Roll core structure and battery
By designing an overlapping arrangement of positive and negative tabs in the core structure, the penetration gap is increased, which solves the problem of poor electrolyte wettability and improves the performance and safety of the battery.
Patent Information
- Application Number
- CN202423311302.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2034-12-30
AI Technical Summary
The electrolyte has poor wettability in the existing core structure, which easily leads to lithium plating and affects battery performance.
Design a core structure in which the positive and negative tabs are at least partially overlapped in the height direction of the core body to form an overlapping area, thereby increasing the penetration gap and ensuring that the electrolyte can penetrate the positive and negative tabs more easily, thus improving wettability.
By increasing the penetration gap, the wettability of the electrolyte is improved, the risk of lithium plating in the middle of the core structure is reduced, and the stability and safety of the battery are enhanced.
Smart Images
Figure CN223898326U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of lithium battery technology, and in particular to a core structure and battery. Background Technology
[0002] A wound battery is a common type of battery, consisting of a wound structure, a casing, and an electrolyte. The wound structure is formed by winding positive and negative electrode sheets and positive and negative electrode tabs. After winding, the positive and negative electrode tabs are positioned opposite each other along the width direction of the positive and negative electrode sheets and located within the wound layers. This creates permeation gaps within the wound layers, allowing the electrolyte to permeate to the positive and negative electrode tabs and ensuring normal battery operation.
[0003] The existing core structure has the following drawbacks: the size of the permeation gap is limited, the electrolyte wettability is poor, and it is easy to cause lithium plating in the battery, which may lead to insufficient battery power. Utility Model Content
[0004] The technical problem to be solved by this utility model embodiment is to provide a core structure and battery to solve the problem of poor electrolyte wettability in the prior art.
[0005] The core structure provided in this embodiment of the utility model includes: a core body comprising a positive electrode sheet, a negative electrode sheet, and a separator, wherein the separator is sandwiched between the positive electrode sheet and the negative electrode sheet, and the positive electrode sheet, the negative electrode sheet, and the separator are wound together to form the core body; a positive electrode tab disposed at one end of the core body in the height direction and located at the middle of the positive electrode sheet in the winding direction, one end of the positive electrode tab being connected to the positive electrode sheet, the portion of the positive electrode tab connected to the positive electrode sheet forming a positive connection portion, the positive connection portion being located between the positive electrode sheet and the separator, and the positive electrode... The other end of the ear extends out of the core body to form a positive extension portion; the negative ear is disposed at the other end of the core body in the height direction and is located in the middle of the negative electrode sheet in the winding direction, one end of the negative ear is connected to the negative electrode sheet, the portion of the negative ear connected to the negative electrode sheet forms a negative connection portion, the negative connection portion is located between the negative electrode sheet and the diaphragm, and the other end of the negative ear extends out of the core body to form a negative extension portion; in the height direction of the core body, the positive connection portion and the negative connection portion are at least partially overlapped to form an overlapping area.
[0006] Optionally, the ratio of the height of the core body to the inner diameter of the core body is greater than or equal to 2.
[0007] Optionally, the positive electrode at the positive connection portion is a positive electrode groove region without positive electrode active material; along the width direction of the positive electrode, the positive electrode groove region is a through groove penetrating the positive electrode.
[0008] Optionally, the negative electrode at the negative connection portion is a negative electrode groove region without negative electrode active material; along the width direction of the negative electrode, the negative electrode groove region is a through groove penetrating the negative electrode.
[0009] This utility model also discloses a battery, including the winding core structure as described above.
[0010] Optionally, the battery is one of a square battery and a cylindrical battery.
[0011] Compared with the prior art, the beneficial effects of the core structure provided by this utility model embodiment are as follows: the core structure includes a core body, a positive electrode tab, and a negative electrode tab. The core body includes a positive electrode sheet, a negative electrode sheet, and a separator, with the separator sandwiched between the positive electrode sheet and the negative electrode sheet, and the positive electrode sheet, the negative electrode sheet, and the separator are wound together to form the core body. A positive electrode tab is located at one end of the core body in the height direction and at the middle of the positive electrode sheet in the winding direction. One end of the positive electrode tab is connected to the positive electrode sheet, and the part where the positive electrode tab is connected to the positive electrode sheet forms a positive connection portion. The positive connection portion is located between the positive electrode sheet and the separator. The other end of the positive electrode tab extends out of the core body to form a positive extension portion. A negative electrode tab is located at the other end of the core body in the height direction and at the middle of the negative electrode sheet in the winding direction. One end of the negative electrode tab is connected to the negative electrode sheet, and the part where the negative electrode tab is connected to the negative electrode sheet forms a negative connection portion. The negative connection portion is located between the negative electrode sheet and the separator. The other end of the negative electrode tab extends out of the core body to form a negative extension portion. In the height direction of the core body, the positive connection portion and the negative connection portion at least partially overlap to form an overlapping area. Since the positive connection portion and the negative connection portion are at least partially overlapped, the penetration gap formed by the positive and negative electrodes in the core body can be increased, allowing the electrolyte to more easily penetrate into the positive and negative electrodes in the core body from both ends of the penetration gap. This ensures that the electrolyte can fully wet the positive and negative electrodes, thereby effectively reducing the risk of lithium plating in the middle of the core structure. Attached Figure Description
[0012] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. In the accompanying drawings:
[0013] Figure 1 This is a three-dimensional schematic diagram of the core structure in the convolution state provided in this embodiment of the utility model;
[0014] Figure 2 This is a schematic diagram of the negative electrode sheet and negative electrode tab provided in an embodiment of the present utility model;
[0015] Figure 3 This is a schematic diagram of the negative electrode sheet provided in an embodiment of the present utility model;
[0016] Figure 4This is a schematic diagram of the positive electrode plate and positive electrode tab provided in an embodiment of the present invention;
[0017] Figure 5 This is a schematic diagram of the positive electrode sheet provided in an embodiment of the present utility model;
[0018] Figure 6 This is a schematic diagram of the core structure in the unfolded state provided in this embodiment of the utility model;
[0019] Figure 7 This is a 3D schematic diagram of the existing core structure in its convolution state;
[0020] Figure 8 This is a schematic diagram of the existing core structure in its unfolded state.
[0021] The labels for the attached figures are as follows:
[0022] 100. Core structure;
[0023] 1. Core body; 11. Positive electrode sheet; 111. First current collector area; 112. Positive electrode groove area; 12. Negative electrode sheet; 121. Second current collector area; 122. Negative electrode groove area; 2. Positive electrode tab; 21. Positive connection part; 22. Positive extension part; 3. Negative electrode tab; 31. Negative connection part; 32. Negative extension part; 4. Overlapping area; 5. Penetration gap. Detailed Implementation
[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The preferred embodiments of this utility model will now be described in detail with reference to the accompanying drawings.
[0025] This utility model embodiment provides a core structure 100, such as... Figures 1 to 6 As shown, the core structure 100 of this utility model includes a core body 1, a positive electrode tab 2, and a negative electrode tab 3. The core body 1 includes a positive electrode sheet 11, a negative electrode sheet 12, and a separator. The separator is sandwiched between the positive electrode sheet 11 and the negative electrode sheet 12, and the positive electrode sheet 11, the negative electrode sheet 12, and the separator (not shown) are wound together to form the core body 1. The positive electrode tab 2 is located in the height direction of the core body 1. Figure 1 One end of the positive electrode 11 in the X direction, and located in the winding direction (in the X direction). Figure 6In the Z direction, at the middle, one end of the positive electrode tab 2 is connected to the positive electrode sheet 11, and the part where the positive electrode tab 2 is connected to the positive electrode sheet 11 forms a positive connection portion 21. The positive connection portion 21 is located between the positive electrode sheet 11 and the diaphragm. The other end of the positive electrode tab 2 extends out of the core body 1 to form a positive extension portion 22. The negative electrode tab 3 is provided at the other end in the height direction of the core body 1 and is located in the middle of the negative electrode sheet 12 in the winding direction. One end of the negative electrode tab 3 is connected to the negative electrode sheet 12, and the part where the negative electrode tab 3 is connected to the negative electrode sheet 12 forms a negative connection portion 31. The negative connection portion 31 is located between the negative electrode sheet 12 and the diaphragm. The other end of the negative electrode tab 3 extends out of the core body 1 to form a negative extension portion 32. In the height direction of the core body 1, the positive connection portion 21 and the negative connection portion 31 are at least partially overlapped to form an overlapping area 4.
[0026] Specifically, the positive electrode tab 2 is located at one end of the core body 1 in the height direction and at the middle of the positive electrode sheet 11 in the winding direction, and the negative electrode tab 3 is located at the other end of the core body 1 in the height direction and at the middle of the negative electrode sheet 12 in the winding direction. This ensures that the positive electrode tab 2 and the negative electrode tab 3 can be connected with the middle layer of the positive electrode sheet 11, the negative electrode sheet 12 and the separator core body 1, thereby increasing the stability of the core structure 100 and helping to optimize the performance of the battery.
[0027] Furthermore, a separator is sandwiched between the positive electrode 11 and the negative electrode 12. The portion of the positive electrode tab 2 connected to the positive electrode 11 forms a positive connection portion 21, which is located between the positive electrode 11 and the separator. The portion of the negative electrode tab 3 connected to the negative electrode 12 forms a negative connection portion 31, which is located between the negative electrode 12 and the separator. Thus, the separator effectively isolates the positive and negative electrodes, preventing short circuits within the core structure 100 and ensuring battery safety.
[0028] It is worth mentioning that the other end of the positive electrode 2 extends out of the core body 1 to form a positive epitaxial portion 22, and the other end of the negative electrode 3 extends out of the core body 1 to form a negative epitaxial portion 32. Thus, the positive epitaxial portion 22 and the negative epitaxial portion 32 can be exposed at both ends of the core body 1, which facilitates the connection of the positive electrode 2 and the negative electrode 3 with the circuit outside the core structure 100.
[0029] More specifically, since the positive connection portion 21 and the negative connection portion 31 are at least partially overlapped in the height direction of the core body 1, ensuring that the positive connection portion 21 and the negative connection portion 31 can overlap to form an overlapping area 4, the penetration gap 5 formed by the positive electrode tab 2 and the negative electrode tab 3 in the core body 1 can be increased. This allows the electrolyte located outside the core structure 100 to more easily penetrate from both ends of the penetration gap 5 after the core structure 100 is assembled into a battery. Figure 1The positive electrode tab 2 and negative electrode tab 3 (both ends in the X and Y directions) are penetrated into the core body 1 to ensure that the electrolyte can fully wet the positive electrode tab 2 and negative electrode tab 3, thereby effectively reducing the risk of lithium plating in the middle of the core structure 100.
[0030] Understandably, such as Figures 7 to 8 As shown, in the existing core structure 100, since the positive electrode tab 2 and the negative electrode tab 3 are respectively arranged opposite to each other along the width direction of the positive electrode sheet 11 and the negative electrode sheet 12 and are located in the winding layer of the positive electrode sheet 11 and the negative electrode sheet 12, the penetration gap 5 formed in its winding layer is only the thickness of one positive electrode tab 2 or one negative electrode tab 3. However, in the core structure 100 of this utility model, the positive connection portion 21 of the positive electrode tab 2 and the negative connection portion 31 of the negative electrode tab 3 are located between the positive electrode sheet 11 and the negative electrode sheet 12 and are at least partially overlapped. Therefore, the penetration gap 5 formed by the positive electrode tab 2 and the negative electrode tab 3 in the core structure 100 can be increased to the sum of the thicknesses of the positive electrode tab 2 and the negative electrode tab 3, so that the electrolyte can more easily penetrate into the positive electrode tab 2 and the negative electrode tab 3 in the core structure 100 from both ends of the penetration gap 5, effectively improving the wettability of the electrolyte.
[0031] Furthermore, as one specific implementation method in some embodiments of this utility model, such as Figures 1 to 6 As shown, the ratio of the height of the core body 1 to the inner diameter of the core body 1 is greater than or equal to 2.
[0032] Specifically, by setting the ratio of the height of the core body 1 to the inner diameter of the core body 1 to be greater than or equal to 2, the core structure 100 can maintain an appropriate size, avoid the cross area of the core structure 100 being too large, and at the same time have sufficient height to allow the positive electrode tab 2 to be provided with the positive extension portion 22 and the negative electrode tab 3 to be provided with the negative connection portion 31.
[0033] Furthermore, as one specific implementation method in some embodiments of this utility model, such as Figure 5 As shown, the positive electrode 11 at the positive connection 21 is a positive electrode groove region 112 that does not contain positive electrode active material; along the width direction of the positive electrode 11, the positive electrode groove region 112 is a through groove that penetrates the positive electrode 11.
[0034] Specifically, a first current collector 111 is provided on the positive electrode 11, and the first current collector 111 is coated with a positive electrode active material so that ions in the electrolyte can fully undergo electrochemical reactions, thereby realizing the storage and release of battery energy. The positive electrode 11 at the positive connection portion 21 in the first current collector 111 is a positive electrode recessed region 112 without positive electrode active material, so that the positive connection portion 21 of the positive electrode tab 2 can be connected to the positive electrode 11, and the reliability of the electrical connection between the positive electrode tab 2 and the positive electrode 11 is ensured. Furthermore, since the positive electrode recessed region 112 is a through groove penetrating the positive electrode 11 along the width direction of the positive electrode 11, the positive electrode recessed region 112 can be formed by using a skip coating process when setting the first current collector 111, thus avoiding the need for laser cleaning of the positive electrode active material coated at the corresponding positive electrode recessed region 112 position in the first current collector 111, thereby reducing costs.
[0035] It should be noted that the length of the positive electrode groove region 112 can be adjusted adaptively, as long as it is greater than or equal to the length of the positive connection part 21.
[0036] Furthermore, as one specific implementation method in some embodiments of this utility model, such as Figure 5 As shown, the negative electrode 12 at the negative connection portion 31 is a negative electrode groove region 122 without negative electrode active material; along the width direction of the negative electrode 12, the negative electrode groove region 122 is a through groove penetrating the negative electrode 12.
[0037] Specifically, a second current collector 121 is provided on the negative electrode 12, and the second current collector 121 is coated with a negative electrode active material so that ions in the electrolyte can fully undergo electrochemical reactions, thereby realizing the storage and release of battery energy. The negative electrode 12 at the negative connection portion 31 in the second current collector 121 is a negative electrode recessed region 122 without negative electrode active material, so that the negative connection portion 31 of the negative electrode tab 3 can be connected to the negative electrode 12, and the reliability of the electrical connection between the negative electrode tab 3 and the negative electrode 12 is ensured. Furthermore, since the negative electrode recessed region 122 is a through groove that penetrates the negative electrode 12 along the width direction of the negative electrode 12, the negative electrode active material can be applied in a skip-coating process to form the negative electrode recessed region 122 when the second current collector 121 is provided, thus avoiding the need for laser cleaning of the negative electrode active material coated at the corresponding position of the negative electrode recessed region 122 in the second current collector 121, thereby reducing costs.
[0038] It should be noted that the length of the negative electrode groove region 122 can be adjusted adaptively, as long as it is greater than or equal to the length of the negative connection part 31.
[0039] This utility model also discloses a battery, including the wound core structure 100 as described above. The beneficial effects of the battery using the wound core structure 100 have been explained in the description of the wound core structure 100 above, and will not be repeated here. Preferably, the battery is one of a square battery and a cylindrical battery. It should be noted that the battery of this utility model is not limited to square batteries and cylindrical batteries, and its specific shape can be adaptively adjusted.
[0040] It should be understood that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some of the technical features; and all such modifications and substitutions should fall within the protection scope of the appended claims of this utility model.
Claims
1. A core structure, characterized in that, include: The core body includes a positive electrode sheet, a negative electrode sheet, and a separator, wherein the separator is sandwiched between the positive electrode sheet and the negative electrode sheet, and the positive electrode sheet, the negative electrode sheet, and the separator are wound together to form the core body; A positive electrode tab is provided at one end of the core body in the height direction and located in the middle of the positive electrode sheet in the winding direction. One end of the positive electrode tab is connected to the positive electrode sheet. The part of the positive electrode tab connected to the positive electrode sheet forms a positive connection part. The positive connection part is located between the positive electrode sheet and the diaphragm. The other end of the positive electrode tab extends out of the core body to form a positive epitaxial part. A negative electrode tab is provided at the other end of the core body in the height direction and is located in the middle of the negative electrode sheet in the winding direction. One end of the negative electrode tab is connected to the negative electrode sheet. The part of the negative electrode tab connected to the negative electrode sheet forms a negative connection part. The negative connection part is located between the negative electrode sheet and the diaphragm. The other end of the negative electrode tab extends out of the core body to form a negative epitaxial part. In the height direction of the core body, the positive connecting portion and the negative connecting portion are at least partially overlapped to form an overlapping area.
2. The core structure according to claim 1, characterized in that, The ratio of the height of the core body to the inner diameter of the core body is greater than or equal to 2.
3. The core structure according to claim 1, characterized in that, The positive electrode at the positive connection portion is a positive electrode groove region without positive electrode active material; along the width direction of the positive electrode, the positive electrode groove region is a through groove penetrating the positive electrode.
4. The core structure according to claim 1, characterized in that, The negative electrode at the negative connection portion is a negative electrode groove region without negative electrode active material; along the width direction of the negative electrode, the negative electrode groove region is a through groove penetrating the negative electrode.
5. A battery, characterized in that, Includes the core structure as described in any one of claims 1-4.
6. The battery according to claim 5, characterized in that, The battery is one of a square battery or a cylindrical battery.