Core support rod structure, power battery and power battery assembly method

Abstract

This application discloses a core support rod structure, a power battery, and a method for assembling the power battery. The core support rod structure includes a first support rod and a second support rod. The first contact surface of the first support rod has a first concave surface formed in at least one region along its length direction. By forming the first concave surface, the first contact surface forms a first convex surface. The first concave surface and the first convex surface are smoothly connected. The second contact surface of the second support rod has a second concave surface formed in at least one region along its length direction. By forming the second concave surface, the second contact surface forms a second convex surface. The second concave surface and the second convex surface are smoothly connected. When inserted into a central hole, the first support rod and the second support rod are staggered in the length direction, and the first convex surface and the second concave surface are in contact. The first concave surface and the second convex surface are in contact. After both the first support rod and the second support rod are inserted into place, the first convex surface and the second convex surface are in contact.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a core support rod structure, a power battery, and a method for assembling the power battery. Background Technology

[0002] Currently, cylindrical power batteries such as lithium-ion and sodium-ion batteries are gradually becoming mainstream products in the new energy industry due to their high energy density, good capacity consistency, and ability to support high-rate charging and discharging. With the increasing popularity of new energy vehicles, people are placing increasingly higher demands on the long lifespan of power batteries. However, cylindrical power batteries currently suffer from the following common problems:

[0003] Due to the winding tension and the expansion force of the positive and negative electrode plates in the later stages of cycling, the positive and negative electrode plates in the radial / inner circle and the middle of the length of the core of conventional cylindrical power batteries are prone to wrinkling and deformation, which can lead to battery cycle drops and affect battery life.

[0004] Most manufacturers insert a support rod directly into the center hole of the core after it is wound. To facilitate insertion, the support rod must be slightly smaller than the diameter of the center hole, which makes it impossible for the support rod to effectively improve the wrinkling and deformation of the positive and negative electrode sheets. Summary of the Invention

[0005] The purpose of this application is to provide a core support rod structure, a power battery, and a method for assembling the power battery, which can solve at least one of the technical problems in the background art.

[0006] To achieve the above objectives, this 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 includes a first support rod and a second support rod. After being assembled into the center hole of the core, the first and second support rods are configured to be laterally fitted together to support the core. The first support rod includes a first contact surface and a first support side surface, and the second support rod includes a second contact surface and a second support side surface. The first and second support rods are laterally fitted together through the first and second contact surfaces and laterally support the core through the first and second support side surfaces. At least one region of the first contact surface along its length is recessed to form a first concave surface. By forming the first concave surface, the first mating surface forms a first convex surface, and the first concave surface and the first convex surface are smoothly connected. The second mating surface has a second concave surface formed in at least one region along its length direction. By forming the second concave surface, the second mating surface forms a second convex surface, and the second concave surface and the second convex surface are smoothly connected. When the central hole is inserted, the first support rod and the second support rod are staggered in the length direction. The first convex surface and the second concave surface are mated, and the first concave surface and the second convex surface are mated. 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 both inserted into place, the first convex surface and the second convex surface are mated.

[0007] Optionally, the first support rod has alternating first concave surfaces and first convex surfaces in the length direction; the second support rod has alternating second concave surfaces and second convex surfaces in the length direction.

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

[0009] Optionally, the first support rod has a guide groove extending along its length, the guide groove being open to one side facing the first concave surface and the first convex surface; the second support rod has a guide protrusion extending along its length on one side where the second concave surface and the second convex surface are located, the guide protrusion being slidably disposed in the guide groove along its length.

[0010] Optionally, the first support rod has a plurality of first permeation holes that extend laterally through to connect the guide groove and the outside.

[0011] Optionally, the second support rod has an injection through hole extending along its length, and the second support rod has a plurality of second permeation holes extending laterally to connect the injection through hole with the outside.

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

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

[0014] To achieve the above objectives, this application also provides a power battery, including a housing, a core, and a core support rod structure as described above, wherein the core is sleeved inside the housing, and the core support rod structure is inserted into the central hole of the core.

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

[0016] The first support rod and the second support rod are staggered in the length direction so that the first convex surface and the second concave surface are in contact, and the first concave surface and the second convex surface are in contact.

[0017] The first and second support rods, which are staggered and joined together, are inserted into the central hole, with one of the first and second support rods touching the bottom of the housing.

[0018] Force is applied to the other of the first and second support rods, causing it to slide relative to the first and second support rods toward the bottom of the shell until it touches the bottom of the shell. The first convex surface and the second convex surface are in contact, and the first support side and the second support side provide lateral support to each layer of the core structure.

[0019] In this embodiment, the first contact surface of the first support rod is formed by a first concave surface and a first convex surface distributed along the length direction, and the first concave surface and the first convex surface are smoothly connected. The second contact surface of the second support rod is formed by a second concave surface and a second convex surface distributed along the length direction, and the second concave surface and the second convex surface are smoothly connected. When inserted into the center hole of the core, the first support rod and the second support rod are staggered in the length direction, and the first convex surface and the second concave surface are in contact, and the first concave surface and the second convex surface are in contact. This makes the core support rod structure smaller in size in this state, making it easier to insert into the center hole. This is achieved through the relative sliding of the first support rod and the second support rod. After the first and second support rods are inserted into place, the first and second convex surfaces fit together, making the size of the core support rod structure larger to further fill the gap between the core support rod structure and the center hole when the first and second support rods are staggered. Thus, the first and second support sides can jointly support the various layers of the core structure, which not only avoids the problem of the core support rod structure being difficult to insert into the center hole after winding, but also achieves effective support of the core by the core support rod structure, offsetting the winding tension of the core in the middle / inner ring position (positive / negative electrode sheet) and the expansion force of the positive and negative electrode sheets in the later stages of the cycle, thus improving the structural stability and cycle life of the power battery. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram of the core support rod structure in the staggered and attached state according to an embodiment of this application.

[0021] Figure 2 This is a three-dimensional structural diagram of the core support rod structure in the normal support state according to an embodiment of this application.

[0022] Figure 3 yes Figure 1 A cross-sectional schematic diagram of the core support rod structure.

[0023] Figure 4 yes Figure 2 A cross-sectional schematic diagram of the core support rod structure.

[0024] Figure 5 This is a three-dimensional structural diagram of the first support rod in an embodiment of this application.

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

[0026] Figure 7 This is a three-dimensional structural diagram of the second support rod in an embodiment of this application.

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

[0028] Figure 9 This is a three-dimensional structural diagram of the core and core support rod structure according to an embodiment of this application, wherein the first support rod and the second support rod are staggered and attached.

[0029] Figure 10 This is a three-dimensional structural diagram of the core and core support rod structure according to an embodiment of this application, wherein the first support rod and the second support rod are both inserted into place. Detailed Implementation

[0030] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0031] Please see Figures 1 to 10 This application discloses a core support rod structure for inserting 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 into the center hole 11 of the core 10, the first support rod 20 and the second support rod 30 are configured to be laterally fitted together to support the core 10. The first support rod 20 includes a first contact surface 21 and a first support side surface 22. The second support rod 30 includes a second contact surface 31 and a second support side surface 32. The first support rod 20 and the second support rod 30 are laterally fitted together through the first contact surface 21 and the second contact surface 31, and laterally support the core 10 through the first support side surface 22 and the second support side surface 32. At least one region of the first contact surface 21 along its length direction is recessed to form a first concave surface 23. By forming the first concave surface 23, the first... The mating 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 mating surface 31 has at least one region along its length direction that is recessed to form a second concave surface 33. By forming the second concave surface 33, the second mating surface 31 forms a second convex surface 34, and the second concave surface 33 and the second convex surface 34 are smoothly connected. When the central hole 11 is inserted, the first support rod 20 and the second support rod 30 are staggered in the length direction, the first convex surface 24 and the second concave surface 33 are mated, and the first concave surface 23 and the second convex surface 34 are mated. 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 both inserted into place, the first convex surface 24 and the second convex surface 34 are mated.

[0032] In this embodiment, the first contact surface 21 of the first support rod 20 is recessed, forming a first concave surface 23 and a first convex surface 24 distributed along the length direction. The first concave surface 23 and the first convex surface 24 are smoothly connected. The second contact surface 31 of the second support rod 30 is recessed, forming a second concave surface 33 and a second convex surface 34 distributed along the length direction. The second concave surface 33 and the second convex surface 34 are smoothly connected. When inserted into the center hole 11 of the core 10, the first support rod 20 and the second support rod 30 are staggered in the length direction, the first convex surface 24 and the second concave surface 33 are in contact, and the first concave surface 23 and the second convex surface 34 are in contact. This makes the core support rod structure smaller in size in this state, making it easier to insert into the center hole 11. The relative sliding of the support rods 30, after the first support rod 20 and the second support rod 30 are both inserted into place, the first convex surface 24 and the second convex surface 34 fit together, making the size of the core support rod structure larger, so as 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 together. Thus, 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 the core support rod structure being difficult to insert into the center hole 11 after winding, but also realizes the effective support of the core support rod structure for the core 10, offsetting the winding tension of the middle / inner ring position (positive / negative electrode sheet) of the core 10 and the expansion force of the positive and negative electrode sheets in the later stage of the cycle, thus improving the structural stability and cycle life of the power battery.

[0033] Because 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 also smoothly connected, it is convenient for the first convex surface 24 to slide relative to the second concave surface 33 and the second convex surface 34, and for the second convex surface 34 to slide relative to the first concave surface 23 and the first convex surface 24. Specifically, the first concave surface 23 and the first convex surface 24, as well as the second concave surface 33 and the second convex surface 34, are all smoothly connected by inclined surface X.

[0034] In some embodiments, the first support rod 20 has alternating first concave surfaces 23 and first convex surfaces 24 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 has alternating second concave surfaces 33 and second convex surfaces 34 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 located in its 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 located in its 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 both inserted into place, the three first convex surfaces 24 and the three second convex surfaces 34 are fitted together in a corresponding manner.

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

[0037] In some embodiments, a guide groove 25 extending along its length is formed on the first support rod 20, and the guide groove 25 is open on one side facing the first concave surface 23 and the first convex surface 24; a guide protrusion 35 extending along its length is formed on the side where the second concave surface 33 and the second convex surface 34 are located, and the guide protrusion 35 is slidably disposed in the guide groove 25 along its length. By means of the cooperation between 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, the first support rod 20 has a plurality of first permeation holes 26 formed therethrough to connect the guide groove 25 and the outside. The first permeation holes 26 allow the electrolyte inside and outside the first support rod 20 to flow freely through the first permeation holes 26.

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

[0040] In some embodiments, the second support rod 30 has a liquid injection through-hole 36 extending along its length, and a plurality of second permeation holes 37 are formed on the second support rod 30, extending laterally to connect the liquid injection through-hole 36 with the outside. The liquid injection through-hole 36 allows liquid to be injected into it, and the second permeation holes 37 allow electrolyte inside and outside the second support rod 30 to flow freely through them.

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

[0042] In some embodiments, after the first support rod 20 and the second support rod 30 are both inserted into place, the first convex surface 24 and the second convex surface 34 fit together to make the core support rod structure cylindrical overall. That is, the first support side surface 22 and the second support side surface 32 are each part of the same cylindrical surface. It should be noted that being cylindrical overall does not mean being strictly cylindrical; for example, in specific examples, a cross-section 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 generally semi-cylindrical, 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 generally semi-cylindrical, 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 central hole 11 in the lateral direction defined by the cut surface, and since the width of the cut surface is limited, it will not affect the support of the core 10.

[0044] In a specific example, along the length of the first support rod 20, continuous first cut surfaces 28 are formed on both sides of the first support rod 20. Along the length of the second support rod 30, continuous second cut surfaces 38 are formed on both sides of the second support rod 30.

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

[0046] In some embodiments, 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 materials of the first support rod 20 and the second support rod 30 may be PP injection molding, ceramic, etc., without specific limitations.

[0048] Please see Figures 1 to 10 This application also discloses a power battery, including a housing (not shown), a core 10, and a core support rod structure as described above. The core 10 is sleeved inside the housing, and the core support rod structure is inserted into the central hole 11 of the core 10.

[0049] In this embodiment, when inserting the core 10 into the center hole 11, the first support rod 20 and the second support rod 30 are staggered in the length direction, the first convex surface 24 and the second concave surface 33 are in contact, and the first concave surface 23 and the second convex surface 34 are in contact. This makes the core support rod structure smaller in size in this state, making it easier to insert into the center hole 11. Through the relative sliding of the first support rod 20 and the second support rod 30, after both 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 in contact, making the core support rod structure smaller in size. The increased size further fills 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. As a result, the first support side 22 and the second support side 32 can jointly support the various layers of the core 10. This not only avoids the problem of the core support rod structure being difficult to insert into the center hole 11 after winding, but also achieves effective support of the core 10 by the core support rod structure. It also counteracts the winding tension of the middle / inner ring position (positive / negative electrode sheet) of the core 10 and the expansion force of the positive and negative electrode sheets in the later stages of the cycle, thereby improving the structural stability and cycle life of the power battery.

[0050] This application also discloses an assembly method for a power battery as described above, including:

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

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

[0053] Force is applied to the other of the first support rod 20 and the second support rod 30, causing it to slide relative to the first support rod 20 and the second support rod 30 toward the bottom of the shell until it touches the bottom of the shell. The first convex surface 24 and the second convex surface 34 are in contact (when both the first support rod 20 and the second support rod 30 are inserted into place). The first support side surface 22 and the second support side surface 32 provide lateral support to each layer of the core 10.

[0054] In a specific embodiment, when accurately inserted into the central hole 11, the first support rod 20 and the second support rod 30, as... Figure 9 The two supports are staggered and fitted. When both are fully inserted, the fit between the second support rod 30 and the second support rod 30 is as follows: Figure 10 As shown.

[0055] The above-disclosed examples are merely preferred embodiments of this application, intended to facilitate understanding and implementation by those skilled in the art. They should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the scope of this application are still within the scope of this application.

Claims

1. A core support rod structure for inserting 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. After being assembled into the center hole of the core, the first support rod and the second support rod are configured to be laterally fitted together to support the core. The first support rod includes a first contact surface and a first support side surface, and the second support rod includes a second contact surface and a second support side surface. The first support rod and the second support rod are laterally fitted together through the first contact surface and the second contact surface, and laterally support the core through the first support side surface and the second support side surface. At least one region of the first contact surface along its length direction is recessed to form a first concave surface. By forming the first concave surface, the first contact surface is shaped... The first concave surface and the first convex surface are smoothly connected. At least one region of the second mating surface along its length direction is recessed to form a second concave surface. By forming the second concave surface, the second mating surface forms a second convex surface. The second concave surface and the second convex surface are smoothly connected. When the central hole is inserted, the first support rod and the second support rod are staggered in the length direction. The first convex surface and the second concave surface are mated, and the first concave surface and the second convex surface are mated. 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 both inserted into place, the first convex surface and the second convex surface are mated.

2. The core support rod structure according to claim 1, characterized in that, The first support rod has alternating first concave surfaces and first convex surfaces in the length direction; the second support rod has alternating second concave surfaces and second convex surfaces in the length direction.

3. The core support rod structure according to claim 2, characterized in that, The first support rod includes three first convex surfaces located at its middle part and two ends, and two first concave surfaces located between the first convex surfaces; the second support rod includes three second convex surfaces located at its middle part and two 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 together in a corresponding manner.

4. The core support rod structure according to claim 1, characterized in that, The first support rod has a guide groove extending along its length, and the guide groove is open to the side facing the first concave surface and the first convex surface; the second support rod has a guide protrusion extending along its length on the side where the second concave surface and the second convex surface are located, and the guide protrusion is slidably disposed in the guide groove along its length.

5. The core support rod structure according to claim 4, characterized in that, The first support rod has a plurality of first permeation holes formed therethrough to connect the guide groove and the outside.

6. The core support rod structure according to claim 1, characterized in that, The second support rod has a liquid injection through hole extending along its length, and a plurality of second permeation holes are formed on the second support rod to connect the liquid injection through hole with the outside.

7. The 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 core support rod structure is cylindrical as a whole.

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

9. A power battery, characterized in that, It includes a housing, a core, and a core support rod structure as described in any one of claims 1 to 8, wherein the core is fitted inside the housing and the core support rod structure is inserted into the central hole of the core.

10. The assembly method of the power battery according to claim 9, characterized in that, include: The first support rod and the second support rod are staggered in the length direction so that the first convex surface and the second concave surface are in contact, and the first concave surface and the second convex surface are in contact. The first and second support rods, which are staggered and joined together, are inserted into the central hole, with one of the first and second support rods touching the bottom of the housing. Force is applied to the other of the first and second support rods, causing it to slide relative to the first and second support rods toward the bottom of the shell until it touches the bottom of the shell. The first convex surface and the second convex surface are in contact, and the first support side and the second support side provide lateral support to each layer of the core structure.

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