Cover plate structure and battery

Abstract

The utility model belongs to the technical field of batteries, and discloses a cover plate structure and a battery, the cover plate structure comprises a top cover plate and at least two supporting plates, the top cover plate is provided with an anti-explosion valve and a protruding part, and the protruding part and the anti-explosion valve are arranged at intervals; the supporting plates are fixedly connected with the protruding parts, first exhaust channels are formed between the adjacent supporting plates, second exhaust channels are formed between the supporting plates and the top cover plate, and the first exhaust channels communicate with the second exhaust channels. The projection of the first exhaust channel in the first direction at least partially coincides with the projection of the anti-explosion valve in the first direction. Therefore, when thermal runaway occurs in the battery and a plastic part is fused and fails, the supporting plate can limit the end part of the pole group, so that the pole group is not easy to move in the shell due to the influence of airflow; and the first exhaust channel and the second exhaust channel can be convenient for gas to quickly reach the explosion-proof valve, so that the exhaust effect of the explosion-proof valve and the safety of the battery are improved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a cover plate structure and a battery. Background Technology

[0002] A battery is a device that converts chemical energy into electrical energy. Lithium-ion batteries have become the representative of modern high-performance batteries due to their advantages such as high operating voltage, high specific energy, large capacity, low self-discharge, good cycle performance, long service life, light weight, and small size.

[0003] Long-cell lithium-ion batteries are typically designed with tabs on both sides, meaning that tabs of opposite polarity are located at both ends of the cell. A long-cell lithium-ion battery includes a cover plate, casing, electrode assembly, electrolyte, etc. The casing and cover plate are welded together to form a sealed space with a certain mechanical strength. The electrode assembly is placed within this sealed space and protected by the casing and cover plate. The cover plate is located at both ends of the casing. The tabs connected to both ends of the electrode assembly are fixed to the corresponding electrode post bases on the cover plate via laser welding to achieve electrical connection with external circuitry. Plastic parts are provided on the sidewalls of the cover plate facing the electrode assembly; these parts are used to fix and insulate the electrode assembly. An explosion-proof valve is also installed on the cover plate; when a short circuit occurs inside the battery and thermal runaway occurs, gas can be released to the outside through the explosion-proof valve.

[0004] However, since plastic parts are usually made of PP (polypropylene) material, they have low strength and poor heat resistance. When thermal runaway occurs inside the battery, the plastic parts may melt and fail due to excessive temperature, and lose their fixation to the electrode assembly. This increases the gap between the electrode assembly and the cover plate and the shell. The electrode assembly has a high degree of freedom inside the shell. As high-temperature and high-pressure gas is vented in a directional manner towards the explosion-proof valve, the electrode assembly will move around under the action of the high-temperature and high-pressure gas flow and block the explosion-proof valve, thus blocking the airflow channel, reducing the venting effect of the explosion-proof valve and the safety performance of the battery cell. Utility Model Content

[0005] The purpose of this utility model is to provide a cover plate structure and a battery to solve the problem of poor exhaust effect caused by the blockage of the explosion-proof valve and airflow channel when thermal runaway occurs inside the battery.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, a cover plate structure includes: a top cover plate, on which an explosion-proof valve and a protrusion are disposed, the protrusion being spaced apart from the explosion-proof valve; at least two support plates, the support plates being fixedly connected to the protrusion, a first exhaust channel being formed between adjacent support plates, and a second exhaust channel being formed between the support plates and the top cover plate, the first exhaust channel being connected to the second exhaust channel; the projection of the first exhaust channel in a first direction at least partially coincides with the projection of the explosion-proof valve in the first direction.

[0008] Preferably, the support plate has a first exhaust hole, which is connected to the second exhaust channel.

[0009] Preferably, the length direction of the protrusion is parallel to the length direction of the explosion-proof valve; and / or, the length direction of the support plate is perpendicular to the length direction of the explosion-proof valve.

[0010] Preferably, the cross-sectional area of ​​the protrusion gradually decreases from the end facing the top cover plate to the end facing away from the top cover plate.

[0011] Preferably, a plurality of protrusions are provided, and the plurality of protrusions are arranged at intervals along the length direction of the top cover plate, and the two ends of the support plate are respectively fixedly connected to the protrusions located at both ends of the top cover plate.

[0012] Preferably, the length of the protrusions on both sides of the explosion-proof valve is less than the length of the protrusions at both ends of the top cover plate.

[0013] Preferably, the height of the protrusion is in the range of 1.5mm-3mm.

[0014] Preferably, the cover plate structure further includes a plastic part connected to the support plate, the plastic part being disposed on the side of the support plate opposite to the top cover plate.

[0015] Preferably, the plastic part has a second vent hole, which is connected to the second vent channel.

[0016] In a second aspect, a battery includes a cell, a casing, and a cover plate structure as described above, wherein the casing is fixedly connected to the top cover plate, and the cell is disposed within the space enclosed by the top cover plate and the casing.

[0017] The beneficial effects of this utility model are:

[0018] A cover plate structure includes a top cover plate and at least two support plates. The top cover plate is provided with an explosion-proof valve and a protrusion, with the protrusion and the explosion-proof valve spaced apart. The support plates are fixedly connected to the protrusions, and a first exhaust channel is formed between adjacent support plates. A second exhaust channel is formed between the support plates and the top cover plate. The first exhaust channel and the second exhaust channel are connected. The projection of the first exhaust channel in a first direction at least partially coincides with the projection of the explosion-proof valve in the first direction.

[0019] Thus, when thermal runaway occurs inside the battery, the support plates, with their high strength and good heat resistance, can maintain support for the electrode assembly after the plastic parts melt and fail, preventing the electrode assembly from being affected by high-temperature and high-pressure gases and moving within the casing. The spaced support plates form a first exhaust channel, and the protrusions allow a second exhaust channel to be formed between the support plates and the top cover plate. This facilitates the rapid discharge of high-temperature and high-pressure gases to the explosion-proof valve through the first and second exhaust channels. The projection of the first exhaust channel in the first direction coincides with the projection of the explosion-proof valve in the first direction, allowing the high-temperature and high-pressure gases to directly contact the explosion-proof valve, reducing obstruction to the valve, improving the exhaust effect of the explosion-proof valve, and enhancing the safety of the battery. Attached Figure Description

[0020] Figure 1 This is a partial structural schematic diagram of the cover plate structure in one embodiment of the present invention;

[0021] Figure 2 This is a partial structural schematic diagram of the cover plate structure in one embodiment of the present invention;

[0022] Figure 3 This is an exploded view of the cover plate structure in one embodiment of the present invention. Figure 1 ;

[0023] Figure 4 This is an exploded view of the cover plate structure in one embodiment of the present invention. Figure 2 ;

[0024] Figure 5 This is a schematic diagram of the cover plate structure in one embodiment of the present invention.

[0025] In the picture:

[0026] 1. Top cover plate; 11. Explosion-proof valve; 12. Protrusion; 2. Support plate; 21. First exhaust port; 3. First exhaust channel; 4. Second exhaust channel; 5. Plastic part; 51. Second exhaust port; X, First direction. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0028] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0029] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0030] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element 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" and "second" are only used for distinction in description and have no special meaning.

[0031] See Figure 1 This utility model provides a cover plate structure, including a top cover plate 1 and at least two support plates 2. The top cover plate 1 is provided with an explosion-proof valve 11 and a protrusion 12, with the protrusion 12 and the explosion-proof valve 11 spaced apart. The support plates 2 are fixedly connected to the protrusions 12, and a first exhaust channel 3 is formed between adjacent support plates 2, that is, adjacent support plates 2 are arranged at intervals. A second exhaust channel 4 is formed between the support plates 2 and the top cover plate 1, and the first exhaust channel 3 and the second exhaust channel 4 are connected. The projection of the first exhaust channel 3 in the first direction X at least partially overlaps with the projection of the explosion-proof valve 11 in the first direction X.

[0032] In this embodiment, the top cover plate 1 is a smooth aluminum sheet. The length direction of the top cover plate 1 is parallel to the height direction of the battery. The height direction of the protrusion 12 is parallel to the first direction X. The protrusion 12 is formed on the top cover plate 1 by stamping and is set towards the inside of the battery. The explosion-proof valve 11 is welded on the top cover plate 1. The length direction of the support plate 2 is parallel to the length direction of the top cover plate 1. The length direction of the first exhaust channel 3 is parallel to the length direction of the top cover plate 1. There are two support plates 2. The support plates 2 are made of aluminum material. The support plates 2 and the protrusion 12 are fixedly connected by welding.

[0033] Thus, when thermal runaway occurs inside the battery, the aluminum support plate 2, with its high strength and good heat resistance, is less likely to melt and block the explosion-proof valve 11 under the action of high-temperature and high-pressure gas. If the plastic part 5 melts, it is less likely to come into contact with the explosion-proof valve 11 due to the blocking effect of the support plate 2. The support plate 2 can maintain support for the end of the electrode assembly, making it less likely to move within the casing. Furthermore, since the first exhaust channel 3 is formed between the spaced support plates 2, and the protrusion 12 can support the support plate 2, a second exhaust channel 4 is formed between the support plate 2 and the top cover plate 1. This allows high-temperature and high-pressure gas to be quickly discharged to the explosion-proof valve 11 through the first exhaust channel 3 and the second exhaust channel 4. The projection of the first exhaust channel 3 in the first direction X coincides with the projection of the explosion-proof valve 11 in the first direction X, allowing the high-temperature and high-pressure gas to directly contact the explosion-proof valve 11, improving the exhaust efficiency of the explosion-proof valve 11, reducing the risk of the exhaust channel being blocked, and improving the safety of the battery.

[0034] It is understandable that the number of support plates 2 is not limited to two. The number of protrusions and support plates 2 can be flexibly adjusted according to the size and specifications of the top cover plate 1, so that the protrusions can stably support the support plates 2, so that high-temperature and high-pressure gas can be discharged to the explosion-proof valve 11 through the first exhaust channel 3 and the second exhaust channel 4.

[0035] See Figure 1 In some embodiments, the support plate 2 has a first exhaust hole 21, which communicates with the second exhaust channel 4. In this embodiment, multiple first exhaust holes 21 are provided, and the multiple first exhaust holes 21 are arranged at intervals along the length direction of the support plate 2.

[0036] Thus, by opening the first vent hole 21 on the support plate 2, not only can the support plate 2 maintain a certain structural strength, but also the high temperature and high pressure gas generated by thermal runaway inside the battery can flow rapidly into the second vent channel 4 through the first vent hole 21, further improving the venting efficiency of the explosion-proof valve 11.

[0037] It is understood that the shape and position of the first vent 21 can be flexibly adjusted so that the high temperature and high pressure gas generated inside the battery can quickly reach the explosion-proof valve 11 and be discharged to the outside. This embodiment does not limit this.

[0038] See Figure 2 and Figure 3 In some embodiments, the length direction of the protrusion 12 is parallel to the length direction of the explosion-proof valve 11; the length direction of the support plate 2 is perpendicular to the length direction of the explosion-proof valve 11. That is, the length direction of the protrusion 12 is perpendicular to the length direction of the support plate 2.

[0039] Thus, the length direction of the protrusion 12 is parallel to the length direction of the explosion-proof valve 11, which can save the area occupied by the top cover plate 1 in the length direction and enable the protrusion 12 to provide stable support for the support plate 2. The length direction of the support is perpendicular to the length direction of the explosion-proof valve 11, which can improve the structural strength of the top cover plate 1 in the length direction, prevent the top cover plate 1 from deforming under the action of high temperature and high pressure gas when the battery thermal runaway, facilitate the gas to be discharged to the outside through the explosion-proof valve 11, improve the exhaust effect of the explosion-proof valve 11 and the safety of the battery.

[0040] It is understandable that the protrusion 12 and the support can also be set at an angle, and the connection position of the protrusion 12 and the support can be flexibly adjusted. In this embodiment, the protrusion 12 and the support are set vertically in order to save the space occupied by the protrusion 12 and the support on the top cover plate 1.

[0041] See Figure 2 In some embodiments, the cross-sectional area of ​​the protrusion 12 gradually decreases from the end facing the top cover plate 1 to the end facing away from the top cover plate 1. In this embodiment, the protrusion 12 is a conical boss structure.

[0042] Thus, as the cross-sectional area of ​​the protrusion 12 gradually decreases, the gap between the top cover plate 1 and the support plate 2 will gradually increase, allowing the gas to flow more smoothly to the explosion-proof valve 11, thereby improving the exhaust effect of the explosion-proof valve 11 and the safety performance of the battery cell.

[0043] It is understandable that the protrusion 12 can also be a cuboid structure with a constant cross-sectional area. The orientation of the protrusion 12 can be flexibly adjusted according to actual needs and is not limited to a conical protrusion structure.

[0044] See Figure 3 In some embodiments, multiple protrusions 12 are provided, and the multiple protrusions 12 are arranged at intervals along the length direction of the top cover plate 1. The two ends of the support plate 2 are respectively fixedly connected to the protrusions 12 located at both ends of the top cover plate 1. In this embodiment, two protrusions 12 are symmetrically arranged on both sides of the explosion-proof valve 11.

[0045] Thus, the support plate 2 is fixedly connected to the protrusions 12 located at both ends of the top cover plate 1, which can limit the relative position of the support plate 2 on the top cover plate 1, so that the support plate 2 can provide stable support for the plastic part 5; when thermal runaway occurs inside the battery, even if the plastic part 5 melts and deforms at high temperature, the high temperature and high pressure gas can be discharged to the vicinity of the explosion-proof valve 11 through the first exhaust channel 3 and the second exhaust channel 4, so as to prevent the plastic part 5 from blocking the explosion-proof valve 11 and the exhaust channel after melting, so that the high temperature and high pressure gas can be discharged to the outside in time, improving the exhaust effect of the explosion-proof valve 11 and the safety performance of the battery cell.

[0046] It is understandable that the number of protrusions 12 can be flexibly adjusted according to actual needs. The protrusions 12 can also be asymmetrically arranged on both sides of the explosion-proof valve 11. In this embodiment, the protrusions 12 are symmetrically arranged on both sides of the explosion-proof valve 11 in order to improve the structural strength of each part of the support plate 2 and avoid blocking the first exhaust channel 3 or the second exhaust channel 4 due to the deformation of the support plate 2.

[0047] See Figure 3 In some embodiments, the length of the protrusions 12 on both sides of the explosion-proof valve 11 is less than the length of the protrusions 12 on both ends of the top cover plate 1.

[0048] Thus, the protrusions 12 at both ends of the top cover plate 1 are longer, which increases the contact area between the support plate 2 and the protrusions 12, allowing the support plate 2 to be stably welded to the protrusions 12. The protrusions 12 on both sides of the explosion-proof valve 11 are shorter, which increases the area of ​​the second exhaust channel 4, so that when thermal runaway occurs inside the battery, high-temperature and high-pressure gas can be quickly discharged to the outside through the explosion-proof valve 11, improving the exhaust effect of the explosion-proof valve 11 and the safety performance of the battery cell.

[0049] It is understandable that the length of the protrusions 12 on both sides of the explosion-proof valve 11 can be equal to or greater than the length of the protrusions 12 on both ends of the top cover plate 1, which will not be elaborated here.

[0050] See Figure 3 In some embodiments, the height of the protrusion 12 ranges from 1.5mm to 3mm. For example, the height of the protrusion 12 may be 1.5mm, 2mm, 2.5mm, or 3mm.

[0051] See Figure 4 and Figure 5 In some embodiments, the cover plate structure further includes a plastic part 5 connected to the support plate 2, the plastic part 5 being disposed on the side of the support plate 2 opposite to the top cover plate 1. In this embodiment, the plastic part 5 is fixedly connected to the top cover plate 1, and the length direction of the plastic part 5 is parallel to the length direction of the top cover plate 1. Further, the plastic part 5 has a second vent hole 51, which communicates with the second vent channel 4.

[0052] Multiple second vent holes 51 are provided, and the multiple second vent holes 51 are distributed at intervals along the length direction of the plastic part 5.

[0053] Thus, when the battery experiences thermal runaway, the high-temperature and high-pressure gas can be discharged through the second vent 51 into the first vent channel 3 and the second vent channel 4, improving the venting efficiency. After the plastic part 5 melts and fails, the support plate 2 can limit and support the end of the electrode group, preventing the electrode group from moving and blocking the explosion-proof valve 11, thereby improving the venting effect of the explosion-proof valve 11 and the safety performance of the battery cell.

[0054] It is understood that the number and distribution of the second exhaust holes 51 can be flexibly adjusted, and this embodiment does not limit this.

[0055] See Figure 5 This utility model provides a battery, including a battery cell (not shown in the figure), a casing (not shown in the figure), and a cover plate structure. The casing is fixedly connected to a top cover plate 1, and the battery cell is disposed within the space formed by the top cover plate 1 and the casing. In this embodiment, the plastic part 5 is disposed on the side of the support plate 2 facing the battery cell.

[0056] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A cover plate structure, characterized in that, include: Top cover plate (1), on which an explosion-proof valve (11) and a protrusion (12) are provided, the protrusion (12) and the explosion-proof valve (11) being spaced apart; At least two support plates (2) are fixedly connected to the protrusion (12), a first exhaust channel (3) is formed between adjacent support plates (2), and a second exhaust channel (4) is formed between the support plate (2) and the top cover plate (1). The first exhaust channel (3) and the second exhaust channel (4) are connected. The projection of the first exhaust passage (3) in the first direction (X) at least partially coincides with the projection of the explosion-proof valve (11) in the first direction (X).

2. The cover plate structure according to claim 1, characterized in that, The support plate (2) is provided with a first exhaust hole (21), which is connected to the second exhaust channel (4).

3. The cover plate structure according to claim 1, characterized in that, The length direction of the protrusion (12) is parallel to the length direction of the explosion-proof valve (11); and / or, the length direction of the support plate (2) is perpendicular to the length direction of the explosion-proof valve (11).

4. The cover plate structure according to claim 1, characterized in that, The cross-sectional area of ​​the protrusion (12) gradually decreases from the end facing the top cover plate (1) to the end away from the top cover plate (1).

5. The cover plate structure according to any one of claims 1-4, characterized in that, The protrusions (12) are provided in multiple ways, and the multiple protrusions (12) are arranged at intervals along the length direction of the top cover plate (1). The two ends of the support plate (2) are respectively fixedly connected to the protrusions (12) located at both ends of the top cover plate (1).

6. The cover plate structure according to claim 5, characterized in that, The length of the protrusions (12) located on both sides of the explosion-proof valve (11) is less than the length of the protrusions (12) located at both ends of the top cover plate (1).

7. The cover plate structure according to any one of claims 1-4, characterized in that, The height of the protrusion (12) ranges from 1.5mm to 3mm.

8. The cover plate structure according to any one of claims 1-4, characterized in that, The cover plate structure also includes a plastic part (5) connected to the support plate (2), the plastic part (5) being disposed on the side of the support plate (2) away from the top cover plate (1).

9. The cover plate structure according to claim 8, characterized in that, The plastic part (5) has a second vent (51), which is connected to the second vent channel (4).

10. A battery, characterized in that, It includes a battery cell, a housing, and a cover plate structure as described in any one of claims 1-9, wherein the housing is fixedly connected to the top cover plate (1), and the battery cell is disposed within the space enclosed by the top cover plate (1) and the housing.

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