Output terminal base and battery module

Abstract

This application provides an output electrode base and a battery module, solving the problem in the prior art where the expansion of the battery cell assembly generates additional mechanical stress on the output electrode connector, affecting the safety and service life of the battery module. The output electrode base is used to connect the output electrode connector in the battery module. The battery module includes a mounting assembly for mounting the battery cell assembly, and the mounting assembly has mounting holes. The output electrode base is inserted into the mounting holes. The output electrode base includes a base body and a mounting post. The base body is used to connect the output electrode connector; the mounting post is connected to one side of the base body and is used to insert into the mounting hole; the mounting post has a first sidewall facing the battery cell assembly, and the mounting hole has a first inner wall close to the battery cell assembly, with a first gap between the first sidewall and the first inner wall.

Description

Technical Field

[0001] This application relates to the field of battery module technology, specifically to an output electrode base and a battery module. Background Technology

[0002] After the battery module is assembled, the output terminal connectors, such as copper busbars, are connected to the battery busbars using bolts, thereby outputting the collected current to provide power. To ensure safe current output at the connection point between the output terminal copper busbars and the battery busbars, an output terminal base is usually installed at this connection point.

[0003] The output terminal base is typically rigidly fixed to the crossbeam or end plate of the battery module housing using bolts. During charging and discharging, when the battery expands due to temperature changes or electrochemical reactions, the entire cell within the battery module deforms along the direction of expansion. This deformation is directly transmitted to the output terminal base through the rigid connection structure, and then to the cell terminals and output busbar connected to the output terminal base. This results in significant mechanical tensile forces on the solder joints between the cell terminals and the output busbar. If these forces exceed the strength threshold of the cell terminals or solder joints, it may lead to poor soldering, cracking, or even electrical connection failure, severely impacting the safety and lifespan of the battery module. Summary of the Invention

[0004] In view of this, the embodiments of this application aim to provide an output electrode base and a battery module to improve the problem in the prior art where the expansion of the battery cell pack causes additional mechanical stress on the output electrode connector, affecting the safety and service life of the battery module.

[0005] In a first aspect, embodiments of this application provide an output electrode base for connecting an output electrode connector in a battery module. The battery module includes a mounting assembly for mounting a battery cell assembly. The mounting assembly has mounting holes, and at least a portion of the output electrode base is inserted into the mounting holes. The output electrode base includes:

[0006] The base body is used to connect the output electrode connector;

[0007] Mounting post, connected to one side of the base body and used to be inserted into the mounting hole;

[0008] The mounting post has a first sidewall facing the battery cell assembly, the mounting hole has a first inner wall close to the battery cell assembly, and a first gap exists between the first sidewall and the first inner wall.

[0009] In some embodiments, the width c of the first gap along the first direction satisfies:

[0010] c = m + n;

[0011] Wherein, m refers to the minimum moving distance required for the mounting assembly, provided that the tensile force on the output electrode connector does not exceed the threshold, and the minimum moving distance refers to the minimum moving distance of the output electrode connector along the first direction, and n refers to the tolerance allowance for the assembly of the mounting post and the mounting hole.

[0012] In some embodiments, along the second direction, the mounting hole has two opposing second inner walls, and the mounting post has two opposing second side walls, each of the second side walls being opposite to a second inner wall and defining a second gap between them, the second direction intersecting the expansion direction of the battery cell assembly.

[0013] In some embodiments, the width b of the second gap along the second direction satisfies:

[0014] b > (L1 - L2) / 2;

[0015] Wherein, b is the width of the second gap along the second direction, L1 refers to the minimum width of the mounting hole in the second direction, and L2 refers to the maximum width of the mounting post in the second direction.

[0016] In some embodiments, the mounting post has an elastic element on one side in the first direction. The elastic element is configured to elastically deform when the mounting post is inserted into the mounting hole and to contact the inside of the mounting hole after insertion.

[0017] In some embodiments, the elastic element includes a vertical section and an inclined section, one end of the inclined section is connected to the end of the vertical section away from the base body, and the end of the inclined section away from the vertical section is connected to the mounting column;

[0018] When the elastic element is located within the mounting hole, the vertical section is parallel to and in contact with the inner wall of the mounting hole.

[0019] In some embodiments, the elastic strain ε of the elastic element satisfies:

[0020] ε=(f×d) / (0.67×H 2 ×Q×r);

[0021] Where f is the required deformation of the elastic element, d is the wall thickness of the elastic element in the first direction, H is the effective deformation height of the elastic element, Q is the base plane skew magnification factor, and r is the taper magnification factor.

[0022] In some embodiments, the first sidewall has two spaced-apart through slots to define a fixed section located between the two through slots;

[0023] The elastic element includes a connecting section and a fixing section, wherein the fixing section is disposed opposite to the inclined section and connected to it through the connecting section.

[0024] In some embodiments, the deflection force Fp of the elastic element satisfies:

[0025] Fp = ε × W² × t³ × E / (6 × H × Q);

[0026] Where ε is the elastic strain of the elastic element, W2 is the width of the elastic element in the second direction, which intersects with the expansion direction of the battery cell assembly, t3 is the thickness of the connecting section, and E is the flexural modulus of the elastic element.

[0027] In some embodiments, the mounting hole includes a recess located on the first inner wall, and the recess protrudes toward the battery module in a first direction, so that the mounting hole is divided into a main hole and a secondary hole that communicate with each other in the first direction; the first direction is opposite to the expansion direction of the battery cell assembly.

[0028] The elastic element is used to insert into the secondary hole and contact the bottom wall of the recess, and the mounting post is used to insert into the main hole.

[0029] In some embodiments, when the elastic member is in an undeformed state, there is a deformation gap between the inner wall of the elastic member facing the mounting post and the first side wall, and the width of the deformation gap in the first direction is greater than the width of the first gap in the first direction.

[0030] Secondly, embodiments of this application provide a battery module, including:

[0031] Battery cell assembly;

[0032] Output terminal connector, connected to the total output terminal of the battery cell assembly;

[0033] A mounting assembly for mounting the battery cell assembly, the mounting assembly having mounting holes;

[0034] The output electrode base as described in the first aspect is at least partially inserted into the mounting hole and connected to the output electrode connector.

[0035] The beneficial effects of the embodiments of this application are as follows:

[0036] In the embodiments of this application, to address the issue that when the battery cell assembly undergoes thermal expansion, the mounting component may shift due to the expansion, thus affecting the connection reliability of the output electrode connector rigidly connected to the mounting component. A first gap is provided between the mounting post along the first direction towards the first sidewall of the battery cell assembly and the mounting hole along the first direction near the first inner wall of the battery cell assembly. This allows the mounting component to have a certain degree of free displacement relative to the output electrode base, preventing the initial deformation of the battery cell assembly from being immediately transmitted to the output electrode base through the rigid connection structure. This effectively isolates part of the expansion force transmission path to the output electrode connector. Consequently, the additional mechanical stress borne by the output electrode connector can be effectively reduced, decreasing the risk of failures such as solder joint cracking and poor connection caused by stress concentration. While ensuring the installation reliability of the output electrode connector, the safety and long-term reliability of the battery module are improved. Attached Figure Description

[0037] Figure 1 The diagram shown is a partial structural schematic of a battery module provided in an embodiment of this application.

[0038] Figure 2 The diagram shown is a partial exploded view of a battery module provided in an embodiment of this application.

[0039] Figure 3 The diagram shown is a structural schematic of an output electrode base provided in an embodiment of this application.

[0040] Figure 4 The diagram shown is a cross-sectional view of an output electrode base assembled with a mounting assembly in a second direction, according to an embodiment of this application.

[0041] Figure 5 The diagram shown is a cross-sectional view in the vertical direction of an output electrode base assembled with a mounting assembly according to an embodiment of this application.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1. Mounting components; 11. Mounting holes; 111. First inner wall; 112. Second inner wall; 113. Recess; 114. Main hole; 115. Secondary hole; 2. Output electrode base; 21. Base body; 22. Mounting post; 221. First side wall; 222. Second side wall; 23. Elastic element; 231. Vertical section; 232. Inclined section; 233. Connecting section; 234. Fixing section; 2341. Through slot; 3. Output electrode connector; 31. Busbar; 32. Copper busbar; 4. Bolts. Detailed Implementation

[0044] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] Embodiments of this application provide an output electrode base 2 for connecting to an output electrode connector 3 in a battery module. The output electrode connector 3 can be a copper busbar 32 or a busbar 31. Figures 1 to 5 As shown, the battery module includes a mounting assembly 1 for mounting a cell assembly (not shown in the figure). The mounting assembly 1 includes a housing, a top cover, and an end plate. The end plate is provided on at least one side of the cell assembly, and both the cell assembly and the end plate are located within the housing. The top cover is located on the opening side of the housing for housing the cell assembly. The cell assembly can consist of at least one cell. In this embodiment, the cell assembly is composed of multiple cells connected in series, parallel, or in a mixed configuration, or it can consist of at least one cell assembly. A mixed configuration refers to a group of cells connected in series and another group connected in parallel. The specific structure of the battery module is prior art and will not be described in detail here. The copper busbar 32 and the busbar 31 can both be connected to the output electrode base 2 by bolts 4. The output electrode base 2 is mounted on the mounting assembly 1 through mounting holes 11. The output electrode base 2 can be at least partially inserted into the mounting holes. It should be noted that the output electrode base 2 can be mounted on either the end plate or the housing, depending on the structure of the battery module. If the output electrode base 2 is mounted on the housing, the housing needs to have mounting holes 11; if the output electrode base 2 is mounted on the end plate, the end plate needs to have mounting holes 11. The output electrode base 2 is inserted into the mounting holes 11 through its structural design to support and position the output electrode connector 3.

[0046] Specifically, the output electrode base 2 includes a base body 21 and a mounting post 22. The base body 21 is used to fix the output electrode connector 3, and the copper busbar 32 or busbar 31 is usually fastened to its upper surface by bolts 4. The mounting post 22 is connected to one side of the base body 21 and extends in a direction perpendicular to the base body 21. It is used to insert into the mounting hole 11 on the mounting assembly 1, thereby assembling the entire output electrode base 2 onto the battery module.

[0047] The key point is that, along the first direction, the mounting post 22 has a first sidewall 221 facing the cell assembly, and the mounting hole 11 has a first inner wall 111 close to the cell assembly, with a first gap between the first sidewall 221 and the first inner wall 111. Here, the first direction is defined as the direction opposite to the expansion direction of the cell assembly. For example, in a square cell assembly, the cells mainly expand along the X-direction during charging and discharging, so the first direction is the −X-direction. In this case, the first gap is reserved between the side of the mounting post 22 facing the cell assembly and the inner wall of its corresponding mounting hole 11.

[0048] The existence of this first gap allows the mounting component 1 to move freely relative to the output electrode base 2 when the battery cell assembly expands due to heat and pushes the mounting component 1 along the expansion direction. This allows the mounting component 1 to move freely without immediately causing the output electrode base 2 to move as a whole. In other words, in the initial stage of expansion, the output electrode base 2 is not forcibly pulled, and the output electrode connector 3 (such as the busbar 31) connected to it will not immediately bear the tension transmitted by the deformation of the battery cell assembly. This effectively weakens the direct transmission path of the expansion force to the output electrode connection area. Without changing the basic mounting function of the output electrode base 2, it achieves partial decoupling of the module's expansion stress. This not only avoids the risk of cracking or loose connection at the solder joints between the battery cell terminals and the busbar 31 due to continuous high stress, but also ensures the installation stability and electrical reliability of the output electrode connector 3 under non-expansion conditions, thereby significantly improving the structural safety and operational stability of the battery module throughout its entire life cycle.

[0049] Please see Figure 4 and Figure 5 In some embodiments, based on the aforementioned output electrode base 2, to further ensure that the battery module can effectively mitigate the impact of expansion stress on the output electrode connector 3 under various operating conditions, this embodiment satisfies the following regarding the width c of the first gap along the first direction:

[0050] c = m + n.

[0051] Specifically, the width of the first gap is denoted as c, and its value consists of two parts: m and n. m refers to the minimum moving distance required for the installation component 1 to ensure that the tensile force on the output electrode connector 3 does not exceed the set safety threshold. This minimum moving distance m is obtained through simulation: based on the actual expansion of the battery pack, material stiffness, and connection structure layout, a mechanical model is established to simulate the tensile force transmitted to the output electrode connection area during the expansion of the module; by iteratively adjusting the displacement, the relative displacement required between the installation component 1 and the output electrode base 2 is determined when the tensile force on the output electrode connector 3 is exactly equal to or slightly lower than the ultimate tensile force that the battery cell terminal or busbar 31 structure can withstand. This displacement is m.

[0052] n represents the tolerance allowance for the assembly of mounting post 22 and mounting hole 11, used to compensate for unavoidable dimensional deviations during manufacturing and assembly. For example, the machining of mounting hole 11 may have a positional or dimensional tolerance of ±0.1 mm, and the injection molding of output electrode base 2 may also involve shrinkage deformation. If designed solely based on the theoretical clearance m, the clearance may be completely offset under the most unfavorable tolerance combination, causing the structure to degenerate into a rigid connection and lose its buffering effect. Therefore, an additional tolerance allowance n needs to be reserved, typically 0.2-0.5 mm, to ensure that the first clearance always exists effectively under all mass production conditions.

[0053] In some embodiments, see Figure 5 The second direction is located in the same plane as the expansion direction of the battery cell assembly and is perpendicular to it. For example, if the battery cell assembly expands along the X direction, the second direction is the Y direction in the XY plane. Along the second direction, the mounting hole 11 has two opposing second inner walls 112, and correspondingly, the mounting post 22 also has two opposing second side walls 222. The second side wall 222 located on the same side of the mounting post 22 is opposite to the second inner wall 112 of the mounting hole 11, defining a second gap between them. The existence of this second gap is not to provide expansion buffer, but to balance the contradiction between assembly freedom and positioning accuracy. Firstly, while a completely gapless interference fit can enhance anti-rotation capability, it can easily lead to installation difficulties due to manufacturing tolerances in actual assembly, and may even cause local stress concentration and deformation of the mounting post 22. Secondly, if the gap is too large, the mounting post 22 may rotate or wobble slightly during bolt 4 tightening or module vibration, affecting the positional stability of the output electrode connector 3. Thirdly, it can also ensure that the mounting assembly 1 moves relative to the mounting post 22 when subjected to the compression of the cell expansion, avoiding difficulties in moving the mounting assembly 1 due to the lack of gap.

[0054] Further, please see Figure 5The width of the second gap along the second direction is denoted as b, which must satisfy the relationship: b > (L1 − L2) / 2. Here, L1 is the minimum width of the mounting hole 11 in the second direction, taking into account the downward deviation during the machining process of the mounting hole 11; L2 is the maximum width of the mounting post 22 in the second direction, taking into account the upper limit of dimensions caused by factors such as injection molding shrinkage and mold wear. Therefore, (L1 − L2) / 2 essentially represents the theoretical minimum gap that may occur between one side of the mounting post 22 and the inner wall of the mounting hole 11 under the most unfavorable tolerance combination. If the actual second gap b is not greater than this theoretical minimum value, then in extreme cases, the mounting post 22 may completely fit or even interfere with one side of the mounting hole 11. This would cause the mounting post 22 to be laterally squeezed during the outward deformation of the beam or end plate when the module expands, preventing it from freely releasing displacement in the first direction. In severe cases, it may even hinder the normal absorption of expansion deformation, causing the structure to degenerate into a rigid connection and lose the effect of using the first gap for displacement buffering.

[0055] Therefore, by setting b>(L1−L2) / 2, it can be ensured that even under extreme conditions of overlapping manufacturing tolerances, the mounting post 22 still retains a small but effective space of movement in the second direction. This space is insufficient to allow significant rotation and also avoids mechanical jamming caused by thermal expansion or assembly stress, thereby ensuring that the first gap can function as expected during module expansion, giving the mounting assembly 1 a tendency to move relative to the mounting post 22.

[0056] For example, in one specific embodiment, the minimum dimension of the mounting hole 11 in the second direction is 20.4 mm, i.e., L1 = 20.4 mm; the corresponding dimension of the mounting post 22 is 20 ± 0.2 mm, i.e., L2 = 20.2 mm. At this time, (L1 − L2) / 2 = (20.4 − 20.2) / 2 = 0.1 mm, so as long as the second gap b is greater than 0.1 mm, the risk of jamming can be effectively avoided.

[0057] In some embodiments, based on the output electrode base 2, considering that the mounting post 22 is usually made of engineering plastics, such as PBT+GF20, PA66, etc., although its strength can meet general support requirements, when the output electrode connector 3 is tightened by bolts 4, the mounting post 22 may locally bear a large load. During the bolt tightening process, stress concentration can easily lead to plastic deformation or even cracking, thus affecting the installation accuracy and long-term reliability of the output electrode base 2, and also affecting the dimensions of the first and second gaps. Therefore, this embodiment quantitatively evaluates the stress state of the mounting post 22 during the bolt 4 assembly process and optimizes the geometric parameters of the mounting post 22 accordingly.

[0058] Specifically, please see Figures 1 to 5During the installation of the output terminal connector 3 onto the base body 21, the stress borne by the mounting post 22 is denoted as δ, and this stress can be estimated using the following formula:

[0059] δ = T1×1000 / (t1×t2×W1).

[0060] Wherein, T1 is the torque applied during the installation of the output pole connector 3 onto the base body 21 by the fastening bolt 4, for example, the typical value of M6 bolt 4 for pure aluminum busbar 31 is 7±1 N·m; t1 is the length of the mounting post 22 along the direction of insertion into the mounting hole 11; t2 is the wall thickness of the mounting hole 11 in the first direction, representing the effective support thickness of the mounting assembly 1 at that location; W1 is the straight edge length of the mounting post 22 in the first direction, which is used to determine the contact area between the mounting post 22 and the mounting hole 11, especially during the tightening of the bolt 4, the mounting post 22 undergoes a slight offset, causing the side of the mounting post 22 to contact the inner wall of the mounting hole 11.

[0061] As can be seen from the formula, increasing t1, t2, and W1 all help reduce the local stress of the mounting post 22. Of particular note is that increasing W1 not only increases the contact area but also effectively improves the torsional stiffness of the mounting post 22, preventing deflection when the bolt 4 is tightened. Therefore, within the limits of structural tolerances, W1 can be increased as much as possible to distribute the local load caused by the preload of the bolt 4.

[0062] For example, in actual design, it is necessary to ensure that the calculated δ is less than the allowable strength of the material used for mounting column 22, for example, the allowable strength of the material is 95 MPa. Taking a specific embodiment as an example: T1 is 8 N·m, t1=20mm, t2=2.3mm, W1=7mm, then δ≈24.8 MPa, which is far below the material strength limit, indicating that the structure has no risk of failure during assembly.

[0063] In some embodiments, see Figures 3 to 5 The mounting post 22 has an elastic element 23 on one side in the first direction. The elastic element 23 is configured to elastically deform when the mounting post 22 is inserted into the mounting hole 11, and to contact the inner side of the mounting hole 11 after being inserted into place. The elastic element 23 can be integrally molded with the mounting post 22 and is made of the same engineering plastic material as the base body 21, and has good elastic recovery performance.

[0064] During assembly, the output electrode base 2 is pressed into the mounting hole 11 on the mounting assembly 1 in a direction perpendicular to the base body 21. During this process, the elastic element 23 assists the mounting post in inserting into the mounting hole 11, serving a positioning function. Once the mounting post 22 is fully inserted into the mounting hole 11, the elastic element 23 can contact the inner wall of the mounting hole 11. Furthermore, because the elastic element 23 is elastic, it deforms with the expansion of the battery cell, preventing it from obstructing the movement of the mounting assembly 1. In summary, by utilizing the elastic element 23, both positioning of the mounting post 22 and the mounting hole 11 are achieved, and it ensures that the mounting assembly 1 can move relative to the mounting post 22 under the compressive force of the expanding battery cell, thus reducing the gap between the mounting post 22 and the mounting hole 11.

[0065] It is worth noting that, since the elastic element 23 itself has a certain degree of flexibility, it can absorb minor assembly deviations while avoiding stress concentration caused by rigid interference, thereby further improving the robustness of the structure.

[0066] Furthermore, the elastic element 23 includes a vertical segment 231 and an inclined segment 232. One end of the inclined segment 232 is connected to the end of the vertical segment 231 away from the base body 21, and the end of the inclined segment 232 away from the vertical segment 231 is connected to the mounting post 22. When the elastic element 23 is located within the mounting hole 11, the vertical segment 231 is parallel to and in contact with the inner wall of the mounting hole 11. The elastic element 23 engages with the side wall of the mounting post 22 in a hook shape. It should be noted that the inclination angle of the inclined segment 232 is based on the extension line of the vertical segment 231, that is, the inclination angle at which the extension line of the inclined segment 232 intersects the extension line of the vertical segment 231 ranges from 1° to 20°.

[0067] When the output electrode base 2 is pressed into the mounting hole 11, the inclined section 232 first contacts the edge of the inlet of the mounting hole 11. Due to its guide slope, it can convert radial resistance into a component force along the insertion direction, thereby reducing the initial assembly force and guiding the mounting post 22 smoothly into the hole. As the pressing depth increases, the inclined section 232 continues to deform under pressure, causing the vertical section 231 to deflect towards the body of the mounting post 22. After the mounting post 22 is fully in place, the elastic element 23 springs back as a whole, at which point the vertical section 231 returns to a basically vertical state and remains parallel to and in contact with the inner wall of the mounting hole 11. Of course, in other embodiments, when the mounting post 22 is inserted into the mounting hole 11, it is not necessary to use the guide slope of the inclined section 232 to abut against the inner wall of the mounting hole 11. Instead, the elastic member 23 and the mounting post 22 can be positioned with the mounting hole 11 by relying on their structure, so that the elastic member 23 and the mounting post 22 can be smoothly inserted into the mounting hole 11. After being inserted into place, the elastic member 23 and the inner wall of the mounting hole 11 can be a transition fit, an interference fit, or a clearance fit.

[0068] In some embodiments, see Figure 5 , the mounting hole 11 includes a recess 113. The recess 113 is provided on the first inner wall 111, and the recess 113 protrudes towards the battery module in the first direction, thereby dividing the entire mounting hole 11 into two interconnected parts in the first direction: a main hole 114 for mounting the mounting post 22 and a secondary hole 115 for mounting the elastic member 23. In other words, the mounting post 22 of the output pole base 2 is for inserting into the main hole 114, and the elastic member 23 provided on the first-direction side of the mounting post 22 correspondingly inserts into the secondary hole 115. When the assembly is in place, the vertical section 231 of the elastic member 23 contacts the recess 113 in the area of the secondary hole 115.

[0069] By providing the recess 113, the mounting hole 11 is divided into the main hole 114 and the secondary hole 115. On the one hand, since the secondary hole 115 only needs to accommodate the elastic member 23, its size can be made smaller, which is beneficial to improving the local stiffness. On the other hand, the main hole 114 and the secondary hole 115 are connected in the first direction, ensuring that the entire mounting post 22 can still absorb the expansion displacement of the module through the first gap and will not lose the buffering function due to structural separation. Also, the fit between the mounting post 22 and the inner wall of the main hole 114 can play a limiting role to prevent the elastic member 23 from being damaged due to excessive deformation. Specifically, when the expansion deformation of the battery cell is too large and the allowance of the first gap is not enough to satisfy the movement amount of the mounting assembly 1 relative to the mounting post 22, the side wall of the main hole 114 will contact the mounting post 22, playing a limiting role to avoid excessive deformation of the elastic member 23 and ensuring the reliability of the elastic member 23.

[0070] Exemplarily, in a specific embodiment, the first inner wall 111 is provided on both sides of the recess 113 in the second direction, and the recess 113 protrudes from the first inner wall 111 in the first direction. Looking from a perspective facing and perpendicular to the recess 113, it is equivalent to forming a groove at the first inner wall 111, making the overall shape of the mounting hole 11 a "convex" shape.

[0071] In some embodiments, when the elastic element 23 is in a free state, without external force (i.e., in an undeformed state), a deformation gap z is reserved between the inner wall of the elastic element 23 facing the mounting post 22 and the first side wall 221 of the mounting post 22 in the first direction. The width of this deformation gap z along the first direction directly determines the maximum displacement that the elastic element 23 can deform under pressure. In other words, when the output electrode base 2 is inserted into the mounting hole 11, the elastic element 23 is pressed against the mounting post 22 body by the inner wall of the mounting hole 11, generating initial elastic deformation. Of course, in other embodiments, the elastic element 23 and the inner wall of the mounting hole 11 may also be unforced in the initial state, i.e., only maintaining contact or clearance fit with each other; when the battery module expands subsequently, the mounting assembly 1 drives the mounting hole 11 to move further along the expansion direction, causing the elastic element 23 to undergo additional compressive deformation. At this time, if the maximum deformable amount of the elastic element 23 is insufficient, it may crack or permanently deform due to strain exceeding the material limit. Therefore, in this embodiment, the width of the deformation gap z in the first direction is set to be greater than the width of the first gap in the first direction. Here, the first gap represents the maximum displacement that the mounting component 1 needs to release relative to the output pole base 2 during the module expansion process. By ensuring that the deformation gap z is greater than the first gap, it can be guaranteed that even under the most unfavorable operating conditions, the total deformation required by the elastic element 23 is still less than the maximum deformation capacity allowed by its structure, thus always operating within the elastic range.

[0072] It is worth noting that, firstly, to ensure the insertion stability of the elastic element 23, the height of the vertical section 231 needs to take into account the wall thickness of the mounting hole 11 and the possible Z-direction displacement of the output electrode base 2 after tightening the bolts 4 of the copper busbar 32 or busbar 31. For example, in a specific embodiment, to avoid poor soldering between the output electrode busbar 31 and the cell terminal due to the accumulation of height tolerance, a 1 mm gap is reserved between them; taking into account factors such as the thickness of the adhesive layer at the bottom of the battery module, the height of the cell, the crossbeam of the casing, and the manufacturing tolerance of the output electrode base 2, the distance between the lower edge of the vertical section 231 of the elastic element 23 and the lower edge of the inner wall of the mounting hole 11 is finally set to 2.5 mm to ensure sufficient contact and no interference after assembly.

[0073] Secondly, in the expansion direction of the battery cell assembly, a third gap a is provided between the inner wall of the mounting hole 11 away from the elastic member 23 and the outer wall of the mounting post 22 away from the elastic member 23. This gap is mainly used to compensate for the manufacturing tolerances of the mounting hole 11 and the mounting post 22 in the width direction, i.e., the expansion direction of the battery cell assembly. This third gap a is generally 0.1-0.2 mm, and in this embodiment, it is 0.1 mm. This allows for a slight interference to improve the positioning effect, while avoiding assembly difficulties caused by the superposition of tolerances.

[0074] Further, please see Figure 4 and Figure 5When the mounting assembly 1 is displaced by the expansion force of the battery cell assembly, it compresses the elastic element 23 of the output electrode base 2, causing the elastic element 23 to deform. To ensure the reliability of the elastic element 23 and prevent breakage, the elastic strain of the elastic element 23 must be less than the allowable strain of the material used in the output electrode base 2, such as the commonly used PBT+GF20 material. The formula for calculating the elastic strain ε of the elastic element 23 is:

[0075] ε=(f×d) / (0.67×H 2 ×Q×r);

[0076] Where f is the required deformation of the elastic element 23 determined by simulation, d is the wall thickness of the elastic element 23 in the first direction, H is the effective deformation height of the elastic element 23, Q is the base plane skew magnification factor, which is related to the ratio of H / d and can be obtained from the snap-fit ​​design manual, and r is the taper magnification factor. In this embodiment, the elastic element 23 adopts a non-tapered, uniform width design, so r=1. In a specific case, m=2 mm, d=1.5 mm, H=10.8 mm, Q=1.63, and the calculated ε=2.36%, which is lower than the allowable strain of commonly used material PBT+GF20, about 2.5%, indicating that the structure is safe.

[0077] To further enhance flexibility, please refer to Figure 3 The first sidewall 221 has two spaced-apart through slots 2341 to define a fixed section 234 located between the two through slots 2341. The elastic member 23 includes a connecting section 233 and the fixed section 234 defined by the through slots 2341. The fixed section 234 is disposed opposite to the inclined section 232 and connected by the connecting section 233, which is arc-shaped. The length of the through slots 2341 in the insertion direction is 0.5 to 0.8 times the total height of the elastic member 23. At the same time, to facilitate injection molding, a demolding gap g of not less than 0.4 mm is maintained between the top of the elastic member 23, i.e., the top of the vertical section 231, and the bottom of the base body 21. By using the two through slots 2341 to define the fixed section 234, which forms part of the elastic member 23, it is beneficial to improve the flexibility and deformability of the elastic member 23.

[0078] Furthermore, the elastic element 23 generates a biasing force during deformation. If this force is too large, it may reverse the pressure on the output electrode base 2, indirectly increasing the stress on the output electrode connector 3. Therefore, this embodiment includes a formula for calculating the biasing force, as follows:

[0079] Fp = ε × W² × t³ × E / (6 × H × Q)

[0080] Where ε is the elastic strain of elastic element 23, W2 is the width of elastic element 23 in the second direction, typically 2-5 mm, t3 is the thickness of connecting section 233, E is the flexural modulus of elastic element 23, H is the effective deformation height of elastic element 23, and Q is the base plane skew amplification factor. In one example, W2 = 4 mm, t3 = 1.5 mm, E = 7100 MPa, and the remaining parameters follow the data given in the previous embodiment. Finally, the skew force Fp ≈ 14.3 N is calculated.

[0081] In summary, through the optimization of the geometric parameters of the elastic element 23, the dual verification of strain and skew force, and the coordinated cooperation with the mounting hole 11, this application achieves high-precision installation while effectively taking into account expansion buffering, fatigue resistance and manufacturing feasibility, significantly improving the overall reliability of the battery module output electrode connector 3.

[0082] This application also provides a battery module, which includes an output electrode base 2 as described in any of the foregoing embodiments, and further includes a cell assembly, an output electrode connector 3, a housing, an end plate, a top cover, and other structures. The housing, top cover, and end plate are all part of the mounting assembly 1. The output electrode connector 3 is connected to the total output terminal of the cell assembly; the mounting assembly is used to mount the cell assembly, and the mounting assembly has mounting holes 11; the output electrode base 2 is at least partially inserted into the mounting holes 11 and connected to the output electrode connector 3.

[0083] It should be noted that a battery cell assembly can consist of multiple cells connected in series, parallel, or in a mixed configuration. A mixed configuration refers to a group of cells connected in series while others are connected in parallel.

[0084] Furthermore, since the focus of this application is on the structure of the output electrode base 2 and the cooperation between the output electrode base 2 and the mounting component 1, conventional structures such as the cell assembly, output electrode connector 3, and mounting component 1 will not be described in detail here. Since the battery module includes the output electrode base 2, it also has the same structure and beneficial effects as the output electrode base 2. The structure and beneficial effects of the output electrode base 2 have been clearly explained in the aforementioned embodiments concerning the output electrode base 2, and will not be repeated here.

[0085] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications or equivalent substitutions made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An output terminal base for connecting an output terminal connector in a battery module, characterized in that, The battery module includes a mounting assembly for mounting battery cells. The mounting assembly has mounting holes, and at least a portion of the output electrode base is inserted into the mounting holes. The output electrode base includes: The base body is used to connect the output electrode connector; The mounting post is connected to one side of the base body and inserted into the mounting hole; The mounting post has a first sidewall facing the battery cell assembly, the mounting hole has a first inner wall close to the battery cell assembly, and a first gap exists between the first sidewall and the first inner wall. The width c of the first gap along the first direction satisfies: c = m + n; Wherein, m refers to the minimum moving distance required by the mounting assembly, provided that the tensile force on the output electrode connector does not exceed the threshold, and n refers to the tolerance allowance for the assembly of the mounting post and the mounting hole, and the first direction is opposite to the expansion direction of the battery cell assembly.

2. The output electrode base according to claim 1, characterized in that, Along the second direction, the mounting hole has two opposing second inner walls, and the mounting post has two opposing second side walls, each of the second side walls being opposite to one of the second inner walls and defining a second gap between them, the second direction intersecting the expansion direction of the battery cell assembly.

3. The output electrode base according to claim 2, characterized in that, The width b of the second gap along the second direction satisfies: b > (L1 - L2) / 2; Wherein, L1 is the minimum width of the mounting hole in the second direction, and L2 is the maximum width of the mounting post in the second direction.

4. The output electrode base according to any one of claims 1 to 3, characterized in that, The mounting post has an elastic element on one side in the first direction. The elastic element is configured to elastically deform when the mounting post is inserted into the mounting hole and to contact the inside of the mounting hole after being inserted into place.

5. The output electrode base according to claim 4, characterized in that, The elastic element includes a vertical section and an inclined section. One end of the inclined section is connected to the end of the vertical section away from the base body, and the end of the inclined section away from the vertical section is connected to the mounting column. When the elastic element is located within the mounting hole, the vertical section is parallel to and in contact with the inner wall of the mounting hole.

6. The output electrode base according to claim 5, characterized in that, The elastic strain ε of the elastic element satisfies: ε = (f x d) / (0.67 x H 2 x Q x r); Where f is the required deformation of the elastic element, d is the wall thickness of the elastic element in the first direction, H is the effective deformation height of the elastic element, Q is the base plane skew magnification factor, and r is the taper magnification factor.

7. The output electrode base according to claim 6, characterized in that, The first sidewall has two spaced-apart through slots to define a fixed section located between the two through slots; The elastic element includes a connecting section and a fixing section, wherein the fixing section is disposed opposite to the inclined section and connected to it through the connecting section.

8. The output electrode base according to claim 7, characterized in that, The deflection force Fp of the elastic element satisfies: Fp = ε × W² × t³ × E / (6 × H × Q); Where ε is the elastic strain of the elastic element, W2 is the width of the elastic element in the second direction, which intersects with the expansion direction of the battery cell assembly, t3 is the thickness of the connecting section, and E is the flexural modulus of the elastic element.

9. The output electrode base according to claim 4, characterized in that, The mounting hole includes a recess located on the first inner wall, and the recess protrudes toward the battery module in a first direction, so that the mounting hole is divided into a main hole and a secondary hole that communicate with each other in the first direction, the first direction being opposite to the expansion direction of the battery cell assembly; The elastic element is used to insert into the secondary hole and contact the bottom wall of the recess, and the mounting post is used to insert into the main hole.

10. The output electrode base according to claim 4, characterized in that, When the elastic element is in an undeformed state, there is a deformation gap between the inner wall of the elastic element facing the mounting post and the first side wall, and the width of the deformation gap in the first direction is greater than the width of the first gap in the first direction.

11. A battery module, characterized in that, include: Battery cell assembly; Output terminal connector, connected to the total output terminal of the battery cell assembly; A mounting assembly for mounting the battery cell assembly, the mounting assembly having mounting holes; The output electrode base as described in any one of claims 1 to 10 is at least partially inserted into the mounting hole and connected to the output electrode connector.

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