Split type connection structure, battery cell cover plate, power battery and power battery assembly

Abstract

The utility model provides a split type connecting structure, a battery core cover plate, a power battery and a power battery assembly, the split type connecting structure is suitable for the power battery, the power battery comprises one or more pole columns and one or more battery cores, the split type connecting structure comprises a pole column step, a pole column cover plate and a pole column cover plate, and the pole column step is located at the bottom of at least one pole column; the pole step comprises a first lap joint surface; the connecting piece comprises a first end face and a second end face which are opposite to each other, the connecting piece further comprises a connecting piece step arranged on the first end face, the connecting piece step comprises a second lap joint face, the second lap joint face is suitable for being in contact with the first lap joint face so that the first end face of the connecting piece can be connected with the pole column, and the second end face is suitable for being connected with the pole lug of the battery cell. According to the split type connection structure, the battery core cover plate, the power battery and the power battery assembly provided by the invention, the internal space of the battery can be saved, so that the battery capacity is improved.

Description

Technical Field

[0001] The present application mainly relates to the field of power batteries, and in particular to a split connection structure, a battery cell cover, a power battery and a power battery assembly. Background Art

[0002] Lithium battery soft connection welding is a method of connecting battery pole pieces with soft conductive materials. The principle is to use the pressure and current under high temperature to weld the flexible conductive material to the battery pole piece. The soft connection welding process uses flexible conductive materials, such as copper strips, aluminum strips, nickel strips, etc. These materials have good flexibility and conductivity, can effectively relieve the internal stress of the battery, reduce the generation of hot spots, and improve the safety and stability of the battery. Connector welding is a traditional welding process. The connection between battery pole pieces usually uses hard conductive materials such as copper foil or aluminum foil. This connection method is prone to generate hot spots and increase the internal pressure of the battery.

[0003] The connecting piece and the flexible connection are the key components for connecting the battery cover and the battery cell. It must take into account the battery's overcurrent, strength and low spatter requirements at the same time. Therefore, during the welding process with the cover, there needs to be a sufficient weld width, and it is necessary to ensure that no particles fall on the battery cell to avoid battery short circuit. Copper, as the negative electrode material, is a high-reflective material with low absorption rate, and requires higher energy density to weld.

[0004] The main function of the connecting piece is to connect the pole and the ear of the battery cell without affecting the overcurrent, thereby achieving electrical connection. At present, the connecting piece in this field mainly connects the battery cell ear and the pole by connecting to the pole base. The area of ​​the connecting piece is large, so the cost is also increased accordingly. At the same time, it also occupies a part of the internal space of the battery. Therefore, the connecting piece is an important part of reducing the cost of the battery structure. Utility Model Content

[0005] The technical problem to be solved by the present application is to provide a split connection structure, a battery cell cover, a power battery and a power battery assembly, which can save the internal space of the battery and thus increase the battery capacity.

[0006] To solve the above technical problems, the present application provides a split connection structure, which is suitable for a power battery, wherein the power battery includes one or more poles and one or more battery cells, and the split connection structure includes: a pole step, located at the bottom of at least one of the poles, and the pole step includes a first lap surface; a connecting plate, including a first end face and a second end face opposite to each other, wherein the connecting plate also includes a connecting plate step arranged on the first end face, and the connecting plate step includes a second lap surface, and the second lap surface is suitable for contacting with the first lap surface so that the first end face of the connecting plate is connected to the pole, and the second end face is suitable for connecting with the pole ear of the battery cell.

[0007] Optionally, the electrode column includes a positive electrode column, each of the battery cells includes a positive electrode lug, and the connecting piece includes a positive electrode connecting piece, and the positive electrode connecting piece is suitable for connecting the positive electrode lug and the positive electrode column, wherein the second overlapping surface of the positive electrode connecting piece contacts the first overlapping surface of the positive electrode column step to connect the positive electrode connecting piece and the positive electrode column; and the second end surface of the positive electrode connecting piece is connected to the positive electrode lug of the battery cell to connect the positive electrode column and the positive electrode lug through the positive electrode connecting piece.

[0008] Optionally, the electrode includes a negative electrode, each of the battery cells includes a negative electrode lug, and the connecting piece includes a negative electrode connecting piece, and the negative electrode connecting piece is suitable for connecting the negative electrode lug and the negative electrode, wherein the second overlapping surface of the negative electrode connecting piece contacts the first overlapping surface of the negative electrode step to connect the negative electrode connecting piece and the negative electrode; and the second end surface of the negative electrode connecting piece is connected to the negative electrode lug of the battery cell to connect the negative electrode column and the negative electrode lug through the negative electrode connecting piece.

[0009] Optionally, the battery cell includes a first battery cell and a second battery cell that are adjacent to each other, the positive electrode tab of the first battery cell and the positive electrode tab of the second battery cell are connected to the same positive electrode pole, and the negative electrode tab of the first battery cell and the negative electrode tab of the second battery cell are connected to the same negative electrode pole.

[0010] Optionally, the positive electrode connecting sheet is connected to the positive electrode lug and the positive electrode post by laser welding, and the negative electrode connecting sheet is connected to the negative electrode lug and the negative electrode post by laser welding.

[0011] Optionally, the width of the pole step ranges from 1mm to 5mm, the thickness ranges from 1mm to 2mm, the height of the vertical surface is 0.5mm to 1mm, the width of the connecting plate step ranges from 1mm to 5mm, the thickness ranges from 1mm to 2mm, the height of the vertical surface is 0.5mm to 1mm, and the contact length between the first overlapping surface and the second overlapping surface is 2mm to 3mm.

[0012] Optionally, the overall thickness of the lower end of the pole is 3 mm to 5 mm, and the overall thickness of the connecting piece is 3 mm to 5 mm.

[0013] In order to solve the above technical problems, the present application provides a battery cell cover plate, including: a pole, a pole step is arranged at the bottom of the pole, and the pole step includes a first overlapping surface, wherein the first overlapping surface is suitable for cooperating with the second overlapping surface of the connecting piece in the split connection structure as described above.

[0014] In order to solve the above technical problems, the present application provides a power battery, including: one or more battery cell cover plates, one or more battery cells, and the split connection structure as described above.

[0015] In order to solve the above technical problems, the present application provides a power battery assembly, comprising a plurality of cascaded power batteries as described above.

[0016] Compared with the prior art, the present application adopts the arrangement of a split connecting piece so that the connecting piece can be connected to the pole from the side without being connected to the pole base, which can effectively reduce the space of the connecting piece inside the battery and increase the internal capacity of the battery. At the same time, the structure and area of ​​the split connecting piece are smaller, which has the effect of simple structure and easy manufacturing, and can reduce the cost of the connecting piece. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present application. In the accompanying drawings:

[0018] Figure 1 It is a schematic diagram of a partial structure of a power battery in one embodiment of the present application;

[0019] Figure 2 It is a structural schematic diagram of a connecting piece in a split-type connecting structure in one embodiment of the present application;

[0020] Figure 3-4 This is a schematic diagram of the structure of a power battery in one working state in one embodiment of the present application;

[0021] Figure 5 It is a cross-sectional schematic diagram of a power battery in one embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0023] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0024] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0025] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0026] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0027] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0028] This application refers to Figure 1 and Figure 2 A split connection structure 10 (hereinafter referred to as "connection structure 10") is proposed, which is suitable for Figure 4 The power battery 100 shown in FIG. 1 includes a battery cover 300 and a battery cell 12 (see FIG. Figure 4 ), wherein the cell cover includes a pole 11, and the cell 12 further includes a first cell 21 and a second cell 22. Figure 1 is a partial schematic diagram of a power battery 100, Figure 2 is a schematic diagram of the structure of the connecting piece. Figure 4 Schematic diagram of the structure of the power battery 100.

[0029] Reference Figure 1 and Figure 2The connection structure 10 includes a pole step 101 and a connecting piece 102, wherein the pole step 101 is located at the bottom of the pole 11, and the pole step 101 includes a positive pole step 1011 and a negative pole step 1012, and both the positive pole step 1011 and the negative pole step 1012 include a first lap joint surface S1. Further, the connecting piece 102 includes a first end surface S11 and a second end surface S12 opposite to each other, and a connecting piece step 103 arranged on the first end surface, and the connecting piece step includes a second lap joint surface S2, and the second lap joint surface S2 is suitable for contacting with the first lap joint surface S1 so that the first end surface S11 of the connecting piece 102 is connected to the pole 11, and the second end surface S22 of the connecting piece 102 is suitable for contacting with the pole ear 14 of the battery cell 12 (refer to Figure 3 )connect.

[0030] A clearer reference Figure 3 and Figure 4 , Figure 3 FIG. 1 shows a schematic diagram of the structure of the power battery 100 when the connecting piece 102 is connected to the pole lug 14 but not yet connected to the pole 11. Figure 4 It shows a schematic structural diagram of the power battery 100 after the connecting piece 102 is connected to the pole lug 14 and the pole 11 .

[0031] Reference Figure 3 The first battery cell 21 includes a positive electrode ear 121 and a negative electrode ear 122, the second battery cell 22 includes a positive electrode ear 131 and a negative electrode ear 132, and the connecting piece 102 includes a positive electrode connecting piece 1021, a positive electrode connecting piece 1022 and a negative electrode connecting piece 1023, and a negative electrode connecting piece 1024. Figure 4 The pole 11 includes a positive pole 111 and a negative pole 112. The positive pole ear 121 of the first battery cell 21 and the positive pole ear 131 of the second battery cell 22 are connected to the same positive pole 111, and the negative pole ear 122 of the first battery cell 21 and the negative pole ear 132 of the second battery cell 22 are connected to the same negative pole.

[0032] Specifically, the positive electrode connecting sheet 1021 is suitable for connecting the positive electrode ear 121 and the positive electrode column 111, the positive electrode connecting sheet 1022 is suitable for connecting the positive electrode ear 131 and the positive electrode column 111, the negative electrode connecting sheet 1023 is suitable for connecting the negative electrode ear 122 and the negative electrode column 112, and the negative electrode connecting sheet 1024 is suitable for connecting the negative electrode ear 132 and the negative electrode column 112.

[0033] Reference Figure 5, the second lap surface S2 of the positive electrode connecting piece 1021 contacts the first lap surface S1 of the positive electrode column step 1011 to connect the positive electrode connecting piece 1021 and the positive electrode column 111. The second end surface S12 of the positive electrode connecting piece 1021 is connected to the positive electrode ear 121 of the first battery cell 21 to connect the positive electrode column 111 and the positive electrode ear 121 through the positive electrode connecting piece 1021. The structure of the positive electrode connecting piece 1022 connecting the positive electrode ear 131 in the second battery cell 22 and the positive electrode column 111 is the same as the structure of the positive electrode connecting piece 1021 connecting the positive electrode ear 121 in the first battery cell 21 and the positive electrode column 111, so it will not be described in detail here.

[0034] Further, the second lap joint surface S2 of the negative electrode connecting piece 1023 contacts the first lap joint surface S1 of the negative electrode column step 1012 to connect the negative electrode connecting piece 1023 and the negative electrode column 112. The second end surface S12 of the negative electrode connecting piece 1023 is connected to the negative electrode ear of the first battery cell 21 to connect the negative electrode column 112 and the negative electrode ear 122 through the negative electrode connecting piece 1023. The structure of the negative electrode connecting piece 1024 connecting the negative electrode ear 132 in the second battery cell 22 and the negative electrode column 112 is the same as the structure of the negative electrode connecting piece 1023 connecting the negative electrode ear 122 in the first battery cell 21 and the negative electrode column 112, so no further details are given here.

[0035] In this embodiment, the connection between the positive electrode connecting sheet 1021, the positive electrode ear 121 and the positive electrode column 111, the connection between the positive electrode connecting sheet 1022, the positive electrode ear 131 and the positive electrode column 111, the connection between the negative electrode connecting sheet 1023, the negative electrode ear 122 and the negative electrode column 112, and the connection between the negative electrode connecting sheet 1024, the negative electrode ear 132 and the negative electrode column 112 are all connected by laser welding.

[0036] On the other hand, the width of the pole step ranges from 1mm to 5mm, the thickness ranges from 1mm to 2mm, the height of the vertical surface is 0.5mm to 1mm, the width of the connecting piece step ranges from 1mm to 5mm, the thickness ranges from 1mm to 2mm, the height of the vertical surface is 0.5mm to 1mm, and the length of the first overlapping surface in contact with the second overlapping surface is 2mm to 3mm. The overall thickness of the lower end of the pole is 3mm to 5mm, and the overall thickness of the connecting piece is 3mm to 5mm.

[0037] The split connection structure provided in the present application can achieve electrical connection between the battery cell tab and the pole through a small-area connecting piece through the setting of the split structure, thereby reducing the area of ​​the connecting piece and saving the manufacturing cost of the connecting piece. In addition, the structure is simple and easy to manufacture, so that the flatness of the connecting piece is better, thereby improving the internal capacity of the battery from another aspect.

[0038] On the other hand, the present application also provides a battery cell cover plate, including a pole, a pole step is provided at the bottom of the pole, and the pole step includes a first overlapping surface, wherein the first overlapping surface is suitable for cooperating with the second overlapping surface of the connecting piece in the split connection structure (such as the above-mentioned connection structure 10) in any embodiment provided in the present application.

[0039] On the other hand, the present application also provides a power battery, such as the power battery 100 mentioned above, which includes one or more battery cell covers, one or more battery cells, and a split connection structure (such as the connection structure 10) in any embodiment provided in the present application. The present application also provides a power battery assembly, including multiple cascaded power batteries, such as the power battery 100 mentioned above.

[0040] The basic concepts have been described above. Obviously, for those skilled in the art, the above application disclosure is only an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0041] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0042] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more application embodiments, in the above description of the embodiments of this application, multiple features are sometimes merged into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0043] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0044] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A split connection structure, applicable to a power battery, wherein the power battery comprises one or more battery cell covers and one or more battery cells, wherein the battery cell covers comprise one or more poles, characterized in that: The split connection structure comprises: A pole step, located at the bottom of at least one of the poles, the pole step comprising a positive pole step, a negative pole step and a first overlap surface; A connecting piece, comprising a first end face and a second end face opposite to each other, wherein the connecting piece also comprises a connecting piece step arranged on the first end face, the connecting piece step comprises a second overlapping surface, the second overlapping surface is suitable for contacting with the first overlapping surface so that the first end face of the connecting piece is connected to the pole, and the second end face is suitable for connecting to the pole ear of the battery cell.

2. The split connection structure according to claim 1, characterized in that: The pole includes a positive pole, each of the battery cells includes a positive electrode ear, and the connecting piece includes a positive electrode connecting piece, and the positive electrode connecting piece is suitable for connecting the positive electrode ear and the positive pole, wherein, The second overlapping surface of the positive electrode connecting sheet contacts the first overlapping surface of the positive electrode post step to connect the positive electrode connecting sheet and the positive electrode post; and The second end surface of the positive electrode connecting sheet is connected to the positive electrode ear of the battery cell, so that the positive electrode column and the positive electrode ear are connected through the positive electrode connecting sheet.

3. The split connection structure according to claim 2, characterized in that: The pole includes a negative pole, each of the battery cells includes a negative electrode ear, and the connecting piece includes a negative electrode connecting piece, and the negative electrode connecting piece is suitable for connecting the negative electrode ear and the negative pole, wherein, The second overlapping surface of the negative electrode connecting piece contacts the first overlapping surface of the negative electrode post step to connect the negative electrode connecting piece and the negative electrode post; and The second end surface of the negative electrode connecting sheet is connected to the negative electrode ear of the battery cell, so that the negative electrode column and the negative electrode ear are connected through the negative electrode connecting sheet.

4. The split connection structure according to claim 3, characterized in that: The battery cell includes a first battery cell and a second battery cell adjacent to each other, the positive electrode tab of the first battery cell and the positive electrode tab of the second battery cell are connected to the same positive electrode pole, and the negative electrode tab of the first battery cell and the negative electrode tab of the second battery cell are connected to the same negative electrode pole.

5. The split connection structure according to claim 3, characterized in that: The positive electrode connecting piece is connected to the positive electrode ear and the positive electrode post by laser welding, and the negative electrode connecting piece is connected to the negative electrode ear and the negative electrode post by laser welding.

6. The split connection structure according to claim 1, characterized in that: The width range of the pole step is 1mm to 5mm, the thickness range of the pole step is 1mm to 2mm, the height of the vertical surface of the pole step is 0.5mm to 1mm, the width range of the connecting plate step is 1mm to 5mm, the thickness range of the connecting plate step is 1mm to 2mm, the height of the vertical surface of the connecting plate step is 0.5mm to 1mm, the contact length of the first overlapping surface and the second overlapping surface is 2mm to 3mm, the overall thickness of the lower end of the pole is 3mm to 5mm, and the overall thickness of the connecting plate is 3mm to 5mm.

7. A battery cell cover, characterized in that: include: A pole, wherein a pole step is provided at the bottom of the pole, and the pole step comprises a first overlapping surface, wherein the first overlapping surface is suitable for cooperating with the second overlapping surface of the connecting piece in the split connection structure according to any one of claims 1 to 6.

8. A power battery, characterized in that: include: One or more battery cell covers, and one or more battery cells, and a split connection structure as claimed in any one of claims 1 to 6.

9. A power battery assembly, characterized in that: A power battery as claimed in claim 8 comprising a plurality of cascade connections.

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