Thermal runaway-proof capsule and manufacturing process thereof, thermal runaway-proof battery and manufacturing method thereof

Abstract

The present invention relates to battery material technology, and specifically to an anti-thermal runaway capsule and a manufacturing process thereof, an anti-thermal runaway battery and a manufacturing method thereof. The anti-thermal runaway capsule has a capsule shell, and the capsule shell is provided with an anti-thermal runaway material. The material of the capsule shell is polyethylene modified by calcium carbonate and stearic acid, and the anti-thermal runaway material is red phosphorus. The capsule shell of the anti-thermal runaway capsule improves the diffusion capacity of calcium carbonate through water bath heating, prevents calcium carbonate from agglomerating, and improves the mechanical stability of the capsule, so that the capsule can be inserted from the injection hole without breaking. After the anti-thermal runaway capsule is made into a battery, it can melt when the temperature is too high to release the anti-battery thermal runaway material.

Description

Technical Field

[0001] The present invention relates to battery material technology, and in particular to a thermal runaway prevention capsule and a manufacturing process thereof, a thermal runaway prevention battery and a manufacturing method thereof. Background Art

[0002] With the vigorous development of the new energy industry, the energy storage industry has also gradually emerged, and energy storage batteries have received widespread attention. However, during the transportation or use of energy storage batteries, the batteries are affected by environmental or external factors, and there is a risk of short circuit inside the batteries. With the short circuit of the battery, the temperature inside the battery rises sharply, and the battery shell expands sharply, causing the explosion-proof valve in the battery top cover to explode, causing the electrolyte and combustible gas inside the battery to spray out. After that, the electrolyte combustible gas comes into contact with oxygen and burns, causing a fire.

[0003] In order to reduce the occurrence of such situations, a method of mixing flame retardants with electrolytes is currently used, but this method will directly affect the ion conductivity efficiency of the battery electrolyte.

[0004] If the electrolyte is isolated from the flame retardant by using a capsule method, the electrolyte conduction efficiency will not be affected. However, this capsule device has a technical problem of not being easy to place in the battery in advance, because if it is added to the battery shell in advance, the capsule device will compress the shell space, making it impossible for the bare battery cell to enter the shell, thus affecting the battery assembly. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and provide a thermal runaway proof capsule and a manufacturing process thereof, a thermal runaway proof battery and a manufacturing method thereof.

[0006] The technical solution for achieving the purpose of the present invention is: a thermal runaway prevention capsule, comprising a capsule shell, wherein the capsule shell is provided with a thermal runaway prevention material, and the capsule shell (1) is made of polyethylene modified by salt and organic compounds.

[0007] The salt is calcium carbonate, and the organic compound is stearic acid.

[0008] The thermal runaway prevention material described in the above technical solution is red phosphorus.

[0009] The present invention also provides a manufacturing process for a thermal runaway-proof capsule.

[0010] The thermal runaway prevention capsule comprises the following steps:

[0011] S1, preparing temperature-sensitive materials;

[0012] S2, using temperature-sensitive materials to perform plastic deformation to create the shape of the capsule shell,

[0013] S3, put thermal runaway protection materials inside;

[0014] S4, fasten the capsule shell and increase the temperature to make the capsule airtight.

[0015] In the above technical solution S1, the method for preparing the temperature sensitive material comprises the following steps:

[0016] Step 1, heating the calcium carbonate in a water bath and then filtering it out;

[0017] Step 2, mixing the filtered calcium carbonate and stearic acid in ethanol;

[0018] Step 3: Dry the mixed calcium carbonate and stearic acid and add polyethylene.

[0019] In step 1 of the above technical solution, the water bath heating temperature is 65°C to 90°C

[0020] In step 1 of the above technical solution, the water bath heating time is 10 to 20 minutes.

[0021] In step 2 of the above technical solution, the mass percentage of stearic acid is 3%.

[0022] The present invention also provides a thermal runaway prevention battery, using the thermal runaway prevention capsule, comprising a shell, a liquid injection hole is provided on the top of the shell, and the thermal runaway prevention capsule is placed into the interior of the shell through the liquid injection hole.

[0023] The present invention also provides a method for manufacturing a thermal runaway-proof battery, comprising the following preparation steps:

[0024] ① Prepare the bare battery cells, shell, top cover, bottom support plate, Mylar film, connecting piece, and thermal runaway protection capsule of the battery;

[0025] ②Ultrasonic welding of the bare cell tabs and the connecting pieces;

[0026] ③Laser weld the connecting piece with bare battery cells to the top cover;

[0027] ④Hot-melt the bottom support plate and the Mylar film;

[0028] ⑤Wrap the bare battery cell with Mylar film with a bottom support plate, and hot-melt the Mylar film with the lower plastic of the top cover;

[0029] ⑥ Install the sample melted in step ⑤ in the housing and perform laser welding;

[0030] ⑦ Carry out helium inspection, formation, volume separation and other related inspections and activations;

[0031] ⑧Insert the thermal runaway prevention capsule into the battery from the injection hole and seal it.

[0032] The sealing described in the above technical solution uses an anti-thermal runaway capsule to block the injection hole.

[0033] In the above technical solution, after sealing in step ⑧, a metal sealing pin is placed above the injection hole and laser welded.

[0034] After adopting the above technical solution, the present invention has the following positive effects:

[0035] The capsule shell of the anti-thermal runaway capsule of the present invention improves the diffusion capacity of calcium carbonate by water bath heating, prevents calcium carbonate from agglomerating, and improves the mechanical stability of the capsule, so that the capsule can be inserted into the battery from the injection hole without breaking. After the anti-thermal runaway capsule is made into a battery, it can melt when the temperature is too high to release the anti-battery thermal runaway material. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the structure of the thermal runaway prevention capsule of the present invention;

[0037] Figure 2 This is a schematic diagram of placing the thermal runaway prevention capsule of the present invention into a battery;

[0038] Figure 3 Cross-sectional view of a battery made of the thermal runaway protection capsule of the present invention

[0039] Figure 4 for Figure 3 A is an enlarged schematic diagram;

[0040] Figure 5 for Figure 4 A magnified schematic diagram of B. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0044] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0045] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0046] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] (Example 1)

[0048] See Figure 1 The present invention provides an anti-thermal runaway capsule, comprising a capsule shell 1, wherein the capsule shell 1 is provided with an anti-thermal runaway material 2, and the capsule shell 1 is made of polyethylene modified by calcium carbonate and stearic acid. The anti-thermal runaway material 2 is red phosphorus. Polyethylene is a temperature-sensitive material, because calcium carbonate and stearic acid are added to PE. Since the added calcium carbonate particles are large, agglomeration is easily generated during the addition process, and excessive addition will increase the rigidity of the polymer. For this purpose, the surface energy of calcium carbonate needs to be reduced, and for this purpose, stearic acid is added to reduce the surface energy of calcium carbonate to make it easier to compound with PE material. The PE material after adding calcium carbonate improves the mechanical strength and thermal conductivity of PE, and can accelerate the decomposition of PE.

[0049] A manufacturing process for thermal runaway-proof capsules.

[0050] The thermal runaway prevention capsule comprises the following steps:

[0051] S1, preparing temperature-sensitive materials;

[0052] S2, using the temperature-sensitive material to perform plastic deformation to produce the shape of the capsule shell 1,

[0053] S3, placing thermal runaway prevention material 2 inside;

[0054] S4, fasten the capsule shell 1 and increase the temperature to make the capsule airtight.

[0055] In S1, the method for preparing the temperature sensitive material comprises the following steps:

[0056] The calcium carbonate is heated in a water bath at 65°C to 70°C, 75°C to 80°C, and 85°C to 90°C, respectively, and the heating time is 10, 15, and 20 minutes, and then filtered out; during the heating process, the surface of the calcium carbonate particles will be further corroded, and tiny pits will form on the surface, which will increase the binding of the calcium carbonate surface to stearic acid, and then the calcium carbonate is filtered out. It is then mixed and dried with 3% stearic acid and placed in an ethanol solution for mixing and drying, and then the calcium carbonate containing stearic acid is added to PE.

[0057] Observe the surface reduction effect of calcium carbonate under different water bath heating effects. 5g of calcium carbonate heated in different water baths was selected and placed in a plunger measuring cylinder and liquid paraffin was added to make up to 50ml. The diffusion was observed after 30 minutes, as shown in Tables 1 to 3 below.

[0058] Heating temperature (℃) 65～70 75～80 85～90 Heating time (min) 10 10 10 Particle sedimentation (ml / min) 0.88 0.97 1.13

[0059] Table 1

[0060] Heating temperature (℃) 65～70 75～80 85～90 Heating time (min) 15 15 15 Particle sedimentation (ml / min) 1.18 1.22 1.26

[0061] Table 2

[0062] Heating temperature (℃) 65～70 75～80 85～90 Heating time (min) 20 20 20 Particle sedimentation (ml / min) 1.21 1.42 1.33

[0063] Table 3

[0064] From the table we can see that calcium carbonate has the best diffusion effect after being heated at 75℃~80℃ for 20 minutes. Therefore, it is least likely to agglomerate when added to PE. Therefore, this method is used to modify calcium carbonate to improve the mechanical strength of PE.

[0065] Advantages: Through the material modification method, the capsule shell 1 of the thermal runaway capsule has good mechanical stability and the characteristics of melting at a certain temperature. 1. The capsule can be successfully placed inside the battery, improving the feasibility of the device; 2. Isolate the electrolyte from the anti-battery thermal runaway material without destroying the performance of the electrolyte; 3. Melt at a temperature of 100℃-200℃, release the anti-battery thermal runaway material, and prevent battery thermal runaway

[0066] (Example 2)

[0067] See Figures 1 to 5 The present invention also provides a thermal runaway-proof battery, using the thermal runaway-proof capsule, including a shell 3, an injection hole 4 is provided above the shell 3, and the thermal runaway-proof capsule is placed into the shell 3 from the injection hole 4. By designing a capsule device to prevent thermal runaway, a capsule-like principle is utilized. When the battery temperature is too high, the outer wall of the capsule melts to release the internal thermal runaway-proof material to prevent a series of effects caused by thermal runaway of the battery. And by modifying the material of the outer wall of the capsule so that it melts at a certain temperature, the mechanical strength of the capsule is further improved.

[0068] The method for manufacturing the thermal runaway-proof battery comprises the following preparation steps:

[0069] ① Prepare the bare battery cell, shell 3, top cover, bottom support plate, Mylar film, connecting sheet, and thermal runaway protection capsule of the battery; the battery also includes poles, sealing rings, explosion-proof valves, explosion-proof valve protection sheets, bare aluminum sheets, upper plastic, lower plastic, thermal runaway protection capsules, metal sealing nails, etc., which are conventional components of existing batteries and will not be described in detail here, which should not affect the understanding of those skilled in the art.

[0070] ②Ultrasonic welding of the bare cell tabs and the connecting pieces;

[0071] ③Laser weld the connecting piece with bare battery cells to the top cover;

[0072] ④Hot-melt the bottom support plate and the Mylar film;

[0073] ⑤Wrap the bare battery cell with Mylar film with a bottom support plate, and hot-melt the Mylar film with the lower plastic of the top cover;

[0074] ⑥ Install the sample melted in step ⑤ in the housing 3 and perform laser welding;

[0075] ⑦ Carry out helium inspection, formation, volume separation and other related inspections and activations;

[0076] ⑧ Insert the thermal runaway prevention capsule into the battery from the injection hole 4 and seal it.

[0077] The sealing uses a thermal runaway prevention capsule to block the injection hole 4. The thermal runaway prevention capsule used for sealing here is larger than the thermal runaway prevention capsule inserted into the battery, and is preferably able to block the injection hole 4.

[0078] After sealing in step ⑧, a metal sealing pin 5 is placed above the injection hole 4 and laser welded.

[0079] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A thermal runaway prevention capsule, characterized in that: A capsule shell (1) is provided, wherein a thermal runaway prevention material (2) is arranged inside the capsule shell (1), and the material of the capsule shell (1) is polyethylene modified by salt and an organic compound; The thermal runaway prevention material (2) is red phosphorus; The salt is calcium carbonate, and the organic compound is stearic acid; The thermal runaway prevention capsule comprises the following steps: S1, preparing temperature-sensitive materials; S2, using the temperature-sensitive material to perform plastic deformation to produce the shape of the capsule shell (1), S3, placing thermal runaway prevention material (2) inside; S4, fastening the capsule shell (1) and raising the temperature to make the capsule airtight; The preparation method of the temperature sensitive material comprises the following steps: Step 1, heating the calcium carbonate in a water bath and then filtering it out; Step 2, mixing the filtered calcium carbonate and stearic acid in ethanol; Step 3: Dry the mixed calcium carbonate and stearic acid and add polyethylene.

2. The thermal runaway prevention capsule according to claim 1, characterized in that: In step 1, the water bath heating temperature is 65°C to 90°C.

3. The thermal runaway prevention capsule according to claim 2, characterized in that: In step 1, the water bath heating time is 10 to 20 minutes.

4. The thermal runaway prevention capsule according to claim 3, characterized in that: In step 2, the mass percentage of stearic acid is 3%.

5. A thermal runaway protection battery, using the thermal runaway protection capsule as claimed in claim 1, characterized in that: It comprises a shell (3), wherein an injection hole (4) is provided above the shell (3), and the thermal runaway prevention capsule is placed into the shell (3) through the injection hole (4).

6. A method for manufacturing a thermal runaway-proof battery as claimed in claim 5, characterized in that: The method comprises the following preparation steps: ① Prepare the bare battery cell, shell (3), top cover, bottom support plate, Mylar film, connecting piece, and thermal runaway protection capsule of the battery; ②Ultrasonic welding of the bare cell tabs and the connecting pieces; ③Laser weld the connecting piece with bare battery cells to the top cover; ④Hot-melt the bottom support plate and the Mylar film; ⑤Wrap the bare battery cell with Mylar film with a bottom support plate, and hot-melt the Mylar film with the lower plastic of the top cover; ⑥ Installing the sample melted in step ⑤ in the housing (3) and performing laser welding; ⑦ Carry out helium inspection, formation, volume separation and related inspection and activation; ⑧ Insert the thermal runaway prevention capsule into the battery through the injection hole (4) and seal it.

7. The method for manufacturing a thermal runaway-proof battery according to claim 6, characterized in that: The seal uses an anti-thermal runaway capsule to block the injection hole (4).

8. The method for manufacturing a thermal runaway-proof battery according to claim 7, characterized in that: After sealing in step ⑧, a metal sealing pin is placed above the injection hole (4) and laser welded.

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