Battery cell and battery pack

Abstract

This utility model relates to the field of battery cell technology, and discloses a battery cell and a battery pack. The battery cell mainly includes: a housing, an explosion-proof valve, and a protective patch. A through hole is provided on one side of the housing; the explosion-proof valve is disposed within the through hole; the protective patch is disposed on the side of the housing with the through hole, and has a clearance hole to avoid the explosion-proof valve. The melting point M of the protective patch is... P1 Above the melting point M of the shell P2 In the event of thermal runaway, the battery cell of this invention utilizes an explosion-proof valve to rapidly expel the gas and heat inside the cell. A protective patch with a higher melting point is added to the side of the casing where the explosion-proof valve is installed. This protective patch provides sufficient structural strength during thermal runaway, preventing damage to the casing from causing the thermal runaway to spread, thereby improving the safety and reliability of the battery cell.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to battery cells and battery packs. Background Technology

[0002] As a crucial component of new energy vehicles, the safety performance of new energy batteries is paramount. With increasing demands for driving range in new energy vehicles, the energy density of battery cells is constantly increasing, leading to a gradual decrease in the safety performance of these cells.

[0003] When a battery cell experiences thermal runaway, a large amount of heat is generated inside the cell in a short period of time, causing the internal pressure of the cell to rise continuously. This causes the explosion-proof valve to open, allowing the gas and heat inside the cell to escape through the explosion-proof valve, preventing the heat from accumulating inside the cell and causing the surrounding cells to fail.

[0004] Currently, the casing of battery cells is generally made of aluminum. When the battery cell experiences thermal runaway, the spray temperature at the explosion-proof valve port is high and can easily exceed the melting point of the aluminum casing, resulting in a significant reduction in the strength of the casing. The explosion-proof valve port is easily damaged due to high temperature, which can affect other components of the battery cell and ultimately cause thermal runaway to spread to surrounding battery cells, leading to battery cell failure. Utility Model Content

[0005] In view of this, the present invention provides a battery cell and battery pack to solve the problem that the strength of the battery cell casing is significantly reduced during thermal runaway, which leads to the easy propagation of thermal runaway and battery cell failure.

[0006] In a first aspect, this utility model provides a battery cell, comprising:

[0007] The casing has a through hole on one side;

[0008] An explosion-proof valve is disposed within the through hole;

[0009] A protective patch is disposed on the side of the housing where the through hole is located, and has a clearance hole to avoid the explosion-proof valve. The melting point M of the protective patch is... P1 The melting point M of the shell is higher than that of the shell. P2 .

[0010] Secondly, the present invention also provides a battery pack, comprising: at least one of the above-mentioned battery cells.

[0011] Beneficial effects: In the event of thermal runaway, the battery cell of the above technical solution uses an explosion-proof valve to quickly expel the gas and heat inside the battery cell. A protective patch with a higher melting point is added to the side of the casing where the explosion-proof valve is installed. The protective patch can provide sufficient structural strength in the event of thermal runaway, preventing damage to the casing from causing the thermal runaway to spread, thereby improving the safety and reliability of the battery cell. Attached Figure Description

[0012] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the structure of a battery cell according to an embodiment of the present utility model;

[0014] Figure 2 This is a schematic diagram of the structure of a battery cell from another angle according to an embodiment of the present invention;

[0015] Figure 3 This is a cross-sectional view of a battery cell according to an embodiment of the present utility model;

[0016] Figure 4 for Figure 3 A magnified view of a section at point A in the middle;

[0017] Figure 5 This is an exploded view of a battery cell according to an embodiment of the present utility model;

[0018] Figure 6 This is a schematic diagram of a protective patch for a battery cell according to an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures:

[0020] 1. Housing; 101. Through hole; 2. Explosion-proof valve; 3. Protective patch; 301. Clearance hole; 302. Flanged edge; 4. Pole group; 5. Cover plate assembly; 501. Pole post. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0022] In this embodiment of the invention, a "cell" refers to a single battery cell capable of independent charging and discharging. The components of a cell may include a positive electrode, a negative electrode, a separator, an electrolyte, and outer packaging for encapsulating the positive electrode, negative electrode, separator, and electrolyte. This embodiment of the invention does not impose any particular limitations on the type or shape of the cell; it can be a pouch cell, a cylindrical cell, a prismatic cell, or any other type of cell. The cell in this embodiment of the invention can be a lithium-ion cell, a potassium-ion cell, a sodium-ion cell, a lithium-sulfur cell, etc., with lithium-ion cells being particularly preferred. During the charging and discharging process, active ions repeatedly insert and extract between the positive and negative electrode plates. The electrolyte acts as a conductor of ions between the positive and negative electrode plates.

[0023] In this embodiment of the utility model, the "explosion-proof valve" refers to a structure that rapidly releases pressure when the internal pressure of the battery cell rises abnormally, preventing explosion or thermal runaway. It can be a mechanical explosion-proof valve or a composite explosion-proof valve.

[0024] In this embodiment of the invention, the "battery pack" is formed by electrically connecting a certain number of battery cells together and placing them in a frame to protect the battery cells from external impacts, heat, vibration, etc. The battery pack in this embodiment can be cylindrical, square, or any other arbitrary shape.

[0025] In this embodiment of the invention, several battery cells can be assembled together to form a battery pack. The battery pack contains one, two or more battery cells, the specific number of which depends on the application of the battery pack and the parameters of a single battery pack.

[0026] The following is combined Figures 1 to 6 The following describes embodiments of the present invention.

[0027] According to embodiments of the present invention, on the one hand, such as Figure 1 As shown, a battery cell is provided, mainly comprising: a housing 1, an explosion-proof valve 2, and a protective patch 3. A through hole 101 is provided on one side of the housing 1. The explosion-proof valve 2 is disposed within the through hole 101. The protective patch 3 is disposed on the side of the housing 1 with the through hole 101, and has a clearance hole 301 to avoid the explosion-proof valve 2. The melting point M of the protective patch 3 is... P1 The melting point M is higher than that of shell 1 P2 .

[0028] Therefore, the battery cell provided in this embodiment of the present invention, in the event of thermal runaway, utilizes the explosion-proof valve 2 to rapidly expel the gas and heat inside the battery cell. A protective patch 3 with a higher melting point is added to the side of the housing 1 where the explosion-proof valve 2 is installed. The protective patch 3 provides sufficient structural strength during thermal runaway, preventing damage to the housing 1 and the spread of thermal runaway, thereby improving the safety and reliability of the battery cell. Furthermore, the protective patch 3 also protects the housing 1 from external contamination. The protective patch 3 has an avoidance hole 301 to avoid the explosion-proof valve 2, ensuring that it does not affect the normal operation of the explosion-proof valve 2.

[0029] Specifically, at least one pole group 4 is provided inside the housing 1. The number of pole groups 4 can be selected as needed, such as one, two or more. The shapes of the through hole 101 and the clearance hole 301 need to correspond to the structural configuration of the explosion-proof valve 2. For example, if the explosion-proof valve 2 has a racetrack-shaped cross section, then both the through hole 101 and the clearance hole 301 are racetrack-shaped holes.

[0030] Of course, the explosion-proof valve 2 can also be selected with a circular cross section, a rectangular cross section, etc., as needed. The specific setting can be selected according to actual needs. This utility model embodiment does not impose too many restrictions on this.

[0031] It should be noted that this embodiment of the invention does not limit the fixed connection between the protective patch 3 and the housing 1, and any existing connection method can be selected as needed. For example, in applications requiring high strength, the protective patch 3 and the housing 1 can be welded together as a whole, resulting in a firm connection. In applications requiring light loads, sealing, or shock absorption, the protective patch 3 and the housing 1 can be fixed with an adhesive, such as epoxy resin, polyurethane, or acrylic structural adhesive.

[0032] Furthermore, the explosion-proof valve 2 of this embodiment can be selected to be installed on any side of the housing 1 as needed, and can be selected to be installed at any position on the side of the housing 1. Correspondingly, the protective patch 3 is provided on the same side of the housing 1 where the explosion-proof valve 2 is installed. For example, a through hole 101 is opened at the middle position of one side of the housing 1 along its length and the explosion-proof valve 2 is installed thereon, and the protective patch 3 is provided on the side of the housing 1 where the through hole 101 is provided along its length.

[0033] In one embodiment, such as Figure 4 and Figure 5 As shown, the protective patch 3 is fixed to the outer side of the housing 1 where the through hole 101 is located, and covers the outer side. Placing the protective patch 3 on the outer side of the housing 1 avoids the protective patch 3 occupying the internal space of the housing 1, preventing it from affecting the installation of the electrode assembly 4, and does not require modification of the structure of the housing 1 itself, making installation and use convenient. Completely covering the outer side of the housing 1 with the protective patch 3 can achieve comprehensive protection on one side of the housing 1, reducing the entry of moisture, dust, etc. into the interior of the housing 1, and also preventing the spread of thermal runaway.

[0034] Specifically, along the height direction, the projection of the protective patch 3 completely covers the projection of the side of the housing 1 with the through hole 101, that is, the projection of the side of the housing 1 with the through hole 101 falls entirely within the projection of the protective patch 3. (Height direction as follows) Figure 1 As indicated by arrow H in the diagram.

[0035] In one embodiment, such as Figure 1 and Figure 6 As shown, the protective patch 3 has a flange 302 extending along the periphery of the housing 1. The flange 302 on the periphery of the protective patch 3 can increase the contact area between the protective patch 3 and the housing 1, making the protective patch 3 more firmly fixed to the housing 1. Moreover, the flange 302 can distribute stress and reduce the risk of warping at the edge of the protective patch 3.

[0036] Furthermore, in one embodiment, the width of the flange 302 is 3mm-10mm. Specifically, the width of the flange 302 refers to the dimension of the flange 302 along the height direction. For example, the width of the flange 302 can be 3mm, 5mm, 7mm, 10mm, etc.

[0037] In other embodiments, the protective patch 3 can also be affixed between the electrode assembly 4 and the inner side of the housing 1 where the through hole 101 is provided (not shown in the figure). Specifically, the protective patch 3 can be fixed on the side of the electrode assembly 4 near the explosion-proof valve 2, and the fixing method can be adhesive bonding. Affixing the protective patch 3 between the electrode assembly 4 and the inner side of the housing 1 can directly protect the electrode assembly 4 and prevent the electrode assembly 4 from being damaged in the event of thermal runaway.

[0038] In one embodiment, such as Figure 2 and Figure 3 As shown, the housing 1 has an opening on one side along the first direction, and the battery cell also includes a cover plate assembly 5, which covers the opening and is connected to the housing 1.

[0039] Specifically, the cover plate assembly 5 is provided with a pole post 501, which is electrically connected to the electrode tab on the pole group 4 via a connecting piece. The first direction is also the height direction, such as... Figure 1 As indicated by arrow H. The cover assembly 5 can optionally be positioned on top of the housing 1.

[0040] Furthermore, the terminal 501 includes a positive terminal and a negative terminal, which are located at both ends of the cover assembly 5 along its length. The length direction of the cover assembly 5 is also the length direction of the housing 1, as shown below. Figure 1 As indicated by arrow L in the diagram. The width direction of the cover assembly 5 is also the width direction of the housing 1, as shown in the diagram. Figure 1 As indicated by the arrow W in the diagram.

[0041] Furthermore, in one embodiment, such as Figure 3As shown, the through hole 101 is opened on the side of the housing 1 away from the cover plate assembly 5, that is, the explosion-proof valve 2 is located at the bottom of the housing 1, and the protective patch 3 is attached to the side of the housing 1 away from the cover plate assembly 5.

[0042] When a battery cell experiences thermal runaway, the high-temperature ejected material inside typically rises. Placing the explosion-proof valve 2 at the bottom of the housing 1 prevents the ejected material from directly impacting the valve, ensuring that the valve opens and releases pressure under the set pressure, thus improving its operational stability. Furthermore, when the electrode assembly 4 expands, the top of the housing 1 deforms more significantly, while the bottom deforms less under pressure. Therefore, placing the explosion-proof valve 2 at the bottom of the housing 1 provides greater stability.

[0043] In other embodiments, the through hole 101 can also be optionally formed on the cover plate assembly 5, that is, the explosion-proof valve 2 is set on the cover plate assembly 5, located on the top of the housing 1, and the protective patch 3 is attached to the outer or inner surface of the cover plate assembly 5. By directly setting the explosion-proof valve 2 on the cover plate assembly 5, the pressure relief path is shorter and the pressure relief efficiency is higher, and there is no need to form a through hole 101 on the housing 1, reducing the risk of strength loss of the housing 1.

[0044] It should be noted that the material of the protective patch 3 is not limited in this embodiment of the utility model.

[0045] In one embodiment, the protective patch 3 comprises any one of a stainless steel plate, a titanium plate, or a nickel-based alloy plate. Stainless steel plates have a melting point of approximately 1400°C to 1450°C, strong corrosion resistance, and low operating costs; the melting point varies slightly depending on the specific composition of the stainless steel plate. Titanium plates have a melting point of approximately 1668°C, exhibiting high strength and a high melting point. Nickel-based alloy plates have a melting point of approximately 1350°C to 1450°C; similarly, the melting point varies slightly depending on the specific composition of the nickel-based alloy plate. Nickel-based alloy plates possess high strength at high temperatures and are resistant to oxidation and corrosion, making them suitable for extreme environments.

[0046] In one embodiment, the melting point M of the protective patch 3 is... P1 The spray temperature is higher than that of the explosion-proof valve 2 during thermal runaway of the battery cell, which can ensure that the protective patch 3 has sufficient strength when the battery cell is thermally runaway, thereby reducing the risk of thermal runaway propagation and further improving the safety and reliability of the battery cell.

[0047] It should be noted that this embodiment of the utility model does not limit the material of the shell 1, and any existing material can be selected as needed.

[0048] For example, the housing 1 is made of aluminum, and the melting point M of the housing 1 is... P2 The temperature is approximately 660℃. Protective patch 3 is made of stainless steel plate, and the melting point of protective patch 3 is M. P1The temperature is approximately 1400℃. The spray temperature of the explosion-proof valve 2 during thermal runaway of the battery cell is approximately 300℃ to 900℃. During thermal runaway of the battery cell, the structural strength of the housing 1 will decrease significantly, but the melting point of the protective patch 3 is much higher than the spray temperature. Therefore, the structural strength of the protective patch 3 is still relatively high, and it can replace the housing 1 to provide effective support and protection.

[0049] According to an embodiment of the present invention, another aspect provides a battery pack, comprising: at least one battery cell.

[0050] Therefore, the battery pack provided in this embodiment utilizes an explosion-proof valve 2 to rapidly expel gas and heat from the battery cell when thermal runaway occurs. A protective patch 3 with a higher melting point is added to the side of the casing 1 where the explosion-proof valve 2 is installed. The protective patch 3 provides sufficient structural strength during thermal runaway, preventing damage to the casing 1 and the spread of thermal runaway, thus improving the safety and reliability of the battery cell. Furthermore, the protective patch 3 protects the casing 1 from external contamination. The protective patch 3 has an avoidance hole 301 to allow the explosion-proof valve 2 to pass, ensuring its normal operation.

[0051] To achieve the basic functions of the battery pack, the battery pack in this embodiment may also include other necessary modules or components, such as a thermal management system and a control system. It should be noted that any suitable existing structure can be selected from the other necessary modules or components included in the battery pack. To clearly and concisely illustrate the technical solution provided in this embodiment, the above-mentioned parts will not be repeated here, and the accompanying drawings have also been simplified accordingly. However, it should be understood that the scope of this utility model is not limited as a result.

[0052] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that, include: The housing (1) has a through hole (101) on one side; An explosion-proof valve (2) is disposed in the through hole (101); A protective patch (3) is provided on the side of the housing (1) where the through hole (101) is located, and a clearance hole (301) is provided to avoid the explosion-proof valve (2). The melting point M of the protective patch (3) is... P1 The melting point M of the shell (1) is higher than that of the shell. P2 .

2. The battery cell according to claim 1, characterized in that, The protective patch (3) is fixed to the outer side of the housing (1) where the through hole (101) is located, and covers the outer side.

3. The battery cell according to claim 2, characterized in that, The protective patch (3) has a flange (302) extending along the periphery of the housing (1).

4. The battery cell according to claim 3, characterized in that, The width of the flange (302) is 3mm-10mm.

5. The battery cell according to claim 1, characterized in that, The housing (1) is provided with an electrode assembly (4), and the protective patch (3) is attached between the electrode assembly (4) and the inner side of the housing (1) where the through hole (101) is located.

6. The battery cell according to claim 1, characterized in that, The housing (1) has an opening on one side along the first direction, and the battery cell also includes a cover plate assembly (5), which covers the opening and is connected to the housing (1).

7. The battery cell according to claim 6, characterized in that, The through hole (101) is opened on the side of the housing (1) away from the cover plate assembly (5), and the protective patch (3) is attached to the side of the housing (1) away from the cover plate assembly (5).

8. The battery cell according to claim 6, characterized in that, The through hole (101) is formed on the cover plate assembly (5), and the protective patch (3) is attached to the surface of the cover plate assembly (5).

9. The battery cell according to any one of claims 1 to 8, characterized in that, The protective patch (3) includes any one of stainless steel plate, titanium plate, and nickel-based alloy plate.

10. The battery cell according to any one of claims 1 to 8, characterized in that, The melting point M of the protective patch (3) P1 The temperature is higher than the injection temperature of the explosion-proof valve (2) when the battery cell is thermally runaway.

11. A battery pack, characterized in that, include: At least one battery cell according to any one of claims 1 to 10.

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