Battery cell and battery pack

Abstract

The utility model provides an electric core and a battery pack, the electric core comprises a positive pole shell, a positive pole pressed powder, a first current collector and a second current collector, one side of the first current collector deviating from the positive pole shell is provided with a groove, the second current collector is arranged on one side of the positive pole pressed powder facing the positive pole shell, and at least part of the second current collector is positioned in a through hole of the groove and is electrically connected with the positive pole shell; the second current collector is arranged in the groove of the first current collector to form a double-current-collector structure, so that the pulse performance of the battery cell is improved.

Description

Technical Field

[0001] This utility model relates to the field of power battery technology, specifically to a battery cell and a battery pack. Background Technology

[0002] In related technologies, the single current collector design of the positive electrode leads to poor contact with the positive electrode shell, resulting in insufficient pulse discharge capability. At the end of the discharge, telecommunication expansion or other factors cause poor contact between the positive electrode and the positive electrode shell, further weakening the pulse capability.

[0003] Therefore, the battery cells in the relevant technologies have the technical problem of insufficient pulse discharge capability. Utility Model Content

[0004] The embodiments of this utility model provide a battery cell and a battery pack, which can improve the technical problem of insufficient pulse discharge capability of the battery cell in the prior art.

[0005] In a first aspect, embodiments of the present invention provide a battery cell, comprising:

[0006] The housing includes a positive electrode shell and a negative electrode shell connected to each other, and the positive electrode shell and the negative electrode shell enclose a cavity;

[0007] A positive electrode powder cake, wherein the positive electrode powder cake is disposed within the cavity;

[0008] A first current collector is disposed within the cavity and in contact with the positive electrode shell. A groove is provided on the side of the first current collector facing away from the positive electrode shell. At least a portion of the positive electrode powder cake is located within the groove, and a through hole is formed on the bottom surface of the groove.

[0009] The second current collector is disposed on the side of the positive electrode powder cake facing the positive electrode shell, and the second current collector is at least partially located in the through hole and electrically connected to the positive electrode shell.

[0010] In one embodiment, the positive electrode powder cake has a protrusion on the side facing the positive electrode shell, the protrusion is inserted into the through hole, and the second current collector is disposed on the side of the protrusion facing the positive electrode shell.

[0011] In one embodiment, both the second current collector and the protrusion are circular structures, and the ratio of the diameter of the second current collector to the diameter of the protrusion ranges from 0.5 to 0.9.

[0012] In one embodiment, the surface of the second current collector away from the positive electrode powder cake is flush with the same surface of the first current collector away from the positive electrode powder cake.

[0013] In one embodiment, the second current collector is a ducted wire mesh structure, wherein the ratio of the long pitch to the short pitch of the ducted wire mesh structure ranges from 1 to 3.

[0014] In one embodiment, the positive electrode powder cake and the second current collector are integrally formed.

[0015] In one embodiment, the first current collector and the second current collector are connected by welding.

[0016] In one embodiment, the positive electrode powder cake has a planar surface on one side where the second current collector is provided, and the second current collector at least covers the through hole.

[0017] In one embodiment, the through hole is filled with conductive adhesive, which connects the second current collector and the positive electrode shell.

[0018] Secondly, embodiments of the present invention provide a battery pack comprising the battery cells as described in any of the above embodiments.

[0019] The beneficial effects of the embodiments of this utility model are as follows:

[0020] In an embodiment of this utility model, a second current collector is added to the groove of the first current collector. The second current collector is electrically connected to the positive electrode shell through a through hole located on the first current collector. During pulse discharge, efficient contact between the dual current collector structure and the positive electrode shell is achieved, improving the pulse performance of the battery cell and alleviating the technical problem of insufficient pulse discharge capability of the battery cell in the prior art. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments 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 these drawings without creative effort.

[0022] Figure 1 This is a diagram illustrating the first manufacturing process of a battery cell provided in an embodiment of this utility model;

[0023] Figure 2 This is a diagram illustrating the second manufacturing process of the battery cell provided in an embodiment of this utility model;

[0024] Figure 3 This is a top view schematic diagram of the second current collector in the battery cell provided by an embodiment of this utility model;

[0025] Figure 4 This is a top view schematic diagram of the first current collector in the battery cell provided in an embodiment of this utility model. Detailed Implementation

[0026] 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 skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0027] Furthermore, the terms "first," "second," and similar words do not indicate any order, quantity, or importance, but are merely used to distinguish different technical features. The terms "multiple" and similar words indicate two or more unless otherwise expressly specified.

[0028] Please see Figure 1 and Figure 2 The battery cell provided in the embodiment of this utility model includes a housing 2, a positive electrode powder cake 1, a first current collector 3, and a second current collector 4. The housing 2 includes a positive electrode shell 21 and a negative electrode shell 22 connected to each other. The positive electrode shell 21 and the negative electrode shell 22 enclose a cavity. The positive electrode powder cake 1 is disposed in the cavity. The first current collector 3 is disposed in the cavity and is in contact with the positive electrode shell 21. The first current collector 3 has a groove on the side away from the positive electrode shell 21. The positive electrode powder cake 1 is at least partially located in the groove. A through hole is opened on the bottom surface of the groove. The second current collector 4 is disposed on the side of the positive electrode powder cake 1 facing the positive electrode shell 21. The second current collector 4 is at least partially located in the through hole and is electrically connected to the positive electrode shell 21.

[0029] In this embodiment, a second current collector 4 is added to the groove of the first current collector 3. The second current collector 4 is electrically connected to the positive electrode shell 21 through a through hole located on the first current collector 3. During pulse discharge, the dual current collector structure and the positive electrode shell 21 are made into efficient contact, which improves the pulse performance of the cell and alleviates the technical problem of insufficient pulse discharge capability of the cell in the prior art.

[0030] The technical solution of this application will now be described in conjunction with specific embodiments.

[0031] In one embodiment, please refer to Figure 1The positive electrode powder cake 1 has a protrusion on the side facing the positive electrode shell 21, the protrusion is inserted into the through hole, and the second current collector 4 is disposed on the side of the protrusion facing the positive electrode shell 21.

[0032] It is understandable that the positive electrode powder cake 1 has protrusions, which increases the capacity of the positive electrode powder cake 1 and thus enhances the capacity of the battery cell. At the same time, the protrusions make the contact between the second current collector 4 and the positive electrode shell 21 better, and also improve the contact effect between the second current collector 4 and the positive electrode shell 21.

[0033] In one embodiment, please refer to Figure 1 Both the second current collector 4 and the protrusion are circular structures, and the ratio of the diameter of the second current collector 4 to the diameter of the protrusion ranges from 0.5 to 0.9.

[0034] The ratio of the diameter of the second current collector 4 to the diameter of the protrusion can be any one of 0.5, 0.6, 0.7, 0.8, or 0.9.

[0035] It is understandable that if the diameter ratio of the second current collector 4 to the protrusion is greater than 0.9, the second current collector 4 is prone to exceeding the protrusion due to process errors, resulting in material waste; if the diameter ratio of the second current collector 4 to the protrusion is less than 0.5, the area of ​​the second current collector 4 is too small, and the improvement on the battery pulse capability of the cell is not significant.

[0036] In one embodiment, the surface of the second current collector 4 away from the positive electrode powder cake 1 is flush with the same surface of the first current collector 3 away from the positive electrode powder cake 1.

[0037] It is understandable that during the formation of the positive electrode, the surface of the second current collector 4 that is away from the positive electrode powder cake 1 and is in contact with the positive electrode shell 21 is not lower than the same surface of the first current collector 3 that is away from the positive electrode powder cake 1; after the cell is formed, the surface of the second current collector 4 in the cell that is in contact with the positive electrode shell 21 is compressed, causing it to be flush with the same surface of the first current collector 3 that is away from the positive electrode powder cake 1.

[0038] It should be noted that since the second current collector 4 can directly contact the positive electrode shell 21, the conductive adhesive 5 on the surface of the positive electrode shell 21 used for contacting the second current collector 4 can be removed, thereby reducing costs.

[0039] In one embodiment, please refer to Figure 3 The second current collector 4 is a inclined wire mesh structure, and the ratio of the long pitch b to the short pitch a of the inclined wire mesh structure ranges from 1 to 3.

[0040] The second current collector 4 is provided with a mesh. The mesh of the inclined wire mesh structure can be rhomboid. The mesh can make it easier for the current collector to be combined with the positive electrode powder cake 1, thereby reducing the processing difficulty.

[0041] The ratio of the long pitch b to the short pitch a in the inclined wire mesh structure can be, but is not limited to, 1, 2, or 3.

[0042] It is understood that the ratio of the long pitch b to the short pitch a of the inclined wire mesh structure ranges from 1 to 3 to accommodate different cell models.

[0043] In one embodiment, the positive electrode powder cake 1 and the second current collector 4 are integrally formed.

[0044] It is understandable that the positive electrode powder cake 1 and the second current collector 4 are integrally formed, thereby simplifying the process and reducing costs.

[0045] In one embodiment, the first current collector 3 and the second current collector 4 are connected by welding.

[0046] It is understandable that by first welding the first current collector 3 to the second current collector 4, and then assembling them with the positive electrode powder cake 1, poor contact caused by assembling the first current collector 3 and the second current collector 4 with the positive electrode powder cake 1 respectively can be avoided.

[0047] In one embodiment, the positive electrode powder cake 1 has a planar surface on one side where the second current collector 4 is located, and the second current collector 4 at least covers the through hole.

[0048] Please refer to Figure 4 Both the second current collector 4 and the positive electrode powder cake 1 can be circular in shape, and the ratio of the diameter of the second current collector 4 to the diameter of the positive electrode powder cake 1 is in the range of 0.5 to 0.9.

[0049] It is understood that the second current collector 4 at least covers the through hole, thereby increasing the contact area between the second current collector 4 and the positive electrode shell 21 through the through hole.

[0050] In one embodiment, the through hole is filled with conductive adhesive 5, which connects the second current collector 4 and the positive electrode shell 21.

[0051] It is understandable that filling the through hole with conductive adhesive 5 helps to enhance the electrical connection between the second current collector 4 and the conductive housing 2.

[0052] In one embodiment, the second current collector 4 has a mesh structure.

[0053] The mesh structure can be a diagonal mesh structure or a woven mesh structure, and the second current collector 4 can be, but is not limited to, at least one of stainless steel, aluminum, and nickel.

[0054] It is understandable that the second current collector 4 is made of at least one of stainless steel, aluminum, and nickel, which makes the battery cell with the second current collector 4 perform better in terms of high current pulses.

[0055] In one embodiment, the contact surfaces of the first current collector 3 and the second current collector 4 with the positive electrode powder cake 1 are frosted or have burrs, thereby increasing the bonding force between the first current collector 3 and the second current collector 4 and the positive electrode powder cake 1 and preventing the first current collector 3 and the second current collector 4 from falling off the positive electrode powder cake 1.

[0056] In one embodiment, the ratio of the thickness of the protrusion to the thickness of the second current collector 4 ranges from 0.5:1 to 0.9:1.

[0057] The ratio of the thickness of the protrusion to the thickness of the second current collector 4 can be 0.5:1, 0.7:1, or 0.9:1.

[0058] In one embodiment, the second current collector 4 can be embedded in the positive electrode powder cake 1.

[0059] It is understandable that embedding the second current collector 4 into the positive electrode powder cake 1 can reduce the space occupied by the second current collector 4 in the cavity, thereby appropriately increasing the volume of the positive electrode powder cake 1, thereby increasing the cell capacity and extending the battery life.

[0060] In one embodiment, the positive electrode powder cake 1 is mostly made of manganese powder. To better combine the first current collector 3 and the second current collector 4, the compaction density of the positive electrode powder cake 1 is in the range of 2.0 g / mm². 3 Up to 3.0 g / mm 3 .

[0061] The compaction density of the positive electrode powder 1 can be, but is not limited to, 2.0 g / mm². 3 2.5g / mm 3 3.0g / mm 3 Any one of them.

[0062] In one embodiment, the second current collector 4 and the positive electrode powder cake 1 can be placed concentrically.

[0063] Secondly, embodiments of the present invention provide a battery pack comprising the battery cells as described in any of the above embodiments.

[0064] Thirdly, embodiments of this utility model provide a method for preparing a battery cell, used to prepare a battery cell as described in any of the above embodiments.

[0065] In one embodiment, please refer to Figure 1 and Figure 2 The methods for manufacturing battery cells include:

[0066] S1: Material preparation;

[0067] S2: Assembly.

[0068] The material preparation process is used to prepare the positive electrode, negative electrode 7, and separator 6; the assembly process is used to combine the positive electrode, negative electrode 7, and separator 6 into a battery cell.

[0069] Please see Figure 1 and Figure 2 Example 1: Material preparation includes positive electrode preparation, negative electrode preparation, and separator preparation.

[0070] Among them, the positive electrode preparation: the positive electrode powder and the second current collector 4 are pressed together to form a 2.8g / mm² material. 3 Up to 3.1 g / mm 3 The positive electrode component is formed by connecting the positive electrode ring to the aforementioned positive electrode component ring.

[0071] Among them, the preparation of negative electrode 7: the negative electrode 7 is pressed into a disc using a mold of the corresponding shape.

[0072] Among them, the preparation of the diaphragm 6: the non-woven fabric diaphragm 6 is cut using a corresponding mold and completely covers the negative electrode 7.

[0073] The assembly process includes: adding electrolyte, placing the positive electrode, and sealing.

[0074] Among them, electrolyte is added dropwise: electrolyte is added dropwise above the diaphragm 6.

[0075] Among them, placing the positive electrode: placing the positive electrode after the collar is placed above the diaphragm 6.

[0076] Among them, sealing: combining the positive electrode shell 21 and the negative electrode shell 22 to encapsulate a sealed battery cell.

[0077] Example 2: Unlike Example 1 above, conductive adhesive 5 can also be applied to the side of the positive electrode shell 21 facing the positive electrode, so that the positive electrode can be better electrically connected to the positive electrode shell 21 through the conductive adhesive 5.

[0078] Example 3: Unlike Examples 1 and 2 above, the first current collector 3 and the second current collector 4 can be welded together to form a whole, and then the whole can be assembled with the powder cake to form a positive electrode.

[0079] Understandably, this increases the flexibility in preparing the cathode, allowing the technology to adapt to different production needs.

[0080] In some embodiments, the material of the second fluid 4 can also be optimized.

[0081] The second current collector 4 can be made of materials such as stainless steel, aluminum, and nickel.

[0082] The second current collector 4 can also be a lighter material with better conductivity to further improve the energy density and pulse performance of the battery.

[0083] Understandably, lighter and more conductive materials refer to materials that are lighter and have better conductivity compared to materials such as stainless steel, aluminum, and nickel.

[0084] In some embodiments, the environmental adaptability of the battery cell can also be improved by studying the performance of the battery cell with the first current collector 3 and the second current collector 4 in different environments, such as the performance under extreme conditions such as high temperature, low temperature, and high humidity, so as to ensure the stability of the battery cell in various application scenarios.

[0085] This invention improves the performance of the battery cell during pulse discharge by combining the first current collector 3 and the second current collector 4. At the same time, the second current collector 4 also enhances the contact effect with the positive electrode shell 21. When the first current collector 3 has a ring structure, the second current collector 4 fills the hollow part of the ring structure, increases the contact area between the positive electrode and the positive electrode shell 21, and reduces the problem of poor contact.

[0086] This invention is applicable to scenarios requiring high-pulse discharge, such as power tools, drones, and medical equipment. Furthermore, under high temperature or cell expansion conditions, traditional single-ring designs are prone to poor contact problems, while the dual current collector structure with a first current collector 3 and a second current collector 4 can effectively address these challenges and ensure the stable performance of the cell.

[0087] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A battery cell, characterized in that, include: The housing (2) includes a positive electrode shell (21) and a negative electrode shell (22) connected to each other, and the positive electrode shell (21) and the negative electrode shell (22) enclose a cavity; Positive electrode powder cake (1), wherein the positive electrode powder cake (1) is disposed in the cavity; A first current collector (3) is disposed within the cavity and in contact with the positive electrode shell (21). A groove is provided on the side of the first current collector (3) facing away from the positive electrode shell (21). The positive electrode powder cake (1) is at least partially located within the groove. A through hole is provided on the bottom surface of the groove. The second current collector (4) is disposed on the side of the positive electrode powder cake (1) facing the positive electrode shell (21), and the second current collector (4) is at least partially located in the through hole and electrically connected to the positive electrode shell (21).

2. The battery cell according to claim 1, characterized in that, The positive electrode powder cake (1) has a protrusion on the side facing the positive electrode shell (21), the protrusion is inserted into the through hole, and the second current collector (4) is disposed on the side of the protrusion facing the positive electrode shell (21).

3. The battery cell according to claim 2, characterized in that, Both the second current collector (4) and the protrusion are circular structures, and the ratio of the diameter of the second current collector (4) to the diameter of the protrusion is in the range of 0.5 to 0.

9.

4. The battery cell according to claim 2, characterized in that, The surface of the second current collector (4) away from the positive electrode powder cake (1) is flush with the same surface of the first current collector (3) away from the positive electrode powder cake (1).

5. The battery cell according to claim 1, characterized in that, The second current collector (4) is a inclined wire mesh structure, and the ratio of the long pitch to the short pitch of the inclined wire mesh structure is in the range of 1 to 3.

6. The battery cell according to claim 1, characterized in that, The positive electrode powder cake (1) and the second current collector (4) are integrally formed.

7. The battery cell according to claim 1, characterized in that, The first current collector (3) and the second current collector (4) are connected by welding.

8. The battery cell according to claim 1, characterized in that, The positive electrode powder cake (1) has a planar surface on one side of the second current collector (4), and the second current collector (4) at least covers the through hole.

9. The battery cell according to claim 1, characterized in that, The through hole is filled with conductive adhesive (5), which is connected between the second current collector (4) and the positive electrode shell (21).

10. A battery pack, characterized in that, Includes the battery cell as described in any one of claims 1 to 9.

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