Battery cell explosion-proof shell and battery cell

Abstract

The invention relates to the technical field of energy storage equipment, in particular to a battery cell explosion-proof shell and a battery cell, and the battery cell explosion-proof shell comprises a shell body, an explosion-proof integrated piece and a fixing piece. Wherein the shell body is provided with a first side wall, and the first side wall is provided with an anti-explosion through hole and a first fixing through hole. The explosion-proof integrated piece covers the first side wall and comprises an explosion-proof part and a fixing part, the projection, facing the first side wall, of the explosion-proof part is located in the explosion-proof through hole, a second fixing through hole is formed in the fixing part, and the two ends, in the axial direction of the second fixing through hole, of the second fixing through hole are provided with a first opening and a second opening correspondingly; the area of the first opening is larger than that of the second opening, and the second opening faces the first side wall. The fixing piece is provided with a first part, a second part and a third part which are connected, the second fixing through hole is filled with the first part, the first fixing through hole is filled with the second part, and at least part of the third part abuts against the wall face, facing the inner cavity of the battery cell explosion-proof shell, of the first side wall. The battery cell comprises a battery cell top cover, a pole group and the battery cell explosion-proof shell.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage devices, and particularly to an explosion-proof casing for an electric core and an electric core. Background Art

[0002] The explosion-proof casing for an electric core is an electric core casing with an explosion-proof valve, and this casing can effectively improve the safety of the electric core. The explosion-proof valve made of pure aluminum can effectively improve the accuracy of the bursting value. However, due to the relatively soft pure aluminum material, when the explosion-proof valve is welded to the electric core casing, the explosion-proof valve is prone to deformation, and the stability of its bursting pressure depends on the quality of the welding process. Therefore, the use of an explosion-proof valve made of pure aluminum has high requirements for the welding process and low process yield, which is not conducive to mass production.

[0003] At the same time, in the prior art, the position of the explosion-proof valve is generally set on the top cover of the electric core. However, since the top cover of the electric core is located at one end of the length direction of the electric core, the path for gas to reach the explosion-proof valve is relatively long, which is not conducive to improving the safety of the electric core. Setting the explosion-proof valve on the side wall of the casing body can shorten the exhaust path and improve the safety performance. However, compared with the top cover, the wall thickness of the side wall of the casing body is smaller, and in order to arrange the explosion-proof valve, an opening needs to be made on the side wall of the casing body, and the structural strength at the opening is further reduced. Therefore, the structure of the casing body at the welding position of the explosion-proof valve is weak, and welding is likely to cause deformation of the casing, resulting in rubbing of the electrode group when entering the casing, affecting the subsequent assembly and use of the electric core. Summary of the Invention

[0004] An object of the present invention is to provide an explosion-proof casing for an electric core, which can avoid deformation of the explosion-proof valve and the casing body, ensure that the accuracy of the explosion-proof valve remains unchanged, and enable the electrode group to smoothly enter the casing.

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

[0006] Provide an explosion-proof casing for an electric core, including:

[0007] A casing body having a first side wall, and an explosion-proof through hole and a first fixing through hole are formed on the first side wall;

[0008] An explosion-proof integrated part, the explosion-proof integrated part covers the first side wall, the explosion-proof integrated part includes an explosion-proof part and a fixing part, the projection of the explosion-proof part towards the first side wall is located in the explosion-proof through hole, the fixing part is provided with a second fixing through hole, and the two ends of the second fixing through hole along its own axial direction are respectively a first opening and a second opening, the area of the first opening is larger than the area of the second opening, and the second opening faces the first side wall;

[0009] A fixing member, the fixing member having a connected first part, a second part, and a third part, the first part filling the second fixing through hole, the second part filling the first fixing through hole, and the third part at least partially abutting against the wall surface of the first side wall facing the inner cavity of the cell explosion-proof housing.

[0010] Optionally, the fixing member is an injection molded part. The two ends of the first fixing through hole along its own axis are respectively a third opening and a fourth opening. The third opening is closer to the explosion-proof integrated part than the fourth opening. Both the second opening and the third opening are circular. The diameter of the second opening is D2, and the diameter of the third opening is D1, and they satisfy 0 ≤ D2 - D1 ≤ 1.1 mm.

[0011] Optionally, the second fixing through hole is a frustum-shaped through hole, and the angle F2 between the extension surface of the side wall of the frustum-shaped through hole and the axis of the frustum-shaped through hole itself satisfies F2 ≥ 15°.

[0012] Optionally, the thickness T of the fixing part satisfies 1.5 mm < T < 2.5 mm.

[0013] Optionally, a limiting ring is convexly provided on the wall surface of the first side wall facing the inner cavity of the cell explosion-proof housing. The limiting ring is arranged around the first fixing through hole, and the third part is completely wrapped around the limiting ring.

[0014] Optionally, the angle F1 between the outer side wall of the limiting ring and the wall surface of the first side wall facing the inner cavity of the cell explosion-proof housing satisfies 66° < F1 ≤ 78°.

[0015] Optionally, the third part has a first end face, the first end face is arranged facing the inner cavity of the cell explosion-proof housing, and the first end face is parallel to the first side wall.

[0016] Optionally, it further includes a sealing ring, the sealing ring is clamped between the explosion-proof integrated part and the first side wall, and the sealing ring is arranged around the explosion-proof part and the explosion-proof through hole.

[0017] Optionally, it includes a fixed sealing member, the fixed sealing member includes the connected sealing ring and the fixing member, and the fixed sealing member is an injection molded one-piece part.

[0018] Another object of the present invention is to provide a cell that can avoid deformation of the explosion-proof valve and the shell body, ensure that the accuracy of the explosion-proof valve remains unchanged, and enable the electrode group to smoothly enter the shell.

[0019] To achieve this purpose, the present invention adopts the following technical solutions:

[0020] Provided is a battery cell, comprising a battery cell top cover, a pole group and the above-mentioned battery cell explosion-proof shell, wherein the battery cell top cover sealing cover is arranged at the opening of the battery cell explosion-proof shell to form an outer shell of the battery cell, and the pole group is arranged in the outer shell.

[0021] Beneficial effects of the present invention:

[0022] The present invention provides an explosion-proof shell of a battery core, comprising a shell body, an explosion-proof integrated part and a fixing part. The shell body has a first side wall, and an explosion-proof through hole and a first fixed through hole are provided on the first side wall. The explosion-proof integrated part is covered on the first side wall, and the explosion-proof integrated part comprises an explosion-proof part and a fixing part, and the projection of the explosion-proof part toward the first side wall is located in the explosion-proof through hole, and the fixing part is provided with a second fixed through hole, and the two ends of the second fixed through hole along its own axis are respectively a first opening and a second opening, and the area of ​​the first opening is greater than the area of ​​the second opening, and the second opening faces the first side wall. The fixing part has a first part, a second part and a third part connected to each other, the first part fills the second fixed through hole, the second part fills the first fixed through hole, and the third part at least partially abuts against the wall of the first side wall facing the inner cavity of the explosion-proof shell of the battery core. Since the first part fills the second fixed through hole, and the opening area of ​​the second fixed through hole away from the first side wall is larger, the first part can limit the movement of the explosion-proof integrated part in the direction away from the first side wall. And because the third part at least partially abuts against the wall of the first side wall facing the inner cavity of the explosion-proof shell of the battery cell, it can be ensured that the fixing member will not be separated from the first side wall, and the explosion-proof integrated member can be fixed on the first side wall. The above fixing method can replace the method of welding the explosion-proof valve and the first side wall, which can avoid deformation of the explosion-proof valve and the first side wall caused by welding, thereby ensuring that the blasting accuracy of the explosion-proof valve is not affected, and the pole group will not be scratched when entering the shell.

[0023] The present invention also provides a battery cell, comprising a battery cell top cover, a pole group and the above-mentioned battery cell explosion-proof shell, wherein the battery cell top cover sealing cover is arranged at the opening of the battery cell explosion-proof shell to form the shell of the battery cell, and the pole group is arranged in the shell. The battery cell can avoid deformation of the explosion-proof valve and the shell body, ensure that the accuracy of the explosion-proof valve remains unchanged, and the pole group is smoothly inserted into the shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the explosion-proof housing of a battery cell provided in an embodiment of the present invention;

[0025] Figure 2 is an exploded view of the explosion-proof casing of the battery cell provided in an embodiment of the present invention;

[0026] Figure 3 yes Figure 2 The enlarged view of point A in the middle;

[0027] Figure 4 It is a schematic diagram of the structure of the explosion-proof housing and pole group of the battery cell provided in an embodiment of the present invention;

[0028] Figure 5 is Figure 4 Cross-sectional view taken along line B-B in

[0029] Figure 6 is Figure 5 Enlarged view at location C in

[0030] Figure 7 is Figure 4 Cross-sectional view taken along line D-D in

[0031] Figure 8 is Figure 7 Enlarged view at location E in

[0032] Figure 9 It is a schematic structural diagram of the explosion-proof integrated part provided by the embodiment of the present invention.

[0033] In the figure:

[0034] 1. Housing body; 11. First side wall; 111. Explosion-proof through hole; 112. First fixing through hole; 113. First sealing limit groove; 114. Assembly limit groove; 115. Limit ring

[0035] 2. Explosion-proof integrated part; 21. Explosion-proof part; 22. Fixing part; 221. Second fixing through hole; 222. Second sealing limit groove

[0036] 3. Fixing seal; 31. Fixing piece; 311. First part; 312. Second part; 313. Third part; 3131. First end face; 32. Sealing ring

[0037] 100. Electrode group Specific embodiments

[0038] The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only for explaining the present invention, rather than limiting the present invention. In addition, it should be noted that for the convenience of description, only parts related to the present invention are shown in the drawings, rather than all of them.

[0039] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection; 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 inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0040] In the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include the first and second features not being in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is less than that of the second feature.

[0041] The explosion-proof housing of the battery cell, i.e., the battery cell housing with an explosion-proof valve, can effectively improve the safety of the battery cell. The explosion-proof valve made of pure aluminum can effectively improve the accuracy of the bursting value. However, due to the relatively soft pure aluminum material, when the explosion-proof valve is welded to the battery cell housing, the explosion-proof valve is prone to deformation, and the stability of its bursting pressure depends on the quality of the welding process. Therefore, the use of an explosion-proof valve made of pure aluminum has high requirements for the welding process and low process yield, which is not conducive to mass production.

[0042] Meanwhile, in the prior art, the position of the explosion-proof valve is generally set 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 improving the safety of the battery cell. Setting the explosion-proof valve on the side wall of the housing body can shorten the exhaust path and improve the safety performance. However, compared with the top cover, the wall thickness of the side wall of the housing body is smaller, and in order to arrange the explosion-proof valve, an opening needs to be made on the side wall of the housing body, and the structural strength at the opening is further reduced. Therefore, the structure of the housing body at the welding position of the explosion-proof valve is weak, and welding is likely to cause deformation of the housing, resulting in rubbing of the electrode assembly when it enters the housing, affecting the subsequent assembly and use of the battery cell.

[0043] Therefore, the present embodiment provides an explosion-proof housing for a battery cell to solve the above problems. The explosion-proof housing for the battery cell can avoid deformation of the explosion-proof valve and the housing body 1, ensure that the accuracy of the explosion-proof valve remains unchanged, and enable the electrode assembly 100 to smoothly enter the housing.

[0044] Such as Figures 1 - 9As shown in the figure, the explosion-proof housing of the battery cell in this embodiment includes a housing body 1, an explosion-proof integrated part 2, and a fixing part 31. Among them, the housing body 1 has a first side wall 11, and an explosion-proof through hole 111 and a first fixing through hole 112 are provided on the first side wall 11. The explosion-proof integrated part 2 is covered on the first side wall 11. The explosion-proof integrated part 2 includes an explosion-proof part 21 and a fixing part 22. The projection of the explosion-proof part 21 facing the first side wall 11 is located within the explosion-proof through hole 111. The fixing part 22 is provided with a second fixing through hole 221. The two ends of the second fixing through hole 221 along its own axial direction are respectively a first opening and a second opening. The area of the first opening is larger than that of the second opening, and the second opening faces the first side wall 11. The fixing part 31 has a first part 311, a second part 312, and a third part 313 connected to each other. The first part 311 fills the second fixing through hole 221, the second part 312 fills the first fixing through hole 112, and the third part 313 at least partially abuts against the wall surface of the first side wall 11 facing the inner cavity of the explosion-proof housing of the battery cell.

[0045] Since the first part 311 fills the second fixing through hole 221 and the opening area of the second fixing through hole 221 facing away from the first side wall 11 is larger, the first part 311 can limit the movement of the explosion-proof integrated part 2 in the direction away from the first side wall 11. And because the third part 313 at least partially abuts against the wall surface of the first side wall 11 facing the inner cavity of the explosion-proof housing of the battery cell, it can ensure that the fixing part 31 will not break away from the first side wall 11, and the explosion-proof integrated part 2 can be fixed on the first side wall 11. The above fixing method can replace the method of welding and fixing the explosion-proof valve to the first side wall 11, which can avoid the deformation of the explosion-proof valve and the first side wall 11 caused by welding, so as to ensure that the blasting accuracy of the explosion-proof valve is not affected, and the electrode group 100 will not be scratched when entering the housing.

[0046] Optionally, an assembly limiting groove 114 is provided on the outer wall surface of the first side wall 11. The explosion-proof integrated part 2 is located within the assembly limiting groove 114, which is convenient for positioning and limiting during assembly. It can be known that both the explosion-proof through hole 111 and the first fixing through hole 112 are provided at the bottom of the assembly limiting groove 114.

[0047] Optionally, the first side wall 11 is one of the two side walls of the housing body 1 arranged oppositely along its own width direction. The explosion-proof integrated part 2 is arranged here to shorten the exhaust path and improve the safety performance of the battery cell.

[0048] Optionally, the length direction of the explosion-proof part 21, the length direction of the explosion-proof integrated part 2, and the length direction of the first side wall 11 are all consistent with the length direction of the housing body 1. The assembly limiting groove 114 is located in the middle of the first side wall 11 along its own length direction, which can further shorten the exhaust path.

[0049] Optionally, the housing body 1 is processed and formed by processes such as extrusion and high-frequency welding, which can ensure the structural strength of the housing body 1 and the airtightness of the connection.

[0050] Optionally, the thickness of the explosion-proof part 21 is smaller than that of the fixing part 22, and the thickness of the weak area of the explosion-proof part 21 is even smaller. When the battery cell undergoes thermal runaway, the weak area of the explosion-proof part 21 explodes, forming a directional exhaust to prevent the battery cell from exploding.

[0051] Optionally, the explosion-proof integral part 2 is processed by an integral stamping process. The material of the explosion-proof integral part 2 can be aluminum or other materials.

[0052] Optionally, the material of the explosion-proof part 21 can be the same as or different from that of the fixing part 22. Further optionally, in this embodiment, the material of the explosion-proof part 21 is MXF2, and the material of the fixing part 22 is aluminum.

[0053] Optionally, the fixing member 31 is an injection-molded part. Optionally, the two ends of the first fixing through-hole 112 along its own axial direction are respectively a third opening and a fourth opening. The third opening is closer to the explosion-proof integral part 2 than the fourth opening. Both the second opening and the third opening are circular. The diameter of the second opening is D2, and the diameter of the third opening is D1, and they satisfy 0≤D2 - D1≤1.1mm. During the process of assembling the explosion-proof integral part 2 onto the first side wall 11, when the fixing part 22 fits against the bottom of the assembly limiting groove 114, the second opening and the third opening are arranged in relative communication. In this embodiment, the third opening completely falls within the range of the second opening, and their axes coincide. Since the glue enters from the outside during injection molding, that is, the glue will first enter the second fixing through-hole 221 and then enter the first fixing through-hole 112. Ensuring D2 - D1≥0, that is, the diameter of the second opening is greater than or equal to the diameter of the third opening. Such a setting helps to ensure that when the glue enters the first fixing through-hole 112 from the second fixing through-hole 221, there is also glue at the inner wall near the first fixing through-hole 112, that is, there is no gap between the glue and the inner wall of the first fixing through-hole 112, which helps to ensure airtightness. However, if the difference between D2 and D1 is greater than 1.1mm, that is, the difference between them is too large, either the diameter D2 of the second opening is too large, and the glue is not easy to fill the second fixing through-hole 221, so that there is a gap at the inner wall of the second fixing through-hole 221, which will also cause airtightness problems. Or the diameter D1 of the third opening is too small, which will cause the connection part between the second part 312 and the first part 311 to be too thin, and the structural strength here is insufficient, easily resulting in insufficient anti-pushing performance of the explosion-proof integral part 2. In addition, too large a difference between D2 and D1 will also cause too much resistance during glue injection, which is not conducive to the operation of the injection molding process and will also affect the molding efficiency.

[0054] Optionally, the first fixing through-hole 112 is a cylindrical through-hole, that is, both the third opening and the fourth opening are circular and have the same size.

[0055] Such as Figure 6 and Figure 8As shown, optionally, a limiting ring 115 is convexly provided on the wall surface of the first side wall 11 facing the inner cavity of the battery cell explosion-proof housing. The limiting ring 115 is arranged around the first fixing through hole 112. Optionally, the limiting ring 115 is coaxially arranged with the first fixing through hole 112. The third part 313 is completely wrapped around the limiting ring 115, that is, the inside, outside and the end part facing the electrode group 100 of the limiting ring 115 are all wrapped by the third part 313. It can be known that such a setting can limit the radial movement of the third part 313 along the limiting ring 115 through the limiting ring 115.

[0056] Optionally, the inner side wall of the inner ring of the limiting ring 115 and the inner wall of the first fixing through hole 112 are on an annular surface, that is, the inner side wall of the inner ring of the limiting ring 115 is perpendicular to the plane where the first side wall 11 is located.

[0057] Optionally, the included angle F1 between the outer side wall of the limiting ring 115 and the wall surface of the first side wall 11 facing the inner cavity of the battery cell explosion-proof housing satisfies 66° < F1 ≤ 78°, that is, compared with the plane where the first side wall 11 is located, the outer side wall of the limiting ring 115 is inclined. Optionally, the limiting ring 115 is a circular ring, and the diameter of the end surface of the limiting ring 115 close to the electrode group 100 is larger than the diameter of the end surface of the limiting ring 115 fitting the first side wall 11, which can form a barb structure, further strengthening the limiting ability of the limiting ring 115 on the third part 313, preventing the edge of the third part 313 from tilting towards the electrode group 100, ensuring that the third part 313 closely adheres to the inner wall of the first side wall 11, and the above setting can also extend the air leakage path at the gap between the fixing part 31 and the first side wall 11, improving the air tightness here.

[0058] If the included angle F1 is less than or equal to 66°, the difficulty of the injection molding process will increase, the glue is not easy to enter the root of the outer side wall of the limiting ring 115, and it is easy to cause defects. However, if the included angle F1 is greater than 78°, the barb limiting effect of the limiting ring 115 on the third part 313 is not good. When the explosion-proof integrated part 2 is stressed, the edge of the third part 313 is still easy to tilt towards the electrode group 100, forming a gap between the third part 313 and the inner wall of the first side wall 11, resulting in a decrease in air tightness. Moreover, the fixing effect of the fixing part 31 is not good, and the explosion-proof integrated part 2 is easy to be loosened by force.

[0059] Optionally, the third part 313 has a first end surface 3131, and the first end surface 3131 faces the inner cavity of the battery cell explosion-proof housing. The first end surface 3131 is parallel to the first side wall 11 to fit the wall surface of the electrode group 100, preventing the third part 313 from having a tip to scratch the electrode group 100. And the third part 313 can also support the electrode group 100, keeping the gap size between the electrode group 100 and the first side wall 11 unchanged, preventing the electrode group 100 from blocking the first fixing through hole 112, resulting in the explosion-proof part 21 being unable to explode normally.

[0060] Optionally, the outer shape of the third part 313 is cylindrical, and the connection between the side wall of the third part 313 and the first end face 3131 is a curved surface to further prevent damage to the electrode group 100. The bottom surface of the third part 313 fits against the inner wall surface of the first side wall 11, and the third part 313 has an annular groove, and the limiting ring 115 is located in the annular groove.

[0061] As Figure 6 and Figure 8 shown, in this embodiment, optionally, the second fixing through hole 221 is a frustum-shaped through hole, and the included angle F2 between the extension surface of the side wall of the frustum-shaped through hole and the axial direction of the frustum-shaped through hole itself satisfies F2≥15°. When the included angle F2 is less than 15°, the limiting effect between the first part 311 and the explosion-proof integrated part 2 is poor, the anti-thrust performance of the explosion-proof integrated part 2 is poor, and it is easy to generate a gap between the explosion-proof integrated part 2 and the first side wall 11, resulting in poor airtightness.

[0062] Of course, in other embodiments, a stepped surface may also be provided in the second fixing through hole 221, and the stepped surface is arranged facing the outside of the battery cell, which can also form a limiting effect on the explosion-proof integrated part 2 to prevent the explosion-proof integrated part 2 from detaching from the first side wall 11. However, the setting method of this embodiment is more conducive to glue injection, reduces the glue injection resistance, and improves the efficiency and quality of injection molding.

[0063] Optionally, the thickness T of the fixing part 22 satisfies 1.5mm < T < 2.5mm. If the thickness T of the fixing part 22 is too small, the structural strength will be insufficient and the anti-thrust performance will be poor. If the thickness T of the fixing part 22 is too large, the cost will increase. Therefore, 1.5mm < T < 2.5mm is a better value condition.

[0064] Optionally, in order to prevent a gap between the explosion-proof integrated part 2 and the first side wall 11, resulting in poor airtightness, the battery cell explosion-proof housing further includes a sealing ring 32, and the sealing ring 32 is clamped between the explosion-proof integrated part 2 and the first side wall 11, and the sealing ring 32 is arranged around the explosion-proof part 21 and the explosion-proof through hole 111.

[0065] Optionally, a first sealing limiting groove 113 is formed on the bottom of the assembly limiting groove 114 of the first side wall 11, and a part of the sealing ring 32 is located in the first sealing limiting groove 113. As Figure 9 shown, a second sealing limiting groove 222 is formed on the end face of the explosion-proof integrated part 2 facing the first side wall 11, and a part of the sealing ring 32 is located in the second sealing limiting groove 222.

[0066] Optionally, the battery cell explosion-proof housing includes a fixed sealing member 3, and the fixed sealing member 3 includes a sealing ring 32 and a fixing member 31 connected to each other. The fixed sealing member 3 is an injection-molded integral part. As Figure 3As shown, the sealing ring 32 and the fixing member 31 are two parts of one piece. The sealing ring 32 and the fixing member 31 are cross-connected. Specifically, part of the sealing ring 32 crosses the first part 311, and part crosses the second part 312. The first sealing limit groove 113 and the second sealing limit groove 222 are butted to form a cavity for the sealing ring 32, which can be used for the injection molding of the sealing ring 32. The fixed sealing member 3 can be injection molded at one time, eliminating the processes of separately molding or separately assembling the fixing member 31 and the sealing ring 32, and can also improve production efficiency. Optionally, in this embodiment, the nano-injection molding process is used to process the fixed sealing member 3 to ensure the dimensional accuracy of the fixed sealing member 3.

[0067] Further optionally, in order to ensure that the connection strength between the explosion-proof integrated part 2 and the first side wall 11 is relatively consistent everywhere, two fixing members 31 are provided. And since the sealing ring 32, the explosion-proof part 21, and the explosion-proof through hole 111 are all elliptical, the length directions of the sealing ring 32, the explosion-proof part 21, and the first side wall 11 are all the same as the length direction of the shell body 1, so the two fixing members 31 are respectively located at both ends of the length direction of the sealing ring 32. Of course, in other embodiments, one, three, four or more fixing members 31 can also be provided, which can be adjusted according to actual situations.

[0068] Optionally, the material of the fixed sealing member 3 is a modified PPS material, which has good high-temperature resistance.

[0069] In order to verify whether the airtightness, anti-pushing and anti-twisting performance, etc. at the explosion-proof part 21 of the battery cell explosion-proof housing meet the quality requirements of the battery cell, this embodiment provides a set of test data as shown in Table 1 and Table 2 below. Table 1 lists the dimensions of the battery cell explosion-proof housings of six groups of examples, and Table 2 lists the dimensions of the battery cell explosion-proof housings of five groups of comparative examples. The same point of the battery cell explosion-proof housings of the six groups of examples and the five groups of comparative examples is that the diameter D2 of the second opening is 3.6 mm, and the difference between the battery cell explosion-proof housings of the six groups of examples and the five groups of comparative examples is only in size.

[0070] For each of the key dimensional parameters of the explosion-proof housing of the six groups of examples in Table 1, they all meet the above-mentioned more optimal value range. For example, the diameter D2 of the second opening and the diameter D1 of the third opening satisfy 0 ≤ D2 - D1 ≤ 1.1 mm, the angle F1 between the outer sidewall of the limiting ring 115 and the wall surface of the first sidewall 11 facing the inner cavity of the explosion-proof housing of the battery cell satisfies 66° < F1 ≤ 78°, the angle F2 between the extension surface of the sidewall of the frustum-shaped through hole and the self-axis of the frustum-shaped through hole satisfies F2 ≥ 15°, and the thickness T of the fixing part 22 satisfies 1.5 mm < T < 2.5 mm. After testing, neither the explosion-proof part 21 nor the fixing part 22 of the explosion-proof integrated part 2 of the explosion-proof housing of the six groups of examples is deformed. The bursting value of the explosion-proof part 21 meets the preset pressure range, the anti-pushing and anti-twisting performance of the fixing part 22 also meets the quality requirements of the battery cell, and the airtightness test at the explosion-proof integrated part 2 is qualified without air leakage. That is, the explosion-proof housing of the battery cell that meets the above-mentioned more optimal dimensional range has no deformation problem at all. The housing body 1 will not be concave inward, and the electrode group 100 will not be scratched when inserted into the housing. The fixed seal 3 can completely achieve the firm connection of the explosion-proof integrated part 2 on the first sidewall 11, and there is no need to adopt the welding process anymore. Moreover, the fixed seal 3 can also ensure that the explosion-proof integrated part 2 is closely attached to the first sidewall 11 with good airtightness.

[0071] Table 1

[0072] Category Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 D1 (mm) 2.5 2.7 2.9 3.1 3.3 3.6 D2 (mm) 3.60 3.60 3.60 3.60 3.60 3.60 F1 78° 78° 75° 72° 70° 68° F2 15° 15° 15° 15° 15° 15° T (mm) 1.80 1.80 1.80 1.80 1.80 1.80 D2 - D1 (mm) 1.10 0.90 0.70 0.50 0.30 0.00

[0073] Table 2

[0074] Category Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 D1 (mm) 2.9 3.1 3.3 3.3 3.7 D2 (mm) 3.60 3.60 3.60 3.60 3.60 F1 80° 72° 70° 66° 70° F2 15° 12° 15° 15° 15° T (mm) 1.80 1.80 1.50 1.80 1.80 D2 - D1 (mm) 0.70 0.50 0.30 0.30 -0.10

[0075] For the explosion-proof housing of the battery cell in Comparative Example 1 in Table 2 above, the angle F1 between the outer sidewall of the limiting ring 115 and the wall surface of the first sidewall 11 facing the inner cavity of the explosion-proof housing of the battery cell does not meet the more optimal value range, and the angle F1 is 80°. After testing, the strength of the fixed seal 3 of this group of explosion-proof housings of the battery cell is low. Specifically, the limiting ability of the limiting ring 115 to the third part 313 is insufficient, and the anti-pushing performance of the explosion-proof integrated part 2 does not meet the design requirements. This group of explosion-proof housings of the battery cell has poor helium detection. Specifically, the qualified rate of helium detection is less than 98%.

[0076] For the explosion-proof housing of the battery cell in Comparative Example 2 in Table 2 above, the angle F2 between the extension surface of the sidewall of the frustum-shaped through hole and the self-axis of the frustum-shaped through hole does not meet the more optimal value range, and the angle F2 is 12°. After testing, the strength of the fixed seal 3 of this group of explosion-proof housings of the battery cell is also low. Specifically, the limiting ability of the first part 311 to the explosion-proof integrated part 2 is insufficient, and the anti-pushing performance of the explosion-proof integrated part 2 does not meet the design requirements. This group of explosion-proof housings of the battery cell has poor helium detection. Specifically, the qualified rate of helium detection is less than 98%.

[0077] The thickness T of the fixing part 22 of the explosion-proof housing of the battery cell in Comparative Example 3 in Table 2 above does not meet the more optimal value range, and the thickness T of the fixing part 22 is 1.5 mm. After inspection, the structural strength of the fixing part 22 of this group of battery cell explosion-proof housings is relatively low, and the anti-thrust of the fixing part 22 does not meet the design requirements. Similarly, defects occur during helium leak detection, and the qualified rate of helium leak detection is also less than 98%.

[0078] The included angle F1 between the outer side wall of the limiting ring 115 of the explosion-proof housing of the battery cell in Comparative Example 4 in Table 2 above and the wall surface of the first side wall 11 facing the inner cavity of the explosion-proof housing of the battery cell does not meet the more optimal value range, and the included angle F1 is 66°. After inspection, both the helium leak detection of this group of battery cell explosion-proof housings and the bursting value of the explosion-proof part 21 meet the quality requirements. However, the processing difficulty of the limiting ring 115 of this group of battery cell explosion-proof housings is too large, which will also increase the difficulty of the injection molding process. It is not easy for the glue to enter the root of the outer side wall of the limiting ring 115. Compared with the explosion-proof housing of the battery cell in the example, the yield rate of this group of battery cell explosion-proof housings is reduced.

[0079] The diameter D1 of the third opening of the explosion-proof housing of the battery cell in Comparative Example 5 in Table 2 above is 3.7 mm, and the difference between D2 and D1 is less than 0, which does not meet the more optimal value range. After inspection, the injection molding fixing force of the fixing seal 3 of this group of battery cell explosion-proof housings is insufficient, and the anti-thrust performance of the explosion-proof integral part 2 does not meet the design requirements. This group of battery cell explosion-proof housings has defects in helium leak detection. Specifically, the qualified rate of helium leak detection is less than 98%. This is because when injecting glue from the outside, the glue at the first fixing through hole 112 will have a thrust on the fixing part 22, which is not conducive to the fitting and sealing of the fixing part 22 and the first side wall 11, thus affecting the bonding strength between the explosion-proof integral part 2 and the first side wall 11. At the same time, it will also affect the flatness of the second part 312. The larger D1 is, the larger the contact surface between the second part 312 and the inner wall of the first fixing through hole 112 is. Once there are defects during plastic injection molding, there will be a risk of air leakage, affecting the airtightness here.

[0080] This embodiment also provides a battery cell, which includes a battery cell top cover, a pole group 100, and the above-mentioned explosion-proof housing of the battery cell. The battery cell top cover is hermetically covered at the opening of the explosion-proof housing of the battery cell to form the outer shell of the battery cell, and the pole group 100 is arranged inside the outer shell. This battery cell can prevent the explosion-proof valve and the shell body 1 from deforming, ensure that the accuracy of the explosion-proof valve remains unchanged, and enable the pole group 100 to smoothly enter the shell.

[0081] The explosion-proof structure is no longer provided on the top cover of the battery cell. The explosion-proof integrated part 2 is provided on the shell body 1. When the battery cell undergoes thermal runaway, the path of valve-opening and gas exhaust will be shorter, thereby improving the safety performance of the battery cell. The explosion-proof housing of the battery cell forms a fixed seal 3 by injection molding. The fixing part 31 of the fixed seal 3 can firmly fix the explosion-proof integrated part 2 on the first side wall 11, and the sealing ring 32 part of the fixed seal 3 can achieve the sealed docking of the explosion-proof integrated part 2 and the first side wall 11 to ensure airtightness. Setting the fixed seal 3 can cancel the separate sealing structure, simplify the assembly process, avoid the risk of missing the sealing ring 32, and also avoid the influence of laser welding on the performance of the explosion-proof structure. Once the welding of the explosion-proof structure in the prior art is defective, the shell body 1 and the explosion-proof structure need to be directly scrapped. However, in this embodiment, the fixed seal 3 is formed by injection molding to fix the explosion-proof integrated part 2 and perform sealing. If there are defects during the molding process, both the explosion-proof integrated part 2 and the shell body 1 can be recycled, thereby reducing costs. And this battery cell is convenient for platform design and production, and can further reduce the cost of the battery cell. In addition, the third part 313 of the fixed seal 3 of this battery cell protrudes and cooperates with the electrode assembly 100, which can also prevent the electrode assembly 100 or other components from blocking the explosion-proof through hole 111 during thermal runaway, improving the safety of the battery cell.

[0082] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications 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, 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. The explosion-proof housing of the battery cell, characterized in that, Comprising: A housing body (1) having a first side wall (11), an explosion-proof through hole (111) and a first fixing through hole (112) being formed in the first side wall (11); An explosion-proof integral part (2) covering the first side wall (11), the explosion-proof integral part (2) including an explosion-proof portion (21) and a fixing portion (22), a projection of the explosion-proof portion (21) facing the first side wall (11) being located within the explosion-proof through hole (111), a second fixing through hole (221) being formed in the fixing portion (22), two ends of the second fixing through hole (221) along its own axial direction being a first opening and a second opening respectively, an area of the first opening being larger than an area of the second opening, and the second opening facing the first side wall (11); A fixing member (31) having a connected first part (311), a second part (312) and a third part (313), the first part (311) filling the second fixing through hole (221), the second part (312) filling the first fixing through hole (112), and the third part (313) at least partially abutting against a wall surface of the first side wall (11) facing the inner cavity of the battery cell explosion-proof housing.

2. The explosion-proof housing of the battery cell according to claim 1, characterized in that, The fixing member (31) is an injection-molded part, two ends of the first fixing through hole (112) along its own axial direction being a third opening and a fourth opening respectively, the third opening being closer to the explosion-proof integral part (2) than the fourth opening, both the second opening and the third opening being circular, a diameter of the second opening being D2, a diameter of the third opening being D1, and 0≤D2 - D1≤1.1mm being satisfied for the two.

3. The explosion-proof cell housing according to claim 1, characterized in that, The second fixing through hole (221) is a frustum-shaped through hole, an included angle F2 between an extension surface of a side wall of the frustum-shaped through hole and the axial direction of the frustum-shaped through hole itself satisfies F2≥15°.

4. The explosion-proof housing of the battery cell according to claim 1, wherein A thickness T of the fixing portion (22) satisfies 1.5mm<T<2.5mm.

5. The explosion-proof housing of the battery cell according to any one of claims 1-4, characterized in that, A limiting ring (115) is convexly provided on a wall surface of the first side wall (11) facing the inner cavity of the battery cell explosion-proof housing, the limiting ring (115) being arranged around the first fixing through hole (112), and the third part (313) being arranged to completely wrap the limiting ring (115).

6. The explosion-proof cell housing according to claim 5, characterized in that, An included angle F1 between an outer side wall of the limiting ring (115) and a wall surface of the first side wall (11) facing the inner cavity of the battery cell explosion-proof housing satisfies 66°<F1≤78°.

7. The explosion-proof housing of the battery cell according to any one of claims 1-4, characterized in that The third part (313) has a first end face (3131), the first end face (3131) facing the inner cavity of the battery cell explosion-proof housing, and the first end face (3131) being parallel to the first side wall (11).

8. The explosion-proof cell housing according to any one of claims 1-4, characterized in that, Also included is a sealing ring (32), the sealing ring (32) being clamped between the explosion-proof integral part (2) and the first side wall (11), and the sealing ring (32) being arranged around the explosion-proof portion (21) and the explosion-proof through hole (111).

9. The explosion-proof cell housing according to claim 8, characterized in that, It includes a fixed seal (3), and the fixed seal (3) includes the connected sealing ring (32) and the fixing member (31), and the fixed seal (3) is an injection-molded integral part.

10. The battery cell is characterized in that, It includes a battery cell top cover, a pole group (100), and the battery cell explosion-proof housing according to any one of claims 1-9. The battery cell top cover is hermetically covered at the opening of the battery cell explosion-proof housing to form the outer shell of the battery cell, and the pole group (100) is arranged inside the outer shell.

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