Battery cell and battery

Abstract

The battery cell comprises a positive pole piece and a negative pole piece, each of the positive pole piece and the negative pole piece comprises a pole piece body and a pole lug, and each pole lug comprises a root part connected with the pole piece body; the positive plate body, the diaphragm and the negative plate body are stacked and wound to form a winding structure, and each pole plate body in the winding structure comprises a straight section and an arc section; one side of the root part of the tab is connected with a straight section, the other side of the root part of the tab is connected with an arc section, one side connected with the arc section is provided with a first arc structure, the width of a connecting area of the first arc structure and the arc section is less than 0.087 H, and H is the width of the straight section connected with the tab in the layer of the winding structure. According to the utility model, by adjusting the width of the connecting area of each layer of lug root part and the arc section and the size of the arc structure of the lug root part, the problem of lug tearing caused by interference between the connecting part of the lug and the pole piece and the corner of the pole core is avoided, and the quality and the safety of the battery cell are improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to battery technical field, concretely relates to a kind of battery cell and battery. BACKGROUND

[0002] In the current winding structure battery cell of high power requirement, usually adopt the way of one tab per layer of pole piece to ensure the high power charge-discharge capability of battery cell, reduce battery cell resistance;But tab tail and pole piece junction place exist stress concentration, easily cause tab tear;Or for some battery cell width requirement is relatively narrow, and based on overcurrent capacity, and tab requirement is relatively wide, therefore tab and pole piece junction place very likely and the corner of pole core exist interference, cause tab tear. SUMMARY

[0003] In view of above prior art shortcomings, the purpose of the utility model is to provide a kind of battery cell and battery, to improve the problem that tab and pole piece junction place easily produce tab tear.

[0004] To achieve the above object and other related purposes, the utility model provides a kind of battery cell, comprising:

[0005] Positive pole piece, the positive pole piece includes first positive pole piece body and first positive tab, and the first positive tab includes the root portion connecting the positive pole piece body;

[0006] Negative pole piece, the negative pole piece includes first negative pole piece body and first negative tab, and the first negative tab includes the root portion connecting the first negative pole piece body;

[0007] Diaphragm, the positive pole piece body, the diaphragm and the negative pole piece body are laminated and wound to form winding structure, each the positive pole piece body and the negative pole piece body in the winding structure are included opposite flat section and the circular arc section located at the both ends of flat section;

[0008] Wherein, the root portion of the first positive tab and / or the first negative tab one side is connected with the flat section, other side is connected with the circular arc section, and the side connected with the circular arc section is provided as first circular arc structure, the width of the connecting area of the first circular arc structure and the circular arc section is less than 0.087H, wherein, H is the width of the flat section connected with the first positive tab and / or the flat section connected with the first negative tab in the layer of winding structure.

[0009] In a preferred embodiment of the utility model, along the direction from inside to outside of the winding structure, the radius of the first circular arc structure gradually increases in arithmetic progression.

[0010] In a preferred embodiment of the utility model, the side of the first positive tab and / or the first negative tab connected with the flat section is provided as second circular arc structure.

[0011] In one preferred embodiment of the utility model, the radius of the second arc structure of the first positive pole lug and / or the first negative pole lug is same or gradually increases from inside to outside along the layer number of the winding structure.

[0012] In one preferred embodiment of the utility model, the radius of the first arc structure is greater than the radius of the second arc structure.

[0013] In one preferred embodiment of the utility model, the radius of the first arc structure of the adjacent two layers in the winding structure is Wherein X represents the width of the connecting area of the first arc structure and the arc segment, n represents the layer number of the flat section of the first positive pole lug and / or the flat section of the first negative pole lug in the winding structure, and N represents the total layer number of the winding structure.

[0014] In one preferred embodiment of the utility model, the first positive pole lug further comprises a top portion away from the first positive pole body, the first negative pole lug further comprises a top portion away from the first negative pole body, and the top portion of the first positive pole lug and / or the first negative pole lug is provided as a trapezoidal shape or provided as a circular arc shape on both sides of the top portion.

[0015] In one preferred embodiment of the utility model, the positive pole piece further comprises a second positive pole body and a second positive pole lug, and the root portions of the second positive pole lug are connected to the flat section on both sides;

[0016] The negative pole piece further comprises a second negative pole body and a second negative pole lug, and the root portions of the second negative pole lug are connected to the flat section on both sides;

[0017] The root portions of the second positive pole lug and / or the second negative pole lug are provided as a third arc structure on both sides.

[0018] In one preferred embodiment of the utility model, the radius of the third arc structure is same or gradually increases along the direction from inside to outside of the winding structure.

[0019] The utility model further provides a single battery, which comprises a shell, a cover plate and the battery cell as any one of the above embodiments, the battery cell is arranged in the shell, the cover plate is fixedly connected with the shell and is electrically connected with the battery cell.

[0020] The utility model provides a kind of electric core and battery, and the root of connecting tab and pole piece is designed as arc structure, wherein the root of connecting pole piece arc segment is designed as first arc structure, and the width size of the first arc structure connected with the pole piece body arc segment connection area of different layers of pole piece body in winding structure is adjusted, and the radius of the first arc structure is designed gradually increases from inside to outside along the layer number of winding structure, which adjusts the size of the first arc structure of each layer tab, so that tab can adapt to the shape of the layer pole piece, reduce the risk of tab tearing, improve battery safety, and make full use of the characteristics that the corner of outer layer pole core is relatively large, carry out equal difference arc structure design, play the effect that inner ring small arc structure adapts to equipment, and outer ring large arc structure protects tab, avoid tab tail and pole piece connection place due to stress concentration and cause tab tearing, and avoid the problem that tab and pole piece connection place and the corner of pole core interference and cause tab tearing, improve electric core quality and safety. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will be briefly introduced to the drawings needed to be used for the embodiment description, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without creating labor.

[0022] Figure 1 It is the structural schematic diagram of electric core in one embodiment of the utility model.

[0023] Figure 2 It is the overhead schematic diagram of electric core in one embodiment of the utility model.

[0024] Label explanation:

[0025] 10, positive pole piece;20, negative pole piece;11, first positive pole piece body;12, first positive lug;21, first negative pole piece body;22, first negative lug;101, flat section;102, arc section;301, first arc structure;302, second arc structure;13, second positive pole piece body;14, second positive lug;23, second negative pole piece body;24, second negative lug;303, third arc structure. DETAILED DESCRIPTION

[0026] The following embodiments and features in the embodiments can be combined with each other under the condition of no conflict.

[0027] It is to be noted that the drawings provided in the following embodiments only schematically illustrate the basic concept of the present application, and only the components related to the present application are shown in the drawings, rather than the number, shape and size of the components in actual implementation. The shape, number and proportion of each component in actual implementation can be changed at will, and the layout of the components can be more complex.

[0028] Please refer to Figure 1 and Figure 2 The purpose of the present application is to provide a battery and an electrode to improve the problem that the tab is easily torn at the connection between the tab and the electrode. Specifically, the battery includes a positive electrode 10, a negative electrode 20 and a separator, wherein the positive electrode 10 includes a first positive electrode body 11 and a first positive tab 12, the negative electrode 20 includes a first negative electrode body 21 and a first negative tab 22, and the positive electrode body 11, the separator and the negative electrode body 12 are stacked and wound to form a winding structure.

[0029] Please refer to Figure 1 and Figure 2 In this embodiment, each of the positive electrode body 11 and the negative electrode body 21 in the winding structure includes opposite flat sections 101 and circular arc sections 102 located at both ends of the flat sections 101, and the first positive tab 12 includes a root connected to the positive electrode body 11, and the first negative tab 22 includes a root connected to the negative electrode body 21. One side of the root of the first positive tab 12 and / or the first negative tab 22 is connected to the flat section 101, and the other side is connected to the circular arc section 102. One side of the circular arc section 102 is provided as a first circular arc structure 301. Specifically, in the positive electrode 10, one side of the root of the first positive tab 12 is connected to the flat section 101 of the first positive electrode body 11, and the other side is connected to the circular arc section 102 of the first positive electrode body 11. In the negative electrode 20, one side of the root of the first negative tab 22 is connected to the flat section 101 of the first negative electrode body 21, and the other side is connected to the circular arc section 102 of the first negative electrode body 21. One side of the circular arc section 102 of the first positive tab 12 and the first negative tab 22 connected to the respective electrode body is provided as a first circular arc structure 301 to reduce stress concentration and avoid tab tearing.

[0030] Please refer toFigure 1 and Figure 2 As shown in FIG. 1 and FIG. 2, in the embodiment, the width of the connection area between the first arc structure 301 and the arc segment 102 is less than 0.087H, wherein H is the width of the flat segment 101 connected with the first positive tab 12 and / or the flat segment 101 connected with the first negative tab 22 in the layer where the winding structure is located. For example, when the flat segment 101 connected with the first positive tab 11 is in the third layer from the inside to the outside of the winding structure, the width refers to the distance between the two flat segments 101 in the third layer in the direction from the inside to the outside of the winding structure. The new type adjusts the width of the connection area between the tab root and the arc segment of each layer to avoid the problem of tab tearing caused by the interference between the tab connection and the corner of the pole piece, thereby improving the quality and safety of the battery cell. The size of the first arc structure 301 of each layer of tab is determined according to the thickness of the pole piece of different layers, so that the tab can adapt to the shape of the pole piece of the layer, thereby reducing the risk of tab tearing and improving the safety of the battery.

[0031] Please refer to Figure 1 and Figure 2 As shown in FIG. 1 and FIG. 2, in the embodiment, the radius of the first arc structure gradually increases from the inside to the outside in the direction from the inside to the outside of the winding structure. Preferably, the radius of the first arc structure gradually increases in an arithmetic sequence, so that the radius of the first arc structure 301 of the tab in the inner layer is smaller, and the radius of the first arc structure 302 of the tab in the outer layer is larger, thereby achieving the effect of small inner arc structure adapting to the equipment and large outer arc structure protecting the tab. It can be understood that when only the root side of the first positive tab 12 or the first negative tab 22 is connected with the flat segment 101, and the other side is connected with the arc segment 102, the radius of the first arc structure 301 of the first positive tab 12 or the first negative tab 22 connected with the arc segment 102 gradually increases. When the root side of the first positive tab 12 and the first negative tab 22 is connected with the flat segment 101, and the other side is connected with the arc segment 102, the radius of the first arc structure 301 of the first positive tab 12 and the first negative tab 22 connected with the arc segment 102 gradually increases, i.e. the radius of the first arc structure 301 of the first positive tab 12 in the outer layer is larger than that of the first negative tab 22 in the inner layer, and the radius of the first arc structure 301 of the first negative tab 22 in the outer layer is larger than that of the first positive tab 12 in the inner layer.

[0032] Please refer to Figure 1 and Figure 2As shown, in the embodiment, the radius of the first circular arc structure 301 of the adjacent two layers in the winding structure is different wherein X represents the width of the connection area between the first circular arc structure 301 and the circular arc segment 102, n represents the number of layers of the flat segment 101 of the first positive tab 12 and / or the flat segment 22 of the first negative tab 22 in the winding structure, N represents the total number of layers of the winding structure, and the size of the inner chamfer of each tab is determined according to the thickness of the core of different layers, so that the tab can adapt to the shape of the layer of the pole piece, reduce the risk of tab tearing, and improve the safety of the battery.

[0033] As shown in Figure 1 and Figure 2 As shown, in the embodiment, one side of the flat segment 101 connected to the first positive tab 12 and / or the first negative tab 22 is provided with a second circular arc structure 302, and the radius of the second circular arc structure 302 of the first positive tab 12 and / or the first negative tab 22 is the same, or along the direction of the number of layers of the winding structure from inside to outside, the radius of the second circular arc structure 302 of the first positive tab 12 and / or the first negative tab 22 gradually increases. Preferably, on the same first positive tab 12 and / or the same first negative tab 22, the radius of the first circular arc structure 301 is greater than the radius of the second circular arc structure, so as to further avoid the problem of tab tearing caused by stress concentration at the connection between the tail of the tab and the pole piece, and avoid the problem of tab tearing caused by interference between the connection between the tab and the pole piece and the corner of the core, improve the quality and safety of the battery.

[0034] As shown in Figure 1 and Figure 2 As shown, in the embodiment, the first positive tab 12 further includes a top portion away from the first positive pole body 11, and the first negative tab 22 further includes a top portion away from the first negative pole body 21, and the top portion of the first positive tab 12 and / or the first negative tab 22 is provided with a trapezoidal shape or a circular arc shape on both sides of the top portion, so as to be convenient for replacement and connection with other structures.

[0035] As shown in Figure 1 and Figure 2 As shown, in the embodiment, the positive pole piece 10 further includes a second positive pole body 13 and a second positive tab 14, both sides of the root of the second positive tab 14 are connected to the flat segment 101 of the second positive pole body 13, the negative pole piece 20 further includes a second negative pole body 23 and a second negative tab 24, both sides of the root of the second negative tab 24 are connected to the flat segment 101 of the second negative pole body 23, and both sides of the root of the second positive tab 14 and / or the second negative tab 24 are provided with a third circular arc structure 303, wherein the radii of the third circular arc structures 303 are the same, or along the direction of the winding structure from inside to outside, the radii of the third circular arc structures 303 gradually increase, to avoid tab tearing caused by stress concentration at the connection between the root of the tab and the pole piece.

[0036] Referring to Figure 1 and Figure 2 The utility model also provides a single battery, including casing, apron and electric core, the electric core sets up in the casing, apron with casing fixed connection is connected with electric core electricity, this electric core with the structure same or similar as the electric core described in above embodiment, to avoid repetition, here no longer tediously.

[0037] The utility model discloses a kind of electric core and battery, tab and pole piece connecting root are designed as circular arc structure, wherein the root of connection with pole piece circular arc segment is designed as first circular arc structure, and the width size of the first circular arc structure connected with pole piece body connecting area in different layers of winding structure is adjusted, and the radius of the first circular arc structure is designed gradually increases from inside to outside along the layer number of winding structure, which adjusts the size of the first circular arc structure of each layer tab, so that tab can adapt to the shape of the layer pole piece, reduce the risk of tab tearing, improve battery safety, and make full use of the characteristics that the corner of outer pole core is relatively large, carry out equal difference circular arc structure design, play the effect that small circular arc structure of inner ring adapts to equipment, and large circular arc structure of outer ring protects tab, avoid the problem that tab tail and pole piece connecting place are torn due to stress concentration and avoid tab and pole piece connecting place and the corner of pole core interference and cause tab tearing, improve electric core quality and safety.

[0038] The above embodiments are only illustrative of the principles and effects of the utility model, and are not used to limit the utility model. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the utility model. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought disclosed by the utility model should be covered by the claims of the utility model.

[0039] In the description herein, many specific details are provided, such as examples of components and / or methods, to provide a thorough understanding of embodiments of the utility model. One skilled in the relevant art will recognize, however, that embodiments of the utility model can be practiced without one or more of the specific details, or with other devices, systems, components, methods, materials, parts, and / or the like. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail in order to avoid obscuring aspects of embodiments of the utility model.

[0040] References in the specification to "one embodiment", "an embodiment", or "the embodiments", mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application, and is not necessarily included in all embodiments. The various appearances of the phrase "in one embodiment" or "in an embodiment" or "in the embodiments" in various places in the specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that the application encompasses other variations, modifications, and alternatives of the application as can be suggested by the principles of the application and the following examples.

[0041] It will also be understood that one or more of the elements illustrated in the drawings, alone or in combination, can also be implemented in a more separated or more integrated manner. In addition, it will be understood that the application can also include other elements not specifically shown in the drawings.

[0042] In addition, unless explicitly stated otherwise, any directional or position terms used herein, such as "above", "below", "up", "down", "left", "right", "out", "in", "front", "back", "bottom", "top", "under", "above", "between", and the like, should be construed to be illustrative only and not restrictive. The use of such terms is merely to facilitate recognition of certain aspects of elements described herein and to further aid the understanding of the various aspects of the application. Further, unless otherwise indicated, the use of terms like "or" have been used in their general sense, and are intended to mean "and / or" unless otherwise indicated. Combinations of components or steps will also be implied where the context allows, even if not expressly recited in the claims.

[0043] As used in the description of the application and throughout the claims that follow, unless otherwise indicated the use of "a", "an", and "the" includes plural references. Also, as used in the description of the application and throughout the claims that follow, unless otherwise indicated the meaning of "in" includes "in" and "on".

[0044] The above description of the illustrated embodiments of the application (including what is described in the abstract) is not intended to be exhaustive or to limit the application to the precise forms disclosed. While specific embodiments of, and examples for, the application are described herein for illustrative purposes, various equivalent modifications are possible within the spirit and scope of the application, as those skilled in the relevant art will recognize and appreciate. As indicated, these modifications can be made to the above described embodiments and yet the application will remain within the scope of the application. Accordingly, while the application is susceptible to various modifications and alternative forms, specific embodiments and examples thereof have been shown and described in detail herein. It should be understood, however, that the application is not to be limited to the particular embodiments or examples disclosed, but to include all possible embodiments which would be within the scope of the above description.

[0045] The systems and methods have been described herein in general terms as to aid in understanding the details of the application. In addition, various specific details have been presented to provide a general understanding of the embodiments of the application. However, a person skilled in the relevant art will recognize that the embodiments of the application can be practiced without one or more of the specific details, or with other devices, systems, assembles, methodologies, components, materials, and / or the like. In other instances, well known structures, materials, and / or operations have not been shown or described in detail to avoid obscuring aspects of the embodiments of the application.

[0046] Thus, although the present application has been described herein with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosures, and it will be appreciated that in some instances some features of the application can be employed without a corresponding use of other features, without departing from the scope of the present application as set forth in the appended claims. Therefore, many modifications can be made to carry out the application in different particulars within the scope of the appended claims. The application is not limited to the specific embodiments described herein, but only to the specific language set forth in the claims.

Claims

1. A battery cell, characterized in that: include: A positive electrode sheet, the positive electrode sheet comprising a first positive electrode sheet body and a first positive electrode tab, the first positive electrode tab comprising a root portion connected to the positive electrode sheet body; A negative electrode sheet, the negative electrode sheet comprising a first negative electrode sheet body and a first negative electrode tab, the first negative electrode tab comprising a root portion connected to the first negative electrode sheet body; The positive electrode sheet body, the separator and the negative electrode sheet body are stacked and wound to form a winding structure, wherein each of the positive electrode sheet body and the negative electrode sheet body in the winding structure includes opposite straight sections and arc sections located at both ends of the straight sections; One side of the root of the first positive electrode ear and / or the first negative electrode ear is connected to the straight segment, and the other side is connected to the arc segment, and the side connected to the arc segment is set to a first arc structure, and the width of the connection area between the first arc structure and the arc segment is less than 0.087H, wherein H is the width of the straight segment connected to the first positive electrode ear and / or the straight segment connected to the first negative electrode ear at the layer where the winding structure is located.

2. The battery cell according to claim 1, characterized in that Along the direction from the inside to the outside of the winding structure, the radius of the first arc structure gradually increases in an arithmetic progression.

3. The battery cell according to claim 1, characterized in that The side of the first positive electrode tab and / or the first negative electrode tab connected to the straight section is configured as a second arc structure.

4. The battery cell according to claim 3, characterized in that The radius of the second arc structure of the first positive electrode tab and / or the first negative electrode tab is the same or the number of layers along the winding structure gradually increases from the inside to the outside.

5. The battery cell according to claim 3, characterized in that: The radius of the first arc structure is greater than the radius of the second arc structure.

6. The battery cell according to claim 1, characterized in that The radius of the first arc structure of two adjacent layers in the winding structure differs Wherein, X represents the width of the connection area between the first arc structure and the arc segment, n represents the number of layers of the winding structure with the straight section of the first positive electrode tab and / or the straight section of the first negative electrode tab, and N represents the total number of layers of the winding structure.

7. The battery cell according to claim 1, characterized in that The first positive electrode tab further includes a top away from the first positive electrode sheet body, and the first negative electrode tab further includes a top away from the first negative electrode sheet body. The top of the first positive electrode tab and / or the first negative electrode tab is set to be trapezoidal or the two sides of the top are set to be arc-shaped.

8. The battery cell according to claim 1, characterized in that The positive electrode sheet further includes a second positive electrode sheet body and a second positive electrode tab, and both sides of the root of the second positive electrode tab are connected to the straight section; The negative electrode plate further includes a second negative electrode plate body and a second negative electrode tab, and both sides of the root of the second negative electrode tab are connected to the straight section; Both sides of the root of the second positive electrode tab and / or the second negative electrode tab are configured as a third arc structure.

9. The battery cell according to claim 8, characterized in that The radius of the third arc structure is the same, or the radius of the third arc structure gradually increases from the inside to the outside of the winding structure.

10. A battery, characterized in that: The battery cell comprises a shell, a cover plate and the battery cell according to any one of claims 1 to 9, wherein the battery cell is arranged in the shell, and the cover plate is fixedly connected to the shell and electrically connected to the battery cell.

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