Winding mechanism, winding core and single battery

Abstract

The utility model provides a winding mechanism, a winding core and a single battery, and relates to the technical field of batteries. According to the winding mechanism, the supporting component is located on the outer side of the winding needle, the winding radius of the winding core of the follow-up part is increased, the perimeter of the winding core of the follow-up part is increased, and therefore the winding core with the increased perimeter is not tightly attached to the part, wound on the inner side of the winding core, of the winding core in the prior art any more; therefore, an expansion space is provided for the volume change of the pole piece, and the situations that the pole piece is extruded and deformed, the cycle service life of the battery cell is influenced, sodium / lithium precipitation of the pole piece is caused, internal short circuit is induced, and the use safety of the battery cell is influenced are avoided.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a winding mechanism, a winding core, and a single battery. Background Art

[0002] With the continuous development of the new energy market, the demand for lithium and sodium batteries is increasing. In particular, spiral wound cells have become the focus of attention due to their advantages such as high safety, high energy density and low cost.

[0003] In existing technology, wound battery cells primarily consist of a separator and positive and negative electrode sheets. During the manufacturing process, the separator is clamped by a winding needle, and then the negative and positive electrodes are cut and wound around the needle. This method creates a core that is tightly bonded to the positive and negative electrode sheets due to the winding tension.

[0004] However, during long-term charge and discharge cycles of lithium / sodium batteries, the expansion of the electrodes creates tension. The inner electrode is constrained by the outer electrode, preventing the release of tension between the electrodes. Over time, the electrodes can become squeezed and deformed, shortening the battery's cycle life and leading to sodium / lithium deposition. This can cause internal short circuits and compromise the battery's safety. Utility Model Content

[0005] In view of this, the present application provides a winding mechanism, a winding core and a single battery, the purpose of which is to solve the above technical problems to a certain extent.

[0006] In a first aspect, the present application provides a winding mechanism, comprising:

[0007] A winding needle having a predetermined extension direction, the winding needle being used to wind the positive electrode sheet, the negative electrode sheet, and the separator to form a winding core;

[0008] A support member extending along the predetermined extension direction, the support member being used to support the positive electrode sheet, the negative electrode sheet and the separator, the support member being capable of being arranged on the outside of the winding needle so as to be arranged side by side with the winding needle, and the support member being capable of being removed from the outside of the winding needle.

[0009] Based on the above scheme, preferably, the support member can move away from the winding needle from the initial position outside the winding needle at least along the radial direction of the winding core to outwardly support the positive electrode sheet, the negative electrode sheet and the separator, and the support member can also approach the winding needle to return to the initial position.

[0010] Based on any of the above solutions, preferably, the length of the support member in the predetermined extension direction is greater than or equal to the length of the winding needle in the predetermined extension direction;

[0011] Ends of the support member and the winding needle on the same side of the predetermined extending direction are flush.

[0012] Based on any of the above solutions, preferably, the supporting member includes a first surface away from the winding needle, and at least a portion of the first surface is a cylindrical surface.

[0013] Based on any of the above solutions, preferably, the first surface is a cylindrical surface, or the first surface includes a plurality of cylindrical surfaces connected in sequence.

[0014] Based on any of the above solutions, preferably, the supporting member includes a second surface facing the winding needle, and a curvature of the second surface toward the winding needle is lower than a curvature of the first surface toward the winding needle.

[0015] Based on any of the above schemes, preferably, the winding mechanism also includes a force-applying member, which is arranged between the winding needle and the supporting member, the force-applying member is connected to the supporting member, the force-applying member is spaced apart from the winding needle, and the force-applying member drives the supporting member to remove the supporting member from the outside of the winding needle.

[0016] Based on any of the above solutions, preferably, the winding mechanism further includes:

[0017] A base, the base having a mounting surface, one end of the winding needle being connected to the mounting surface, and the base further having a recessed portion provided on the mounting surface;

[0018] a piston movably disposed in the recess, the piston being connected to the support member, and the piston being capable of driving the support member so that the support member is accommodated in the recess and extends out of the recess to the outside of the winding needle;

[0019] a spring connected to the piston, disposed in the recess, and configured to apply a force to the piston away from the spring;

[0020] A valve component is provided on an inner wall of the recess and can extend into the recess to abut against a side of the piston close to the spring.

[0021] In a second aspect, the present application provides a winding core, which is wound by the winding mechanism as described above, and includes winding layers with different winding radii.

[0022] In a third aspect, the present application provides a single cell battery, wherein the single cell battery includes the winding core as described above.

[0023] According to the winding mechanism provided in the present application, when winding the positive electrode sheet, the negative electrode sheet and the separator, as the winding needle winds the positive electrode sheet, the negative electrode sheet and the separator, when a certain number of turns are wound, the support member and the winding needle are arranged side by side to support the positive electrode sheet, the negative electrode sheet and the separator, and the winding continues on this basis. After the winding is completed, the support member is removed from the outside of the winding needle to complete the winding process, and the winding mechanism is pulled out from the winding core, that is, the needle pulling process is implemented.

[0024] In this way, after the support structure is located on the outside of the winding needle, the subsequent part of the core continues to be wound around the outside of the support structure, so that the winding radius of this part of the core increases, and the circumference of the subsequent part of the core increases. In this way, the core with increased circumference is no longer tightly fitted with the part of the core that has been completed wound on its inner side as in the prior art, which provides expansion space for the volume change of the electrode, avoids the electrode from being squeezed and deformed, affects the cycle life of the battery cell, causes sodium / lithium deposition on the electrode, induces internal short circuit, and affects the safety of the battery cell.

[0025] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A schematic diagram of a two-dimensional diagram of a winding mechanism provided according to an embodiment of the present application is shown.

[0028] Figure 2 A schematic diagram of a cross-sectional view of a winding mechanism provided according to an embodiment of the present application is shown.

[0029] Reference numerals:

[0030] 5-housing; 6-base; 7-piston; 8-spring; 9-valve member; 10-winding needle; 20-support member. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solution of this application in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0032] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0034] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0035] According to the winding mechanism provided in the embodiment of the present application, the following will be combined with Figure 1 and Figure 2 The structure and working principle of the winding mechanism are described in detail.

[0036] According to an embodiment of the present application, the winding mechanism includes a winding needle 10 and a support member 20. In the embodiment, the winding needle 10 has a predetermined extension direction and is used to wind the positive electrode sheet, the negative electrode sheet, and the separator to form a winding core. In the embodiment, the support member 20 extends along the predetermined extension direction and is used to support the positive electrode sheet, the negative electrode sheet, and the separator. The support member 20 can be disposed outside the winding needle 10 so as to be arranged side by side with the support member 20 and the winding needle 10.

[0037] In this way, according to the winding mechanism provided in the embodiment of the present application, when winding the positive electrode sheet, the negative electrode sheet and the diaphragm, as the winding needle 10 winds the positive electrode sheet, the negative electrode sheet and the diaphragm, when a certain number of turns are wound, the support member 20 is arranged side by side with the winding needle 10, thereby supporting the positive electrode sheet, the negative electrode sheet and the diaphragm, and the winding continues on this basis. After the winding is completed, the support member 20 is removed from the outside of the winding needle 10 to complete the winding process, and the winding mechanism is pulled out from the winding core, that is, the needle pulling process is implemented.

[0038] In this way, after the support structure 20 is located on the outside of the winding needle 10, the subsequent part of the core continues to be wound around the outside of the support structure, so that the winding radius of this part of the core increases, and the circumference of the subsequent part of the core increases. In this way, the core with increased circumference is no longer tightly fitted with the part of the core that has been completed wound on its inner side as in the prior art, which provides expansion space for the volume change of the electrode, avoids the electrode from being squeezed and deformed, affects the cycle life of the battery cell, causes sodium / lithium deposition on the electrode, induces internal short circuit, and affects the safety of the battery cell.

[0039] In the embodiment, the winding needle 10 may be, for example, an existing winding needle 10 . As the winding needle 10 , the winding needle 10 itself may have an axial direction, and the axial direction may be the predetermined extension direction mentioned above.

[0040] In the embodiment, the support member 20 and the winding needle 10 have the same extension direction, that is, as described above, the support member 20 also extends along a predetermined extension direction.

[0041] In an embodiment, the support member 20 can move away from the winding needle 10 from its initial position outside the winding needle 10 at least along the radial direction of the winding core to outwardly support the positive electrode sheet, the negative electrode sheet and the separator, and the support member 20 can also move close to the winding needle 10 to return to its initial position.

[0042] In an embodiment, the support member 20 is capable of extending at least radially away from the winding needle 10 in the winding core. This means that as the support member 20 moves away from the winding needle 10, at least one component of its movement occurs radially with respect to the winding core. This component causes the distance between the support member 20 and the winding needle 10 to increase radially with respect to the winding core, thereby providing a larger winding radius for the subsequent winding portion of the winding core, thereby providing a larger winding circumference. As an example, the support member 20 is preferably capable of moving radially with respect to the winding core, and its movement will be described below. Furthermore, in an embodiment, radial movement of the support member 20 can be achieved by adding a cylinder to the force-applying member described below to drive the force-applying member in lateral motion.

[0043] In an embodiment, the initial position of the support member 20 relative to the winding needle 10 can be outside the winding needle 10 and relatively close to it. This allows the distance between the support member 20 and the winding needle 10 to be relatively small in the initial position of the support member 20, without affecting the winding radius of the winding core at the beginning of winding. Furthermore, it should be noted that in an embodiment, the support member 20 can not only be moved away from the winding needle 10 in the radial direction of the winding core, but can also be moved closer to the winding needle 10 in the radial direction of the winding core, thereby returning to its initial position.

[0044] According to the winding mechanism provided by the embodiment of the present application, the length of the support member 20 in the predetermined extension direction is greater than or equal to the length of the winding needle 10 in the predetermined extension direction.

[0045] In this way, according to the winding mechanism provided in the embodiment of the present application, the support member 20 has a length in the predetermined extension direction that is equivalent to or greater than the winding needle 10, which is beneficial for the support member 20 to wind in a more stable posture when supporting the positive electrode sheet, the negative electrode sheet and the diaphragm, thereby helping to improve the stability of the winding mechanism operation.

[0046] In an embodiment, as an example, the support member 20 may be of the same length as the winding needle 10 . In other examples, the support member 20 may be longer than the winding needle 10 , thereby extending beyond a portion of the winding core in a predetermined extension direction.

[0047] According to the winding mechanism provided by the embodiment of the present application, the ends of the support member 20 and the winding needle 10 on the same side of the predetermined extension direction are flush. This allows the winding core on at least the side where the support member 20 and the winding needle 10 are flush to be effectively supported and smoothly wound.

[0048] In an embodiment, based on the above example, if the length of the support member 20 is the same as that of the winding needle 10, the two ends of the support member 20 can be substantially flush with the two ends of the winding needle 10, so that the two axial ends of the winding core are effectively supported and wound smoothly.

[0049] In addition, in other examples, when the length of the support member 20 is greater than the length of the winding needle 10, one end of the support member 20 is flush with the winding needle 10, and the other end will extend beyond the winding needle 10. This arrangement can also ensure that the two axial ends of the winding core are effectively supported and wound smoothly.

[0050] According to the winding mechanism provided in an embodiment of the present application, the support member 20 may include a first surface distal from the winding needle 10, with at least a portion of the first surface being a cylindrical surface. In the embodiment, the first surface of the support member 20 is essentially the surface that directly contacts the winding core. Because the positive electrode sheet, negative electrode sheet, and separator are curved during winding, at least a portion of the first surface being a cylindrical surface allows the first surface to better contact the curved positive electrode sheet, negative electrode sheet, and separator, preventing the curved positive electrode sheet, negative electrode sheet, and separator from being crushed by the first surface.

[0051] According to the winding mechanism provided in the embodiments of the present application, the first surface can be a cylindrical surface, or the first surface can include multiple cylindrical surfaces connected in sequence. In the latter example, the multiple cylindrical surfaces can smoothly transition without forming outwardly protruding "edges." In other words, the curvature of the first surface can continuously change.

[0052] According to the winding mechanism provided in an embodiment of the present application, the support member 20 may include a second surface facing the winding needle 10. The second surface is less curved toward the winding needle 10 than the first surface. In an embodiment, the second surface may be more gently curved than the first surface. For example, the second surface may be a cylindrical surface. This more gently curved second surface facilitates the placement of a component inside the support member 20 that provides power for the movement of the support member 20.

[0053] According to the winding mechanism provided in the embodiment of the present application, the winding mechanism further includes a force-applying member, which may not be connected to the winding needle 10 but is an independent force-applying member that can be connected to the support member 20 described above to apply force to the support member 20. In the embodiment, as an example, the force-applying member can be a rod-shaped structure connected to the inner side of the support member 20, which can be further connected to a drive mechanism such as a cylinder located above the winding needle 10.

[0054] The winding mechanism provided in the embodiment of the present application is different from the above examples. Figure 2 In the example given, the winding mechanism further comprises a base 6, a piston 7, a spring 8 and a valve member 9. Figure 2 As shown, the base 6 has a mounting surface, which can be, for example, the upper surface of the base 6. One end of the winding needle 10, for example the lower end, can be connected to the mounting surface. The base 6 can also have a recess arranged on the mounting surface, which can be formed as a substantial blind hole located on the base 6.

[0055] In an embodiment, the piston 7 is movably disposed within the recess, for example, the piston 7 can be raised and lowered. In an embodiment, the piston 7 is connected to the support member 20, for example, the lower end of the support member 20 is connected to the piston 7. The piston 7 can drive the support member 20 so that the support member 20 is accommodated within the recess (i.e., the piston 7 descends, bringing the support member 20 into and accommodating the recess), and so that the support member 20 extends out of the recess to the outside of the winding needle 10 (i.e., the piston 7 ascends, extending the support member 20 from the recess).

[0056] In an embodiment, the spring 8 can be connected to the piston 7, and the spring 8 can be arranged in the recess. The spring 8 can be, for example, a coil spring, the lower end of which is connected to the inside of the recess, such as the bottom 6 of the recess, and the other end is connected to the bottom 6 of the piston. The spring 8 is used to apply a force to the piston 7 away from the spring 8, that is, the spring 8 can be compressed.

[0057] In an embodiment, the valve member 9 can be disposed on the inner wall of the recess, and the valve member 9 can extend into the recess to abut against the side of the piston 7 close to the spring 8. Specifically, the valve core of the valve member 9 can extend horizontally into the recess, thereby being stuck under the piston, preventing the piston 7 from shaking up and down, thereby ensuring the stability of the support member 20.

[0058] In an embodiment, the piston 7 can be driven, for example, by a cylinder (not shown) located below the base 6. In addition, in an embodiment, the winding mechanism can further include a housing 5 buckled in the recess, the spring 8 and the piston 7 can both be located in the housing, and the top of the housing 5 is opened for the support member 20 to pass through.

[0059] In an embodiment, the valve member 9 may be a solenoid valve, for example, so that the opening and closing of the battery valve can be remotely controlled by an external control mechanism that is in communication with the solenoid valve. Figure 2 In the example given, the support member 20 can be ejected from the recess under the elastic force of the spring 8, so as to be arranged side by side with the winding needle 10, and in this example, the support member 20 may not be radially away from the winding needle 10. Before the support member 20 is ejected, the elastic force of the spring 8 may be overcome by a cylinder (not shown), or Figure 2 Another solenoid valve can be further provided below the solenoid valve to be clamped on the upper side of the piston 7 to prevent the piston 7 from rising.

[0060] According to the second aspect of the embodiment of the present application, a winding core is provided, which is wound by the above winding mechanism. Therefore, the winding core includes winding layers with different winding radii, thereby providing expansion space for the volume change of the electrode, avoiding deformation or even breakage of the electrode due to local force, and improving the stability and safety of the electrical performance of the battery cell.

[0061] According to a third aspect of an embodiment of the present application, a single cell is provided. The single cell includes the winding core as described above and has the above beneficial effects, which will not be described in detail here.

[0062] The above are only preferred embodiments of the present application and do not limit the scope of protection of the present application. All equivalent structural transformations made based on the contents of the present application specification and drawings under the innovative concept of the present application, or direct / indirect application in other related technical fields are included in the scope of protection of the present application.

Claims

1. A winding mechanism, characterized in that: The winding mechanism comprises: A winding needle having a predetermined extension direction, the winding needle being used to wind the positive electrode sheet, the negative electrode sheet, and the separator to form a winding core; A support member extending along the predetermined extension direction, the support member being used to support the positive electrode sheet, the negative electrode sheet and the separator, the support member being capable of being arranged on the outside of the winding needle so as to be arranged side by side with the winding needle, and the support member being capable of being removed from the outside of the winding needle.

2. The winding mechanism according to claim 1, characterized in that: The support member can move away from the winding needle from an initial position outside the winding needle at least along the radial direction of the winding core to outwardly support the positive electrode sheet, the negative electrode sheet and the separator, and the support member can also move closer to the winding needle to return to the initial position.

3. The winding mechanism according to claim 1, wherein: The length of the support member in the predetermined extension direction is greater than or equal to the length of the winding needle in the predetermined extension direction; Ends of the support member and the winding needle on the same side of the predetermined extending direction are flush.

4. The winding mechanism according to claim 1, wherein: The supporting member includes a first surface facing away from the winding needle, at least a portion of the first surface being a cylindrical surface.

5. The winding mechanism according to claim 4, characterized in that: The first surface is a cylindrical surface, or the first surface includes a plurality of cylindrical surfaces connected in series.

6. The winding mechanism according to claim 4, characterized in that: The supporting member includes a second surface facing the winding needle, wherein the curvature of the second surface toward the winding needle is lower than the curvature of the first surface toward the winding needle.

7. The winding mechanism according to claim 1, characterized in that: The winding mechanism further includes a force member, which is disposed between the winding needle and the support member, is connected to the support member, is spaced apart from the winding needle, and drives the support member to remove the support member from the outside of the winding needle.

8. The winding mechanism according to claim 1, wherein: The winding mechanism further comprises: A base, the base having a mounting surface, one end of the winding needle being connected to the mounting surface, and the base further having a recessed portion provided on the mounting surface; a piston movably disposed in the recess, the piston being connected to the support member, and the piston being capable of driving the support member so that the support member is accommodated in the recess and extends out of the recess to the outside of the winding needle; a spring connected to the piston, disposed in the recess, and configured to apply a force to the piston away from the spring; A valve component is provided on an inner wall of the recess and can extend into the recess to abut against a side of the piston close to the spring.

9. A winding core, characterized in that: The winding core is wound by the winding mechanism according to any one of claims 1 to 8, and the winding core includes winding layers with different winding radii.

10. A single cell battery, characterized in that: The single battery includes the winding core according to claim 9 .

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