Blade battery cell, battery module and vehicle

Abstract

The utility model relates to a blade battery cell, a battery module and a vehicle, the blade battery cell comprises a battery cell assembly, an anti-explosion valve and a gas guide part, the anti-explosion valve is arranged at one end of the battery cell assembly; a notch is formed in one end, close to the anti-explosion valve, of the battery cell assembly; the air guide part abuts against the end face of the notch, and the second end of the air guide part communicates with the anti-explosion valve. The gap is formed in one corner of the battery cell assembly of the blade battery cell, the gas guide part is arranged at the gap and is communicated with the anti-explosion valve, and during thermal runaway, the gas guide part directly introduces gas generated by the battery cell into the anti-explosion valve, so that the anti-explosion valve is broken to release the gas and pressure, the time for the gas to reach the anti-explosion valve is shortened, and the battery cell is prevented from exploding.

Description

Technical Field

[0001] This utility model relates to the technical field of new energy batteries, and in particular to a blade battery cell, battery module and vehicle. Background Technology

[0002] Blade cells are a new type of lithium battery that adopts a module-less structural design, directly integrating the cells into the battery pack. This improves the battery's volume utilization and energy density. Due to their excellent needle penetration safety and high assembly utilization, they are widely used in lithium-ion battery packs for passenger vehicles. A cell explosion-proof valve is a safety device that monitors internal pressure changes and releases excessive pressure to prevent cell explosion. The explosion-proof valve of a blade cell is generally located on the cover plate of the positive or negative electrode. Because blade cells are relatively long (generally 400–1000 mm) and thin (generally 13–26 mm), the aluminum shell wall is also relatively thin (generally 0.3–0.5 mm). The weld is located on the long, narrow side of the aluminum shell. During thermal runaway of a blade cell, there is a high probability that the aluminum shell weld will crack. The main reason is that the explosion-proof valve is located at one end of the cover plate. During thermal runaway, a large amount of gas is generated in a short time, and the gas transmission path is too long, preventing the explosion-proof valve from rupturing and releasing the gas and pressure quickly.

[0003] Existing methods for improving the release of gas and pressure in explosion-proof valves include adjusting electrolyte additives to reduce the gas generation rate, reducing the width / height of the electrode core, and increasing the gas passage between the electrode core and the shell. However, these methods still cannot quickly guide and export the gas generated in the electrode core to the explosion-proof valve, and the explosion-proof valve requires a long rupture time. Utility Model Content

[0004] To address the technical problem of the aluminum casing cracking caused by the inability to release gas in a short time during thermal runaway of the blade battery cell, this utility model provides a blade battery cell, a battery module, and a vehicle.

[0005] To achieve the above objectives, this utility model provides a blade battery cell, including a battery cell assembly, an explosion-proof valve, and a gas guide. The explosion-proof valve is disposed at one end of the battery cell assembly; a notch is provided at one end of the battery cell assembly near the explosion-proof valve; the gas guide abuts against the end face of the notch, and a second end of the gas guide communicates with the explosion-proof valve.

[0006] Furthermore, the battery cell assembly includes an electrode body and a separator. There are multiple electrode bodies, and the separators are spaced apart between the multiple electrode bodies. One end of the electrode body is provided with the notch, and the separator is provided with a cut portion, which is located at a position corresponding to the notch.

[0007] Furthermore, the end face of the first end of the air guide is greater than or equal to the end face of the notch.

[0008] Furthermore, the air guide includes an inclined portion and an extension portion. The inclined portion abuts against the battery cell assembly, and the extension portion extends horizontally out of the notch and communicates with the explosion-proof valve.

[0009] Furthermore, the end of the cut-out portion away from the explosion-proof valve is separated from the diaphragm, and the cut-out portion is fixed to the outer wall of the gas guide portion.

[0010] Furthermore, the end face of the notch is an inclined surface that slopes to the side along the top surface of the cell assembly, and the end face of the first end of the air guide portion is adapted to the end face of the notch.

[0011] Furthermore, it also includes a spacer ring and a cover plate, the explosion-proof valve is disposed on the cover plate, the spacer ring is disposed between the battery cell assembly and the cover plate, the spacer ring has an opening, and the second end of the gas guide portion passes through the opening and abuts against the explosion-proof valve.

[0012] Furthermore, it also includes an insulating film, which is connected to the cover plate and the spacer ring, and covers the battery cell assembly and the air guide portion. The insulating film connects and fixes the spacer ring, the cover plate, the air guide portion and the battery cell assembly.

[0013] Another objective of this embodiment is to provide a battery module having the aforementioned blade cell.

[0014] Another objective of this embodiment is to provide a vehicle equipped with the aforementioned blade cell or battery module.

[0015] The above-mentioned technical solution of this utility model has the following advantages compared with the prior art:

[0016] (1) A notch is made in one corner of the cell assembly of the blade cell, and the gas guide is set at the notch. The gas guide is connected to the explosion-proof valve. In the event of thermal runaway, the gas guide directly introduces the gas generated by the cell into the explosion-proof valve, causing the explosion-proof valve to rupture and release gas and pressure, shortening the time for the gas to reach the explosion-proof valve, and preventing the cell from exploding.

[0017] (2) The gas guide is placed between multiple diaphragms, and the diaphragms are fixed to the outer wall of the gas guide to prevent the diaphragms from melting due to temperature rise and blocking the inside of the gas guide, thus preventing the gas from being discharged smoothly.

[0018] (3) The first end face of the gas guide, the notch and the contact surface of the electrode body and the cross-section of the cut are adapted to each other, which facilitates the installation of the gas guide. In addition, by setting a spacer with an opening at one end of the cell assembly, the gas guide is extended to the opening of the spacer and connected to the cover plate with an explosion-proof valve, thus optimizing the gas exhaust channel of the cell. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is an exploded view of the various components of the blade battery cell of this utility model;

[0021] Figure 2 This is a schematic diagram of the positive electrode sheet of this utility model;

[0022] Figure 3 This is a schematic diagram of the negative electrode sheet of this utility model;

[0023] Figure 4 This is a schematic diagram of a battery cell assembly with a cutout portion according to this utility model;

[0024] Figure 5 This is a schematic diagram of the air guide section of this utility model after it has been inserted into the battery cell assembly;

[0025] Figure 6 This is a perspective view of the air guide section of this utility model after it has been inserted into the battery cell assembly;

[0026] Figure 7 This is a schematic diagram of the air guide section of this utility model;

[0027] Figure 8 This is a schematic diagram of the battery cell assembly after the air guide and diaphragm are thermally melted according to this utility model;

[0028] Figure 9 This is a three-dimensional view of the battery cell assembly after the air guide and diaphragm are thermally melted according to this utility model;

[0029] Figure 10 This is a schematic diagram of the cover plate of this utility model;

[0030] Figure 11 This is a schematic diagram of the spacer ring of this utility model.

[0031] Explanation of reference numerals in the accompanying drawings: Cell assembly - 1; Electrode body - 11; Diaphragm - 12; Explosion-proof valve - 2; Gas guide - 3; Notch - 4; Cut-out - 5; Spacer - 6; Opening - 61; Cover plate - 7; Insulating film - 8. Detailed Implementation

[0032] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0033] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0034] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments.

[0035] This utility model is described in detail with reference to the schematic diagrams. When describing the embodiments of this utility model, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, deviating from the general scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this utility model. In actual manufacturing, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0036] Furthermore, in the description of this utility model, it should be noted that the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0037] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" in this utility model should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integrated connections; similarly, they can refer to mechanical connections, electrical connections, or direct connections, or indirect connections through an intermediate medium, or internal connections between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0038] Example 1

[0039] like Figures 1-11 As shown in the figure, the blade battery cell provided by this utility model embodiment includes a battery cell assembly 1, an explosion-proof valve 2, and a gas guide 3. The explosion-proof valve 2 is located at one end of the battery cell assembly 1. In the event of thermal runaway, the battery cell assembly 1 generates gas, which is quickly discharged to the explosion-proof valve 2 through the gas guide 3, causing the explosion-proof valve 2 to rupture rapidly under pressure. This reduces the risk of weld cracking of the battery cell shell due to thermal runaway and reduces losses. A notch 4 is provided at one end of the battery cell assembly 1 near the explosion-proof valve 2. The first end of the gas guide 3 abuts against the end face of the notch 4, and the second end of the gas guide 3 is connected to the explosion-proof valve 2. The gas guide 3 provides a gas guide channel between the battery cell assembly 1 and the explosion-proof valve 2, guiding a large amount of gas generated by the battery cell to flow to the explosion-proof valve 2, causing the explosion-proof valve 2 to rupture rapidly under pressure. This facilitates the rapid release of gas and pressure during thermal runaway and shortens the time from the start of thermal runaway to the explosion-proof valve rupture.

[0040] It should be noted that, referring to Figure 7 The air guide section 3 can use an aerogel ring. The main materials of the aerogel ring include, but are not limited to, pre-oxidized fiber aerogel felt with silica aerogel as the base material, flexible insulation felt with aerogel as the base material with wet glass fiber felt, and insulation sheet with silica aerogel as the base material. It has the characteristics of being lightweight and resistant to high temperature. As a preferred option, the cross-sectional shape of the air guide section 3 is set to be circular or racetrack-shaped, and its thickness is set between 0.2mm and 2mm.

[0041] In one embodiment, the battery cell assembly 1 includes an electrode body 11 and a diaphragm 12. There are multiple electrode bodies 11, and the diaphragms 12 are spaced apart between the multiple electrode bodies 11. A notch 4 is provided at one end of the electrode body 11. The notch 4 is located at one end of the electrode body 11 near the explosion-proof valve 2. A cut portion 5 is provided on the diaphragm 12 at a position adapted to the notch 4. The cut portion 5 of the diaphragm 12 allows the diaphragm 12 to extend to both sides as the gas guide 3 extends into the notch 4, so that the gas guide 3 can abut against the notch 4.

[0042] It should be noted that, referring to Figures 2-3 The electrode body 11 includes a positive electrode and a negative electrode. Each of the positive and negative electrode has a tab at one end and a notch 4 at one end. When stacking the electrodes, the notches 4 of the positive and negative electrode are positioned correspondingly, and the tabs are positioned at opposite ends. Furthermore, a separator 12 is provided between each positive and negative electrode.

[0043] In one embodiment, the end face of the first end of the gas guide 3 is greater than or equal to the end face of the notch 4, so that the gas generated by the battery cell assembly 1 can be introduced into the explosion-proof valve 2 through the gas guide 3, further shortening the gas transmission time.

[0044] In one embodiment, the air guide 3 includes an inclined portion 31 and an extension portion 32. The inclined portion 31 abuts against the battery cell assembly 1, and the end face of the inclined portion 31 abuts against the notch 4, ensuring the air guiding effect of the air guide 3. The extension portion 32 extends horizontally out of the notch 4 and communicates with the explosion-proof valve 2. The extension portion 32 leaves an installation space between the battery cell assembly 1 and the explosion-proof valve 2, and can also be used to position the air guide 3 to prevent the air guide 3 from falling off the notch 4.

[0045] In one embodiment, refer to Figure 8 and 9 One end of the cut portion 5 is separated from the diaphragm 12, and the other end of the cut portion 5 is connected to the diaphragm 12, so that the air guide portion 3 abuts against the notch 4. The second end of the air guide portion 3 is connected to the explosion-proof valve 2. Since one end of the cut portion 5 is separated from the diaphragm 12, when the air guide portion 3 is inserted into the notch 4, the diaphragm 12 with the cut portion 5 separates from both sides of the air guide portion 3, so that the air guide portion 3 is placed between the multiple layers of diaphragms 12. The cut portion 5 is fixedly connected to the outer wall of the air guide portion 3, ensuring that the diaphragm 12 is placed outside the air guide portion 3. In this embodiment, the diaphragm 12 is thermally fused to the outer wall of the air guide portion 3. Since the temperature during thermal runaway of the battery cell is between 400 and 700°C, and the diaphragm 12 will thermally shrink when the temperature is between 110 and 150°C, the diaphragm 12 is fixed to the outer wall of the air guide portion 3 to further prevent the diaphragm 12 from blocking the air guide portion 3 after thermal shrinkage, thus ensuring the smooth flow of the air guide portion 3.

[0046] In one embodiment, refer to Figure 5 and 6 The end face of the notch 4 is an inclined surface, which is an inclined surface that is inclined to the side along the top surface of the cell assembly 1. The notch 4 is inclined to the side closer to the explosion-proof valve 2. The end face of the first end of the gas guide 3 and the notch 4 are adapted to each other. On the one hand, it ensures that the end face of the gas guide 3 is in direct contact with the electrode body 11. On the other hand, it maximizes the size of the air inlet of the gas guide 3, further accelerating the time for the gas generated by the electrode body 11 to flow to the explosion-proof valve 2, and accelerating the opening time of the explosion-proof valve 2. As a preferred option, the notch 4 is set at the corner of the cell assembly 1 and is a triangular structure. The contact surface between the notch 4 and the electrode body 11 is an inclined surface, which can increase the size of the contact surface between the notch 4 and the electrode body 11. The inclined surface of the notch 4 is inclined towards the explosion-proof valve 2. The notch 4 provides a gas guide channel for the gas guide 3 to connect the electrode body 11 and the explosion-proof valve 2.

[0047] In one embodiment, refer to Figure 1 and 10The blade battery cell also includes a spacer ring 6 and a cover plate 7. The cover plate 7 is located at the end of the battery cell assembly 1. The cover plate 7 is used to isolate and protect the battery cell, preventing the battery cell assembly 1 from being contaminated and corroded by the outside world. The explosion-proof valve 2 is located on the cover plate 7 to protect the internal structure of the battery cell assembly 1 and ensure the normal operation of the battery cell assembly 1. One side of the spacer ring 6 is connected to the battery cell assembly 1, and the other side is connected to the cover plate 7. It is located between the battery cell assembly 1 and the cover plate 7 to ensure the sealing between the cover plate 7 and the battery cell assembly 1. An opening 61 is opened at the upper part of the spacer ring 6. The second end of the air guide 3 passes through the opening 61 and abuts against the explosion-proof valve 2 to ensure the smooth flow between the air guide 3 and the explosion-proof valve 2. The opening 61 provides support for the air guide 3 to prevent the air guide 3 from falling off from the notch 4.

[0048] It should be noted that during cell installation, a protruding lower plastic part is provided on the cover plate 7, and a groove is provided on the spacer 6 to cooperate with the lower plastic part. The spacer 6 and the cover plate 7 are positioned by the lower plastic part and the groove. Furthermore, a tab is provided at one end of the positive and negative electrode plates in the electrode body 11. The cover plate 7 can be welded to the tab. When the cover plate 7 is folded 90° for assembly, the gas guide 3 will pass through the opening 61 and contact the explosion-proof valve 2 to ensure smooth gas flow.

[0049] In one embodiment, refer to Figure 1 The blade battery cell also includes an insulating film 8, which is connected to the cover plate 7 and the spacer 6 and surrounds the battery cell assembly 1. The insulating film 8 connects and fixes the cover plate 7, the spacer 6 and the battery cell assembly 1. The insulating film 8 can use an inner insulating film, Mylar film. In the embodiment, the insulating film 8 is fixed to the cover plate 7 and the spacer 6 by heat fusion and surrounds the battery cell assembly 1. The first end of the vent 3 abuts against the notch 4 and the second end of the vent 3 abuts against the explosion-proof valve 2. Therefore, when the cover plate 7, the spacer 6 and the battery cell assembly 1 are fixed, the vent 3 can be fixed.

[0050] It should be noted that the blade cell also includes a housing, which surrounds the insulating film 8 and isolates the cell assembly 1 from the housing. The housing is made of aluminum, which is low in cost and light in weight, and can protect the inside of the cell.

[0051] The working principle of the blade battery cell provided in this embodiment is as follows: Electrode bodies 11 and diaphragms 12 are alternately stacked and hot-pressed to form a battery cell assembly 1. The notches 4 of the electrode bodies 11 correspond to each other. After stacking, a cut 5 is made on the diaphragm 12 along the notch 4. After cutting, a gas guide 3 is inserted into the notch 4 on the side, and the diaphragm 12 is hot-melted to the outer wall of the gas guide 3. A spacer ring 6 and a cover plate 7 are placed at both ends of the battery cell assembly 1. An insulating film 8 is then used to fix the spacer ring 6 and the cover plate 7 by hot-melting, thus wrapping the battery cell assembly 1. Through welding, casing assembly, and other processes, a finished battery cell is produced. The second end of the gas guide 3 is connected to an explosion-proof valve. When the battery cell experiences thermal runaway, the gas generated by the battery cell assembly 1 flows into the explosion-proof valve 2 through the gas guide 3, opening the explosion-proof valve 2 and venting the gas. In this embodiment, the blade battery cell with the gas guide 3 and the ordinary blade battery cell are respectively equipped with external heating plates and clamps, and thermal runaway experiments are conducted under the same conditions. The explosion-proof valve of the blade battery cell with the gas guide opens 4 to 10 seconds earlier than that of the ordinary blade battery cell, allowing the gas to be vented normally. Furthermore, there are no cracks at the narrow edge weld of the aluminum shell, and the battery cell does not catch fire or explode, thus avoiding weld cracking and effectively improving the safety of the battery cell. When the blade battery cell with the gas guide is subjected to thermal diffusion test, no thermal runaway problem occurs between adjacent battery cells.

[0052] Example 2

[0053] Unlike the above embodiments, this embodiment provides a battery module in which the blade cell is provided. This avoids the fire and explosion of a single cell in the battery under thermal runaway, thus preventing safety issues. It also prevents adjacent cells in the module from experiencing thermal runaway simultaneously, ensuring the normal operation of the battery module and improving operational safety.

[0054] Example 3

[0055] Unlike the above embodiments, this embodiment provides a vehicle equipped with the aforementioned blade battery cell or battery module, which can ensure the normal operation of the vehicle under high temperature conditions and improve the safety of vehicle operation.

[0056] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A blade battery cell, characterized in that, It includes a battery cell assembly (1), an explosion-proof valve (2), and a gas guide (3), wherein the explosion-proof valve (2) is disposed at one end of the battery cell assembly (1); The battery cell assembly (1) has a notch (4) at one end near the explosion-proof valve (2); The gas guide (3) abuts against the end face of the notch (4), and the second end of the gas guide (3) is connected to the explosion-proof valve (2).

2. The blade battery cell according to claim 1, characterized in that, The battery cell assembly (1) includes an electrode body (11) and a separator (12). There are multiple electrode bodies (11), and the separators (12) are spaced apart between the multiple electrode bodies (11). One end of the electrode body (11) is provided with the notch (4), and the separator (12) is provided with a cut (5), which is located at a position corresponding to the notch (4).

3. The blade battery cell according to claim 2, characterized in that, The end face of the first end of the air guide (3) is greater than or equal to the end face of the notch (4).

4. The blade battery cell according to claim 1, characterized in that, The air guide (3) includes an inclined part (31) and an extension part (32). The inclined part (31) abuts against the battery cell assembly (1), and the extension part (32) extends horizontally out of the notch (4) and communicates with the explosion-proof valve (2).

5. The blade battery cell according to claim 2, characterized in that, The cut portion (5) is separated from the diaphragm (12) at one end away from the explosion-proof valve (2), and the cut portion (5) is fixed to the outer wall of the gas guide portion (3).

6. The blade cell according to claim 1, characterized in that, The end face of the notch (4) is an inclined surface that is inclined to the side along the top surface of the battery cell assembly (1), and the end face of the first end of the air guide (3) is adapted to the end face of the notch (4).

7. The blade battery cell according to claim 1, characterized in that, It also includes a spacer ring (6) and a cover plate (7). The explosion-proof valve (2) is disposed on the cover plate (7). The spacer ring (6) is disposed between the battery cell assembly (1) and the cover plate (7). An opening (61) is opened on the spacer ring (6). The second end of the gas guide (3) passes through the opening (61) and abuts against the explosion-proof valve (2).

8. The blade battery cell according to claim 7, characterized in that, It also includes an insulating film (8), which is connected to the cover plate (7) and the spacer (6) and covers the battery cell assembly (1) and the air guide (3). The insulating film (8) connects and fixes the spacer (6), the cover plate (7), the air guide (3) and the battery cell assembly (1).

9. A battery module, characterized in that, Includes the blade battery cell as described in any one of claims 1 to 8.

10. A vehicle, characterized in that, Includes the blade cell as described in any one of claims 1 to 8 or the battery module as described in claim 9.

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