Battery housing and battery

Abstract

The present invention belongs to the technical field of batteries, and discloses a battery case and a battery. The battery case includes a cover body, a case body, and a first insulating structural member. A liquid injection hole is formed in the wall surface of the cover body or the case body opposite to the tab. On one side of the first insulating structural member opposite to the liquid injection hole, a liquid injection structure composed of a flow guide groove and an overflow groove communicating with each other is provided. A flow guide hole is formed in the flow guide groove, and an overflow hole is formed in the overflow groove. The depth dimension of the flow guide groove is H1, and the depth dimension of the overflow groove is H2, and 1≤H1 / H2≤3 is satisfied. When overflow occurs during the liquid injection process, the overflowing electrolyte flows into the overflow groove and flows out from the overflow hole, thereby ensuring the smooth injection of the electrolyte. By limiting the relationship between the depth dimension H1 and the depth dimension H2, a height difference is formed between the overflow groove and the flow guide groove, thereby playing a buffering role and alleviating the impact of the electrolyte on the electrode group.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and particularly to a battery case and a battery. Background Art

[0002] Lithium-ion batteries are currently widely used in various fields such as transportation power sources, power energy storage power sources, new energy storage power sources, aerospace and military industries due to their advantages of large capacity, high working voltage, strong charge retention ability, long cycle life, etc. The structure of a single lithium battery generally includes a pole group, an electrolyte, a cover plate, a case, an internal and external insulation structure, etc. Among them, the cover plate and the case are usually fixed by laser welding to form a sealed space with a certain structural strength to protect the pole group. The cover plate generally integrates functional areas such as pole columns, explosion-proof valves, liquid injection holes, etc. Among them, the liquid injection hole is usually provided on the cover plate, and a through hole communicating with the liquid injection hole is opened on the internal insulation member, so as to facilitate the inflow of the electrolyte to achieve the purpose of wetting the pole group.

[0003] Among them, the tab of the pole group is connected to the pole column inserted on the internal insulation member and is located inside the internal insulation member. During the liquid injection process, it is necessary to evacuate the inside of the battery. Therefore, the tab of the pole group is affected by the negative pressure inside the battery and will tightly adhere to the internal insulation member, resulting in the tab blocking the through hole on the internal insulation member opposite to the liquid injection hole, causing the flow rate of the electrolyte injected through the liquid injection hole to be greater than the flow rate of the electrolyte flowing out through the through hole, so that a part of the electrolyte cannot flow out in time, thereby causing the overflow of the electrolyte, having a high risk of insulation failure and poor safety. Summary of the Invention

[0004] The purpose of the present invention is to provide a battery case and a battery with a low risk of insulation failure and good safety.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] On the one hand, a battery case is provided. The battery case includes a cover plate body, a case body, and a first insulation structure member. The case body is a hollow shell structure with an opening. The cover plate body is arranged at the opening of the case body to form a receiving cavity for receiving the pole group. A liquid injection hole is opened on the wall surface of the cover plate body or the case body opposite to the side where the pole group extends the tab. The first insulation structure member is located in the receiving cavity and is arranged on the side where the pole group extends the tab.

[0007] A liquid injection structure is provided on the side of the first insulation structure member opposite to the liquid injection hole. The liquid injection structure includes a diversion groove and an overflow groove that communicate with each other. The projection of the diversion groove on the wall surface of the cover plate body or the case body along the first direction covers the liquid injection hole, and a diversion hole penetrating through the diversion groove is opened. An overflow hole penetrating through the overflow groove is opened on the overflow groove.

[0008] The depth dimension of the diversion groove along the first direction is H1, the depth dimension of the overflow groove along the first direction is H2, and 1≤H1 / H2≤3 is satisfied.

[0009] Optionally, a buffer inclined plane is provided between the diversion groove and the overflow groove. The length dimension of the buffer inclined plane along the second direction is L1, and 2mm≤L1≤10mm is satisfied.

[0010] Optionally, the included angle between the buffer inclined plane and the extension plane extending from the bottom surface of the diversion groove towards the overflow groove is θ, and 15°≤θ≤70° is satisfied.

[0011] Optionally, a plurality of diversion holes are provided in the diversion groove. The total effective cross-sectional area of the plurality of diversion holes is S1, and the projected area of the diversion groove on the cover body or the wall surface of the housing body along the first direction is S2, and 0.25≤S1 / S2≤0.6 is satisfied.

[0012] Optionally, the total effective cross-sectional area for the electrolyte to flow through the liquid injection hole is S, and 0.8≤S1 / S≤1.2 is satisfied.

[0013] Optionally, a plurality of overflow holes are provided in the overflow groove. The total effective cross-sectional area of the plurality of overflow holes is S3, and the projected area of the overflow groove on the cover body or the wall surface of the housing body along the first direction is S4, and 0.25≤S3 / S4≤0.6 is satisfied.

[0014] Optionally, the total effective cross-sectional area of the liquid injection hole is S, and 0.6≤S3 / S≤1 is satisfied.

[0015] Optionally, the distance dimension along the second direction between the boundary of the overflow hole closest to the tab among the plurality of overflow holes and the tab is L2, and L2≥1mm is satisfied.

[0016] Optionally, the first insulating structural member is a plastic part integrally formed by an injection molding process.

[0017] On the other hand, a battery is provided. The battery includes a battery cell group and the battery housing as described in any one of the above. The battery cell group is accommodated in the battery housing.

[0018] Advantages of the present invention:

[0019] The present invention provides a battery case. By providing a liquid injection structure composed of a diversion groove and an overflow groove that communicate with each other on a first insulating structural member, and providing a diversion hole in the diversion groove and an overflow hole in the overflow groove, when performing the operation of injecting electrolyte, even if the tab of the electrode group blocks the diversion hole in the diversion groove due to the influence of negative pressure and causes overflow, the overflowing electrolyte will flow into the overflow groove communicating with the diversion groove and flow out from the overflow hole, thereby ensuring the smooth injection of the electrolyte. Moreover, the relationship between the depth dimension H1 of the diversion groove in the first direction and the depth dimension H2 of the overflow groove in the first direction is defined to satisfy 1 ≤ H1 / H2 ≤ 3, so that there is a height difference between the overflow groove and the diversion groove. When the overflowing electrolyte enters the overflow groove, it will overcome gravity and thus consume its own energy, making the electrolyte flowing out through the overflow hole have lower energy, effectively alleviating the impact of the electrolyte outflow on the electrode group. This not only reduces the risk of insulation failure caused by electrolyte overflow and has high safety, but also effectively alleviates the impact of the electrolyte outflow on the electrode group, improves the protection of the electrode group, and improves the product quality.

[0020] The present invention also provides a battery. By applying the above battery case, not only does it have a lower risk of insulation failure and improve the use safety, but it also improves the product quality by reducing the damage to the electrode group during the manufacturing process. Description of the Drawings

[0021] Figure 1 is an exploded view of the structure of the cover plate body side of the battery case provided by the present invention;

[0022] Figure 2 is a cross-sectional view of the structure of the cover plate body side of the battery case provided by the present invention;

[0023] Figure 3 is a schematic structural view of the first insulating structural member of the battery case provided by the present invention.

[0024] In the figure:

[0025] 100, tab;

[0026] 1, cover plate body; 11, liquid injection hole;

[0027] 2, first insulating structural member; 21, liquid injection structure; 211, diversion groove; 212, overflow groove; 213, diversion hole; 214, overflow hole; 215, buffer slope; 22, pole column through hole;

[0028] 3, pole column;

[0029] 4, riveting block;

[0030] 5, second insulating structural member;

[0031] 6. Sealing ring. Detailed implementation manner

[0032] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the convenience of description, only the parts related to the present invention are shown in the drawings, rather than all the structures.

[0033] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0034] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact of the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "over", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature has a higher horizontal height than the second feature. The first feature being "below", "under", and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the first feature has a lower horizontal height than the second feature.

[0035] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationships shown in the drawings. It is only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and do not have special meanings.

[0036] Therefore, in order to reduce the risk of insulation failure caused by electrolyte overflow and improve the safety of the structure, this embodiment provides a battery housing. For the convenience of describing the structural orientation, the thickness direction is defined as the first direction, and the length direction is defined as the second direction.

[0037] Such as Figures 1 to 3As shown in the figure, the battery case includes a cover body 1, a case body, and a first insulating structure member 2. The case body is a hollow shell structure with an opening. The cover body 1 is arranged at the opening of the case body to form a receiving cavity for accommodating the electrode group. A liquid injection hole 11 is formed on the wall surface of the cover body 1 or the case body opposite to the side where the electrode tab 100 of the electrode group extends. The first insulating structure member 2 is located in the receiving cavity and is arranged on the side where the electrode tab 100 of the electrode group extends. The liquid injection structure 21 includes a diversion groove 211 and an overflow groove 212 that communicate with each other. The projection of the diversion groove 211 on the wall surface of the cover body 1 or the case body along the first direction covers the liquid injection hole 11, and a diversion hole 213 penetrating the diversion groove 211 is formed. An overflow hole 214 penetrating the overflow groove 212 is formed on the overflow groove 212. The depth dimension of the diversion groove 211 along the first direction is H1, and the depth dimension of the overflow groove 212 along the first direction is H2, and 1 ≤ H1 / H2 ≤ 3 is satisfied.

[0038] By providing a liquid injection structure 21 composed of a diversion groove 211 and an overflow groove 212 that communicate with each other on the first insulating structure member 2, and forming a diversion hole 213 in the diversion groove 211 and an overflow hole 214 in the overflow groove 212, when performing the operation of injecting electrolyte, even if the electrode tab 100 of the electrode group blocks the diversion hole 213 in the diversion groove 211 due to the influence of negative pressure and causes overflow, the overflowing electrolyte will flow into the overflow groove 212 communicated with the diversion groove 211 and flow out from the overflow hole 214, thus ensuring the smooth injection of the electrolyte. Moreover, the relationship between the depth dimension H1 of the diversion groove 211 along the first direction and the depth dimension H2 of the overflow groove 212 along the first direction is limited to satisfy 1 ≤ H1 / H2 ≤ 3, so that there is a height difference between the overflow groove 212 and the diversion groove 211. Therefore, when the overflowing electrolyte enters the overflow groove 212, it will overcome gravity and consume its own energy, making the energy of the electrolyte flowing out through the overflow hole 214 lower. This effectively alleviates the impact of the flowing electrolyte on the electrode group, not only reducing the risk of insulation failure caused by electrolyte overflow and having high safety, but also effectively alleviating the impact of the flowing electrolyte on the electrode group, improving the protection of the electrode group, and improving the product quality.

[0039] The injection hole 11 can be provided at different positions according to the structural design. When the side of the electrode group extending from the electrode tab 100 is opposite to the cover body 1, the injection hole 11 is provided on the cover body 1. When the side of the electrode group extending from the electrode tab 100 is opposite to a wall of the shell body, the injection hole 11 is provided on the wall of the shell body opposite to the electrode tab 100. In this embodiment, the injection hole 11 is provided on the cover body 1. And the battery shell can be applied to different types of batteries, such as blade batteries or square shell batteries or large cylindrical batteries, etc. In the present embodiment, the battery shell is applied to square shell batteries, and in addition to the cover body 1 and the first insulating structure 2, the battery shell is also provided with a pole 3, a rivet block 4, a second insulating structure 5 and a sealing ring 6, wherein the second insulating structure 5 is arranged on the side of the cover body 1 away from the first insulating structure 2, and the rivet block 4 is arranged on the side of the second insulating structure 5 away from the cover body 1. The pole 3 passes through the first insulating structure 2, the cover body 1 and the second insulating structure 5 and is riveted with the rivet block 4 in sequence, and the sealing ring 6 is sleeved on the pole 3 to seal the gap between the pole 3 and the cover body 1 to prevent leakage of the electrolyte. Therefore, in order to facilitate the pole 3 to pass through the first insulating structure 2, a pole through hole 22 is also provided on the first insulating structure 2.

[0040] Alternatively, if Figure 2 As shown, a buffer slope 215 is provided between the guide groove 211 and the overflow groove 212 , and the length dimension of the buffer slope 215 along the second direction is L1 and satisfies 2mm≤L1≤10mm.

[0041] By setting the length dimension of the buffer slope 215 along the second direction to L1, on the basis of the height difference between the guide groove 211 and the overflow groove 212, there is also a certain lateral interval between the guide groove 211 and the overflow groove 212 along the second direction, thereby further improving the ability to consume the energy carried by the electrolyte itself and further enhancing the buffering effect of the electrolyte. In addition, by limiting the length dimension L1 of the buffer slope 215 along the second direction to satisfy 2mm≤L1≤10mm, on the one hand, it is avoided that the length dimension of the buffer slope 215 along the second direction is too small, resulting in the overflow electrolyte flowing from the guide groove 211 to the overflow groove 212. The path along the second direction is too short, thereby reducing the buffering effect of the overflow electrolyte. On the other hand, it is avoided that the length dimension of the buffer slope 215 along the second direction is too large, resulting in the overflow electrolyte flowing from the guide groove 211. The path along the second direction is too long, thereby consuming a long time and reducing efficiency.

[0042] In this embodiment, the length dimension L1 of the buffer inclined surface 215 in the second direction can be any value between 2 mm and 10 mm or the range between any two values, such as 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, etc.

[0043] Among them, in order to verify the ratio between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction, and the effect of the length dimension L1 of the buffer inclined surface 215 in the second direction on the electrolyte buffering during liquid injection, as well as the effect of the overflow groove 212 communicated with the diversion groove 211 on the overflow during liquid injection, as shown in Table 1, eight sets of embodiments and six sets of comparative examples are provided for verification, and it is observed whether liquid leakage occurs during liquid injection. After the liquid injection is completed, X-ray detection is used to determine whether the electrode group is damaged.

[0044] Table 1

[0045]

[0046] In Embodiment 1, the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction is set to 1, and the length dimension L1 of the buffer inclined surface 215 in the second direction is set to 2 mm. After experimental verification, the electrode group is not damaged, no liquid leakage is found, and the time requirement of the liquid injection process is not exceeded.

[0047] In Embodiment 2, the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction is set to 3, and the length dimension L1 of the buffer inclined surface 215 in the second direction is set to 2 mm. After experimental verification, the electrode group is not damaged, no liquid leakage is found, and the time requirement of the liquid injection process is not exceeded.

[0048] In Embodiment 3, the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction is set to 1, and the length dimension L1 of the buffer inclined surface 215 in the second direction is set to 4 mm. After experimental verification, the electrode group is not damaged, no liquid leakage is found, and the time requirement of the liquid injection process is not exceeded.

[0049] In Embodiment 4, the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction is set to 3, and the length dimension L1 of the buffer inclined surface 215 in the second direction is set to 4 mm. After experimental verification, the electrode group is not damaged, no liquid leakage is found, and the time requirement of the liquid injection process is not exceeded.

[0050] In Example 5, the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction is set to 1, and the length dimension L1 of the buffer slope 215 in the second direction is set to 6 mm. Through experimental verification, the electrode group is not damaged, no liquid leakage is found, and the time requirement of the liquid injection process is not exceeded.

[0051] In Example 6, the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction is set to 3, and the length dimension L1 of the buffer slope 215 in the second direction is set to 6 mm. Through experimental verification, the electrode group is not damaged, no liquid leakage is found, and the time requirement of the liquid injection process is not exceeded.

[0052] In Example 7, the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction is set to 1, and the length dimension L1 of the buffer slope 215 in the second direction is set to 10 mm. Through experimental verification, the electrode group is not damaged, no liquid leakage is found, and the time requirement of the liquid injection process is not exceeded.

[0053] In Example 8, the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction is set to 3, and the length dimension L1 of the buffer slope 215 in the second direction is set to 10 mm. Through experimental verification, the electrode group is not damaged, no liquid leakage is found, and the time requirement of the liquid injection process is not exceeded.

[0054] It can be seen from Examples 1 to 8 that when the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction meets the range of 1 ≤ H1 / H2 ≤ 3, and the length dimension L1 of the buffer slope 215 in the second direction meets the range of 2 mm ≤ L1 ≤ 10 mm, after observation and X-ray detection, it can be known that the electrode group is not damaged during the liquid injection process, no liquid leakage is found during liquid injection, and the time requirement of the liquid injection process is not exceeded.

[0055] In Comparative Example 1, the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction is set to 0.5, and the length dimension L1 of the buffer slope 215 in the second direction is set to 4 mm. Through experimental verification, the electrode group has significant damage, no liquid leakage is found, and the time requirement of the liquid injection process is not exceeded.

[0056] In Comparative Example 2, the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction was set to 0.7, and the length dimension L1 of the buffer inclined surface 215 in the second direction was set to 4 mm. Through experimental verification, the electrode group suffered relatively large damage, no liquid leakage was found, and the time did not exceed the requirements of the liquid injection process.

[0057] It can be seen from Comparative Example 1 to Comparative Example 2 that when the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction is less than the minimum value of the range of 1≤H1 / H2≤3, even if the length dimension L1 of the buffer inclined surface 215 in the second direction meets the range of 2 mm≤L1≤10 mm, but since the bottom surface height of the overflow groove 212 is below the bottom surface of the diversion groove 211 at this time, it has almost no buffering effect on the electrolyte. As a result, after the electrolyte flows out from the overflow hole 214, it still has relatively large energy, so when it flows out, it impacts the electrode group, resulting in relatively large damage to the electrode group.

[0058] In Comparative Example 3, the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction was set to 3.5, and the length dimension L1 of the buffer inclined surface 215 in the second direction was set to 4 mm. Through experimental verification, the electrode group was not damaged, no liquid leakage was found, but the time exceeded the requirements of the liquid injection process.

[0059] In Comparative Example 4, the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction was set to 4, and the length dimension L1 of the buffer inclined surface 215 in the second direction was set to 4 mm. Through experimental verification, the electrode group was not damaged, no liquid leakage was found, but the time exceeded the requirements of the liquid injection process.

[0060] It can be seen from Comparative Example 3 to Comparative Example 4 that when the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction is greater than the maximum value of the range of 1≤H1 / H2≤3, even if the length dimension L1 of the buffer inclined surface 215 in the second direction meets the range of 2 mm≤L1≤10 mm, but due to the excessive height difference between the diversion groove 211 and the overflow groove 212 in the first direction, it is difficult for the electrolyte to enter the overflow groove 212 from the diversion groove 211, resulting in a relatively long time for the electrolyte to enter the overflow groove 212 from the diversion groove 211. Therefore, the time for its liquid injection exceeds the requirements specified by the liquid injection process.

[0061] In Comparative Example 5, the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction was set to 2, and the length dimension L1 of the buffer inclined surface 215 in the second direction was set to 12 mm. After experimental verification, the electrode group was not damaged and no liquid leakage was found, but the time exceeded the requirements of the liquid injection process.

[0062] It can be seen from Comparative Example 5 that when the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction meets the range of 1 ≤ H1 / H2 ≤ 3, but the length dimension L1 of the buffer inclined surface 215 in the second direction is greater than the maximum value of the range of 2 mm ≤ L1 ≤ 10 mm, at this time, due to the large distance between the overflow groove 212 and the diversion groove 211 in the second direction, the flow path of the electrolyte is extended, resulting in the need to consume more time, and thus the liquid injection time exceeds the time required by the liquid injection process. However, due to the extension of its path, the buffering effect on the overflow electrolyte is improved, so the impact on the electrode group is avoided.

[0063] In Comparative Example 6, the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction was set to 2, and the length dimension L1 of the buffer inclined surface 215 in the second direction was set to 1 mm. After experimental verification, the electrode group had slight damage, no liquid leakage was found, and the time did not exceed the requirements of the liquid injection process.

[0064] It can be seen from Comparative Example 6 that when the ratio (H1 / H2) between the depth dimension H1 of the diversion groove 211 in the first direction and the depth dimension H2 of the overflow groove 212 in the first direction meets the range of 1 ≤ H1 / H2 ≤ 3, but the length dimension L1 of the buffer inclined surface 215 in the second direction is less than the minimum value of the range of 2 mm ≤ L1 ≤ 10 mm, at this time, due to the short distance between the overflow groove 212 and the diversion groove 211 in the second direction, the buffering ability of the electrolyte is reduced, resulting in slight damage to the electrode group. Although it is still within the qualified range, compared with the undamaged electrode group, the product quality has decreased. However, due to the short distance between the overflow groove 212 and the diversion groove 211 in the second direction, the flow path of the electrolyte is shortened, thus reducing the time required for liquid injection and avoiding the problem of liquid injection overtime.

[0065] Optionally, the included angle θ between the buffer slope 215 and the extension surface extending from the bottom surface of the diversion groove 211 towards the overflow groove 212 satisfies 15° ≤ θ ≤ 70°. By setting the included angle θ between the buffer slope 215 and the extension surface extending from the bottom surface of the diversion groove 211 towards the overflow groove 212, the inclination degree of the buffer slope 215 is determined. On the one hand, if the included angle θ is too small, the slope of the buffer slope 215 will be too gentle, reducing the buffering effect on the electrolyte. On the other hand, if the included angle θ is too large, the slope of the buffer slope 215 will be too large, increasing the difficulty of the electrolyte overflowing from the diversion groove 211 to the overflow groove 212 and increasing the injection time.

[0066] In this embodiment, the included angle θ between the buffer slope 215 and the extension surface extending from the bottom surface of the diversion groove 211 towards the overflow groove 212 can be any value between 15° and 70° or the range between any two values, such as 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, etc.

[0067] In this embodiment, in order to determine the buffering effect of the included angle θ between the buffer slope 215 and the extension surface extending from the bottom surface of the diversion groove 211 towards the overflow groove 212 on the electrolyte during injection, and the overflow effect of the opened overflow groove 212 communicating with the diversion groove 211 during injection, as shown in Table 2, eight groups of embodiments and four groups of comparative examples are provided for verification, and it is observed whether there is liquid leakage during injection. After the injection is completed, X-ray detection is used to determine whether the electrode group is damaged.

[0068] Table 2

[0069]

[0070] In Embodiment 9, the length dimension L1 of the buffer slope 215 along the second direction is set to 2 mm, and the included angle θ between the buffer slope 215 and the extension surface extending from the bottom surface of the diversion groove 211 towards the overflow groove 212 is set to 15°. After experimental verification, the electrode group is not damaged, no liquid leakage is found, and the injection process requirement time is not exceeded.

[0071] In Embodiment 10, the length dimension L1 of the buffer slope 215 along the second direction is set to 10 mm, and the included angle θ between the buffer slope 215 and the extension surface extending from the bottom surface of the diversion groove 211 towards the overflow groove 212 is set to 15°. After experimental verification, the electrode group is not damaged, no liquid leakage is found, and the injection process requirement time is not exceeded.

[0072] In Example 11, the length dimension L1 of the buffer inclined surface 215 in the second direction is set to 2 mm, and the angle θ between the buffer inclined surface 215 and the extension surface of the bottom surface of the diversion groove 211 extending towards the overflow groove 212 is set to 45°. Through experimental verification, the electrode group is not damaged, no liquid leakage is found, and the time does not exceed the requirements of the liquid injection process.

[0073] In Example 12, the length dimension L1 of the buffer inclined surface 215 in the second direction is set to 10 mm, and the angle θ between the buffer inclined surface 215 and the extension surface of the bottom surface of the diversion groove 211 extending towards the overflow groove 212 is set to 45°. Through experimental verification, the electrode group is not damaged, no liquid leakage is found, and the time does not exceed the requirements of the liquid injection process.

[0074] In Example 13, the length dimension L1 of the buffer inclined surface 215 in the second direction is set to 4 mm, and the angle θ between the buffer inclined surface 215 and the extension surface of the bottom surface of the diversion groove 211 extending towards the overflow groove 212 is set to 45°. Through experimental verification, the electrode group is not damaged, no liquid leakage is found, and the time does not exceed the requirements of the liquid injection process.

[0075] In Example 14, the length dimension L1 of the buffer inclined surface 215 in the second direction is set to 4 mm, and the angle θ between the buffer inclined surface 215 and the extension surface of the bottom surface of the diversion groove 211 extending towards the overflow groove 212 is set to 60°. Through experimental verification, the electrode group is not damaged, no liquid leakage is found, and the time does not exceed the requirements of the liquid injection process.

[0076] In Example 15, the length dimension L1 of the buffer inclined surface 215 in the second direction is set to 2 mm, and the angle θ between the buffer inclined surface 215 and the extension surface of the bottom surface of the diversion groove 211 extending towards the overflow groove 212 is set to 15°. Through experimental verification, the electrode group is not damaged, no liquid leakage is found, and the time does not exceed the requirements of the liquid injection process.

[0077] In Example 16, the length dimension L1 of the buffer inclined surface 215 in the second direction is set to 10 mm, and the angle θ between the buffer inclined surface 215 and the extension surface of the bottom surface of the diversion groove 211 extending towards the overflow groove 212 is set to 75°. Through experimental verification, the electrode group is not damaged, no liquid leakage is found, and the time does not exceed the requirements of the liquid injection process.

[0078] It can be seen from Examples 9 to 16 that on the premise that the length dimension L1 of the buffer inclined surface 215 in the second direction all meets the requirements, different values are taken for the angle θ between the buffer inclined surface 215 and the extension surface of the bottom surface of the diversion groove 211 extending towards the overflow groove 212. When the values of the angle θ all satisfy 15° ≤ θ ≤ 70°, it can be ensured that the inclination degree of the buffer inclined surface 215 meets the requirements, which can not only play a buffering effect on the electrolyte to avoid damage to the electrode group, but also avoid the time consumed by the outflow of the electrolyte being too long and exceeding the time requirements of the liquid injection process.

[0079] In Comparative Example 7, the length dimension L1 of the buffer inclined surface 215 along the second direction is set to 2 mm, and the included angle θ between the buffer inclined surface 215 and the extension surface of the bottom surface of the diversion groove 211 extending towards the overflow groove 212 is set to 10°. Through experimental verification, the electrode group has slight damage, no liquid leakage is found, and the time does not exceed the requirements of the liquid injection process.

[0080] In Comparative Example 8, the length dimension L1 of the buffer inclined surface 215 along the second direction is set to 6 mm, and the included angle θ between the buffer inclined surface 215 and the extension surface of the bottom surface of the diversion groove 211 extending towards the overflow groove 212 is set to 10°. Through experimental verification, the electrode group has slight damage, no liquid leakage is found, and the time does not exceed the requirements of the liquid injection process.

[0081] It can be seen from Comparative Example 7 to Comparative Example 8 that on the premise that the length dimension L1 of the buffer inclined surface 215 along the second direction meets the requirements, different values are taken for the included angle θ between the buffer inclined surface 215 and the extension surface of the bottom surface of the diversion groove 211 extending towards the overflow groove 212. When the value of the included angle θ is less than the minimum value of the range of 15°≤θ≤70°, the inclination degree of the buffer inclined surface 215 is small and the slope is gentle, thus reducing the difficulty of the electrolyte flowing from the diversion groove 211 into the overflow groove 212, weakening the buffering effect on the electrolyte, and resulting in slight damage to the electrode group.

[0082] In Comparative Example 9, the length dimension L1 of the buffer inclined surface 215 along the second direction is set to 2 mm, and the included angle θ between the buffer inclined surface 215 and the extension surface of the bottom surface of the diversion groove 211 extending towards the overflow groove 212 is set to 80°. Through experimental verification, the electrode group is not damaged, no liquid leakage is found, but the time exceeds the requirements of the liquid injection process.

[0083] In Comparative Example 10, the length dimension L1 of the buffer inclined surface 215 along the second direction is set to 6 mm, and the included angle θ between the buffer inclined surface 215 and the extension surface of the bottom surface of the diversion groove 211 extending towards the overflow groove 212 is set to 80°. Through experimental verification, the electrode group is not damaged, no liquid leakage is found, but the time exceeds the requirements of the liquid injection process.

[0084] It can be seen from Comparative Example 9 to Comparative Example 10 that on the premise that the length dimension L1 of the buffer inclined surface 215 along the second direction meets the requirements, different values are taken for the included angle θ between the buffer inclined surface 215 and the extension surface of the bottom surface of the diversion groove 211 extending towards the overflow groove 212. When the value of the included angle θ is greater than the maximum value of the range of 15°≤θ≤70°, the inclination degree of the buffer inclined surface 215 is large and the slope is steep, thus increasing the difficulty of the electrolyte flowing from the diversion groove 211 into the overflow groove 212, prolonging the time for the electrolyte to flow from the diversion groove 211 into the overflow groove 212, resulting in exceeding the time required by the liquid injection process, prolonging the production beat, and reducing the production efficiency.

[0085] Optionally, as shown in Figure 2 and Figure 3 shown, a plurality of diversion holes 213 are formed in the diversion groove 211. The total effective cross-sectional area of the plurality of diversion holes 213 is S1, and the projected area of the diversion groove 211 on the cover body 1 or the outer shell body wall surface along the first direction is S2, and 0.25 ≤ S1 / S2 ≤ 0.6 is satisfied. By setting the total effective cross-sectional area of the plurality of diversion holes 213 as S1, the projected area of the diversion groove 211 on the cover body 1 or the outer shell body wall surface along the first direction as S2, and limiting the ratio between the total effective cross-sectional area S1 of the plurality of diversion holes 213 and the projected area S2 of the diversion groove 211 on the cover body 1 along the first direction, such that the ratio of the two satisfies 0.25 ≤ S1 / S2 ≤ 0.6, on the one hand, it is avoided that the total effective cross-sectional area S1 of the plurality of diversion holes 213 is too small, thereby reducing the flow rate of the electrolyte flowing out of the diversion holes 213, and on the other hand, it is avoided that the total effective cross-sectional area S1 of the plurality of diversion holes 213 is too large, thereby reducing the structural strength of the first insulating structure 2 at the diversion groove 211, such that when the electrolyte accumulates in the diversion groove 211, the first insulating structure 2 deforms at the diversion groove 211.

[0086] In this embodiment, the diversion holes 213 are circular through holes with a hole diameter of d1. The number of diversion holes 213 formed in the diversion groove 211 is N1. Therefore, the total effective cross-sectional area S1 of the plurality of diversion holes 213 = (d1 / 2) 2 ·π·N1.

[0087] Optionally, as shown in Figure 2 and Figure 3 shown, the total effective cross-sectional area of the liquid injection hole 11 is S, and 0.8 ≤ S1 / S ≤ 1.2 is satisfied. By setting the total effective cross-sectional area of the liquid injection hole 11 as S, and limiting the ratio between the total effective cross-sectional area S1 of the plurality of diversion holes 213 and the total effective cross-sectional area S of the liquid injection hole 11, such that the ratio of the two satisfies 0.8 ≤ S1 / S ≤ 1.2, on the one hand, it is avoided that the proportion of the total effective cross-sectional area S1 of the plurality of diversion holes 213 is too small, thereby reducing the flow rate of the electrolyte flowing out of the diversion holes 213, and on the other hand, it is avoided that the proportion of the total effective cross-sectional area S1 of the plurality of diversion holes 213 is too large, thereby causing a large impact on the electrode group after the electrolyte flows out of the diversion holes 213, thereby causing damage to the electrode group.

[0088] In this embodiment, the liquid injection hole 11 is a circular through hole with a hole diameter of d2. Therefore, the effective cross-sectional area S of the liquid injection hole 11 = (d2 / 2) 2 ·π.

[0089] Optionally, as shown in Figure 2 and Figure 3As shown, a plurality of overflow holes 214 are formed in the overflow groove 212. The total effective cross-sectional area of the plurality of overflow holes 214 is S3, and the projected area of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction is S4, and 0.25 ≤ S3 / S4 ≤ 0.6 is satisfied. By setting the total effective cross-sectional area of the plurality of overflow holes 214 as S3 and the projected area of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction as S4, and limiting the ratio of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the projected area S4 of the overflow groove 212 on the cover body 1 in the first direction, the ratio of the two is made to satisfy 0.25 ≤ S3 / S4 ≤ 0.6. Thus, on the one hand, it avoids the total effective cross-sectional area S3 of the plurality of overflow holes 214 being too small, thereby reducing the flow rate of the electrolyte flowing out of the overflow holes 214. On the other hand, it avoids the total effective cross-sectional area S3 of the plurality of overflow holes 214 being too large, thereby reducing the structural strength of the first insulating structure 2 at the overflow groove 212, so that when the electrolyte accumulates in the overflow groove 212, the first insulating structure 2 deforms at the overflow groove 212.

[0090] In this embodiment, the overflow holes 214 are circular through holes with a hole diameter of d3. There are N2 overflow holes 214 formed in the overflow groove 212. Therefore, the total effective cross-sectional area S3 of the plurality of overflow holes 214 = (d3 / 2) 2 ·π·N2.

[0091] Optionally, as Figure 2 、 Figure 3 shown, the total effective cross-sectional area of the liquid injection hole 11 is S, and 0.6 ≤ S3 / S ≤ 1 is satisfied. By setting the total effective cross-sectional area of the liquid injection hole 11 as S and limiting the ratio of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the total effective cross-sectional area S of the liquid injection hole 11, the ratio of the two is made to satisfy 0.6 ≤ S3 / S ≤ 1. Thus, on the one hand, it avoids the total effective cross-sectional area S3 of the plurality of overflow holes 214 having too small a proportion, thereby reducing the flow rate of the electrolyte flowing out of the overflow holes 214. On the other hand, it avoids the total effective cross-sectional area S3 of the plurality of overflow holes 214 having too large a proportion, so that after the electrolyte flows out of the overflow holes 214, it causes a large impact on the electrode group, thereby causing damage to the electrode group.

[0092] In this embodiment, the liquid injection hole 11 is a circular through hole with a hole diameter of d2. Therefore, the effective cross-sectional area S of the liquid injection hole 11 = (d2 / 2) 2 ·π.

[0093] In this embodiment, in order to verify the ratio S1 / S2 between the total effective cross-sectional area S1 of multiple diversion holes 213 and the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction, the ratio S1 / S between the total effective cross-sectional area S1 of multiple diversion holes 213 and the total effective cross-sectional area S of the liquid injection hole 11, the ratio S3 / S4 between the total effective cross-sectional area S3 of multiple overflow holes 214 and the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction, and the ratio S3 / S between the total effective cross-sectional area S3 of multiple overflow holes 214 and the total effective cross-sectional area S of the liquid injection hole 11, the effect of electrolyte buffering during liquid injection, and the effect of overflow during liquid injection of the overflow groove 212 communicated with the diversion groove 211, as shown in Table 3, eight groups of embodiments and six groups of comparative examples are provided for verification, and it is observed whether liquid leakage occurs during liquid injection. After the liquid injection is completed, X-ray detection is used to determine whether the electrode group is damaged.

[0094] Table 3

[0095]

[0096] In Embodiment 17, the ratio S1 / S2 between the total effective cross-sectional area S1 of multiple diversion holes 213 and the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.25, the ratio S1 / S between the total effective cross-sectional area S1 of multiple diversion holes 213 and the total effective cross-sectional area S of the liquid injection hole 11 is set to 0.8, the ratio S3 / S4 between the total effective cross-sectional area S3 of multiple overflow holes 214 and the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.25, and the ratio S3 / S between the total effective cross-sectional area S3 of multiple overflow holes 214 and the total effective cross-sectional area S of the liquid injection hole 11 is set to 0.6. After experimental verification, no damage is found in the electrode group, and no liquid leakage is found either.

[0097] In Embodiment 18, the ratio S1 / S2 between the total effective cross-sectional area S1 of multiple diversion holes 213 and the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.4, the ratio S1 / S between the total effective cross-sectional area S1 of multiple diversion holes 213 and the total effective cross-sectional area S of the liquid injection hole 11 is set to 1, the ratio S3 / S4 between the total effective cross-sectional area S3 of multiple overflow holes 214 and the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.4, and the ratio S3 / S between the total effective cross-sectional area S3 of multiple overflow holes 214 and the total effective cross-sectional area S of the liquid injection hole 11 is set to 0.8. After experimental verification, no damage is found in the electrode group, and no liquid leakage is found either.

[0098] In Embodiment 19, the ratio S1 / S2 of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.6. The ratio S1 / S of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 0.9. The ratio S3 / S4 of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.3. The ratio S3 / S of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 1. After experimental verification, no damage was found in the electrode group, and no liquid leakage was found either.

[0099] In Embodiment 20, the ratio S1 / S2 of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.25. The ratio S1 / S of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 1. The ratio S3 / S4 of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.3. The ratio S3 / S of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 0.8. After experimental verification, no damage was found in the electrode group, and no liquid leakage was found either.

[0100] In Embodiment 21, the ratio S1 / S2 of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.25. The ratio S1 / S of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 0.9. The ratio S3 / S4 of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.6. The ratio S3 / S of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 0.6. After experimental verification, no damage was found in the electrode group, and no liquid leakage was found either.

[0101] In Embodiment 22, the ratio S1 / S2 of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.4. The ratio S1 / S of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 0.8. The ratio S3 / S4 of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.6. The ratio S3 / S of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 1. After experimental verification, no damage was found in the electrode group, and no liquid leakage was found either.

[0102] In Embodiment 23, the ratio S1 / S2 of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.6. The ratio S1 / S of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 1. The ratio S3 / S4 of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.4. The ratio S3 / S of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 0.6. After experimental verification, no damage was found in the electrode group, and no liquid leakage was found either.

[0103] In Embodiment 24, the ratio S1 / S2 of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.6. The ratio S1 / S of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 1.2. The ratio S3 / S4 of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.6. The ratio S3 / S of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 1. After experimental verification, no damage was found in the electrode group, and no liquid leakage was found either.

[0104] As can be seen from Embodiment 17 to Embodiment 24, when the ratio S1 / S2 between the total effective cross-sectional area S1 of the plurality of diversion holes 213 and the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction satisfies the range of 0.25 ≤ S1 / S2 ≤ 0.6, the ratio S1 / S between the total effective cross-sectional area S1 of the plurality of diversion holes 213 and the total effective cross-sectional area S of the liquid injection hole 11 satisfies the range of 0.8 ≤ S1 / S ≤ 1.2, the ratio S3 / S4 between the total effective cross-sectional area S3 of the plurality of overflow holes 214 and the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction satisfies the range of 0.25 ≤ S3 / S4 ≤ 0.6, and the ratio S3 / S between the total effective cross-sectional area S3 of the plurality of overflow holes 214 and the total effective cross-sectional area S of the liquid injection hole 11 satisfies the range of 0.6 ≤ S3 / S ≤ 1, no damage to the electrode group and no liquid leakage are found.

[0105] In Comparative Example 11, the ratio S1 / S2 between the total effective cross-sectional area S1 of the plurality of diversion holes 213 and the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.2, the ratio S1 / S between the total effective cross-sectional area S1 of the plurality of diversion holes 213 and the total effective cross-sectional area S of the liquid injection hole 11 is set to 0.8, the ratio S3 / S4 between the total effective cross-sectional area S3 of the plurality of overflow holes 214 and the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.2, and the ratio S3 / S between the total effective cross-sectional area S3 of the plurality of overflow holes 214 and the total effective cross-sectional area S of the liquid injection hole 11 is set to 0.6. After experimental verification, the electrode group is not damaged, and a small amount of liquid leakage is found.

[0106] As can be seen from Comparative Example 11, by making the ratio S1 / S2 between the total effective cross-sectional area S1 of the plurality of diversion holes 213 and the projected area S2 of the diversion groove 211 on the cover body 1 in the first direction less than the minimum value of the range of 0.25 ≤ S1 / S2 ≤ 0.6, and the ratio S3 / S4 between the total effective cross-sectional area S3 of the plurality of overflow holes 214 and the projected area S4 of the overflow groove 212 on the cover body 1 in the first direction less than the minimum value of the range of 0.25 ≤ S3 / S4 ≤ 0.6, the total effective cross-sectional area S1 of the diversion holes 213 and the total effective cross-sectional area S3 of the overflow holes 214 are made too small, so that the injection speed of the electrolyte is greatly slowed down. Although the protection of the electrode group is improved, due to the slow flow rate, overflow is caused, and a small amount of liquid leakage occurs.

[0107] In Comparative Example 12, the ratio S1 / S2 of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction was set to 0.2. The ratio S1 / S of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the total effective cross-sectional area S of the liquid injection hole 11 was set to 0.6. The ratio S3 / S4 of the total effective cross-sectional area S3 of the plurality of overflow holes 214 and the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction was set to 0.2. The ratio S3 / S of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the total effective cross-sectional area S of the liquid injection hole 11 was set to 0.4. After experimental verification, the electrode group was not damaged, and a large amount of liquid leakage was found.

[0108] It can be seen from Comparative Example 12 that by making the ratio S1 / S2 of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction less than the minimum value of the range 0.25 ≤ S1 / S2 ≤ 0.6, the ratio S1 / S of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the total effective cross-sectional area S of the liquid injection hole 11 less than the minimum value of the range 0.8 ≤ S1 / S ≤ 1.2, the ratio S3 / S4 of the total effective cross-sectional area S3 of the plurality of overflow holes 214 and the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction less than the minimum value of the range 0.25 ≤ S3 / S4 ≤ 0.6, and the ratio S3 / S of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the total effective cross-sectional area S of the liquid injection hole 11 less than the minimum value of the range, not only the total effective cross-sectional area S1 of the diversion holes 213 and the total effective cross-sectional area S3 of the overflow holes 214 are small, but also the flow velocity deviation of the diversion holes 213 and the overflow holes 214 relative to the liquid injection hole 11 is large. As a result, while the outflow velocity of the electrolyte through the diversion holes 213 and the overflow holes 214 is reduced, and because the flow velocity of the diversion holes 213 and the overflow holes 214 is less than the flow velocity of the liquid injection hole 11, the overflow problem becomes more serious, and a large amount of liquid leakage occurs.

[0109] In Comparative Example 13, the ratio S1 / S2 of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.8. The ratio S1 / S of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 1.2. The ratio S3 / S4 of the total effective cross-sectional area S3 of the plurality of overflow holes 214 and the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.6. The ratio S3 / S of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 1.2. After experimental verification, damage was found in the electrode group, and no liquid leakage was found.

[0110] It can be seen from Comparative Example 13 that when the ratio of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the projected area S2 of the diversion groove 211 on the cover body 1 in the first direction is greater than the maximum value of 0.25≤S1 / S2≤0.6 and the ratio of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the total effective cross-sectional area S of the liquid injection hole 11 is greater than the maximum value of 0.6≤S3 / S≤1, it can be known that the total effective area S1 of the diversion holes 213 is too large. Therefore, the flow velocity at the diversion holes 213 is relatively large, and the outflow velocity of the overflow holes 214 is greater than the inflow velocity of the liquid injection hole 11. Therefore, the overflow holes 214 cannot play a buffering effect through the hole diameter. Combining the above two points, the outflow velocity of the electrolyte through the overflow holes 214 and the diversion holes 213 is relatively fast, which has a certain impact on the electrode group and causes damage to the electrode group.

[0111] In Comparative Example 14, the ratio S1 / S2 of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.6. The ratio S1 / S of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 1.2. The ratio S3 / S4 of the total effective cross-sectional area S3 of the plurality of overflow holes 214 and the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.8. The ratio S3 / S of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 1. After experimental verification, damage was found in the electrode group, and no liquid leakage was found.

[0112] It can be seen from Comparative Example 14 that when the ratio S3 / S4 of the total effective cross-sectional area S3 of the plurality of overflow holes 214 and the projected area S4 of the overflow groove 212 on the cover body 1 in the first direction is greater than the maximum value of 0.25≤S3 / S4≤0.6, it can be known that the total effective area S3 of the overflow holes 214 is too large. Therefore, the flow velocity at the overflow holes 214 is relatively large, which has a certain impact on the electrode group and causes damage to the electrode group.

[0113] In Comparative Example 15, the ratio S1 / S2 of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.4, the ratio S1 / S of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 1, the ratio S3 / S4 of the total effective cross-sectional area S3 of the plurality of overflow holes 214 and the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.8, and the ratio S3 / S of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 1.2. After experimental verification, damage was found in the electrode group, and no liquid leakage was found.

[0114] It can be seen from Comparative Example 15 that when the ratio S3 / S4 of the total effective cross-sectional area S3 of the plurality of overflow holes 214 and the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction is greater than the maximum value of 0.25 ≤ S3 / S4 ≤ 0.6, it can be known that the total effective area S3 of the overflow holes 214 is too large. Therefore, the flow velocity at the overflow holes 214 is relatively large, which has a certain impact on the electrode group, and the outflow velocity of the overflow holes 214 is greater than the inflow velocity of the liquid injection hole 11. Therefore, the overflow holes 214 cannot play a buffering effect through the aperture. Combining the above two points, the flow velocity of the electrolyte flowing out through the overflow holes 214 and the diversion holes 213 is relatively fast, which also has a certain impact on the electrode group. The combination of the two causes damage to the electrode group during the liquid injection process.

[0115] In Comparative Example 16, the ratio S1 / S2 of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.8, the ratio S1 / S of the total effective cross-sectional area S1 of the plurality of diversion holes 213 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 1.2, the ratio S3 / S4 of the total effective cross-sectional area S3 of the plurality of overflow holes 214 and the projected area S4 of the overflow groove 212 on the cover body 1 or the outer shell body wall surface in the first direction is set to 0.6, and the ratio S3 / S of the total effective cross-sectional area S3 of the plurality of overflow holes 214 to the total effective cross-sectional area S of the liquid injection hole 11 is set to 1. After experimental verification, damage was found in the electrode group, and no liquid leakage was found.

[0116] As can be seen from Comparative Example 16, when the ratio between the total effective cross-sectional area S1 of the plurality of diversion holes 213 and the projected area S2 of the diversion groove 211 on the cover body 1 or the outer shell body wall surface in the first direction is greater than the maximum value of 0.25 ≤ S1 / S2 ≤ 0.6, it can be known that the total effective area S1 of the diversion holes 213 is too large. Therefore, the flow velocity at the diversion holes 213 is relatively large, which has a certain impact on the electrode group, causing damage to the electrode group during the liquid injection process.

[0117] Optionally, as Figure 2 shown, the distance dimension L2 in the second direction between the boundary of the one overflow hole 214 closest to the tab 100 among the plurality of overflow holes 214 and the tab 100 satisfies L2 ≥ 1 mm. By setting the distance dimension L2 between the boundary of the one overflow hole 214 closest to the tab 100 among the plurality of overflow holes 214 and the tab 100, and limiting the distance dimension L2 between the boundary of the one overflow hole 214 closest to the tab 100 among the plurality of overflow holes 214 and the tab 100 to satisfy L2 ≥ 1 mm, a certain distance is ensured between the tab 100 and the overflow hole 214, avoiding the impact on the tab 100 when the electrolyte flows out of the overflow hole 214, thereby causing damage to the tab 100.

[0118] Optionally, as Figure 3 shown, the diversion hole 213 is a circular through-hole, an oval through-hole or a polygonal through-hole. By selecting various types of through-holes as the diversion hole 213, it is convenient to freely choose according to actual needs during production.

[0119] Optionally, as Figure 3 shown, the overflow hole 214 is a circular through-hole, an oval through-hole or a polygonal through-hole. By selecting various types of through-holes as the overflow hole 214, it is convenient to freely choose according to actual needs during production.

[0120] Optionally, the first insulating structural member 2 is a plastic part integrally formed by an injection molding process. By using a plastic part integrally formed by an injection molding process as the first insulating structural member 2, on the one hand, the insulation of the first insulating structural member 2 is ensured, and on the other hand, it is convenient to form the liquid injection structure 21 composed of the diversion groove 211 and the overflow groove 212 on the first insulating structural member 2 during production.

[0121] In this embodiment, a battery is further provided. The battery includes an electrode group and the above-mentioned battery housing, and the electrode group is accommodated in the battery housing. By applying the above-mentioned battery housing, the battery not only improves the use safety due to its lower risk of insulation failure, but also improves the product quality by reducing the damage to the electrode group during the production process.

[0122] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. Battery housing, characterized in that, The battery housing includes a cover body, a housing body, and a first insulating structure. The housing body is a hollow shell structure with an opening, and the cover body is disposed at the opening of the housing body to form a receiving cavity for accommodating the electrode group. A liquid injection hole is formed on the wall surface of the cover body or the housing body opposite to the side where the electrode group extends the tab. The first insulating structure is located in the receiving cavity and is disposed on the side where the electrode group extends the tab. A liquid injection structure is provided on one side of the first insulating structure opposite to the liquid injection hole. The liquid injection structure includes a diversion groove and an overflow groove that communicate with each other. The diversion groove covers the liquid injection hole in the projection on the wall surface of the cover body or the housing body along a first direction, and a diversion hole penetrating the diversion groove is formed. An overflow hole penetrating the overflow groove is formed on the overflow groove. The depth dimension of the diversion groove along the first direction is H1, and the depth dimension of the overflow groove along the first direction is H2, and 1≤H1 / H2≤3 is satisfied. A plurality of the diversion holes are formed on the diversion groove. The total effective cross-sectional area of the plurality of diversion holes is S1, and the projected area of the diversion groove on the wall surface of the cover body or the housing body along the first direction is S2, and 0.25≤S1 / S2≤0.6 is satisfied.

2. The battery housing according to claim 1, characterized in that, A buffer inclined surface is provided between the diversion groove and the overflow groove. The length dimension of the buffer inclined surface along a second direction is L1, and 2mm≤L1≤10mm is satisfied.

3. The battery housing according to claim 2, characterized in that, The included angle between the buffer inclined surface and the extension surface extending from the bottom surface of the diversion groove towards the overflow groove is θ, and 15°≤θ≤70° is satisfied.

4. The battery housing according to claim 1, wherein, The total effective cross-sectional area of the liquid injection hole for electrolyte flow is S, and 0.8≤S1 / S≤1.2 is satisfied.

5. The battery housing according to claim 1, characterized in that, A plurality of the overflow holes are formed on the overflow groove. The total effective cross-sectional area of the plurality of overflow holes is S3, and the projected area of the overflow groove on the wall surface of the cover body or the housing body along the first direction is S4, and 0.25≤S3 / S4≤0.6 is satisfied.

6. The battery housing according to claim 5, characterized in that, The total effective cross-sectional area of the liquid injection hole is S, and 0.6≤S3 / S≤1 is satisfied.

7. The battery housing according to claim 5, characterized in that, The distance dimension along the second direction between the boundary of the overflow hole closest to the tab among the plurality of overflow holes and the tab is L2, and L2≥1mm is satisfied.

8. The battery housing according to claim 1, characterized in that, The first insulating structure is a plastic part integrally formed by an injection molding process.

9. A battery, characterized in that, The battery includes an electrode group and the battery housing according to any one of claims 1-8, and the electrode group is accommodated in the battery housing.

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