A cell structure and a stacked battery

Abstract

This invention belongs to the field of secondary battery technology and mainly relates to a cell structure. The cell structure includes a positive electrode, a separator, and a negative electrode arranged sequentially. The positive electrode extends with a positive empty foil section, and the negative electrode has a negative empty foil section. The positive and negative empty foil sections are used to charge and discharge the cell structure. The positive electrode also has a first empty foil region, or the negative electrode also has a second empty foil region. The first and second empty foil regions are also used to charge and discharge the cell structure. This solves the technical defect in existing cell structures where the charging and discharging capacity of the cell fails or weakens after the positive and negative empty foil sections break. In addition, this application also designs a stacked battery, which further improves the drop resistance of the stacked battery.

Description

Technical Field

[0001] The invention belongs to the field of secondary battery technology, specifically relating to a cell structure and a stacked battery. Background Technology

[0002] With the rapid development of industries such as electric vehicles and new energy storage, battery technology has gradually become an important support for energy storage and conversion. As a mainstream structure of lithium-ion batteries, stacked batteries are widely used in various battery products due to their advantages such as high energy density, long lifespan, and low internal resistance. In particular, L-type stacked batteries are widely used in many fields. L-type stacked batteries, through the stacking of positive electrode plates, negative electrode plates, and separators, can effectively improve the energy density of the cells and the overall battery performance.

[0003] In existing laminated battery processes, the empty foil areas of each electrode layer need to be welded together or to the tab components to enable current input and output. However, due to welding processes and potential drops or compression during actual use, the empty foil areas are prone to breakage during welding and drop folding, especially at the connection points with the tabs. Once the empty foil area breaks, the corresponding electrode layer will directly lose its charging and discharging capability, severely affecting the overall performance of the battery cell.

[0004] Therefore, it is urgent to improve the existing cell structure and stacked battery to solve the defects of the aforementioned technologies. Summary of the Invention

[0005] One of the objectives of this invention is to provide a cell structure that allows the electrode to continue charging and discharging even after the electrode foil area breaks, addressing the shortcomings of existing technologies.

[0006] To achieve the above-mentioned objectives, this application implements the following technical solution:

[0007] A battery cell structure includes a positive electrode sheet, a separator, and a negative electrode sheet arranged sequentially. The positive electrode sheet extends with a positive empty foil section, and the negative electrode sheet has a negative empty foil section. The positive and negative empty foil sections are used to power the battery cell structure for charging and discharging. The positive electrode sheet also has a first empty foil region, or the negative electrode sheet also has a second empty foil region. The first and second empty foil regions are also used to power the battery cell structure for charging and discharging.

[0008] The above technical solution has produced the following technical effects:

[0009] To address the issue of electrode tab breakage in existing battery cells, this application proposes a novel battery cell structure design. By incorporating a first empty foil region and a second empty foil region on the positive and negative electrode plates, the battery cell can continue charging and discharging even after the empty foil sections of the positive and negative electrodes break. Specifically, this application adds empty foil regions to each layer of the electrode plates, forming multiple welding points. Through a rational arrangement of the welding structure, the technical defect of battery cell failure due to empty foil sections of the positive and negative electrodes is avoided. Simultaneously, by adding a new set of welding structures (i.e., the first and second empty foil regions), the internal temperature rise and resistance of the battery cell are effectively reduced, and the safety of the battery cell is significantly improved.

[0010] As a further improvement to the battery cell structure of the present invention, the positive electrode includes a first bent portion and two first body portions that are connected by the first bent portion.

[0011] The negative electrode sheet includes a second bending portion and two second body portions that are connected through the second bending portion;

[0012] The diaphragm includes a third bend and two third body sections that are connected by transition through the third bend.

[0013] As a further improvement to the battery cell structure of the present invention, a first empty foil area is disposed in the first bending portion, and a second empty foil area is disposed in the second bending portion.

[0014] As a further improvement to the battery cell structure of the present invention, when the positive electrode sheet is provided with a first empty foil area, the negative electrode sheet is provided with a first notch corresponding to the first empty foil area, and the separator is provided with a second notch corresponding to the first empty foil area.

[0015] As a further improvement to the battery cell structure of the present invention, when the negative electrode sheet is provided with a second empty foil area, the positive electrode sheet is provided with a third notch corresponding to the second empty foil area, and the separator is provided with a second notch corresponding to the second empty foil area.

[0016] The second objective of this invention is to provide a stacked battery that addresses the shortcomings of existing technologies and solves the technical defect that the internal charging and discharging capabilities of existing stacked batteries fail or weaken after a drop.

[0017] To achieve the above-mentioned objectives, this application implements the following technical solution:

[0018] A laminated battery cell includes any of the above-mentioned cell structures, including at least two cell structures containing a first empty foil region and / or at least two cell structures containing a second empty foil region;

[0019] The first empty foil area is welded to the adjacent first empty foil area to form a first connector; the second empty foil area is welded to the adjacent second empty foil area to form a second connector.

[0020] The above technical solution produces the following technical effects:

[0021] This application's stacked battery, by incorporating a first connector and a second connector, allows the battery to disperse stress through multiple welding points when subjected to external impact, thereby improving its impact resistance. Simultaneously, the increased number of welding points diversifies the internal current path, ensuring that even if some welding points break, the battery can still maintain its charging and discharging function through the remaining weld points. Furthermore, the optimized welding structure effectively reduces the internal temperature rise of the battery, improving its thermal stability.

[0022] As a further improvement to the stacked battery cell of the present invention, the stacked battery cell also includes a packaging film for assembling the stacked battery cell.

[0023] As a further improvement to the stacked battery cell of the present invention, the first connector and the second connector are provided with cutting areas.

[0024] As a further improvement to the stacked battery cell of the present invention, when the stacked battery cell is provided with only a first connector, hot melt adhesive is applied to both sides of the first connector along the thickness direction; when the stacked battery cell is provided with only a second connector, hot melt adhesive is applied to both sides of the second connector along the thickness direction.

[0025] As a further improvement to the stacked battery cell of the present invention, when the stacked battery cell includes both a first connector and a second connector, the surface of the first connector or the second connector closest to the packaging film along the thickness direction of the stacked battery cell is coated with hot melt adhesive. Attached Figure Description

[0026] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0027] Figure 1 This is one of the schematic diagrams of the battery cell structure in Embodiment 1 of the present invention;

[0028] Figure 2 This is one of the schematic diagrams of the positive electrode structure in Embodiment 1 of the present invention;

[0029] Figure 3 This is one of the schematic diagrams of the negative electrode structure in Embodiment 1 of the present invention;

[0030] Figure 4 This is a schematic diagram of the diaphragm structure in Embodiment 1 of the present invention;

[0031] Figure 5 This is a second schematic diagram of the battery cell structure in Embodiment 1 of the present invention;

[0032] Figure 6 This is a second schematic diagram of the negative electrode structure in Embodiment 1 of the present invention;

[0033] Figure 7 This is a second schematic diagram of the positive electrode structure in Embodiment 1 of the present invention;

[0034] Figure 8 This is one of the schematic diagrams of the stacked battery structure in Embodiment 3 of the present invention;

[0035] Figure 9 This is a second schematic diagram of the stacked battery structure in Embodiment 3 of the present invention;

[0036] Figure 10 for Figure 9 Cross-sectional view along A-A;

[0037] in:

[0038] 1 - Cell structure;

[0039] 11 - Positive electrode plate;

[0040] 111 – Positive electrode empty foil section;

[0041] 112 – First empty foil area;

[0042] 113 – First bend;

[0043] 114-The first body part;

[0044] 115 – The third gap;

[0045] 12 - Diaphragm;

[0046] 121 – Third bend;

[0047] 122 – Third Body Section;

[0048] 123 – Second Gap;

[0049] 13 - Negative electrode plate;

[0050] 131 – Negative electrode empty foil section;

[0051] 132 – Second empty foil area;

[0052] 133 – Second bend;

[0053] 134 – Second Body Section;

[0054] 135 – First Gap;

[0055] 2 - First connector;

[0056] 21 - Cutting area;

[0057] 3 – Second connector;

[0058] 4 - Packaging film;

[0059] 5 - Hot melt adhesive. Detailed Implementation

[0060] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terminology used in the specification of this application is for the purpose of describing specific embodiments only and is not intended to limit this application.

[0061] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0062] Although this application discloses preferred embodiments as described above, it is not intended to limit the claims. Any person skilled in the art can make several possible changes and modifications without departing from the concept of this application. Therefore, the scope of protection of this application should be determined by the scope defined in the claims of this application.

[0063] The present invention will be further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0064] Example 1

[0065] like Figure 1As shown in Figure 7, in order to solve the problem of battery charging and discharging function being damaged due to drops in the prior art, the present invention improves the stacked cell structure 1 in the battery. Specifically, the cell structure 1 in this application includes a positive electrode 11, a separator 12, and a negative electrode 13 arranged in sequence. The positive electrode 11 extends with a positive empty foil section 111, and the negative electrode 13 is provided with a negative empty foil section. The positive empty foil section 111 and the negative empty foil section are used to charge and discharge the cell structure 1. The positive electrode 11 is also provided with a first empty foil area 112, or the negative electrode 13 is also provided with a second empty foil area 132. The first empty foil area 112 and the second empty foil area 132 are also used to charge and discharge the cell structure 1.

[0066] Specifically, by providing a first empty foil region 112 on the positive electrode 11 and a second empty foil region 132 on the negative electrode 13, the internal current path of the battery can be increased, allowing the battery to maintain normal charging and discharging functions through other solder joints even if some solder joints break. This design significantly improves the battery's shock resistance and reliability, ensuring stable operation under harsh conditions. Furthermore, when the first empty foil region 112 is welded to itself / the second empty foil region 132 is welded to itself to form an additional welded structure, stress can be dispersed by multiple solder joints when the battery is subjected to external impact, effectively protecting the internal structure of the battery from damage.

[0067] It is worth noting that the above-mentioned technical solutions of this application include two cases: a cell structure 1 with a positive electrode 11 having a first empty foil region 112 and a cell structure 1 with a negative electrode 13 having a second empty foil region 132. In specific implementation, the stacked battery prepared by the cell structure 1 of this application can be formed by stacking multiple cell structures 1 including the positive electrode 11 having the first empty foil region 112 or by stacking multiple cell structures 1 including the negative electrode 13 having the second empty foil region 132; in addition, the stacked battery prepared by the cell structure 1 of this application can also be formed by stacking multiple cell structures 1 including the positive electrode 11 having the first empty foil region 112 and multiple cell structures 1 including the negative electrode 13 having the second empty foil region 132.

[0068] Specifically, by setting additional welding points (first empty foil area 112 and second empty foil area 132) in the cell structure 1, this application not only enhances the mechanical strength of the battery, but also reduces the local overheating caused by current concentration by dispersing the current path, thereby effectively reducing the internal temperature rise of the battery and improving the thermal stability of the battery.

[0069] In summary, by setting an additional empty foil area in the cell structure 1 and optimizing the welding structure, the present invention not only improves the impact resistance and reliability of the battery, but also effectively reduces the internal temperature rise of the battery and improves the thermal stability of the battery.

[0070] Example 2

[0071] like Figure 1 As shown in Figure 7, unlike Embodiment 1, in order to further reduce the influence of the first empty foil region 112 and the second empty foil region 132 on the size of the cell structure 1, the positive electrode 11 further includes a first bending portion 113 and two first body portions 114 connected by the first bending portion 113; the negative electrode 13 includes a second bending portion 133 and two second body portions 134 connected by the second bending portion 133; the separator 12 includes a third bending portion 121 and two third body portions 122 connected by the third bending portion 121.

[0072] Specifically, the positive electrode 11 achieves an L-shaped structure through the first bending portion 113 and the first body portion 114, the negative electrode 13 achieves an L-shaped structure through the second bending portion 133 and the second body portion 134, and the separator 12 achieves an L-shaped structure through the third bending portion 121 and the third body portion 122. This design allows the cell structure 1 to maintain its original function while adapting to a more compact spatial layout, thereby achieving higher energy density without increasing the overall size of the battery. Furthermore, through the L-shaped structure design, the bending portion of the cell structure 1 can act as a buffer when subjected to external impact, reducing the damage to the internal structure of the cell from direct impact. At the same time, due to the presence of the bending portion, the cell structure 1 can be stacked more tightly, further improving the volume utilization rate of the battery, which is of great significance for improving the energy density of the battery.

[0073] Furthermore, the first empty foil area 112 is disposed in the first bend 113, and the second empty foil area 132 is disposed in the second bend 133. As shown in the figure, both the first empty foil area 112 and the second empty foil area 132 are arc-shaped and located inside the first bend 113 and the second bend 133, respectively. Therefore, during the cell manufacturing process, the arc-shaped design of the first empty foil area 112 and the second empty foil area 132 allows for a reasonable layout of the solder joints, thereby avoiding stress concentration on the internal structure of the cell. This layout ensures that the solder joints do not negatively affect the performance of the cell, while maintaining the structural strength and stability of the cell. In addition, since the solder joints are located inside the bend, they do not increase the thickness of the cell, thus not affecting the volume utilization rate of the battery. Furthermore, the improvements to the cell structure 1 described above in this application do not affect the thickness or capacity of the stacked battery prepared according to the cell structure 1 due to the additional solder joints (first empty foil area 112 and second empty foil area 132).

[0074] Furthermore, when the positive electrode 11 has a first empty foil area 112, the negative electrode 13 has a first notch 135 corresponding to the first empty foil area 112, and the separator 12 has a second notch 123 corresponding to the first empty foil area 112. This design allows the first empty foil area 112 to be welded to the first empty foil area 112 of the adjacent positive electrode 11 of the cell structure 1 via the first notch 135 and the second notch 123. In addition, when the cell structure 1 of this application is subjected to external impact, the first notch 135 and the second notch 123 can serve as stress relief areas, allowing the cell to deform to a certain extent without affecting the integrity of the overall structure. This design not only improves the mechanical strength of the battery but also enhances its safety performance in harsh environments. Simultaneously, the notch design allows for more flexible cell stacking, adapting to different spatial layouts and further optimizing the battery's volume utilization.

[0075] Furthermore, when the negative electrode 13 has a second empty foil area 132, the positive electrode 11 has a third notch 115 corresponding to the second empty foil area 132, and the separator 12 has a second notch 123 corresponding to the second empty foil area 132. Through this design, the second empty foil area 132 and the second empty foil area 132 of the adjacent negative electrode 13 of the cell structure 1 are welded together via the third notch 115 and the second notch 123. This design also allows the cell to release stress through the notch when subjected to external impact, thereby protecting the cell structure 1 from damage. Simultaneously, the presence of the notch also makes the cell more adaptable during stacking, allowing adjustments according to different space requirements, further improving the battery's volume utilization rate.

[0076] In summary, by introducing bending and notch designs into the cell structure 1, this invention not only improves the battery's impact resistance and safety but also optimizes its volume utilization, thus without increasing the overall battery size. Furthermore, when the battery is subjected to external impact, the arc shape of the bending portion effectively disperses stress, reducing stress concentration and protecting the cell structure 1 from damage. Moreover, due to the arc shape design of the first empty foil area 112 and the second empty foil area 132, they can form more uniform and stable weld points during welding, further improving the battery's reliability and safety.

[0077] Other aspects that are the same as in Implementation Method 1 will not be described again in this implementation method.

[0078] Example 3

[0079] like Figure 1As shown in Figure 10, unlike Example 1, in order to mitigate the change in the charging and discharging performance of existing stacked batteries after being subjected to external forces, this application also designs a stacked battery cell. The stacked battery cell includes any of the above-mentioned cell structures 1, including at least two cell structures 1 containing a first empty foil region 112 and / or at least two cell structures 1 containing a second empty foil region 132; wherein, the first empty foil region 112 is welded to an adjacent first empty foil region 112 to form a first connector 2; the second empty foil region 132 is welded to an adjacent second empty foil region 132 to form a second connector 3.

[0080] Specifically, the design of the first connector 2 and the second connector 3 allows the stacked cell to disperse stress through multiple welding points when subjected to external impact, thereby improving the battery's impact resistance. Simultaneously, the increased number of welding points diversifies the internal current path of the battery. Even if the welding point at the tab breaks under external force, the battery can still maintain its charging and discharging function through other welding points. Furthermore, the stacked cell of this application effectively reduces the internal temperature rise of the battery and improves its thermal stability through optimized welding structure. This design not only ensures stable operation of the battery under harsh conditions but also improves battery safety performance and reduces safety hazards caused by excessive temperature.

[0081] Furthermore, the stacked battery cell also includes a packaging film 4, which is used to assemble the stacked battery cell. In this specific embodiment, the packaging film 4 is an aluminum-plastic film structure. The aluminum-plastic film structure of the packaging film 4 not only provides good sealing performance to prevent leakage of chemical substances inside the battery, but also provides a certain degree of mechanical protection, reducing damage to the battery from the external environment. In addition, the use of aluminum-plastic film also gives the battery better heat resistance and corrosion resistance, thereby extending the battery's service life.

[0082] Furthermore, the first connector 2 and the second connector 3 are provided with cutting areas 21. It should be noted that this application... Figure 8 This design omits the cutting area 21, but this does not mean that the structure will not be cut later. Furthermore, this application... Figure 8 Taking the first connector 2 as an example, the welding method is electric welding; Figure 9 Taking the second connector 3 as an example, the welding method is area welding, but this does not mean that the technical solution of this application is limited to this. Figure 8 , Figure 9 As shown.

[0083] Specifically, the cutting area 21 is designed to facilitate the cutting and separation of the laminated cells during the production process to accommodate battery packs of different sizes and shapes. The cutting area 21 provides greater flexibility in the manufacturing and assembly of the laminated cells, while ensuring the structural integrity and electrical performance stability of the battery pack. In practice, the aluminum-plastic film also sometimes incorporates the cutting area 21, where the laminated cells are cut after being packaged in the aluminum-plastic film.

[0084] Furthermore, when the stacked cell only has the first connector 2, hot melt adhesive 5 is applied to both sides of the first connector 2 along the thickness direction (Y-axis direction); when the stacked cell only has the second connector 3, hot melt adhesive 5 is applied to both sides of the second connector 3 along the thickness direction (Y-axis direction). Thus, the use of hot melt adhesive 5 ensures the stability and sealing of the first connector 2 and the second connector 3 inside the battery, preventing leakage of chemical substances inside the battery, while also providing additional mechanical protection and further enhancing the battery's impact resistance.

[0085] Furthermore, when the stacked battery cell includes both a first connector 2 and a second connector 3, hot melt adhesive 5 is applied to the surface of the first connector 2 or the second connector 3 closest to the packaging film 4 along the thickness direction (Y-axis direction) of the stacked battery cell. This design not only strengthens the bonding force between the battery cell and the packaging film 4, but also improves the overall structural stability of the battery, ensuring the safety and reliability of the battery in harsh environments. It is worth noting that the above only represents different stacking methods of this application, but this application does not limit the number or arrangement of the first connector 2 and the second connector 3 of each battery cell in the stacked battery.

[0086] Other aspects that are the same as in Implementation Method 1 will not be described again in this implementation method.

[0087] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell structure, characterized in that, The battery cell includes a positive electrode (11), a separator (12), and a negative electrode (13) arranged in sequence. The positive electrode (11) extends with a positive electrode empty foil section (111), and the negative electrode (13) is provided with a negative electrode empty foil section (131). The positive electrode empty foil section (111) and the negative electrode empty foil section (131) are used to charge and discharge the battery cell structure. The positive electrode (11) is further provided with a first empty foil area (112) or the negative electrode (13) is further provided with a second empty foil area (132). The first empty foil area (112) and the second empty foil area (132) are also used for charging and discharging the battery cell structure. The positive electrode plate (11) includes a first bending portion (113) and two first body portions (114) that are connected by the first bending portion (113). The negative electrode plate (13) includes a second bending portion (133) and two second body portions (134) that are connected by the second bending portion (133). The diaphragm (12) includes a third bend (121) and two third body parts (122) that are connected by the third bend (121). The first empty foil area (112) is disposed in the first bending portion (113), and the second empty foil area (132) is disposed in the second bending portion (133).

2. The cell structure according to claim 1, characterized in that, When the positive electrode (11) is provided with a first empty foil area (112), the negative electrode (13) is provided with a first notch (135) corresponding to the first empty foil area (112), and the diaphragm (12) is provided with a second notch (123) corresponding to the first empty foil area (112).

3. The cell structure according to claim 1, characterized in that, When the negative electrode plate (13) is provided with a second empty foil area (132), the positive electrode plate (11) is provided with a third notch (115) corresponding to the second empty foil area (132), and the diaphragm (12) is provided with a second notch (123) corresponding to the second empty foil area (132).

4. A stacked battery, comprising the cell structure as described in any one of claims 1-3, characterized in that, Includes at least two cell structures containing a first empty foil region (112) and / or at least two cell structures containing a second empty foil region (132); The first empty foil area (112) is welded to the adjacent first empty foil area (112) to form a first connector (2); the second empty foil area (132) is welded to the adjacent second empty foil area (132) to form a second connector (3).

5. A stacked battery according to claim 4, characterized in that, It also includes a packaging film (4) for assembling the stacked battery.

6. A stacked battery according to claim 5, characterized in that, The first connector (2) and the second connector (3) are provided with a cutting area (21).

7. A stacked battery according to claim 6, characterized in that, When the stacked battery has only a first connector (2), hot melt adhesive (5) is applied to both sides of the first connector (2) along the thickness direction; when the stacked battery has only a second connector (3), hot melt adhesive (5) is applied to both sides of the second connector (3) along the thickness direction.

8. A stacked battery according to claim 7, characterized in that, When the stacked battery includes both a first connector (2) and a second connector (3), hot melt adhesive (5) is applied to the surface of the first connector (2) or the second connector (3) that is closest to the packaging film (4) along the thickness direction of the stacked battery.

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