Battery modules and battery packs

Abstract

To provide a battery module and a battery pack.SOLUTION: A battery module and a battery pack are provided. The battery module includes an end plate, a pressure welding bar, and a battery cell. A plurality of battery cells are sequentially arranged along a first direction to form a battery cell group. Two end plates abut on both ends of the battery cell group, respectively. The pressure welding bar includes a pressure welding bar body and a connection assembly. The pressure welding bar body extends along a first direction. The connection assembly is connected to at least one end of the pressure welding bar body in the first direction. The pressure welding bar is pressed against the battery cell group. The connection assembly is movably abutted on a side of the end plate away from the battery cell group.SELECTED DRAWING: Figure 1

Description

【Technical Field】 【0001】 This application relates to the field of battery technology, specifically to battery modules and battery packs. 【0002】 This application claims the priority of a Chinese patent application with the application number 202323529198.6 filed with the Chinese Patent Office on December 22, 2023, and all the contents of this application are incorporated herein by reference. 【Background Art】 【0003】 With the rapid development of the new energy vehicle market, the safety of the power battery system has become the focus of the industry. The modularization technology of battery modules is an important direction in the integrated design of battery packs. Since battery modules have end plates, side plates, and straps for binding, the structural stability of battery modules is better than that of CTP (Cell-to-Pack) battery packs. 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 In related technologies, the modular design methods related to battery modules usually adopt solutions regarding thick end plates and side plates, or lightweight them. As a result, insufficient binding to battery cells is caused, resulting in insufficient structural strength throughout the life cycle of the battery module, leading to irreversible expansion deformation or affecting the cycle life of the battery module. 【Means for Solving the Problems】 【0005】 This invention provides a battery module. The battery module includes end plates, a pressure bar, and battery cells. Multiple battery cells are arranged sequentially along a first direction to form a group of battery cells. Two end plates abut against each end of the group of battery cells, respectively. The pressure bar includes a pressure bar body and a connecting assembly, the pressure bar body extending along the first direction, and the connecting assembly connected to at least one end of the pressure bar body in the first direction. The pressure bar is pressed against the group of battery cells, and the connecting assembly is movably abutted against the side of the end plate away from the group of battery cells. 【0006】 The present invention further provides a battery pack, which includes the battery module described above. [Effects of the Invention] 【0007】 The battery pack provided in this application forms a battery cell group by arranging battery cells sequentially along a first direction, and then forms a frame for the battery cells of the battery cell group with two end plates that abut against both ends of the battery cell group and a pressure contact bar connected to the two end plates, thereby serving to restrain the battery cell group in each direction. Furthermore, the pressure contact bar and the end plates are movably brought into contact by a connecting assembly provided at least one end of the pressure contact bar body, and the connecting assembly movably abuts against the end plates, bringing the end plates at both ends closer together until the battery cell group is tightened, thereby increasing the restraining force on the battery cell group along the first direction, thereby further improving the restraining effect of the battery cell group in the first direction, and consequently ensuring the resistance to expansion in each direction of the battery module, and ensuring that the structure of the battery module is stable and reliable throughout its entire lifecycle. 【0008】 The battery pack provided in this application ensures resistance to expansion in all directions of the battery pack by installing the aforementioned battery module, thereby ensuring that the battery pack remains structurally stable and reliable throughout its entire lifecycle. [Brief explanation of the drawing] 【0009】 [Figure 1]This is a schematic three-dimensional diagram showing a battery module provided in an embodiment of the present invention. [Figure 2] This is an exploded view showing a battery module provided in an embodiment of the present application. [Figure 3] This is a schematic diagram showing the structure of a pressure-welding bar provided in an embodiment of the present application. [Figure 4] This is an enlarged view of part A in Figure 3. [Figure 5] This is a schematic diagram showing the end plate provided in the embodiment of the present application. [Figure 6] This is a schematic diagram showing the structure of a battery pack provided in an embodiment of the present invention. [Modes for carrying out the invention] 【0010】 In the description of this application, unless otherwise explicitly stated and limited, the terms “connected to one another,” “connected,” and “fixed” shall be understood in a broad sense. For example, a fixed connection may be a detachable connection, a one-piece connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection through an intermediate medium, an internal communication between two elements, or an interaction between two elements. Those skilled in the art may understand the specific meaning of the above terms in this application in particular contexts. 【0011】 In this application, unless otherwise explicitly stated or limited, the presence of a first feature "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or it may include the first feature not being in direct contact with the second feature but being in contact with it by other features between them. Furthermore, the presence of a first feature "above," "above," or "on the top surface" of a second feature indicates that the first feature is directly above or diagonally above the second feature, or that the first feature is higher than the second feature in the horizontal direction. The presence of a first feature "below," "below," or "on the bottom surface" of a second feature indicates that the first feature is directly below or diagonally below the second feature, or that the first feature is lower than the second feature in the horizontal direction. 【0012】 In the description of this embodiment, terms relating to orientation or positional relationships, such as "up," "down," "left," "right," "front," and "back," are based on the orientation or positional relationships shown in the drawings and are for the purpose of simplifying explanation and operation. They do not indicate or suggest any device or element having a specific orientation, configuration, or operation, and should not be interpreted as limiting this application. Furthermore, "first" and "second" are used for distinction in the description and do not have any special meaning. 【0013】 As shown in Figures 1 and 2, an embodiment of the present invention provides a battery module 10, which includes an end plate 1, a pressure contact bar 2, and a battery cell 3. 【0014】 Multiple battery cells 3 are arranged sequentially along a first direction X to form a battery cell group 4. 【0015】 The two end plates 1 are in contact with both ends of the battery cell group 4, respectively. 【0016】 Furthermore, the shape of the end plate 1 can be matched to the shape of the battery cell 3. For example, if the battery cell 3 is rectangular, the end plate 1 will also be rectangular. In addition, the dimensions of the end plate 1 can be matched to the dimensions of the battery cell 3. By arranging the end plate 1 and the battery cell 3 to match their dimensions, the binding effect of the end plate 1 on the battery cell 3 can be enhanced. 【0017】 As shown in Figure 3, the pressure-contact bar 2 includes a pressure-contact bar body 21 and a connecting assembly 22, the pressure-contact bar body 21 extending along a first direction X, and the connecting assembly 22 being connected to at least one end of the pressure-contact bar body 21 in the first direction X. 【0018】 The pressure bar 2 is pressed against the battery cell group 4, and the connecting assembly 22 is movably brought into contact with the side of the end plate 1 away from the battery cell group 4. 【0019】 For better understanding, the connection assembly 22 may be connected only to one end of the pressure contact bar body 21 in the first direction X, or may be simultaneously connected to both ends of the pressure contact bar body 21 in the first direction X. When the connection assembly 22 is connected only to one end of the pressure contact bar body 21 in the first direction X, the other end of the pressure contact bar body 21 is connected to the end plate 1 by a fixed connection method, and the end having the connection assembly 22 is movably abutted against the end plate 1. When the connection assembly 22 is simultaneously connected to both ends of the pressure contact bar body 21 in the first direction X, the connection assemblies 22 located at both ends are movably abutted against the two end plates 1 respectively. 【0020】 As an example, as shown in FIGS. 1 to 2, the battery cell 3 is a rectangular battery cell, and a plurality of battery cells 3 are arranged in order along the thickness direction to form a battery cell group 4, and the two end plates 1 are respectively abutted against both ends of the battery cell group 4. 【0021】 As shown in FIG. 3, the pressure contact bar 2 includes a pressure contact bar body 21 and a connection assembly 22. Here, the pressure contact bar body 21 extends along the first direction X, and the connection assembly 22 is connected to at least one end of the pressure contact bar body 21 in the first direction X. That is, the connection assembly 22 and the pressure contact bar body 21 are integrated, and the two connection assemblies 22 are respectively connected to the two end portions of the pressure contact bar body 21. 【0022】 The crimping bar 2 is pressed against the battery cell group 4, and the connection assembly 22 is movably abutted against the side of the end plate 1 away from the battery cell group 4. By pressing the crimping bar 2 against the battery cell group 4 and movably abutting the crimping bar 2 and the end plate 1 by the connection assembly 22, the end plate 1 and the crimping bar 2 are caused to form a frame of the battery cells used to bind the battery cell group 4, and play a role in binding in each direction of the battery cell group 4. On the other hand, the connection assembly 22 provided at the end of the crimping bar body 21 is movably abutted against the end plate 1, so that the end plates 1 at both ends are brought closer to each other until the battery cell group 4 is tightened, and the binding force along the first direction X with respect to the battery cell group 4 is increased. Thereby, the binding effect of the crimping bar 2 and the end plate 1 in the first direction X with respect to the battery cell group 4 is further improved, and thus the anti-expansion property of the battery module 10 in each direction is ensured, and the structure of the battery module 10 is stable and reliable within the entire life cycle. 【0023】 The pre-tightening force is one of the important indicators in the design of the battery module 10, and has a relatively large impact on the cycle life and initial rigidity of the battery module 10. However, in the related art, the battery module 10 usually adopts a design method of fixing the pre-tightening force. As a result, due to certain errors and variations in the dimensions of the battery cells 3, when the dimensions of the battery cells 3 constituting the battery module 10 change, the design method of fixing the pre-tightening force cannot adjust the initial pre-tightening force of the battery module 10 correspondingly. 【0024】 In some embodiments, as shown in FIG. 3, the connection assembly 22 includes a pre-tightening member 221 and a connection portion 222. The connection portion 222 is connected to at least one end of the crimping bar body 21, the pre-tightening member 221 is movably connected to the connection portion 222 along the first direction X, and the end of the pre-tightening member 221 away from the connection portion 222 is abutted against the end plate 1. 【0025】 In other words, the connection portion 222 is connected to the pressure-contact bar body 21. The pre-tightening member 221 is connected to the connection portion 222 along the first direction X, and the end of the pre-tightening member 221 away from the connection portion 222 abuts against the end plate 1, thereby realizing the connection between the pressure-contact bar 2 and the end plate 1. The pre-tightening member 221 also enables flexible adjustment of the pre-tightening force of the battery module 10, solving problems that tend to occur when the dimensions of the battery cell 3 fluctuate, such as the pre-tightening force exceeding or falling short of the standard, and also avoiding the cycle life being affected by the pre-tightening force of the battery module 10 exceeding or falling short of the standard. 【0026】 In some embodiments, as shown in Figure 5, the end plate 1 is further provided with a protrusion 11 extending along a first direction X, and one end of the protrusion 11 away from the end plate 1 is inserted into the connecting portion. 【0027】 By providing a protrusion 11 on the end plate 1 and inserting one end of the protrusion 11 away from the end plate 1 into the connecting portion 222, a positioning effect is provided to the end plate 1 and the pressure contact bar 2, thereby achieving a better connection between the end plate 1 and the pressure contact bar 2. 【0028】 The shape of the protrusion 11 may be cylindrical, rectangular, or any other shape. 【0029】 Furthermore, as shown in Figures 3-4, the connecting portion 222 is provided with a connecting hole 2221, the protrusion 11 is inserted into a part of the connecting hole 2221, and the pre-tightening member 221 penetrates another part of the connecting hole 2221 and comes into contact with the protrusion 11. 【0030】 The positioning effect is achieved by inserting the protrusion 11 into the connection hole 2221. On the other hand, the pre-tightening member 221 comes into contact with the protrusion 11 and the inside of the connection hole 2221, thereby connecting the end plate 1 and the pressure bar 2 and further increasing the compactness of the structure. 【0031】 Furthermore, when the battery cell group 4 expands, an outward expansion pressure is generated on the pressure contact bars 2 distributed around the battery cell group 4, increasing the radial force on the pre-tightening member 221, which in turn affects the pre-tightening adjustment and removal of the pre-tightening member 221. In contrast, the protrusion 11 provided on the end plate 1 provides a positioning effect and improves the radial position limiting effect. As a result, when the battery cell group 4 expands and deforms, the radial force on the pre-tightening member 221 is reduced when the battery module 10 deforms unevenly, thereby reducing the impact of the expansion of the battery cell group 4. 【0032】 In some embodiments, the pre-tightening member 221 is screwed into the connection hole 2221. 【0033】 The pre-tightening member 221 is screwed into the connection hole 2221, and the pre-tightening member 221 is connected to the pressure bar 2, thereby applying pressure to the end plate 1 and achieving connection between the pressure bar 2 and the end plate 1. Furthermore, the cooperation between the connection hole 2221 and the protrusion 11 provides a positioning effect, and the pre-tightening member 221 is connected to the connection hole 2221 by a screwing method, making it easy to flexibly adjust the pre-tightening force. 【0034】 For example, the pre-tightening member 221 may be a tightening adjustment bolt, and the connection hole 2221 may be a screw hole. 【0035】 In some embodiments, as shown in Figure 3, the contact bar body 21 includes a first contact portion 211 and a second contact portion 212, each extending along a first direction X, the second contact portion 212 being connected to one side of the first contact portion 211, and the first contact portion 211 and the second contact portion 212 being pressed against adjacent sides of a battery cell group, respectively, and both sides of the connection assembly 22 being connected to the first contact portion 211 and the second contact portion 212, respectively. 【0036】 The first and second pressure-contact portions 211 and 212 firmly press against adjacent sides of the battery cell group 4, respectively. The first and second pressure-contact portions 211 and 212 each serve to restrain the battery cell group 4 in different directions, thereby increasing structural strength in both directions. Through the cooperation of the multiple pressure-contact bars 2, the battery cell group 4 forms a more stable whole, significantly improving the overall rigidity of the battery module 10. 【0037】 Furthermore, the connection assembly 22 includes a connecting portion 222. Both sides of the connecting portion 222 are connected to the first contact portion 211 and the second contact portion 212, respectively. The connecting portion 222, the first contact portion 211, and the second contact portion 212 are perpendicular to each other. 【0038】 As an example, as shown in Figure 3, the first contact portion 211 and the second contact portion 212 are perpendicular to each other, that is, the contact bar body 21 has an "L" shaped structure, and the connecting portion 222 is perpendicular to the first contact portion 211 and the second contact portion 212, respectively. For the battery cell group 4 consisting of rectangular battery cells, the first contact portion 211 and the second contact portion 212, which are perpendicular to each other, can increase the structural strength in two directions. Furthermore, the first contact portion 211, the second contact portion 212, and the connecting portion 222, which are perpendicular to each other, can provide positioning and positional limiting effects in three directions of the end plate 1, thereby improving the structural stability of the battery module 10. 【0039】 The widths of the first contact portion 211 and the second contact portion 212 may be the same or different. In actual application, the widths and relative positions of the first contact portion 211 and the second contact portion 212 may be adjusted according to the degree of the binding effect that needs to be provided in different directions of the battery module 10. 【0040】 In some embodiments, at least two pressure contact bars 2 are installed, and each of the at least two pressure contact bars 2 is located diagonally opposite the battery cell group 4. 【0041】 The pressure contact bar 2 includes both a first pressure contact portion 211 and a second pressure contact portion 212. Since the first pressure contact portion 211 and the second pressure contact portion 212 serve to restrain the battery cell group 4 in two different directions, the two diagonally positioned pressure contact bars 2 can provide a good clamping and fixing effect to the battery cell group 4. The cooperation between the pressure contact bar 2 and the end plate 1 can provide a restraining effect to the battery cell group 4 in each direction. 【0042】 To make it easier to understand, increasing the number of pressure bars 2 can further improve the structural stability and provide a better binding effect to the battery cell group. For example, as shown in Figures 1-2, one pressure bar 2 is provided at each of the four corners of the battery cell group 4, which consists of rectangular battery cells. 【0043】 In some embodiments, as shown in Figure 2, the battery module 10 further includes an adhesive layer 6, which is provided between the pressure bar 2 and the battery cell group 4. 【0044】 In other words, the pressure contact bar 2 and the battery cell group 4 are bonded together by the adhesive layer 6 to form a sandwich structure. As an example, as shown in Figure 2, an adhesive layer 6 is provided between the "L" shaped pressure contact bar 2 and the battery cell group 4, which consists of rectangular battery cells. The adhesive layer 6 bonds the pressure contact bar 2 and the battery cell group 4, and also integrates the multiple battery cells 3 in the battery cell group 4. The pressure contact bar 2 not only plays a role in stabilizing the structure of the battery module 10 in the height and width directions, but also improves the structural stability of the battery module 10 in the height direction. 【0045】 In some embodiments, as shown in Figure 2, the battery module 10 further includes a foam 7, which is located between two adjacent battery cells 3 and / or between an end plate 1 and a battery cell 3 adjacent to the end plate 1. 【0046】 The foam 7 may be provided between the end plate 1 and the battery cell 3 adjacent to the end plate 1, or between adjacent battery cells 3 used to constitute the battery cell group 4, or it may be provided simultaneously at both of the above-mentioned locations. The foam 7 can limit the gap between the end plate 1 and the battery cell 3, and / or the gap between adjacent battery cells 3, thereby acting as a buffer. 【0047】 Furthermore, the foam 7 may have a hollow structure. The hollow foam 7 covers only the peripheral regions of the battery cells 3 and / or end plate 1, so that there is some gap between adjacent battery cells 3 or between the end plate 1 and the battery cells 3. This reduces the adjustment pressure when adjusting the pre-tightening force because the area of ​​the hollow foam 7 is relatively small, so it covers only the peripheral regions of the end plate 1 and / or the battery cells 3, resulting in relatively little resistance during the tightening adjustment process. On the other hand, forming cavities between the end plate 1 and the battery cells 3 and / or between adjacent battery cells 3 improves the overall heat dissipation performance of the booster battery module 10 and pre-secures expansion space between the battery cells 3. 【0048】 As an example, as shown in Figure 2, the battery cell 3 is a rectangular battery cell, and the foam body 7 is a corresponding box structure. The box structure foam body 7 is provided between adjacent battery cells 3 and between the end plate 1 and the battery cell 3. 【0049】 As shown in Figure 6, an embodiment of the present invention provides a battery pack 100, which includes the battery module 10 described above. 【0050】 The battery pack 100 may contain only one battery module 10, or it may contain multiple battery modules 10. 【0051】 By applying the aforementioned battery module 10 to the battery pack 100, the battery module 10 has good resistance to expansion in all directions, and its structure remains stable and reliable throughout its entire lifecycle, thereby improving the safety and reliability of the battery pack 100. [Explanation of symbols] 【0052】 10: Battery module 1: End plate 11: Convex part 2: Compression bar 21: Pressure bar body 211: First pressure-welded section 212: Second pressure-welded section 22: Connection Assembly 221: Pre-tightening component 222: Connection part 2221: Connection Hall 3: Battery cell 4: Battery cell group 6: Adhesive layer 7: Foam 100: Battery pack

Claims

[Claim 1] It includes an end plate, a pressure bar, and a battery cell, Multiple battery cells are arranged sequentially along a first direction to form a battery cell group. The two end plates are in contact with both ends of the battery cell group, The pressure-contact bar includes a pressure-contact bar body and a connecting assembly, the pressure-contact bar body extending along the first direction, and the connecting assembly connected to at least one end of the pressure-contact bar body in the first direction. The pressure bar is pressed against the battery cell group, and the connection assembly is movably abutted against the side of the end plate away from the battery cell group. The aforementioned connection assembly includes a pre-tightening member and a connecting portion, The connecting portion is connected to at least one end of the pressure-fitting bar body, the pre-tightening member is movably connected to the connecting portion along the first direction, and the end of the pre-tightening member away from the connecting portion abuts against the end plate. The end plate is further provided with a protrusion extending along the first direction, and one end of the protrusion away from the end plate is inserted into the connecting portion. The connecting portion is provided with a connecting hole, the protrusion is inserted into a part of the connecting hole, and the pre-tightening member penetrates another part of the connecting hole and abuts against the protrusion. Battery module. [Claim 2] The shape of the protrusion includes a cylindrical or rectangular shape. The battery module according to claim 1. [Claim 3] The pre-tightening member is screwed into the connection hole. The battery module according to claim 1. [Claim 4] The contact bar body includes a first contact portion and a second contact portion, the first and second contact portions each extending along the first direction, the second contact portion connected to one side of the first contact portion, the first and second contact portions pressed against adjacent sides of the battery cell group, and both sides of the connection assembly connected to the first and second contact portions, respectively. The battery module according to claim 1 or 2. [Claim 5] The aforementioned connection assembly includes a connecting portion, Both sides of the connecting portion are connected to the first and second pressure-welding portions, respectively, and the connecting portion, the first and second pressure-welding portions are perpendicular to each other. The battery module according to claim 4. [Claim 6] At least two of the aforementioned pressure contact bars are installed, and at least two of the pressure contact bars are positioned diagonally opposite each other in the battery cell group. The battery module according to claim 4. [Claim 7] The battery module further includes an adhesive layer, the adhesive layer being provided between the pressure bar and the battery cell group. The battery module according to claim 1 or 2. [Claim 8] The battery cell is a rectangular battery cell, and a plurality of the battery cells are arranged sequentially along the thickness direction to form the battery cell group, and the two end plates are in contact with both ends of the battery cell group, respectively. The battery module according to claim 1 or 2. [Claim 9] The battery module further includes a foam, the foam being located between two adjacent battery cells and / or between the end plate and the battery cell adjacent to the end plate. The battery module according to claim 1 or 2. [Claim 10] The foam has a hollow structure, and the hollow foam covers the peripheral region of the battery cells and / or the end plate such that there is a gap between adjacent battery cells or between the end plate and the battery cells. The battery module according to claim 9. [Claim 11] A battery module comprising the battery module described in claim 1 or 2, Battery pack.

Images