Battery cell, battery and battery module

Abstract

The utility model relates to battery technology field discloses a kind of battery cell, battery and battery module, the battery cell includes pole piece and isolation film, the isolation film isolation between two pole pieces, including isolation film main body, the isolation film main body includes two surfaces oppositely arranged, and at least one the periphery of surface is equipped with anti-shrinkage layer, the anti-shrinkage layer and the isolation film main body are enclosed into a containing area containing the pole piece. The utility model can improve the thermal stability of isolation film main body by setting anti-shrinkage layer on the periphery of at least one surface of isolation film main body, to realize the shrinkage of isolation film in the process of inhibition under heat. At the same time, as an accommodation area is enclosed between the anti-shrinkage layer and the isolation film main body, the pole piece is accommodated in the accommodation area, so that the isolation film main body always has a separating effect on the positive and negative pole pieces of the battery, avoiding short circuit caused by the contact of the positive and negative poles of the battery, and ensuring the safety performance of the battery.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery cell, battery and battery module. Background Technology

[0002] In lithium-ion batteries, the separator is one of the key inner components. Its main function is to separate the positive and negative electrodes of the battery and prevent the two electrodes from coming into contact and short-circuiting. Therefore, the performance of the separator directly determines the safety performance of the battery.

[0003] However, in existing stacked batteries, when the temperature rises to a certain value (usually 120 degrees Celsius), the separator in the cell will shrink, causing large-area contact between the positive and negative electrodes, which will lead to a short circuit in the cell and cause battery failure. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a battery cell, a battery, and a battery module that suppresses the shrinkage of the separator during the heating process, thereby avoiding short circuits caused by contact between the positive and negative electrodes of the battery and ensuring the safety performance of the battery.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] A laminated battery cell, comprising:

[0007] Electrode;

[0008] A separator is provided between two electrodes. The separator includes a separator body with two opposing surfaces. At least one of the surfaces has a shrinkage-resistant layer around its periphery. The shrinkage-resistant layer and the separator body form a receiving area, and the electrodes are received within the receiving area.

[0009] Preferably, the thickness of the shrinkage-resistant layer is 2–20 μm.

[0010] Preferably, the width of the anti-shrinkage layer is B, and the value of B ranges from 2 to 20 μm.

[0011] Preferably, the shrinkage-resistant layer is made of ceramic or high-temperature resistant adhesive.

[0012] Preferably, there are multiple isolation membrane bodies, which are arranged in a row, and adjacent isolation membrane bodies are connected by a connecting membrane.

[0013] Each pair of adjacent separator membrane bodies is folded along the position of the connecting membrane, and an electrode is provided between any two adjacent separator membrane bodies.

[0014] Preferably, the isolation membrane body is rectangular, including two first sides disposed opposite each other and two second sides connecting the two first sides;

[0015] The corresponding first sides of two adjacent isolation membrane bodies are connected by the connecting membrane.

[0016] Preferably, the surface on the main body of the isolation membrane where the anti-shrinkage layer is provided is defined as the anti-shrinkage surface;

[0017] The electrode is attached to the center of the anti-shrinkage surface, and the distance between the outer periphery of the electrode and the outer periphery of the anti-shrinkage surface is L, with L ranging from 2 to 20 μm.

[0018] Preferably, the electrode includes a positive electrode and a negative electrode;

[0019] The anti-shrinkage layer is only disposed on the surface of the separator body corresponding to the positive electrode sheet.

[0020] A battery comprising the aforementioned battery cell.

[0021] A battery module comprising the aforementioned battery.

[0022] The battery cell, battery, and battery module of this application embodiment have the following advantages compared with the prior art: By providing an anti-shrinkage layer on the periphery of at least one surface of the separator body, the thermal stability of the separator body can be improved, thereby suppressing the shrinkage of the separator during heating. Simultaneously, since the anti-shrinkage layer and the separator body form a receiving area, and the electrode is received within this area, the separator body always effectively separates the positive and negative electrode sheets of the battery, preventing short circuits caused by contact between the positive and negative electrodes and ensuring the safety performance of the battery. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the battery cell structure according to Embodiment 1 of this utility model.

[0024] Figure 2 This is a schematic diagram of the structure of the separator and electrode of this utility model.

[0025] Figure 3 This is a schematic diagram of the battery cell structure of Embodiment 2 of this utility model.

[0026] Figure 4 This is a schematic diagram of the structure of the isolation strip of this utility model.

[0027] Wherein: 1-positive electrode sheet, 2-negative electrode sheet, 3-positive electrode tab, 4-negative electrode tab, 5-separator, 51-separator body, 511-first side, 512-second side, 52-anti-shrinkage layer, 53-accommodating area, 6-separator strip, 61-first space, 62-second space, 63-first opening, 64-second opening, 65-connecting membrane, 100-cell, 101-horizontal part, 102-corner part. Detailed Implementation

[0028] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0029] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0030] Example 1

[0031] like Figure 1-2 As shown, a preferred embodiment of the present invention provides a laminated battery cell, comprising a positive electrode 1, a negative electrode 2, and a separator 5. The positive electrode 1 has a positive electrode tab 3, and the negative electrode 2 has a negative electrode tab 4. The positive electrode 1 and the negative electrode 2 are stacked sequentially, and the separator 5 is disposed between the positive electrode 1 and the negative electrode 2. That is, the battery cell 100 has a structure comprising a sequentially stacked positive electrode 1, separator 5, negative electrode 2, separator 5, positive electrode 1, ... structure, forming a laminated battery cell.

[0032] The separator 5 includes a separator body 51, which has two opposing surfaces (upper and lower surfaces). At least one of these surfaces has a shrinkage-resistant layer 52 around its periphery. The shrinkage-resistant layer 52 and the separator body 51 form a receiving area 53, within which the electrode is received. The shrinkage-resistant layer 52 is made of ceramic (alumina, boehmite, magnesium hydroxide, etc.) or high-temperature resistant adhesive. The shrinkage-resistant layer 52 must not affect the overall thickness of the battery cell 100. Therefore, the thickness of the shrinkage-resistant layer 52 can be set to be equal to or less than the thickness of the electrode, preferably 2–20 μm, such as 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, or any value or range between any two of the above values.

[0033] In this embodiment, the width of the anti-shrinkage layer 52 is B, and the value of B ranges from 2 to 20 μm, such as 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, etc., or any value or range between any two of the above values.

[0034] For ease of description, the surface on the separator membrane body 51 where the anti-shrinkage layer 52 is located is defined as the anti-shrinkage surface. The electrode is attached to the center of the anti-shrinkage surface, and the distance between the outer periphery of the electrode and the outer periphery of the anti-shrinkage surface is consistent and L. That is, the electrode and the separator membrane body 51 have the same shape, and the distance between each side of the electrode and the corresponding side of the separator membrane body 51 is L. Preferably, the value of L is in the range of 2 to 20 μm, such as 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, etc., or any value or range between any two of the above values.

[0035] However, during the manufacturing process of the battery cell 100, in order to adapt to the working principle of lithium-ion batteries and avoid lithium plating during charging, the width of the negative electrode 2 usually needs to be designed to be 1-4 mm larger than the width of the positive electrode 1. Therefore, when setting it, the anti-shrinkage layer is preferably set on the surface of the separator body 51 corresponding to the positive electrode 1, which can minimize the impact of the anti-shrinkage layer 52 on the adhesion between the electrode and the separator body 51.

[0036] However, considering the actual design of the negative electrode 2 edge exceeding the positive electrode edge 1, when setting the positive electrode 1, the value of L is preferably greater than the value of B. That is, there is a gap between the positive electrode 1 and the anti-shrinkage layer 52, thereby ensuring that the size of the separator body 51 can perfectly match the negative electrode 2, so that the separator body 51 can always separate the positive and negative electrodes of the battery. Therefore, L is preferably 2~10um, and B is preferably 1~5um.

[0037] As described above, the anti-shrinkage layer 52 is typically applied to the surface that adheres to the positive electrode 1. However, if coating is applied only on one side, the shrinkage improvement is poor, so double-sided coating can be performed. In this case, the width of the anti-shrinkage layer 52 on the surface of the separator body 51 that adheres to the negative electrode 2 can be appropriately reduced to ensure that the negative electrode 2 is accommodated within the accommodating area 53.

[0038] Example 2

[0039] like Figure 3-4 As shown, the difference between this embodiment and Embodiment 1 is that the isolation membrane bodies 51 are not separate but connected as a whole.

[0040] Specifically, there are multiple separator membrane bodies 51 arranged in a row, and adjacent separator membrane bodies 51 are connected by a connecting membrane 65 to form a separator strip 6. Each pair of adjacent separator membrane bodies is folded along the position of the connecting membrane, and an electrode is provided between any two adjacent separator membrane bodies. The separator membrane bodies can be rectangular or irregular in shape, and their stacking method is the same. The following description uses a rectangular shape as an example.

[0041] The separator body 51 is rectangular, including two first sides 511 arranged opposite each other and two second sides 512 connecting the two first sides 511. The corresponding first sides 511 of two adjacent separator bodies 51 are connected by the connecting membrane 65. The separator strip 6 is folded continuously in a Z-shape so that the separator body 51 and the connecting membrane 65 form an alternating first space 61 and a second space 62. The first space 61 has a first opening 63, and the second space 62 has a second opening 64. The first opening 63 and the second opening 64 are offset and arranged opposite each other. The positive electrode 1 is inserted into the first space 61 through the first opening 63, and the negative electrode 2 is inserted into the second space 62 through the second opening 64, thereby forming a folded laminated cell. That is, the battery cell 100 forms a horizontal portion 101 (large surface) and a corner portion 102, and each two adjacent separator bodies 51 are folded along the position of the connecting film 65, so that the connecting film 65 forms the corner portion 102 and the separator body 51 forms the horizontal portion 101.

[0042] Based on the above-mentioned technical features, the battery cell improves the thermal stability of the separator body 51 by providing an anti-shrinkage layer 52 on the periphery of at least one surface of the separator body 51, thereby suppressing the shrinkage of the separator 51 during heating. Simultaneously, since the anti-shrinkage layer 52 and the separator body 51 enclose a receiving area 53, and the electrode is received within the receiving area 53, the separator body 51 always effectively separates the positive and negative electrode sheets of the battery, preventing short circuits caused by contact between the positive and negative electrodes and ensuring the battery's safety performance.

[0043] To address the aforementioned technical problems, this application also provides a battery module, which includes a battery, and the battery includes the aforementioned cell 100. This battery module can prevent short circuits caused by contact between the positive and negative terminals of the cell 100, thereby ensuring the safety performance of the battery.

[0044] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A laminated battery cell, characterized in that: include: Electrode; A separator is provided between two electrodes. The separator includes a separator body with two opposing surfaces. At least one of the surfaces has a shrinkage-resistant layer around its periphery. The shrinkage-resistant layer and the separator body form a receiving area, and the electrodes are received within the receiving area.

2. The laminated cell as described in claim 1, characterized in that: The thickness of the anti-shrinkage layer is 2–20 μm.

3. The laminated cell as described in claim 1, characterized in that: The width of the anti-shrinkage layer is B, and the value of B ranges from 2 to 20 μm.

4. The laminated cell as described in claim 1, characterized in that: The shrinkage-resistant layer is made of ceramic or high-temperature resistant adhesive.

5. The laminated cell as described in any one of claims 1-4, characterized in that: The isolation membrane body is a plurality of such bodies, which are arranged in a row and adjacent isolation membrane bodies are connected by a connecting membrane. Each pair of adjacent separator membrane bodies is folded along the position of the connecting membrane, and an electrode is provided between any two adjacent separator membrane bodies.

6. The laminated cell as described in claim 5, characterized in that: The main body of the isolation membrane is rectangular, including two first sides arranged opposite to each other and two second sides connecting the two first sides; The corresponding first sides of two adjacent isolation membrane bodies are connected by the connecting membrane.

7. The laminated cell according to any one of claims 1-4, characterized in that, The surface on the main body of the isolation membrane where the anti-shrinkage layer is provided is defined as the anti-shrinkage surface; The electrode is attached to the center of the anti-shrinkage surface, and the distance between the outer periphery of the electrode and the outer periphery of the anti-shrinkage surface is L, with L ranging from 2 to 20 μm.

8. The laminated cell according to any one of claims 1-4, characterized in that, The electrode includes a positive electrode and a negative electrode; The anti-shrinkage layer is only disposed on the surface of the separator body corresponding to the positive electrode sheet.

9. A battery, characterized in that: Including the battery cell as described in any one of claims 1-8.

10. A battery module, characterized in that: Includes the battery as described in claim 9.

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