Battery cell

Abstract

The utility model relates to battery technology field provides a kind of battery monomer, it includes shell component and the electric core housed in shell component, electric core includes current collector, main tab and at least one auxiliary tab are welded with interval on current collector, main tab is provided with the transition part for being connected with auxiliary tab, the end of main tab away from current collector and the end of auxiliary tab away from current collector are welded with shell component. Main tab and auxiliary tab are welded with current collector separately, even if main tab breaks at its connection with current collector, electric core can output or input current by auxiliary tab and transition part. For example, the current in electric core sequentially passes through auxiliary tab and transition part and enters main tab. In this way, the welding reliability of battery monomer can be effectively improved, and the service life of the battery monomer can be effectively improved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery cell. Background Technology

[0002] Generally, an electrode assembly includes a positive electrode, a separator, and a negative electrode. The positive electrode, separator, and negative electrode are formed into the aforementioned electrode assembly through a stacking process or a winding process. Both the positive and negative electrode include a current collector and a tab. Typically, the current collector includes a coating area and an empty foil area. The coating area is coated with an active material layer, and the tab is soldered to the empty foil area. The tab is used to connect with external structural components.

[0003] Chinese patent application CN201822215767.2 discloses a cylindrical lithium-ion battery positive electrode tab welding structure, which includes a positive electrode tab plate, a main electrode tab welded to the center of the positive electrode tab plate, and auxiliary electrode tabs evenly distributed on both sides of the main electrode tab, with a number of auxiliary electrode tabs. The main electrode tab and auxiliary electrode tabs are arranged at intervals, and the auxiliary electrode tabs are also arranged at intervals. During welding, each auxiliary electrode tab is ultrasonically welded to the main electrode tab, and the main electrode tab is then individually welded to the cap. However, the total thickness of the main electrode tab and the auxiliary electrode tabs is relatively large, making it prone to incomplete welds during welding. Furthermore, in existing battery cells without auxiliary electrode tab structures, the welding of a single electrode tab structure to the current collector or casing assembly also suffers from incomplete welds or over-welds due to various reasons. This leads to easy breakage at the weld joints between the electrode tab and the current collector, and between the electrode tab and the casing assembly, resulting in poor welding reliability of the battery cell and rendering it unusable, significantly shortening its lifespan. Utility Model Content

[0004] The purpose of this invention is to provide a battery cell that addresses the technical problem of the low lifespan of existing battery cells.

[0005] This application provides a battery cell, including a housing assembly and a battery cell housed within the housing assembly. The battery cell includes a current collector, on which a main electrode and at least one secondary electrode are welded at intervals. The main electrode has a transition portion for connecting with the secondary electrode. The end of the main electrode away from the current collector and the end of the secondary electrode away from the current collector are both welded to the housing assembly.

[0006] The beneficial effects of the battery cell provided by this utility model are:

[0007] First, the main tab and the secondary tab are welded separately to the current collector. Even if the main tab breaks at its connection with the current collector, the cell can still output or input current through the secondary tab and the transition section. For example, the current in the cell sequentially passes through the secondary tab and the transition section to enter the main tab. This effectively improves the welding reliability of the battery cell and extends its service life. Furthermore, in addition to welding the main tab to the casing assembly, the secondary tab is also welded to the casing assembly. This means that even if the main tab breaks at its connection with the casing assembly, the cell can still output or input current through the secondary tab, greatly reducing the possibility of problems such as poor welding during the main tab welding process, further improving the welding reliability of the battery cell, and thus further extending its service life.

[0008] Secondly, the secondary electrode provided in this invention can also play a role in current shunting and balancing when the battery cell is transmitting a large current.

[0009] Furthermore, the length of the solder joint can be effectively controlled within the individual battery cells. This can be understood as follows: with the same tab length, within this individual battery cell, due to gaps between the connection points of the main tab and the current collector, and between the main tab and the casing assembly, and between the secondary tab and the casing assembly, the welding equipment does not need to perform welding operations within these gaps. This effectively shortens the solder joint length, thereby reducing heat accumulation during welding and improving the overall sealing performance of the battery cell.

[0010] Optionally, the current collector has an empty foil area, and both the main electrode and the secondary electrode are welded to the empty foil area. A gap is provided between the connection between the main electrode and the empty foil area and between the connection between the secondary electrode and the empty foil area.

[0011] Optionally, multiple secondary electrodes are distributed at both ends of the main electrode along its length extension direction.

[0012] Optionally, multiple secondary electrodes are distributed at the same end along the length extension direction of the primary electrode.

[0013] Optionally, multiple secondary electrodes located at one end of the main electrode extension direction are connected in sequence and then connected to the transition section.

[0014] Optionally, the housing assembly includes a housing and terminals mounted on the housing, the battery cell is installed inside the housing, and the main and secondary terminals are connected to the housing, or the main and secondary terminals are connected to the terminals.

[0015] Optionally, both the main electrode and the secondary electrode are provided with electrode adhesive.

[0016] Optionally, the transition section is located inside the cell.

[0017] Optionally, two adjacent secondary electrodes are connected by a connecting part located inside the battery cell.

[0018] Optionally, the battery cell is a laminated battery cell or a wound battery cell. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the battery cell provided in an embodiment of this utility model;

[0021] Figure 2 Another structural schematic diagram of the battery cell provided in this embodiment of the utility model;

[0022] Figure 3 An exploded view of the battery cell provided in an embodiment of this utility model;

[0023] Figure 4 Another exploded view of the battery cell provided in this embodiment of the utility model;

[0024] Figure 5 Another exploded view of the battery cell provided in this embodiment of the utility model;

[0025] Figure 6 Another exploded view of the battery cell provided in this embodiment of the utility model.

[0026] The following are the labeling elements in the figure:

[0027] 100. Battery cell; 10. Main tab; 20. Secondary tab;

[0028] 30. Current collector; 40. Tab adhesive; 50. Transition section;

[0029] 60. Connecting part; 11. First soldering area; 12. Second soldering area;

[0030] 21. Third soldering area; 22. Fourth soldering area; 31. Empty foil area;

[0031] 311, Fifth soldering area; 312, Sixth soldering area. Detailed Implementation

[0032] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0033] Throughout this specification, references to "one embodiment" or "embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of this application. Therefore, the phrases "in another embodiment of this application," "in one embodiment," or "in some embodiments" appear in various places throughout the specification, and not all refer to the same embodiment. Furthermore, in one or more embodiments, particular features, structures, or characteristics may be combined in any suitable manner.

[0034] In the description of this utility model, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0036] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0037] Please refer to Figures 1 to 6 The battery cell in the embodiments of this utility model will now be described.

[0038] Please refer to Figure 1 The X-axis is the length direction of the main electrode 10, the Y-axis is the width direction of the main electrode 10, and the Z-axis is the thickness direction of the main electrode 10.

[0039] Please refer to Figures 1 to 6 This application provides a battery cell comprising a casing assembly (not shown) and a battery cell 100 housed within the casing assembly. The battery cell 100 includes a current collector 30, on which a main electrode tab 10 and at least one secondary electrode tab 20 are welded at intervals. The main electrode tab 10 is provided with a transition portion 50 for connection with the secondary electrode tab 20. Both the end of the main electrode tab 10 away from the current collector 30 and the end of the secondary electrode tab 20 away from the current collector 30 are welded to the casing assembly. A gap is provided between the connection point of the main electrode tab 10 and the casing assembly and the connection point of the secondary electrode tab 20 and the casing assembly.

[0040] First, the main tab 10 and the secondary tab 20 are individually welded to the current collector 30. Even if the main tab 10 breaks at its connection with the current collector 30, the cell 100 can still output or input current through the secondary tab 20 and the transition section 50. For example, the current in the cell 100 sequentially passes through the secondary tab 20 and the transition section 50 before entering the main tab 10. This effectively improves the welding reliability of the battery cell and extends its service life. Furthermore, in addition to the main tab 10 being welded to the casing assembly, the secondary tab 20 is also welded to the casing assembly. Therefore, even if the main tab 10 breaks at its connection with the casing assembly, the cell 100 can still output or input current through the secondary tab 20, greatly reducing the possibility of incomplete welding during the main tab 10 welding process, further improving the welding reliability of the battery cell, and thus further extending its service life.

[0041] Secondly, the secondary tab 20 provided in this invention can also play a role in current balancing when the battery cell 100 is transmitting a large current.

[0042] Furthermore, the length of the solder joint can be effectively controlled within this battery cell. This can be understood as follows: with the same tab length, in this battery cell, because there are gaps between the connection points of the main tab 10 and the current collector 30, and between the secondary tab 20 and the current collector 30, and between the connection points of the main tab 10 and the casing assembly, and between the secondary tab 20 and the casing assembly, the welding equipment does not need to perform welding operations within these gaps during welding. This effectively shortens the solder joint length, thereby reducing heat accumulation during welding and improving the overall sealing effect of the battery cell.

[0043] In another embodiment of this application, please refer to Figures 1 to 6The current collector 30 has an empty foil area 31. Both the main electrode tab 10 and the secondary electrode tab 20 are welded to the empty foil area 31. A gap is provided between the connection point of the main electrode tab 10 and the empty foil area 31 and the connection point of the secondary electrode tab 20 and the empty foil area 31. It can be understood that, in addition to the empty foil area 31, the current collector 30 also has a coating area. Typically, the current collector 30 is a metal foil sheet. The coating area on the current collector 30 is used to carry the active material. When the current collector 30 is used to carry the positive electrode active material, it is a positive electrode current collector. When the current collector 30 is used to carry the negative electrode active material, it is a negative electrode current collector. The empty foil area 31 refers to the area on the current collector 30 where no slurry is coated.

[0044] For clarity, please refer to the diagram. Figures 3 to 6 The main electrode 10 has a first soldering area 11 and a second soldering area 12, the secondary electrode 20 has a third soldering area 21 and a fourth soldering area 22, and the empty foil area 31 has a fifth soldering area 311 and a sixth soldering area 312 arranged at intervals. The first soldering area 11 of the main electrode 10 corresponds to the fifth soldering area 311 of the empty foil area 31, and the third soldering area 21 of the secondary electrode 20 corresponds to the sixth soldering area 312 of the empty foil area 31. That is, the main electrode 10 and the empty foil area 31 are connected at the first soldering area 11 and the fifth soldering area 311, and the secondary electrode 20 and the empty foil area 31 are connected at the third soldering area 21 and the sixth soldering area 312. The main electrode 10 is connected to the housing assembly at the second soldering area 12, and the secondary electrode 20 is connected to the housing assembly at the fourth soldering area 22.

[0045] The secondary electrode 20 can be welded to the main electrode 10 or it can be integrally formed with the main electrode 10; this is not limited here.

[0046] The battery cells provided in this application can be blade battery cells, pouch battery cells, and prismatic battery cells, etc.

[0047] In another embodiment of this application, please refer to Figure 3 and Figure 4 The number of secondary electrodes 20 is multiple, and the multiple secondary electrodes 20 are respectively distributed at both ends of the main electrode 10 along its length extension direction. As an example, in one embodiment, the number of secondary electrodes 20 is two, and the two secondary electrodes 20 are respectively located at both ends of the main electrode 10 along its length direction.

[0048] It should be noted that in this application, "multiple" refers to two or more (including two).

[0049] In another embodiment of this application, please refer to Figure 5 and Figure 6The number of secondary electrodes 20 is multiple, and the multiple secondary electrodes 20 are distributed at the same end in the length extension direction of the main electrode 10. As an example, in one embodiment, the number of secondary electrodes 20 is two, and both secondary electrodes 20 are located at one end in the length direction of the main electrode 10.

[0050] In another embodiment of this application, please refer to Figure 5 and Figure 6 Multiple secondary electrodes 20 located at one end of the main electrode 10 along its length are connected in sequence and then connected to the transition portion 50. Specifically, multiple secondary electrodes 20 are connected in sequence along the length of the main electrode 10, adjacent secondary electrodes 20 are connected by a connecting portion 60, and the secondary electrode 20 closest to the main electrode 10 is connected to the main electrode 10 through the transition portion 50.

[0051] In another embodiment of this application, the housing assembly includes a housing and a terminal post mounted on the housing, the battery cell 100 is mounted inside the housing, and the main electrode 10 and its secondary electrode 20 are connected to the housing.

[0052] Of course, in some other embodiments, the main electrode 10 and the secondary electrode 20 thereon may also be connected to the electrode post.

[0053] Furthermore, the housing includes a top cover and a bottom cover. The bottom cover has an open mounting cavity at one end. The top cover is sealed to the bottom cover and seals the mounting cavity. The battery cell 100 is housed within the mounting cavity. The main electrode 10 and its auxiliary electrode 20 can be connected to either the top cover or the bottom cover.

[0054] In another embodiment of this application, please refer to Figure 3 and Figure 5 Both the main tab 10 and the secondary tab 20 are provided with tab adhesive 40 to facilitate the encapsulation and molding of the battery cell 100. At this time, the battery cell 100 is a soft-pack battery cell 100, and the transition portion 50 and the connecting portion 60 are both located inside the battery cell 100. The secondary tab 20, located outside the battery cell 100, is easily bent and broken by external working conditions and environmental influences. However, since part of the secondary tab 20 is located inside the battery cell 100, it can still be connected to the main tab 10 through the transition portion 50, allowing the secondary tab 20 to still play a certain role and greatly improving its practicality.

[0055] In another embodiment of this application, please refer to Figures 1 to 6 The length of the main tab 10 is greater than the length of the secondary tab 20. The main tab 10 is the primary tab for input or output current, while the secondary tab 20 is a secondary tab. The main function of the secondary tab 20 is to ensure that the battery cell can still operate when the main tab 10 breaks at its connection with the housing assembly or at its connection with the empty foil area 31. Therefore, configuring the length of the main tab 10 to be greater than the length of the secondary tab 20 ensures the overcurrent capacity of the battery cell.

[0056] In another embodiment of this application, the materials of the current collector 30, the main electrode 10, and the secondary electrode 20 are all the same. This arrangement facilitates welding between the three components while improving current carrying capacity.

[0057] In another embodiment of this application, please refer to Figure 1 and Figure 2 There are multiple current collectors 30, which are stacked along the thickness direction of the cell 100. The main electrode 10 and the secondary electrode 20 are both located in the empty foil area 31 located at the top or bottom layer. The thickness direction of the cell is parallel to the thickness direction of the main electrode 10.

[0058] In another embodiment of this application, please refer to Figure 2 The current collector 30 has multiple empty foil areas 31, which are arranged at intervals. The total number of empty foil areas 31 on the current collector 30 is A, and the total number of main electrode tabs 10 and auxiliary electrode tabs 20 is B, satisfying the relationship A = B. In this embodiment, each main electrode tab 10 corresponds to one empty foil area 31, and each auxiliary electrode tab 20 corresponds to one empty foil area 31. With this arrangement, the heat transferred from one empty foil area 31 to another can be reduced during welding, thereby improving the overall welding quality and welding reliability.

[0059] The battery cell 100 in this application is a laminated battery cell or a wound battery cell.

[0060] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A single battery cell, characterized in that: The device includes a housing assembly and a battery cell (100) housed within the housing assembly. The battery cell (100) includes a current collector (30) on which a main electrode (10) and at least one secondary electrode (20) are welded at intervals. The main electrode (10) is provided with a transition portion (50) for connection with the secondary electrode (20). Both the end of the main electrode (10) away from the current collector (30) and the end of the secondary electrode (20) away from the current collector (30) are welded to the housing assembly.

2. The battery cell according to claim 1, characterized in that: The current collector (30) has an empty foil area (31). The main electrode (10) and the secondary electrode (20) are both welded to the empty foil area (31). A gap is provided between the connection between the main electrode (10) and the empty foil area (31) and the connection between the secondary electrode (20) and the empty foil area (31).

3. The battery cell according to claim 1, characterized in that: Multiple secondary electrodes (20) are respectively distributed at both ends of the main electrode (10) along its length extension direction.

4. The battery cell according to claim 1, characterized in that: Multiple secondary electrodes (20) are distributed at the same end along the length extension direction of the main electrode (10).

5. The battery cell according to claim 1, characterized in that: Multiple secondary electrodes (20) located at one end of the length extension direction of the main electrode (10) are connected in sequence and then connected to the transition part (50).

6. The battery cell according to any one of claims 1 to 5, characterized in that: The housing assembly includes a housing and a terminal post mounted on the housing. The battery cell (100) is mounted inside the housing. The main electrode (10) and the secondary electrode (20) are connected to the housing, or the main electrode (10) and the secondary electrode (20) are connected to the terminal post.

7. The battery cell according to any one of claims 1 to 5, characterized in that: Both the main electrode (10) and the secondary electrode (20) are provided with electrode adhesive (40).

8. The battery cell according to claim 7, characterized in that: The transition section (50) is located inside the battery cell (100).

9. The battery cell according to claim 7, characterized in that: The two adjacent secondary tabs (20) are connected by a connecting part (60) located inside the battery cell (100).

10. The battery cell according to claim 7, characterized in that: The battery cell (100) is a laminated battery cell (100) or a wound battery cell (100).

Images