Winding type battery
By using a design with four spaced-apart first tabs and multiple interconnected second tabs, the balance between charging rate and volumetric energy density in existing wound batteries is solved, achieving a battery design with high charging rate and high volumetric energy density.
Patent Information
- Application Number
- CN202422878722.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2025-11-11
- Estimated Expiration
- 2034-11-25
AI Technical Summary
Existing wound batteries struggle to balance charging rate and volumetric energy density. Single-tab wound cells have low charging rates and are prone to lithium plating, while multi-tab wound cells have low volumetric energy density due to the space occupied by the tabs.
It adopts a four-first electrode design, with the first electrodes arranged at intervals and directly led out, eliminating the need for overlapping areas. Combined with multiple second electrodes that are interconnected, the current path is shortened and the electrode layout is optimized to improve the charging rate and volumetric energy density.
It achieves a balance between high charging rate and high volumetric energy density, reduces the risk of lithium plating, and improves battery safety and space utilization.
Smart Images
Figure CN223539641U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to batteries, and more particularly to a wound battery. Background Technology
[0002] Existing wound batteries include a casing and wound cells inside the casing. The wound cells are formed by winding electrode assemblies, which include a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes. Some existing single-tab wound cells have one positive tab and one negative tab at the head. While these wound cells have a high volumetric energy density, their charging rate is low, and current concentration near the tabs can easily lead to lithium plating. Other existing multi-tab wound cells have multiple tabs on both sides of each electrode. Tabs of the same electrode on the same side are brought together, overlapped, and bent before being connected to the electrode leads. While this type of wound cell can improve the charging rate, the tabs need to be longer because they need to be brought together, overlapped, and bent before welding the electrode leads. The area where the tabs are brought together, overlapped, and bent occupies a significant portion of the casing cavity, resulting in a lower volumetric energy density. Utility Model Content
[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a wound battery that can have a high charging rate and volumetric energy density.
[0004] A wound battery according to an embodiment of the present invention includes a wound cell and a casing. The wound cell is formed by winding an electrode assembly, the electrode assembly including two electrodes and a separator disposed between the two electrodes. Each electrode has two first tabs on one side along its length direction, the two first tabs being spaced apart along the length direction of the electrode. Each electrode has multiple second tabs on the other side along its length direction, all the second tabs located on the same electrode being spaced apart along the length direction of the electrode and interconnected. The casing has a receiving cavity, and the wound cell is located in the receiving cavity.
[0005] The wound battery according to the embodiments of the present invention has at least the following beneficial effects: the four first tabs of the wound cell are used for electrical connection with the outside world, which can disperse the current and reduce the risk of lithium plating. Since the first tabs do not need to be brought together, bent and then led out, but are led out directly, the size of the area where the first tabs are brought together, bent and led out is saved, thereby saving the size occupied by the wound cell in the width direction of the battery housing cavity, thereby improving the volumetric energy density of the battery. Furthermore, since multiple second tabs are connected to each other, the current path between different positions of the electrode along the length direction and the first tabs is shortened, thereby enabling the battery to have a higher charging rate.
[0006] According to some embodiments of the present invention, the first electrode tab is located at the middle of the corresponding electrode along its length direction.
[0007] According to some embodiments of this utility model, the distance between two adjacent first electrodes is A, which satisfies A > 8mm.
[0008] According to some embodiments of the present invention, the first tab of one electrode and the first tab of the other electrode are respectively placed on both sides of the winding center axis of the wound cell.
[0009] According to some embodiments of the present invention, the number of second tabs in each of the electrode sheets is B, satisfying 25≤B≤35.
[0010] According to some embodiments of the present invention, all the second electrode ears located on the same electrode sheet are bent and folded to form a connecting plate portion, and the connecting plate portions of the two electrodes sheets are spaced apart.
[0011] According to some embodiments of the present invention, the connecting plate portion is parallel to the side wall of the wound cell perpendicular to the width direction.
[0012] According to some embodiments of the present invention, a receiving groove is provided on the side of the wound battery cell near the connecting plate portion, and the connecting plate portion is located in the receiving groove.
[0013] According to some embodiments of the present invention, the connecting plate portion is spaced apart from the side wall of the corresponding receiving groove.
[0014] According to some embodiments of the present invention, the distance between the connecting plate and the corresponding sidewall of the receiving groove is C, which satisfies 1mm≤C≤2mm.
[0015] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0016] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0017] Figure 1 This is a front view schematic diagram of a wound battery according to an embodiment of the present utility model;
[0018] Figure 2 This is a front view schematic diagram of the wound battery cell according to an embodiment of the present invention;
[0019] Figure 3This is a front view schematic diagram of the electrode sheet unfolding according to an embodiment of the present invention.
[0020] Figure label:
[0021] The components include a wound cell 100, an electrode 110, a first tab 111, a second tab 112, a connecting plate 113, and a receiving groove 120.
[0022] Casing 200. Detailed Implementation
[0023] 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 are only used to explain this utility model, and should not be construed as limiting this utility model.
[0024] In the description of this utility model, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the 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.
[0025] In the description of this utility model, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features or their sequential relationship.
[0026] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.
[0027] Reference Figures 1 to 3 This invention relates to a wound battery, comprising a wound cell 100 and a housing 200. The wound cell 100 is formed by winding an electrode assembly, which includes two electrodes 110 and a separator disposed between the two electrodes 110. Each electrode 110 has two first tabs 111 on one side along its length direction, and the two first tabs 111 are spaced apart along the length direction of the electrode 110. Each electrode 110 has multiple second tabs 112 on the other side along its length direction, and all the second tabs 112 on the same electrode 110 are spaced apart along the length direction of the electrode 110 and are interconnected. The housing 200 has a receiving cavity, and the wound cell 100 is located in the receiving cavity.
[0028] The four first tabs 111 of the wound cell 100 are used for electrical connection with the outside world, which can disperse the current and reduce the risk of lithium plating. Since the first tabs 111 do not need to be brought together, bent and then led out, but are led out directly, the size of the area where the first tabs 111 are brought together, bent and led out is saved, thereby saving the size occupied by the wound cell 100 in the width direction of the cavity of the battery casing 200, thereby improving the volumetric energy density of the battery. Furthermore, since multiple second tabs 112 are interconnected, the current path between different positions of the electrode 110 along the length direction and the first tabs 111 is shortened, thereby enabling the battery to have a higher charging rate.
[0029] Specifically, the arrangement of the four first tabs 111 reduces the distance between the head of the wound cell 100 and the head of the housing cavity of the casing 200, thereby improving the utilization rate of the space at the head of the battery housing cavity and increasing the volumetric energy density.
[0030] Specifically, in this embodiment, the width direction of the electrode 110 is the same as the width direction of the wound cell 100 and the wound battery. At this time, the first tab 111 of the wound cell 100 is located at the head of the wound battery, and the second tab 112 of the wound cell 100 is located at the tail of the wound battery. The head of the wound battery has four first tabs 111, which are staggered to reduce the non-tab area. The casing 200 is an aluminum-plastic film casing 200, which reduces the appearance problem of the battery head collapsing.
[0031] In this embodiment, the first tab 111 is located at the middle of the corresponding electrode 110 along its length. Placing the first tab 111 at the middle of the electrode 110 along its length makes it easier for the current paths from both ends of the electrode 110 to the first tab 111 to be relatively short, thereby improving the battery charging rate.
[0032] In this embodiment, the distance between two adjacent first tabs 111 is A, which satisfies A > 8mm. If the distance between the first tabs 111 is too small, a short circuit between them is likely to occur, posing a safety hazard during manufacturing. Therefore, making the distance between two adjacent tabs greater than 8mm significantly reduces the risk of short circuits between adjacent first tabs 111 and improves battery safety.
[0033] Specifically, the distance between two adjacent first electrodes 111 can be selected according to the actual needs of those skilled in the art.
[0034] In this embodiment, the first tab 111 of one electrode 110 and the first tab 111 of the other electrode 110 are positioned on opposite sides of the winding center axis of the wound cell 100. This arrangement of the first tabs 111, i.e., the first tabs 111 of the positive electrode 110 and the first tabs 111 of the negative electrode 110 being positioned on opposite sides of the winding center axis, ensures sufficient distance between the first tabs 111 of the positive electrode 110 and the first tabs 111 of the negative electrode 110. This arrangement also facilitates the connection of the two first tabs 111 of the positive electrode 110 to the positive electrode lead and the connection of the two first tabs 111 of the negative electrode 110 to the negative electrode lead, resulting in a simple and compact battery structure.
[0035] It is conceivable that in other embodiments, the arrangement of the two first tabs 111 of the two electrodes 110 can be in other ways, which are not limited here.
[0036] In this embodiment, the number of second tabs 112 on each electrode 110 is B, satisfying 25≤B≤35. If the number of second tabs 112 is too small, the uniformity of current distribution on the electrode 110 will be reduced, affecting the charging rate. If the number of second tabs 112 is too large, it will be difficult to align and stack the second tabs 112 on the same electrode 110, affecting the product yield. Therefore, when the number of second tabs 112 on the electrode 110 is 25≤B≤35, the current distribution on the electrode 110 can be made relatively uniform, thereby improving the charging rate and safety, and the production difficulty is relatively low, which is conducive to improving the product yield.
[0037] Specifically, the number of second tabs 112 on each electrode 110 can be any value within the above range. Those skilled in the art can configure it according to actual needs, such as 26, 28, 30, 32 or 34, or other values within the range.
[0038] In this embodiment, all the second tabs 112 located on the same electrode 110 are bent and folded to form a connecting plate portion 113, and the connecting plate portions 113 of the two electrodes 110 are spaced apart. By stacking all the second tabs 112 on the same electrode 110 to form the connecting plate portion 113, it is beneficial to the uniformity of current distribution along the length of the electrode 110, and the spacing between the two connecting plate portions 113 can avoid the risk of short circuit between the positive electrode 110 and the negative electrode 110 through the connecting plate portion 113, thereby improving the safety of battery production and use.
[0039] In this embodiment, the connecting plate portion 113 is parallel to the sidewall of the wound cell 100 perpendicular to the width direction, which allows the wound cell 100 to reduce its size along the width direction, thus improving the volumetric energy density of the wound battery. Specifically, the connecting plate portion 113 is bent to be parallel to the sidewall of the wound cell 100 along the width direction.
[0040] Specifically, the second tabs 112 can be fixed together by welding.
[0041] In other embodiments, all the second tabs 112 of the same electrode 110 can also be electrically connected in other ways, for example, by welding all the second tabs 112 of the same electrode 110 onto a conductive sheet to achieve electrical connection between the second tabs 112.
[0042] In this embodiment, a receiving groove 120 is provided on the side of the wound cell 100 near the connecting plate portion 113, and the connecting plate portion 113 is located within the receiving groove 120. Providing the receiving groove 120 reduces the protruding size of the connecting plate portion 113 relative to the main body of the wound cell 100, allowing the housing 200 of the same size to accommodate a wider main body of the wound cell 100. This increases the space for utilizing the active material of the battery, thereby improving the volumetric energy density of the wound battery.
[0043] In this embodiment, the connecting plate portion 113 is spaced apart from the sidewall of the corresponding receiving groove 120, so that the second electrode tab 112 can be bent and folded more easily, and there is a gap between the connecting plate portion 113 of the positive electrode 110 and the negative electrode 110, and there is a gap between the connecting plate portion 113 of the negative electrode 110 and the positive electrode 110, so as to avoid short circuit between the positive electrode 110 and the negative electrode 110.
[0044] In this embodiment, the distance C between the connecting plate portion 113 and the sidewall of the corresponding receiving groove 120 satisfies 1mm ≤ C ≤ 2mm. This reduces the risk of short circuit between the connecting plate portion 113 of one electrode 110 and another electrode 110, and also reduces the impact on the amount of active material, allowing the battery to maintain a high volumetric energy density. Specifically, the distance between the connecting plate portion 113 and the sidewall of the corresponding receiving groove 120 can be any value within the aforementioned range, and those skilled in the art can configure it according to actual needs.
[0045] Specifically, the second tab 112 has a dimension D along the length of the electrode 110, which satisfies 6mm≤D≤10mm, making it relatively easy to stack and fix, and resulting in a better overall performance.
[0046] Specifically, the depth of the receiving groove 120 is E, satisfying 1mm≤E≤2mm, which can relatively fully accommodate the connecting plate portion 113 and has little impact on the volumetric energy density of the battery. It is understood that the receiving groove 120 typically accommodates the entire connecting plate portion 113, thereby maximizing the utilization space of the active material and thus maximizing the volumetric energy density of the battery. Of course, in other embodiments, the receiving groove 120 may accommodate only a portion of the connecting plate portion 113, which can also increase the utilization space of some active material and thus improve the volumetric energy density of the battery.
[0047] Specifically, adhesive tape can be applied to the outside of the connecting plate portion 113 to keep the connecting plate portion 113 parallel to the side wall of the wound cell 100 perpendicular to the width direction, and to keep the position of the two relatively fixed.
[0048] Specifically, the first tab 111 is a welded tab welded to the empty foil area of the electrode 110, and the second tab 112 is a foil tab of the electrode 110.
[0049] Specifically, compared to the parallel structure of two single-tab wound batteries, this solution reduces the number of bending areas in the wound battery, thereby improving the space utilization of the wound cell and thus increasing the volumetric energy density. It has a relatively obvious advantage in application scenarios with high charging rates and multiple cells in parallel.
[0050] Specifically, compared to single-tab wound batteries, this solution improves the current density distribution of the electrode 110, thereby reducing heat generation during charging. The structure of two first tabs 111 on each electrode 110 also reduces internal resistance and charging time. Furthermore, the structure of two first tabs 111 on each electrode 110 reduces lithium plating in the vicinity of the first tabs 111, improving battery safety and reducing cycle capacity loss.
[0051] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0052] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.
Claims
1. A wound battery, characterized in that, include: A wound cell (100) is formed by winding an electrode assembly, the electrode assembly including two electrodes (110) and a separator disposed between the two electrodes (110). Each electrode (110) has two first tabs (111) on one side along its length direction, the two first tabs (111) are spaced apart along the length direction of the electrode (110), and each electrode (110) has a plurality of second tabs (112) on the other side along its length direction. All the second tabs (112) located on the same electrode (110) are spaced apart along the length direction of the electrode (110), and all the second tabs (112) located on the same electrode (110) are interconnected. The housing (200) is provided with a receiving cavity, and the wound cell (100) is located in the receiving cavity.
2. The wound battery according to claim 1, characterized in that: The first tab (111) is located at the middle of the corresponding electrode (110) along its length direction.
3. The wound battery according to claim 1, characterized in that: The distance between two adjacent first electrodes (111) is A, which satisfies A > 8 mm.
4. The wound battery according to claim 1, characterized in that: The first tab (111) of one of the electrodes (110) and the first tab (111) of the other electrode (110) are respectively placed on both sides of the winding center axis of the wound cell (100).
5. The wound battery according to claim 1, characterized in that: The number of second tabs (112) of each of the said pole pieces (110) is B, satisfying 25≤B≤35.
6. The wound battery according to claim 1, characterized in that: All the second tabs (112) located on the same electrode (110) are bent and folded to form a connecting plate portion (113), and the connecting plate portions (113) of the two electrodes (110) are spaced apart.
7. The wound battery according to claim 6, characterized in that: The connecting plate portion (113) is parallel to the sidewall of the wound cell (100) perpendicular to the width direction.
8. The wound battery according to claim 6, characterized in that: The wound cell (100) has a receiving groove (120) on the side near the connecting plate portion (113), and the connecting plate portion (113) is located in the receiving groove (120).
9. The wound battery according to claim 8, characterized in that: The connecting plate portion (113) is spaced apart from the sidewall of the corresponding receiving groove (120).
10. The wound battery according to claim 9, characterized in that: The distance between the connecting plate portion (113) and the side wall of the corresponding receiving groove (120) is C, which satisfies 1mm≤C≤2mm.