Single battery and battery module

Abstract

The utility model discloses a single battery and a battery module. The single battery provided by the utility model comprises a shell assembly and a plurality of battery cells, the shell assembly comprises a shell and partition plates, and the partition plates divide a plurality of accommodating cavities which are stacked in the thickness direction of the single battery in the shell; each battery cell comprises a battery cell main body and a tab connected with the battery cell main body, the battery cell main bodies are respectively positioned in the accommodating cavities, one ends of the tabs are positioned in the accommodating cavities and are connected with the battery cell main bodies, and the other ends of the tabs are exposed out of the shell; wherein the projections of the tabs in the thickness direction do not have an overlapping area. According to the single battery disclosed by the utility model, the thickness of the tab is relatively thin, and the folding operation of the top sealing edge can be relatively easily carried out after the top sealing is finished.

Description

Technical Field

[0001] The utility model relates to the field of lithium ion batteries, in particular to a single cell and a battery module. Background Art

[0002] With the development of science and technology, lithium-ion battery technology has been continuously improved, and people have higher demands for battery charging speed and energy density. In-line batteries are generally composed of two or more bare cells packed in the same packaging bag, which are completely separated by a partition in the middle. Such a structure can ensure that the battery cell can achieve high-rate charging while improving the energy density of the battery cell.

[0003] In the manufacturing process of internal series batteries, in order to ensure the sealing during the top seal, the width of the top seal edge must be greater than the set value. In order to increase the energy density of the battery, the top seal edge is often folded to avoid the top seal edge occupying the space in the length direction of the battery. Because the internal series battery has two or more battery cells, multiple battery cells need to be packaged in the same packaging bag. The overlapping setting of the pole ears of each battery cell results in a thick thickness, which is not conducive to the subsequent bending of the top seal edge. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a single battery, the thickness of the pole ear of the single battery is relatively thin, and the folding operation of the top sealing edge can be performed relatively easily after the top sealing is completed.

[0005] The utility model also provides a battery module having the above-mentioned single battery.

[0006] According to the first embodiment of the present invention, a single cell battery comprises:

[0007] A shell assembly, the shell assembly comprising a shell and a partition, the partition dividing the shell into a plurality of accommodating cavities stacked in a thickness direction of the single battery;

[0008] A plurality of battery cells, each of the battery cells comprising a battery cell body and a tab connected to the battery cell body, each of the battery cell bodies being respectively located in each of the accommodating cavities, one end of the tab being located in the accommodating cavity and connected to the battery cell body, and the other end being exposed from the housing;

[0009] Wherein, there is no overlapping area between the projections of the pole ears along the thickness direction.

[0010] The single cell battery according to the embodiment of the utility model has at least the following beneficial effects:

[0011] The tabs of the single cell of the present application are arranged in a staggered manner, so that after the top seal, the projections of the tabs along the thickness direction do not have overlapping areas, and thus the thickness of each tab is thin and relatively consistent. Therefore, after the top seal is completed, the folding operation of the top seal edge can be performed more easily. In addition, during the top seal, the thinner tab part is also conducive to the hot pressing during the top seal, so that the outer shell and the tab fit better, reducing the risk of leakage of the single cell.

[0012] According to some embodiments of the present invention, the tabs of each of the battery cells are disposed at the same end of the single battery.

[0013] According to some embodiments of the utility model, the single battery includes two battery cells, each of which includes a first pole lug and a second pole lug, and the two second pole lugs are adjacently arranged to form a pole lug assembly. In the pole lug assembly, the spacing between the two second pole lugs is smaller than the spacing from the pole lug assembly to any of the first pole lugs.

[0014] According to some embodiments of the utility model, the single battery includes N battery cells, N is a positive integer greater than or equal to 3, wherein two of the battery cells each include a first pole lug and a second pole lug, and the remaining battery cells include two second pole lugs, and the second pole lugs of two different battery cells are adjacently arranged to define a pole lug assembly, and the single battery includes N-1 pole lug assemblies, and in the same pole lug assembly, the spacing between two second pole lugs is smaller than the spacing from the pole lug assembly to any first pole lug and the minimum value of the spacing between two adjacent pole lug assemblies.

[0015] According to some embodiments of the present invention, the width of the second pole tab is smaller than the width of the first pole tab.

[0016] According to some embodiments of the present invention, the width of the pole tab assembly is not greater than the width of the first pole tab.

[0017] According to some embodiments of the present invention, the second pole tabs in the same pole tab assembly have opposite polarities.

[0018] According to some embodiments of the utility model, each of the pole tabs is wrapped with a pole tab glue, and the width of the pole tab glue is greater than the width of the pole tab.

[0019] According to some embodiments of the utility model, the single battery includes a tab assembly, and in the same tab assembly, the tab glues on two tabs are connected to each other.

[0020] According to some embodiments of the utility model, the single battery includes two battery cells, both of which include a first pole ear and a second pole ear, the two second pole ears are arranged adjacent to each other to form a pole ear assembly, and the pole ear glue wound around the first pole ear is set as the first pole ear glue, and the pole ear glue wound around the second pole ear is set as the second pole ear glue;

[0021] Among them, the thickness a of the first pole ear glue, the width b of the first pole ear, the thickness c of the second pole ear glue, the width d of the second pole ear, and the distance i between two second pole ear glues in the same pole ear assembly have the following relationship: d+2c+i / 2<b+2a.

[0022] According to the second aspect of the present invention, the battery module comprises:

[0023] A circuit board, wherein the circuit board comprises a power supply module and a detection module;

[0024] As in any one of the above embodiments, the single battery is electrically connected to the power supply module and the detection module respectively.

[0025] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0027] Figure 1 It is a schematic diagram of the structure of a single cell of the utility model;

[0028] Figure 2 For composition Figure 1 A schematic diagram of the structure of each cell of the single battery shown;

[0029] Figure 3 This is a schematic diagram of the structure of a single cell in another embodiment of the utility model;

[0030] Figure 4 For composition Figure 3 A schematic diagram of the structure of each cell of the single battery shown;

[0031] Figure 5 It is an enlarged schematic diagram of the top of the single cell of the utility model.

[0032] Reference numerals:

[0033] Single battery 10; battery cell 20; first pole tab 100; first pole tab glue 150; second pole tab 200; second pole tab glue 250; pole tab assembly 300. DETAILED DESCRIPTION

[0034] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0035] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0036] In the description of the present utility model, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used to distinguish the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0037] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0038] In the description of the utility model, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0039] With the development of science and technology, lithium-ion battery technology has been continuously improved, and people have higher demands for battery charging speed and energy density. In-line batteries are generally composed of two or more bare cells packed in the same packaging bag, which are completely separated by a partition in the middle. Such a structure can ensure that the battery cell can achieve high-rate charging while improving the energy density of the battery cell.

[0040] In the manufacturing process of the inner-series battery, in order to ensure the sealing during the top seal, it is necessary to ensure that the width of the top seal is greater than the set value. In order to increase the energy density of the battery, the top seal of the battery cell is often folded and assembled accordingly at the pack end (that is, the assembly end) of the battery cell to reduce the space occupied by the top seal in the length direction of the battery. Since the inner-series battery is provided with two or more battery cells 20, multiple battery cells 20 need to be packaged in the same packaging bag. The overlapping arrangement of the pole ears of each battery cell 20 results in a thick thickness, which is not conducive to the subsequent bending process of the top seal. In addition, since the thickness of the overlapping arrangement of the pole ears is relatively thick, it is not conducive to the fitting of the aluminum-plastic film and the pole ears during the top seal process, resulting in a greater risk of leakage of the single battery 10.

[0041] In order to solve the above problems, a single cell 10 is proposed in the present application. The single cell 10 includes a shell assembly and a plurality of battery cells 20. The shell assembly includes a shell and a partition. The shell can be an aluminum-plastic film, a steel shell, an aluminum shell, etc. It is an external shell covering the battery cell 20 and plays the role of dust prevention and liquid leakage prevention. The partition divides a plurality of accommodating cavities in the shell. Each accommodating cavity is stacked along the thickness direction of the single cell 10. A battery cell 20 is arranged in each accommodating cavity. The battery cell 20 includes a battery cell body and a pole ear. The battery cell body can be formed by winding pole sheets or by stacking sheets. Each battery cell body is located in each accommodating cavity. Among them, the battery cell body is the main energy storage part of the battery, which is usually composed of active substances, electrolytes and current collectors. The active substances are responsible for electrochemical reactions to generate current, the electrolyte plays the role of transmitting ions, and the current collector is the supporting structure of the battery cell body, which is responsible for collecting and transmitting current. The tab is a portion extending from the battery body, one end of which is connected to the pole piece of the battery body, and the other end is exposed from the casing for leading out the current generating circuit.

[0042] In this embodiment, during the assembly process of the single battery 10, after each battery cell 20 is placed in the accommodating cavity, the pole ears of each battery cell 20 are staggered. It should be noted that before the top seal, along the thickness direction of the single battery cell 10, the pole ears are on different planes. During the top seal, the pressing parts of the top seal mechanism are closed along the thickness direction of the single battery cell 10, and the outer shell is hot-pressed to form a top seal edge. The pole ears are pressed on the same plane, which is perpendicular to the thickness direction of the single battery cell 10. It should be noted that the thickness direction of the single battery cell 10 is perpendicular to the thickness direction of the single battery cell 10. Figure 1 Paper orientation shown.

[0043] Since the pole ears are staggered, there is no overlapping area in the projection of the pole ears along the thickness direction after the top seal. It should be explained that the pole ears mentioned here refer to both the positive pole ears and the negative pole ears on the same battery cell 20 and the positive pole ears and the negative pole ears on different battery cells 20. Furthermore, the thickness of each pole ear is relatively thin and the thickness is relatively consistent. Therefore, the folding operation of the top seal edge can be performed more easily after the top seal is completed. In addition, during the top seal, the thinner pole ear part is also conducive to the hot pressing during the top seal, so that the outer shell and the pole ear have better fit, reducing the risk of leakage of the single battery 10.

[0044] In some embodiments, the tabs are arranged at different ends of each battery cell 20, or each battery cell 20 is placed in different postures so that the tabs are located at different ends of the single battery 10, so that there is no overlapping area in the projection of each tab along the thickness direction. In other embodiments, the tabs of each battery cell 20 are arranged at the same end of the single battery 10, so that each tab is staggered along the thickness direction of the battery cell 20, so that there is no overlapping area.

[0045] In the prior art, the top of the battery usually leads to two tabs, a positive tab and a negative tab. In this application, Figure 1 and Figure 2 As shown, Figure 2 The two cells 20 shown in FIG. 1 are assembled to form a Figure 1 The single cell 10 shown. Take the single cell 10 including two battery cells 20 as an example, each battery cell 20 includes a positive pole ear and a negative pole ear. Since the pole ears of each battery cell 20 are staggered, after the top seal, the top seal edge of the single cell 10 leads to two positive pole ears and two negative pole ears, a total of four pole ears. The single cell 10 of the present application needs to be connected to the circuit board to realize the external series connection of the battery cell 20 and the on-off control of the circuit. In order to reduce the number of welding points between the single cell 10 and the circuit board and improve the welding efficiency, the present application also makes improvements to the pole ears of the single cell 10.

[0046] Specifically, Figure 2 As shown, each battery cell 20 includes a first pole tab 100 and a second pole tab 200. It is understandable that the first pole tab 100 can be a positive pole tab or a negative pole tab, and the first pole tab 100 and the second pole tab 200 on the same battery cell 20 have opposite polarities. Figure 1 As shown, on the single battery 10, each second pole tab 200 is disposed adjacent to each other to define a pole tab assembly 300. It should be noted that in the pole tab assembly 300, the distance between two second pole tabs 200 is smaller than the distance between the pole tab assembly 300 and any first pole tab 100.

[0047] like Figure 1The single battery 10 shown includes two battery cells 20, each of which includes a first pole tab 100 and a second pole tab 200, wherein the two second pole tabs 200 are arranged adjacent to each other to form a pole tab assembly 300, and the two second pole tabs 200 can be welded to the same welding point of the circuit board, and the two first pole tabs 100 are respectively welded to two welding points of the circuit board, thereby, Figure 1 The circuit board matched with the single battery 10 shown only needs to be provided with three welding points.

[0048] It is understandable that the positions of the tab assembly 300 and the two first tabs 100 can be interchanged at will, such as Figure 1 The tab assembly 300 is shown as being located in the middle, and the two first tabs 100 are respectively located on both sides of the tab assembly 300 ; alternatively, the tab assembly 300 may also be located on the left or right side of the two first tabs 100 .

[0049] Further, such as Figure 1 and Figure 2 As shown, the width of the second pole tab 200 is smaller than the width of the first pole tab 100, thereby reducing the width of the pole tab assembly 300, so that the corresponding solder joint area on the circuit board is smaller, which is conducive to improving the space utilization on the circuit board. Further, the width of the pole tab assembly 300 is not greater than the width of the first pole tab 100, so that the solder joint corresponding to the pole tab assembly 300 is the same size as the solder joint corresponding to the first pole tab 100, so that there is no need to make a differentiated design for the solder joint of the pole tab assembly 300.

[0050] It should be understood that the polarities of the two second pole tabs 200 in the same pole tab assembly 300 can be opposite or the same. If the polarities of the two second pole tabs 200 are opposite, after being welded to the same welding point, the two battery cells 20 are externally connected in series through the circuit board, so that the single battery 10 can obtain a higher voltage value. Alternatively, if the polarities of the two second pole tabs 200 are the same, after being welded to the same welding point, the two battery cells 20 are externally connected in parallel through the circuit board, so that the single battery 10 can obtain a higher current value.

[0051] It is understandable that the single battery 10 may also include N battery cells 20, where N is a positive integer greater than or equal to 3, that is, the single battery 10 may also include three battery cells 20, four battery cells 20, etc. When the number of battery cells 20 exceeds two, two of the battery cells 20 include a first pole tab 100 and a second pole tab 200, and the remaining battery cells 20 include two second pole tabs 200, wherein the second pole tabs 200 of two different battery cells 20 are adjacently arranged to form a pole tab assembly 300, and one pole tab assembly 300 corresponds to one solder joint on the circuit board. A total of N-1 pole tab assemblies 300 are arranged on the single battery 10, that is, as Figure 3 and Figure 4As shown, when the single battery 10 includes three battery cells 20, there are two tab assemblies 300 on the top sealing edge of the single battery 10; when the single battery 10 includes four battery cells 20, there are three tab assemblies 300 on the top sealing edge of the single battery 10, and so on. It should be noted that in the same tab assembly 300, the spacing between two second tabs 200 is smaller than the spacing between the tab assembly 300 and any first tab 100, and the spacing between the two second tabs 200 is smaller than the spacing between two adjacent tab assemblies 300.

[0052] In a single battery 10 having three or more battery cells 20, the width of the second pole tab 200 is smaller than the width of the first pole tab 100. Therefore, in the manufacturing process of the battery cell 20, it is necessary to manufacture two battery cells 20 having one wide pole tab (first pole tab 100) and one narrow pole tab (second pole tab 200), and at least one battery cell 20 having two narrow pole tabs (second pole tabs 200). Figure 3 and Figure 4 For example, the single cell 10 includes three battery cells 20, wherein the first battery cell 20 has a wide positive electrode tab and a narrow negative electrode tab, the second battery cell 20 has a narrow positive electrode tab and a narrow negative electrode tab, and the third battery cell 20 has a narrow positive electrode tab and a wide negative electrode tab, so that the narrow negative electrode tab of the first battery cell 20 and the narrow positive electrode tab of the second battery cell 20 are adjacent to form a first tab assembly 300 after top sealing, and the narrow negative electrode tab of the second battery cell 20 and the narrow positive electrode tab of the third battery cell 20 are adjacent to form a second tab assembly 300 after top sealing. Thus, the top sealing edge of the single cell 10 has a wide positive electrode tab, two tab assemblies 300 and a wide negative electrode tab, wherein the wide positive electrode tab and the wide negative electrode tab can be used to connect the charge and discharge solder joints of the circuit board, and the two tab assemblies 300 can be used to connect the detection solder joints of the circuit board and realize external series connection.

[0053] Similarly, in a single battery 10 having three or more battery cells 20, the width of the tab assembly 300 is not greater than the width of the first tab 100, and preferably, the width of the tab assembly 300 is equal to the width of the first tab 100. It should be noted that the width of the tab assembly 300 is not equal to the sum of the widths of the two second tabs 200, because the tabs are often coated with tab glue, and thus, there is often a gap between the two second tabs 200.

[0054] It should be noted that in a single battery 10 having three or more battery cells 20 , the polarities of the second tabs 200 in the same tab assembly 300 should remain opposite.

[0055] It should be explained that each tab is wound with tab glue. Since the tab glue has a certain thickness, when the tab glue is attached to the tab, the width of the tab glue along the width direction of the tab is greater than the width of the tab. Figure 5 As shown, the first pole ear 100 is wound with a first pole ear glue 150, and the second pole ear 200 is wound with a second pole ear glue 250. The thickness of the first pole ear glue 150 is set to a, the width of the first pole ear 100 is set to b, the thickness of the second pole ear glue 250 is set to c, the width of the second pole ear 200 is set to d, and the spacing between the two second pole ear glues 250 in the same pole ear assembly 300 is i. The second pole ear 200 and the first pole ear 100 have the following relationship: d+2c+i / 2<b+2a. At this time, compared with the solder joint arrangement space of the conventional internal series 4-pole ear battery, the solder joint arrangement space on the pack board (i.e., the assembly board) of the battery cell of the present application is smaller, thereby being able to leave more arrangement space for other electronic components to save material costs. Furthermore, the following relationship exists between the tab assembly 300 and the first tab 100: 2(d+2c+i / 2)≤b+2a. At this time, compared with the solder joint arrangement space of the conventional internal 4-tab battery, the solder joint arrangement space on the battery pack board of the present application is further reduced, which is equivalent to the solder joint arrangement space size of the conventional internal 3-tab battery, or smaller than the solder joint arrangement space of the conventional internal 3-tab battery, thereby reducing the risk of top seal leakage (overlapping tab top edge packaging is prone to poor packaging due to its thick thickness). Further, the spacing i between the two second tab glues 250 in the same tab assembly 300 is 0, so that the second tab glues 250 of the two second tabs 200 are connected and arranged. At this time, the width of the tab assembly 300 is the smallest, and the solder joint arrangement space on the battery pack board is further reduced.

[0056] The embodiment of the second aspect of the present application also includes a battery module, which includes a circuit board and a single cell 10 mentioned in any of the above embodiments, and a power supply module and a detection module are provided on the circuit board, and the single cell 10 is electrically connected to the power supply module and the detection module respectively. Specifically, the two first pole ears 100 of the single cell 10 are electrically connected to the power supply module as positive and negative poles respectively to realize the charging and discharging of the single cell 10. The pole ear assembly 300 of the single cell 10 is electrically connected to the detection module to realize the electrical parameter detection of the single cell 10. It can be understood that the first pole ear 100 is used for passing large currents of charging and discharging due to its wide width to reduce the risk of heating and melting of the pole ear. The second pole ear 200 is narrow in width and is used to connect the test circuit.

[0057] The embodiments of the utility model are described in detail above in conjunction with the accompanying drawings, but the utility model is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the utility model. In addition, the embodiments of the utility model and the features in the embodiments can be combined with each other without conflict.

Claims

1. A single cell, characterized in that: include: A shell assembly, the shell assembly comprising a shell and a partition, the partition dividing the shell into a plurality of accommodating cavities stacked in a thickness direction of the single battery; A plurality of battery cells, each of the battery cells comprising a battery cell body and a tab connected to the battery cell body, each of the battery cell bodies being respectively located in each of the accommodating cavities, one end of the tab being located in the accommodating cavity and connected to the battery cell body, and the other end being exposed from the housing; Wherein, there is no overlapping area between the projections of the pole ears along the thickness direction.

2. The single cell according to claim 1, characterized in that: The tabs of each battery cell are arranged at the same end of the single battery.

3. The single cell according to claim 1, characterized in that: The single battery includes two battery cells, each of which includes a first pole tab and a second pole tab. The two second pole tabs are adjacently arranged to form a pole tab assembly. In the pole tab assembly, the distance between the two second pole tabs is smaller than the distance from the pole tab assembly to any of the first pole tabs.

4. The single cell according to claim 1, characterized in that: The single battery includes N battery cells, N is a positive integer greater than or equal to 3, wherein two of the battery cells each include a first pole lug and a second pole lug, and the remaining battery cells include two second pole lugs, and the second pole lugs of two different battery cells are adjacently arranged to define a pole lug assembly, and the single battery includes N-1 pole lug assemblies, and in the same pole lug assembly, the spacing between two second pole lugs is smaller than the spacing from the pole lug assembly to any first pole lug and the minimum value of the spacing between two adjacent pole lug assemblies.

5. The single cell according to claim 3 or 4, characterized in that: The width of the second electrode tab is smaller than the width of the first electrode tab.

6. The single cell according to claim 5, characterized in that: The width of the tab assembly is not greater than the width of the first tab.

7. The single cell according to claim 3 or 4, characterized in that: The polarities of the second pole tabs in the same pole tab assembly are opposite.

8. The single cell according to claim 1, characterized in that: Each of the pole tabs is wound with a pole tab glue, and the width of the pole tab glue is greater than the width of the pole tab.

9. The single cell according to claim 8, characterized in that: The single cell includes a tab assembly, and in the same tab assembly, the tab glues on two tabs are connected to each other.

10. The single cell according to claim 8, characterized in that: The single battery comprises two cells, each of which comprises a first pole tab and a second pole tab, the two second pole tabs are arranged adjacent to each other to form a pole tab assembly, the pole tab glue wound around the first pole tab is set as the first pole tab glue, and the pole tab glue wound around the second pole tab is set as the second pole tab glue; Among them, the thickness a of the first pole ear glue, the width b of the first pole ear, the thickness c of the second pole ear glue, the width d of the second pole ear, and the distance i between two second pole ear glues in the same pole ear assembly have the following relationship: d+2c+i / 2<b+2a.

11. A battery module, characterized in that: include: A circuit board, wherein the circuit board comprises a power supply module and a detection module; The single cell according to any one of claims 1 to 10, wherein the single cell is electrically connected to the power supply module and the detection module respectively.

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