Battery cell shell and battery cell
By installing reinforcement on the battery cell shell, the welding deformation problem is solved, the production yield and structural strength are improved, and more efficient heat loss is achieved.
Patent Information
- Application Number
- CN202510303079.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2025-06-13
AI Technical Summary
When the existing battery cells are equipped with explosion-proof valves, the welding deformation problem is serious, resulting in a decrease in production yield, an increase in production cost, and high welding process requirements.
Design a battery cell housing, including the shell body, an explosion-proof valve and two reinforcements. The explosion-proof valve is welded on the first side wall of the shell body, and the two reinforcements are clamped at the reinforcement grooves respectively, and the tensile strength and heat dissipation coefficient of the material are higher than that of the shell body.
By setting up reinforcements, the local structural strength of the shell is improved, the welding deformation problem is alleviated, the production yield is improved, and the heat loss is promoted, and the impact of welding heat on the shell is reduced.
Smart Images
Figure CN120149652A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of energy storage devices, and particularly to a cell housing and a cell. Background Art
[0002] To ensure the safety of cell use, an explosion-proof valve is generally provided on the cell top cover. However, since the cell top cover is located at one end of the cell in the length direction, the path for gas to reach the explosion-proof valve is relatively long, which is not conducive to the safety of the cell. If the explosion-proof valve is provided on the cell housing, the exhaust path can be shortened, thereby improving the safety of the cell. However, compared with the top cover, the wall thickness of the housing is thinner, and in order to arrange the explosion-proof valve, an opening needs to be made on the housing, which will further result in a weaker housing structure at the welding position of the explosion-proof valve. Welding is likely to cause deformation of the housing, affecting the subsequent assembly and use of the cell. Moreover, the heat generated by welding the explosion-proof valve to the housing cannot be dissipated quickly, which will further aggravate the degree of housing deformation. Therefore, the requirements for the welding process will increase, the production yield will decrease, the production cost will increase, and the production efficiency will decrease. Summary of the Invention
[0003] An object of the present invention is to provide a cell housing which can improve the safety of the cell while helping to alleviate the problem of welding deformation and improving the production yield.
[0004] To achieve this purpose, the present invention adopts the following technical solutions:
[0005] Provide a cell housing, comprising:
[0006] A housing body, one end of the housing body in its own width direction has a first side wall, and an explosion-proof through hole and two strengthening grooves are provided on the first side wall;
[0007] An explosion-proof valve, which is welded at the explosion-proof through hole;
[0008] Two strengthening members, the two strengthening members are respectively clamped at the two strengthening grooves, along the thickness direction of the housing body, one strengthening member, the explosion-proof valve and the other strengthening member are arranged in sequence, the tensile strength of the material of the strengthening member is greater than the tensile strength of the material of the housing body, and the heat dissipation coefficient of the material of the strengthening member is greater than the heat dissipation coefficient of the material of the housing body.
[0009] Optionally, the strengthening member protrudes from the outer wall surface of the first side wall.
[0010] Optionally, the height W of the strengthening member protruding from the outer wall surface of the first side wall satisfies W≥0.3 mm;
[0011] And / or, the dimension F of the part of the strengthening member protruding from the outer wall surface of the first side wall along the thickness direction of the housing body satisfies F≥0.8 mm;
[0012] And / or, the height W of the reinforcing member protruding from the outer wall surface of the first side wall and the dimension F of the portion of the reinforcing member protruding from the outer wall surface of the first side wall in the thickness direction of the housing body satisfy 0.24 mm 2 ≤W×F≤0.5 mm 2 .
[0013] Optionally, in the thickness direction of the housing body, the projection area of the explosion-proof valve falls within the projection area of the reinforcing member.
[0014] Optionally, in the length direction of the housing body, the dimension L1 of the reinforcing member and the dimension L2 of the explosion-proof valve satisfy 1.2 ≤ L1 / L2 ≤ 1.6.
[0015] Optionally, the first side wall is provided with a limiting groove, the limiting groove and the two reinforcing grooves are opened on the same side of the first side wall, the explosion-proof through hole is opened at the bottom of the limiting groove, the explosion-proof valve is located in the limiting groove, and in the thickness direction of the housing body, the shortest distance H between the notch of the limiting groove and the notch of any one of the reinforcing grooves satisfies H ≥ 1.5 mm.
[0016] Optionally, at least one of the reinforcing grooves is continuously opened on the outer wall surface of the first side wall in the length direction of the housing body.
[0017] Optionally, for any group of the reinforcing member and the reinforcing groove, in the thickness direction of the housing body, the dimension of the portion of the reinforcing member located in the reinforcing groove is greater than the dimension at the notch of the reinforcing groove.
[0018] Optionally, in the length direction of the housing body, the explosion-proof valve is located in the middle of the first side wall;
[0019] And / or, in the thickness direction of the housing body, the explosion-proof valve is located in the middle of the first side wall.
[0020] Another object of the present invention is to provide an electric core, which can improve the safety of the electric core, help to alleviate the problem of welding deformation, and improve the manufacturing yield.
[0021] To achieve this purpose, the present invention adopts the following technical solutions:
[0022] Provide an electric core, including a pole group and the above-mentioned electric core housing, and the pole group is located in the electric core housing.
[0023] The beneficial effects of the present invention:
[0024] The present invention provides an electric cell housing, which includes a housing body, an explosion-proof valve, and two reinforcing members. One end of the housing body in its own width direction has a first side wall, and an explosion-proof through hole and two reinforcing grooves are formed in the first side wall. The explosion-proof valve is welded at the explosion-proof through hole, and the two reinforcing members are respectively clamped at the two reinforcing grooves. Along the thickness direction of the housing body, one reinforcing member, the explosion-proof valve, and the other reinforcing member are arranged in sequence. The tensile strength of the material of the reinforcing member is greater than that of the material of the housing body, and the heat dissipation coefficient of the material of the reinforcing member is greater than that of the material of the housing body. By arranging the explosion-proof valve on the first side wall instead of the top cover of the electric cell, the exhaust path can be shortened, and the safety of the electric cell can be improved. The structural strength of the first side walls on both sides of the explosion-proof valve along the thickness direction of the housing body is the weakest, and it is most likely to deform during the welding process of the explosion-proof valve. The two reinforcing members are respectively arranged on both sides of the explosion-proof valve along the thickness direction of the housing body, so as to strengthen the weakest area and improve the local structural strength, achieving the effect of preventing deformation. Moreover, the reinforcing member can also accelerate the heat dissipation at the position where it is located, preventing the welding heat from further aggravating the deformation of the first side wall. Therefore, the electric cell housing can improve the safety of the electric cell while helping to alleviate the welding deformation problem of the housing body and improving the production yield.
[0025] The present invention also provides an electric cell, which includes a pole group and the above-mentioned electric cell housing, and the pole group is located inside the electric cell housing. This electric cell can improve the safety of the electric cell while helping to alleviate the welding deformation problem of the housing body and improving the production yield. Description of the Drawings
[0026] Figure 1 is a schematic structural diagram of the electric cell housing provided by an embodiment of the present invention from a first perspective;
[0027] Figure 2 is Figure 1 an enlarged view of part A in
[0028] Figure 3 is a schematic structural diagram of the electric cell housing provided by an embodiment of the present invention from a second perspective;
[0029] Figure 4 is Figure 3 a sectional view taken along line B-B in
[0030] Figure 5 is Figure 4 an enlarged view of part C in
[0031] Figure 6 is a sectional view of the reinforcing member.
[0032] In the figure:
[0033] 1. Housing body; 11. First side wall; 111. Reinforcing groove; 112. Limiting groove;
[0034] 2. Explosion-proof valve; 3. Reinforcement member. Detailed implementation manners
[0035] Before explaining any implementation manner of the present application in detail, it should be understood that the present application is not limited to the structural details and component arrangements set forth in the following description or shown in the above drawings.
[0036] In the present application, the terms "comprise", "include", "have" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.
[0037] In the present application, the term "and / or" describes the associative relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the present application, the character " / " generally represents an "and / or" relationship between the associated objects before and after.
[0038] In the present application, the terms "connect", "combine", "couple", "mount" can be direct connection, combination, coupling or mounting, or indirect connection, combination, coupling or mounting. Among them, by way of example, direct connection means that two parts or components are connected together without setting an intermediate member, and indirect connection means that two parts or components are respectively connected to at least one intermediate member, and these two parts or components are connected through the intermediate member. In addition, "connect" and "couple" are not limited to physical or mechanical connection or coupling, and can include electrical connection or coupling.
[0039] In the present application, those of ordinary skill in the art will understand that relative terms used in combination with quantities or conditions (such as "about", "approximately", "substantially", etc.) are intended to include the stated value and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances caused by manufacturing, assembly, use in relation to a particular value, etc. Such terms should also be considered to disclose a range defined by the absolute values of two endpoints. The relative terms may refer to a plus or minus a certain percentage (such as 1%, 5%, 10% or more) of the indicated value. A numerical value without using a relative term should also be disclosed as a particular value with a tolerance. In addition, when expressing a relative angular positional relationship (such as substantially parallel, substantially perpendicular), "substantially" may refer to a plus or minus a certain number of degrees (such as 1 degree, 5 degrees, 10 degrees or more) based on the indicated angle.
[0040] In the present application, those of ordinary skill in the art will understand that the functions performed by components can be performed by one component, multiple components, one part, or multiple parts. Similarly, the functions performed by parts can also be performed by one part, one component, or a combination of multiple parts.
[0041] In the present application, the orientation terms such as "upper", "lower", "left", "right", "front", and "rear" are described based on the orientation and positional relationship shown in the drawings, and should not be construed as a limitation on the embodiments of the present application. In addition, in the context, it should also be understood that when it is mentioned that one element is connected "above" or "below" another element, it can not only be directly connected "above" or "below" another element, but also be indirectly connected "above" or "below" another element through an intermediate element. It should also be understood that the orientation terms such as the upper side, lower side, left side, right side, front side, and rear side not only represent the positive orientation, but can also be understood as the side orientation. For example, the lower side can include directly below, lower left, lower right, lower front, and lower rear, etc.
[0042] To ensure the safety of the use of the battery cell, an explosion-proof valve is generally provided on the top cover of the battery cell. However, since the top cover of the battery cell is located at one end of the length direction of the battery cell, the path for the gas to reach the explosion-proof valve is relatively long, which is not conducive to the safety of the battery cell. If the explosion-proof valve is provided on the battery cell housing, the exhaust path can be shortened, and the safety of the battery cell can be improved. However, compared with the top cover, the wall thickness of the housing is thinner, and in order to arrange the explosion-proof valve, holes need to be opened on the housing, which will further cause the structure of the housing at the welding place of the explosion-proof valve to be weak, and the welding is likely to cause deformation of the housing, affecting the subsequent assembly and use of the battery cell. Moreover, the heat generated by welding the explosion-proof valve on the housing cannot be quickly dissipated, which will further aggravate the degree of deformation of the housing. Therefore, the requirements for the welding process will increase, the production yield will decrease, the production cost will increase, and the production efficiency will decrease.
[0043] Therefore, the present embodiment provides a battery cell housing to solve the above problems. The battery cell housing can improve the safety of the battery cell while helping to alleviate the welding deformation problem of the housing body and improve the production yield.
[0044] As Figures 1-6 shown, the battery cell housing of the present embodiment includes a housing body 1, an explosion-proof valve 2, and two reinforcing members 3. Figure 1 In the ab direction in, the ab direction is the length direction of the housing body 1, the cd direction is the width direction of the housing body 1, the ef direction is the thickness direction of the housing body 1, and the ab direction, the cd direction, and the ef direction are perpendicular to each other in pairs.
[0045] One end of the shell body 1 in its own width direction has a first side wall 11, and an explosion-proof through hole and two reinforcing grooves 111 are formed in the first side wall 11. The explosion-proof valve 2 is welded at the explosion-proof through hole, and two reinforcing members 3 are respectively clamped at the two reinforcing grooves 111. Along the thickness direction of the shell body 1, one reinforcing member 3, the explosion-proof valve 2, and the other reinforcing member 3 are arranged in sequence. The tensile strength of the material of the reinforcing member 3 is greater than that of the material of the shell body 1, and the heat dissipation coefficient of the material of the reinforcing member 3 is greater than that of the material of the shell body 1.
[0046] By arranging the explosion-proof valve 2 on the first side wall 11 instead of the top cover of the battery cell, the exhaust path can be shortened, and the safety of the battery cell can be improved. The structural strength of the first side wall 11 on both sides of the explosion-proof through hole is the weakest, and it is most likely to deform during the welding process of the explosion-proof valve 2, and even affect the deformation of the side surface of the adjacent shell body 1. The two reinforcing members 3 are respectively arranged on both sides of the explosion-proof valve 2 along the thickness direction of the shell body 1, so that the weakest area can be strengthened, the local structural strength can be improved, and the deformation can be prevented. Moreover, the reinforcing member 3 can also accelerate the heat dissipation at the position where it is located, and prevent the welding heat from further aggravating the deformation of the first side wall 11. Therefore, the battery cell shell can improve the safety of the battery cell while helping to relieve the welding deformation problem of the shell body 1 and improve the manufacturing yield.
[0047] Optionally, at least one reinforcing groove 111 is formed through the outer wall surface of the first side wall 11 along the length direction of the shell body 1. The reinforcing groove 111 itself has the function of absorbing deformation, can block the deformation area, and prevent the side surface with the largest area of the shell body 1 from deforming. The reinforcing groove 111 is formed through along the length direction of the shell body 1, so that the deformation acting forces at all positions along the length direction of the shell body 1 can be absorbed by the reinforcing groove 111, and the side surface with the largest area can be avoided from deforming as a whole. Optionally, in this embodiment, both ends of the two reinforcing grooves 111 are formed through.
[0048] Optionally, the length direction of the reinforcing member 3 is parallel to the length direction of the shell body 1. Optionally, the reinforcing member 3 protrudes from the outer wall surface of the first side wall 11, that is, the reinforcing groove 111 is formed in the outer wall surface of the first side wall 11, and the reinforcing member 3 protrudes from the edge of the groove, which can further improve the anti-bending ability of the reinforcing member 3 and can further increase the heat dissipation area and the heat dissipation efficiency.
[0049] Optionally, the end of the reinforcing member 3 outside the reinforcing groove 111 is higher than the outer end surface of the explosion-proof valve 2. The protruding arrangement of the reinforcing member 3 can also protect the explosion-proof valve 2 to a certain extent, especially protecting the explosion-proof valve 2 from being knocked during the manufacturing process of the battery cell.
[0050] Optionally, the height W of the reinforcing member 3 protruding from the outer wall surface of the first side wall 11 satisfies W≥0.3 mm. If the height W of the reinforcing member 3 protruding from the outer wall surface of the first side wall 11 is less than 0.3 mm, the heat dissipation area is too small, and the heat dissipation effect is average. The welding heat cannot be quickly dissipated into the environment, and the first side wall 11 still has the possibility of deformation.
[0051] Optionally, the dimension F of the portion of the reinforcing member 3 protruding from the outer wall surface of the first side wall 11 in the thickness direction of the housing body 1 satisfies F≥0.8 mm. When the dimension F of the portion of the reinforcing member 3 protruding from the outer wall surface of the first side wall 11 in the thickness direction of the housing body 1 is less than 0.8 mm, that is, when the thickness of the reinforcing member 3 itself is small, its own anti-bending performance is low, and the effect of strengthening the first side wall 11 is average.
[0052] Optionally, the height W of the reinforcing member 3 protruding from the outer wall surface of the first side wall 11 and the dimension F of the portion of the reinforcing member 3 protruding from the outer wall surface of the first side wall 11 in the thickness direction of the housing body 1 satisfy 0.24 mm 2 ≤W×F≤0.5 mm 2 . The product of the two is greater than or equal to 0.24 mm 2 It can ensure that the reinforcing member 3 has strong self-structural strength and good heat dissipation performance. However, when the product of the two is greater than 0.5 mm 2 , on the one hand, the cost of the reinforcing member 3 is too high. On the other hand, if the height W of the reinforcing member 3 protruding from the outer wall surface of the first side wall 11 is too large, it will occupy too much space outside the battery core, which is likely to affect the layout of the battery module. If the dimension F of the portion of the reinforcing member 3 protruding from the outer wall surface of the first side wall 11 in the thickness direction of the housing body 1 is too large, the reinforcing groove 111 is too wide, which is not conducive to the structural strength of the first side wall 11 itself, and the reinforcing member 3 is easily too close to the explosion-proof valve 2, interfering with the welding process of the explosion-proof valve 2.
[0053] As Figure 1 and Figure 5 shown, optionally, in the thickness direction of the housing body 1, the projection area of the explosion-proof valve 2 falls within the projection area of the reinforcing member 3 to ensure that the areas greatly affected by welding are all provided with the reinforcing member 3 for structural strengthening and timely heat dissipation.
[0054] As Figure 3As shown, optionally, along the length direction of the shell body 1, the dimension L1 of the reinforcing member 3 and the dimension L2 of the explosion-proof valve 2 satisfy 1.2 ≤ L1 / L2 ≤ 1.6. The length of the reinforcing member 3 is further extended based on the length of the explosion-proof valve 2, which can protect the vulnerable areas around the explosion-proof valve 2. Once the ratio of the dimension L1 of the reinforcing member 3 to the dimension L2 of the explosion-proof valve 2 is less than 1.2, or the common plane where the midlines of the reinforcing member 3 and the explosion-proof valve 2 are located in their respective length directions is perpendicular to the length direction of the shell body 1, there will be a greater risk of deformation at the first side wall 11 at both ends of the reinforcing member 3 along its own length direction, and the heat in this area is not easily dissipated, which will further increase the risk of deformation.
[0055] As Figure 5 shown, optionally, a limiting groove 112 is formed on the first side wall 11. The limiting groove 112 and the two reinforcing grooves 111 are formed on the same side of the first side wall 11. Optionally, in this embodiment, the limiting groove 112 and the two reinforcing grooves 111 are both formed on the outer wall surface of the first side wall 11. The explosion-proof through hole is formed at the bottom of the limiting groove 112, and the explosion-proof valve 2 is located in the limiting groove 112. However, since both the limiting groove 112 and the reinforcing groove 111 are relatively thin, in order to prevent the structural strength of the first side wall 11 itself from being too low, therefore, along the thickness direction of the shell body 1, the shortest distance H between the notch of the limiting groove 112 and the notch of any one of the reinforcing grooves 111 satisfies H ≥ 1.5 mm. The above design can not only ensure the structural strength of the area between the limiting groove 112 and the reinforcing groove 111, but also facilitate the welding operation. The fusion width of laser welding is generally about 0.8 mm - 1.5 mm. H ≥ 1.5 mm can prevent interference with welding or being unfavorable for welding operation due to the too close distance between the limiting groove 112 and the reinforcing groove 111, thereby reducing the difficulty of the welding process and improving the yield.
[0056] Optionally, for any group of the reinforcing member 3 and the reinforcing groove 111, along the thickness direction of the shell body 1, the dimension of the part of the reinforcing member 3 located in the reinforcing groove 111 is larger than the dimension at the notch of the reinforcing groove 111, so as to facilitate the clamping of the reinforcing member 3 at the reinforcing groove 111. Optionally, in this embodiment, the part of the reinforcing member 3 located inside the reinforcing groove 111 protrudes outwards along its own thickness direction, and the reinforcing groove 111 is formed in a shape following the reinforcing member 3. The reinforcing member 3 can be inserted into the reinforcing groove 111 from the through hole at one end of the reinforcing groove 111.
[0057] Optionally, along the length direction of the shell body 1, the explosion-proof valve 2 is located in the middle of the first side wall 11. Optionally, along the thickness direction of the shell body 1, the explosion-proof valve 2 is located in the middle of the first side wall 11, preventing excessive influence on the adjacent surface on one side due to deviation from the middle.
[0058] Optionally, the midline of the explosion-proof valve 2 is in the first plane, and the midline of at least one reinforcing member 3 is in the second plane. Both the first plane and the second plane are perpendicular to the length direction of the housing body 1, and the first plane and the second plane coincide. Optionally, in this embodiment, the two reinforcing members 3 have the same length, are aligned, and the midline of the explosion-proof valve 2 and the midlines of the two reinforcing members 3 are all in one plane.
[0059] Optionally, the material of the reinforcing member 3 is copper or alloy with a higher stiffness and heat dissipation coefficient than aluminum, and the material of the housing body 1 is aluminum.
[0060] Experimental tests were carried out on the battery cell housings of different sizes. The test contents included measuring the deformation size of the housing body 1 after welding the explosion-proof valve 2 to the battery cell housing, performing helium leak detection on the housing body 1, and additionally calculating the cost of the reinforcing member 3.
[0061] Table 1
[0062]
[0063] Table 1 lists six examples and five comparative examples. Some of the dimensions of the examples and the comparative examples are the same, such as L1, L2, T, H, and F. Among them, T is the thickness of the first side wall 11 where there are no openings or grooves. And the ratios of L1 and L2 all meet the more optimal value range in the above design, that is, 1.2 - 1.6, the value of H is also greater than 1.5 mm, and the value of F is also 0.8 mm. The difference between the examples and the comparative examples lies in the values of W and W×F.
[0064] The height W of the reinforcing member 3 protruding from the outer wall surface of the first side wall 11 of the battery cell housings of Examples 1 to 6 is in the range of 0.3 mm - 0.6 mm, all meeting the more optimal value range of W≥0.3 mm. After welding the explosion-proof valve 2 to the battery cell housings of these six examples, no out-of-tolerance deformation occurred on the larger side surfaces, that is, no concave or convex deformation with a depth greater than 0.4 mm. And the process of welding the explosion-proof valve 2 to the battery cell housings of these six examples also all met the technical requirements, and the helium leak detection results of the battery cell housings after welding also all met the requirements, proving that the structural strength, airtightness, etc. of the battery cell housings all met the requirements, and the yield rate could reach 100%. The above experimental results prove that the setting of the reinforcing member 3 can completely solve the problem of deformation caused by welding the explosion-proof valve 2 to the housing body 1, thereby ensuring the subsequent smooth assembly of the electrode group of the battery cell. Therefore, while the explosion-proof valve 2 can be welded to the side of the battery cell housing to improve the safety of the battery cell, it can ensure that the structural strength, airtightness, etc. of the battery cell all meet the requirements, and overall improve the quality of the battery cell.
[0065] The reinforcing member 3 of the battery cell housing of Comparative Example 1 is flush with the outer wall surface of the first side wall 11. After welding the explosion-proof valve 2, the housing body 1 shows obvious out-of-tolerance deformation on the side with the largest area, that is, concave or convex deformation with a depth greater than 0.4 mm. The process of welding the explosion-proof valve 2 to the housing body 1 meets the technical requirements, and the helium leak detection result of the battery cell housing after welding also meets the requirements, but the yield of this battery cell housing is less than 98%. It can be seen that setting the reinforcing member 3 can indeed alleviate the deformation problem to a certain extent, ensure that the welding process of the battery cell housing meets the technical requirements, and the airtightness of the battery cell housing after welding is good. However, when the height W of the reinforcing member 3 protruding from the outer wall surface of the first side wall 11 is less than 0.3 mm, its anti-deformation ability and heat conduction ability are still insufficient. After welding the explosion-proof valve 2 to the housing body 1, there is still out-of-tolerance deformation on the side with the largest area of the housing body 1.
[0066] For the battery cell housing of Comparative Example 2, the value of W is 0.15 mm. After welding the explosion-proof valve 2, obvious out-of-tolerance deformation still appears on the side with the largest area of the housing body 1. The process of welding the explosion-proof valve 2 to the housing body 1 meets the technical requirements, and the helium leak detection result of the battery cell housing after welding also meets the requirements, but the yield of this battery cell housing is less than 98%.
[0067] For the battery cell housing of Comparative Example 3, the value of W is 0.2 mm. After welding the explosion-proof valve 2, obvious out-of-tolerance deformation still appears on the side with the largest area of the housing body 1. However, compared with Comparative Example 1 and Comparative Example 2, the deformation depth of Comparative Example 3 decreases. The process of welding the explosion-proof valve 2 to the housing body 1 meets the technical requirements, and the helium leak detection result of the battery cell housing after welding also meets the requirements, but the yield of this battery cell housing is still less than 98%, but its yield is already higher than that of Comparative Example 1 and Comparative Example 2. It can be seen that as the height W of the reinforcing member 3 protruding from the outer wall surface of the first side wall 11 gradually approaches the more optimal value range, the manufacturing yield also increases accordingly.
[0068] For the battery cell housing of Comparative Example 4, the value of W is 0.25 mm. After welding the explosion-proof valve 2, only slight deformation appears on the side with the largest area of the housing body 1. The process of welding the explosion-proof valve 2 to the housing body 1 meets the technical requirements, and the helium leak detection result of the battery cell housing after welding also meets the requirements, but the yield of this battery cell housing is still less than 98%, but its yield is already higher than that of Comparative Example 3. It can be seen that as the height W of the reinforcing member 3 protruding from the outer wall surface of the first side wall 11 further approaches the more optimal value range, no out-of-tolerance deformation appears on the side with the largest area of the housing body 1 after welding the explosion-proof valve 2, and only slight deformation exists, and the severity of the deformation problem is greatly reduced.
[0069] For Comparative Example 5, the value of W for the cell case is 0.7 mm, and the shell body 1 has no deformation after welding the explosion-proof valve 2. The process of welding the explosion-proof valve 2 to the shell body 1 meets the technical requirements, and the helium leak detection result of the cell case after welding also meets the requirements. The yield rate of the cell case also reaches 100%. However, since the material of the reinforcing member 3 is copper, its cost increases significantly.
[0070] Table 2
[0071]
[0072] Table 2 lists five examples and four comparative examples. Some dimensions of the examples and comparative examples are the same, such as L2, T, W, and F. Among them, T is the thickness of the first side wall 11 where no holes or slots are opened. Moreover, the values of W, F, and W×F all fall within the more optimal value range in the above design. The differences between the examples and the comparative examples lie in the values of L1, H, and L1 / L2.
[0073] For the cell cases of Examples 7 to 11, the value range of the length L1 of the reinforcing member 3 is 79 mm - 100 mm, and the value range of L1 / L2 is 1.2 - 1.52, both of which fall within the more optimal value range of 1.2 ≤ L1 / L2 ≤ 1.6. After welding the explosion-proof valve 2 to the cell cases of these five examples, no out-of-tolerance deformation occurs on the larger-area sides, and the process of welding the explosion-proof valve 2 meets the technical requirements. The helium leak detection results of the cell cases after welding also meet the requirements, proving that the structural strength, airtightness, etc. of the cell cases all meet the requirements, and the yield rate can reach 100%. The above experimental results prove that when the values of L1, H, and L1 / L2 all fall within the above more optimal value range, the setting of the reinforcing member 3 can completely solve the problem of deformation caused by welding the explosion-proof valve 2 to the shell body 1, thus ensuring the subsequent smooth assembly of the electrode group for the cell. Therefore, while the explosion-proof valve 2 can be welded to the side of the cell case to improve the safety of the cell, the structural strength and airtightness of the cell can be ensured to meet the requirements, and the quality of the cell can be improved as a whole.
[0074] For Comparative Example 6, the length of the reinforcing member 3 of the cell case is smaller than the length of the explosion-proof valve 2. After welding the explosion-proof valve 2 to the shell body 1, obvious out-of-tolerance deformation occurs on the side with the largest area. The process of welding the explosion-proof valve 2 to the shell body 1 meets the technical requirements, and the helium leak detection result of the cell case after welding also meets the requirements. However, the yield rate of this cell case is less than 98%. It can be seen that when the protruding height of the reinforcing member 3 meets the more optimal value range, if the length of the reinforcing member 3 is insufficient, its heat dissipation efficiency is insufficient, and the shell body 1 at both ends of the explosion-proof valve 2 still cannot be fully supported, resulting in insufficient structural strength, so that obvious out-of-tolerance deformation occurs on the side with the largest area of the shell body 1 after welding the explosion-proof valve 2.
[0075] The length of the reinforcing member 3 of the battery cell housing of Comparative Example 7 is the same as that of the explosion-proof valve 2, but obvious out-of-tolerance deformation still occurred on the side with the largest area of the housing body 1 after welding the explosion-proof valve 2. The process of welding the explosion-proof valve 2 to the housing body 1 meets the technical requirements, and the helium leak detection result of the battery cell housing after welding also meets the requirements, but the yield of the battery cell housing is less than 98%. It can be seen that the housing body 1 outside the two ends of the explosion-proof valve 2 is still affected by welding, and due to the lack of support and sufficient heat dissipation of the reinforcing member 3, obvious deformation still exists in the housing body 1 outside the two ends of the explosion-proof valve 2.
[0076] The length of the reinforcing member 3 of the battery cell housing of Comparative Example 8 is further increased, but L1 / L2 is 1.18, which is still smaller than 1.2. Slight out-of-tolerance deformation occurred on the side with the largest area of the housing body 1 after welding the explosion-proof valve 2. The process of welding the explosion-proof valve 2 to the housing body 1 meets the technical requirements, and the helium leak detection result of the battery cell housing after welding also meets the requirements, but the yield of the battery cell housing is still less than 98%. It can be seen that as the ratio of the length of the reinforcing member 3 to the length of the explosion-proof valve 2 gradually approaches the more optimal value range, only slight out-of-tolerance deformation exists on the side with the largest area of the housing body 1 after welding the explosion-proof valve 2, and the severity of the deformation is greatly reduced.
[0077] The length of the reinforcing member 3 of the battery cell housing of Comparative Example 9 is further increased, and L1 / L2 is 1.82, that is, greater than 1.6. No deformation occurred on the housing body 1 after welding the explosion-proof valve 2. The process of welding the explosion-proof valve 2 to the housing body 1 meets the technical requirements, and the helium leak detection result of the battery cell housing after welding also meets the requirements, and the yield is 100%. However, due to the excessive length of the reinforcing member 3, the cost of the reinforcing member 3 is too high.
[0078] It can be seen that arranging a reinforcing member 3 on each side of the explosion-proof valve 2 along the thickness direction of the housing body 1 can effectively alleviate the problem of deformation of the housing body 1 after welding the explosion-proof valve 2. Moreover, when the height W of the part of the reinforcing member 3 protruding from the outer wall surface of the first side wall 11, the dimension F of the part of the reinforcing member 3 protruding from the outer wall surface of the first side wall 11 along the thickness direction of the housing body 1, the ratio of the length L1 of the reinforcing member 3 to the length L2 of the explosion-proof valve 2, and the shortest distance H between the notch of the limiting groove 112 and the notch of any one of the reinforcing grooves 111 respectively meet the above more optimal value range, the problem of deformation of the housing body 1 after welding the explosion-proof valve 2 can be completely solved, ensuring that aspects such as the structural strength and airtightness of the battery cell meet the requirements, and overall improving the quality of the battery cell.
[0079] This embodiment also provides a battery cell, including a pole group and the above-mentioned battery cell housing, and the pole group is located inside the battery cell housing. This battery cell can improve the safety of the battery cell while the battery cell housing is not easily deformed, improving the manufacturing yield.
[0080] 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, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, improvements, etc. 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 cell housing, characterized in that: include: A shell body (1), wherein the shell body (1) has a first side wall (11) at one end along its width direction, and the first side wall (11) is provided with an explosion-proof through hole and two reinforcement grooves (111); An explosion-proof valve (2), the explosion-proof valve (2) being welded to the explosion-proof through hole; Two reinforcing members (3), the two reinforcing members (3) are respectively clamped at the two reinforcing grooves (111), and along the thickness direction of the shell body (1), one reinforcing member (3), the explosion-proof valve (2) and the other reinforcing member (3) are arranged in sequence, the tensile strength of the material of the reinforcing member (3) is greater than the tensile strength of the material of the shell body (1), and the heat dissipation coefficient of the material of the reinforcing member (3) is greater than the heat dissipation coefficient of the material of the shell body (1).
2. The battery cell casing according to claim 1, characterized in that: The reinforcement member (3) is arranged to protrude from the outer wall surface of the first side wall (11).
3. The battery cell casing according to claim 2, characterized in that: The height W of the reinforcement member (3) protruding from the outer wall surface of the first side wall (11) satisfies W≥0.3 mm; and / or, a dimension F of a portion of the reinforcement member (3) protruding from the outer wall surface of the first side wall (11) along the thickness direction of the shell body (1) satisfies the requirement that F ≥ 0.8 mm; and / or, the height W of the reinforcement member (3) protruding from the outer wall surface of the first side wall (11) and the dimension F of the portion of the reinforcement member (3) protruding from the outer wall surface of the first side wall (11) along the thickness direction of the shell body (1) satisfy: 0.24 mm 2 ≤W×F≤0.5mm 2 .
4. The battery cell casing according to claim 1, characterized in that: Along the thickness direction of the shell body (1), the projection area of the explosion-proof valve (2) falls within the projection area of the reinforcement (3).
5. The battery cell casing according to claim 4, characterized in that: Along the length direction of the shell body (1), the size L1 of the reinforcement member (3) and the size L2 of the explosion-proof valve (2) satisfy the following relationship: 1.2≤L1 / L2≤1.
6.
6. The battery cell casing according to any one of claims 1 to 5, characterized in that: The first side wall (11) is provided with a limiting groove (112), the limiting groove (112) and the two reinforcing grooves (111) are provided on the same side of the first side wall (11), the explosion-proof through hole is provided at the bottom of the limiting groove (112), the explosion-proof valve (2) is located in the limiting groove (112), and along the thickness direction of the shell body (1), the shortest distance H between the notch of the limiting groove (112) and the notch of any one of the reinforcing grooves (111) satisfies, H≥1.5mm.
7. The battery cell casing according to any one of claims 1 to 5, characterized in that: At least one of the reinforcement grooves (111) is formed on the outer wall surface of the first side wall (11) and extends through the shell body (1) in the length direction.
8. The battery cell casing according to any one of claims 1 to 5, characterized in that: For any set of the reinforcement member (3) and the reinforcement groove (111), along the thickness direction of the shell body (1), the size of the portion of the reinforcement member (3) located in the reinforcement groove (111) is larger than the size of the notch of the reinforcement groove (111).
9. The battery cell casing according to any one of claims 1 to 5, characterized in that: Along the length direction of the shell body (1), the explosion-proof valve (2) is located in the middle of the first side wall (11); And / or, along the thickness direction of the shell body (1), the explosion-proof valve (2) is located in the middle of the first side wall (11).
10. A battery cell, characterized in that: It comprises a pole group and a battery cell shell as claimed in any one of claims 1 to 9, wherein the pole group is located in the battery cell shell.