Battery cell and battery

Abstract

The battery cell comprises a battery cell body, the battery cell body comprises a positive plate, a diaphragm and a negative plate which are mutually stacked and wound, and the diaphragm is arranged between the positive plate and the negative plate; the positive tab is connected to the positive plate; the negative tab is connected to the negative plate; and at least one of the positive tab and the negative tab is arranged in an arc-shaped bending manner along the winding direction of the battery cell body. According to the battery cell provided by the utility model, at least one of the positive tab and the negative tab is arranged in the arc-shaped bending manner along the winding direction of the battery cell body, so that the positive tab and / or the negative tab can correspondingly adapt to the appearance shape of the battery cell body and can be better attached to the surface of a pole piece; therefore, the phenomenon of relatively large acting force on the two side edges of the positive tab and / or the negative tab is avoided, the extrusion effect of the two side edges of the positive tab and / or the negative tab on the battery cell body is weakened, and the risk of deformation and even breakage of the battery cell body is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery core and a battery. Background Art

[0002] With the continuous updating and development of electronic products, the cylindrical batteries and button batteries used in electronic products are also updated and developed.

[0003] The battery cells of button batteries and cylindrical batteries are usually cylindrical, and the tabs on the battery cells are rectangular. When the battery cells expand during charging and discharging, the battery cells will exert force on the tabs, and the tabs will also react to the battery cells. Since the contact area between the two sides of the tabs and the battery cells is small, the force on both sides will be relatively large. As a result, there is a high risk that the two sides of the tabs will squeeze the battery cells, causing deformation or even breakage. Utility Model Content

[0004] The main purpose of the utility model is to provide a battery cell, which aims to solve the problem that during the expansion process of the current battery cell, the forces acting on both sides of the tab are relatively large, resulting in a high risk of the battery cell being squeezed and deformed or even broken by the two sides of the tab.

[0005] The utility model provides a battery core, which includes:

[0006] A battery cell body, the battery cell body comprising a positive electrode sheet, a separator, and a negative electrode sheet stacked and wound together, the separator being disposed between the positive electrode sheet and the negative electrode sheet;

[0007] A positive electrode tab, the positive electrode tab being connected to the positive electrode sheet;

[0008] A negative electrode tab, connected to the negative electrode sheet;

[0009] Wherein, at least one of the positive electrode tab and the negative electrode tab is arranged to be curved in an arc shape along the winding direction of the battery cell body.

[0010] In some embodiments, when the positive electrode tab is arranged in an arc shape along the winding direction of the battery cell body, the curvature of the position where the positive electrode sheet connects to the positive electrode tab is the same as the curvature of the positive electrode tab.

[0011] In some embodiments, when the positive electrode ear is bent in an arc shape along the winding direction of the battery body, the cross-sectional shape of the positive electrode ear is a first arc, the first arc has a first endpoint A and a second endpoint B, and the central angle corresponding to the first arc is ∠α, wherein ∠α=(L AB / 2πR)*360°;

[0012] Among them, L ABis the straight-line distance between the first endpoint A and the second endpoint B, and R is the radius of the battery cell body.

[0013] In some embodiments, the angle range of ∠α is 10° to 75°.

[0014] In some embodiments, the positive electrode sheet has a first empty foil area, a first dressing area, and a second empty foil area sequentially arranged along the winding direction of the battery body;

[0015] The positive electrode tab is arranged in any one of the first empty foil area, the first dressing area, and the second empty foil area. When the positive electrode tab is arranged in the first dressing area, the first dressing area has a first accommodating groove for accommodating the positive electrode tab.

[0016] In some embodiments, when the negative electrode tab is arranged in an arc shape along the winding direction of the battery cell body, the curvature of the position where the negative electrode sheet connects to the negative electrode tab is the same as the curvature of the negative electrode tab.

[0017] In some embodiments, when the negative electrode ear is bent in an arc shape along the winding direction of the battery body, the cross-sectional shape of the negative electrode ear is a second arc, the second arc has a third endpoint C and a fourth endpoint D, and the central angle corresponding to the second arc is ∠β, wherein ∠β=(L CD / 2πR)*360°;

[0018] Among them, L CD is the straight-line distance between the third endpoint C and the fourth endpoint D, and R is the radius of the battery cell body.

[0019] In some embodiments, the angle range of ∠β is 10° to 75°.

[0020] In some embodiments, the negative electrode sheet has a third empty foil area, a second dressing area, and a fourth empty foil area sequentially arranged along the winding direction of the battery body;

[0021] The negative electrode tab is arranged in any one of the third empty foil area, the second dressing area and the fourth empty foil area. When the negative electrode tab is arranged in the second dressing area, the second dressing area has a second accommodating groove for accommodating the negative electrode sheet.

[0022] The present invention also provides a battery, comprising a housing and the aforementioned battery core, wherein the battery core is disposed in the housing.

[0023] The battery cell provided by the present invention has at least one of the positive and negative tabs bent in an arc shape along the winding direction of the battery cell body. In this way, the tabs (positive and / or negative tabs) can adapt to the outer shape of the battery cell body and fit better on the surface of the electrode sheet. When the battery cell body expands during the charging and discharging process, since the outer shape of the tabs is adapted to the battery cell body, the force generated by the expansion of the battery cell body will be evenly distributed on the tabs (positive and / or negative tabs), and the force of the tabs (positive and / or negative tabs) acting on the battery cell body will also be uniform, avoiding the phenomenon that the force on both sides of the tabs (positive and / or negative tabs) is relatively large, weakening the squeezing effect of the two sides of the tabs (positive and / or negative tabs) on the battery cell body, and reducing the risk of deformation or even breakage of the battery cell body. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of a battery cell in one embodiment of the present utility model;

[0025] Figure 2 This is a schematic structural diagram of the positive electrode ear in one embodiment of the present utility model;

[0026] Figure 3 This is a schematic structural diagram of the negative electrode ear in one embodiment of the present invention;

[0027] Figure 4 for Figure 1 A schematic structural diagram of the positive electrode sheet in the embodiment;

[0028] Figure 5 for Figure 1 A schematic structural diagram of the negative electrode sheet in the embodiment;

[0029] Description of Figure Numbers:

[0030] Label name Label name 100 battery cells 110 Battery cell body 120 positive electrode ear 130 Negative electrode ear 111 positive electrode 112 negative electrode 1111 First empty foil area 1112 First dressing area 1113 Second empty foil area 1114 First accommodating groove 1121 The third empty foil area 1122 Second dressing area 1123 Fourth empty foil area 1124 Second accommodating groove

[0031] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the schemes in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0034] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element.

[0035] In addition, the descriptions of "first," "second," etc. in this utility model are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this utility model.

[0036] The present invention provides a battery cell 100, referring to Figure 1 , including: a battery cell body 110. The battery cell body 110 includes a positive electrode sheet 111, a separator, and a negative electrode sheet 112, which are stacked and wound together. The separator is arranged between the positive electrode sheet 111 and the negative electrode sheet 112. Specifically, the positive electrode sheet 111, the separator, and the negative electrode sheet are stacked and wound in sequence to form the battery cell body 110.

[0037] Positive electrode tab 120 and negative electrode tab 130. The positive electrode tab 120 is correspondingly connected to the positive electrode sheet 111, and one end of the positive electrode tab 120 is exposed outside the positive electrode sheet 111 for connection to an external circuit; the negative electrode tab 130 is correspondingly connected to the negative electrode sheet 112, and one end of the negative electrode tab 130 is exposed outside the negative electrode sheet 112 for connection to an external circuit. At least one of the positive electrode tab 120 and the negative electrode tab 130 is arranged in an arc shape along the winding direction of the battery cell body 110. Optionally, the positive electrode tab 120 is arranged in an arc shape along the winding direction of the battery cell body 110; or, the negative electrode tab 130 is arranged in an arc shape along the winding direction of the battery cell body 110; or, both the positive electrode tab 120 and the negative electrode tab 130 are arranged in an arc shape along the winding direction of the battery cell body 110. Furthermore, when the positive electrode tab 120 and / or the negative electrode tab 130 is bent, there can be multiple bending positions, for example, bending only at the connection between the positive electrode tab 120 and / or the negative electrode tab 130 and the battery cell body 110, or bending the entire positive electrode tab 120 and / or the negative electrode tab 130, without limitation here.

[0038] The battery cell 100 provided by the present invention has at least one of the positive tab 120 and the negative tab 130 bent in an arc shape along the winding direction of the battery cell body 110. In this way, the tabs (positive tab 120 and / or negative tab 130) can adapt to the outer shape of the battery cell body 110 and better fit on the surface of the electrode sheet. When the battery cell body 110 expands during the charge and discharge process, the tabs (positive tab 120 and / or negative tab 130) are adapted to the outer shape of the battery cell body 110, and the battery cell body 110 is not deformed. The force generated during expansion will be evenly distributed on the tabs (positive tab 120 and / or negative tab 130), and the force exerted by the tabs (positive tab 120 and / or negative tab 130) on the cell body 110 will also be even, thereby avoiding the phenomenon that the force on both sides of the tabs (positive tab 120 and / or negative tab 130) is relatively large, reducing the squeezing effect of the two sides of the tabs (positive tab 120 and / or negative tab 130) on the cell body 110, and reducing the risk of deformation or even breakage of the cell body 110.

[0039] In some embodiments, when the positive electrode tab 120 is curved along the winding direction of the battery cell body 110, the curvature of the positive electrode sheet 111 where it connects to the positive electrode tab 120 is the same as the curvature of the positive electrode tab 120. The positive electrode tab 120 is made of a soft metal, which has high plasticity and is easier to bend. Optionally, the soft metal is an aluminum alloy or a copper alloy. It should be noted that the curvature mentioned in this embodiment refers to the degree of bending of the positive electrode sheet 111 and the positive electrode ear 120. During the battery charge and discharge cycle, the positive electrode sheet 111 will expand and squeeze the positive electrode ear 120 connected to it. Because the curvature of the position where the positive electrode sheet 111 is connected to the positive electrode ear 120 is the same as the curvature of the positive electrode ear 120, the positive electrode ear 120 can be completely fitted on the surface of the positive electrode sheet 111. In this case, even if the positive electrode sheet 111 expands, the positive electrode ear 120 can evenly distribute the pressure applied to the battery cell body 110 without causing the stress to be mostly concentrated on the side of the positive electrode ear 120, thereby reducing the risk of the positive electrode ear 120 squeezing the battery cell body 110 at the side to deform, deposit lithium and break.

[0040] Reference Figure 2 In some embodiments, when the positive electrode tab 120 is bent in an arc shape along the winding direction of the battery cell body 110, the cross-sectional shape of the positive electrode tab 120 is a first arc. The first arc has a first endpoint A and a second endpoint B. The central angle corresponding to the first arc is ∠α, ∠α=(L AB / 2πR)*360°; where L AB is the straight-line distance between the first endpoint A and the second endpoint B, and R is the radius of the cell body 110. In this embodiment, the central angle is the angle with the vertex at the center of the circle, with the center being point O. The central angle ∠α corresponding to the first arc is ∠AOB, where the straight-line distance between the first endpoint A and the second endpoint B is a fixed value, and the angle ∠α changes with the radius R of the cell body 110. When the radius R of the cell body 110 increases, the angle ∠α decreases, allowing the positive tab 120 to better fit the surface of the positive electrode sheet 111 in the cell body 110. This reduces the risk of stress concentration on the side of the positive tab 120 when the positive electrode sheet 111 expands, which could cause deformation, lithium deposition, and breakage of the cell body 110.

[0041] In some embodiments, the angle range of ∠ACB is 10° to 75°. That is, the angle of ∠α can be set within the range of 10° to 75°, for example, the angle of ∠α is 10°, 42.5° or 75°. The angle of ∠α can be set with reference to the radius R of the battery cell body 110. For example, when the radius R of the battery cell body 110 is large, the angle of ∠α can be set to 10°; when the radius R of the battery cell body 110 is medium, the angle of ∠αB can be set to 42.5°; when the radius R of the battery cell body 110 is small, the angle of ∠α can be set to 75°. The above data is only exemplary and not restrictive.

[0042] Reference Figure 4 In some embodiments, the positive electrode sheet 111 has a first empty foil area 1111, a first dressing area 1112, and a second empty foil area 1113, which are sequentially arranged along the winding direction of the battery cell body 110; the positive electrode tab 120 is arranged in any one of the first empty foil area 1111, the first dressing area 1112, and the second empty foil area 1113. When the positive electrode tab 120 is arranged in the first dressing area 1112, the first dressing area 1112 has a first accommodating groove 1114 for accommodating the positive electrode tab 120. Among them, optionally, the positive electrode ear 120 is arranged in the first empty foil area 1111, specifically, the positive electrode sheet 111 is wound from the end away from the first empty foil area 1111, and the positive electrode ear 120 is welded to the first empty foil area 1111 after the winding is completed; or, the positive electrode ear 120 is arranged in the second empty foil area 1113, specifically, the positive electrode sheet 111 is wound from the end away from the second empty foil area 1113, and the positive electrode ear 120 is welded to the second empty foil area 1113 after the winding is completed; or, the positive electrode ear 120 is arranged in the first dressing area 1112, specifically, part of the active material in the first dressing area 1112 is scraped off to form a first receiving groove 1114, and then the positive electrode ear 120 is wound from one end of the positive electrode sheet 111, and when it is wound to the first receiving groove 1114, the positive electrode ear 120 is welded to the first receiving groove 1114 and then wound.

[0043] In some embodiments, when the negative electrode tab 130 is curved along the winding direction of the battery cell body 110, the curvature of the negative electrode sheet 112 at the location where it connects to the negative electrode tab 130 is the same as the curvature of the negative electrode tab 130. The negative electrode tab 130 is made of a soft metal, which has strong plasticity and is easier to bend. Optionally, the soft metal is a nickel alloy or a copper alloy. It should be noted that the curvature mentioned in this embodiment refers to the degree of bending of the negative electrode sheet 112 and the negative electrode ear 130. During the battery charge and discharge cycle, the negative electrode sheet 112 will expand and squeeze the negative electrode ear 130 connected to it. Because the curvature of the position where the negative electrode sheet 112 is connected to the negative electrode ear 130 is the same as the curvature of the negative electrode ear 130, the negative electrode ear 130 can be completely fitted on the surface of the negative electrode sheet 112. In this case, even if the negative electrode sheet 112 expands, the negative electrode ear 130 can evenly distribute the pressure applied to the battery cell body 110 without causing the stress to be mostly concentrated on the side of the negative electrode ear 130, thereby reducing the risk of the negative electrode ear 130 squeezing the battery cell body 110 at the side to deform, deposit lithium and break.

[0044] Reference Figure 3 In some embodiments, when the negative electrode tab 130 is bent in an arc shape along the winding direction of the battery cell body 110, the cross-sectional shape of the negative electrode tab 130 is a second arc. The second arc has a third endpoint C and a fourth endpoint D. The central angle corresponding to the second arc is ∠β, ∠β=(L CD / 2πR)*360°; where L CD is the straight-line distance between the third endpoint C and the fourth endpoint D, and R is the radius of the cell body 110. In this embodiment, the central angle is the angle with the vertex at the center of the circle, with the center being point O. The central angle ∠β corresponding to the second arc is ∠COD, where the straight-line distance between the third endpoint C and the fourth endpoint D is a fixed value, and the angle ∠β varies with the radius R of the cell body 110. When the radius of the cell body 110 increases, the angle ∠β decreases. This allows the negative electrode tab 130 to better fit the surface of the negative electrode sheet 112 in the cell body 110, reducing the risk of stress concentration on the side of the negative electrode tab 130 when the negative electrode sheet 112 expands, which could cause deformation, lithium deposition, and fracture of the cell body 110.

[0045] In some embodiments, the angle range of ∠β is 10° to 75°. That is, the angle of ∠β can be set within the range of 10° to 75°, for example, the angle of ∠β is 10°, 42.5° or 75°. The angle of ∠β can be set with reference to the radius R of the battery cell body 110. For example, when the radius R of the battery cell body 110 is large, the angle of ∠β can be set to 10°; when the radius R of the battery cell body 110 is medium, the angle of ∠β can be set to 42.5°; when the radius R of the battery cell body 110 is small, the angle of ∠β can be set to 75°. The above data is only exemplary and not restrictive.

[0046] Reference Figure 5 In some embodiments, the negative electrode sheet 112 has a third empty foil area 1121, a second dressing area 1122, and a fourth empty foil area 1123, which are sequentially arranged along the winding direction of the battery cell body 110; the negative electrode tab 130 is arranged in any one of the third empty foil area 1121, the second dressing area 1122, and the fourth empty foil area 1123. When the negative electrode tab 130 is arranged in the second dressing area 1122, the second dressing area 1122 has a second accommodating groove 1124 for accommodating the negative electrode tab 130. Among them, optionally, the negative electrode ear 130 is arranged in the third empty foil area 1121, specifically, the negative electrode sheet 112 is wound from the end away from the third empty foil area 1121, and the negative electrode ear 130 is welded to the third empty foil area 1121 after the winding is completed; or, the negative electrode ear 130 is arranged in the fourth empty foil area 1123, specifically, the negative electrode sheet 112 is wound from the end away from the fourth empty foil area 1123, and the negative electrode ear 130 is welded to the fourth empty foil area 1123 after the winding is completed; or, the negative electrode ear 130 is arranged in the second dressing area 1122, specifically, part of the active material in the second dressing area 1122 is scraped off to form a second accommodating groove 1124, and then the winding is started from one end of the negative electrode sheet 112, and when it is wound to the second accommodating groove 1124, the negative electrode ear 130 is welded to the second accommodating groove 1124 and then wound.

[0047] The present invention also provides a battery comprising a housing and the aforementioned battery cell 100, wherein the battery cell 100 is housed within the housing. Since the present battery utilizes all of the technical solutions of all of the aforementioned embodiments, it possesses at least all of the technical effects provided by the technical solutions of the aforementioned embodiments, and therefore, no further details will be given here.

[0048] The above description is only part or preferred embodiments of the present invention. Neither the text nor the drawings can limit the scope of protection of the present invention. All equivalent structural transformations made by using the contents of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect application in other related technical fields are included in the scope of protection of the present invention.

Claims

1. A battery cell, characterized in that: include: A battery cell body, the battery cell body comprising a positive electrode sheet, a separator, and a negative electrode sheet stacked and wound together, the separator being disposed between the positive electrode sheet and the negative electrode sheet; A positive electrode tab, the positive electrode tab being connected to the positive electrode sheet; A negative electrode tab, connected to the negative electrode sheet; Wherein, at least one of the positive electrode tab and the negative electrode tab is arranged to be curved in an arc shape along the winding direction of the battery cell body.

2. The battery cell according to claim 1, characterized in that When the positive electrode tab is arranged in an arc shape along the winding direction of the battery cell body, the curvature of the position where the positive electrode sheet is connected to the positive electrode tab is the same as the curvature of the positive electrode tab.

3. The battery cell according to claim 1, characterized in that When the positive electrode ear is bent in an arc shape along the winding direction of the battery body, the cross-section of the positive electrode ear is a first arc, the first arc has a first end point A and a second end point B, the central angle corresponding to the first arc is ∠α, and ∠α=(L AB / 2πR)*360°; Among them, L AB is the straight-line distance between the first endpoint A and the second endpoint B, and R is the radius of the battery cell body.

4. The battery cell according to claim 3, characterized in that The angle range of ∠α is 10° to 75°.

5. The battery cell according to claim 1, characterized in that The positive electrode sheet comprises a first empty foil area, a first dressing area and a second empty foil area which are sequentially arranged along the winding direction of the battery body; The positive electrode tab is arranged in any one of the first empty foil area, the first dressing area, and the second empty foil area. When the positive electrode tab is arranged in the first dressing area, the first dressing area has a first accommodating groove for accommodating the positive electrode tab.

6. The battery cell according to claim 1, characterized in that When the negative electrode tab is arranged in an arc shape along the winding direction of the battery cell body, the curvature of the position where the negative electrode sheet is connected to the negative electrode tab is the same as the curvature of the negative electrode tab.

7. The battery cell according to claim 1, characterized in that When the negative electrode ear is bent in an arc shape along the winding direction of the battery body, the cross-sectional shape of the negative electrode ear is a second arc, the second arc has a third endpoint C and a fourth endpoint D, and the central angle corresponding to the second arc is ∠β, wherein ∠β=(L CD / 2πR)*360°; Among them, L CD is the straight-line distance between the third endpoint C and the fourth endpoint D, and R is the radius of the battery cell body.

8. The battery cell according to claim 7, characterized in that: The angle range of ∠β is 10° to 75°.

9. The battery cell according to claim 1, characterized in that: The negative electrode sheet has a third empty foil area, a second dressing area and a fourth empty foil area sequentially arranged along the winding direction of the battery body; The negative electrode tab is arranged in any one of the third empty foil area, the second dressing area and the fourth empty foil area. When the negative electrode tab is arranged in the second dressing area, the second dressing area has a second accommodating groove for accommodating the negative electrode sheet.

10. A battery, characterized in that: The invention comprises a housing and the battery core according to any one of claims 1 to 9, wherein the battery core is accommodated in the housing.

Images