Battery shell and battery

Abstract

The invention belongs to the technical field of batteries, and discloses a battery shell and a battery, the battery shell comprises a cover plate body, a shell body and an insulating structural member, and a liquid injection hole is formed in the wall surface, opposite to a tab of a pole group, of the cover plate body or the shell body; the liquid injection groove in the insulating structural member comprises a first wall face provided with a first liquid injection channel and a second wall face provided with a second liquid injection channel, the effective sectional area of the first liquid injection channel is S1, the effective sectional area of the second liquid injection channel is S2, the effective sectional area of the liquid injection hole is S, the effective sectional area S1 of the first liquid injection channel is smaller than the effective sectional area S of the liquid injection hole, and the effective sectional area S of the second liquid injection channel is smaller than the effective sectional area S of the liquid injection hole. And 1 < = (S1 + S2) / S < = 1.5. The electrolyte can flow out through the second liquid injection channel when the first liquid injection channel cannot meet the flowing-out speed of the electrolyte and the electrolyte is about to overflow in the liquid injection process, so that the electrolyte can be buffered, and the problem of insulation failure caused by electrolyte overflow is avoided.

Description

Technical Field

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

[0002] Lithium-ion batteries are currently widely used in various fields such as transportation power sources, power energy storage 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, electrolyte, cover plate, housing, internal and external insulation structures, etc. Among them, the cover plate and the housing are usually fixed by laser welding to form a sealed space that protects the pole group with a certain structural strength. 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 arranged on the cover plate, and a through hole communicating with the liquid injection hole is opened on the internal insulation structure, so as to facilitate the inflow of the electrolyte to achieve the purpose of infiltrating the pole group.

[0003] In order to accelerate the flow rate of the electrolyte into the interior, the liquid injection hole on the cover plate and the through hole on the internal insulation structure are concentrically arranged, and the effective cross-sectional area of the through hole for the flow of the electrolyte is larger than the effective cross-sectional area of the liquid injection hole for the flow of the electrolyte, so that when the electrolyte enters the through hole from the liquid injection hole, there will be no obstruction, thereby improving the injection speed. However, since the structure of the pole group is relatively fragile, during the injection operation of the electrolyte under this structure, the pole group is often damaged. Therefore, by changing the aperture of the through hole on the internal insulation part to be smaller than the aperture of the liquid injection hole, it plays a role in alleviating the impact of the electrolyte flowing out from the liquid injection hole.

[0004] However, the aperture of the through hole on the internal insulation part is smaller than the aperture of the liquid injection hole. Although it effectively alleviates the impact of the electrolyte on the pole group, since the flow rate of the electrolyte injected through the liquid injection hole is greater than the flow rate of the electrolyte flowing out through the through hole, 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 reliability. Summary of the Invention

[0005] The purpose of the present invention is to provide a battery housing and a battery with a low risk of insulation failure and good reliability.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] On the one hand, a battery housing is provided. The battery housing includes a cover body, a housing body, and an insulating structural member. The housing body is a hollow shell structure with an opening. The cover body is disposed at the opening of the housing body to form a receiving cavity for accommodating a pole group. A liquid injection hole is formed on the wall surface of the cover body or the housing body opposite to the pole ear of the pole group. The insulating structural member is located in the receiving cavity and is disposed on one side of the pole group where the pole ear extends;

[0008] The insulating structural member includes a first surface, a second surface, and a liquid injection groove. The liquid injection groove is recessed from the first surface to the second surface and protrudes from the second surface. The liquid injection hole is located within the projection of the liquid injection groove on the cover body along a first direction. The liquid injection groove includes a first wall surface and a second wall surface. A first liquid injection channel is formed on the first wall surface, and a second liquid injection channel is formed on the second wall surface;

[0009] The effective cross-sectional area of the first liquid injection channel is S1, the effective cross-sectional area of the second liquid injection channel is S2, and the effective cross-sectional area of the liquid injection hole is S. The effective cross-sectional area S1 of the first liquid injection channel is less than the effective cross-sectional area S of the liquid injection hole, and 1≤(S1 + S2) / S≤1.5 is satisfied.

[0010] Optionally, the thickness dimension of the first wall surface is t1, and 0.5mm≤t1≤3mm is satisfied.

[0011] Optionally, the thickness dimension of the second wall surface is t2, and 0.5mm≤t2≤3mm is satisfied.

[0012] Optionally, the liquid injection hole includes a drainage hole section and an injection hole section. The drainage hole section is located on the side of the cover body away from the insulating structural member, and the injection hole section is located on the side of the cover body facing the insulating structural member. The aperture of the drainage hole section is larger than the aperture of the injection hole section, and a buffer step surface is formed between the drainage hole section and the injection hole section. The effective cross-sectional area of the injection hole section is used to constitute the effective cross-sectional area S of the liquid injection hole.

[0013] Optionally, the average aperture of the drainage hole section is D1, the average aperture of the injection hole section is D2, and 1.2≤D1 / D2≤3 is satisfied. The effective cross-sectional area S of the liquid injection hole =(D2 / 2) 2 ·π.

[0014] Optionally, the drainage hole section is a trumpet shape with an inner diameter gradually decreasing towards the injection hole section.

[0015] Optionally, a plugging boss inserted into the liquid injection groove is further provided on the side of the cover body facing the insulating structural member, and the injection hole section is formed on the plugging boss.

[0016] Optionally, the thickness dimension of the cover plate body is H, and the distance between the buffer step surface and the surface of the plug-in boss facing the insulating structural member is H1, and 0.6 mm ≤ H1 ≤ H is satisfied.

[0017] Optionally, the insulating structural member is a plastic part integrally formed by an injection molding process.

[0018] On the other hand, a battery is provided, and the battery includes a pole group and the battery housing as described in any one of the above, and the pole group is accommodated in the battery housing.

[0019] Advantages of the present invention:

[0020] The present invention provides a battery housing. In this battery housing, a liquid injection groove that is recessed from a first surface to a second surface and protrudes from the second surface is formed in the insulating structural member, a first liquid injection channel is opened on a first wall surface of the liquid injection groove, a second liquid injection channel is opened on a second wall surface of the liquid injection groove, and the relationship among the effective cross-sectional area S1 of the first liquid injection channel, the effective cross-sectional area S2 of the second liquid injection channel, and the effective cross-sectional area S of the liquid injection hole is defined. When the effective cross-sectional area S1 of the first liquid injection channel is less than the effective cross-sectional area S of the liquid injection hole, the three satisfy 1 ≤ (S1 + S2) / S ≤ 1.5. Thus, when the first liquid injection channel cannot meet the outflow speed of the electrolyte and is about to overflow in order to buffer the electrolyte, the electrolyte can flow out smoothly through the second liquid injection channel. Therefore, both the buffering of the electrolyte and the smooth outflow of the electrolyte are ensured, the problem of insulation failure caused by the overflow of the electrolyte is avoided, the risk of insulation failure is reduced, and the reliability of the structure is improved.

[0021] The present invention also provides a battery. By applying the above battery housing, the risk of insulation failure is effectively reduced, the yield of the product is improved, and the manufacturing cost is reduced. Description of the Drawings

[0022] Figure 1 is an assembly drawing of the cover plate body and the insulating structural member in the battery housing provided by the present invention;

[0023] Figure 2 is a structural cross-sectional view in which the liquid injection hole and the first liquid injection channel are coaxial in the battery housing provided by the present invention;

[0024] Figure 3 is a structural cross-sectional view in which the liquid injection hole is not coaxial with the first liquid injection channel in the battery housing provided by the present invention.

[0025] In the figure:

[0026] 1. Cover body; 11. Liquid injection hole; 111. Drainage hole section; 112. Injection hole section; 113. Buffer step surface; 12. Insertion boss;

[0027] 2. Insulating structural member; 21. First surface; 22. Second surface; 23. Liquid injection groove; 231. First wall surface; 232. Second wall surface; 233. First liquid injection channel; 234. Second liquid injection channel. Specific embodiments

[0028] The present invention will be further described in detail below with reference to the accompanying 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 sake of description, only parts related to the present invention are shown in the drawings, rather than all the structures.

[0029] 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 communication between two elements or the interaction relationship between two elements. 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.

[0030] 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 between 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", "above", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "below", "below", and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0031] 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, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element 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 have no special meanings.

[0032] At present, in order to alleviate the impact of the electrolyte on the electrode group, the aperture of the through hole in the inner insulating member is usually made smaller than the aperture of the liquid injection hole in the cover body, resulting in the flow rate of the electrolyte injected through the liquid injection hole being greater than the flow rate of the electrolyte flowing out through the through hole. As a result, the electrolyte cannot flow out through the through hole in time, causing the overflow of the electrolyte and having a high risk of insulation failure.

[0033] Therefore, in order to buffer the electrolyte while avoiding the overflow of the electrolyte, reducing the risk of insulation failure, and improving the reliability of the structure, this embodiment provides a battery housing.

[0034] As Figures 1 to 2 shown, the battery housing includes a cover body 1, a housing body, and an insulating structure member 2. The housing body is a hollow shell structure with an open end. The cover body 1 is provided at the open end of the housing 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 housing body opposite to the electrode tab of the electrode group. The insulating structure member 2 is located in the receiving cavity and is provided on the side where the electrode group extends out the electrode tab. The insulating structure member 2 includes a first surface 21, a second surface 22, and a liquid injection groove 23. The liquid injection groove 23 is recessed from the first surface 21 towards the second surface 22 and protrudes from the second surface 22. The liquid injection hole 11 is located within the projection of the liquid injection groove 23 along the first direction. The liquid injection groove 23 includes a first wall surface 231 and a second wall surface 232. A first liquid injection channel 233 is formed on the first wall surface 231, and a second liquid injection channel 234 is formed on the second wall surface 232. The effective cross-sectional area of the first liquid injection channel 233 is S1, the effective cross-sectional area of the second liquid injection channel 234 is S2, and the effective cross-sectional area of the liquid injection hole 11 is S. The effective cross-sectional area S1 of the first liquid injection channel 233 is smaller than the effective cross-sectional area S of the liquid injection hole 11, and 1 ≤ (S1 + S2) / S ≤ 1.5 is satisfied.

[0035] The battery housing forms a liquid injection groove 23 that is recessed from the first surface 21 to the second surface 22 and protrudes from the second surface 22 on the insulating structural member 2. A first liquid injection channel 233 is opened on the first wall surface 231 of the liquid injection groove 23, and a second liquid injection channel 234 is opened on the second wall surface 232 of the liquid injection groove 23. The relationship among the effective cross-sectional area S1 of the first liquid injection channel 233, the effective cross-sectional area S2 of the second liquid injection channel 234, and the effective cross-sectional area S of the liquid injection hole 11 is defined. On the premise that the effective cross-sectional area S1 of the first liquid injection channel 233 is smaller than the effective cross-sectional area S of the liquid injection hole 11, the three satisfy 1 ≤ (S1 + S2) / S ≤ 1.5. Thus, when the first liquid injection channel 233 cannot meet the outflow speed of the electrolyte and is about to overflow in order to buffer the electrolyte, the electrolyte can flow out smoothly through the second liquid injection channel 234. This not only ensures the buffering of the electrolyte but also ensures the smooth outflow of the electrolyte, avoiding the problem of insulation failure caused by the overflow of the electrolyte, thereby reducing the risk of insulation failure and improving the reliability of the structure.

[0036] In this embodiment, both the first liquid injection channel 233 opened on the first wall surface 231 and the second liquid injection channel 234 opened on the second wall surface 232 are multiple through-holes respectively penetrating the first wall surface 231 and the second wall surface 232. It is set that n1 through-holes constitute the first liquid injection channel 233, and the aperture of each through-hole is d1. Then the effective cross-sectional area S1 of the first liquid injection channel 233 = (d1 / 2) 2 ·π·n1. It is set that n2 through-holes constitute the second liquid injection channel 234, and the aperture of each through-hole is d2. Then the effective cross-sectional area S2 of the second liquid injection channel 234 = (d2 / 2) 2 ·π·n2; The number of through-holes constituting the first liquid injection channel 233 and the number of through-holes constituting the second liquid injection channel 234 can be the same or different. For example, Figure 2 as shown, in this embodiment, the first liquid injection channel 233 is a through-hole that is coaxial with the liquid injection hole 11 and penetrates the first wall surface 231, and the second liquid injection channel 234 is composed of four through-holes evenly distributed on the second wall surface 232. Among them, the shape of the liquid injection groove 23 can be set according to actual needs, such as a circular groove, an oval groove, or a polygonal groove. In this embodiment, the liquid injection groove 23 adopts a circular groove. In addition, this battery housing can be applied to different battery types, such as blade batteries, square shell batteries, large cylindrical batteries, etc.

[0037] In other embodiments, such as Figure 3 shown, the first liquid injection channel 233 is composed of multiple through-holes penetrating the first wall surface 231. At this time, the through-holes constituting the first liquid injection channel 233 are staggered with the liquid injection hole 11.

[0038] In this embodiment, in order to verify the influence of the dimensional settings of the effective cross-sectional area S1 of the first liquid injection channel 233, the effective cross-sectional area S2 of the second liquid injection channel 234, and the effective cross-sectional area S of the liquid injection hole 11 on liquid injection, as shown in Table 1, fourteen sets of embodiments and five sets of comparative examples are provided for verification, and it is observed whether liquid leakage occurs at the liquid injection hole 11 during liquid injection. After the liquid injection is completed, X-ray detection is used to determine whether the electrode group is damaged.

[0039] Table 1

[0040]

[0041] In Embodiment 1, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 3 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 4 mm 2 , and the effective cross-sectional area S of the liquid injection hole 11 is set to 7 mm 2 . At this time, it can be known that the value of the relational expression (S1 + S2) / S is 1. After experimental verification, the electrode group is not damaged and no liquid leakage is found at the liquid injection hole 11.

[0042] In Embodiment 2, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 0 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 7 mm 2 , and the effective cross-sectional area S of the liquid injection hole 11 is set to 7 mm 2 . At this time, it can be known that the value of the relational expression (S1 + S2) / S is 1. After experimental verification, the electrode group is not damaged and no liquid leakage is found at the liquid injection hole 11.

[0043] In Embodiment 3, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 10 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 10 mm 2 , and the effective cross-sectional area S of the liquid injection hole 11 is set to 20 mm 2 . At this time, it can be known that the value of the relational expression (S1 + S2) / S is 1. After experimental verification, the electrode group is not damaged and no liquid leakage is found at the liquid injection hole 11.

[0044] In Embodiment 4, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 15 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 10 mm 2 , and the effective cross-sectional area S of the liquid injection hole 11 is set to 25 mm 2 . At this time, it can be known that the value of the relational expression (S1 + S2) / S is 1. After experimental verification, the electrode group is not damaged and no liquid leakage is found at the liquid injection hole 11.

[0045] In Example 5, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 4 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 3.7 mm 2 , the effective cross-sectional area S of the liquid injection hole 11 is set to 7 mm 2 , at this time, it can be known that the value of the relational expression (S1 + S2) / S is 1.1. After experimental verification, the electrode group is not damaged and no liquid leakage is found at the liquid injection hole 11.

[0046] In Example 6, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 18 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 15 mm 2 , the effective cross-sectional area S of the liquid injection hole 11 is set to 30 mm 2 , at this time, it can be known that the value of the relational expression (S1 + S2) / S is 1.1. After experimental verification, the electrode group is not damaged and no liquid leakage is found at the liquid injection hole 11.

[0047] In Example 7, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 4 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 4.4 mm 2 , the effective cross-sectional area S of the liquid injection hole 11 is set to 7 mm 2 , at this time, it can be known that the value of the relational expression (S1 + S2) / S is 1.2. After experimental verification, the electrode group is not damaged and no liquid leakage is found at the liquid injection hole 11.

[0048] In Example 8, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 25 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 17 mm 2 , the effective cross-sectional area S of the liquid injection hole 11 is set to 35 mm 2 , at this time, it can be known that the value of the relational expression (S1 + S2) / S is 1.2. After experimental verification, the electrode group is not damaged and no liquid leakage is found at the liquid injection hole 11.

[0049] In Example 9, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 3 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 6 mm 2 , the effective cross-sectional area S of the liquid injection hole 11 is set to 7 mm 2 , at this time, it can be known that the value of the relational expression (S1 + S2) / S is 1.29. After experimental verification, the electrode group is not damaged and no liquid leakage is found at the liquid injection hole 11.

[0050] In Example 10, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 5 mm 2, the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 2.8 mm 2 , the effective cross-sectional area S of the liquid injection hole 11 is set to 6 mm 2 , at this time, it can be known that the value of the relational expression (S1 + S2) / S is 1.3. After experimental verification, the electrode group is not damaged, and no liquid leakage is found in the liquid injection hole 11.

[0051] In Embodiment 11, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 7 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 6 mm 2 , the effective cross-sectional area S of the liquid injection hole 11 is set to 10 mm 2 , at this time, it can be known that the value of the relational expression (S1 + S2) / S is 1.3. After experimental verification, the electrode group is not damaged, and no liquid leakage is found in the liquid injection hole 11.

[0052] In Embodiment 12, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 5 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 4.8 mm 2 , the effective cross-sectional area S of the liquid injection hole 11 is set to 7 mm 2 , at this time, it can be known that the value of the relational expression (S1 + S2) / S is 1.4. After experimental verification, the electrode group is not damaged, and no liquid leakage is found in the liquid injection hole 11.

[0053] In Embodiment 13, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 6 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 4.5 mm 2 , the effective cross-sectional area S of the liquid injection hole 11 is set to 7 mm 2 , at this time, it can be known that the value of the relational expression (S1 + S2) / S is 1.5. After experimental verification, the electrode group is not damaged, and no liquid leakage is found in the liquid injection hole 11.

[0054] In Embodiment 14, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 0 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 30 mm 2 , the effective cross-sectional area S of the liquid injection hole 11 is set to 20 mm 2 , at this time, it can be known that the value of the relational expression (S1 + S2) / S is 1.5. After experimental verification, the electrode group is not damaged, and no liquid leakage is found in the liquid injection hole 11.

[0055] As can be seen from Examples 1 to 14, when the relationship value among the effective cross-sectional area S1 of the first liquid injection channel 233, the effective cross-sectional area S2 of the second liquid injection channel 234, and the effective cross-sectional area S of the liquid injection hole 11 satisfies the range of 1 ≤ (S1 + S2) / S ≤ 1.5, the smooth outflow of the electrolyte can be ensured without damaging the electrode group, thereby avoiding the problem of insulation failure caused by the overflow of the electrolyte.

[0056] In Comparative Example 1, the effective cross-sectional area S1 of the first liquid injection channel 233 was set to 2 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 was set to 3 mm 2 , and the effective cross-sectional area S of the liquid injection hole 11 was set to 7 mm 2 . At this time, it can be known that the value of the relational expression (S1 + S2) / S is 0.71. After experimental verification, the electrode group was not damaged, but liquid leakage was found at the liquid injection hole 11.

[0057] In Comparative Example 2, the effective cross-sectional area S1 of the first liquid injection channel 233 was set to 13 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 was set to 9 mm 2 , and the effective cross-sectional area S of the liquid injection hole 11 was set to 28 mm 2 . At this time, it can be known that the value of the relational expression (S1 + S2) / S is 0.8. After experimental verification, the electrode group was not damaged, but liquid leakage was found at the liquid injection hole 11.

[0058] In Comparative Example 3, the effective cross-sectional area S1 of the first liquid injection channel 233 was set to 16 mm 2 , the effective cross-sectional area S2 of the second liquid injection channel 234 was set to 12 mm 2 , and the effective cross-sectional area S of the liquid injection hole 11 was set to 32 mm 2 . At this time, it can be known that the value of the relational expression (S1 + S2) / S is 0.9. After experimental verification, the electrode group was not damaged, but liquid leakage was found at the liquid injection hole 11.

[0059] As can be seen from Comparative Example 1 to Comparative Example 3, when the relationship value among the effective cross-sectional area S1 of the first liquid injection channel 233, the effective cross-sectional area S2 of the second liquid injection channel 234, and the effective cross-sectional area S of the liquid injection hole 11 is less than the minimum value of the range of 1 ≤ (S1 + S2) / S ≤ 1.5, the sum of the effective cross-sectional areas of the first liquid injection channel 233 and the second liquid injection channel 234 is too small at this time, resulting in the flow rate of the electrolyte injected through the liquid injection hole 11 being greater than the flow rate of the electrolyte flowing out through the first liquid injection channel 233 and the second liquid injection channel 234. Although the buffer effect on the electrolyte is achieved and the impact on the electrode group is reduced, the electrolyte overflows, resulting in liquid leakage being found at the liquid injection hole 11 and causing the problem of insulation failure.

[0060] In Comparative Example 4, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 33 mm 2 and the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 21.4 mm 2 and the effective cross-sectional area S of the liquid injection hole 11 is set to 34 mm 2 At this time, it can be known that the value of the relationship formula (S1 + S2) / S is 1.6. After experimental verification, no liquid leakage is found in the liquid injection hole 11, the electrode group is damaged, and the insulating structural member 2 is deformed.

[0061] In Comparative Example 5, the effective cross-sectional area S1 of the first liquid injection channel 233 is set to 20 mm 2 and the effective cross-sectional area S2 of the second liquid injection channel 234 is set to 32 mm 2 and the effective cross-sectional area S of the liquid injection hole 11 is set to 26 mm 2 At this time, it can be known that the value of the relationship formula (S1 + S2) / S is 2. After experimental verification, no liquid leakage is found in the liquid injection hole 11, the electrode group is damaged, and the insulating structural member 2 is deformed.

[0062] It can be seen from Comparative Example 4 to Comparative Example 5 that when the relationship value of the effective cross-sectional area S1 of the first liquid injection channel 233, the effective cross-sectional area S2 of the second liquid injection channel 234, and the effective cross-sectional area S of the liquid injection hole 11 is greater than the maximum value of the range of 1 ≤ (S1 + S2) / S ≤ 1.5, at this time, the sum of the effective cross-sectional areas of the first liquid injection channel 233 and the second liquid injection channel 234 is too large. Although the flow rate of the electrolyte flowing out through the first liquid injection channel 233 and the second liquid injection channel 234 is greater than the flow rate of the electrolyte injected through the liquid injection hole 11, ensuring the smooth outflow of the electrolyte and avoiding the problem of insulation failure caused by electrolyte overflow, the remaining material of the liquid injection groove 23 is less, resulting in a smaller structural strength at the liquid injection groove 23. As a result, after the electrolyte flows out of the liquid injection hole 11, it impacts the liquid injection groove 23, causing the liquid injection groove 23 to deform, changing the effective cross-sectional area of the first liquid injection channel 233 for electrolyte flow, and causing the electrolyte to impact the electrode group, resulting in damage to the electrode group.

[0063] Optionally, as Figure 2 shown, the thickness dimension of the first wall surface 231 is t1, and it satisfies 0.5 mm ≤ t1 ≤ 3 mm. By setting the thickness dimension of the first wall surface 231 as t1 and limiting the thickness dimension t1 of the first wall surface 231 to satisfy 0.5 mm ≤ t1 ≤ 3 mm, on the one hand, it avoids the too thin thickness of the first wall surface 231 and the lower structural strength, resulting in deformation when bearing the impact of the electrolyte, and on the other hand, it avoids the too thick thickness of the first wall surface 231, thereby increasing the material consumption and raising the manufacturing cost.

[0064] In this embodiment, the thickness dimension t1 of the first wall surface 231 can be any value between 0.5 mm and 3 mm or a range between any two values, such as 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, etc.

[0065] Alternatively, if Figure 2 As shown, the thickness dimension of the second wall 232 is t2, and satisfies 0.5mm≤t2≤3mm. By setting the thickness dimension of the second wall 232 to t2, and limiting the thickness dimension t2 of the second wall 232 to satisfy 0.5mm≤t2≤3mm, on the one hand, it is avoided that the thickness of the second wall 232 is too thin, the structural strength is low, and thus deformation occurs when bearing the impact of the electrolyte, and on the other hand, it is avoided that the thickness of the second wall 232 is too thick, thereby increasing the material consumption and the manufacturing cost.

[0066] In this embodiment, the thickness dimension t2 of the second wall surface 232 can be any value between 0.5 mm and 3 mm or a range between any two values, such as 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, etc.

[0067] Alternatively, if Figure 2 As shown, the injection hole 11 includes a drainage hole section 111 and an injection hole section 112. The drainage hole section 111 is located on the side of the cover body 1 away from the insulating structure 2, and the injection hole section 112 is located on the side of the cover body 1 facing the insulating structure 2. The aperture of the drainage hole section 111 is larger than the aperture of the injection hole section 112, and a buffer step surface 113 is formed between the drainage hole section 111 and the injection hole section 112. The effective cross-sectional area of ​​the injection hole section 112 is used to constitute the effective cross-sectional area S of the injection hole 11. By making the aperture of the drainage hole section 111 larger than the aperture of the injection hole section 112, a buffer step surface 113 is formed between the drainage hole section 111 and the injection hole section 112, so that when the electrolyte is injected, the buffer step surface 113 is used to buffer the electrolyte, reduce the impact of the electrolyte when it flows out of the cover body 1, and improve the protection performance of the electrode group.

[0068] Alternatively, if Figure 2 As shown, the average pore size of the drainage hole section 111 is D1, the average pore size of the injection hole section 112 is D2, and they satisfy 1.2≤D1 / D2≤3, and the effective cross-sectional area S of the injection hole 11 is (D2 / 2) 2·π. By setting the average pore diameter of the drainage hole section 111 as D1 and the average pore diameter of the injection hole section 112 as D2, and limiting the ratio of the average pore diameter D1 of the drainage hole section 111 to the average pore diameter D2 of the injection hole section 112 to satisfy 1.2 ≤ D1 / D2 ≤ 3, on the one hand, it is avoided that the area of the buffer step surface 113 between the drainage hole section 111 and the injection hole section 112 is too small, resulting in limited buffering capacity. On the other hand, it is avoided that the area of the buffer step surface 113 between the drainage hole section 111 and the injection hole section 112 is too large, thereby limiting the average pore diameter D2 of the injection hole section 112 and reducing the outflow rate of the electrolyte through the injection hole section 112.

[0069] In this embodiment, in order to verify the influence of the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 on the liquid injection, as shown in Table 2, ten sets of embodiments and two sets of comparative examples are provided to verify it.

[0070] Table 2

[0071]

[0072] In Embodiment 15, the average pore diameter D1 of the drainage hole section 111 is set as 3.6 mm, and the average pore diameter D2 of the injection hole section 112 is set as 3 mm. At this time, it can be known that the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 is 1.2. Through experimental verification, during liquid injection, no electrolyte was found to emerge around the liquid injection hole 11.

[0073] In Embodiment 16, the average pore diameter D1 of the drainage hole section 111 is set as 7.5 mm, and the average pore diameter D2 of the injection hole section 112 is set as 5 mm. At this time, it can be known that the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 is 1.5. Through experimental verification, during liquid injection, no electrolyte was found to emerge around the liquid injection hole 11.

[0074] In Embodiment 17, the average pore diameter D1 of the drainage hole section 111 is set as 4.53 mm, and the average pore diameter D2 of the injection hole section 112 is set as 3 mm. At this time, it can be known that the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 is 1.51. Through experimental verification, during liquid injection, no electrolyte was found to emerge around the liquid injection hole 11.

[0075] In Example 18, the average pore diameter D1 of the drainage hole section 111 is set to 5.46 mm, and the average pore diameter D2 of the injection hole section 112 is set to 3 mm. At this time, it can be known that the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 is 1.82. After experimental verification, no electrolyte was found to ooze out around the injection hole 11 during liquid injection.

[0076] In Example 19, the average pore diameter D1 of the drainage hole section 111 is set to 6.03 mm, and the average pore diameter D2 of the injection hole section 112 is set to 3 mm. At this time, it can be known that the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 is 2.01. After experimental verification, no electrolyte was found to ooze out around the injection hole 11 during liquid injection.

[0077] In Example 20, the average pore diameter D1 of the drainage hole section 111 is set to 6.63 mm, and the average pore diameter D2 of the injection hole section 112 is set to 3 mm. At this time, it can be known that the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 is 2.21. After experimental verification, no electrolyte was found to ooze out around the injection hole 11 during liquid injection.

[0078] In Example 21, the average pore diameter D1 of the drainage hole section 111 is set to 7.17 mm, and the average pore diameter D2 of the injection hole section 112 is set to 3 mm. At this time, it can be known that the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 is 2.39. After experimental verification, no electrolyte was found to ooze out around the injection hole 11 during liquid injection.

[0079] In Example 22, the average pore diameter D1 of the drainage hole section 111 is set to 5 mm, and the average pore diameter D2 of the injection hole section 112 is set to 2 mm. At this time, it can be known that the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 is 2.5. After experimental verification, no electrolyte was found to ooze out around the injection hole 11 during liquid injection.

[0080] In Example 23, the average pore diameter D1 of the drainage hole section 111 is set to 7.95 mm, and the average pore diameter D2 of the injection hole section 112 is set to 3 mm. At this time, it can be known that the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 is 2.65. After experimental verification, no electrolyte was found to ooze out around the injection hole 11 during liquid injection.

[0081] In Example 24, the average pore diameter D1 of the drainage hole section 111 is set to 9 mm, and the average pore diameter D2 of the injection hole section 112 is set to 3 mm. At this time, it can be known that the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 is 3. Through experimental verification, no electrolyte was found to emerge around the injection hole 11 during liquid injection.

[0082] It can be seen from Examples 15 to 24 that when the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 satisfies the range of 1.2 ≤ D1 / D2 ≤ 3, the size of the buffer step surface 113 formed between the drainage hole section 111 and the injection hole section 112 is moderate. It can not only ensure the structural strength at the location where the injection hole 11 is opened, but also avoid the size of the buffer step surface 113 being too large and affecting the liquid injection speed.

[0083] In Comparative Example 6, the average pore diameter D1 of the drainage hole section 111 is set to 3 mm, and the average pore diameter D2 of the injection hole section 112 is set to 3 mm. At this time, it can be known that the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 is 1. Through experimental verification, no electrolyte was found to emerge around the injection hole 11 during liquid injection, but the electrode group was damaged. However, since the injection hole 11 is a straight through hole, the structural strength at the injection hole 11 is weak, and deformation occurs after assembly.

[0084] It can be seen from Comparative Example 6 that when the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 is less than the minimum value of the range of 1.2 ≤ D1 / D2 ≤ 3, especially in Comparative Example 6, at this time the injection hole 11 is a straight through hole, resulting in the absence of the buffer step surface 113 at the injection hole 11. Therefore, during liquid injection, the electrode group is slightly damaged.

[0085] In Comparative Example 7, the average pore diameter D1 of the drainage hole section 111 is set to 15 mm, and the average pore diameter D2 of the injection hole section 112 is set to 3 mm. At this time, it can be known that the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 is 5. Through experimental verification, electrolyte was found to emerge around the injection hole 11 during liquid injection.

[0086] It can be seen from Comparative Example 7 that when the ratio between the average pore diameter D1 of the drainage hole section 111 and the average pore diameter D2 of the injection hole section 112 is greater than the maximum value of the range of 1.2 ≤ D1 / D2 ≤ 3, at this time, since the size of the buffer step surface 113 formed between the drainage hole section 111 and the injection hole section 112 is too large, a large amount of electrolyte will be blocked by the buffer step surface 113 when passing through the drainage hole section 111, thereby reducing the flow rate flowing into the injection hole section 112, resulting in electrolyte overflow and emerging from the injection hole 11.

[0087] Optionally, as Figure 2 shown, the drainage hole section 111 is in a horn shape with an inner diameter gradually decreasing towards the injection hole section 112. By making the drainage hole section 111 in a horn shape with an inner diameter gradually decreasing towards the injection hole section 112, it is convenient to converge the electrolyte so that the electrolyte flows into the injection hole section 112. In this embodiment, the aperture D1 of the drainage hole section 111 is the minimum aperture value of the drainage hole section 111.

[0088] Optionally, as Figure 2 shown, a plugging boss 12 inserted into the liquid injection groove 23 is further provided on one side of the cover plate body 1 facing the insulating structural member 2, and the injection hole section 112 is opened on the plugging boss 12. By providing the plugging boss 12 on one side of the cover plate body 1 facing the insulating structural member 2 and inserting the plugging boss 12 into the liquid injection groove 23, the flow path of the electrolyte is extended by using the plugging boss 12, so that the electrolyte directly falls into the liquid injection groove 23 after flowing out, avoiding the problem that the electrolyte flows into the gap between the cover plate body 1 and the insulating structural member 2, resulting in leakage and causing insulation failure.

[0089] Among them, the shape of the plugging boss 12 can be freely set according to requirements, and can be a circular boss or a rectangular boss, etc. In this embodiment, the shape of the plugging boss 12 matches the shape of the liquid injection groove 23 and is a circular boss.

[0090] Optionally, as Figure 2 shown, the thickness dimension of the cover plate body 1 is H, and the distance between the buffer step surface 113 and the surface of the plugging boss 12 facing the insulating structural member 2 is H1, and 0.6mm ≤ H1 ≤ H is satisfied. By setting the distance between the buffer step surface 113 and the surface of the plugging boss 12 facing the insulating structural member 2 as H1 and limiting the distance H1 between the buffer step surface 113 and the surface of the plugging boss 12 facing the insulating structural member 2 to satisfy 0.6mm ≤ H1 ≤ H, it is avoided that the drainage hole section 111 with a relatively large aperture size is too large, resulting in a reduction in the structural strength of the cover plate body 1. In this embodiment, when the values of H1 and H are equal, the liquid injection hole 11 is only composed of the injection hole section 112 at this time.

[0091] Optionally, the 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 insulating structural member 2, on the one hand, the insulation of the insulating structural member 2 is ensured, and on the other hand, it is convenient to form the required liquid injection groove 23 and the first liquid injection channel 233 and the second liquid injection channel 234 in the liquid injection groove 23 during production.

[0092] In this embodiment, a battery is further provided. The battery includes a pole group and the above-mentioned battery housing, and the pole group is accommodated in the battery housing. By applying the above-mentioned battery housing, the risk of insulation failure is effectively reduced, the yield of the product is improved, and the manufacturing cost is reduced.

[0093] Obviously, the above 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. A battery housing, characterized in that: The battery housing comprises a cover plate body, a housing body and an insulating structural member, wherein the housing body is a hollow shell structure with an opening, the cover plate body is arranged at the opening of the housing body to form a receiving cavity for receiving the electrode group, a liquid injection hole is provided on a wall surface of the cover plate body or the housing body opposite to the electrode ear of the electrode group, and the insulating structural member is located in the receiving cavity and is arranged on a side of the electrode group extending from the electrode ear; The insulating structure comprises a first surface, a second surface and a liquid injection groove, wherein the liquid injection groove is recessed from the first surface to the second surface and protrudes from the second surface, the liquid injection hole is located within the projection of the liquid injection groove along the first direction, the liquid injection groove comprises a first wall surface and a second wall surface, a first liquid injection channel is provided on the first wall surface, and a second liquid injection channel is provided on the second wall surface; The effective cross-sectional area of ​​the first injection channel is S1, the effective cross-sectional area of ​​the second injection channel is S2, the effective cross-sectional area of ​​the injection hole is S, the effective cross-sectional area S1 of the first injection channel is smaller than the effective cross-sectional area S of the injection hole, and satisfies 1≤(S1+S2) / S≤1.

5.

2. The battery housing according to claim 1, characterized in that: The thickness dimension of the first wall surface is t1, and satisfies 0.5 mm ≤ t1 ≤ 3 mm.

3. The battery housing according to claim 1, characterized in that: The thickness dimension of the second wall surface is t2, and satisfies 0.5 mm ≤ t2 ≤ 3 mm.

4. The battery housing according to claim 1, characterized in that: The injection hole includes a drainage hole section and an injection hole section, the drainage hole section is located on the side of the cover plate body away from the insulating structural component, and the injection hole section is located on the side of the cover plate body facing the insulating structural component, the aperture of the drainage hole section is larger than the aperture of the injection hole section, and a buffer step surface is formed between the drainage hole section and the injection hole section, and the effective cross-sectional area of ​​the injection hole section is used to constitute the effective cross-sectional area S of the injection hole.

5. The battery housing according to claim 4, characterized in that: The average pore size of the drainage hole section is D1, the average pore size of the injection hole section is D2, and they satisfy 1.2≤D1 / D2≤3, and the effective cross-sectional area of ​​the injection hole is S=(D2 / 2) 2 ·π.

6. The battery housing according to claim 4, characterized in that: The drainage hole section is in a trumpet shape with an inner diameter gradually decreasing as it approaches the injection hole section.

7. The battery housing according to claim 4, characterized in that: A plug-in boss plugged into the injection groove is further provided on one side of the cover body facing the insulating structure, and the injection hole section is arranged on the plug-in boss.

8. The battery casing according to claim 7, characterized in that: The thickness dimension of the cover plate body is H, the distance between the buffer step surface and the surface of the plug-in boss facing the insulating structural member is H1, and 0.6 mm≤H1≤H is satisfied.

9. The battery housing according to claim 1, characterized in that: The insulating structural component is a plastic component integrally formed by an injection molding process.

10. A battery, characterized in that The battery comprises a pole group and a battery casing as claimed in any one of claims 1 to 9, wherein the pole group is accommodated in the battery casing.

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