Battery cell pole piece structure, battery cell and battery

Abstract

The utility model belongs to the technical field of batteries, and particularly relates to a battery cell pole piece structure, a battery cell and a battery. The battery cell pole piece structure comprises a pole piece body and a bonding filling component, a first groove is formed in at least one surface of the pole piece body; the bonding and filling part comprises a filling part and a covering part which are connected with each other; the filling part is connected to the interior of the first groove; and the covering part is connected to the opening of the first groove. According to the utility model, the problem of non-uniform stress during formation of the tab position can be improved, so that the lithium precipitation risk of a battery cell is reduced, and the use safety and stability are improved.

Description

Technical Field

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

[0002] Lithium-ion batteries, with their high energy density, high output power, long charge-discharge life, and low self-discharge, are widely used in applications such as portable consumer electronics and power tools. In recent years, the fast-paced lifestyle has led to increasingly stringent requirements for battery charging times, demanding cell structures with lower internal resistance. Based on this, a structure with a slot in the middle of the electrode sheet has been developed, allowing the tab to be welded to the center of the electrode sheet. This structure significantly reduces the internal resistance of the cell and increases the charge and discharge speed.

[0003] However, the aforementioned structure can result in significant local thickness differences at the groove locations, which can lead to poor electrode thickness consistency. This can cause uneven stress in some areas of the cell during the formation process, resulting in larger electrode gaps in defective areas. This can lead to poor interfacial wetting in the later stages of cell cycling, causing lithium deposition and accelerated capacity decay, thus reducing safety and stability. Utility Model Content

[0004] The purpose of the present invention is to provide a battery cell electrode structure to address the deficiencies in the prior art and to solve the above-mentioned technical problems of poor safety and stability in use.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A battery cell pole piece structure includes a pole piece body and an adhesive filling component; a first groove is provided on at least one surface of the pole piece body; the adhesive filling component includes a filling portion and a covering portion connected to each other; the filling portion is connected to the interior of the first groove; and the covering portion is connected to the opening of the first groove.

[0007] Preferably, the filling volume V1 of the filling portion is less than or equal to the volume V2 inside the first groove;

[0008] And / or, a projection area S1 of the covering portion toward the pole piece body is larger than an area S2 at the opening of the first groove.

[0009] Preferably, the relationship between the filling depth T2 of the filling portion and the depth T3 of the first groove satisfies: T2≤T3;

[0010] And / or, a filling depth T2 of the filling portion satisfies: 20 um ≤ T2 ≤ 120 um; and / or, a depth T3 of the first groove satisfies: 30 um ≤ T3 ≤ 120 um.

[0011] Preferably, the relationship between the filling width W1 of the filling portion, the width W2 inside the first groove, and the width W3 of the covering portion satisfies: W1≤W2<W3;

[0012] And / or, the relationship between the width W2 of the interior of the first groove and the width W3 of the covering portion satisfies: W3 = W2 + (2 mm to 20 mm);

[0013] And / or, a filling width W1 of the filling portion satisfies: 5 mm ≤ W1 ≤ 19 mm; and / or, a width W2 inside the first groove satisfies: 6 mm ≤ W2 ≤ 20 mm.

[0014] Preferably, the thickness T1 of the covering portion satisfies: 5um≤T1≤40um.

[0015] Preferably: the pole piece body includes a current collector and active material layers connected to both side surfaces of the current collector; the first groove is provided on one of the active material layers; and the first groove is provided throughout the thickness direction of the one of the active material layers.

[0016] Preferably: a second groove is further provided on the pole piece body; the second groove is provided on the other active material layer; and the second groove and the first groove are provided on both side surfaces of the current collector opposite to each other; and a pole ear body is fixed inside the second groove; and an adhesive separation component is provided at the opening of the second groove.

[0017] The utility model also discloses a battery cell, comprising a first pole piece, an isolation membrane and a second pole piece stacked in sequence; the first pole piece and / or the second pole piece is the battery cell pole piece structure described above.

[0018] Preferably, the first electrode piece has corresponding first and second grooves on both side surfaces; a second electrode piece adjacent to the first electrode piece has a corresponding third groove on one side surface; the opening of the third groove of the second electrode piece is arranged toward the opening of the second groove of the first electrode piece; the first electrode piece is a positive electrode piece, and the second electrode piece is a negative electrode piece;

[0019] Among them, on the second pole piece, the opening width W of the third groove 11 ; and in the first pole piece, the relationship between the opening width W1 of the first groove satisfies: W 11 <W1;

[0020] And / or, on the second pole piece, the relationship between the width L2 of the covering portion at the opening of the third groove; and in the first pole piece, the width L1 of the covering portion at the opening of the first groove satisfies: L2<L1; and 2mm≤L2≤20mm; 2mm≤L1≤20mm.

[0021] The utility model also discloses a battery, comprising the battery core.

[0022] The beneficial effect of the present invention is that the technical solution can effectively ensure that the thickness of the first groove is as consistent as possible with the thickness of other positions of the pole piece body by adopting the filling part to fill and assemble into the interior of the first groove, thereby improving the flatness of the first groove and improving the problem of uneven force during the formation of the pole ear position, thereby reducing the risk of lithium plating in the battery cell and improving the safety and stability of use; in addition, the covering effect of the covering part is used to achieve the separation effect of the empty foil metal area at the first groove, and the stability of the overall assembly is achieved through its stable bonding effect, thereby improving the safety and stability of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The following will refer to the attached Figures 1 to 5 To describe the features, advantages and technical effects of exemplary embodiments of the present invention.

[0024] Figure 1 This is a schematic structural diagram of a battery cell electrode structure according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic structural diagram of a battery cell electrode structure according to an embodiment of the present invention;

[0026] Figure 3 This is a schematic structural diagram of a battery cell electrode structure according to an embodiment of the present invention;

[0027] Figure 4 This is a schematic structural diagram of a battery cell electrode structure according to an embodiment of the present invention;

[0028] Figure 5 This is a schematic structural diagram of a battery cell according to an embodiment of the present invention.

[0029] In the figure: 1-pole body; 11-active material layer; 12-current collector; 101-first groove; 102-second groove; 103-third groove; 3-bonding filling component; 31-filling part; 32-covering part; 2-ear body; 4-bonding separator; 100-first pole piece; 200-second pole piece; 300-isolating membrane. DETAILED DESCRIPTION

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0031] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0032] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0033] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or multiple situations exist. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0034] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0035] The following is combined with Figures 1 to 5 The present invention is further described in detail, but is not intended to limit the present invention.

[0036] like Figure 1 As shown, in one embodiment of the present invention, the battery cell electrode structure includes a electrode body 1 and a bonding filling component 3; at least one surface of the electrode body 1 is provided with a first groove 101; the bonding filling component 3 includes a filling portion 31 and a covering portion 32 connected to each other; the filling portion 31 fills and connects to the inside of the first groove 101; the covering portion 32 covers and connects to the opening of the first groove 101.

[0037] The technical solution of the present invention adopts the filling part to fill and assemble into the interior of the first groove, which can effectively ensure that the thickness of the first groove is as consistent as possible with the thickness of other positions of the electrode body, thereby improving the flatness of the first groove and improving the problem of uneven force during the formation of the electrode position, thereby reducing the risk of lithium plating in the battery cell and improving the safety and stability of use; in addition, the covering effect of the covering part is used to achieve the separation effect of the empty foil metal area in the first groove, and the stability of the overall assembly is achieved through its stable bonding effect, thereby improving the safety and stability of use.

[0038] The bonding filler 3 can be a green glue or other similar bonding filler. This structure ensures bonding stability and filling integrity, improves the flatness of the area, alleviates uneven force on the tab during formation, and reduces the risk of lithium plating in the battery cell.

[0039] Specifically, in some embodiments, Figure 1 and 2 As shown, the filling volume V1 of the filling portion 31 is less than or equal to the volume V2 within the first groove 101; and the projected area S1 of the covering portion 32 toward the pole piece body 1 is greater than or equal to the area S2 at the opening of the first groove 101. Preferably, the projected area S1 of the covering portion 32 toward the pole piece body 1 is greater than the area S2 at the opening of the first groove 101. In other words, the T-shaped or L-shaped structure formed by the filling portion 31 and the covering portion 32 can ensure the filling stability of the first groove 101 and the stability of the assembly. In addition, it can also reduce the number of glue applications, thereby reducing the difficulty of glue application equipment and improving glue application efficiency.

[0040] Specifically, in some embodiments, Figure 2 and 3 As shown, the relationship between the filling depth T2 of the filling portion 31 and the depth T3 of the first groove 101 satisfies: T2≤T3. Among them, the filling depth T2 of the filling portion 31 satisfies: 20um≤T2≤120um; the depth T3 of the first groove 101 satisfies: 30um≤T3≤120um. This structure can ensure the convenience of filling and the stability of filling through the filling portion 31 and the first groove 101 with appropriate parameter values, so it is beneficial to ensure the thickness consistency between the first groove and the main area; improve the unevenness problem between the first groove and the main area, and reduce the risk of lithium plating.

[0041] Specifically, in some embodiments, Figure 2 and 4As shown, the relationship between the filling width W1 of the filling part 31, the width W2 inside the first groove 101 and the width W3 of the covering part 32 satisfies: W1≤W2<W3. Among them, the filling width W1 of the filling part 31 satisfies: 5mm≤W1≤19mm; the width W2 inside the first groove 101 satisfies: 6mm≤W2≤20mm; the relationship between the width W2 inside the first groove 101 and the width W3 of the covering part 32 satisfies: W3=W2+(2mm~20mm). This structure can ensure the convenience of filling and the stability of filling by taking appropriate parameter values ​​for the filling part 31, the first groove 101 and the covering part 32, so it is beneficial to ensure the thickness consistency between the first groove and the main area; improve the unevenness problem between the first groove and the main area, and reduce the risk of lithium plating.

[0042] Specifically, in some embodiments, Figure 3 As shown, the thickness T1 of the cover portion 32 satisfies the following conditions: 5 ≤ T1 ≤ 40 μm. This structure ensures convenient and stable filling through the cover portion 32 with appropriate parameter values, thereby ensuring thickness consistency between the first groove and the main body area, improving the unevenness between the first groove and the main body area, and reducing the risk of lithium plating.

[0043] Specifically, in some embodiments, Figure 1 As shown, the electrode body 1 includes a current collector 12 and active material layers 11 connected to both sides of the current collector 12. The first groove 101 is provided on one side of the active material layer 11, and the first groove 101 extends through the thickness of the active material layer 11. In other words, the active material layer 11 at the first groove 101 is completely cleaned to expose the current collector, which can improve the orderliness of the cleaning process.

[0044] Specifically, in some embodiments, Figure 1 and 2 As shown, the electrode body 1 is further provided with a second groove 102; the second groove 102 is provided on the other active material layer 11; and the second groove 102 and the first groove 101 are provided on both sides of the current collector 12. The electrode tab 2 is fixed inside the second groove 102; and an adhesive separator 4 is provided at the opening of the second groove 102. The adhesive separator 4 can be a green glue or other adhesive separator with the same function. The projected area of ​​the adhesive separator 4 toward the current collector 12 is larger than the projected area of ​​the first groove 101 toward the current collector 12.

[0045] That is, when the pole piece body 1 is used in the lamination process or the winding process and the tab body is not present in the pole piece body 1, one side surface of the pole piece body 1 is provided with only the first groove 101 and the adhesive filling component 3, without the second groove 102. When the pole piece body 1 is used in the lamination process or the winding process and has the tab body 2, the second groove 102 needs to be added, and the second groove 102 is arranged opposite the first groove 101. That is, the adhesive filling component 3 is connected to the interior of the first groove 101 where the tab body 2 is not installed; and the adhesive separation component 4 is connected to the interior of the second groove 102 where the tab body 2 is installed.

[0046] The present invention also provides a battery cell, such as Figure 5 As shown, the battery cell includes a first electrode piece 100, an isolation membrane 300 and a second electrode piece 200 which are stacked in sequence; the first electrode piece 100 and / or the second electrode piece 200 are a battery cell electrode piece structure; both side surfaces of the first electrode piece 100 have corresponding first grooves 101 and second grooves 102; one side surface of the second electrode piece 200 adjacent to the first electrode piece 100 has only a corresponding third groove 103; the opening of the third groove 103 of the second electrode piece 200 is arranged toward the opening of the second groove 102 of the first electrode piece 100; the first electrode piece 100 is a positive electrode piece, and the second electrode piece 200 is a negative electrode piece.

[0047] Among them, Figure 5 As shown, in the second pole piece 200, the opening width W of the third groove 103 is 11 ; and in the first pole piece 100, the relationship between the opening width W1 of the first groove 101 satisfies: W 11 <W1; further, in the second pole piece 200, the width L2 of the covering portion 32 at the opening of the third groove 101; and in the first pole piece 100, the relationship between the width L1 of the covering portion 32 at the opening of the first groove 101 satisfies: L2<L1; and 2mm≤L2≤20mm; 2mm≤L1≤20mm.

[0048] The specific structure of the battery cell electrode structure refers to the above embodiments. Since this battery cell adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0049] The positive electrode current collector can be made of aluminum, and the positive electrode active material layer includes a positive electrode active material such as lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode current collector can be made of copper, and the negative electrode active material layer includes a negative electrode active material such as carbon or silicon. The separator 300 can be made of PP (polypropylene) or PE (polyethylene).

[0050] The present invention also provides a battery, which includes a battery cell. The specific structure of the battery cell refers to the above embodiments. Since the battery adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0051] A battery refers to a cup, tank, or other container, or a portion of a composite container, that contains an electrolyte solution and metal electrodes to generate an electric current. It is a device capable of converting chemical energy into electrical energy. Batteries have positive and negative electrodes. With technological advancements, batteries have become a general term for small devices that can generate electrical energy, such as solar cells. Key battery performance parameters include electromotive force, capacity, specific energy, and resistance. Battery Principle: In chemical batteries, the direct conversion of chemical energy into electrical energy occurs through spontaneous chemical reactions within the battery, such as oxidation and reduction, which occur at the two electrodes. The negative electrode active material consists of a reducing agent with a relatively negative potential and is stable in the electrolyte, such as active metals like zinc, cadmium, and lead, and hydrogen or hydrocarbons. The positive electrode active material consists of an oxidizing agent with a relatively positive potential and is stable in the electrolyte, such as metal oxides like manganese dioxide, lead dioxide, and nickel oxide, oxygen or air, halogens and their salts, and oxygen-containing acids and their salts. The electrolyte is a material with good ionic conductivity, such as aqueous solutions of acids, bases, and salts, organic or inorganic non-aqueous solutions, molten salts, or solid electrolytes.

[0052] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0053] Based on the disclosure and teachings of the above description, those skilled in the art will be able to make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments described above. Any obvious improvements, substitutions, or modifications made by those skilled in the art based on the present invention fall within the scope of protection of the present invention. In addition, although certain specific terms are used in this description, these terms are for convenience only and do not constitute any limitation on the present invention.

Claims

1. A battery cell electrode structure, characterized by: It includes a pole piece body and an adhesive filling component; a first groove is provided on at least one surface of the pole piece body; the adhesive filling component includes a filling part and a covering part connected to each other; the filling part is connected to the inside of the first groove; the covering part is connected to the opening of the first groove.

2. The battery cell electrode structure according to claim 1, characterized in that: The filling volume V1 of the filling portion is less than or equal to the volume V2 inside the first groove; And / or, a projection area S1 of the covering portion toward the pole piece body is larger than an area S2 at the opening of the first groove.

3. The battery cell electrode structure according to claim 1, characterized in that: The relationship between the filling depth T2 of the filling portion and the depth T3 of the first groove satisfies: T2≤T3; And / or, a filling depth T2 of the filling portion satisfies: 20 um ≤ T2 ≤ 120 um; and / or, a depth T3 of the first groove satisfies: 30 um ≤ T3 ≤ 120 um.

4. The battery cell electrode structure according to claim 1, characterized in that: The relationship between the filling width W1 of the filling portion, the width W2 inside the first groove, and the width W3 of the covering portion satisfies: W1≤W2<W3; And / or, the relationship between the width W2 of the interior of the first groove and the width W3 of the covering portion satisfies: W3 = W2 + (2 mm to 20 mm); And / or, a filling width W1 of the filling portion satisfies: 5 mm ≤ W1 ≤ 19 mm; and / or, a width W2 inside the first groove satisfies: 6 mm ≤ W2 ≤ 20 mm.

5. The battery cell electrode structure according to claim 1, characterized in that: The thickness T1 of the covering portion satisfies: 5 μm≤T1≤40 μm.

6. The battery cell electrode structure according to any one of claims 1 to 5, characterized in that: The pole piece body includes a current collector and active material layers connected to both side surfaces of the current collector; the first groove is arranged on one of the active material layers; and the first groove is arranged throughout the thickness direction of the one of the active material layers.

7. The battery cell electrode structure according to claim 6, characterized in that: A second groove is also provided on the pole piece body; the second groove is provided on the other active material layer; and the second groove and the first groove are provided on both side surfaces of the current collector opposite to each other; and a pole ear body is fixed inside the second groove; and an adhesive separation component is provided at the opening of the second groove.

8. A battery cell, characterized in that: It comprises a first pole piece, an isolation membrane and a second pole piece which are stacked in sequence; the first pole piece and / or the second pole piece is the battery cell pole piece structure as described in claims 1 to 7 above.

9. The battery cell according to claim 8, characterized in that: The first pole piece has corresponding first and second grooves on both sides of the pole piece; a second pole piece adjacent to the first pole piece has a corresponding third groove on one side of the pole piece; the opening of the third groove of the second pole piece is arranged toward the opening of the second groove of the first pole piece; The first electrode is a positive electrode, and the second electrode is a negative electrode; Among them, on the second pole piece, the opening width W of the third groove 11 ; And in the first pole piece, the relationship between the opening width W1 of the first groove satisfies: W 11 <W1; And / or, on the second pole piece, the relationship between the width L2 of the covering portion at the opening of the third groove; and in the first pole piece, the width L1 of the covering portion at the opening of the first groove satisfies: L2<L1; and 2mm≤L2≤20mm; 2mm≤L1≤20mm.

10. A battery, characterized in that: Including the battery cell according to claim 8 or 9.

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