layer A1 with a thickness of 0.01 mm and setting two layers, the outermost thermal insulation layer A1 is connected to the thermal insulation layer B2 through a connecting layer 3, and the outer side of the thermal insulation layer B2 is connected to the thermal insulation layer A1 through a connecting layer 3. The thermal insulation layer A1 outside the thermal insulation layer B2 has a thickness of 0.03 mm and is set in two layers. Then, vacuum drying is performed to obtain the thermal battery insulation structure.

[0037] In both steps S1 and S2, vacuum drying is performed at 80° C. for 10 hours.

[0038] Embodiment 2:

[0039] like Figure 3 As shown, a thermal battery insulation structure comprises a thermal insulation layer A1, a thermal insulation layer B2 and a connecting layer 3, wherein the thermal insulation layer A1 covers a thermal battery 4, and the connecting layer 3 is arranged between the thermal insulation layer A1 and the thermal insulation layer B2.

[0040] A layer of heat insulation layer A1 is respectively arranged on the inner and outer sides of the heat insulation layer B2, so that the heat insulation structure has a good heat insulation effect, and its working retention time and surface temperature reduction are significantly better than the heat insulation structure in the prior art.

[0041] The thickness of the heat insulation layer A1 is 0.02 mm. The aluminum foil with this thickness is smooth and has a silver luster, which can effectively reflect light and reduce radiation heat transfer; at the same time, it is thin and soft, has a good shaping effect, and can be closely attached to the heat insulation layer B2 and the thermal battery 4 to reduce the gap space.

[0042] The material of the heat insulation layer A1 is aluminum foil, and the material of the connection layer 3 is liquid sodium silicate.

[0043] The solid content of the liquid sodium silicate is 36%, and the Baume degree is 40 Be. The liquid sodium silicate with this value can ensure the pasting effect while ensuring that the liquid sodium silicate has good bonding strength to prevent the thermal insulation layer A1 from separating from the thermal insulation layer B2.

[0044] The material of the heat insulation layer B2 is heat insulation paper, and the material of the heat insulation paper is asbestos.

[0045] A method for preparing a thermal battery insulation structure comprises the following steps:

[0046] S1: vacuum drying the heat insulation layer A1 and the heat insulation layer B2 to be used,

[0047] S2: After wrapping the thermal battery 4 with a thermal insulation layer A1 with a thickness of 0.02 mm and setting one layer, the outermost thermal insulation layer A1 is connected to the thermal insulation layer B2 through a connecting layer 1, and the outer side of the thermal insulation layer B2 is connected to the thermal insulation layer A1 through a connecting layer 3. The thermal insulation layer A1 outside the thermal insulation layer B2 has a thickness of 0.02 mm and is set as one layer, and then vacuum dried to obtain the thermal battery insulation structure.

[0048] In both steps S1 and S2, vacuum drying is performed at 70° C. for 8 hours.

[0049] Embodiment 3:

[0050] like Figure 3 As shown, a thermal battery insulation structure comprises a thermal insulation layer A1, a thermal insulation layer B2 and a connecting layer 3, wherein the thermal insulation layer A1 covers a thermal battery 4, and the connecting layer 3 is arranged between the thermal insulation layer A1 and the thermal insulation layer B2.

[0051] Five layers of thermal insulation layers A1 are respectively arranged on the inner and outer sides of the thermal insulation layer B2, so that the thermal insulation structure has a good thermal insulation effect, and its working retention time and surface temperature reduction are significantly better than the thermal insulation structure in the prior art.

[0052] The thickness of the heat insulation layer A1 is 0.04 mm. The aluminum foil at this thickness is smooth and has a silver luster, which can effectively reflect light and reduce radiation heat transfer; at the same time, it is thin and soft, has a good shaping effect, and can be closely attached to the heat insulation layer B2 and the thermal battery 4 to reduce the gap space.

[0053] The material of the heat insulation layer A1 is aluminum foil, and the material of the connection layer 3 is liquid sodium silicate.

[0054] The solid content of the liquid sodium silicate is 60%, and the Baume degree is 60 Be. The liquid sodium silicate with this value can ensure the pasting effect while ensuring that the liquid sodium silicate has good bonding strength to prevent the thermal insulation layer A1 from separating from the thermal insulation layer B2.

[0055] The thermal insulation layer B2 is made of silicon dioxide aerogel.

[0056] A method for preparing a thermal battery insulation structure comprises the following steps:

[0057] S1: vacuum drying the heat insulation layer A1 and the heat insulation layer B2 to be used,

[0058] S2: After wrapping the thermal battery 4 with a thermal insulation layer A1 with a thickness of 0.04 mm and arranging 5 layers, the outermost thermal insulation layer A1 is connected to the thermal insulation layer B2 through the connecting layer 3, and the outer side of the thermal insulation layer B2 is connected to the thermal insulation layer A1 through the connecting layer 3. The thermal insulation layer A1 outside the thermal insulation layer B2 has a thickness of 0.04 mm and is arranged in 5 layers, and then vacuum drying is performed to obtain the thermal battery insulation structure.

[0059] In both steps S1 and S2, vacuum drying is performed at 90° C. for 12 hours.

[0060] Comparative Example 1:

[0061] The thermal battery insulation structure is provided with only one insulation layer B2, the insulation layer B2 is made of silicon dioxide aerogel, and the corresponding preparation method is the same as that of Example 1.

[0062] Among them, Example 1 is the best example. The thermal battery wrapped with the heat insulation structure of Example 1 and Comparative Example 1 was tested. The results are as follows: Figure 2 , 3 As shown. Figure 1 In the comparison of the surface temperature curves, the maximum surface temperature of the thermal insulation structure of Example 1 is about 160°C, and the maximum surface temperature of the thermal insulation structure of Comparative Example 1 is about 180°C. Figure 2In the comparison of the discharge curves, it can be seen that the voltage of Example 1 after 200s is higher than that of Comparative Example 1, and the voltage value of Comparative Example 1 shows a significant downward trend after 700s. It can be seen that the thermal insulation performance of the present invention is better, and the thermal battery can be kept warm for a longer time. Comparative Example 1 is a common technology in existing production, which shows that the mechanism of the present application is superior to the existing technology.

Claims

1. A thermal battery insulation structure, characterized in that: The invention comprises a heat insulation layer A (1), a heat insulation layer B (2) and a connection layer (3), wherein the heat insulation layer A (1) covers a thermal battery (4), and the connection layer (3) is arranged between the heat insulation layer A (1) and the heat insulation layer B (2).

2. A thermal battery insulation structure as claimed in claim 1, characterized in that: 1 to 5 layers of thermal insulation layers A (1) are respectively arranged on the inner and outer sides of the thermal insulation layer B (2).

3. A thermal battery insulation structure as claimed in claim 1, characterized in that: The thickness of the thermal insulation layer A (1) includes at least one of 0.01 mm, 0.02 mm, 0.03 mm, and 0.04 mm.

4. A thermal battery insulation structure as claimed in claim 1, characterized in that: The heat insulation layer A (1) is made of aluminum foil, and the connection layer (3) is made of liquid sodium silicate.

5. A thermal battery insulation structure as claimed in claim 4, characterized in that: The liquid sodium silicate has a solid content of 36-60% and a Baume degree of 40-60Be.

6. A thermal battery insulation structure as claimed in claim 1, characterized in that: The material of the thermal insulation layer B (2) includes one of glass fiber tape, thermal insulation paper, fiber felt, and aerogel.

7. A thermal battery insulation structure as claimed in claim 6, characterized in that: The thermal insulation paper is made of asbestos.

8. A thermal battery insulation structure as claimed in claim 6, characterized in that: The aerogel is a silicon dioxide aerogel.

9. A method for preparing a thermal battery insulation structure according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: vacuum drying the heat insulation layer A (1) and the heat insulation layer B (2) to be used for later use; S2: After wrapping the thermal battery (4) with the thermal insulation layer A (1), the outermost thermal insulation layer A (1) is connected to the thermal insulation layer B (2) via a connecting layer (3), and the outer side of the thermal insulation layer B (2) is connected to the thermal insulation layer A (1) via a connecting layer (3), and then vacuum drying is performed to obtain a thermal battery insulation structure.

10. The method for preparing a thermal battery insulation structure according to claim 9, characterized in that: In both steps S1 and S2, vacuum drying is performed at a temperature of 70-90° C. for 8-12 hours.

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