Core support structure, core structure and power battery

Abstract

The present application discloses a core support structure, a core structure and a power battery. The core support structure is used to be inserted into the central hole of the core. The core support structure includes a support column and an expansion layer disposed outside the support column. The expansion layer is configured to expand and thicken when immersed in the electrolyte to support the core. By inserting the core support structure into the central hole of the core, when the battery is filled with liquid, the expansion layer outside the support column will expand and thicken when immersed in the electrolyte, filling the gap between the core and the central hole, and supporting each layer inside the core, effectively improving the technical problem that the positive and negative electrode sheets at the middle / inner circle position of the core are prone to wrinkling and deformation, resulting in cyclic voltage drop of the battery and affecting the battery life.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a core support structure, a core structure, and a power battery. Background Art

[0002] For conventional cylindrical power batteries, due to the winding tension and the swelling forces of the positive and negative electrode sheets in the middle / lower part of the core during the middle and later stages of cycling, the positive and negative electrode sheets at the middle / inner part of the core are prone to wrinkling and deformation, resulting in a cyclic drop in battery performance and affecting the battery life.

[0003] In addition, at present, in order to improve the energy density of the battery, the Chuangming Company has proposed the concept of a cylindrical bamboo-vine battery, in which at least two cores are connected end to end through a current collecting structure to form a core group arranged linearly or non-linearly. The core group arranged in this way poses new requirements for structural stability, such as the axial center positioning between linearly arranged cores. Moreover, for the core group arranged in this way, new requirements are put forward for the liquid absorption and backflow of the electrolyte, etc., but there is no special solution in the prior art. Summary of the Invention

[0004] The purpose of the present application is to provide a core support structure, a core structure, and a power battery, which can improve the technical problem that the positive and negative electrode sheets at the middle / inner part of the core are prone to wrinkling and deformation, resulting in a cyclic drop in battery performance and affecting the battery life.

[0005] To achieve the above purpose, the present application provides a core support structure for inserting into the central hole of at least one core. The core support structure includes a support column and an expansion layer provided on the outer side of the support column. The expansion layer is configured to expand and thicken when immersed in the electrolyte to support the core.

[0006] Optionally, the expansion layer is an expansion tape.

[0007] Optionally, the support column is a support tube, and the support tube is provided with a plurality of through holes penetrating inside and outside, and the through holes are used for the free flow of the electrolyte.

[0008] Optionally, an isolation film layer for liquid absorption and backflow is provided on the outer side of the support column, and the expansion layer is provided on the outer side of the isolation film layer.

[0009] Optionally, the core support structure is configured to be inserted into the central holes of at least two cores, and the expansion layer is used to support each of the cores into which the core support structure is inserted.

[0010] Optionally, a non-expansion structure area is formed at the position corresponding to adjacent cores of the core support structure; the support column is a support tube, and the support tube forms a plurality of through holes corresponding to the non-expansion structure area, and the through holes are used for the free flow of the electrolyte.

[0011] Optionally, an isolation film layer is provided on the outer and inner sides of the support tube, and the isolation film layer is used for liquid absorption and reflux. The electrolyte can flow between the isolation film layers covering the outer and inner sides of the through hole respectively through the through hole.

[0012] To achieve the above object, the present application further provides a core structure, including at least one core and the core support structure as described above. The core support structure is inserted into the central hole of the core to support the core inserted therein by using the expansion layer.

[0013] To achieve the above object, the present application further provides a core structure, including at least two cores and the core support structure as described above. The core support structure is inserted into the central holes of at least some of the cores of the core structure to support each of the cores inserted therein by using the expansion layer.

[0014] To achieve the above object, the present application further provides a power battery, including the core structure as described above.

[0015] In the embodiment of the present application, since the core support structure includes a support column and an expansion layer provided on the outer side of the support column, the expansion layer is configured to expand and thicken when immersed in the electrolyte to support the core. Furthermore, by inserting the core support structure into the central hole of the core, when the battery is filled with liquid, the expansion layer on the outer side of the support column will expand and thicken when immersed in the electrolyte, filling the gap between the core and the central hole, and supporting the inner layers of the core, effectively improving the technical problem that the positive and negative electrode sheets at the middle / inner circle position of the core are prone to wrinkling and deformation, resulting in cyclic diving of the battery and affecting the battery life. Description of the Drawings

[0016] Figure 1 It is a three-dimensional structural schematic diagram of the core support structure according to the first embodiment of the present application. In this embodiment, the through holes are continuously arranged along the support tube.

[0017] Figure 2 It is an exploded structural schematic diagram of the core support structure according to the first embodiment of the present application.

[0018] Figure 3 It is a three-dimensional structural schematic diagram of the core support structure according to the second embodiment of the present application. In this embodiment, the through holes are arranged at the positions of the support tube between adjacent cores.

[0019] Figure 4 It is an exploded structural schematic diagram of the core support structure according to the second embodiment of the present application.

[0020] Figure 5 It is a cross-sectional structural schematic diagram of the core support structure according to the third embodiment of the present application. Compared with the first embodiment, an isolation film layer is provided on the outer side of the support tube.

[0021] Figure 6 It is a schematic cross-sectional structure diagram of the core support structure of the fourth embodiment of the present application. Compared with the second embodiment, an isolation film layer is provided on the outer side of the support tube.

[0022] Figure 7 It is a schematic cross-sectional structure diagram of the core support structure of the fifth embodiment of the present application. Compared with the first embodiment, isolation film layers are provided on the outer and inner sides of the support tube.

[0023] Figure 8 It is a schematic cross-sectional structure diagram of the core support structure of the sixth embodiment of the present application. Compared with the second embodiment, isolation film layers are provided on the outer and inner sides of the support tube.

[0024] Figure 9 It is a schematic three-dimensional structure diagram of the core structure of the embodiment of the present application.

[0025] Figure 10 It is a schematic cross-sectional structure diagram of the core structure of the embodiment of the present application.

[0026] Figure 11 It is a schematic three-dimensional structure diagram of the current collector of the embodiment of the present application.

[0027] Figure 12 Schematic exploded view of the power battery of the embodiment of the present application. Detailed implementation manners

[0028] To make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe the specific implementation manners of the present application in detail with reference to the accompanying drawings. Many specific details are set forth in the following description to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0029] Please refer to Figures 1 to 12 , the embodiment of the present application discloses a core support structure for inserting into the central hole 11 of at least one core 1. The core support structure includes a support column 2 and an expansion layer 3 provided on the outer side of the support column 2. The expansion layer 3 is configured to expand and thicken when immersed in the electrolyte to support the core 1.

[0030] Since the core support structure includes the support column 2 and the expansion layer 3 disposed outside the support column 2, the expansion layer 3 is configured to expand and thicken when immersed in the electrolyte to support the core 1. Then, by inserting the core support structure into the central hole 11 of the core 1, when injecting the electrolyte during the subsequent battery assembly, the expansion layer 3 outside the support column 2 will expand and thicken when immersed in the electrolyte, filling the gap between the central hole 11 of the core 1, supporting each layer inside the core 1, and effectively improving the technical problem that the positive and negative electrode sheets at the middle / inner circle position of the core 1 are prone to wrinkling and deformation, resulting in cyclic voltage drop of the battery and affecting the battery life.

[0031] In some embodiments, the expansion layer 3 is an expansion tape wound around the support column 2. Of course, the expansion layer 3 is not limited to the form of an expansion tape, as long as it can play the role of expanding and thickening when immersed in the electrolyte to support the core 1.

[0032] Specifically, the expansion tape may include an expansion structure layer and an adhesive layer. The expansion tape is adhered to the support column 2 through the adhesive layer, and the expansion structure layer may be made of a modified resin material with an expansion effect, but is not limited thereto.

[0033] Specifically, the expansion layer 3 is not limited to being continuous in the extending direction of the support column 2. For example, in the examples shown in the respective figures, the expansion layer 3 is provided in segments on the support column 2. In these examples, each segment of the expansion layer 3 is respectively inserted into the central hole 11 of different cores 1. Of course, the part of the expansion layer 3 corresponding to one core 1 is not limited to being continuous either. In short, the expansion layer 3 can play the role of expanding and thickening when immersed in the electrolyte to support the core 1.

[0034] In some embodiments, the support column 2 is a support tube 2, but is not limited thereto. Specifically, the support tube 2 may be made of stainless steel, but is not limited thereto.

[0035] Specifically, the support tube 2 is provided with a plurality of through holes 21 (preferably micro holes) penetrating through the inside and outside, and the through holes 21 are used to allow the electrolyte to flow freely. By providing the plurality of through holes 21 on the support tube 2, when injecting the electrolyte during the subsequent battery injection (such as injecting through the injection hole facing the central hole 11 of the core 1), the through holes 21 allow the electrolyte to flow freely, which is conducive to rapid and sufficient injection.

[0036] In Figure 1 、 Figure 5 and Figure 7 In the specific examples shown, the through holes 21 are continuously distributed along the extending direction of the support tube 2, that is, the through holes 21 are continuously provided from one end of the support tube 2 to the other end. Of course, it is not limited thereto. For example, in Figure 3 and Figure 4 In the specific examples shown, the through holes 21 are only provided in a certain area of the support tube 2.

[0037] In each of the examples shown in the drawings, the through holes 21 are evenly distributed circumferentially along the support tube 2, but are not limited thereto.

[0038] In summary, the present application does not limit the setting position of the through holes 21, as long as it can play a role in enabling the electrolyte to flow freely.

[0039] In addition, the specific form of the through holes 21 is not limited either.

[0040] Please refer to Figures 5 to 8 , in some embodiments, an isolation membrane layer 4 for liquid absorption and reflux is provided on the outer side of the support column 2, and the expansion layer 3 is provided on the outer side of the isolation membrane layer 4. Since the isolation membrane layer 4 is provided on the outer side of the support column 2, it is convenient for the electrolyte to be absorbed and refluxed to infiltrate the core 1 on its outer side.

[0041] Specifically, the isolation membrane layer 4 is arranged on the support column 2 by winding, and can be wound at least one turn. Of course, the isolation membrane layer 4 is not limited to being arranged on the support column 2 by winding.

[0042] Specifically, the material of the isolation membrane layer 4 is not limited, and it can adopt materials used in the industry, such as PP, PE materials, etc., as long as it can play a role in liquid absorption and reflux.

[0043] Please refer to Figure 7 and Figure 8 , specifically, when the support column 2 is the support tube 2, an isolation membrane layer 5 for liquid absorption and reflux can also be provided on the inner side of the support tube 2.

[0044] More specifically, when the isolation membrane layers 4 / 5 are provided on both the inner and outer sides of the support tube 2, a plurality of through holes 21 penetrating through the inside and outside can be provided on the support tube 2, and the electrolyte can flow between the isolation membrane layers 4 / 5 covering the outer side and the inner side of the through holes 21 respectively through the through holes 21, which is more conducive to the rapid reflux (back suction) of the electrolyte.

[0045] In some embodiments, the core support structure is configured to be inserted into the central holes 11 of at least two cores 1, and the expansion layer 3 is used to support each core 1 into which the core support structure is inserted. Since the core support structure is configured to be inserted into the central holes 11 of at least two cores 1, its expansion layer 3 can support each core 1 into which it is inserted, which is conducive to the positioning of each core 1. For example, when the cores 1 are arranged in a straight line, at this time the support columns 2 extend linearly. By means of the support of the expansion layer 3 for each core 1, it is conducive to the axial positioning of each core 1. Of course, the cores 1 are not limited to being arranged in a straight line, and they can also be arranged in a non-straight line. For example, the first and the second of the three cores 1 are arranged in a straight line, and the third is inclined at a certain angle relative to the second. At this time, the extending direction of the support column 2 can be adapted to the arrangement direction of the cores 1. Therefore, when the support column 2 is inserted into each core 1, by means of the support of the expansion layer 3 for each core 1, it is conducive to the positioning of each core 1.

[0046] Please refer to Figure 3 and Figure 4 , specifically, the support column 2 forms a non-expansion structure area 22 at the position between adjacent cores 1 (i.e., the position corresponding to the interval area between the cores 1). The support column 2 is a support tube 2, and the support tube 2 forms a plurality of through holes 21 corresponding to the non-expansion structure area 22. The through holes 21 are used for the free flow of the electrolyte. Since the support tube 2 is provided with a plurality of through holes 21 in the non-expansion structure area 22 between adjacent cores 1, when the battery is filled with liquid, the electrolyte can be more concentratedly delivered to the end of the core 1, which is more likely to promote the liquid seepage from the end of the core 1.

[0047] Please refer to Figure 8 , more specifically, isolation film layers 4 / 5 are provided on the outer and inner sides of the support tube 2. The isolation film layers 4 / 5 are used for liquid absorption and reflux. Due to the setting of the isolation film layers 4 / 5, it is convenient for the absorption and reflux of the electrolyte. Since the isolation film layers 4 / 5 are provided on both the outer and inner sides of the support tube 2, and a plurality of through holes 21 are formed on the support tube 2, the electrolyte can flow between the isolation film layers 4 / 5 covering the outer and inner sides of the through holes 21 respectively through the through holes 21, which is more conducive to the rapid reflux of the electrolyte.

[0048] Please combine Figures 1 to 11 , the present application also discloses a core structure, including at least one core 1 and the core support structure as described above. The core support structure is inserted into the central hole 11 of the core 1 to support the core 1 into which it is inserted by using the expansion layer 3. Here, "the core support structure is inserted into the central hole 11 of the core 1" can be inserted into the central holes 11 of all the cores 1 of the core structure, or can be inserted into the central holes 11 of some cores 1 (when the core structure has at least two cores 1).

[0049] In this application, the core support structure is inserted into the central hole 11 of at least part of the core 1 of the core structure to support each core 1 where it is inserted by means of the expansion layer 3. When the battery is filled with electrolyte subsequently, the expansion layer 3 outside the support column 2 will expand and thicken when immersed in the electrolyte, filling the gap between it and the central hole 11 of the core 1, supporting each layer inside the core 1, and effectively improving the technical problem that the positive and negative electrode sheets at the middle / inner circle position of the core 1 are prone to wrinkling and deformation, resulting in cyclic voltage drop of the battery and affecting the battery life.

[0050] When the core support structure is inserted into the central holes 11 of at least two cores 1, when the expansion layer 3 expands and thickens when immersed in the electrolyte, it can support each inserted core 1, and thus is beneficial to the positioning between the cores 1 while supporting each core 1.

[0051] In some embodiments, when the core structure has at least two cores 1, full tabs are formed at the ends of each core 1, and the full tabs of adjacent cores 1 are spaced apart and connected by a current collector 6. The current collector 6 can be a single-piece structure or composed of at least two structural members, which is not limited here. In a specific example, the current collector 6 is bent from a sheet into a U shape, and through holes 61 corresponding to the central holes 11 of the cores 1 and for the core support structure to pass through are formed thereon.

[0052] Please refer to Figures 1 to 12 , this application also discloses a power battery including the core structure as described above.

[0053] In some embodiments, the core structure includes at least two cores 1, and each core 1 is linearly arranged. The power battery further includes a housing 7 sleeved outside each core 1, and a top cover (not shown in the figure) is assembled at the open end of the housing 7. A liquid injection hole can be provided on the top cover, and the liquid injection hole can be directly opposite to the central hole 11 of the core 1.

[0054] The above-disclosed are only the preferred examples of this application, which are used to facilitate the understanding of those skilled in the art and implement accordingly. Of course, the scope of rights of this application cannot be limited thereby. Therefore, equivalent changes made according to the scope of the patent application of this application still fall within the scope covered by this application.

Claims

1. A winding core support structure, used for inserting into the central hole of at least one winding core, characterized in that: The winding core support structure includes a support column and an expansion layer disposed outside the support column, wherein the expansion layer is configured to expand and become thicker when immersed in an electrolyte to support the winding core; The support column is a support tube, and the support tube is provided with a plurality of through holes penetrating inside and outside, and the through holes are used to allow the electrolyte to flow freely; The support tube is provided with an isolation film layer on the outside and inside, and the isolation film layer is used for absorbing liquid and refluxing. The expansion layer is arranged on the outside of the isolation film layer on the outside of the support tube, and the electrolyte can flow between the isolation film layers respectively covering the outside and inside of the through hole through the through hole.

2. The winding core support structure according to claim 1, characterized in that: The expansion layer is an expansion tape.

3. The winding core support structure according to claim 1, characterized in that: The core support structure is configured to be inserted into the central holes of at least two of the cores, and the expansion layer is used to support each of the cores inserted into the core support structure.

4. The winding core support structure according to claim 3, characterized in that: The core support structure forms a non-expanded structure area at positions corresponding to adjacent cores; The support tube forms a plurality of through holes corresponding to the non-expanded structure area.

5. A winding core structure, characterized in that: The invention comprises at least one winding core and the winding core supporting structure as claimed in claim 1 or 2, wherein the winding core supporting structure is inserted into the central hole of the winding core to support the winding core inserted therein by using the expansion layer.

6. A winding core structure, characterized in that: It comprises at least two winding cores and a winding core supporting structure as claimed in claim 3 or 4, wherein the winding core supporting structure is inserted into the central hole of at least part of the winding cores of the winding core structure to support each of the winding cores inserted therein by utilizing the expansion layer.

7. A power battery, characterized in that: Comprising the winding core structure as claimed in claim 5 or 6.

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