Pole and cell cover assembly

Abstract

The application relates to the technical field of batteries, in particular to a pole and a battery cell cover plate assembly, the pole comprising a body and a bottom plate; wherein the body comprises a column body, an upper boss and a lower boss which are sequentially connected along a first preset direction, the bottom plate is formed with a matching through hole arranged along the first preset direction, the lower boss is installed in the matching through hole, the lower boss and the sidewall of the matching through hole are connected through welding, and the upper boss is arranged on the outer side surface of the bottom plate close to the body. It can be seen that the pole is designed as a split structure, namely the body and the bottom plate, so that the two parts of the structure can be separately manufactured, thereby helping to improve the utilization rate of materials and further reducing the production cost.

Description

Technical Field

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

[0002] Lithium-ion batteries are widely used in various fields such as transportation power supplies, power storage, new energy storage power supplies, and 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 lithium-ion batteries is the energy storage cell, which generally has a large capacity and adopts a bipolar structure. To reduce production costs and internal resistance, a direct tab welding scheme is generally used, that is, the tabs are directly laser-welded to the base plate of the terminal post. However, the required welding area is relatively large (due to high current requirements, the tab welding area is large), resulting in a larger cross-sectional area of ​​the base plate of the terminal post relative to the upper structure, that is, a larger length and width of the base plate, while the diameter of the structure above the base plate is smaller. If the commonly used one-piece structure is used for stamping manufacturing, the initial raw material size must be selected according to the size of the base plate of the terminal post, which leads to lower material utilization and increased production costs. Summary of the Invention

[0003] The purpose of this application is to provide an electrode post and cell cover assembly, which to some extent solves the technical problem in the prior art where the cross-sectional area of ​​the electrode post base plate is too large relative to the upper structure. If the commonly used one-piece structure is used for stamping manufacturing, the initial raw material size must be selected according to the size of the electrode post base plate, which leads to low material utilization and increased production costs.

[0004] This application provides a pole post, including: a body and a base plate; wherein, the body includes a column, an upper boss and a lower boss connected sequentially along a first preset direction, the base plate is formed with a mating through hole arranged along the first preset direction, and the lower boss is installed in the mating through hole, and the lower boss is connected to the side wall of the mating through hole by welding, and the upper boss is disposed against the outer surface of the base plate near the body.

[0005] In the above technical solution, further, along the first preset direction, the thickness of the upper boss is T1, and T1 = 0.9-1.1 mm.

[0006] In any of the above technical solutions, further, along the first preset direction, the thickness of the lower boss is T2, and T2 = 0.5-0.8 mm.

[0007] In any of the above technical solutions, further, along the first preset direction, the thickness of the base plate is T3, and T3 = 0.7-1.1 mm.

[0008] In any of the above technical solutions, the thickness of the lower boss is T2, the thickness of the base plate is T3, and t1=T3-T2=0.2-0.3mm.

[0009] In any of the above technical solutions, the lower boss is further described as having a polygonal structure, and the mating through hole is adapted to the shape of the lower boss.

[0010] In any of the above technical solutions, the outer side of the column is used to fit a sealing ring for the battery cell, and the sealing ring is disposed against the surface of the upper boss away from the bottom plate; the sealing ring includes a first ring portion and a second ring portion connected sequentially along the first preset direction, and the outer diameter of the second ring portion is larger than the outer diameter of the first ring portion; the second ring portion is disposed near the bottom plate side.

[0011] In any of the above technical solutions, the diameter of the part of the column that mates with the sealing ring is D0, the outer diameter of the second ring is D1, and 2mm≤(D1-D0) / 2≤3mm.

[0012] In any of the above technical solutions, the outer diameter of the second ring is D1, the upper boss is a frustum, and the outer diameter of the upper boss is D2, and 1mm≤(D2-D1) / 2≤2mm.

[0013] In any of the above technical solutions, the diameter of the part of the column that mates with the sealing ring is D0, the maximum outer contour dimension of the lower boss along the third preset direction is D3, and 2mm≤(D0-D3) / 2≤3mm.

[0014] In any of the above technical solutions, the column further includes a first column, a second column, and a third column connected sequentially along the first preset direction; wherein, the first column is connected to the upper boss, and the first column is used to fit the sealing ring; the first column, the second column, and the third column are all cylindrical structures, and the diameters of the first column and the third column are both larger than the diameter of the second column.

[0015] In any of the above technical solutions, the mating through hole further includes a first hole portion and a second hole portion arranged sequentially along the first preset direction, and the first hole portion is arranged close to the body, and the projection of the first hole portion along the first preset direction completely falls into the projection of the second hole portion along the first preset direction, and the outer edges of the two are spaced apart along a direction perpendicular to the first preset direction; the lower boss is installed in the first hole portion, and the lower boss is connected to the side wall of the first hole portion by welding, forming an annular first weld mark.

[0016] In any of the above technical solutions, the depth of the first solder mark along the first preset direction is t2, and t2 = 0.4-0.8 mm.

[0017] In any of the above technical solutions, further, along the third preset direction, the maximum dimension of the outer contour of the first solder mark is L1, the length of the base plate is L2, and 0.15≤L1 / L2≤0.20.

[0018] In any of the above technical solutions, the base plate is further used to weld the electrode tabs of the electrode group of the battery cell to form a second solder mark, and along a third preset direction, the distance between the first solder mark and the second solder mark is A, and 5mm≤A≤8mm.

[0019] In any of the above technical solutions, the sidewall of the first solder mark near the second solder mark is arranged parallel to the second solder mark.

[0020] This application also provides a battery cell cover assembly, including a cover plate, a lower plastic core, and a terminal post as described in any of the above-mentioned technical solutions. The lower plastic core is installed on the inner side of the cover plate near the electrode assembly of the battery cell. The cover plate has a mounting hole, and the body of the terminal post is installed within the mounting hole. The lower plastic core has a clearance through-hole, and one end of the body extends through the clearance through-hole to the inner side of the lower plastic core near the electrode assembly, and is welded to the base plate of the terminal post located inside the lower plastic core. Therefore, it possesses all the beneficial technical effects of this terminal post, which will not be elaborated further here.

[0021] Compared with the prior art, the beneficial effects of this application are as follows: In this application, the electrode post is designed as a split structure, namely, a main body and a base plate. This allows the two parts to be manufactured separately, thereby improving material utilization. Furthermore, by setting an upper boss and a lower boss on the main body and correspondingly setting a mating through hole on the base plate, the lower boss is installed in the mating through hole, and the upper boss is set against the outer surface of the base plate near the main body. This completes the initial assembly of the main body and the base plate, which are then connected by welding to form the final electrode post, meeting the usage requirements of the electrode post. Moreover, the material utilization rate is high, further reducing production costs. Attached Figure Description

[0022] 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.

[0023] Figure 1 This is a schematic diagram of the structure of the cell cover assembly provided in the embodiments of this application; Figure 2 This is a schematic diagram of the structure of the body provided in the embodiments of this application; Figure 3 Another structural schematic diagram of the ontology provided in the embodiments of this application; Figure 4 Another structural schematic diagram of the ontology provided in the embodiments of this application; Figure 5 for Figure 4 A sectional view along section AA; Figure 6 This is a schematic diagram of the structure of the base plate provided in the embodiments of this application; Figure 7 An assembly drawing of the body and base plate provided for embodiments of this application; Figure 8 Another assembly drawing of the body and base plate provided in the embodiments of this application; Figure 9 Another assembly drawing of the body and base plate provided in an embodiment of this application; Figure 10 Another assembly drawing of the body and base plate provided in an embodiment of this application; Figure 11 for Figure 10 A sectional view along section BB; Figure 12 Another assembly drawing of the body and base plate provided in an embodiment of this application; Figure 13 An assembly drawing of the pole post and sealing ring provided in an embodiment of this application; Figure 14 Another assembly drawing of the pole post and sealing ring provided in the embodiments of this application; Figure 15 for Figure 14 A sectional view along section CC; Figure 16 A schematic diagram of the welding between the electrode lug and the base plate of the electrode post provided in the embodiments of this application; Figure 17 for Figure 16 A partially enlarged structural diagram; Figure 18Another welding schematic diagram of the electrode lug and the base plate of the electrode post provided in the embodiments of this application; Figure 19 for Figure 18 A partially enlarged structural diagram; Figure 20 Another welding schematic diagram of the electrode lug and the base plate of the electrode post provided in the embodiments of this application; Figure 21 for Figure 20 A partially enlarged structural diagram.

[0024] Figure label: 1-Pole post, 11-Body, 111-Pole body, 1111-First pole body, 1112-Second pole body, 1113-Third pole body, 1114-Assembly groove, 112-Upper boss, 113-Lower boss, 12-Base plate, 121-Matching through hole, 1211-First hole, 1212-Second hole, 2-Sealing ring, 21-First ring, 22-Second ring, 3-Cover plate, 4-Lower plastic, 5-First solder mark, 6-Pole group, 61-Pole tab, 7-Second solder mark, 10-Cell cover plate assembly, a-First preset direction, c-Third preset direction. Detailed Implementation

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] The following reference Figures 1 to 21 This application describes the electrode post and cell cover plate assembly according to some embodiments.

[0031] See Figures 1 to 21 As shown, an embodiment of this application provides a pole post 1, including: a body 11 and a base plate 12; wherein, the body 11 includes a column 111, an upper boss 112 and a lower boss 113 connected sequentially along a first preset direction a, the base plate 12 is formed with a mating through hole 121 provided along the first preset direction a, and the lower boss 113 is installed in the mating through hole 121, and the lower boss 113 is connected to the side wall of the mating through hole 121 by welding, and the upper boss 112 is disposed against the outer surface of the base plate 12 near the body 11.

[0032] As can be seen from the structure described above, the pole post 1 is designed as a split structure, namely, the main body 11 and the base plate 12. In this way, the two parts can be manufactured separately, which helps to improve the material utilization rate. By setting an upper boss 112 and a lower boss 113 on the main body 11, and correspondingly setting a mating through hole 121 on the base plate 12, the lower boss 113 is installed in the mating through hole 121, and the upper boss 112 is set against the outer surface of the base plate 12 near the main body 11, the initial assembly of the main body 11 and the base plate 12 is completed. They are then connected by welding to form the final pole post 1, which meets the usage requirements of the pole post 1. Moreover, the material utilization rate is high, further reducing the production cost.

[0033] Furthermore, preferably, the first preset direction a is the height direction of the pole post 1, and the height direction of the pole post 1 is the same as the thickness direction of the cover plate 3. Of course, it is not limited to this.

[0034] In one embodiment of this application, preferably, as Figure 5As shown, along the first preset direction a, the thickness of the upper boss 112 is T1, and T1 = 0.9-1.1mm, such as 0.9mm, 0.92mm, 0.95mm, 0.97mm, or 1.0mm, etc., to meet assembly requirements and ensure the stability and robustness of the structure after assembly. Of course, T1 is not limited to the above optimal range; it can also be set to <0.9mm or >1.1mm, depending on actual needs.

[0035] In one embodiment of this application, preferably, as Figure 5 As shown, along the first preset direction a, the thickness of the lower boss 113 is T2, and T2 = 0.5-0.8mm, such as 0.5mm, 0.6mm, 0.65mm, 0.7mm, or 0.8mm, etc., to meet assembly requirements and ensure the stability and robustness of the structure after assembly. Of course, T2 is not limited to the above optimal range; it can also be set to <0.5mm or >0.8mm, depending on actual needs.

[0036] In one embodiment of this application, preferably, as Figure 11 As shown, along the first preset direction a, the thickness of the base plate 12 is T3, and T3 = 0.7-1.1mm, such as 0.7mm, 0.8mm, 0.9mm, 1.0mm, or 1.1mm, etc., to meet the strength and welding requirements. Of course, T3 is not limited to the above optimal range; it can also be set to <0.7mm or >1.1mm, depending on the actual needs.

[0037] In one embodiment of this application, preferably, as Figure 5 and Figure 11 As shown, along the first preset direction a, the thickness of the lower boss 113 is T2, the thickness of the base plate 12 is T3, and t1=T3-T2=0.2-0.3mm, for example 0.2mm, 0.21mm, 0.23mm, 0.25mm, 0.26mm, 0.28mm or 0.3mm, etc.

[0038] As described above, if T3-T2 is too small, the solder mark will extend beyond the lower surface of the base plate 12 near the electrode group 6, affecting assembly. If T3-T2 is too large, it will be inconvenient for welding and will occupy a large space. Therefore, setting T3-T2 within the above-mentioned optimal range can effectively prevent the solder mark from extending beyond the lower surface of the base plate 12, avoiding interference, while also facilitating welding and occupying less space. Of course, T3-T2 is not limited to the above-mentioned optimal range; it can also be set to T3-T2 < 0.2 mm or T3-T2 > 0.3 mm, depending on the actual needs.

[0039] In one embodiment of this application, preferably, as Figure 2 and Figure 12 As shown, the lower boss 113 has a polygonal structure, and the through hole 121 is adapted to the shape of the lower boss 113.

[0040] As can be seen from the structure described above, the lower boss 113 and the mating through hole 121 adopt a multi-deformation structure, which serves as a limit and prevents relative rotation.

[0041] Furthermore, preferably, both the lower boss 113 and the mating through hole 121 are hexagonal structures. Of course, they are not limited to this. They can also adopt other polygonal structures such as quadrilaterals or pentagons, or non-polygonal structures such as circles, depending on the actual needs.

[0042] In one embodiment of this application, preferably, as Figure 2 and Figure 5 As shown, the column 111 includes a first column 1111, a second column 1112, and a third column 1113 connected sequentially along a first preset direction a; wherein, the first column 1111 is connected to the upper boss 112; the first column 1111, the second column 1112, and the third column 1113 are all cylindrical structures, and the diameters of the first column 1111 and the third column 1113 are both larger than the diameter of the second column 1112.

[0043] As described above, since the diameters of the first column 1111 and the third column 1113 are both larger than the diameter of the second column 1112, the three columns form an annular assembly groove 1114. This assembly groove 1114 can be used with a rivet block or an upper plastic piece to improve the stability and firmness of the assembly. Of course, this is not the only option; the columns 111 can also be of equal diameter, depending on the specific needs.

[0044] In one embodiment of this application, preferably, as Figures 13 to 15 As shown, the outer side of the column 111 is used to fit the sealing ring 2 of the battery cell, and the sealing ring 2 is disposed against the surface of the upper boss 112 away from the bottom plate 12; the sealing ring 2 includes a first ring portion 21 and a second ring portion 22 connected sequentially along a first preset direction a, and the outer diameter of the second ring portion 22 is larger than the outer diameter of the first ring portion 21 to form a convex structure; the second ring portion 22 is disposed near the bottom plate 12.

[0045] As can be seen from the structure described above, a convex sealing ring is provided on the outside of the column 111, which can meet the sealing requirements.

[0046] In one embodiment of this application, preferably, as Figure 15As shown, the diameter of the part of the column 111 that mates with the sealing ring 2, i.e., the diameter of the first column 1111, is D0, and the outer diameter of the second ring 22 is D1, and 2mm≤(D1-D0) / 2≤3mm, such as 2mm, 2.2mm, 2.5mm, 2.7mm or 3mm, etc.

[0047] As can be seen from the structure described above, ensuring that the sealing ring 2 has sufficient wall thickness is crucial to guaranteeing sufficient compression and thus ensuring sealing performance after compression. Of course, (D1-D0) / 2 is not limited to the optimal range described above; it can also be set to (D1-D0) / 2 < 2mm or (D1-D0) / 2 > 3mm, depending on the specific needs.

[0048] In one embodiment of this application, preferably, as Figure 15 As shown, the outer diameter of the second ring 22 is D1, the upper boss 112 is a frustum of a cone, and the outer diameter of the upper boss 112 is D2. Furthermore, 1mm ≤ (D2-D1) / 2 ≤ 2mm, for example, 1mm, 1.3mm, 1.6mm, 1.9mm, or 2mm, etc., so that the upper boss 112 has sufficient area to support the second ring 22, avoiding gaps below the second ring 22 and meeting assembly and sealing requirements. Of course, (D2-D1) / 2 is not limited to the above optimal range; it can also be set to (D2-D1) / 2 < 1mm or (D2-D1) / 2 > 2mm, depending on actual needs.

[0049] In one embodiment of this application, preferably, as Figure 15 As shown, the diameter of the part of the column 111 that mates with the sealing ring 2, i.e. the first column 1111, is D0, and the maximum outer contour dimension of the lower boss 113 along the third preset direction c is D3, and 2mm≤(D0-D3) / 2≤3mm, for example, 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm or 3mm, etc.

[0050] Based on the structure described above, it can be seen that if the value of (D0-D3) / 2 is too small, the distance between the weld and the sealing ring 2 will be too small, leading to thermal deformation of part of the sealing ring 2 after welding, affecting the sealing effect. If the value of (D0-D3) / 2 is too large, the size of the lower boss 113 at the bottom will be too small, resulting in a small welding area, which in turn leads to an unstable and unreliable structure after welding. Therefore, setting (D0-D3) / 2 within the above-mentioned optimal range can effectively avoid the problem of thermal deformation of the sealing ring 2 and ensure the stability and reliability of the welded structure. Of course, (D0-D3) / 2 is not limited to the above-mentioned optimal range; it can also be set to (D0-D3) / 2 < 2mm or (D0-D3) / 2 > 3mm, depending on the actual needs.

[0051] Furthermore, preferably, the third preset direction c is the length direction of the base plate 12, and the length direction of the base plate 12 can be the same as the width direction of the cover plate 3. Of course, it is not limited to this; the third preset direction c can be the width direction of the base plate 12, etc. In addition, the third preset direction c can also be the same as the length direction of the cover plate 3, depending on the actual needs.

[0052] In one embodiment of this application, preferably, as Figure 6 and Figure 15 As shown, the through hole 121 includes a first hole portion 1211 and a second hole portion 1212 arranged sequentially along a first preset direction a. The first hole portion 1211 is located close to the body 11, and the projection of the first hole portion 1211 along the first preset direction a completely falls into the projection of the second hole portion 1212 along the first preset direction a. The outer edges of the two are spaced apart along a direction perpendicular to the first preset direction a. The lower boss 113 is installed in the first hole portion 1211, and the lower boss 113 is connected to the side wall of the first hole portion 1211 by welding, forming an annular first weld mark 5.

[0053] As can be seen from the structure described above, the first hole 1211 is used to mate with the lower boss 113, and the second hole 1212 facilitates welding and also allows the solder mark to be lower than the lower surface of the base plate 12. Of course, it is not limited to this; the mating through hole 121 can also be a hole with the same upper and lower dimensions that runs straight along the first preset direction a, depending on the actual needs.

[0054] In one embodiment of this application, preferably, as Figure 11 As shown, the depth of the first solder mark 5 along the first preset direction a is t2, and t2 = 0.4-0.8 mm, for example, 0.4 mm, 0.5 mm, 0.55 mm, 0.6 mm or 0.8 mm, etc.

[0055] Based on the structure described above, it is clear that if the depth t2 of the weld is too small, the strength after welding will be insufficient; if the weld depth t2 is too large, it will easily cause thermal deformation. Therefore, setting t2 within the above-mentioned optimal range can effectively ensure the strength after welding and prevent thermal deformation. Of course, t2 is not limited to the above-mentioned optimal range; it can also be set to t2 < 0.4 mm or t2 > 0.8 mm, depending on the actual needs.

[0056] In one embodiment of this application, preferably, as Figure 12 As shown, along the third preset direction c, the maximum dimension of the outer contour of the first solder mark 5 is L1, the length of the base plate 12 is L2, and 0.15≤L1 / L2≤0.20, for example 0.15, 0.17, 0.18, 0.19 or 0.2, etc.

[0057] Based on the structure described above, it can be seen that if the value of L1 / L2 is too small, that is, the ratio of the span of the first weld mark 5 to the length of the base plate 12 is too small, the strength of the weld between the lower boss 113 and the base plate 12 is insufficient. If the value of L1 / L2 is too large, that is, the ratio of the span of the first weld mark 5 to the length of the base plate 12 is too large, the welding heat is high, and it is easy to cause thermal deformation. Therefore, setting L1 / L2 within the above-mentioned optimal range can effectively ensure the strength after welding and prevent thermal deformation. Of course, L1 / L2 is not limited to the above-mentioned optimal range; it can also be set to L1 / L2 < 0.15 or L1 / L2 > 0.20, depending on the actual needs.

[0058] In one embodiment of this application, preferably, as Figure 19 As shown, the base plate 12 is used to weld to the tabs 61 of the electrode group 6 of the battery cell, and to form a second solder mark 7. Along the third preset direction c, the distance between the first solder mark 5 and the second solder mark 7 is A, and 5mm≤A≤8mm, such as 5mm, 5.5mm, 6.0mm, 6.2mm, 6.5mm, 6.8mm, 7.0mm, 7.3mm, 7.5mm, 7.9mm or 8mm, etc.

[0059] As described above, if the two solder joints are too close together, the tab 61 will deform severely and be damaged. If the two solder joints are too far apart, the space utilization will be reduced. Therefore, the distance A between the two solder joints should be set within the optimal range described above. This will effectively prevent damage to the tab 61 and help improve space utilization. Of course, A is not limited to the optimal range described above; it can also be set to A < 5mm or A > 8mm, depending on the actual needs.

[0060] In one embodiment of this application, preferably, as Figure 17 , Figure 19 and Figure 21 As shown, the sidewall of the first weld mark 5 closest to the second weld mark 7 is arranged parallel to the second weld mark 7, which effectively ensures that the distance between them meets the usage requirements, and the layout is reasonable, helping to improve space utilization. Of course, it is not limited to this; the sidewall of the first weld mark 5 closest to the second weld mark 7 can also be arranged non-parallel to the second weld mark 7, depending on the actual needs.

[0061] 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.

[0062] 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.

[0063] For details, please refer to section 6.7.4.2.1 of the national standard GB / T 36276.

[0064] 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 ≥3℃ / 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.

[0065] 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 yield rate of the cell cover assembly 10 is normal, with no issues such as deformation of the base plate 12 of the electrode post 1 or welding affecting the sealing effect of the sealing ring 2, and the material utilization rate of the electrode post 1 is significantly improved. It should be noted that the electrode post 1 and sealing ring 2 provided in this application belong to the cell cover assembly 10, therefore, the yield rate of the cell cover assembly 10 is used as the evaluation parameter here.

[0066] 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.

[0067] 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.

[0068] Table 1 Experimental Data

[0069] It should be noted that the units of the parameters in the table are as described above and will not be repeated here.

[0070] like Figure 1 As shown, an embodiment of this application also provides a cell cover assembly 10, including a cover plate 3, a lower plastic 4, and a terminal post 1 from any of the above embodiments. The lower plastic 4 is installed on the inner side of the cover plate 3 near the electrode group 6 of the cell. The cover plate 3 has a mounting hole, the body 11 of the terminal post 1 is installed in the mounting hole, and the base plate 12 is installed on the inner side of the insulating member near the electrode group 6. The lower plastic 4 has a clearance through hole, and one end of the body 11 extends through the clearance through hole to the inner side of the lower plastic 4 near the electrode group 6, and is connected to the base plate 12 of the terminal post 1 located inside the lower plastic 4 by welding. Therefore, it possesses all the beneficial technical effects of the terminal post 1, which will not be elaborated further here.

[0071] It should be noted that the aforementioned sealing ring 2 is also part of the structure in the cell cover assembly 10, and will not be described in detail here.

[0072] In addition, it should be noted that the cell cover assembly may include one terminal post, which may adopt the structure of the aforementioned terminal post 1. The cell cover assembly may also include two terminals, and when there are two terminals, the two terminals are the positive terminal post and the negative terminal post, wherein both the positive terminal post and the negative terminal post may adopt the structure of the aforementioned terminal post 1. Of course, it is not limited to this. Only the positive terminal post or only the negative terminal post may adopt the structure of the aforementioned terminal post 1, depending on the actual needs.

[0073] 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. An electrode post, characterized in that, include: The body and the base plate; wherein the body includes a column, an upper boss and a lower boss connected sequentially along a first preset direction, the base plate is formed with a mating through hole arranged along the first preset direction, and the lower boss is installed in the mating through hole, and the lower boss is connected to the side wall of the mating through hole by welding, and the upper boss is disposed against the outer surface of the base plate near the body.

2. The pole post according to claim 1, characterized in that, Along the first preset direction, the thickness of the upper boss is T1, and T1 = 0.9-1.1 mm; and / or Along the first preset direction, the thickness of the lower boss is T2, and T2 = 0.5-0.8 mm; and / or Along the first preset direction, the thickness of the base plate is T3, and T3 = 0.7-1.1 mm.

3. The pole piece according to claim 1, characterized in that, Along the first preset direction, the thickness of the lower boss is T2, the thickness of the base plate is T3, and t1 = T3 - T2 = 0.2 - 0.3 mm; and / or The lower boss has a polygonal structure, and the mating through hole is adapted to the shape of the lower boss.

4. The pole post according to claim 1, characterized in that, The outer surface of the column is used to fit a sealing ring for the battery cell, and the sealing ring is disposed against the surface of the upper boss away from the bottom plate; the sealing ring includes a first ring portion and a second ring portion connected sequentially along the first preset direction, and the outer diameter of the second ring portion is larger than the outer diameter of the first ring portion; the second ring portion is disposed near the bottom plate side.

5. The electrode post according to claim 4, characterized in that, The diameter of the portion of the column that mates with the sealing ring is D0, the outer diameter of the second ring is D1, and 2mm ≤ (D1-D0) / 2 ≤ 3mm; and / or The outer diameter of the second ring is D1, the upper boss is a frustum, and the outer diameter of the upper boss is D2, and 1mm ≤ (D2-D1) / 2 ≤ 2mm; and / or The diameter of the portion of the column that mates with the sealing ring is D0, the maximum outer contour dimension of the lower boss along the third preset direction is D3, and 2mm≤(D0-D3) / 2≤3mm; and / or The column includes a first column, a second column, and a third column connected sequentially along the first preset direction; wherein, the first column is connected to the upper boss, and the first column is used to fit the sealing ring; the first column, the second column, and the third column are all cylindrical structures, and the diameters of the first column and the third column are both larger than the diameter of the second column.

6. The pole post according to any one of claims 1 to 5, characterized in that, The mating through hole includes a first hole portion and a second hole portion arranged sequentially along the first preset direction. The first hole portion is located close to the body, and the projection of the first hole portion along the first preset direction completely falls into the projection of the second hole portion along the first preset direction. The outer edges of the two are spaced apart along a direction perpendicular to the first preset direction. The lower boss is installed in the first hole portion, and the lower boss is connected to the side wall of the first hole portion by welding, forming a ring-shaped first weld mark.

7. The pole post according to claim 6, characterized in that, The depth of the first solder mark along the first preset direction is t2, and t2 = 0.4-0.8 mm; and / or Along the third preset direction, the maximum dimension of the outer contour of the first solder mark is L1, the length of the base plate is L2, and 0.15≤L1 / L2≤0.

20.

8. The electrode post according to claim 6, characterized in that, The base plate is used to weld to the tabs (61) of the electrode group of the battery cell and form a second solder mark. The distance between the first solder mark and the second solder mark is A along a third preset direction, and 5mm≤A≤8mm.

9. The pole post according to claim 8, characterized in that, The sidewall of the first solder mark near the second solder mark is arranged parallel to the second solder mark.

10. A cell cover assembly, characterized in that, The device includes a cover plate, a lower plastic core, and an electrode post according to any one of claims 1 to 9; wherein the lower plastic core is installed on the inner side of the electrode assembly near the battery cell of the cover plate; the cover plate has a mounting hole, and the body of the electrode post is installed in the mounting hole; the lower plastic core has a clearance through hole, and one end of the body extends through the clearance through hole to the inner side of the lower plastic core near the electrode assembly, and is connected to the base plate of the electrode post located inside the lower plastic core by welding.

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