Lithium battery structure

Abstract

The utility model discloses a lithium battery structure. The lithium battery structure comprises a battery cell and a shell, the interior of the shell is hollow and is used for accommodating the battery cell; an anti-explosion valve hole is formed in the bottom of the shell; an exhaust channel is integrally formed on the side surface, provided with the anti-explosion valve hole, of the shell; the exhaust channel is positioned on one side, close to the battery cell, of the side surface of the shell; the exhaust channel passes through the anti-explosion valve hole, and the two ends of the exhaust channel in the length direction extend to the side edge of the shell. According to the scheme, the exhaust channel is arranged on the side face, where the anti-explosion valve hole is located, of the shell, the exhaust channel passes through the anti-explosion valve hole, and gas in the battery cell can flow to the anti-explosion valve through the exhaust channel and is finally exhausted through the anti-explosion valve. In addition, the exhaust channel in the scheme is arranged on the shell in an integrated molding manner, so that the battery structure is more compact, and the exhaust channel is formed on the shell in the integrated molding manner, so that the connection of parts in other manners with the shell is avoided, and the risk of shell breakage caused by stress concentration of connecting points is eliminated.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, and more specifically, to a lithium battery structure. Background Technology

[0002] Lithium-ion batteries are widely used due to their high energy density, lack of memory effect, long cycle life per cell, high efficiency, cleanliness, and pollution-free operation. Battery safety has always been a top priority for the industry. Batteries with better safety are more favored by the market, and major battery manufacturers and OEMs are racing to design highly safe battery products, conducting rigorous thermal runaway tests to verify battery safety.

[0003] As the energy storage component of a battery, the battery cell can generate abnormal gases inside the casing during use due to factors such as the charger and internal chemical reactions. This can lead to excessive internal pressure, potentially causing a battery explosion. A battery explosion can damage electronic products or even injure the user. Furthermore, for large batteries used in new energy vehicles, buses, and energy storage power stations, battery explosions directly threaten human life and property.

[0004] Therefore, when the internal pressure of the battery is too high, in order to prevent the battery from exploding, the pressure inside the battery casing needs to be released. The traditional explosion-proof method is to install a rupture disc on the battery cover. When the internal pressure of the battery is too high, the pressure is released by bursting through the rupture disc. Later, in order to ensure that the heat emitted after the explosion-proof valve opens after the thermal runaway of the vehicle battery system will not be immediately transferred to the passenger compartment, the position of the explosion-proof valve was moved from the cover to the side of the casing in this scenario. However, this also brought new problems. After the stacked cells thermal runaway, they will expand due to heat and press against the explosion-proof valve and the casing, which will prevent the gas inside the cell from being discharged in time and increase the risk of cell structural failure. Utility Model Content

[0005] This invention provides a lithium battery structure that increases the heat dissipation area between the cell and the bottom of the casing, thereby reducing the risk of battery thermal runaway.

[0006] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0007] A lithium battery structure includes a battery cell and a housing; the housing is hollow inside to accommodate the battery cell; the bottom of the housing has an explosion-proof valve hole; an exhaust channel is integrally formed on the side of the housing where the explosion-proof valve hole is located, the exhaust channel being located on the side of the housing near the battery cell; the exhaust channel passes through the explosion-proof valve hole, and both ends of the exhaust channel extend to the side of the housing in the length direction.

[0008] In this design, an exhaust channel is provided on the side of the casing where the explosion-proof valve hole is located. The exhaust channel passes through the explosion-proof valve hole, allowing gas inside the battery cell to flow through the exhaust channel to the explosion-proof valve and ultimately be discharged. Furthermore, the exhaust channel in this design is integrally molded into the casing, making the battery structure more compact. This integral molding method also avoids connecting the exhaust channel to the casing via other components, eliminating the risk of casing breakage due to stress concentration at connection points.

[0009] As a further improvement, the maximum depth of the exhaust channel is 20%-100% of the wall thickness of the housing it is located in, so as to avoid the exhaust channel being too small due to the exhaust area being too small, which would affect the airflow.

[0010] As a further improvement, the maximum depth of the exhaust channel is less than 50% of the wall thickness of the housing in which it is located. This satisfies both gas flow requirements and housing strength requirements.

[0011] As a further improvement, the depth of the exhaust channel gradually increases from the side of the housing to the explosion-proof valve port. This guides the gas within the exhaust channel, allowing it to flow rapidly to the explosion-proof valve port.

[0012] As a further improvement, the two ends of the exhaust channel extend beyond the sides of the explosion-proof valve orifice in the width direction. This positions the explosion-proof valve orifice within the exhaust channel, allowing airflow to reach it.

[0013] As a further improvement, the width of the exhaust channel is smaller than the width of the bottom surface of the housing, enabling the housing structure to support the battery cell.

[0014] As a further improvement, the exhaust passage has a trapezoidal cross-section along its width, which increases the flow area of ​​the exhaust passage.

[0015] As a further improvement, the bottom surface of the exhaust channel is arc-shaped, and the center of the exhaust channel coincides with the center of the explosion-proof valve orifice. This allows the airflow to be maximized and located close to the center of the exhaust channel, flowing towards the explosion-proof valve and being discharged.

[0016] As a further improvement, the centerline of the exhaust channel may or may not coincide with the centerline of the bottom surface of the housing.

[0017] As a further improvement, the exhaust channel has at least one. The structure between adjacent exhaust channels can support the battery cell, thereby further preventing the exhaust channel from being blocked when the battery cell expands.

[0018] Other technical problems that the lithium battery structure of this utility model can solve, other technical features contained in the technical solution, and the advantages brought by these technical features will be further explained in detail with reference to the accompanying drawings. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the battery casing structure;

[0020] Figure 2 This is a front view of the battery casing structure;

[0021] Figure 3 This is an enlarged schematic diagram of the exhaust channel at point A in Example 1;

[0022] Figure 4 This is an enlarged schematic diagram of the exhaust channel at point A in Example 2;

[0023] Figure 5 This is an enlarged schematic diagram of the exhaust channel at point A in Example 3;

[0024] Figure 6 This is an enlarged schematic diagram of the exhaust channel at point A in Example 4;

[0025] Figure 7 This is a schematic diagram of the cross-section of the exhaust passage BB at point A under one condition.

[0026] Label Explanation:

[0027] 1. Housing; 2. Explosion-proof valve; 3. Exhaust channel; 31. Opening on the channel; 32. Bottom surface of the channel. Detailed Implementation

[0028] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings and embodiments.

[0029] The structures, proportions, and sizes illustrated in the accompanying drawings are solely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0030] Example 1

[0031] This embodiment provides a lithium battery structure, including a cell and a casing 1.

[0032] The housing 1 has openings at both ends and is hollow inside. The bottom of the housing 1 has an explosion-proof valve hole 2, and the battery cell is installed inside the housing 1. In one application, this lithium battery structure is used in a vehicle, where the direction of gravity acting on the lithium battery structure is towards the bottom of the housing 1. In this design, the explosion-proof valve hole 2 is located at the bottom of the housing 1. In the event of thermal runaway, the high-temperature gas inside the battery rushes out through the explosion-proof valve hole 2 in a direction away from passengers, providing them with time to escape and improving safety.

[0033] Specifically, the two ends of the battery cell are connected to terminals, which are located on the open sides of the two ends of the housing 1.

[0034] like Figure 1 and Figure 2 As shown, in this embodiment, an exhaust channel 3 is integrally formed on the side of the housing 1 where the explosion-proof valve hole 2 is provided. The exhaust channel 3 is located on the side of the housing 1 near the battery cell. The exhaust channel 3 passes through the explosion-proof valve hole 2, and both ends of the exhaust channel 3 extend to the side of the housing 1 in the length direction.

[0035] An exhaust channel 3 is provided on the side of the housing 1 where the explosion-proof valve hole 2 is located. The exhaust channel 3 passes through the explosion-proof valve hole 2, and the gas inside the battery cell can flow through the exhaust channel 3 to the explosion-proof valve and finally be discharged through the explosion-proof valve.

[0036] Furthermore, the exhaust channel 3 in this design is integrally molded into the casing 1, making the battery structure more compact and reducing the weight of the battery pack, thus achieving a lightweight design. Since the battery cells repeatedly expand during charging and discharging, the pressure from this expansion repeatedly acts on the casing. The integral molding of the exhaust channel 3 on the casing 1 avoids connecting the battery to the casing 1 via other components, eliminating the risk of casing breakage due to stress concentration at connection points.

[0037] In this design, the housing 1 is made of aluminum. Regarding the integrated molding of the exhaust channel 3 on the housing 1, one method is to use aluminum extrusion and cold drawing, which is a low-cost method.

[0038] Preferably, the maximum depth of the exhaust channel 3 accounts for 20%-100% of the wall thickness of the housing 1 in which it is located. Combined with... Figure 3 As shown, the opening at the upper end of the exhaust channel 3 is the upper opening 31, and the bottom surface at the lower end of the exhaust channel 3 is the lower bottom surface 32. The depth of the exhaust channel 3 is the distance between the upper opening 31 and the lower bottom surface 32. If the maximum depth of the exhaust channel 3 is set too small, the exhaust area of ​​the exhaust channel 3 will be too small, affecting airflow.

[0039] More preferably, the maximum depth of the exhaust channel 3 is less than 50% of the wall thickness of the housing 1 it is located in, that is, the maximum depth of the exhaust channel 3 is 20%-50% of the wall thickness of the housing 1 it is located in, which satisfies both gas flow requirements and housing strength requirements. Setting the maximum depth of the exhaust channel 3 too large would result in the housing 1 wall being too thin, affecting the strength of the housing.

[0040] The direction in which the exhaust channel 3 extends toward the openings at both ends of the housing 1 is its length direction, and the direction perpendicular to its length direction is its width direction. The two ends of the exhaust channel 3 in the width direction extend beyond the two sides of the explosion-proof valve hole 2, so that the explosion-proof valve hole 2 is located in the exhaust channel 3, allowing airflow to flow to the explosion-proof valve hole 2.

[0041] In addition, the width of the exhaust channel 3 is smaller than the width of the bottom surface of the housing 1. This allows the battery cell to be supported on the bottom surface of the housing 1 where the exhaust channel 3 is not located, preventing the battery cell from expanding and blocking the exhaust channel 3.

[0042] In this embodiment, the exhaust channel 3 has a rectangular cross-section along its width direction, which facilitates processing. Preferably, the centerline aa of the exhaust channel 3 coincides with the centerline of the bottom surface of the housing 1, which facilitates the positioning of the exhaust channel 3 during processing.

[0043] In other cases, the center line aa of the exhaust channel 3 may not coincide with the center line of the bottom surface of the casing 1. Normally, when the battery cell expands, the center of the side of the battery cell closest to that side expands the most. Setting the center line aa of the exhaust channel 3 to not coincide with the center line of the bottom surface of the casing 1 avoids blocking the exhaust channel 3 at the point of maximum expansion of the battery cell.

[0044] In a preferred embodiment, the bottom surface of the exhaust channel 3 and the depth of the exhaust channel 3 are the same from the side of the housing 1 to the explosion-proof valve hole 2, that is, the bottom surface 32 of the channel is flush.

[0045] In other cases, such as Figure 7 As shown, the depth of the exhaust channel 3 gradually increases from the side of the housing 1 to the explosion-proof valve hole 2, which guides the gas in the exhaust channel 3 so that the gas flows quickly to the explosion-proof valve hole 2.

[0046] Example 2

[0047] This embodiment provides a lithium battery structure, such as Figure 4 As shown, in this embodiment, the cross-section of the exhaust channel 3 along its width direction is trapezoidal. Other structures and the arrangement of the exhaust channel 3 are the same as in Embodiment 1.

[0048] In this embodiment, the exhaust channel 3 has a trapezoidal cross-section along its width direction, and the size of the exhaust channel 3 gradually decreases from the upper opening 31 to the lower bottom surface 32. This facilitates demolding during the integral molding of the exhaust channel 3 and further increases the exhaust area of ​​the exhaust channel 3.

[0049] Example 3

[0050] This embodiment provides a lithium battery structure, such as Figure 5 As shown, the bottom surface of the exhaust channel 3 is arc-shaped. Other structures and the arrangement of the exhaust channel 3 are the same as in Embodiment 1.

[0051] In this embodiment, the bottom surface of the exhaust channel 3 is arc-shaped, which can guide the airflow and concentrate a large amount of airflow near the center line aa of the exhaust channel 3, thereby causing a large amount of airflow to flow towards the explosion-proof valve hole 2. Especially when the center line aa of the exhaust channel 3 coincides with the center line of the bottom surface of the housing 1, and when the depth of the exhaust channel 3 gradually increases from the side of the housing 1 to the explosion-proof valve hole 2, a large amount of gas flows towards the explosion-proof valve hole 2, improving the gas discharge efficiency.

[0052] Example 4

[0053] This embodiment provides a lithium battery structure, such as Figure 6 As shown, there is at least one exhaust passage 3. Other structures and the arrangement of exhaust passage 3 are the same as in Embodiment 1.

[0054] In this embodiment, especially when multiple exhaust channels 3 are provided, the structure between adjacent exhaust channels 3 can support the battery cell, thereby further preventing the battery cell from blocking the exhaust channel 3 when it expands.

[0055] The terms “installation,” “setup,” “equipped with,” and “connection” used herein should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0056] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A lithium battery structure, characterized in that, include: Battery cell; The housing (1) is hollow inside and is used to accommodate the battery cell; the bottom of the housing (1) has an explosion-proof valve hole (2); an exhaust channel (3) is integrally formed on the side of the housing (1) where the explosion-proof valve hole (2) is located, and the exhaust channel (3) is located on the side of the housing (1) close to the battery cell; the exhaust channel (3) communicates with the explosion-proof valve hole (2) through the explosion-proof valve hole (2), and both ends of the exhaust channel (3) extend to the side of the housing (1) in the length direction.

2. The lithium battery structure according to claim 1, characterized in that: The maximum depth of the exhaust channel (3) is 20%-100% of the wall thickness of the housing (1) in which it is located.

3. The lithium battery structure according to claim 2, characterized in that: The maximum depth of the exhaust channel (3) is less than 50% of the wall thickness of the housing (1) in which it is located.

4. The lithium battery structure according to claim 2, characterized in that: The depth of the exhaust channel (3) gradually increases from the side of the housing (1) to the explosion-proof valve hole (2).

5. The lithium battery structure according to claim 3, characterized in that: The two ends of the exhaust channel (3) extend beyond the two sides of the explosion-proof valve hole (2) in the width direction.

6. The lithium battery structure according to any one of claims 1-5, characterized in that: The width of the exhaust channel (3) is smaller than the width of the bottom surface of the housing (1).

7. The lithium battery structure according to claim 6, characterized in that: The exhaust passage (3) has a trapezoidal cross-section along its width direction.

8. The lithium battery structure according to claim 6, characterized in that: The bottom surface of the exhaust channel (3) is arc-shaped.

9. The lithium battery structure according to claim 6, characterized in that: The centerline of the exhaust channel (3) may or may not coincide with the centerline of the bottom surface of the housing (1).

10. The lithium battery structure according to claim 6, characterized in that: The exhaust passage (3) has at least one.

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