Battery cell gas collecting device and battery

Abstract

The embodiment of the utility model discloses a cell gas collection device and a battery. The cell gas collection device comprises a gas storage main body with a gas storage cavity; and the one-way gas guide device is arranged in the gas storage main body, the one-way gas guide device comprises a movable mechanism and a sealing piece, and the movable mechanism moves relative to the sealing piece to allow or prevent gas from entering the gas storage cavity. According to the embodiment of the invention, gas in the battery cell is stored, so that analysis of reasons for opening the valve of the battery cell is facilitated.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a cell gas collection device and a battery. Background Art

[0002] Currently, new energy vehicles generally use battery packs as power sources for driving. Due to various reasons, during the use of battery packs, the problem of cell failure will inevitably occur. When a cell fails, there are various situations in its own performance, and one of the situations is that the cell valve opens.

[0003] In order to determine the real cause of the cell valve opening, the gas inside the shell of the opened-valve cell is usually detected and analyzed. During the actual detection and analysis process, it is found that once the cell valve opens, the gas inside its shell has already diffused to the outside, and at the same time, the air outside the cell shell will also enter the inside of the cell shell. Eventually, the mixed air greatly reduces the accuracy of the detection and analysis of the cause of the cell valve opening.

[0004] Regarding the above technical problems, no clear solution has been found in the current industry. Utility Model Content

[0005] The present application aims to at least solve one of the technical problems existing in the prior art. For this reason, the present application provides a cell gas collection device and a battery to store the gas inside the cell, thereby helping to analyze the cause of the cell valve opening.

[0006] In a first aspect, the present application provides a cell gas collection device, including:

[0007] A gas storage main body having a gas storage cavity;

[0008] A one-way gas guiding device disposed inside the gas storage main body, the one-way gas guiding device including a moving mechanism and a sealing member, the moving mechanism moving relative to the sealing member to allow or block gas from entering the gas storage cavity.

[0009] In an embodiment of the above cell gas collection device,

[0010] The moving mechanism includes a moving member and a spring, the spring supporting the moving member so that it abuts against the sealing member at an initial position to block gas from entering the gas storage cavity;

[0011] When the external air pressure is greater than the air pressure inside the gas storage cavity, the moving member compresses the spring to form a gap with the sealing member to allow gas to enter the gas storage cavity.

[0012] In an embodiment of the above cell gas collection device,

[0013] The surface of the movable part in contact with the seal is an arc surface or a conical surface.

[0014] In one embodiment of the above-mentioned battery cell gas collection device,

[0015] The seal includes a seal seat and a sealing ring. The seal seat has a gas passage communicating the outside with the gas storage cavity, and the sealing ring is arranged between the seal seat and the movable part.

[0016] In one embodiment of the above-mentioned battery cell gas collection device,

[0017] A clamping groove is provided on the seal seat, and the sealing ring is installed on the seal seat through the clamping groove.

[0018] In one embodiment of the above-mentioned battery cell gas collection device,

[0019] One end of the gas passage relative to the movable part is funnel-shaped.

[0020] In one embodiment of the above-mentioned battery cell gas collection device,

[0021] The gas storage main body further has an installation cavity communicating with the gas storage cavity, and the one-way gas guiding device is installed in the installation cavity.

[0022] In one embodiment of the above-mentioned battery cell gas collection device,

[0023] A support edge is provided between the installation cavity and the gas storage cavity, and the moving mechanism is arranged on the support edge.

[0024] In a second aspect, the present application provides a battery, including a housing, a battery cell installed in the housing, and the battery cell gas collection device according to any one of the first aspect; the battery cell gas collection device is arranged in the space between the battery cell and the housing.

[0025] In one embodiment of the above-mentioned battery,

[0026] The height of the gas storage main body is less than or equal to that of the battery cell, and the cross-sectional size and shape of the gas storage main body fit the space between the battery cell and the housing.

[0027] One or more of the above embodiments of the present application have at least one or more of the following beneficial effects:

[0028] In this application, by setting a one-way gas guiding valve structure in the gas storage main body, and controlling the movement of the movable mechanism relative to the seal to allow or block the gas from entering the gas storage cavity, the gas can be collected into the gas storage cavity before the cell valve is opened, the gas inside the cell can be stored, and the gas in the gas storage cavity will not overflow after the cell valve is opened, nor will external air enter. Analyzing the gas components in the gas collection device can help analyze the chemical reactions occurring inside the cell before the valve opening fails, thereby determining the cause of the cell valve opening, providing an improvement direction for the cell enterprise to improve such valve opening failures in the future. The overall structure is simple. Without reducing the volumetric energy density of the cell, the gas storage function of the cell is increased, effectively storing the gas at the last moment before the failure inside the cell, and providing an internal gas sample for the analysis of the valve opening failure.

[0029] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Referring to the accompanying drawings, the disclosure of the present application will become more understandable. It is easy for those skilled in the art to understand that these drawings are only for illustrative purposes and are not intended to limit the protection scope of the present application. In addition, similar numbers in the drawings are used to represent similar components, where:

[0031] Figure 1 is a schematic diagram of the external structure of the cell gas collection device in an embodiment of the present application;

[0032] Figure 2 is a schematic sectional structure diagram of the cell gas collection device in an embodiment of the present application;

[0033] Figure 3 is a schematic diagram of the specific sectional structure of the cell gas collection device in an embodiment of the present application;

[0034] Figure 4 is a schematic diagram of the seal seat structure of the cell gas collection device in an embodiment of the present application;

[0035] Figure 5 is a schematic diagram of the gas storage main body structure of the cell gas collection device in an embodiment of the present application;

[0036] Figure 6 is a schematic diagram of the battery structure in an embodiment of the present application;

[0037] Figure 7 is a schematic diagram of the partial structure of the battery housing wall with a groove in an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] Some embodiments of the present application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present application and are not intended to limit the protection scope of the present application.

[0039] It should be noted that in the description of the present application, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the accompanying drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0040] In addition, it should also be noted that in the description of the present application, unless otherwise clearly specified and limited, the terms "installation", "setting", "connection" 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 directly connected, or indirectly connected through an intermediate medium, and can also be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0041] As described in the background art, currently, for the failure of the cell valve opening, the external dispersion of gas, and the air mixed in, the accuracy of the detection and analysis of the reasons for the cell valve opening is greatly reduced, and there is no clear solution. Based on this, the present application proposes a cell gas collection device to store the gas inside the cell, thereby helping to analyze the reasons for the cell valve opening.

[0042] Refer to the attached Figure 1 and Figure 2 , Figure 1 is a schematic external structure diagram of a cell gas collection device according to an embodiment of the present application, Figure 2 is a schematic cross-sectional structure diagram of a cell gas collection device according to an embodiment of the present application. As Figure 1 and Figure 2As shown, in one or more embodiments, the cell gas collection device of the present application includes a gas storage main body 10 having a gas storage cavity 11 and a one-way gas guiding device 20. The one-way gas guiding device 20 is arranged inside the gas storage main body 10. The one-way gas guiding device 20 includes a moving mechanism 21 and a seal 22. The moving mechanism 21 moves relative to the seal 22 to allow or block gas from entering the gas storage cavity 11. The purpose of the present application is to set a one-way gas guiding valve device 20 in the gas storage main body 10. By controlling the movement of the moving mechanism 21 relative to the seal 22 to allow or block gas from entering the gas storage cavity 11, gas can be collected into the gas storage cavity 11 before the cell valve is opened, and the gas inside the cell can be stored. And because the one-way gas guiding valve device 20 conducts air intake in one direction and will close after intake, therefore, the gas in the gas storage cavity 11 will not overflow after the cell valve is opened, and external air will not enter. The key structure of the entire cell gas collection device lies in the one-way gas guiding valve device 20. When the external air pressure is greater than the internal air pressure of the collection device, the moving mechanism 21 moves in a direction away from the seal 22 to generate a gap to allow gas to enter the gas storage cavity 11, that is, gas enters from the outside to the inside; on the contrary, when the external air pressure is lower than the internal air pressure of the collection device, the moving mechanism 21 moves closer to the seal 22 until they abut to block gas from entering the gas storage cavity 11, and the gas inside the collection device cannot flow to the outside. Analyzing the gas composition in the gas collection device can help analyze the chemical reactions that occur inside before the cell valve opening fails, and then determine the cause of the cell valve opening, providing an improvement direction for the cell enterprise to improve such valve opening failures in the future. The overall structure is simple. Without reducing the volume energy density of the cell, the gas storage function of the cell is increased, effectively storing the gas at the last moment before the cell fails, and providing an internal gas sample for the analysis of valve opening failure.

[0043] In one embodiment, as Figure 3As shown, the movable mechanism 21 includes a movable member 212 and a spring 211. The spring 211 supports the movable member 212 so that it abuts against the seal 22 at the initial position to block the gas from entering the gas storage chamber 11. When the external air pressure is greater than the air pressure inside the gas storage chamber 11, the movable member 212 compresses the spring 211 to generate a gap with the seal 22 to allow the gas to enter the gas storage chamber 11. In this embodiment, the movable mechanism 21 of the one-way air guiding valve device 20 is specifically composed of a movable member 212 and a spring 211. Its working principle is that when the external air pressure of the battery cell gas collection device is greater than the internal air pressure, the external high-pressure gas pushes the movable member 212 to slightly compress the spring 211. By using the performance of the spring 211 being compressed under force, a gap is generated between the movable member 212 and the seal 22, and the external high-pressure gas enters the inside of the battery cell gas collection device, that is, the gas storage chamber 11. When the internal and external pressures reach equilibrium, the gas stops flowing. Therefore, before the battery cell valve opens, the continuously rising internal pressure will cause the gas to continuously enter the gas storage chamber 11. Once the battery cell valve opens, the internal air pressure of the battery cell drops instantaneously. For the battery cell gas collection device, its internal and external pressure difference expands instantaneously, and the high-pressure gas inside the battery cell gas collection device instantly pushes the movable member 212 against the seal 22, and the internal gas cannot escape outward. Thus, the battery cell gas collection device can retain the gas sample at the last moment before the battery cell valve opens. Among them, the function of the spring 211 is not only to generate a gap between the movable member 212 and the seal 22 by using its performance of being compressed under force, but also to support the movable member 212 to ensure that the movable member 212 is close to the seal 22, and the degree of fitting is achieved through the compression amount of the spring 211.

[0044] In a possible implementation manner, the surface of the movable member 212 in contact with the seal 22 is an arc surface or a conical surface. Compared with a plane, the arc surface and the conical surface can ensure the degree of fitting with the seal 22 and improve the sealing performance. Further, the movable member 212 can be a ball. The ball can not only maintain the degree of fitting with the seal 22, effectively prevent gas from overflowing, but also roll smoothly and conveniently in the channel, which is beneficial to smoothly and effectively compress the spring 211 when the gas enters.

[0045] In a possible implementation manner, the material of the movable member 212 is PE or other polymers resistant to electrolyte. The characteristic is that it is lighter than the metal material to reduce the vibration of the movable member 212 itself during the vibration of the vehicle and ensure the contact between the movable member 212 and the seal 22.

[0046] In one embodiment, as Figure 3 and Figure 4As shown, the seal 22 includes a seal seat 221 and a sealing ring 222. The seal seat 221 has a gas passage 223 that communicates the outside with the gas storage cavity 11. The sealing ring 222 is disposed between the seal seat 221 and the moving part 212. The sealing ring 222 is fixed on the seal seat 211, cooperates with the moving part 212, allows and blocks the passage of gas, and its material can be fluororubber to improve the sealing performance between the moving part 212 and the seal seat 211. While fixing the sealing ring 222, the seal seat 211 provides the gas passage 223. The entire seal 222 can be made of aluminum and is connected and fixed to the gas storage main body 10 by laser welding. It should be understood that Figure 3 and Figure 4 the structure shown in Figure 3 is only a schematic structure of the seal 22, and other structures that can cooperate with the moving part 212 to provide a gas passage 233 and sealing performance should be within the protection scope of this application.

[0047] In a possible implementation, as Figure 4 shown, a clamping groove 2211 is provided on the seal seat 221, and the sealing ring 222 is installed on the seal seat 221 through the clamping groove 2211. By installing the sealing ring 222 in cooperation with the clamping groove 2211, the fastening degree of the sealing ring 222 is ensured, thereby ensuring its sealing performance.

[0048] In a possible implementation, as Figure 3 and 4 shown, one end of the gas passage 223 opposite to the moving part 212 is funnel-shaped. The funnel-shaped gas passage 223 is more conducive to fitting with the moving part 212 and improves the sealing performance. Further, the clamping groove 2211 can be provided with a groove on the funnel slope to cut into the sealing ring 222, and the slope and the sealing ring 222 double-guarantee the fitting degree of the moving part 212 and improve the sealing performance.

[0049] In one implementation, as Figures 2 - 4 shown, a cell gas collection device is composed of a gas storage main body 10 with a gas storage cavity 11, a spring 211, a ball, a sealing ring 222 and a seal seat 211. For the specific cooperation structure, refer to the above implementation. When the internal air pressure of the cell is greater than y, the external atmospheric pressure acting on the ball is greater than the elastic force F of the spring 211 弹 , the ball is pushed downward and opened, and gas enters the gas storage cavity 11. When the internal pressure of the gas storage cavity 11 is balanced with the external pressure, the ball returns to its initial position and plays a sealing role. To improve the sealing performance of the structure and meet the requirement of unidirectional conductive air intake, for the selection and installation of the spring 211, the sealing ring 222, and the ball, the following expressions need to be satisfied:

[0050]

[0051] Where: k is the spring stiffness coefficient, k' is the sealing ring stiffness coefficient, x is the spring compression amount, x' is the sealing ring compression amount, θ is the contact angle between the ball and the sealing ring, m is the mass of the ball, R is the diameter of the ball, P 内 、P 外 are the internal and external air pressures in the gas storage cavity 11 respectively;

[0052] And in order to ensure that the gas collection device of the battery cell can collect gas, F 弹 should not be too large or too small, and F 弹 needs to satisfy the following expression:

[0053]

[0054] In addition, considering that during the operation of the vehicle, due to the vertical acceleration generated by bumps, at this time the ball is subjected to F 加 = ma. When the battery cell is in the static experiment, a = 0. Considering that the ball is not subjected to F 加 the spring compression amount can be adjusted, a spring with a smaller stiffness coefficient can be selected, etc., to appropriately reduce F 弹 ; when it needs to be installed in the vehicle or conduct an experiment that will cause vertical acceleration, a > g, it is necessary to appropriately increase F 弹 to ensure that after the device collects the gas, the valve will not open again to cause gas leakage.

[0055] In one embodiment, as Figure 5 shown, the gas storage main body 10 also has an installation cavity 12 communicating with the gas storage cavity 11. The one-way gas guiding device 20 is installed in the installation cavity 12. Specifically, the sealing member 22 can be fixedly installed at the air inlet end of the installation cavity 12, the spring 211 is installed at the bottom of the installation cavity 12 and connected to support the movable member 212. The sealing member 22, the spring 211 and the movable member 212 together form the one-way gas guiding device 20 in the installation cavity 12. The setting of the installation cavity 12 facilitates the installation and use of the one-way gas guiding device 20. Further, the installation cavity 12 is a cylindrical installation cavity, which is convenient for the movable member 212 to move in the cavity and is also beneficial to the sealing between the sealing member 22 and the movable member 212.

[0056] In a possible embodiment, as Figure 5 shown, there is a support edge 13 between the installation cavity 12 and the gas storage cavity 11. The movable mechanism 21 is arranged on the support edge 13. The function of the support edge 13 is to provide bottom support for the spring 211. The diameter of the gas passage formed by the support edge 13 is slightly smaller than that of the installation cavity 12, and thus the support edge 13 can be formed.

[0057] In a possible implementation, the space of the gas storage cavity 11 is maximized as much as possible. All the space except the installation cavity 12 is used for gas storage to increase the gas storage capacity. To ensure mechanical strength, the wall thickness of the gas storage cavity 11 on the gas storage main body 10 needs to be greater than or equal to 1 mm. The bottom of the gas storage cavity 11 also has a sealing bottom cover 14, whose function is to seal the bottom of the gas storage cavity 11. It should be understood that the sealing bottom cover 14 can be an integral structure with the gas storage main body 10. However, for more convenient forming of the gas storage cavity 11, usually, the gas storage cavity 11 is formed by drilling in the gas storage main body 10. After drilling, the sealing bottom cover 14 seals to form a sealed gas storage cavity 11. The sealing bottom cover 14 can be connected to the gas storage main body 10 by laser welding, and the material can be aluminum. Further, the installation cavity 12, the support edge 13, and the gas storage cavity 11 inside the gas storage main body 10 can all be formed by drilling to form cavity structures with different diameters. The gas storage main body 10 can be a rod-shaped metal object, usually aluminum metal.

[0058] Further, as Figure 6 shown, the present application also provides a battery, including a housing 30, an electric core 40 installed in the housing 30, and the electric core gas collection device as described above; the electric core gas collection device is arranged in the space between the electric core 40 and the housing 30. Specifically, one or more electric core gas collection devices can be arranged inside the housing 30. The gas storage main body 10 is located at the extra space between the electric core 40 and the housing 30 inside the battery, without occupying extra space.

[0059] In one implementation, the height of the gas storage main body 10 is less than or equal to that of the electric core 40. The cross-sectional dimensions and shape of the gas storage main body 10 fit the space between the electric core 40 and the housing 30, that is, the length dimension of the gas storage main body 10 is basically the same as the height of the electric core 40 inside the battery, and the cross-sectional dimensions and shape fit the gap between the electric core 40 and the housing 30 inside the battery, so as to utilize the existing space and increase the gas storage function of, for example, a square aluminum shell electric core without reducing the volume energy density of the electric core.

[0060] In a possible implementation, as Figure 7 shown, a slot 31 is provided on the inner wall of the housing 30. The gas storage main body 10 can be inserted and fixed in the slot 31 to play a fixing role and prevent the gas storage main body 10 from shaking inside the battery and affecting the normal use of the battery. Further, after the gas storage main body 10 is inserted into the slot 31 for preliminary fixing, the gas storage main body 10 can be welded to the inner wall of the housing 30 by welding to play a final fixing role.

[0061] Based on the above implementation, in a specific embodiment, for a certain square shell double-wound core battery, with a thickness of 72 mm, a shoulder height of 204 mm, and an internal wound core height of 188 mm, the two wound cores and the aluminum shell inside the electric core can accommodate a gas storage main body 10 with an equilateral right triangle cross-section and a short side length of 13 mm on the side. When not storing gas, the ball is subjected to an upward force F from the spring 211弹 = 3N. The overall length of the gas storage main body 10 of this type of battery cell is the same as the height of the wound core, which is 188 mm. The diameter of the internal gas storage cavity 11 is 5.4 mm and the height is 150 mm. The volume of high-pressure gas that can be accommodated is 3.4 cm 3 , and the volume will further increase after decompression to standard atmospheric pressure, which is sufficient for multiple gas analyses. By adding a battery cell gas collection device to the existing space of the square battery cell, high-pressure gas sufficient for multiple gas analyses can be stored, providing gas composition data for the open valve failure analysis, and thus helping to infer the cause of the gas open valve.

[0062] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0063] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A cell gas collection device, characterized in that, Comprising: A gas storage main body (10) having a gas storage cavity (11); A one-way gas guiding device (20) disposed within the gas storage main body (10), the one-way gas guiding device (20) including a moving mechanism (21) and a seal (22), the moving mechanism (21) moving relative to the seal (22) to allow or block gas from entering the gas storage cavity (11).

2. The cell gas collection device according to claim 1, wherein The moving mechanism includes a moving member (212) and a spring (211), the spring (211) supporting the moving member (212) such that it abuts the seal (22) at an initial position to block gas from entering the gas storage cavity (11); When the external air pressure is greater than the air pressure within the gas storage cavity (11), the moving member (212) compresses the spring (211) to create a gap with the seal (22) to allow gas to enter the gas storage cavity (11).

3. The cell gas collection device according to claim 2, wherein, The surface of the moving member (212) in contact with the seal (22) is an arc surface or a conical surface.

4. The cell gas collection device according to claim 2 or 3, characterized in that, The seal (22) includes a seal seat (221) and a sealing ring (222), the seal seat (221) having a gas passage (223) communicating the outside with the gas storage cavity (11), the sealing ring (222) being disposed between the seal seat (221) and the moving member (212).

5. The cell gas collection device according to claim 4, characterized in that, A card slot (2211) is provided on the seal seat (221), and the sealing ring (222) is installed on the seal seat (221) through the card slot (2211).

6. The cell gas collection device according to claim 4, characterized in that, One end of the gas passage (223) relative to the moving member (212) is funnel-shaped.

7. The cell gas collection device according to claim 1, wherein The gas storage main body (10) further has an installation cavity (12) communicating with the gas storage cavity (11), and the one-way gas guiding device (20) is installed within the installation cavity (12).

8. The cell gas collection device according to claim 7, wherein, A support edge (13) is provided between the installation cavity (12) and the gas storage cavity (11), and the moving mechanism (21) is disposed on the support edge (13).

9. A battery, characterized in that, Including a housing (30), an electric core (40) installed within the housing (30), and an electric core gas collection device as described in any one of claims 1 - 8; the electric core gas collection device is disposed in the space between the electric core (40) and the housing (30).

10. The battery according to claim 9, characterized in that, The height of the gas storage main body (10) is less than or equal to the electric core (40), and the cross-sectional dimensions and shape of the gas storage main body (10) fit the space between the electric core (40) and the housing (30).

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