Battery cell assembly, battery cell structure and battery

Abstract

A battery cell assembly, a battery cell structure and a battery. The battery cell assembly comprises a first electrode (100) and a second electrode (200), wherein the second electrode (200) and the first electrode (100) are stacked. The first electrode (100) comprises a first current collector (110), a first active coating (120), and a first support coating (130). In the direction of width of the first current collector (110), a first active material coating region (111), a support material coating region (112), and a first bare foil region (113) are provided in sequence on the first current collector (110); and in the direction of thickness of the first current collector (110), the first active coating (120) is arranged on both sides of the first current collector (110), the first support coating (130) is arranged in the support material coating region (112) of the first current collector (110), and the first support coating (130) is located on the inner side of the battery cell assembly. During the flattening process of the battery cell assembly, the first support coating (130) provides support for a first tab (114), thereby reducing the risk of short circuits caused by excessive bending of the first tab (114) towards the interior of the battery cell and subsequent contact with an opposing electrode.

Description

Battery cell assembly, battery cell structure and battery

[0001] Cross-reference to related applications

[0002] The present application is based on and claims priority to Chinese Patent Application No. 202422303839.4, filed on September 20, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of batteries, in particular to a battery cell assembly, a battery cell structure and a battery. BACKGROUND

[0004] With new requirements for high-rate charging and discharging of batteries for new energy vehicles and the like, conventional single-pole and double-pole structure batteries cannot meet the heat dissipation requirements of the batteries under large current charging and discharging conditions. Therefore, in the prior art, a full-pole design end face welding cylindrical battery has been developed. The full-pole structure battery greatly reduces the internal resistance of the battery, greatly improves the high-rate charging and discharging performance of the battery, reduces the heat generation efficiency of the battery during charging and discharging, and improves the thermal diffusion coefficient of the battery, thereby effectively improving the high-rate performance and safety performance of the battery. The electrode tab of the full-pole cylindrical battery is pressed inward by mechanical force through a rubbing process, and the deformation of the electrode foil part during the rubbing process is uncontrollable, which may cause the risk of excessive bending of the pole tab into the battery and short circuiting with the electrode. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a battery cell assembly, a battery cell structure and a battery. A support coating is coated on the electrode foil area of the battery cell assembly. During the rubbing process of the battery cell assembly, the support coating supports the pole tab, thereby reducing the risk of excessive bending of the pole tab into the battery and short circuiting with the electrode.

[0006] According to an embodiment of the present application, a battery cell assembly comprises:

[0007] A first electrode comprises a first current collector, a first active coating and a first support coating. The first current collector has a first active material coating area, a support material coating area and a first electrode foil area arranged in sequence along the width direction of the first current collector. The first active coating is arranged on both sides of the first current collector in the thickness direction of the first current collector and located in the first active material coating area. The first support coating is arranged on the first current collector and located in the support material coating area and on the inner side of the battery cell assembly. The first support coating supports the first current collector when the battery cell assembly is rubbed.

[0008] A second electrode is stacked with the first electrode;

[0009] Wherein, a plane parallel to the width direction of the first electrode is defined as a reference plane, the projection of the end of the second electrode close to the first empty foil area on the reference plane forms a line a, the projection of the end of the first support coating away from the first active coating on the reference plane forms a line b, the projection of the end of the first support coating close to the first active coating on the reference plane forms a line c, and the line a is located between the line b and the line c.

[0010] According to the battery cell assembly of the embodiments of the present application, at least the following beneficial effects are achieved:

[0011] The first support coating is arranged on the first current collector in the support coating area and on the inner side of the battery cell assembly. During the flattening process of the battery cell assembly (the electrode edge empty foil is bent towards the center of the roll core), the first support coating supports the tab (the first current collector of the first empty foil area) (extrapolates the tab), which can reduce the risk of excessive bending of the tab towards the inside of the battery cell and short circuiting with the opposite electrode.

[0012] According to some embodiments of the present application, the first electrode further comprises a second support coating, which is arranged on the first current collector in the support coating area and on the outer side of the battery cell assembly.

[0013] According to some embodiments of the present application, the width of the first support coating is greater than the width of the second support coating, and the second support coating is arranged adjacent to the first active coating.

[0014] According to some embodiments of the present application, the width of the first support coating is 2-5 mm greater than the width of the second support coating.

[0015] According to some embodiments of the present application, the second electrode comprises a second current collector and a second active coating, the second current collector has a second active material coating area and a second empty foil area arranged in sequence along the width direction of the second current collector, and the second active coating is arranged on the second current collector in the second active material coating area and on both sides of the second current collector along the thickness direction of the second current collector;

[0016] The projection of the end of the first electrode close to the second empty foil area on the reference plane forms a line d, the projection of the end of the second active coating close to the second empty foil area on the reference plane forms a line e, and the line e is located on the side away from the center of the battery cell assembly of the line d.

[0017] According to some embodiments of the present application, the width of the second active coating is 2-5 mm greater than the width of the first active coating.

[0018] According to some embodiments of the present application, the first support coating layer comprises a combination of at least two of ceramic, polyacrylic, PVDF, CMC, and SBR.

[0019] According to some embodiments of the present application, the cell assembly is provided with a central hole.

[0020] According to an embodiment of the present application, a cell structure is formed by the cell assembly, and the first current collector of the first empty foil area is arranged in a bent manner relative to the first current collector of the first active material coating area.

[0021] According to an embodiment of the present application, a battery has at least the following beneficial effects:

[0022] A first support coating layer is arranged on the first current collector at the support coating area and on the inner side of the cell assembly. During the flattening process of the cell assembly (the electrode edge empty foil is bent towards the center of the roll core), the first support coating layer supports the tab, which can reduce the risk of excessive bending of the tab towards the inside of the cell and short circuiting of the electrode.

[0023] According to an embodiment of the present application, a battery comprises a housing and the cell structure, and the cell structure is located inside the housing.

[0024] According to an embodiment of the present application, a battery has at least the following beneficial effects:

[0025] A first support coating layer is arranged on the first current collector at the support coating area and on the inner side of the cell assembly. During the flattening process of the cell assembly (the electrode edge empty foil is bent towards the center of the roll core), the first support coating layer supports the tab, which can reduce the risk of excessive bending of the tab towards the inside of the cell and short circuiting of the electrode.

[0026] Additional aspects and advantages of the present application will be given in part in the following description. BRIEF DESCRIPTION OF DRAWINGS

[0027] The present application will be further described below in conjunction with the accompanying drawings and embodiments, in which:

[0028] FIG. 1 is a structural schematic view of a cell assembly according to an embodiment of the present application;

[0029] FIG. 2 is a sectional view of the cell assembly according to an embodiment of the present application;

[0030] FIG. 3 is a top view of a first electrode of the cell assembly according to an embodiment of the present application;

[0031] FIG. 4 is a sectional view of the first electrode of the cell assembly according to an embodiment of the present application;

[0032] FIG. 5 is a top view of a second electrode of the cell assembly according to an embodiment of the present application;

[0033] Fig. 6 is a sectional view of a second electrode of an electrode assembly according to an embodiment of the present application;

[0034] Fig. 7 is a sectional view of a first electrode of an electrode structure according to an embodiment of the present application.

[0035] Reference numerals: 100, first electrode; 110, first current collector; 111, first active material coating region; 112, support material coating region; 113, first empty foil region; 114, first tab; 120, first active material coating layer; 130, first support material coating layer; 140, second support material coating layer; 200, second electrode; 210, second current collector; 211, second active material coating region; 212, second empty foil region; 213, second tab; 220, second active material coating layer; 300, separator; 400, center hole; A, reference plane, a, line formed by projection of one end of the second electrode close to the first empty foil region on the reference plane; b, line formed by projection of one end of the first support material coating layer away from the first active material coating layer on the reference plane; c, line formed by projection of one end of the first support material coating layer close to the first active material coating layer on the reference plane; d, line formed by projection of one end of the first electrode close to the second empty foil region on the reference plane; e, line formed by projection of one end of the second active material coating layer close to the second empty foil region on the reference plane. DETAILED DESCRIPTION

[0036] Embodiments of the present application are described in detail below with reference to the attached drawings, wherein like or similar elements are denoted by the same or similar reference numerals throughout the drawings. The embodiments described below are examples for explaining the present application, and are not intended to limit the present application.

[0037] In the description of the present application, it is to be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are merely for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0038] In the description of the present application, it should be noted that unless specifically stated and limited otherwise, the terms "mounting", "connection", "connecting" should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium, or can be the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] Please refer to FIG. 1, FIG. 2 and FIG. 3, an electrode assembly of an embodiment of the present application includes a first electrode 100, a second electrode 200 and a separator 300. The first electrode 100 includes a first current collector 110, a first active coating 120 and a first support coating 130, the first current collector 110 is provided with a first active material coating area 111, a support material coating area 112 and a first empty foil area 113 in sequence along the width direction of the first current collector 110. The first active coating 120 is provided on the first current collector 110 at both sides of the first active material coating area 111 along the thickness direction of the first current collector 110, and the first support coating 130 is provided on the first current collector 110 at the support material coating area 112 and at the inner side of the electrode assembly, the first support coating 130 is used to support the first current collector 110 when the electrode assembly is flattened. The part of the first current collector 110 at the empty foil area forms a first tab 114. The second electrode 200 is stacked with the first electrode 100, and the separator 300 is provided between the first electrode 100 and the second electrode 200.

[0040] A plane parallel to the width direction of the first electrode 100 is defined as a reference plane A, the projection of one end of the second electrode 200 close to the first empty foil area 113 on the reference plane A forms a line a, the projection of one end of the first support coating 130 away from the first active coating 120 on the reference plane A forms a line b, the projection of one end of the first support coating 130 close to the first active coating 120 (the joint of the first support coating 130 and the first active coating 120) on the reference plane A forms a line c, and the line a is located between the line b and the line c.

[0041] The line a is located on the side of the line c away from the center of the electrode assembly, so that when the first support coating 130 is not coated, the first tab 114 is prone to excessive bending towards the inside of the electrode during the flattening process of the electrode assembly (the edge empty foil of the electrode is bent towards the center of the roll core), and the risk of short circuit contact with the second electrode 200.

[0042] Line b is located on the side of line a away from the center of the battery cell assembly, and the first current collector 110 is provided with the first support coating 130 on the support coating area 112 and on the inner side of the battery cell assembly. During the flattening process of the battery cell assembly (the electrode edge empty foil is bent towards the center of the roll core), the first support coating 130 supports the first tab 114 (extrudes the first tab 114), which can reduce the risk of the first tab 114 excessively bending into the battery cell and contacting the second electrode 200.

[0043] In some embodiments, referring to FIGS. 2, 3 and 4, the first electrode 100 further comprises a second support coating 140 provided on the first current collector 110 on the support coating area 112 and on the outer side of the battery cell assembly. During the flattening process of the battery cell assembly (the electrode edge empty foil is bent towards the center of the roll core), the second support coating 140 can pull the first tab 114, reducing the risk of the first tab 114 excessively bending into the battery cell and contacting the second electrode 200.

[0044] In some embodiments, referring to FIGS. 2, 3 and 4, the width of the first support coating 130 is greater than the width of the second support coating 140, and the second support coating 140 is provided adjacent to the first active coating 120. During the flattening process of the battery cell assembly (the electrode edge empty foil is bent towards the center of the roll core), the first support coating 130 extrudes the first tab 114, and the second support coating 140 pulls the first tab 114. By utilizing the asymmetry of the stress on the tab during the flattening process, the first tab 114 is asymmetrically coated on both sides (the width of the first support coating 130 is greater than the width of the second support coating 140), and the extrusion force is greater than the pulling force, which regulates the bending angle of the tab during the flattening process of the whole tab, and reduces the risk of positive and negative short circuit of the battery caused by excessive insertion of the first tab 114 during random bending.

[0045] In some embodiments, referring to FIGS. 2, 3 and 4, the width of the first support coating 130 is greater than the width of the second support coating 140 by 2-5 mm. By utilizing the asymmetry of the stress on the tab during the flattening process, the first tab 114 is asymmetrically coated on both sides, which regulates the bending angle of the tab during the flattening process of the whole tab, and reduces the risk of positive and negative short circuit of the battery caused by excessive insertion of the first tab 114 during random bending.

[0046] In some embodiments, referring to FIG. 2, FIG. 5 and FIG. 6, the second electrode 200 includes a second current collector 210 and a second active coating 220, the second current collector 210 is provided with a second active material coating area 211 and a second empty foil area 212 along the width direction of the second current collector 210 in sequence, the second active coating 220 is provided on both sides of the second current collector 210 along the thickness direction of the second current collector 210 at the second active material coating area 211, and the width of the second active coating 220 is greater than the width of the first active coating 120. The part of the second current collector 210 at the second empty foil area 212 forms a second tab 213, and the first tab 114 and the second tab 213 are located at both ends of the electrode assembly along the axial direction of the electrode assembly.

[0047] The projection of the end of the first electrode 100 close to the second empty foil area 212 on the reference plane A forms a line d, and the projection of the end of the second active coating 220 close to the second empty foil area 212 on the reference plane forms a line e, and the line e is located on the side of the line d away from the center of the electrode assembly.

[0048] The line e is located on the side of the line d away from the center of the electrode assembly, so that a part of the second active coating 220 (between the line d and the line e) close to the end of the first electrode 100 close to the second empty foil area 212 overflows, and during the flattening process of the electrode assembly (the edge of the electrode is bent towards the center of the roll core), the second active coating 220 between the line d and the line e supports the second tab 213 (extrapolates and pulls the second tab 213), which can reduce the risk of the second tab 213 excessively bending towards the inside of the electrode and short-circuiting with the first electrode 100.

[0049] In some embodiments, referring to FIG. 2, FIG. 5 and FIG. 6, the width of the second active coating 220 is 2-5mm greater than the width of the first active coating 120.

[0050] The line e is located on the side of the line d away from the center of the electrode assembly, and the line a is located on the side of the line c away from the center of the electrode assembly, that is, the width of the second active coating 220 is greater than the width of the first active coating 120. Generally, the first electrode 100 is a positive electrode, and the second electrode 200 is a negative electrode, so that the width of the second active coating 220 on the negative electrode is greater than the width of the first active coating 120 on the positive electrode, so that the negative electrode can more effectively absorb and store lithium ions migrated from the positive electrode, reduce the accumulation of lithium ions on the surface of the negative electrode, and thus reduce the risk of lithium precipitation.

[0051] In some embodiments, referring to FIGS. 2 and 3, the first support coating 130 comprises a combination of at least two of ceramic, polyacrylic acid, PVDF, CMC, and SBR. The combination can be two, three, four, or five substances. The ceramic can improve the mechanical strength and stability of the electrode material, the polyacrylic acid can be used as a binder, the PVDF (Polyvinylidene Fluoride) is often used as a binder, the CMC (Carboxymethyl Cellulose) has the functions of thickener and binder, and the SBR (Styrene-Butadiene Rubber) is often used as a binder.

[0052] The second support coating 140 comprises a combination of at least two of ceramic, polyacrylic acid, PVDF, CMC, and SBR.

[0053] Referring to FIGS. 1 and 7, an electrode structure of an embodiment of the application is formed by rolling an electrode assembly, and the first current collector 110 in the first empty foil area 113 is arranged in a bent manner relative to the first current collector 110 in the first active material coating area 111.

[0054] The first support coating 130 is arranged on the first current collector 110 in the support coating area 112 and on the inner side of the electrode assembly, and in the process of rolling the electrode assembly (the electrode edge empty foil is bent towards the center of the roll core), the first support coating 130 supports the first tab 114, which can reduce the risk of the first tab 114 excessively bending towards the inside of the electrode and contacting the second electrode 200 to cause a short circuit.

[0055] Referring to FIGS. 1 and 2, the electrode assembly is provided with a center hole 400, so that the electrode assembly is easy to be rolled, and the electrode edge empty foil of the electrode assembly is easy to be bent towards the center hole 400.

[0056] Referring to FIGS. 1 and 7, a battery of an embodiment of the application comprises a shell and an electrode structure, and the electrode structure is located inside the shell.

[0057] The first support coating 130 is arranged on the first current collector 110 in the support coating area 112 and on the inner side of the electrode assembly, and in the process of rolling the electrode assembly (the electrode edge empty foil is bent towards the center of the roll core), the first support coating 130 supports the first tab 114, which can reduce the risk of the first tab 114 excessively bending towards the inside of the electrode and contacting the second electrode 200 to cause a short circuit.

[0058] In the description of the application, reference has been made to descriptive terms such as "one embodiment", "some embodiments", "an embodiment", "example", "specific example" or "some examples" etc. Such terminology means that a particular feature, structure, material or characteristic being described is included in at least one embodiment or example of the application. The illustrative appearances of such terminology in various places in the specification does not necessarily refer to the same embodiment or example. Moreover, it is appreciated that the specific features, structures, materials or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0059] Although embodiments of this application have been shown and described, it is to be understood that various modifications, substitutions, combinations, and variations can be made therein without departing from the spirit and scope of the application, which is defined by the appended claims and their equivalents.

Claims

1. An electric cell assembly, comprising: a first electrode, comprising a first current collector, a first active coating and a first support coating, the first current collector having a first active material coating region, a support material coating region and a first empty foil region arranged in sequence along a width direction of the first current collector, the first active material coating region being provided with the first active coating on both sides along a thickness direction of the first current collector, and the first support coating being provided on the support material coating region and located at an inner side of the electric cell assembly; a second electrode, arranged in a stack with the first electrode; wherein a plane parallel to the width direction of the first electrode is defined as a reference plane, a projection of one end of the second electrode close to the first empty foil region on the reference plane forms a line a, a projection of one end of the first support coating away from the first active coating on the reference plane forms a line b, and a projection of one end of the first support coating close to the first active coating on the reference plane forms a line c, the line a being located between the line b and the line c.

2. An electric cell assembly according to claim 1, wherein, The first electrode further comprises a second support coating, the second support coating being provided on the first current collector and located at an outer side of the electric cell assembly.

3. An electrical cell assembly according to claim 2, wherein, The width of the first support coating is greater than the width of the second support coating, and the second support coating is arranged adjacent to the first active coating.

4. An electrical cell assembly according to claim 3, wherein, The width of the first support coating is 2-5 mm greater than the width of the second support coating.

5. An electrical cell assembly according to claim 1 wherein, The second electrode comprises a second current collector and a second active coating, the second current collector having a second active material coating region and a second empty foil region arranged in sequence along a width direction of the second current collector, and the second current collector being provided with the second active coating on both sides along a thickness direction of the second current collector and located at the second active material coating region; a projection of one end of the first electrode close to the second empty foil region on the reference plane forms a line d, and a projection of one end of the second active coating close to the second empty foil region on the reference plane forms a line e, the line e being located on a side of the line d away from the center of the electric cell assembly.

6. An electrical cell assembly according to claim 5, wherein, The width of the second active coating is 2-5 mm greater than the width of the first active coating.

7. An electrical cell assembly according to claim 1 wherein, The first support coating comprises a combination of at least two of ceramic, polyacrylic acid, PVDF, CMC and SBR.

8. An electrical cell assembly according to claim 1 wherein, The electric cell assembly is provided with a center hole. 9.An electric cell structure formed by folding the electric cell assembly according to any one of claims 1-8, the first current collector of the first empty foil region being arranged in a fold relative to the first current collector of the first active material coating region. 10.A battery, comprising a shell and the electric cell structure according to claim 9, the electric cell structure being located inside the shell.

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