Roll core supporting rod structure, power battery and assembly method of power battery

Abstract

The invention discloses a roll core supporting rod structure, a power battery and an assembly method of the power battery, the roll core supporting rod structure comprises a first supporting rod and a second supporting rod, a first binding surface of the first supporting rod is recessed along at least one area in the length direction to form a first concave surface, and by means of the formation of the first concave surface, the first binding surface of the first supporting rod is attached to the second supporting rod. The first binding surface forms a first convex surface, the first concave surface and the first convex surface are in smooth connection, the second binding surface of the second supporting rod is recessed in at least one area in the length direction of the second binding surface to form a second concave surface, the second binding surface forms a second convex surface by means of the formation of the second concave surface, and the second concave surface and the second convex surface are in smooth connection. When the first supporting rod and the second supporting rod are inserted into the center hole, the first supporting rod and the second supporting rod are staggered and combined in the length direction, the first convex face and the second concave face are attached, the first concave face and the second convex face are attached, and after the first supporting rod and the second supporting rod are inserted in place, the first convex face and the second convex face are attached.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a winding core support rod structure, a power battery, and an assembly method for a power battery. Background Art

[0002] At present, cylindrical power batteries such as lithium-ion and sodium-ion have gradually become mainstream products in the new energy industry due to their high energy density, good capacity consistency, and ability to support high-rate charge and discharge. With the popularization of new energy vehicles, people have put forward higher and higher requirements for the long life of power batteries. However, cylindrical power batteries currently have the following common problems:

[0003] Due to the winding tension and the expansion force of the positive and negative electrodes in the middle and late stages of the cycle, conventional cylindrical power batteries are prone to wrinkling and deformation in the radial middle / inner circle of the winding core and the positive and negative electrodes in the middle of the length, causing the battery to experience a cycle dive and affecting the battery life.

[0004] Most manufacturers insert the support rod directly into the center hole of the core after winding. To facilitate insertion, the support rod must be thinner than the diameter of the center hole, which results in the support rod being unable to effectively improve the wrinkle deformation problem of the positive and negative electrode sheets. Summary of the invention

[0005] The purpose of the present application is to provide a winding core support rod structure, a power battery and a power battery assembly method, which can solve at least one technical problem in the above-mentioned background technology.

[0006] To achieve the above-mentioned objectives, the present application provides a core support rod structure for inserting into the center hole of a cylindrical core to support the core, the core support rod structure comprising a first support rod and a second support rod, after being assembled in the center hole of the core, the first support rod and the second support rod are configured to be laterally bonded together to support the core, the first support rod comprising a first bonding surface and a first supporting side surface, the second support rod comprising a second bonding surface and a second supporting side surface, the first support rod and the second support rod are laterally bonded by the first bonding surface and the second bonding surface and the core is laterally supported by the first supporting side surface and the second supporting side surface, and the first bonding surface is recessed in at least one area along its length direction to form a first concave surface , by forming the first concave surface, the first fitting surface forms a first convex surface, the first concave surface and the first convex surface are smoothly connected, the second fitting surface is recessed to form a second concave surface in at least one area along its length direction, by forming the second concave surface, the second fitting surface forms a second convex surface, the second concave surface and the second convex surface are smoothly connected, when inserted into the center hole, the first support rod and the second support rod are staggered and combined in the length direction, the first convex surface and the second concave surface are fitted, the first concave surface and the second convex surface are fitted, by relative sliding of the first support rod and the second support rod, after the first support rod and the second support rod are inserted into place, the first convex surface and the second convex surface are fitted.

[0007] Optionally, the first support rod is formed with the first concave surface and the first convex surface alternating in the length direction; and the second support rod is formed with the second concave surface and the second convex surface alternating in the length direction.

[0008] Optionally, the first support rod includes three first convex surfaces respectively located in the middle and at both ends and two first concave surfaces located between the first convex surfaces; the second support rod includes three second convex surfaces respectively located in the middle and at both ends and two second concave surfaces located between the second convex surfaces; after the first support rod and the second support rod are inserted into place, the three first convex surfaces and the three second convex surfaces fit in one-to-one correspondence.

[0009] Optionally, a guide groove extending along its length direction is formed on the first support rod, and the guide groove is open toward one side of the first concave surface and the first convex surface; the second support rod is provided with a guide protrusion extending along its length direction on the side where the second concave surface and the second convex surface are located, and the guide protrusion can be slidably arranged in the guide groove along the length direction.

[0010] Optionally, the first support rod is formed with a plurality of first penetration holes penetrating laterally to connect the guide groove with the outside.

[0011] Optionally, the second support rod is formed with a liquid injection through hole penetrating along the length direction thereof, and the second support rod is formed with a plurality of second penetration holes penetrating laterally to connect the liquid injection through hole with the outside.

[0012] Optionally, after the first support rod and the second support rod are inserted into place, the first convex surface and the second convex surface fit together so that the winding core support rod structure is cylindrical as a whole.

[0013] Optionally, at a position corresponding to the first convex surface, the first supporting side surface is semi-cylindrical, and the first supporting side surface is cut off at least at a position connected to the first convex surface to form a first cross-section; at a position corresponding to the second convex surface, the second supporting side surface is semi-cylindrical, and the first supporting side surface is cut off at least at a position connected to the second convex surface to form a second cross-section.

[0014] To achieve the above objectives, the present application also provides a power battery, including a shell, a winding core and a winding core support rod structure as described above, wherein the winding core is sleeved in the shell, and the winding core support rod structure is inserted into the center hole of the winding core.

[0015] To achieve the above objectives, the present application also provides a method for assembling a power battery, comprising:

[0016] Staggering and combining the first supporting rod and the second supporting rod in the length direction so that the first convex surface fits with the second concave surface, and the first concave surface fits with the second convex surface;

[0017] Inserting the staggered first support rod and the second support rod into the central hole, wherein one of the first support rod and the second support rod touches the bottom of the shell;

[0018] Apply force to the other one of the first support rod and the second support rod to make it slide toward the shell bottom relative to one of the first support rod and the second support rod until it touches the shell bottom, the first convex surface and the second convex surface are in contact, and the first supporting side surface and the second supporting side surface provide lateral support for each layer structure of the core.

[0019] In the embodiment of the present application, the first fitting surface of the first support rod is recessed to form a first concave surface and a first convex surface distributed in the length direction, and the first concave surface and the first convex surface are smoothly connected. The second fitting surface of the second support rod is recessed to form a second concave surface and a second convex surface distributed in the length direction, and the second concave surface and the second convex surface are smoothly connected. When inserted into the center hole of the winding core, the first support rod and the second support rod are staggered and combined in the length direction, and the first convex surface and the second concave surface are fitted together, and the first concave surface and the second convex surface are fitted together, so that the size of the winding core support rod structure in this state is smaller, and it is easier to insert into the center hole, by the relative sliding of the first support rod and the second support rod. After the first support rod and the second support rod are inserted into place, the first convex surface and the second convex surface fit together to increase the size of the core support rod structure to further fill the gap between the core support rod structure and the center hole when the first support rod and the second support rod are staggered and combined, and then the first support side surface and the second support side surface can jointly support the various layers of the core structure, which not only avoids the problem of difficulty in inserting the core support rod structure into the center hole after winding, but also realizes the effective support of the core support rod structure to the core, offsets the winding tension of the middle / inner circle position of the core (positive / negative electrode sheets) and the expansion force of the positive and negative electrode sheets in the middle and late stages of the cycle, and improves the structural stability and cycle life of the power battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure when the core support rod structure of the embodiment of the present application is in a staggered and fitted state.

[0021] Figure 2 It is a schematic diagram of the three-dimensional structure when the core support rod structure of the embodiment of the present application is in a normal supporting state.

[0022] Figure 3 yes Figure 1 Schematic diagram of the cross-sectional structure of the middle roll core support rod structure.

[0023] Figure 4 yes Figure 2 Schematic diagram of the cross-sectional structure of the middle roll core support rod structure.

[0024] Figure 5 It is a schematic diagram of the three-dimensional structure of the first support rod in the embodiment of the present application.

[0025] Figure 6 It is another three-dimensional structural schematic diagram of the first support rod of the embodiment of the present application.

[0026] Figure 7 It is a schematic diagram of the three-dimensional structure of the second support rod in the embodiment of the present application.

[0027] Figure 8 It is another three-dimensional structural schematic diagram of the second support rod in the embodiment of the present application.

[0028] Fig. 9 It is a schematic diagram of the three-dimensional structure of the winding core and the winding core support rod structure of an embodiment of the present application, wherein the first support rod and the second support rod are staggered and fitted.

[0029] Fig.10 It is a schematic diagram of the three-dimensional structure of the winding core and the winding core support rod structure of an embodiment of the present application, wherein the first support rod and the second support rod are both plugged into place. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of 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 violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0031] See also Figures 1 to 10 The embodiment of the present application discloses a core support rod structure, which is used to insert into the center hole 11 of a cylindrical core 10 to support the core 10. The core support rod structure includes a first support rod 20 and a second support rod 30. After being assembled in the center hole 11 of the core 10, the first support rod 20 and the second support rod 30 are configured to be laterally bonded together to support the core 10. The first support rod 20 includes a first bonding surface 21 and a first supporting side surface 22. The second support rod 30 includes a second bonding surface 31 and a second supporting side surface 32. The first support rod 20 and the second support rod 30 are laterally bonded through the first bonding surface 21 and the second bonding surface 31, and the core 10 is laterally supported through the first supporting side surface 22 and the second supporting side surface 32. The first bonding surface 21 is recessed in at least one area along its length direction to form a first concave surface 23. By forming the first concave surface 23, the first The fitting surface 21 forms a first convex surface 24, and the first concave surface 23 and the first convex surface 24 are smoothly connected. The second fitting surface 31 is recessed in at least one area along its length direction to form a second concave surface 33. By forming the second concave surface 33, the second fitting surface 31 forms a second convex surface 34, and the second concave surface 33 and the second convex surface 34 are smoothly connected. When inserted into the center hole 11, the first support rod 20 and the second support rod 30 are staggered and combined in the length direction, and the first convex surface 24 and the second concave surface 33 are fitted together, and the first concave surface 23 and the second convex surface 34 are fitted together. By relative sliding of the first support rod 20 and the second support rod 30, after the first support rod 20 and the second support rod 30 are inserted into place, the first convex surface 24 and the second convex surface 34 are fitted together.

[0032] In the embodiment of the present application, the first fitting surface 21 of the first support rod 20 is recessed to form a first concave surface 23 and a first convex surface 24 distributed in the length direction, and the first concave surface 23 and the first convex surface 24 are smoothly connected. The second fitting surface 31 of the second support rod 30 is recessed to form a second concave surface 33 and a second convex surface 34 distributed in the length direction, and the second concave surface 33 and the second convex surface 34 are smoothly connected. When inserted into the center hole 11 of the winding core 10, the first support rod 20 and the second support rod 30 are staggered and combined in the length direction, and the first convex surface 24 and the second concave surface 33 are fitted together, and the first concave surface 23 and the second convex surface 34 are fitted together, so that the size of the winding core support rod structure in this state is smaller, and it is easier to insert into the center hole 11, and the first support rod 20 and the second The relative sliding of the support rod 30, after the first support rod 20 and the second support rod 30 are inserted into place, the first convex surface 24 and the second convex surface 34 fit together to increase the size of the core support rod structure to further fill the gap between the core support rod structure and the center hole 11 when the first support rod 20 and the second support rod 30 are staggered and combined, and then the first support side surface 22 and the second support side surface 32 can jointly support the various layers of the core 10, which not only avoids the problem of difficulty in inserting the core support rod structure into the center hole 11 after winding, but also realizes the effective support of the core support rod structure to the core 10, offsets the winding tension of the middle / inner circle position (positive / negative electrode sheets) of the core 10 and the expansion force of the positive and negative electrode sheets in the middle and late stages of the cycle, and improves the structural stability and cycle life of the power battery.

[0033] Since the first concave surface 23 and the first convex surface 24 are smoothly connected, and the second concave surface 33 and the second convex surface 34 are smoothly connected, it is convenient for the first convex surface 24 to slide relatively between the second concave surface 33 and the second convex surface 34, and the second convex surface 34 to slide relatively between the first concave surface 23 and the first convex surface 24. Specifically, the first concave surface 23 and the first convex surface 24, and the second concave surface 33 and the second convex surface 34 are smoothly connected by the inclined surface X.

[0034] In some embodiments, the first support rod 20 is formed with first concave surfaces 23 and first convex surfaces 24 alternating in the length direction, and adjacent first concave surfaces 23 and first convex surfaces 24 are smoothly connected to facilitate sliding; the second support rod 30 is formed with second concave surfaces 33 and second convex surfaces 34 alternating in the length direction, and adjacent second concave surfaces 33 and second convex surfaces 34 are smoothly connected to facilitate sliding.

[0035] Specifically, the first support rod 20 includes three first convex surfaces 24 respectively located in the middle and at both ends and two first concave surfaces 23 located between the first convex surfaces 24; the second support rod 30 includes three second convex surfaces 34 respectively located in the middle and at both ends and two second concave surfaces 33 located between the second convex surfaces 34; after the first support rod 20 and the second support rod 30 are inserted into place, the three first convex surfaces 24 and the three second convex surfaces 34 fit in one by one.

[0036] In a specific example, the first convex surface 24 at both ends is shorter, the first convex surface 24 at the middle is longer, and the lengths of the two first concave surfaces 23 are equivalent to the length of the first convex surface 24 at the middle. The second convex surfaces 34 at both ends are shorter, the second convex surface 34 at the middle is longer, and the lengths of the two second concave surfaces 33 are equivalent to the length of the second convex surface 34 at the middle. Of course, this is not limited to this.

[0037] In some embodiments, the first support rod 20 is formed with a guide groove 25 extending along its length direction, and the guide groove 25 is open toward one side of the first concave surface 23 and the first convex surface 24; the second support rod 30 is convexly provided with a guide protrusion 35 extending along its length direction on the side where the second concave surface 33 and the second convex surface 34 are located, and the guide protrusion 35 can be slidably arranged in the guide groove 25 along the length direction. By the cooperation of the guide groove 25 and the guide protrusion 35, the relative sliding of the first support rod 20 and the second support rod 30 can be guided.

[0038] Specifically, a plurality of first penetration holes 26 are formed on the first support rod 20 to penetrate laterally and connect the guide groove 25 with the outside. By providing the first penetration holes 26, the electrolyte inside and outside the first support rod 20 can flow freely through the first penetration holes 26.

[0039] Furthermore, the first permeable holes 26 are distributed along the length direction of the first support rod 20 .

[0040] In some embodiments, the second support rod 30 is formed with a liquid injection through hole 36 penetrating along the length direction thereof, and the second support rod 30 is formed with a plurality of second penetration holes 37 penetrating laterally to connect the liquid injection through hole 36 and the outside. By providing the liquid injection through hole 36, liquid can be injected into the liquid injection through hole 36, and by providing the second penetration holes 37, the electrolyte inside and outside the second support rod 30 can flow freely through the second penetration holes 37.

[0041] Specifically, the first penetration holes 26 are distributed along the length direction of the second support rod 30 .

[0042] In some embodiments, after the first support rod 20 and the second support rod 30 are inserted into place, the first convex surface 24 and the second convex surface 34 fit together so that the winding core support rod structure is cylindrical as a whole. That is, the first support side surface 22 and the second support side surface 32 are respectively parts of the same cylindrical surface. It should be noted that being cylindrical as a whole does not mean being strictly cylindrical. For example, in a specific example, a section surface may also be formed on the cylindrical surface.

[0043] Specifically, at the position corresponding to the first convex surface 24, the first supporting side surface 22 is in the shape of a semi-cylindrical surface as a whole, and the first supporting side surface 22 is cut off at least at the position connected to the first convex surface 24 to form a first cut surface 28; at the position corresponding to the second convex surface 34, the second supporting side surface 32 is in the shape of a semi-cylindrical surface as a whole, and the first supporting side surface 22 is cut off at least at the position connected to the second convex surface 34 to form a second cut surface 38. Due to the formation of the first cut surface 28 and the second cut surface 38, the first support rod 20 and the second support rod 30 can also be smoothly inserted into the center hole 11 in the lateral direction defined by the cut surface, and at the same time, due to the limited width of the cut surface, the support of the winding core 10 is basically not affected.

[0044] In a specific example, along the length direction of the first support rod 20, both sides of the first support rod 20 respectively form a continuous whole first section 28. Along the length direction of the second support rod 30, both sides of the second support rod 30 respectively form a continuous whole second section 38.

[0045] In a specific example, the first support rod 20 and the second support rod 30 are staggered, that is, the size d when the concave and convex are attached is smaller than the diameter D when the convex and convex are attached. Due to the formation of the section, the size W remains fixed smaller than the diameter D, specifically, W=D-(0.1-0.5).

[0046] In some embodiments, in order to facilitate insertion into the central hole 11 , at least one end of the first support rod 20 is formed with a tapered guide surface 29 , and at least one end of the second support rod 30 is formed with a tapered guide surface 39 .

[0047] In some embodiments, the material of the first support rod 20 and the second support rod 30 can be PP injection molding, or ceramic, etc., without specific limitation.

[0048] See also Figures 1 to 10 The embodiment of the present application also discloses a power battery, including a shell (not shown), a core 10 and the core support rod structure as described above, the core 10 is sleeved in the shell, and the core support rod structure is inserted into the center hole 11 of the core 10.

[0049] In the embodiment of the present application, when the center hole 11 of the winding core 10 is inserted, the first support rod 20 and the second support rod 30 are staggered and combined in the length direction, the first convex surface 24 and the second concave surface 33 are fitted, and the first concave surface 23 and the second convex surface 34 are fitted, so that the size of the winding core support rod structure in this state is smaller, and it is easier to insert into the center hole 11. By the relative sliding of the first support rod 20 and the second support rod 30, after the first support rod 20 and the second support rod 30 are inserted into place, the first convex surface 24 and the second convex surface 34 are fitted so that the size of the winding core support rod structure The size becomes larger to further fill the gap between the core support rod structure and the center hole 11 when the first support rod 20 and the second support rod 30 are staggered and combined, and then the first support side surface 22 and the second support side surface 32 can jointly support the various layers of the core 10, which not only avoids the problem of difficulty in inserting the core support rod structure into the center hole 11 after winding, but also realizes the effective support of the core support rod structure to the core 10, offsets the winding tension of the middle / inner circle position (positive / negative electrode sheet) of the core 10 and the expansion force of the positive and negative electrode sheets in the middle and late stages of the cycle, and improves the structural stability and cycle life of the power battery.

[0050] The present application also discloses a method for assembling the power battery as described above, comprising:

[0051] The first support rod 20 and the second support rod 30 are staggered and combined in the length direction, so that the first convex surface 24 and the second concave surface 33 are in contact with each other, and the first concave surface 23 and the second convex surface 34 are in contact with each other;

[0052] Insert the staggered first support rod 20 and the second support rod 30 into the central hole 11, and one of the first support rod 20 and the second support rod 30 touches the bottom of the shell;

[0053] Apply force to the other one of the first support rod 20 and the second support rod 30 to make it slide toward the bottom of the shell relative to one of the first support rod 20 and the second support rod 30 until it touches the bottom of the shell, and the first convex surface 24 and the second convex surface 34 fit together (when the first support rod 20 and the second support rod 30 are both inserted into place), and the first support side surface 22 and the second support side surface 32 provide lateral support for each layer structure of the winding core 10.

[0054] In a specific embodiment, when the first support rod 20 and the second support rod 30 are accurately inserted into the center hole 11, Fig. 9 When both are inserted into place, the second support rod 30 and the second support rod 30 are in a state of being staggered and fitted. Fig.10 shown.

[0055] The above disclosure is only a preferred example of the present application, and its role is to facilitate the technical personnel in this field to understand and implement it. Of course, it cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the scope of the patent application of the present application still fall within the scope covered by the present application.

Claims

1. A core support rod structure, used to insert into the center hole of a cylindrical core to support the core, characterized in that: The core support rod structure includes a first support rod and a second support rod, and after being assembled in the center hole of the core, the first support rod and the second support rod are configured to be laterally bonded together to support the core, the first support rod includes a first bonding surface and a first supporting side surface, the second support rod includes a second bonding surface and a second supporting side surface, the first support rod and the second support rod are laterally bonded through the first bonding surface and the second bonding surface, and the core is laterally supported by the first supporting side surface and the second supporting side surface, the first bonding surface is recessed to form a first concave surface in at least one area along its length direction, and by forming the first concave surface, the first bonding surface is shaped The first convex surface is formed, the first concave surface and the first convex surface are smoothly connected, the second fitting surface is recessed to form a second concave surface in at least one area along its length direction, and through the formation of the second concave surface, the second fitting surface forms a second convex surface, and the second concave surface and the second convex surface are smoothly connected. When inserted into the center hole, the first support rod and the second support rod are staggered and combined in the length direction, the first convex surface and the second concave surface are fitted together, and the first concave surface and the second convex surface are fitted together. Through the relative sliding of the first support rod and the second support rod, after the first support rod and the second support rod are inserted into place, the first convex surface and the second convex surface are fitted together.

2. The winding core support rod structure according to claim 1, characterized in that: The first supporting rod is formed with the first concave surface and the first convex surface alternating in the length direction; the second supporting rod is formed with the second concave surface and the second convex surface alternating in the length direction.

3. The winding core support rod structure according to claim 2, characterized in that: The first support rod includes three first convex surfaces respectively located in the middle and at both ends and two first concave surfaces located between the first convex surfaces; the second support rod includes three second convex surfaces respectively located in the middle and at both ends and two second concave surfaces located between the second convex surfaces; after the first support rod and the second support rod are inserted into place, the three first convex surfaces and the three second convex surfaces are fitted one by one.

4. The winding core support rod structure according to claim 1, characterized in that: The first support rod is provided with a guide groove extending along its length direction, and the guide groove is open toward one side of the first concave surface and the first convex surface; the second support rod is provided with a guide protrusion extending along its length direction on the side where the second concave surface and the second convex surface are located, and the guide protrusion can be slidably arranged in the guide groove along the length direction.

5. The winding core support rod structure according to claim 4, characterized in that: The first support rod is formed with a plurality of first penetration holes which penetrate laterally to connect the guide groove with the outside.

6. The winding core support rod structure according to claim 1, characterized in that: The second support rod is formed with a liquid injection through hole penetrating along the length direction thereof, and the second support rod is formed with a plurality of second penetration holes penetrating laterally to connect the liquid injection through hole with the outside.

7. The winding core support rod structure according to claim 1, characterized in that: After the first support rod and the second support rod are inserted into place, the first convex surface and the second convex surface fit together so that the winding core support rod structure is cylindrical as a whole.

8. The winding core support rod structure according to claim 7, characterized in that: At a position corresponding to the first convex surface, the first supporting side surface is semi-cylindrical, and the first supporting side surface is cut off at least at a position connected to the first convex surface to form a first cross-section; at a position corresponding to the second convex surface, the second supporting side surface is semi-cylindrical, and the first supporting side surface is cut off at least at a position connected to the second convex surface to form a second cross-section.

9. A power battery, characterized in that: The invention comprises a shell, a winding core and a winding core support rod structure as claimed in any one of claims 1 to 8, wherein the winding core is sleeved in the shell, and the winding core support rod structure is inserted into the central hole of the winding core.

10. The method for assembling a power battery according to claim 9, characterized in that: include: Staggering and combining the first supporting rod and the second supporting rod in the length direction so that the first convex surface fits with the second concave surface, and the first concave surface fits with the second convex surface; Inserting the staggered first support rod and the second support rod into the central hole, wherein one of the first support rod and the second support rod touches the bottom of the shell; Apply force to the other one of the first support rod and the second support rod to make it slide toward the shell bottom relative to one of the first support rod and the second support rod until it touches the shell bottom, the first convex surface and the second convex surface are in contact, and the first supporting side surface and the second supporting side surface provide lateral support for each layer structure of the core.

Images