Battery cell cover plate assembly

Abstract

The application relates to the battery technical field, in particular to a battery cell cover plate assembly and a battery cell. The battery cell cover plate assembly comprises a cover plate and an explosion-proof valve. The cover plate is formed with an explosion-proof valve mounting hole, and the explosion-proof valve is mounted in the explosion-proof valve mounting hole. The inner side of the cover plate close to the pole group of the battery cell is formed with a support boss protruding towards the pole group side. The support boss is arranged close to the pole group side relative to the explosion-proof valve along a first preset direction, and the support boss is used for preventing the pole group from moving towards the explosion-proof valve side, so that the pole group cannot shield the explosion-proof valve. It can be seen that the support boss protruding towards the pole group side is arranged on the cover plate. When thermal runaway occurs in the battery cell, the lower insulating part such as the lower plastic melts and loses the supporting effect, and the pole group moves towards the cover plate under the impact of high-temperature and high-pressure airflow, the support boss limits the pole group, so that the pole group cannot block the explosion-proof valve, the exhaust effect of the explosion-proof valve is greatly improved, and the safety performance of the battery cell is ensured.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a cell cover assembly. Background Technology

[0002] Lithium-ion batteries are widely used in various fields such as transportation power supply, power storage, new energy storage power supply, aerospace and military industries due to their advantages such as large capacity, high operating voltage, strong charge retention, and long cycle life. The core component of a lithium-ion battery is the energy storage cell, which generally includes a cover plate, shell, bare cell insulating film, side plates, electrode assembly, and electrolyte. One commonly used type of energy storage cell is the blade energy storage cell, which generally has a larger capacity and higher safety requirements. Therefore, blade energy storage cells typically use electrodes on the same side, with the explosion-proof valve on the opposite side of the cover plate to achieve thermal and electrical separation and improve cell safety performance. When thermal runaway occurs, the explosion-proof valve opens to release pressure and vent air. As the pressure decreases, the plastic melts at high temperatures and loses its supporting function. Furthermore, under the impact of high-temperature and high-pressure airflow inside the cell, the electrode assembly will move towards the explosion-proof valve side, causing the front end of the electrode assembly to block the explosion-proof valve, greatly reducing the venting effect of the explosion-proof valve and reducing the safety performance of the cell. Summary of the Invention

[0003] The purpose of this application is to provide a cell cover assembly that, to a certain extent, solves the technical problem in the prior art where, when a cell experiences thermal runaway, the electrode assembly moves toward the explosion-proof valve under the impact of high-temperature and high-pressure airflow inside the cell, causing the front end of the electrode assembly to block the explosion-proof valve, greatly reducing the venting effect of the explosion-proof valve and reducing the safety performance of the cell.

[0004] This application provides a battery cell cover assembly, including: a cover plate and an explosion-proof valve; wherein, the cover plate has explosion-proof valve mounting holes extending through both sides along a first preset direction, and the explosion-proof valve is installed in the explosion-proof valve mounting holes; along the first preset direction, a support boss protruding towards the electrode group is formed on the inner side of the cover plate near the electrode group, and along the first preset direction, the support boss is disposed relative to the explosion-proof valve near the electrode group, and the support boss is used to prevent the electrode group from moving towards the explosion-proof valve along the first preset direction and thus blocking the explosion-proof valve.

[0005] In the above technical solution, the supporting boss is further configured as a multi-level step along the first preset direction, and along the direction toward the pole group, the area of ​​the projection of the outer contour of each step along the first preset direction gradually decreases, so that the supporting boss is gradually rising toward the pole group side.

[0006] In any of the above technical solutions, the supporting boss further includes a first step portion and a second step portion; wherein the first step portion and the second step portion are sequentially arranged and connected along the first preset direction, and the second step portion is arranged relative to the first step portion closer to the pole group side.

[0007] In any of the above technical solutions, the support boss is further formed on the cover plate by stamping.

[0008] In any of the above technical solutions, further, along the first preset direction, the thickness of the cover plate is T1, and T1 = 2.0-2.5 mm.

[0009] In any of the above technical solutions, the height of the first step portion along the first preset direction is H1, the thickness of the cover plate along the first preset direction is T1, and 0.7≤H1 / T1≤0.85.

[0010] In any of the above technical solutions, the wall thickness of the first step portion is T2, and T2 = 1.5-2.0 mm.

[0011] In any of the above technical solutions, the height of the second step portion along the first preset direction is H2, the wall thickness of the first step portion is T2, and 0.55≤H2 / T2≤0.75.

[0012] In any of the above technical solutions, the wall thickness of the second step portion is T3, and T3 = 1.2-1.6 mm.

[0013] In any of the above technical solutions, the height of the first step portion along the first preset direction is H1, the height of the second step portion along the first preset direction is H2, and 2.5mm≤H1+H2≤4.0mm.

[0014] In any of the above technical solutions, further, along the third preset direction, the explosion-proof valve is provided with the supporting bosses on opposite sides, and each of the supporting bosses extends along the second preset direction and is strip-shaped, and when the supporting boss is a multi-level step, each level of the step is strip-shaped.

[0015] In any of the above technical solutions, further, along the third preset direction, a plurality of support protrusions are respectively provided on the opposite sides of the explosion-proof valve, and the plurality of support protrusions on each side are sequentially spaced along the second preset direction, and the explosion-proof valve is located at the center of the enclosed area formed by the line connecting the plurality of support protrusions; along the third preset direction, two support protrusions are respectively provided on the opposite sides of the explosion-proof valve, and the enclosed area is rectangular.

[0016] In any of the above technical solutions, further, the distance between the two supporting bosses on one side of the explosion-proof valve along the third preset direction along the second preset direction is A3, the length of the explosion-proof valve mounting hole along the second preset direction is A0, and 0.35≤A3 / A0≤0.45.

[0017] In any of the above technical solutions, further, along the second preset direction, the length of the root of the supporting boss is A4, the length of the cover plate is A1, and 0.3≤2A4 / A1≤0.4.

[0018] In any of the above technical solutions, further, the distance between the two outer sides of the two supporting bosses on each side of the explosion-proof valve along the second preset direction and opposite to each other is A2, the length of the explosion-proof valve mounting hole along the second preset direction is A0, the height of the first step portion along the first preset direction is H1, the height of the second step portion along the first preset direction is H2, and 30≤(A2-A0) / [2×(H1+H2)]≤50.

[0019] In any of the above technical solutions, the width of the cover plate along the third preset direction is B1, and the distance between the two outer sides of the two corresponding support bosses that are opposite to each other along the third preset direction is B2, and 5mm≤(B1-B2) / 2≤8mm.

[0020] In any of the above technical solutions, further, along the third preset direction, the supporting bosses on opposite sides of the explosion-proof valve are symmetrically arranged with respect to the explosion-proof valve.

[0021] In any of the above technical solutions, the cell cover assembly further includes a lower insulating member, and along the first preset direction, the lower insulating member is installed on the inner side of the cover near the electrode group, and the lower insulating member forms an exhaust groove with an opening facing the cover side, and the exhaust groove is connected to the explosion-proof valve, and the support boss is located in the exhaust groove. The bottom wall of the exhaust groove along the first preset direction and close to the electrode group side has a first exhaust area, and the first exhaust area is correspondingly arranged with the explosion-proof valve along the first preset direction, and the first exhaust area is provided with a plurality of spaced first exhaust holes.

[0022] In any of the above technical solutions, the sum of the areas of the projections of all the first exhaust holes along the first preset direction is S1, the effective opening area of ​​the explosion-proof valve is S0, and S1 / S0≥0.55.

[0023] In any of the above technical solutions, further, along the second preset direction, at least one side wall of the exhaust groove is formed with a second exhaust through hole.

[0024] In any of the above technical solutions, further, along the third preset direction, at least one side wall of the exhaust groove is formed with a third exhaust through hole.

[0025] In any of the above technical solutions, further, the length of the lower insulating member along the second preset direction is L1, the length of the lower insulating member along the third preset direction is W1, the length of the third exhaust hole along the second preset direction is L2, the length of the second exhaust hole along the third preset direction is W2, and 0.4≤(2L2+2W2) / (L1+W1)≤0.7.

[0026] In any of the above technical solutions, further, a plurality of exhaust through holes are evenly distributed in the first exhaust area along the second preset direction and the third preset direction; the length of the third exhaust through hole along the second preset direction is L2, the length of the first exhaust area along the second preset direction is L3, and 0.5≤L2 / L3≤0.7.

[0027] In any of the above technical solutions, the thickness of the opposite side walls of the exhaust groove along the second preset direction is t1, and t1 = 1.2-2 mm.

[0028] In any of the above technical solutions, the thickness of the opposite side walls of the exhaust groove along the third preset direction is t2, and t2 = 1.0-1.5 mm.

[0029] In any of the above technical solutions, the overall height of the lower insulating member is H5, and H5 = 2.5-4.5mm.

[0030] In any of the above technical solutions, the explosion-proof valve and the first exhaust area are both waist-shaped and their shapes are compatible.

[0031] In any of the above technical solutions, the bottom wall of the exhaust groove is further provided with an exhaust grille area located on the side of the first exhaust area and spaced apart along a second preset direction, and the exhaust grille area is provided with transverse ribs and longitudinal ribs, and the transverse ribs extend along the second preset direction and the longitudinal ribs extend along a third preset direction.

[0032] In any of the above technical solutions, the thickness of the transverse rib along the third preset direction is t3, and t3 = 1.5-2.5 mm.

[0033] In any of the above technical solutions, the thickness of the longitudinal rib along the second preset direction is t4, and t4 = 1.5-2.5 mm.

[0034] In any of the above technical solutions, further, along the first preset direction, the projected area of ​​the outer contour of the exhaust grille area is S3, the sum of the projected areas of the transverse ribs and the longitudinal ribs is S2, and 0.45≤S2 / S3≤0.6.

[0035] In any of the above technical solutions, the distance between the root of the support boss located near the explosion-proof valve and the explosion-proof valve mounting hole along a direction perpendicular to the first preset direction is C1, and 4mm≤C1≤7mm.

[0036] In any of the above technical solutions, the explosion-proof valve is further located at the center of the cover plate, and the length direction of the explosion-proof valve is the same as the length direction of the cover plate, and the width direction of the explosion-proof valve is the same as the width direction of the cover plate.

[0037] In any of the above technical solutions, the first preset direction is the thickness direction of the cover plate, the second preset direction is the length direction of the cover plate, and the third preset direction is the width direction of the cover plate.

[0038] In any of the above technical solutions, the support boss is further positioned close to the explosion-proof valve mounting hole.

[0039] In any of the above technical solutions, the supporting boss is further defined as a rectangular structure, and when the supporting boss is a rectangular structure, each step is rectangular.

[0040] This application also provides a battery cell, including a housing, an electrode assembly, and a battery cell cover assembly as described in any of the above technical solutions, wherein the coated electrode assembly is installed inside the housing, and the battery cell cover assembly is installed at the open end of the housing. Therefore, it possesses all the beneficial technical effects of this battery cell cover assembly, which will not be elaborated further here.

[0041] In the above technical solution, the battery cell is further described as a blade battery cell.

[0042] Compared with the prior art, the beneficial effects of this application are as follows: This application provides a novel cell cover assembly, which has a support boss protruding towards the electrode group side on the cover. By reasonably limiting the position and size of the support boss on the cover, the problem of the upper electrode group moving and blocking the explosion-proof valve, thus affecting the venting effect of the explosion-proof valve, can be effectively avoided, thereby improving the safety performance of the cell. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the structure of the cover plate provided in an embodiment of this application; Figure 2 This is another structural schematic diagram of the cover plate provided in an embodiment of this application; Figure 3 Another structural schematic diagram of the cover plate provided in the embodiments of this application; Figure 4 for Figure 3 A magnified structural diagram at point A; Figure 5 This is a schematic diagram of the structure of the lower insulating member provided in an embodiment of this application; Figure 6 This is another structural schematic diagram of the lower insulating member provided in an embodiment of this application; Figure 7 Another structural schematic diagram of the lower insulating member provided in the embodiments of this application; Figure 8 This is a schematic diagram of the structure of the cell cover assembly provided in the embodiments of this application; Figure 9 Another structural schematic diagram of the cell cover assembly provided in an embodiment of this application.

[0045] Figure label: 1-Cover plate; 11-Support boss; 111-First step; 112-Second step; 113-Explosion-proof valve mounting hole; 114-Enclosed area; 2-Explosion-proof valve; 3-Lower insulating component; 31-Exhaust groove; 311-First exhaust through hole; 312-Second exhaust through hole; 313-Third exhaust through hole; 314-First exhaust area; 315-Exhaust grille area; 3151-Transverse rib; 3152-Longitudinal rib; a-First preset direction; b-Second preset direction; c-Third preset direction. Detailed Implementation

[0046] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0047] The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application.

[0048] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0049] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0050] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0051] The following reference Figures 1 to 9 This application describes a cell cover assembly according to some embodiments.

[0052] See Figures 1 to 4 As shown, an embodiment of this application provides a battery cell cover assembly, including: a cover plate 1 and an explosion-proof valve 2; wherein, the cover plate 1 has an explosion-proof valve mounting hole 113 extending through both sides along a first preset direction a, and the explosion-proof valve 2 is installed in the explosion-proof valve mounting hole 113; along the first preset direction a, a support boss 11 protruding toward the electrode group is formed on the inner side of the cover plate 1 near the electrode group, and along the first preset direction a, the support boss 11 is disposed relative to the explosion-proof valve 2 near the electrode group, and the support boss 11 is used to prevent the electrode group from moving toward the explosion-proof valve 2 along the first preset direction a and thus blocking the explosion-proof valve 2, that is, the support boss 11 is used to prevent the electrode group from moving toward the explosion-proof valve 2 along the first preset direction a, so that the electrode group cannot block the explosion-proof valve 2.

[0053] As can be seen from the structure described above, this application provides a novel battery cell cover assembly. A support boss 11 protruding towards the electrode group is provided on the cover 1. When thermal runaway occurs inside the battery cell, the lower insulating component 3, for example, the lower plastic melts and loses its supporting function. When the electrode group moves towards the cover 1 under the impact of high temperature and high pressure airflow, the support boss 11 will limit the electrode group, thereby preventing the electrode group from blocking the explosion-proof valve 2, greatly improving the exhaust effect of the explosion-proof valve 2, and ensuring the safety performance of the battery cell.

[0054] Furthermore, preferably, the first preset direction a is the thickness direction of the cover plate 1, the second preset direction b is the length direction of the cover plate 1, and the third preset direction c is the width direction of the cover plate 1, to meet the usage requirements. Of course, it is not limited to this, and the first preset direction a, the second preset direction b, and the third preset direction c can be selected according to actual needs. For example, the second preset direction b can also be the width direction of the cover plate 1, and the third preset direction c can also be the length direction of the cover plate 1, etc.

[0055] Furthermore, preferably, the explosion-proof valve 2 is located at the center of the cover plate 1, with the length direction of the explosion-proof valve 2 being the same as the length direction of the cover plate 1, and the width direction of the explosion-proof valve 2 being the same as the width direction of the cover plate 1. This layout is more reasonable, meets the usage requirements, and ensures the uniformity of exhaust on both sides. Of course, it is not limited to this.

[0056] Furthermore, preferably, the support boss 11 is positioned close to the explosion-proof valve mounting hole 113 to provide support and limit the electrode assembly in the area near the explosion-proof valve 2. This effectively prevents the electrode assembly near the explosion-proof valve 2 from blocking the explosion-proof valve 2 and meets the usage requirements. Of course, it is not limited to this. It can also be designed according to actual needs. For example, the support boss 11 can also be positioned away from the explosion-proof valve 2, which can also provide a certain support and limit effect on the entire electrode assembly and can also prevent the electrode assembly from blocking the explosion-proof valve 2.

[0057] Furthermore, preferably, the support boss 11 is formed on the cover plate 1 by stamping. It can be seen that the support boss 11 and the cover plate 1 are an integral structure with high overall strength and easy forming, which improves production efficiency. After stamping, the support boss 11 is in the shape of a boss on the inner side near the electrode group and in the shape of a groove on the outer side away from the electrode group, which helps to reduce weight. Of course, it is not limited to this. The support boss 11 can also be a structure independent of the cover plate 1 and fixed to the cover plate 1 by welding, gluing or other methods. Moreover, the support boss 11 can also be designed as a solid structure, that is, it is not a boss on one side, but a groove, etc., depending on the actual needs.

[0058] Furthermore, preferably, the support boss 11 is a rectangular structure, and when the support boss 11 is a rectangular structure, each step is rectangular, which meets the support requirements of the pole group, and the shape is regular, which is convenient for processing and manufacturing.

[0059] In one embodiment of this application, preferably, as Figure 1 As shown, the support boss 11 is a multi-level step arranged along the first preset direction a, and along the direction toward the pole group, the area of ​​the projection of the outer contour of each step along the first preset direction a gradually decreases, so that the support boss 11 is gradually rising toward the pole group side.

[0060] As can be seen from the structure described above, the supporting boss 11 is formed by stamping, using a multi-stage step-by-step forming process instead of a single stamping to reach the final height. Because the multi-stage step-by-step deformation results in a smaller deformation at each stage, the material changes more uniformly, significantly reducing the risk of failure and effectively preventing material cracking and wrinkling. In other words, it can effectively prevent metal sheets from cracking or wrinkling due to local stress concentration during a single stamping with a large deformation. Moreover, multi-stage stamping distributes the total deformation to multiple stations, significantly reducing the peak stamping force, reducing equipment load, and extending the service life of the mold. In other words, it can also reduce the stamping force and extend the mold life. In addition, it is difficult to accurately control springback and shape consistency in a single large deformation, while multi-stage forming allows for local correction and positioning after each process, gradually approaching the target shape, which can improve dimensional accuracy and stability.

[0061] In addition, the support boss 11 is designed as a multi-step structure with a larger root size to ensure sufficient strength and prevent breakage. The upper part, which is close to the electrode assembly, meets the limiting requirements of the electrode assembly while using less material, which helps to reduce material costs.

[0062] It should be noted that the support boss 11 may not be designed as a multi-step shape, but as another shape, such as having only one step, depending on the actual needs.

[0063] In one embodiment of this application, preferably, as Figure 1 As shown, the support boss 11 includes a first step portion 111 and a second step portion 112; wherein, the first step portion 111 and the second step portion 112 are sequentially arranged and connected along a first preset direction a, and the second step portion 112 is arranged relative to the first step portion 111 closer to the pole group side.

[0064] As can be seen from the structure described above, this application designs a two-stage step structure. The first-stage step at the root has sufficient thickness, i.e., width, to meet the strength requirements, while the second-stage step of the second layer can meet the limiting requirements of the pole group and help reduce material costs.

[0065] It should be noted that the supporting boss 11 is not limited to a two-step structure. It can also be a single-step structure or a structure with more than two steps, such as a three-step or four-step structure, or other shapes, depending on the actual needs.

[0066] Furthermore, preferably, the end faces of the first step portion 111 and the second step portion 112 near the electrode assembly are parallel to the end face of the electrode assembly near the explosion-proof valve 2, to meet the assembly requirements, but of course, it is not limited to this.

[0067] In one embodiment of this application, preferably, as Figure 4 As shown, along the first preset direction a, the thickness of the cover plate 1 is T1, and T1 = 2.0-2.5 mm.

[0068] Based on the structure described above, the thickness T1 of the cover plate 1, within the optimal range of 2.0-2.5mm, meets the strength requirements, is less prone to damage, has a longer service life, and satisfies the requirement for the stamped support boss 11. Of course, T1 is not limited to the optimal range of 2.0-2.5mm; it can also be <2.0mm or >2.5mm, depending on the actual needs.

[0069] In one embodiment of this application, preferably, as Figure 4 As shown, the height of the first step portion 111 along the first preset direction a is H1, and the thickness of the cover plate 1 along the first preset direction a is T1, and 0.7≤H1 / T1≤0.85.

[0070] Based on the structure described above, it can be seen that if the ratio of H1 / T1 is too small, it means that the height of the first step 111 is too small, resulting in poor limiting effect on the pole group. If the ratio of H1 / T1 is too large, it means that the thickness of the cover plate 1 is too small, which can easily lead to cracking and wrinkling during the stamping process of the stamping support boss 11, thus reducing the yield. Therefore, H1 / T1 should be set within the above-mentioned optimal range to ensure the limiting effect on the pole group and to prevent cracking and wrinkling during the stamping process, thereby ensuring the yield.

[0071] Of course, H1 / T1 is not limited to the above optimal range. H1 / T1 can also be set to <0.7 or >0.85, depending on the actual needs.

[0072] In one embodiment of this application, preferably, as Figure 4 As shown, the wall thickness of the first step portion 111 is T2 (not shown in the figure), and T2 = 1.5-2.0 mm.

[0073] As described above, the wall thickness T2 of the first step portion 111 is within the optimal range of 1.5-2.0 mm, ensuring sufficient strength and allowing the second step portion 112, mounted on the first step portion 111, to have sufficient thickness (i.e., width). This guarantees the strength of the second step portion 112, improves its limiting effect on the electrode assembly, and increases the contact area between the second step portion 112 and the electrode assembly, further enhancing its support and limiting effect. Of course, T2 is not limited to the optimal range of 1.5-2.0 mm; it can also be <1.5 mm or >2.0 mm, depending on the specific needs.

[0074] It should be noted that since the first step portion 111 and the second step portion 112 are stamped structures, they have a shell structure and therefore have a wall thickness.

[0075] In one embodiment of this application, preferably, as Figure 4 As shown, the height of the second step portion 112 along the first preset direction a is H2, the wall thickness of the first step portion 111 is T2 (not shown in the figure), and 0.55≤H2 / T2≤0.75.

[0076] Based on the structure described above, if the ratio of H2 / T2 is too small, it indicates that the height of the second step 112 is too small, resulting in poor limiting effect on the electrode assembly. If the ratio of H2 / T2 is too large, it indicates that the wall thickness of the first step is too small, which can easily lead to cracking and wrinkling during the stamping of the second step 112, thus reducing the yield. Therefore, H2 / T2 should be set within the above-mentioned optimal range to ensure the limiting effect on the electrode assembly and to prevent cracking and wrinkling during the stamping of the second step 112, thereby ensuring the yield.

[0077] Of course, H2 / T2 is not limited to the above optimal range. H2 / T2 can also be set to <0.55 or >0.75, depending on the actual needs.

[0078] In one embodiment of this application, preferably, as Figure 4 As shown, the wall thickness of the second step portion 112 is T3 (not shown in the figure), and T3 = 1.2-1.6 mm.

[0079] As described above, the thickness T3 of the second step portion 112 is within the optimal range of 1.2-1.6 mm, ensuring sufficient strength to enhance its support and limiting effect on the electrode assembly. It also increases the contact area between the second step portion 112 and the electrode assembly, further improving the support and limiting effect. However, T3 is not limited to the optimal range of 1.2-1.6 mm; it can also be <1.2 mm or >1.6 mm, depending on the specific requirements.

[0080] In one embodiment of this application, preferably, as Figure 4 As shown, the height of the first step portion 111 along the first preset direction a is H1, and the height of the second step portion 112 along the first preset direction a is H2, and 2.5mm≤H1+H2≤4.0mm.

[0081] Based on the structure described above, if the sum of the heights of the first step 111 and the second step 112 is too small, the supporting effect of the electrode group is poor, that is, the limiting effect of the electrode group is poor, the cell safety test fails, and the cell disassembly reveals that there are still slight traces of movement in the electrode group, which may cause the explosion-proof valve 2 to be blocked. If the sum of the heights of the first step 111 and the second step 112 is too large, it occupies a large space in the height direction of the cell, which may deepen the venting groove 31 of the lower insulation 3, affecting the strength of the lower insulation 3 itself, and may also occupy the space of the electrode group, resulting in a decrease in the capacitance of the electrode group. Therefore, the sum of the heights of the first step 111 and the second step 112 should be taken within the above-mentioned optimal range of 2.5-4.0mm. This can effectively avoid the problem of the electrode group moving and blocking the explosion-proof valve 2 during thermal runaway, and at the same time, it can also avoid the problem of occupying too much space in the height direction of the cell, thus preventing the venting groove 31 of the lower insulation 3 from being deepened, ultimately ensuring the strength of the insulation itself, and not occupying the space of the electrode group, thereby ensuring the capacitance of the electrode group.

[0082] Of course, H1+H2 is not limited to the optimal range of 2.5-4.0mm mentioned above. It can also be set to H1+H2<2.5mm or H1+H2>4.0mm, depending on the actual needs.

[0083] In one embodiment of this application, preferably, as Figure 2 As shown, along the third preset direction c, two support protrusions 11 are respectively provided on opposite sides of the explosion-proof valve 2, and the two support protrusions 11 on each side are arranged sequentially at intervals along the second preset direction b. Each support protrusion 11 extends along the second preset direction b and is strip-shaped. When the support protrusion 11 is a multi-level step, each level of the step is strip-shaped.

[0084] As can be seen from the structure described above, support bosses 11 are provided on both sides of the explosion-proof valve 2, which provide all-round support and limit the structure of the electrode group below the explosion-proof valve 2, preventing the electrode group from tilting and obstructing part of the explosion-proof valve 2, and further ensuring the safety and reliability of the battery cell. Moreover, multiple limiting protrusions are arranged in a large space on both sides of the explosion-proof valve 2 along the third preset direction c, which are arranged sequentially along the second preset direction b and extend along the second preset direction b, increasing the contact area between the support bosses 11 on each side and the electrode group, further improving the support and limiting effect on the electrode group. In addition, each step is strip-shaped, which makes the contact area between each support boss 11 and the electrode group larger, further improving the support and limiting effect on the electrode group, and is also easy to process and manufacture. In addition, the narrow width of the strip structure is suitable for the narrow area on the outer side of the explosion-proof valve 2 along its width direction.

[0085] In particular, when four support bosses 11 are set, the rectangular enclosure area 114 formed by the line connecting the four support bosses 11 can just surround the explosion-proof valve 2, thereby playing a role in stabilizing the pole group at the explosion-proof valve 2. It can be seen that the minimum number of support bosses 11 can meet the support and limiting requirements of the pole group, which is not only easy to form, but also consumes less material, and can also ensure the strength of the cover plate 1.

[0086] Furthermore, preferably, the explosion-proof valve 2 is positioned at the center of the enclosing area 114 formed by the lines connecting the four supporting protrusions 11. That is, the intersection of the center line of the rectangular enclosing area 114 formed by the four limiting protrusions along the second preset direction b and the center line along the third preset direction c coincides with the intersection of the center line of the explosion-proof valve 2 along the second preset direction b and the center line along the third preset direction c. It can be seen that the four limiting protrusions are evenly arranged around the explosion-proof valve 2, ensuring protection for all areas of the explosion-proof valve 2 and effectively preventing any area from being blocked by the electrode assembly. It should be noted that, not only along the third preset direction c as described above, but also on opposite sides of the explosion-proof valve 2, two supporting protrusions 11 can be provided on each side, or more than two supporting protrusions 11 can be provided on each side, such as three or four supporting protrusions 11, etc., depending on actual needs.

[0087] Furthermore, it should be noted that: along the third preset direction c, the support bosses 11 are not limited to being provided on opposite sides of the explosion-proof valve 2, but may also be provided on only one side. In addition, the support bosses 11 are not limited to being provided on at least one side of the explosion-proof valve 2 along the third preset direction c, but may also be provided on at least one side of the explosion-proof valve 2 along the second preset direction b or at least one side of other directions, or may be provided on both sides of the explosion-proof valve 2 along the second preset direction b and the third preset direction c, or may be provided sequentially at intervals along the entire circumference of the explosion-proof valve 2, depending on the actual needs.

[0088] In one embodiment of this application, preferably, as Figure 2 As shown, the distance between the two support bosses 11 on one side of the explosion-proof valve 2 along the third preset direction c and along the second preset direction b is A3, and the length of the explosion-proof valve mounting hole 113 along the second preset direction b is A0, and 0.35≤A3 / A0≤0.45.

[0089] Based on the structure described above, if A3 / A0 is too small, the two support bosses 11 on each side of the explosion-proof valve 2 will be too close together, which may result in the two support bosses 11 on the same side not being able to completely cover the entire explosion-proof valve 2 along the second preset direction b. This would lead to ineffective protection of the explosion-proof valve 2 as a whole. Moreover, the two support bosses 11 being too close together is also inconvenient for processing and manufacturing. If A3 / A0 is too large, the blank space between the two support bosses 11 along the second preset direction b will be too large, resulting in a lack of effective limit for the electrode assembly in this area. This may lead to the electrode assembly blocking the area corresponding to the explosion-proof valve 2 in this area. In addition, the two support bosses 11 are too dispersed, occupying a lot of space and possibly affecting the installation of other components. Therefore, A3 / A0 should be taken within the optimal range of 0.35-0.45, which can ensure the overall protection of the explosion-proof valve 2 along the second preset direction b, and also avoid being too dispersed, thus affecting the installation of other components.

[0090] Of course, A3 / A0 is not limited to the above optimal range. A3 / A0 can also be set to <0.35 or >0.45, depending on the actual needs.

[0091] In one embodiment of this application, preferably, as Figure 2 As shown, along the second preset direction b, the length of the root of the supporting boss 11 is A4, the length of the cover plate 1 is A1, and 0.3≤2A4 / A1≤0.4.

[0092] Based on the structure described above, a value of 2A4 / A1 that is too small indicates that the length of the supporting boss 11 is too small relative to the length of the cover plate 1, i.e., the length of the pole group, resulting in poor support and limiting effect on the pole group. Conversely, a value of 2A4 / A1 that is too large indicates that the length of the supporting boss 11 is too large relative to the length of the cover plate 1, i.e., the length of the pole group, occupying a large amount of space, potentially affecting the assembly of other components, and increasing material costs. Therefore, 2A4 / A1 should be taken within the optimal range of 0.3-0.4, ensuring both support and limiting effect on the pole group, minimizing space occupation, avoiding impact on the assembly of other components, and reducing material costs. Of course, 2A4 / A1 is not limited to the optimal range mentioned above; it can also be set to 2A4 / A1 < 0.3 or 2A4 / A1 > 0.4, depending on the actual needs.

[0093] In one embodiment of this application, preferably, as Figure 2 and Figure 4 As shown, the distance between the two outer sides of the two supporting bosses 11 on each side of the explosion-proof valve 2 along the second preset direction b and opposite to each other is A2, the length of the explosion-proof valve mounting hole 113 along the second preset direction b is A0, the height of the first step portion 111 along the first preset direction a is H1, the height of the second step portion 112 along the first preset direction a is H2, and 30≤(A2-A0) / [2×(H1+H2)]≤50.

[0094] Based on the structure described above, if the value of (A2-A0) / [2×(H1+H2)] is too small, the support and limiting effect of the support boss 11 on the electrode group will be poor, meaning that it will be unable to achieve overall protection of the explosion-proof valve 2 along the second preset direction b. This could lead to problems such as the explosion-proof valve 2 not opening and the shell tearing. If the value of (A2-A0) / [2×(H1+H2)] is too large, the blank space of the two support bosses 11 along the second preset direction b will be too large. Consequently, this area will lack effective support and limiting for the electrode group, which may lead to the electrode group blocking the area corresponding to the explosion-proof valve 2. Therefore, (A2-A0) / [2×(H1+H2)] should be taken within the above optimal range to ensure the support and limiting effect of the support boss 11 on the electrode group, and to prevent problems such as the explosion-proof valve 2 not opening and the shell tearing.

[0095] Of course, (A2-A0) / [2×(H1+H2)] is not limited to taking values ​​within the above optimal range. It can also be set to (A2-A0) / [2×(H1+H2)]<30 or (A2-A0) / [2×(H1+H2)]>50, depending on the actual needs.

[0096] In one embodiment of this application, preferably, as Figure 2As shown, the width of the cover plate 1 along the third preset direction c is B1, and the distance between the two outer sides of the two corresponding support bosses 11 that are opposite to each other along the third preset direction c is B2, 5mm≤(B1-B2) / 2≤8mm.

[0097] Based on the structure described above, it can be seen that if (B1-B2) / 2 is too small, it indicates that the support boss 11 is too far from the explosion-proof valve 2 along the third preset direction c, and too close to the edge of the cover plate 1. The support boss 11 being too far from the explosion-proof valve 2 results in poor support and limiting effect on the electrode assembly near the explosion-proof valve 2. The electrode assembly near the explosion-proof valve 2 may block the explosion-proof valve 2, thus affecting the exhaust during thermal runaway. Furthermore, being too close to the edge of the cover plate 1 may cause interference with structural components such as the housing, making assembly inconvenient. (B1-B2) / 2 If the value is too large, it indicates that the support boss 11 is too close to the explosion-proof valve 2 along the third preset direction c, which is likely to interfere with the sealing test fixture of the explosion-proof valve 2. Therefore, (B1-B2) / 2 is set within the above-mentioned optimal range of 5mm-8mm. This ensures that the support and limiting effect of the pole group near the explosion-proof valve 2 is good, effectively preventing the pole group near the explosion-proof valve 2 from blocking the explosion-proof valve 2, ensuring normal venting in case of thermal runaway, and avoiding interference with the sealing test fixture of the explosion-proof valve 2 or the shell, thus ensuring assembly efficiency.

[0098] Of course, (B1-B2) / 2 is not limited to the above optimal range. It can also be set to (B1-B2) / 2<5mm or (B1-B2) / 2>8mm, depending on the actual needs.

[0099] In one embodiment of this application, preferably, as Figure 2 As shown, along the third preset direction c, the supporting bosses 11 on opposite sides of the explosion-proof valve 2 are symmetrically arranged about the explosion-proof valve 2, resulting in a more reasonable layout and better support for the electrode assembly. Of course, this is not the only benefit.

[0100] In one embodiment of this application, preferably, as Figures 6 to 9 As shown, the cell cover assembly also includes a lower insulating member 3. Along the first preset direction a, the lower insulating member 3 is installed on the inner side of the cover plate 1 near the electrode group. The lower insulating member 3 forms an exhaust groove 31 with an opening facing the cover plate 1. The exhaust groove 31 is connected to the explosion-proof valve 2. The support boss 11 is located in the exhaust groove 31. The bottom wall of the exhaust groove 31 along the first preset direction a and near the electrode group is formed with a first exhaust area 314. The first exhaust area 314 is correspondingly arranged with the explosion-proof valve 2 along the first preset direction a. The first exhaust area 314 is provided with a plurality of spaced first exhaust holes 311.

[0101] As can be seen from the structure described above, an exhaust groove 31 is provided on the lower insulating member 3, and a first exhaust through hole 311 is provided on the bottom wall of the exhaust groove 31, which helps to exhaust the air during thermal runaway, thereby helping to improve the safety and reliability of the battery cell.

[0102] In one embodiment of this application, preferably, as Figures 6 to 9 As shown, the sum of the projected areas of all the first exhaust holes 311 along the first preset direction a is S1, and the effective opening projected area of ​​the explosion-proof valve 2 is S0. That is to say, the effective opening projected area of ​​the explosion-proof valve 2 along the first preset direction a is S0, and S1 / S0≥0.55.

[0103] Based on the structure described above, a small S1 / S0 indicates insufficient exhaust area of ​​the vent hole, which does not match the effective opening area of ​​the explosion-proof valve, failing to meet the requirement for rapid exhaust during thermal runaway. Therefore, S1 / S0 should be set within the optimal range described above, ensuring that the exhaust area of ​​the vent hole matches the effective opening area of ​​the explosion-proof valve 2, thereby achieving rapid exhaust during thermal runaway. Of course, S1 / S0 is not limited to the optimal range described above; it can also be set to <0.55, depending on the specific needs.

[0104] In one embodiment of this application, preferably, as Figures 6 to 9 As shown, along the second preset direction b, at least one side wall of the exhaust groove 31 is formed with a second exhaust through hole 312 to meet the exhaust demand of at least one side in the length direction.

[0105] Furthermore, preferably, along the second preset direction b, the two opposite side walls of the exhaust groove 31 are each provided with a second exhaust through hole 312. Of course, this is not the only option; the second exhaust through hole 312 may also be provided only on one side wall of the exhaust groove 31 along the second preset direction b, depending on the actual needs.

[0106] In one embodiment of this application, preferably, as Figures 6 to 8 As shown, along the third preset direction c, at least one side wall of the exhaust groove 31 is formed with a third exhaust through hole 313 to meet the exhaust demand of at least one side in the width direction.

[0107] Furthermore, preferably, along the third preset direction c, a third exhaust through hole 313 is formed on each of the opposite side walls of the exhaust groove 31. Of course, it is not limited to this; the third exhaust through hole 313 may also be provided only on one side wall of the exhaust groove 31 along the third preset direction c, depending on the actual needs.

[0108] In one embodiment of this application, preferably, as Figure 7As shown, the length of the lower insulating member 3 along the second preset direction b is L1, the length of the lower insulating member 3 along the third preset direction c is W1, the length of the third exhaust hole 313 along the second preset direction b is L2, the length of the second exhaust hole 312 along the third preset direction c is W2, and 0.4≤(2L2+2W2) / (L1+W1)≤0.7.

[0109] Based on the structure described above, if (2L2+2W2) / (L1+W1) is too small, it indicates that the size of the third exhaust through-hole 313 is too small, reducing the exhaust effect on the side of thermal runaway. If (2L2+2W2) / (L1+W1) is too large, it indicates that the size of the third exhaust through-hole 313 is too large, affecting the strength of the sidewall of the lower insulator 3. Therefore, (2L2+2W2) / (L1+W1) is set within the optimal range of 0.4-0.7 to ensure the size of the third exhaust through-hole 313, guarantee the exhaust effect on the side during thermal runaway, and also guarantee the strength of the sidewall of the lower insulator 3. Of course, (2L2+2W2) / (L1+W1) is not limited to the optimal range mentioned above; it can also be set to (2L2+2W2) / (L1+W1)<0.4 or (2L2+2W2) / (L1+W1)>0.7, depending on the actual needs.

[0110] In one embodiment of this application, preferably, as Figure 7 As shown, multiple exhaust holes are evenly distributed in the first exhaust region 314 along the second preset direction b and the third preset direction c; the length of the third exhaust hole 313 along the second preset direction b is L2, the length of the first exhaust region 314 along the second preset direction b is L3, and 0.5≤L2 / L3≤0.7.

[0111] Based on the structure described above, if L2 / L3 is too small, it indicates that the third exhaust port 313 on the side is too small, affecting the exhaust effect on the side. If L2 / L3 is too large, it indicates that the size of the first exhaust area 314 at the bottom is too small, affecting the exhaust effect at the bottom. Therefore, L2 / L3 should be set within the optimal range of 0.5-0.7 to ensure the exhaust effect at the bottom and on the side, thereby improving the overall exhaust effect. Of course, L2 / L3 is not limited to the optimal range mentioned above; it can also be set to <0.5 or >0.7, depending on the actual needs.

[0112] In one embodiment of this application, preferably, as Figure 7 As shown, the thickness of the opposite side walls of the exhaust groove 31 along the second preset direction b is t1, and t1 = 1.2-2mm, which meets the strength requirements. Of course, t1 is not limited to the above optimal range. It can also be made t1 < 1.2mm or t1 > 2mm, depending on the actual needs.

[0113] In one embodiment of this application, preferably, as Figure 7 As shown, the thickness of the opposite side walls of the exhaust groove 31 along the third preset direction c is t2, and t2 = 1.0-1.5mm, which meets the strength requirements. Of course, t2 is not limited to the above optimal range. It can also be set to t2 < 1.0mm or t2 > 1.5mm, depending on the actual needs.

[0114] In one embodiment of this application, preferably, as Figure 1 and Figure 2 As shown, the first exhaust area 314 is waist-shaped, which matches the shape of the waist-shaped explosion-proof valve 2 to improve the exhaust effect. Of course, it is not limited to this. The first exhaust area 314 can also be other shapes, such as square, circle or other polygons, etc., depending on the actual needs.

[0115] In one embodiment of this application, preferably, as Figure 6 As shown, the overall height of the lower insulating member 3 is H5, and H5 = 2.5-4.5mm, which meets the clamping requirements of the electrode group under normal conditions. Moreover, the venting groove 31 on the lower insulating member 3 with this height can also have sufficient height to accommodate the support boss 11. Of course, it is not limited to this. H5 is not limited to the above-mentioned optimal range. It can also be set to H5 < 2.4mm or H5 > 4.5mm, depending on the actual needs.

[0116] In one embodiment of this application, preferably, as Figures 6 to 9 As shown, the bottom wall of the exhaust groove 31 is formed with an exhaust grille area 315 located on the side of the first exhaust area 314 and spaced apart along the second preset direction b. The exhaust grille area 315 is provided with a transverse rib 3151 and a longitudinal rib 3152. The transverse rib 3151 extends along the second preset direction b, and the longitudinal rib 3152 extends along the third preset direction c.

[0117] As can be seen from the structure described above, the exhaust grille area 315 is provided on the side of the first exhaust area 314, which helps the exhaust of other areas and thus ensures the uniformity of exhaust.

[0118] Furthermore, preferably, exhaust grille areas 315 are provided at intervals on both sides of the first exhaust area 314 along the second preset direction b. Of course, it is not limited to this, and exhaust grille areas 315 may also be provided only on one side of the first exhaust area 314, depending on actual needs.

[0119] Of course, this is not the only option; the exhaust grille area 315 may not be provided, depending on the specific needs.

[0120] In one embodiment of this application, preferably, as Figure 7 As shown, the thickness of the transverse rib 3151 along the third preset direction c is t3, and t3 = 1.5-2.5mm, which meets the strength requirements. Of course, t4 is not limited to the above optimal range. It can also be made t3 < 1.5mm or t3 > 2.5mm, depending on the actual needs.

[0121] In one embodiment of this application, preferably, as Figure 7 As shown, the thickness of the longitudinal rib 3152 along the second preset direction b is t4, and t4 = 1.5-2.5mm, which meets the strength requirements. Of course, t4 is not limited to the above optimal range. It can also be made t4 < 1.5mm or t4 > 2.5mm, depending on the actual needs.

[0122] In one embodiment of this application, preferably, as Figure 7 As shown, along the first preset direction a, the projected area of ​​the outer contour of the exhaust grille area 315 is S3, the sum of the projected areas of the transverse rib 3151 and the longitudinal rib 3152 is S2, and 0.45≤S2 / S3≤0.6.

[0123] Based on the structure described above, a small S2 / S3 ratio indicates that the area occupied by the transverse ribs 3151 and longitudinal ribs 3152 in the exhaust grille region 315 is too small, resulting in weakened strength in this area and poor support and restraint for the pole group under normal conditions. Conversely, a large S2 / S3 ratio indicates that the area occupied by the transverse ribs 3151 and longitudinal ribs 3152 in the exhaust grille region 315 is too large, reducing the hollow exhaust area and worsening the exhaust effect. Therefore, S2 / S3 should be taken within the optimal range of 0.45-0.6 to ensure both effective exhaust during thermal runaway and structural strength in this area, satisfying the support and restraint requirements of the pole group under normal conditions. Of course, S2 / S3 is not limited to the optimal range mentioned above; it can also be set to <0.45 or >0.6, depending on the specific needs.

[0124] It should be noted that the area of ​​the outer contour of the total projection of the exhaust grille area 315 mentioned above refers to the sum of the area of ​​the grille ribs and the area of ​​the hollow area inside the grille.

[0125] In one embodiment of this application, preferably, as Figure 2 As shown, the distance between the root of the support boss 11 near the explosion-proof valve 2 and the explosion-proof valve mounting hole 113 along the direction perpendicular to the first preset direction a is C1, and 4mm≤C1≤7mm.

[0126] Based on the structure described above, it can be seen that if the minimum distance C1 between the root of the support boss 11 near the explosion-proof valve mounting hole 113 and the explosion-proof valve mounting hole 113 is too small, it indicates that the distance between them is too close, which may easily interfere with the sealing test fixture of the explosion-proof valve 2. If the minimum distance C1 between the root of the support boss 11 near the explosion-proof valve mounting hole 113 and the explosion-proof valve mounting hole 113 is too large, it indicates that the distance between them is too far, which results in poor support and limiting effect on the pole group below the explosion-proof valve 2, and also occupies a lot of space. Therefore, C1 should be taken within the above-mentioned optimal range of 4mm-7mm, which will not interfere with the sealing test fixture of the explosion-proof valve 2, but will also ensure the support and limiting effect on the pole group below the explosion-proof valve 2, and will occupy little space. Of course, C1 is not limited to the above-mentioned optimal range; C1 can also be <4mm or >7mm, depending on the actual needs.

[0127] Embodiments of this application also provide a battery cell, including a housing, an electrode assembly, and a battery cell cover assembly as described in any of the above embodiments, wherein the coated electrode assembly is installed inside the housing, and the battery cell cover assembly is installed at the open end of the housing. Therefore, it possesses all the beneficial technical effects of this battery cell cover assembly, which will not be elaborated further here.

[0128] Furthermore, preferably, this battery cell is a blade battery cell, meaning that the aforementioned battery cell cover assembly can be applied to blade batteries to further ensure normal venting in the event of thermal runaway, thus guaranteeing the safety and reliability of the blade battery cell. Of course, the battery cell cover assembly provided in this application can also be applied to other types of battery cells, which will not be detailed here.

[0129] In summary, multiple sets of experiments were conducted to verify the effectiveness of this technical solution: Experimental method: Constant current charging was performed with I = rated charging power P / nominal voltage U until the thermal runaway judgment condition (fire and explosion) was triggered, or the temperature reached 300℃. Then, heating and charging were stopped and the patient was observed for 1 hour.

[0130] Test requirements: It should not ignite or explode after thermal runaway, and should not rupture at a location other than the explosion-proof valve or pressure relief point.

[0131] For details, please refer to section 6.7.4.2.1 of the national standard GB / T 36276.

[0132] Preferably, the initial thermal runaway performance test of the battery cell is carried out according to the following steps: a) The test sample that has completed the initial charging according to national standard 6.2.4.1.1 is placed in the thermal runaway test device; b) Select heating components and temperature sensors and place them on the surface of the test sample. Set the temperature sampling period to 1s. Set the condition for thermal runaway to be that three consecutive temperature rise rate values ​​are ≥3C / s or that fire or explosion occurs. c) Connect the test sample to the charging / discharging device and its voltage data sampling line; d) Charge with a constant current of I=P / U, start heating, and record time, voltage, current, temperature, and rate of temperature rise. Record the experimental phenomena, including expansion, leakage, smoke, fire, explosion, shell rupture and rupture location. e) When the conditions for triggering thermal runaway are met, or the temperature reaches 300°C, or the test time reaches 4 hours, stop charging and heating, observe for 1 hour, and record the time, voltage, temperature, temperature rise rate, and test phenomena, including expansion, leakage, smoke, fire, explosion, shell rupture and rupture location. f) Disconnect the test sample from the charging / discharging device, remove the heating element and data sampling line, and take out the test sample; g) Record the temperature at which thermal runaway occurs as the thermal runaway temperature; h) Repeat steps a) to g) until all test samples are tested.

[0133] The verification results are shown in Table 1 below: Based on the experimental data in the table, it can be seen that when the above design scheme is met, the support and limiting effect of the support boss 11 on the pole group meets the requirements. When the battery cell with the aforementioned structure is set up, the safety test is passed smoothly. Moreover, this battery cell can effectively avoid the problem of the pole group moving and blocking the explosion-proof valve 2, affecting the exhaust effect of the explosion-proof valve 2, thereby greatly improving the safety performance of the battery cell.

[0134] Table 1 Experimental Data

[0135] It should be noted that, unless otherwise specified, all dimensional parameters mentioned in this manual were obtained under the following conditions: Test environment: Measurements were conducted at a temperature of 23℃±2℃ and a relative humidity of 50%±10%. Before measurement, the sample of the battery cell or casing to be measured was placed in this environment and left to stand for at least 2 hours to allow the sample temperature to match the ambient temperature, thereby reducing measurement errors caused by temperature changes. During measurement, the sample was left in a natural state, and no external force was applied to the sample.

[0136] Measurement equipment: Linear dimensions can be measured using an image measuring instrument (image measuring projector) with a measurement accuracy of not less than 0.01 mm; or using vernier calipers with an accuracy of not less than 0.02 mm; for dimensions requiring high precision, a coordinate measuring machine can be used; wall thickness and other dimensions can be measured using a micrometer with an accuracy of not less than 0.001 mm; and protrusions and other structures can be measured using a dial indicator in conjunction with a measuring platform with a measurement accuracy of not less than 0.01 mm.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A cell cover assembly, characterized in that, include: The cover plate and the explosion-proof valve; wherein the cover plate has explosion-proof valve mounting holes extending through both sides along a first preset direction, and the explosion-proof valve is installed in the explosion-proof valve mounting holes; along the first preset direction, a support boss protruding towards the electrode group is formed on the inner side of the cover plate near the electrode group, and along the first preset direction, the support boss is disposed relative to the explosion-proof valve near the electrode group, and the support boss is used to prevent the electrode group from moving towards the explosion-proof valve along the first preset direction and thus blocking the explosion-proof valve.

2. The cell cover assembly according to claim 1, characterized in that, The support boss is a multi-level step arranged along the first preset direction, and along the direction towards the pole group, the area of ​​the projection of the outer contour of each step along the first preset direction gradually decreases, so that the support boss gradually rises towards the pole group.

3. The cell cover assembly according to claim 2, characterized in that, The support boss includes a first step portion and a second step portion; wherein the first step portion and the second step portion are sequentially arranged and connected along the first preset direction, and the second step portion is arranged relative to the first step portion closer to the pole group side.

4. The cell cover assembly according to claim 3, characterized in that, The support boss is formed on the cover plate by stamping; and / or Along the first preset direction, the thickness of the cover plate is T1, and T1 = 2.0-2.5 mm; and / or The height of the first step portion along the first preset direction is H1, the thickness of the cover plate along the first preset direction is T1, and 0.7 ≤ H1 / T1 ≤ 0.85; and / or The wall thickness of the first stepped portion is T2, and T2 = 1.5-2.0 mm; and / or The height of the second step portion along the first preset direction is H2, the wall thickness of the first step portion is T2, and 0.55≤H2 / T2≤0.75; and / or The wall thickness of the second step is T3, and T3 = 1.2-1.6 mm; and / or The height of the first step portion along the first preset direction is H1, and the height of the second step portion along the first preset direction is H2, and 2.5mm ≤ H1 + H2 ≤ 4.0mm; and / or The end faces of the first stepped portion and the second stepped portion near the electrode assembly are both parallel to the end face of the electrode assembly near the explosion-proof valve.

5. The cell cover assembly according to claim 3, characterized in that, Along the third preset direction, the explosion-proof valve is provided with support protrusions on opposite sides, and each of the support protrusions extends along the second preset direction and is strip-shaped. When the support protrusion is a multi-level step, each level of the step is strip-shaped. Along the third preset direction, multiple support protrusions are respectively provided on opposite sides of the explosion-proof valve, and the multiple support protrusions on each side are sequentially spaced along the second preset direction, and the explosion-proof valve is located at the center of the enclosed area formed by the line connecting the multiple support protrusions; along the third preset direction, two support protrusions are respectively provided on opposite sides of the explosion-proof valve, and the enclosed area is rectangular.

6. The cell cover assembly according to claim 5, characterized in that, The distance between the two supporting bosses on one side of the explosion-proof valve along the third preset direction and along the second preset direction is A3, the length of the explosion-proof valve mounting hole along the second preset direction is A0, and 0.35≤A3 / A0≤0.45; and / or Along the second preset direction, the length of the root of the supporting boss is A4, the length of the cover plate is A1, and 0.3≤2A4 / A1≤0.4; and / or The distance between the two outer sides of the two supporting bosses on each side of the explosion-proof valve, which are opposite to each other along the second preset direction, is A2; the length of the explosion-proof valve mounting hole along the second preset direction is A0; the height of the first step portion along the first preset direction is H1; the height of the second step portion along the first preset direction is H2; and 30≤(A2-A0) / [2×]≤50; and / or The width of the cover plate along the third preset direction is B1, and the distance between the two opposite outer sides of the two corresponding supporting bosses along the third preset direction is B2, and 5mm≤(B1-B2) / 2≤8mm; and / or Along the third preset direction, the supporting bosses on opposite sides of the explosion-proof valve are symmetrically arranged with respect to the explosion-proof valve.

7. The cell cover assembly according to claim 1, characterized in that, The cell cover assembly further includes a lower insulating member, and along the first preset direction, the lower insulating member is installed on the inner side of the cover near the electrode group, and the lower insulating member forms an exhaust groove with an opening facing the cover side, and the exhaust groove is connected to the explosion-proof valve, and the support boss is located in the exhaust groove; The bottom wall of the exhaust groove along the first preset direction and close to the electrode group side has a first exhaust area, and the first exhaust area is correspondingly arranged with the explosion-proof valve along the first preset direction, and the first exhaust area is provided with a plurality of spaced first exhaust holes.

8. The cell cover assembly according to claim 7, characterized in that, The sum of the areas of the projections of all the first exhaust orifices along the first preset direction is S1, the effective opening area of ​​the explosion-proof valve is S0, and S1 / S0 ≥ 0.55; and / or Along the second preset direction, at least one side wall of the exhaust groove is formed with a second exhaust through hole; Along a third predetermined direction, at least one side wall of the exhaust groove is formed with a third exhaust through hole; The length of the lower insulating member along the second preset direction is L1, the length of the lower insulating member along the third preset direction is W1, the length of the third vent hole along the second preset direction is L2, and the length of the second vent hole along the third preset direction is W2, and 0.4≤(2L2+2W2) / (L1+W1)≤0.7; and / or Multiple exhaust holes are evenly distributed within the first exhaust area along the second and third preset directions; The length of the third exhaust port along the second preset direction is L2, and the length of the first exhaust region along the second preset direction is L3, and 0.5 ≤ L2 / L3 ≤ 0.7; and / or The thickness of the opposite side walls of the exhaust groove along the second preset direction is t1, and t1 = 1.2-2 mm; and / or The thickness of each of the two opposing side walls of the exhaust groove along the third preset direction is t2, and t2 = 1.0-1.5 mm; and / or The overall height of the lower insulating component is H5, and H5 = 2.5-4.5 mm; and / or The explosion-proof valve and the first exhaust area are both oblong in shape and their shapes are compatible; and / or The bottom wall of the exhaust groove is formed with an exhaust grille area located on the side of the first exhaust area and spaced apart along the second preset direction, and the exhaust grille area is provided with transverse ribs and longitudinal ribs, and the transverse ribs extend along the second preset direction and the longitudinal ribs extend along the third preset direction. The thickness of the transverse rib along the third preset direction is t3, and t3 = 1.5-2.5 mm; The thickness of the longitudinal rib along the second preset direction is t4, and t4 = 1.5-2.5 mm; Along the first preset direction, the projected area of ​​the outer contour of the exhaust grille area is S3, the sum of the projected areas of the transverse ribs and the longitudinal ribs is S2, and 0.45≤S2 / S3≤0.

6.

9. The cell cover assembly according to any one of claims 1 to 8, characterized in that, The distance between the root of the support boss located near the explosion-proof valve and the mounting hole of the explosion-proof valve along a direction perpendicular to the first preset direction is C1, and 4mm≤C1≤7mm; and / or The explosion-proof valve is located at the center of the cover plate, and the length direction of the explosion-proof valve is the same as the length direction of the cover plate, and the width direction of the explosion-proof valve is the same as the width direction of the cover plate. and / or The first preset direction is the thickness direction of the cover plate, the second preset direction is the length direction of the cover plate, and the third preset direction is the width direction of the cover plate; and / or The support boss is positioned close to the explosion-proof valve mounting hole; and / or The supporting boss is a rectangular structure, and when the supporting boss is a rectangular structure, each step is also rectangular.

10. A battery cell, characterized in that, It includes a housing, an electrode assembly, and a cell cover assembly as described in any one of claims 1 to 9; wherein the coated electrode assembly is installed inside the housing, and the cell cover assembly is installed at the open end of the housing; the cell is a blade cell.

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