Battery cell structure, battery and electric device

Abstract

The utility model discloses a kind of electric core structure, battery and electric equipment, electric core structure includes shell, cover plate, first current collector and second current collector. Shell defines cavity and the opening communicating cavity. Cover plate is suitable for covering opening and connecting shell. First current collector is housed in cavity. Second current collector is housed in cavity and between cover plate and first current collector, second current collector and cover plate are bonded and laminated arrangement. Among them, the polarity of second current collector and first current collector is same, the tensile strength of second current collector is greater than the tensile strength of first current collector. The scheme can effectively prevent second current collector from tearing, avoid the situation that crack puncture diaphragm leads to short circuit, improve the crashworthiness of electric core, improve the security of electric core use, and guarantee the energy density and charge rate of electric core.

Description

Technical Field

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

[0002] Lithium-ion batteries possess advantages such as high energy density, small footprint, long cycle life, and low environmental pollution, leading to their increasingly widespread application in electric bicycles, communications, electric vehicles, power, and data centers. However, market demands for higher battery energy density and faster charging speeds are also rising, which conventional pouch batteries struggle to meet. Current technologies utilize steel-cased batteries for power supply. While steel-cased batteries reduce the space wasted at the top edge and folds, thus increasing volumetric energy density, they suffer from lower charging rates, impacting user experience.

[0003] In related technologies, a laminated cell structure is used to reduce impedance and improve charging rate. The laminated cell structure includes a laminated core and a steel shell. The laminated core is housed in the steel shell and bonded to the shell's cover plate with hot melt adhesive. The steel shell cell is relatively heavy. During mechanical reliability testing (such as directional drop testing), repeated impacts and pulls can cause the electrodes bonded with hot melt adhesive to tear. The tears can easily puncture the separator, leading to a short circuit. Furthermore, after the electrodes tear, the binding effect of the hot melt adhesive on the laminated core weakens, causing the laminated core to move within the steel shell, potentially breaking welds or causing the electrodes to bend and short circuit. In other words, the impact resistance of the steel shell laminated cell is poor. Utility Model Content

[0004] The main purpose of this utility model is to propose a cell structure, battery and electrical equipment, which aims to solve the technical problem of poor impact resistance of steel-cased laminated cells.

[0005] To achieve the above objectives, a first aspect of this utility model provides a battery cell structure, comprising:

[0006] A housing that defines a cavity and an opening communicating with the cavity;

[0007] A cover plate, adapted to cover the opening and connect to the housing;

[0008] The first fluid collector is contained within the cavity;

[0009] The second current collector is housed in the cavity and located between the cover plate and the first current collector. The second current collector is bonded to the cover plate and arranged in a stacked manner.

[0010] The second current collector has the same polarity as the first current collector, and the tensile strength of the second current collector is greater than that of the first current collector.

[0011] In some embodiments, the cell structure includes a third current collector, which is housed in the cavity and located between the first current collector and the second current collector;

[0012] The polarity of the third current collector is the same as that of the first current collector, and the tensile strength of the second current collector is greater than that of the third current collector.

[0013] In some embodiments, the tensile strength of the first current collector is K1, wherein K1 satisfies: K1≥300MPa;

[0014] And / or,

[0015] The tensile strength of the second current collector is K2, where K2 satisfies: K2≥400MPa.

[0016] In some embodiments, the second current collector has the same grain size as the first current collector, and the thickness of the second current collector is greater than the thickness of the first current collector, so that the tensile strength of the second current collector is greater than the tensile strength of the first current collector.

[0017] In some embodiments, the thickness of the first current collector is H1, and the thickness of the second current collector is H2, wherein H1 and H2 satisfy the condition: 1 < H2 / H1 ≤ 7.

[0018] In some embodiments, the thickness of the first current collector is H1, wherein H1 satisfies: 4μm ≤ H1 ≤ 12μm; and / or,

[0019] The thickness of the second current collector is H2, wherein H2 satisfies: 4μm≤H2≤25μm.

[0020] In some embodiments, the thickness of the second current collector is equal to that of the first current collector, and the grain size of the second current collector is smaller than that of the first current collector, so that the tensile strength of the second current collector is greater than that of the first current collector.

[0021] In some embodiments, the cell structure includes a fourth current collector, a first diaphragm, and a second diaphragm located within the cavity, wherein the fourth current collector is located between the first current collector and the second current collector;

[0022] The polarity of the fourth current collector is different from that of the first current collector, the first diaphragm is located between the fourth current collector and the first current collector, and the second diaphragm is located between the fourth current collector and the second current collector.

[0023] A second aspect of this utility model provides a battery comprising the cell structure described in the above embodiments.

[0024] A third aspect of this utility model provides an electrical device including a battery as described in the above embodiments.

[0025] Compared with the prior art, the beneficial effects of this utility model include:

[0026] In this invention, the cell structure includes a housing, a cover plate, a first current collector, and a second current collector. The housing defines a cavity and an opening connecting to the cavity. Both the first and second current collectors are housed within the cavity, and the cover plate covers the opening and connects to the housing. In related technologies, a laminated cell structure is used to reduce impedance and increase the charging rate. This laminated cell structure includes a laminated core and a steel housing. The laminated core is housed within the steel housing and bonded to the cover plate of the steel housing with hot melt adhesive. The steel-cased cell is relatively heavy, and during mechanical reliability testing (such as directional drop testing), repeated impacts and pulls can tear the electrodes bonded with hot melt adhesive, and the tears can easily puncture the separator, leading to a short circuit. In this solution, the second current collector is located between the cover plate and the first current collector, and is bonded to the cover plate and stacked. The second current collector has the same polarity as the first current collector. The tensile strength of the second current collector is greater than that of the first current collector. Compared to existing cells, this is equivalent to enhancing the tensile strength of the second current collector. Therefore, it effectively prevents tearing of the second current collector, avoiding short circuits caused by cracks piercing the separator. This, in turn, ensures the reliability of the hot melt adhesive binding of the stacked cores, suppresses core movement within the steel shell, and prevents short circuits caused by weld damage or bending of the stacked core electrodes. In short, this solution effectively improves the impact resistance of the cell, enhances the safety of cell use, and ensures the energy density and charging rate of the cell. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the battery cell structure in one embodiment of the present invention.

[0029] Explanation of icon numbers:

[0030] Cell structure 10;

[0031] Shell 100; cavity 110; opening 120;

[0032] Cover plate 200;

[0033] First collector fluid 300;

[0034] Second fluid 400;

[0035] Third fluid unit 500;

[0036] Fourth collector fluid 600;

[0037] First diaphragm 700;

[0038] Second diaphragm 800;

[0039] Hot melt adhesive 910; wrapping adhesive 920.

[0040] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0041] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0042] The first aspect of this utility model provides a battery cell structure 10 that can effectively improve the impact resistance of the battery cell. It is understood that the battery cell structure 10 can be used for stacked battery cells. The following refers to... Figure 1 The following describes the battery cell structure 10 according to an embodiment of this application. Specifically, the battery cell structure 10 includes a housing 100, a cover plate 200, a first current collector 300, and a second current collector 400.

[0043] Reference Figure 1 The housing 100 is used to enclose the battery cell. It should be noted that the housing 100 can be a steel shell. The housing 100 defines a cavity 110 for housing the battery cell. The housing 100 has an opening 120 communicating with the cavity 110, allowing the battery cell to be removed and retrieved through the opening 120. It is understood that the housing 100 can be a square shell or a cylindrical shell, depending on the specific requirements. A cover plate 200 is used to connect to the housing 100 and cover the opening 120. Specifically, the cover plate 200 can be welded to the housing 100.

[0044] Reference Figure 1The specific configuration of the current collectors is described below. The first current collector 300 and the second current collector 400 can be housed in the cavity 110. The first current collector 300 and the second current collector 400 have the same polarity. Specifically, in some embodiments, both the first current collector 300 and the second current collector 400 can be negative current collectors. In other embodiments, both the first current collector 300 and the second current collector 400 can be positive current collectors. This embodiment uses the example of both the first current collector 300 and the second current collector 400 being negative current collectors for illustration. The second current collector 400 is located between the cover plate 200 and the first current collector 300, and the second current collector 400 is bonded to the cover plate 200 and stacked with it. Specifically, hot melt adhesive 910 can be used to connect the cover plate 200 and the second current collector 400. The tensile strength of the second current collector 400 is greater than the tensile strength of the first current collector 300.

[0045] In the technical solution of this utility model, the cell structure 10 includes a housing 100, a cover plate 200, a first current collector 300, and a second current collector 400. The housing 100 defines a cavity 110 and an opening 120 communicating with the cavity 110. The first current collector 300 and the second current collector 400 are both housed in the cavity 110, and the cover plate 200 can cover the opening 120 and connect to the housing 100. In related technologies, a laminated cell structure is used to reduce impedance and improve charging rate. The laminated cell structure includes a laminated core and a steel shell. The laminated core is housed in the steel shell and is bonded to the cover plate of the steel shell by hot melt adhesive. The steel shell cell is relatively heavy. During mechanical reliability testing (such as directional drop testing), repeated impacts and pulls can cause the electrode sheets bonded with hot melt adhesive to tear, and the tears can easily puncture the diaphragm, leading to a short circuit. The second current collector 400 in this design is located between the cover plate 200 and the first current collector 300, and is bonded to and stacked with the cover plate 200. The second current collector 400 and the first current collector 300 have the same polarity. The tensile strength of the second current collector 400 is greater than that of the first current collector 300, which is equivalent to enhancing the tensile strength of the second current collector 400 compared to existing battery cells. Therefore, it can effectively prevent the second current collector 400 from tearing, avoiding the situation where the tear punctures the diaphragm and causes a short circuit. This, in turn, ensures the reliability of the hot melt adhesive 910 binding the stacked cores, suppresses the movement of the stacked cores within the steel shell, and prevents short circuits caused by damage to the weld seams or bending of the stacked core electrodes. In other words, this design can effectively improve the impact resistance of the battery cell, enhance the safety of battery cell use, and ensure the energy density and charging rate of the battery cell.

[0046] Reference Figure 1In some embodiments, the cell structure 10 includes a third current collector 500, which is housed in a cavity 110. The polarity of the third current collector 500 is the same as that of the first current collector 300. This embodiment illustrates this by assuming both the third current collector 500 and the first current collector 300 are negative current collectors. The third current collector 500 is located between the first current collector 300 and the second current collector 400. The tensile strength of the second current collector 400 is greater than that of the third current collector 500. It is understood that in some embodiments, the tensile strength of the third current collector 500 may be equal to that of the first current collector 300. In other embodiments, the tensile strength of the third current collector 500 may be greater than or less than that of the first current collector 300. This embodiment illustrates this by assuming the tensile strength of the third current collector 500 is equal to that of the first current collector 300. This solution can improve the impact resistance of the cell and enhance the safety of cell use while having minimal impact on the cell's processing strength.

[0047] The specific configurations of the first current collector 300 and the second current collector 400 are described below. In some embodiments, the tensile strength of the first current collector 300 is K1. K1 satisfies the condition: K1 ≥ 300 MPa. For example, K1 can be 300 MPa, 320 MPa, 350 MPa, 380 MPa, 400 MPa, 440 MPa, 470 MPa, 520 MPa, 550 MPa, or 600 MPa, etc. In some embodiments, the tensile strength of the second current collector 400 is K2. K2 satisfies the condition: K2 ≥ 400 MPa. For example, K2 can be 400 MPa, 430 MPa, 450 MPa, 480 MPa, 500 MPa, 540 MPa, 580 MPa, 600 MPa, 700 MPa, or 800 MPa, etc. The first current collector 300 and the second current collector 400 of this solution adopt the above-mentioned configuration, which can improve the anti-collision performance of the battery cell and enhance the safety of battery cell use while having little impact on the processing strength of the battery cell.

[0048] The relative arrangement of the first current collector 300 and the second current collector 400 is described below. In some embodiments, the grain size of the second current collector 400 is the same as that of the first current collector 300. The thickness of the second current collector 400 is greater than that of the first current collector 300, so that the tensile strength of the second current collector 400 is greater than that of the first current collector 300. That is, this solution improves the impact resistance of the cell structure 10 by changing the thickness of the second current collector 400 and the first current collector 300 to adjust the tensile strength, ensuring the safety of the cell use, and the overall operation is convenient and quick.

[0049] The relative thickness ratio between the first current collector 300 and the second current collector 400 is described below. In some embodiments, the thickness of the first current collector 300 is H1, and the thickness of the second current collector 400 is H2. H1 and H2 satisfy the condition: 1 < H2 / H1 ≤ 7. For example, H2 / H1 can be 1.2, 1.5, 1.8, 2, 2.4, 2.7, 3, 3.5, 4.4, 4.6, 5, 5.5, 6, or 7, etc. By adopting the above-mentioned thickness ratio between the first current collector 300 and the second current collector 400 in this solution, the processing intensity of the battery cell can be reduced, while the impact resistance of the battery cell can be improved.

[0050] The specific thickness setting of the first current collector 300 is described below. In some embodiments, the thickness of the first current collector 300 is H1. Wherein, H1 satisfies: 4μm≤H1≤12μm. For example, H1 can be 4μm, 4.5μm, 4.8μm, 5.4μm, 5.7μm, 6μm, 6.4μm, 7μm, 8.8μm, 10μm, 11.8μm, or 12μm, etc.

[0051] The specific thickness setting of the second current collector 400 is described below. In some embodiments, the thickness of the second current collector 400 is H2. Wherein, H2 satisfies: 4μm ≤ H2 ≤ 25μm. Exemplarily, H2 can be 4μm, 4.5μm, 6μm, 7.4μm, 9μm, 11.5μm, 13.7μm, 16μm, 18.8μm, 22μm, 23.9μm, or 25μm, etc.

[0052] The relative arrangement of the first current collector 300 and the second current collector 400 is described below. In some embodiments, the second current collector 400 and the first current collector 300 have the same thickness. The grain size of the second current collector 400 is smaller than that of the first current collector 300, so that the tensile strength of the second current collector 400 is greater than that of the first current collector 300. This solution, by changing the grain size of the second current collector 400 and the first current collector 300 to adjust the tensile strength, can improve the impact resistance of the cell structure 10, ensure the safety of the cell use, and is convenient and quick to operate.

[0053] Reference Figure 1In some embodiments, the cell structure 10 includes a fourth current collector 600, a first separator 700, and a second separator 800 located within the cavity 110. The fourth current collector 600 is located between the first current collector 300 and the second current collector 400. The polarity of the fourth current collector 600 is different from that of the first current collector 300. Specifically, in some embodiments, the first current collector 300 can be a negative current collector, and the fourth current collector 600 can be a positive current collector. In other embodiments, the first current collector 300 can be a positive current collector, and the fourth current collector 600 can be a negative current collector. This application embodiment uses the example of the first current collector 300 being a negative current collector and the fourth current collector 600 being a positive current collector for illustration. The first separator 700 can be located between the first current collector 300 and the fourth current collector 600, and the second separator 800 can be located between the second current collector 400 and the fourth current collector 600. The current collector and separator arrangement of the cell structure 10 can be determined according to actual conditions.

[0054] It should be noted that, for reference only Figure 1 In some embodiments, the cell structure 10 includes an adhesive wrapping 920, which can be used to connect the second current collector 400 to the housing 100, or to connect the first current collector 300 to the housing 100. This solution can effectively suppress the movement of the cell relative to the housing 100, avoid short circuits caused by damage to the weld seam or bending of the stacked electrode sheets, and improve the impact resistance of the cell.

[0055] A second aspect of this utility model provides a battery comprising a cell structure 10 as described in the above embodiment. The tensile strength of the second current collector 400 in this solution is greater than that of the first current collector 300, which is equivalent to enhancing the tensile strength of the second current collector 400 compared to existing cells. Therefore, it effectively prevents tearing of the second current collector 400, avoiding short circuits caused by tears piercing the separator. This, in turn, ensures the reliability of the hot melt adhesive 910 binding the stacked cells, suppresses movement of the stacked cells within the steel shell, and prevents short circuits caused by weld breaks or bending of the stacked cell electrodes. In other words, this solution effectively improves the impact resistance of the cell, enhances the safety of cell use, and ensures the energy density and charging rate of the cell.

[0056] A third aspect of this utility model provides an electrical device, which includes a battery as described in the above embodiments. The battery is used to power the electrical device. It is understood that the electrical device can be a mobile phone, tablet computer, laptop computer, battery-powered toy, power tool, or electric vehicle, etc., and the specific application depends on the actual situation. The battery in this solution can ensure the safety and reliability of the electrical device's operation.

[0057] The following describes the test setup for a specific embodiment of the battery cell structure 10 of this application. First, a steel-cased laminated battery cell is prepared, comprising a casing 100, a cover plate 200, a first current collector 300, a second current collector 400, and a third current collector 500. The first current collector 300 and the third current collector 500 are both made of 6μm ordinary tensile strength copper foil, while the second current collector 400 is made of copper foil with ordinary tensile strength of 6µm, high tensile strength of 6µm, ultra-high tensile strength of 6µm, ordinary tensile strength of 12µm, and ordinary tensile strength of 20µm, respectively. Table 1 shows the specific test parameters and test results.

[0058]

[0059] Table 1

[0060] As shown in Tables 1-3 and Comparative Example 1, under the same thickness, selecting a second current collector 400 with high tensile strength helps to alleviate the tearing of the cell structure 10 during mechanical reliability testing. Specifically, the tensile strength of the current collector can be improved by selecting a current collector with small-sized grains.

[0061] As can be seen from Table 1 Examples 4-5 and Comparative Example 1, when the characteristic parameters of the second current collector 400 are the same, selecting a thicker second current collector 400 can improve the tensile strength and help alleviate the tearing of the cell structure 10 in the mechanical reliability test.

[0062] The following describes the testing method for cell structure 10. After the cell is manufactured, it is charged to full charge at 0.7C for 30 cycles. Then, double-sided tape is applied to the finished cell, and it is placed in a fixture to simulate a drop test on the whole machine. The cell is dropped from a height of 1m onto a marble floor, with each of the 6 sides and 4 corners being dropped as one round. After 5 rounds of drops, the cell is disassembled to check the tearing condition of the second current collector 400.

[0063] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0064] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or," "and / or," or "and / or" throughout the text implies three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where A and B are simultaneously satisfied. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0065] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the inventive concept of this utility model and the contents of this utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A cell structure, characterized in that, include: A housing that defines a cavity and an opening communicating with the cavity; A cover plate, adapted to cover the opening and connect to the housing; The first fluid collector is contained within the cavity; The second current collector is housed in the cavity and located between the cover plate and the first current collector. The second current collector is bonded to the cover plate and arranged in a stacked manner. The second current collector has the same polarity as the first current collector, and the tensile strength of the second current collector is greater than that of the first current collector.

2. The cell structure as described in claim 1, characterized in that, The cell structure includes a third current collector, which is housed in the cavity and located between the first current collector and the second current collector; The polarity of the third current collector is the same as that of the first current collector, and the tensile strength of the second current collector is greater than that of the third current collector.

3. The cell structure as described in claim 1, characterized in that, The tensile strength of the first current collector is K1, wherein K1 satisfies: K1≥300MPa; And / or, The tensile strength of the second current collector is K2, where K2 satisfies: K2≥400MPa.

4. The cell structure as described in claim 1, characterized in that, The second current collector has the same grain size as the first current collector, and the thickness of the second current collector is greater than that of the first current collector, so that the tensile strength of the second current collector is greater than that of the first current collector.

5. The cell structure as described in claim 4, characterized in that, The thickness of the first current collector is H1, and the thickness of the second current collector is H2, wherein H1 and H2 satisfy the condition: 1 < H2 / H1 ≤ 7.

6. The cell structure as described in claim 4, characterized in that, The thickness of the first current collector is H1, wherein H1 satisfies: 4μm≤H1≤12μm; And / or, The thickness of the second current collector is H2, wherein H2 satisfies: 4μm≤H2≤25μm.

7. The cell structure as described in claim 1, characterized in that, The second current collector has the same thickness as the first current collector, and the grain size of the second current collector is smaller than that of the first current collector, so that the tensile strength of the second current collector is greater than that of the first current collector.

8. The cell structure as described in claim 1, characterized in that, The cell structure includes a fourth current collector, a first diaphragm, and a second diaphragm located within the cavity, wherein the fourth current collector is located between the first current collector and the second current collector; The polarity of the fourth current collector is different from that of the first current collector, the first diaphragm is located between the fourth current collector and the first current collector, and the second diaphragm is located between the fourth current collector and the second current collector.

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

10. Electrical equipment, characterized in that, Includes the battery as described in claim 9.

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