A battery

Abstract

The application discloses a battery, comprising a core package body and a thickening piece, the core package body is provided with a thinned area, the thickness of the thinned area of the core package body is smaller than that of other parts; the thickening piece is connected with the core package body and is arranged opposite to the thinned area, so as to increase the thickness of the thinned area. Compared with the prior art, the application sets the thickening piece at the corresponding position of the thinned area of the core package body, compensates the thickness of the thinned area, makes the thinned area and the normal area obtain approximately consistent pressure state and compaction force distribution during the forming of the battery, and avoids the thinned area from being in a "relaxed" or insufficiently compacted state between the upper and lower pressing plates. The thickness consistency balances the ion transmission path length, significantly reduces the transmission difference of the thinned area relative to the normal area, and reduces the surface lithium precipitation and dendrite risk caused by transmission lag.

Description

Technical Field

[0001] This application relates to the field of new energy battery technology, and in particular to a battery. Background Technology

[0002] In the manufacturing process of laminated battery cells, a thinning zone (also known as a trimming zone) is typically set on the tab side to facilitate tab lead-out and welding, and to reduce the interference of the stacking thickness in this area on assembly. However, in the hot pressing process after lamination, the core package is placed on a hot press table, and two heated plates on the top and bottom heat the core package and apply pressure to achieve densification and shaping between the electrode layers. Because there is a trimming zone on the tab side and the overall target thickness of the core package tends to be uniform, the trimming zone is more prone to problems such as insufficient compaction, uneven tension, and localized relaxation under pressure compared to the normal electrode area.

[0003] During the charging and discharging process of a lithium battery, when lithium ions are transported, the transport distance in the thinned area is longer than that in the normal area. As a result, the lithium ions do not have enough time to embed into the negative electrode and are deposited on the surface of the negative electrode, causing lithium plating. Utility Model Content

[0004] In view of the shortcomings of the prior art, this application provides a battery that can improve the thickness of the thinned region and shorten the local ion transport path in the thinned region.

[0005] To achieve the above objectives, this application adopts the following technical solution: A battery includes a core pack body and a thickening member. The core pack body has a thinning area, and the thickness of the core pack body in the thinning area is less than the thickness of the rest of the core pack body. The thickening member is connected to the core pack body and is disposed opposite to the thinning area to increase the thickness of the thinning area.

[0006] In one embodiment, the battery includes an inner membrane, which includes a main body and a thickening member. The main body wraps around the core package body, and the thickening member is connected to the main body.

[0007] In one embodiment, the thickening member is integrally formed with the main body, or the thickening member is separately connected to the main body.

[0008] In one embodiment, the thickening member is connected to the side of the main body facing the core package body and protrudes from the main body in a direction close to the core package body.

[0009] In one embodiment, the thickening element is arranged around the core package body.

[0010] In one embodiment, the core package body includes multiple core packages, which are attached to each other along the thickness direction of the core package body. Each core package is provided with the thinning area, and each thinning area is connected to the thickening member.

[0011] In one embodiment, the thickness of the thickening member is 0.5mm to 2mm.

[0012] In one embodiment, the width of the thickening member is 0mm to 40mm.

[0013] In one embodiment, the battery includes a housing, and the core pack body is assembled inside the housing. The housing is used to press the thickened member against the core pack body.

[0014] The beneficial effects of this application are as follows: This application provides a battery, including a core pack body and a thickening member. The core pack body has a thinning region, and the thickness of the core pack body in the thinning region is less than the thickness of the rest of the body. The thickening member is connected to the core pack body and is disposed opposite to the thinning region to increase the thickness of the thinning region. Compared with the prior art, this application compensates for the thickness of the thinning region by setting the thickening member at the corresponding position of the thinning region in the core pack body. This allows the thinning region and the normal region to obtain approximately the same pressure state and pressure distribution during battery forming, avoiding the thinning region being in a "relaxed" or insufficiently compacted state between the upper and lower pressure plates. The thickness consistency results in a balanced ion transport path length, significantly reducing the transport difference between the thinning region and the normal region, and reducing the risk of surface lithium deposition and dendrite formation due to transport lag. Attached Figure Description

[0015] Figure 1 A schematic diagram of the structure of a core package body according to this application is shown; Figure 2 A schematic diagram of the structure of a battery according to this application is shown; Figure 3 It shows Figure 2 A cross-sectional schematic diagram of battery AA; Figure 4 Another structural schematic diagram of a core package body according to this application is shown; Figure 5 A top view schematic diagram of a core package body according to this application is shown; Figure 6 Another top view schematic diagram of a core package body of this application is shown; Reference numerals: 1. Core package body; 11. Thinning area; 12. First side surface; 13. Second side surface; 14. Core package; 2. Thickening component; 3. Inner membrane; 31. Main body. Detailed Implementation

[0016] In this application, the terms "set up," "equipped with," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0017] The terms “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0019] See Figures 1-3 This application provides a battery including a core pack body 1 and a thickening member 2. The core pack body 1 is provided with a thinning area 11, and the thickness of the core pack body 1 in the thinning area 11 is less than the thickness of the rest of the body. The thickening member 2 is connected to the core pack body 1 and is disposed opposite to the thinning area 11 to increase the thickness of the thinning area 11.

[0020] In practical applications, the core package body 1 is a battery core package 14 manufactured using a lamination process. A thinning region 11 is formed on the tab side. The thinning region 11 refers to the area where the electrode coating or interlayer stacking is thinned to facilitate tab formation or optimize assembly, resulting in a thickness reduction in the core package body 1 at the thinning region 11 that is less than the thickness of the rest of the core package 14. A thickening member 2 is connected to the core package body 1 and positioned opposite the thinning region 11, compensating for the thickness of the thinning region 11 through geometric compensation. The thickening member 2 can be sheet-like, gasket-like, or a gradient thickness structure, and its material can be compatible with the separator, electrode, or coating film. Simultaneously, the thickness compensation amount of the thickening member 2 is determined based on the thinning value of the thinning region 11 and the consistency with the target compaction, ensuring that the compensated local total thickness is essentially consistent with the normal area of ​​the core package 14.

[0021] It should be noted that the above-mentioned thickening member 2 and thinning area 11 are arranged opposite to each other, meaning that along the thickness direction of the core package body 1, the projection of the thickening member 2 can completely or nearly completely cover the thinning area 11.

[0022] Compared to existing technologies, this application compensates for the thickness of the thinned area 11 by providing a thickening member 2 at the corresponding position of the thinned area 11 in the core package body 1. This ensures that the thinned area 11 and the normal area have approximately the same pressure state and pressure distribution during battery forming, preventing the thinned area 11 from being in a "relaxed" or insufficiently compacted state between the upper and lower pressure plates. The consistent thickness leads to a balanced ion transport path length, significantly reducing the transport difference between the thinned area 11 and the normal area, and reducing the risk of surface lithium deposition and dendrite formation due to transport lag.

[0023] There are several ways to connect the thickening component 2 to the core package body 1. For details, please refer to [link / reference]. Figure 3 In one embodiment, the battery further includes an inner membrane 3, which includes a main body 31 and a thickening member 2. The main body 31 wraps around the core package body 1, and the thickening member 2 is connected to the main body 31.

[0024] In practical applications, the inner membrane 3 is usually the covering membrane of the core package body 1. The inner membrane 3 is composed of the main body 31 and the thickening member 2. After the core package body 1 completes the lamination process, the main body 31 is used to wrap the core package body 1 around the entire circumference to achieve basic electrical insulation, isolation and shape retention functions. The thickening member 2 is connected to the predetermined position of the main body 31 and is arranged opposite to the thinned area 11 of the core package body 1 in space to form external geometric compensation for the thinned area 11.

[0025] The thickening component 2 can be integrally formed with the main body 31, for example, through local thickening using the same material and process, or secondary extrusion / lamination. Alternatively, the thickening component 2 can be separately connected to the main body 31, for example, by bonding, hot-melt welding, or ultrasonic welding on the inner or outer side of the main body 31, with a material similar to the main body 31. By integrating the thickening component 2 onto the main body 31 of the inner membrane 3, thickness compensation and the core package 14 can be completed in the same step, simplifying the number of parts and assembly steps, and improving the alignment accuracy and compensation stability of the thinned area 11.

[0026] See again Figure 3 To describe clearly, Figure 3 for Figure 2 A cross-sectional view of battery AA; here, the example of the thickening part 2 being integrally formed with the main body 31 is used for explanation. The thickening part 2 is connected to the side of the main body 31 facing the core pack body 1 and protrudes from the main body 31 in a direction close to the core pack body 1.

[0027] In practical applications, the main body 31 is locally thickened relative to the thinned area 11, and the locally thickened part is equivalent to the thickening member 2. The thickening member 2 is located on the inner side of the main body 31, that is, the side facing the core pack body 1, and protrudes in the direction of the core pack body 1. The thickening member 2 protrudes inward so that the outer side of the main body 31 is a flat surface. From the outer surface, the thickness of the entire battery is uniform, which facilitates battery assembly. At the same time, the thickening member 2 protrudes inward to press against the core pack body 1, so that the thinned area 11 of the core pack body 1 is squeezed, thereby improving the transmission distance of the thinned area 11.

[0028] In another embodiment, see Figure 4 The thickened part 2 can also be ringed around the core body 1.

[0029] In practical applications, the thickening component 2 may not be integrated with the inner membrane 3. The thickening component 2 is an independent component. After the core package body 1 is stacked, a thickening area is formed around the thinning area 11. The thickening component 2 is in the form of a closed ring or a near-closed frame, arranged circumferentially around the core package body 1. The circumferential thickening component 2 provides continuous geometric support and thickness compensation to the periphery of the core package body 1, achieving circumferential force homogenization from the edge to the tab side.

[0030] It should be noted that the thickening component 2 can be a single-layer uniform thickness ring with consistent thickness in all parts; or it can be a zone-differential thickening ring with inconsistent thickness in all parts. For example, the core body 1 has a first side 12 and a second side 13 arranged opposite to each other along its thickness direction. The thickening component 2 has a larger thickness on the first side 12 and the second side 13, and a smaller thickness on the other sides, so as to realize the function of directional strengthening compensation for the thinned area 11.

[0031] See Figure 5 Based on the thickening component 2 surrounding the core package body 1, the thickening component 2 surrounds the core package body 1 at least once. In practical applications, the at least one-round surround compensation establishes continuous boundary support around the entire circumference of the core package body 1, ensuring that the thinned area 11 and its adjacent areas achieve consistent clamping gap and compressive strength during hot pressing. Multiple surrounds allow for control of pressure and thickness, providing greater deformation constraint and improving long-term deformation stability.

[0032] It is understandable that the thickening component 2 can be constructed using a structure such as tape or adhesive layer.

[0033] In one embodiment, the thickness of the thickening member 2 is 0.5 mm to 2 mm. For example, the thickness of the thickening member 2 can be 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc. This application defines and describes the thickness range of the thickening member 2, that is, the thickness of the thickening member 2 is 0.5 mm to 2 mm. "Thickness" refers to the dimension of the thickening member 2 along the thickness direction of the core package body 1. This thickness range is compatible with the above-mentioned geometric arrangement of at least one loop and differential / equal thickness configuration, and can adopt a single-loop or multi-loop structure: in the case of a single loop, the thickness is the thickness of the single-loop thickening member 2; in the case of multiple loops, the thickness is the final thickness of the multi-loop thickening member 2.

[0034] In practical applications, if the thickened part 2 is too thick, it will increase the battery volume, occupy the casing space during assembly, and easily cause assembly interference problems. If the thickened part 2 is too thin, it will not adequately compensate for the thinned area 11, resulting in insufficient pressure conduction and difficulty in eliminating interlayer gaps, thus affecting ion transport. Therefore, the thickness is limited to between 0.5mm and 2mm, which avoids the problem of assembly interference while ensuring sufficient compensation for the thinned area 11.

[0035] In another embodiment, the width of the thickening member 2 is 0mm to 40mm. For example, the width of the thickening member 2 can be 10mm, 15mm, 20mm, 25mm, 30mm, etc. This application defines and describes the width of the thickening member 2. To adapt to the requirements of different core package 14 thinning amounts, it is preferable to use the width as a continuously adjustable parameter: when the thinning area 11 is small, a small width of 10mm can be used; for large-size cells, a larger width of 30mm or 40mm can be used.

[0036] In practical applications, if the thickened component 2 is too narrow, it cannot cover the actual required stress / thinning area 11, and uneven compaction and voids remain at the edges and corners. If the thickened component 2 is too wide, it occupies too much space and reduces the volumetric energy density. Therefore, limiting the width of the thickened component 2 within the above-mentioned range ensures that the thickened component 2 provides sufficient support while avoiding its impact on the overall energy density of the battery.

[0037] It should be noted that the “width” of the thickening part 2 usually refers to the length of the thickening part 2 along the height direction of the core package body 1.

[0038] See Figure 6 The core package body 1 includes multiple core packages 14. Along the thickness direction of the core package body 1, the multiple core packages 14 are attached to each other. Each core package 14 is provided with a thinning area 11, and each thinning area 11 is connected to a thickening member 2.

[0039] In practical applications, the core package body 1 can be formed by stacking multiple core packages 14, each core package 14 having a thinning area 11. During the production process, a thickening element 2 can be set in the thinning area 11 of each core package 14, and then multiple core packages 14 are stacked together. This setting makes the thickness compensation more accurate, the thickening element 2 matches the corresponding thinning amount one by one, the equivalent thickness after stacking is more consistent, and a support band is formed at each layer interface, which is uniformly compacted during hot pressing, reducing micro-gaps and springback differences between layers.

[0040] In one embodiment, multiple core packages 14 can be stacked together first, and then a thickening member 2 can be provided on the core package body 1. With this configuration, the thickening member 2 only needs to be attached or hot-pressed once, reducing multiple attachment and alignment operations, simplifying the process, reducing the number of splicing steps and intermediate inspection steps, resulting in lower material and labor input and improved production efficiency.

[0041] It should be noted that after the core package 14 is bonded, the thickening element 2 is usually located outside the thinning area 11 or at the bonding interface. Its shape, width, and thickness are matched with the thinning area 11 to form a continuous support band in the stacking direction. The thickness of the thickening element 2 is matched with the thinning amount, so that the equivalent thickness of each layer in this area remains consistent after stacking, avoiding abrupt changes in interlayer height.

[0042] In one embodiment, the battery further includes a housing, in which the core pack body 1 is assembled, and the housing is used to abut the thickened member 2 against the core pack body 1.

[0043] In practical applications, the core package body 1 is assembled inside the outer shell. During assembly and packaging, the outer shell applies a limiting and pressing effect on the core package body 1, causing the thickened component 2, located at the corresponding position of the thinning area 11 of the core package 14, to abut against the core package body 1. By providing controllable assembly pre-pressure in the thickness direction through the outer shell, the thickened component 2 is reliably pressed into the corresponding position of the thinning area 11, forming a continuous and stable force and heat conduction channel, reducing interlayer gaps, and preventing the thickened component 2 from slipping during transportation, thus ensuring the consistency of the equivalent thickness and the quality of interface contact in the compensation area.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0045] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0046] The above description is only a specific embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A battery, characterized in that, include: The core package body has a thinning area, and the thickness of the core package body in the thinning area is less than the thickness of the rest of the body; A thickening element is connected to the core package body and disposed opposite to the thinning area to increase the thickness of the thinning area.

2. The battery according to claim 1, characterized in that, The battery includes an inner membrane, which includes a main body and a thickening member. The main body wraps around the core package body, and the thickening member is connected to the main body.

3. The battery according to claim 2, characterized in that, The thickening component is integrally formed with the main body, or the thickening component is separately connected to the main body.

4. The battery according to claim 2, characterized in that, The thickening member is connected to the side of the main body facing the core package body and protrudes from the main body towards the core package body.

5. The battery according to claim 1, characterized in that, The thickening element is arranged in a ring around the core package body.

6. The battery according to claim 5, characterized in that, The thickening element surrounds the core package body at least once.

7. The battery according to claim 1, characterized in that, The core package body includes multiple core packages, which are attached to each other along the thickness direction of the core package body. Each core package is provided with the thinning area, and each thinning area is connected to the thickening member.

8. The battery according to any one of claims 1 to 7, characterized in that, The thickness of the thickened component is 0.5mm to 2mm.

9. The battery according to any one of claims 1 to 7, characterized in that, The width of the thickened part is 0mm to 40mm.

10. The battery according to any one of claims 1 to 7, characterized in that, The battery includes a housing, and the core pack body is assembled inside the housing. The housing is used to press the thickened member against the core pack body.

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