Battery structure

Abstract

The utility model provides a battery structure. The battery structure comprises: a housing; the double-roll-core structure comprises a first roll core and a second roll core, the first roll core and the second roll core are arranged in an inner cavity of the shell side by side in a spaced mode in the first direction, a first tab group and a second tab group are connected between the first roll core and the second roll core, and the first tab group and the second tab group are arranged in a spaced mode in the second direction, the first direction is perpendicular to the second direction. According to the battery structure adopting the technical scheme, the problems that the occupation of the internal space of the battery is increased and the strip is easy to break in the manufacturing process due to the fact that a double-roll-core structure of an existing battery needs to be bent into a C shape or an S shape before entering a shell can be solved.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, and more specifically, to a battery structure. Background Technology

[0002] With the increasing global demand for green energy, especially the rapid development of my country's new energy vehicle industry, the performance and production efficiency of power batteries have become a focus of industry attention. Lithium-ion batteries, with their high voltage, high energy density, and low self-discharge rate, have shown enormous application potential in new energy vehicles, portable electronic devices, and energy storage systems. In the manufacturing of lithium-ion batteries, prismatic batteries are widely favored due to their compact structure and high energy density. The manufacturing process of the core of its internal structure—the rolled core—directly affects the overall performance and production cost of the battery. The manufacturing of prismatic lithium-ion battery cores typically employs two methods: winding and stacking. Among these, the winding process dominates in the large-scale production of power batteries due to its long history, mature technology, good cost control, high production yield, and fast production efficiency.

[0003] Currently, most wound lithium-ion batteries adopt a dual-core structure, meaning the battery contains two independent cores. This design is beneficial for improving battery energy density and overall performance. However, the manufacturing process of the dual-core structure also presents some challenges. In traditional processes, the two cores are wound independently, and then their respective positive and negative electrode tabs need to be connected to the tab connecting piece by welding. The tab connecting piece is then further welded to the cover plate terminals. During this process, the tabs need to be bent into a C-shape or S-shape before being inserted into the battery casing to adapt to the battery casing structure. However, the higher tab height not only increases the internal space occupied by the battery and reduces energy density, but also easily causes strip breakage during manufacturing, increasing the scrap rate in the production process. Utility Model Content

[0004] The main objective of this invention is to provide a battery structure that solves the problem that the existing dual-core structure of batteries needs to be bent into a C-shape or S-shape before being inserted into the casing, which increases the internal space occupied by the battery and makes the strip material prone to breakage during the manufacturing process.

[0005] To achieve the above objectives, this utility model provides a battery structure, including: a housing; a dual-core structure, including a first core and a second core, the first core and the second core being arranged side by side at intervals in the inner cavity of the housing along a first direction, a first tab group and a second tab group being connected between the first core and the second core, the first tab group and the second tab group being arranged at intervals along a second direction, wherein the first direction is perpendicular to the second direction.

[0006] The above configuration can significantly reduce the height of the first and second tab groups, saving space inside the casing and thus increasing the energy density of the battery structure. It can also reduce the physical stress on the first and second tab groups, thereby reducing the frequency of breakage during manufacturing and improving production yield.

[0007] Furthermore, along the second direction, the dual-core structure has a first side and a second side arranged opposite to each other. The battery structure also includes a first cover plate and a first connecting piece. One end of the first connecting piece is connected to the first tab group. Both the first cover plate and the first tab group are arranged on the first side of the dual-core structure. The first cover plate is located on the side of the first tab group away from the second tab group and is connected to the other end of the first connecting piece.

[0008] The above setup enables the connection between the first tab assembly and the first cover plate, ensuring a stable electrical connection between the inside and outside of the battery.

[0009] Furthermore, the battery structure also includes a second cover plate and a second connecting piece. One end of the second connecting piece is connected to the second tab group. Both the second cover plate and the second tab group are disposed on the second side of the double-core structure. The second cover plate is located on the side of the second tab group away from the first tab group and is connected to the other end of the second connecting piece.

[0010] The above setup enables the connection between the second tab assembly and the second cover plate, ensuring a stable electrical connection between the inside and outside of the battery.

[0011] Furthermore, the first cover plate and the first connecting piece are an integral structure, while the second cover plate and the second connecting piece are separate structures; or, the first cover plate and the first connecting piece are separate structures, while the second cover plate and the second connecting piece are an integral structure.

[0012] By implementing the above settings, assembly steps in the production process can be reduced, and quality problems caused by uneven welding or defects can be avoided, thereby improving production efficiency and the yield of battery structures.

[0013] Furthermore, the shell is a cylindrical structure with openings at both ends. A first cover plate is placed on one of the two openings and connected to the shell, and a second cover plate is placed on the other of the two openings and connected to the shell.

[0014] The above design effectively prevents electrolyte leakage, improves the sealing and safety of the battery structure, and facilitates battery assembly and subsequent maintenance.

[0015] Furthermore, a plurality of first adhesive tapes are provided on the first core, and the plurality of first adhesive tapes are spaced apart along the circumference of the first core; a plurality of second adhesive tapes are provided on the second core, and the plurality of second adhesive tapes are spaced apart along the circumference of the second core.

[0016] The above setup effectively secures the first and second cores, reducing core deformation caused by internal stress or external vibration during charging and discharging, and ensuring the stability and consistency of the battery structure.

[0017] Furthermore, the first tape and / or the second tape are provided with multiple through holes.

[0018] With the above settings, on the one hand, the compression of the core caused by the first and second tapes during the hot pressing process can be reduced, thereby reducing the internal stress of the battery structure and improving the structural stability and consistency of the battery structure. On the other hand, during the charging and discharging process of the battery, heat will be generated inside, and the through holes facilitate the dissipation of heat, preventing local overheating, and thus improving the safety and reliability of the battery structure.

[0019] Furthermore, the dual-core structure also includes a positive electrode plate, which has a first active material region.

[0020] With the above settings, reversible insertion and deintercalation reactions with lithium ions can be carried out during charging and discharging, thereby achieving energy storage and release.

[0021] Furthermore, the dual-core structure also includes a negative electrode sheet, which has a second active material region. The first active material region and the second active material region are correspondingly arranged and can cover the first active material region.

[0022] Through the above settings, reversible insertion and deintercalation reactions with lithium ions occur during the charging and discharging process of the battery, thereby achieving energy storage and release.

[0023] Furthermore, the first electrode group includes multiple first electrodes stacked along its own thickness direction, and the second electrode group includes multiple second electrodes stacked along its own thickness direction. The first electrodes are positive electrodes, and the second electrodes are negative electrodes.

[0024] Through the above configuration, on the one hand, the cross-sectional area connected to the external circuit of the battery can be increased, the current density of a single tab can be reduced, and the internal resistance of the battery can be reduced, thereby improving the charging and discharging performance of the battery. On the other hand, it helps to disperse the heat generated during battery charging and discharging. Since the current is distributed on multiple tabs, local overheating can be avoided, the thermal management of the battery can be optimized, and the safety and reliability of the battery can be improved. Furthermore, the stacking of multiple tabs can enhance the structural stability of the dual-core structure, reduce the deformation or breakage of the tabs during manufacturing and use, thereby ensuring the stability and consistency of the battery structure.

[0025] Applying the technical solution of this utility model, the first and second cores of the dual-core structure of this application are arranged side by side, that is, the first and second cores are laid flat and located on the same horizontal plane. Compared with the dual-core structure of the prior art, the dual-core structure of this application does not require stacking the first and second cores. The first tab group and the second tab group are arranged between the first and second cores and spaced apart along the second direction. The first tab group and the second tab group do not need to be bent in a C-shape or S-shape, which can significantly reduce the height of the first tab group and the second tab group, save space in the casing, thereby improving the energy density of the battery structure. It can also reduce the physical stress on the first tab group and the second tab group, thereby reducing the frequency of tape breakage during the manufacturing process and improving the production yield. Attached Figure Description

[0026] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments and descriptions of this utility model are used to explain this utility model and do not constitute an undue limitation thereof. In the drawings:

[0027] Figure 1 A schematic diagram of the dual-core structure of an embodiment of the present invention is shown at one angle.

[0028] Figure 2 This diagram shows a structural schematic of the double-core structure of an embodiment of the present invention from another angle;

[0029] Figure 3 A schematic diagram of the structure of the positive electrode sheet with a double-wound core structure according to an embodiment of the present invention is shown;

[0030] Figure 4 This diagram shows the structure of the positive electrode sheet with a double-wound core structure according to an embodiment of the present invention before it is die-cut.

[0031] The above figures include the following reference numerals:

[0032] 10. Double core structure; 11. First core; 111. First tape; 12. Second core; 121. Second tape; 13. First tab assembly; 14. Second tab assembly; 20. First connecting piece; 30. Second connecting piece; 40. First cover plate; 50. Second cover plate; 60. Positive electrode plate; 61. First active material region; 62. Positive tab; 63. Optical foil region. Detailed Implementation

[0033] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. The present utility model will now be described in detail with reference to the accompanying drawings and embodiments.

[0034] See also Figure 1 and Figure 2 As shown, this utility model provides a battery structure, which includes: a housing; a dual-core structure 10, including a first core 11 and a second core 12, the first core 11 and the second core 12 are arranged side by side at intervals in the inner cavity of the housing along a first direction, a first tab group 13 and a second tab group 14 are connected between the first core 11 and the second core 12, the first tab group 13 and the second tab group 14 are arranged at intervals along a second direction, wherein the first direction is perpendicular to the second direction.

[0035] In this embodiment, the first direction refers to Figure 1 The width direction of the double-core structure 10, the second direction refers to Figure 1 The length direction of the dual-core structure 10. In this application, the first core 11 and the second core 12 of the dual-core structure 10 are arranged side by side, that is, the first core 11 and the second core 12 are laid flat and located on the same horizontal plane. Compared with the dual-core structure of the prior art, the dual-core structure 10 of this application does not require the first core 11 and the second core 12 to be stacked. The first tab group 13 and the second tab group 14 are arranged between the first core 11 and the second core 12 and are spaced apart along the second direction. The first tab group 13 and the second tab group 14 do not need to be bent in a C-shape or S-shape, which can significantly reduce the height of the first tab group 13 and the second tab group 14, save space in the casing, thereby improving the energy density of the battery structure. It can also reduce the physical stress on the first tab group 13 and the second tab group 14, thereby reducing the frequency of tape breakage during the manufacturing process and improving the production yield.

[0036] In addition, since the first tab group 13 and the second tab group 14 are located between the first core 11 and the second core 12, and the first tab group 13 and the second tab group 14 are located in the central area of ​​the battery structure, this helps the electrolyte to wet the entire cell more evenly and quickly. The electrolyte can diffuse from the center to the surrounding area, which can avoid the problem of uneven wetting, thereby improving the electrochemical performance and consistency of the dual core structure 10.

[0037] See also Figure 1 and Figure 2 As shown, in one embodiment of the present invention, along the second direction, the double-core structure 10 has a first side and a second side arranged opposite to each other. The battery structure also includes a first cover plate 40 and a first connecting piece 20. One end of the first connecting piece 20 is connected to the first tab group 13. The first cover plate 40 and the first tab group 13 are both arranged on the first side of the double-core structure 10. The first cover plate 40 is located on the side of the first tab group 13 away from the second tab group 14 and is connected to the other end of the first connecting piece 20.

[0038] In this embodiment, the first tab assembly 13 does not require bending and is directly welded to the first connecting piece 20. This reduces the physical stress on the first tab assembly 13, thereby reducing the frequency of breakage during manufacturing and improving production yield. Through this arrangement, the connection between the first tab assembly 13 and the first cover plate 40 can be achieved, ensuring a stable electrical connection between the inside and outside of the battery.

[0039] See also Figure 1 and Figure 2 As shown, in one embodiment of the present invention, the battery structure further includes a second cover plate 50 and a second connecting piece 30. One end of the second connecting piece 30 is connected to the second tab group 14. The second cover plate 50 and the second tab group 14 are both disposed on the second side of the double core structure 10. The second cover plate 50 is located on the side of the second tab group 14 away from the first tab group 13 and is connected to the other end of the second connecting piece 30.

[0040] In this embodiment, the second tab assembly 14 does not require bending and is directly welded to the second connecting piece 30. This reduces the physical stress on the second tab assembly 14, thereby reducing the frequency of breakage during manufacturing and improving production yield. Through this arrangement, the connection between the second tab assembly 14 and the second cover plate 50 can be achieved, ensuring a stable electrical connection between the inside and outside of the battery.

[0041] See also Figure 1 and Figure 2 As shown, in one embodiment of the present invention, the first cover plate 40 and the first connecting piece 20 are an integral structure, and the second cover plate 50 and the second connecting piece 30 are separate structures; or, the first cover plate 40 and the first connecting piece 20 are separate structures, and the second cover plate 50 and the second connecting piece 30 are an integral structure.

[0042] In this embodiment, the integrated structure (such as the first cover plate 40 and the first connecting piece 20) can reduce assembly steps in the production process and avoid secondary welding between the first cover plate 40 and the first connecting piece 20. This not only reduces manufacturing costs but also avoids quality problems caused by uneven welding or defects, thereby improving production efficiency and the yield of the battery structure. In addition, the integrated structure (such as the first cover plate 40 and the first connecting piece 20) can increase the integrity between the first cover plate 40 and the first connecting piece 20, which helps to improve the structural stability of the battery structure.

[0043] In one embodiment of the present invention, the housing is a cylindrical structure with openings at both ends. A first cover plate 40 is placed on one of the two openings and connected to the housing, and a second cover plate 50 is placed on the other of the two openings and connected to the housing.

[0044] In this embodiment, if the first cover plate 40 and the first connecting piece 20 are an integral structure, and the second cover plate 50 and the second connecting piece 30 are separate structures, before entering the shell, the first connecting piece 20 is welded to the first electrode lug 13, and then the double core structure 10 is placed inside the shell from one end opening. The first cover plate 40 is then assembled onto one opening of the shell and forms a sealed connection with the shell. Electrolyte is injected into the shell through the other opening. After the electrolyte is injected and left to stand for a period of time to fully wet the first core 11 and the second core 12, the second electrode lug 14 is welded to one end of the second connecting piece 30, and the other end of the second connecting piece 30 is welded to the second cover plate 50. Finally, the second cover plate 50 is assembled onto the other opening of the shell and forms a sealed connection with the shell.

[0045] In addition, the cylindrical structure design with openings at both ends, combined with the sealing connection of the first cover plate 40 and the second cover plate 50, can effectively prevent electrolyte leakage, improve the sealing and safety of the battery structure, and facilitate the assembly and subsequent maintenance of the battery structure.

[0046] See also Figure 1 and Figure 2 As shown, in one embodiment of the present invention, a plurality of first adhesive tapes 111 are provided on the first core 11, and the plurality of first adhesive tapes 111 are spaced apart along the circumference of the first core 11. A plurality of second adhesive tapes 121 are provided on the second core 12, and the plurality of second adhesive tapes 121 are spaced apart along the circumference of the second core 12.

[0047] In this embodiment, the first tape 111 and the second tape 121 can effectively fix the first core 11 and the second core 12, reduce the core deformation caused by internal stress or external vibration during charging and discharging, and ensure the stability and consistency of the battery structure.

[0048] In one embodiment of the present invention, a plurality of through holes are provided on the first tape 111 and / or the second tape 121.

[0049] With the above settings, on the one hand, the compression of the double-core structure 10 caused by the first tape 111 and the second tape 121 during the hot pressing process can be reduced, thereby reducing the internal stress of the battery structure and improving the structural stability and consistency of the battery structure. On the other hand, during the charging and discharging process of the battery, heat will be generated inside, and the through holes facilitate the dissipation of heat, prevent local overheating, and thus improve the safety and reliability of the battery structure.

[0050] See also Figures 1 to 3 As shown, in one embodiment of the present invention, the dual-core structure 10 further includes a positive electrode 60, which has a first active material region 61.

[0051] In this embodiment, the first active material region 61 is the region coated with a positive electrode active material, such as lithium cobalt oxide (LiCoO2), lithium nickel manganese cobalt oxide (NMC), lithium iron phosphate (LFP), etc. These active materials can undergo reversible insertion and deintercalation reactions with lithium ions during charging and discharging, thereby achieving energy storage and release.

[0052] In one embodiment of the present invention, the dual-core structure 10 further includes a negative electrode sheet, which has a second active material region. The first active material region 61 is correspondingly disposed with the second active material region and can cover the first active material region 61.

[0053] In this embodiment, the second active material region is the area coated with the negative electrode active material, such as graphite or silicon-based materials. During the battery's charging and discharging process, these materials undergo reversible insertion and extraction reactions with lithium ions, achieving energy storage and release. Simultaneously, the negative electrode active material region provides a migration path for lithium ions during charging and discharging. During charging, lithium ions are extracted from the positive electrode, pass through the electrolyte and separator, migrate to the negative electrode, and are inserted into the second active material region; during discharging, the process is reversed. The first active material region 61 is correspondingly positioned to the second active material region and can cover the first active material region 61. On one hand, this ensures unobstructed migration paths for lithium ions during charging and discharging, avoiding mismatches in lithium ion insertion and extraction between the positive and negative electrodes, and ensuring balanced electrochemical reactions. On the other hand, it effectively prevents premature degradation of the positive electrode material during battery cycling, as overcharging can lead to structural damage to the positive electrode material, while excess negative electrode material can buffer this process, thereby extending the battery's cycle life.

[0054] It should be noted that the dual-core structure 10 also includes a first separator and a second separator. The dual-core structure 10 is formed by winding the structure to be wound from one end to the other. The structure to be wound is formed by sequentially stacking the first separator, the positive electrode 60, the second separator, and the negative electrode. Wherein, as... Figure 4 As shown, the positive electrode 60 includes an aluminum foil, and there are two first active material regions 61. The two first active material regions 61 are spaced apart on the aluminum foil along the width direction of the positive electrode 60. There is a light foil region 63 between the two first active material regions 61. The light foil region 63 is die-cut to form multiple positive electrode tabs 62 (e.g., ...). Figure 3 (As shown).

[0055] The negative electrode sheet includes a copper foil and two second active material regions. These two second active material regions are spaced apart on the copper foil along the width of the negative electrode sheet. Between the two second active material regions are multiple uncoated foil regions. These foil regions of the negative electrode sheet are die-cut to form multiple negative electrode tabs. The spacing between the positive electrode tabs and the spacing between the negative electrode tabs satisfy the following: all the wound positive electrode tabs completely overlap to form a first electrode tab group, and all the wound negative electrode tabs completely overlap to form a second electrode tab group.

[0056] As can be seen from the above, the dual-core structure 10 of this application is completed by one winding. The positive and negative electrode tabs of the first core 11 and the second core 12 are the same whole. The separators (first separator and second separator) of the first core 11 and the second core 12 are separate structures and not connected in the middle. The size of the separator is larger than the size of the negative electrode sheet to ensure that the separator can cover the negative electrode sheet.

[0057] In one embodiment of the present invention, the first electrode group 13 includes a plurality of first electrodes stacked along its own thickness direction, and the second electrode group 14 includes a plurality of second electrodes stacked along its own thickness direction. The first electrodes are positive electrodes 62, and the second electrodes are negative electrodes.

[0058] Through the above settings, on the one hand, the cross-sectional area connected to the external circuit of the battery can be increased, the current density of a single tab can be reduced, and the internal resistance of the battery structure can be reduced, thereby improving the charging and discharging performance of the battery structure. On the other hand, it helps to disperse the heat generated during the charging and discharging of the battery structure. Since the current is distributed on multiple tabs, local overheating can be avoided, the thermal management of the battery structure can be optimized, and the safety and reliability of the battery structure can be improved. Furthermore, the stacking of multiple tabs can enhance the structural stability of the dual-core structure 10, reduce the deformation or breakage of the tabs during manufacturing and use, thereby ensuring the stability and consistency of the battery structure.

[0059] From the above description, it can be seen that the above embodiments of this utility model achieve the following technical effects: The first core and the second core of the dual-core structure of this application are arranged side by side, that is, the first core and the second core are laid flat and located on the same horizontal plane. Compared with the dual-core structure of the prior art, the dual-core structure of this application does not require stacking the first core and the second core. The first tab group and the second tab group are arranged between the first core and the second core and are spaced apart along the second direction. The first tab group and the second tab group do not need to be bent in a C-shape or S-shape. This can significantly reduce the height of the first tab group and the second tab group, save space in the casing, thereby improving the energy density of the battery structure. It can also reduce the physical stress on the first tab group and the second tab group, thereby reducing the frequency of tape breakage during the manufacturing process and improving the production yield.

[0060] Obviously, the embodiments described above are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0061] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0062] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A battery structure, characterized in that, include: case; The double-core structure (10) includes a first core (11) and a second core (12). The first core (11) and the second core (12) are arranged side by side and spaced apart in the inner cavity of the housing along a first direction. A first tab group (13) and a second tab group (14) are connected between the first core (11) and the second core (12). The first tab group (13) and the second tab group (14) are arranged spaced apart along a second direction, wherein the first direction is perpendicular to the second direction.

2. The battery structure according to claim 1, characterized in that, Along the second direction, the dual-core structure (10) has a first side and a second side arranged opposite to each other. The battery structure also includes a first cover plate (40) and a first connecting piece (20). One end of the first connecting piece (20) is connected to the first tab group (13). The first cover plate (40) and the first tab group (13) are both arranged on the first side of the dual-core structure (10). The first cover plate (40) is located on the side of the first tab group (13) away from the second tab group (14) and is connected to the other end of the first connecting piece (20).

3. The battery structure according to claim 2, characterized in that, The battery structure also includes a second cover plate (50) and a second connecting piece (30). One end of the second connecting piece (30) is connected to the second tab group (14). The second cover plate (50) and the second tab group (14) are both disposed on the second side of the double-core structure (10). The second cover plate (50) is located on the side of the second tab group (14) away from the first tab group (13) and is connected to the other end of the second connecting piece (30).

4. The battery structure according to claim 3, characterized in that, The first cover plate (40) and the first connecting piece (20) are an integral structure, and the second cover plate (50) and the second connecting piece (30) are separate structures; or, the first cover plate (40) and the first connecting piece (20) are separate structures, and the second cover plate (50) and the second connecting piece (30) are an integral structure.

5. The battery structure according to claim 3, characterized in that, The housing is a cylindrical structure with openings at both ends. The first cover plate (40) is placed on one of the two openings and connected to the housing, and the second cover plate (50) is placed on the other of the two openings and connected to the housing.

6. The battery structure according to any one of claims 1 to 5, characterized in that, The first core (11) is provided with a plurality of first adhesive tapes (111), which are spaced apart along the circumference of the first core (11). The second core (12) is provided with a plurality of second adhesive tapes (121), which are spaced apart along the circumference of the second core (12).

7. The battery structure according to claim 6, characterized in that, The first tape (111) and / or the second tape (121) are provided with a plurality of through holes.

8. The battery structure according to any one of claims 1 to 5, characterized in that, The dual-core structure (10) further includes a positive electrode (60) having a first active material region (61).

9. The battery structure according to claim 8, characterized in that, The dual-core structure (10) further includes a negative electrode sheet, which has a second active material region. The first active material region (61) is correspondingly arranged with the second active material region and can cover the first active material region (61).

10. The battery structure according to any one of claims 1 to 5, characterized in that, The first electrode group (13) includes a plurality of first electrodes stacked along its own thickness direction, and the second electrode group (14) includes a plurality of second electrodes stacked along its own thickness direction. The first electrodes are positive electrodes and the second electrodes are negative electrodes.

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