Roll core for winding secondary battery diaphragm

Abstract

The present invention relates to a winding core for winding a secondary battery separator, which is used for stably winding an electrode assembly, and is characterized in that two winding cores for winding a separator are arranged at the upper part and the lower part, and when the separator is wound, the upper winding core and the lower winding core move towards the middle to be connected, so that a film is clamped between a convex part of the upper winding core and a concave part of the lower winding core to be fastened and wound. According to the present invention, two winding cores for winding a diaphragm are arranged on the upper and lower parts, a rectangular convex part is formed on the lower surface of the upper winding core, a rectangular concave part is formed on the upper surface of the lower winding core, and when the diaphragm is wound, the upper winding core and the lower winding core move from both sides to the middle, so that the diaphragm is positioned between the convex part of the upper winding core and the concave part of the lower winding core. The winding core is fastened and rotated, and the film is wound.

Description

Technical Field

[0001] The present invention relates to a secondary battery diaphragm winding core used for stably winding an electrode assembly. Specifically, the core has two diaphragm winding cores, a convex portion is formed on the bottom of the upper core and a concave portion is formed on the top of the lower core. When winding the diaphragm, when the upper core and the lower core move from both sides to the middle, the film is clamped between the convex portion of the upper core and the concave portion of the lower core and is tightened. The core is rotated by a rotating body, thereby causing the film to be wound. Background Art

[0002] Generally speaking, with the development of mobile device technology and the increase in demand, the demand for secondary batteries as energy sources is rapidly increasing, and lithium secondary batteries with high energy density and discharge voltage among secondary batteries have been commercialized.

[0003] Such secondary batteries are classified according to the shape of the battery case into cylindrical batteries and square batteries in which the electrode assembly is built into a cylindrical or square metal can, and pouch-type batteries in which the electrode assembly is built into a pouch-type casing of an aluminum laminate.

[0004] This electrode assembly is a power generation element composed of a stacked structure of positive electrode / separator / negative electrode and capable of charging and discharging. It is divided into a roll type in which a separator is sandwiched between long sheets of positive and negative electrodes coated with active materials and wound up, and a stacked type in which multiple positive and negative electrodes are stacked in sequence with a separator sandwiched between them.

[0005] The advantages of the rolled electrode assembly are that it is easy to manufacture and has a high energy density per weight unit. The manufacturing process of the rolled electrode assembly includes a process of clamping a roll core into the end of the positive electrode / separator / negative electrode stack, then winding it into a cylindrical shape and removing the roll core.

[0006] In the past, the winding core was a rod-shaped component, separated by a length corresponding to the width of the stack, so that the sheet stack was inserted into one side end extending by a predetermined length. In addition, this winding core has a structure in which two semicircles face each other in cross section. Therefore, when winding the electrode assembly, the two semicircles twist with each other as the electrode assembly rotates at high speed. After winding, the winding is staggered between each sheet, which leads to eccentricity of the electrode assembly.

[0007] Therefore, the electrodes of the electrode assembly cannot be positioned accurately and fluctuate, and the winding core becomes unstable when being separated from the electrode assembly. Therefore, there is a disadvantage that the winding stability of the electrode assembly is reduced.

[0008] Furthermore, conventional electrode assemblies have the disadvantage that they are highly likely to fail, thereby reducing battery performance and battery safety, such as electrode disconnection and internal short circuits.

[0009]

Prior technical literature

[0010] [Patent Literature]

[0011] Patent application number 10-2021-0058504;

[0012] Patent application number 10-2011-0001058. Summary of the Invention

[0013] Technical issues

[0014] In order to solve the defects that have existed in the past as described above, the present invention provides a secondary battery diaphragm winding core, which has two diaphragm winding cores on the upper and lower sides, a longer rectangular convex portion is formed on the lower side of the upper core and a longer rectangular concave portion is formed on the upper side of the lower core. When winding the diaphragm, the diaphragm is clamped between the convex portion of the upper core and the concave portion of the lower core and tightened, and then wound by a rotating body.

[0015] Technical Solution

[0016] To achieve the above-mentioned purpose, the winding core for winding the secondary battery diaphragm of the present invention is, preferably, composed of an upper winding core with a longer rectangular convex portion formed at the bottom and a lower winding core with a longer rectangular concave portion formed at the top, so that the diaphragm is sandwiched between the convex portion and the concave portion respectively formed on the winding core when the upper and lower winding cores are tightened, and is tightened and rotated so that the membrane is wound.

[0017] Preferably, the present invention forms two protrusions on the bottom of the upper winding core and two recesses on the top of the lower winding core, so that each protrusion can be inserted into each recess.

[0018] Beneficial effects

[0019] According to the present invention as described above, its advantageous effect lies in that the convex portion and the concave portion are formed between the upper and lower winding cores, and the diaphragm is wound between the convex portion and the concave portion respectively formed on the upper and lower winding cores, so that the membrane is wound stably.

[0020] The present invention can reduce the twisting phenomenon of the sheet-type stacked body when it is wound, and will not damage the stacked body, but can be wound in a state with increased non-circularity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a perspective view of the present invention;

[0022] Figure 2 It is a side view and a cross-sectional view of the present invention;

[0023] Figure 3 It is a perspective view showing the upper core protrusion and the lower core groove of the present invention in a simple and easy-to-understand manner;

[0024] Figure 4 It is a cross-sectional view showing the raised portion and the recessed portion of the winding core of the present invention.

[0025]

Explanation of symbols

[0026] 1: Upper core; 2: Lower core;

[0027] 3: convex part; 4: concave part;

[0028] 5: membrane; 6, 7: rotating fixing parts. DETAILED DESCRIPTION

[0029] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0030] Figure 1 is a perspective view of the present invention, Figure 2 It is a side view and a cross-sectional view of the present invention, Figure 3 This is a perspective view showing the upper core protrusion and lower core groove of the present invention in a simple and easy-to-understand manner. Figure 4 1 is a cross-sectional view showing the raised and recessed portions of the winding core of the present invention. As shown in the figure, the winding core of the present invention is composed of an upper winding core 1 and a lower winding core 2.

[0031] The upper winding core 1 is formed with a rotating fixing portion 6 at one end thereof for rotating the winding core. The rotating body is inserted into the rotating fixing portion 6 to rotate the winding core. A long rectangular protrusion 3 is formed at the bottom of the upper winding core 1 .

[0032] A rotating fixing portion 7 for rotating the core is formed at the other end of the lower core 2 , and a rotating body is inserted into the rotating fixing portion 7 to rotate the core. A long rectangular recess 4 is formed on the upper surface of the lower core 2 .

[0033] When the upper core 1 and the lower core 2 are fastened on both sides, the raised portions 3 formed on the upper core 1 and the lower core 2 are inserted into the recessed portions 4, and the film 5 is sandwiched between the raised portions 3 and the recessed portions 4, so that the upper core 1 and the lower core 2 are fastened into one, and the rotating body is inserted into the rotating fixing portions 6 and 7 formed on the two ends, thereby causing the core to rotate.

[0034] Next, the effects of the present invention constructed as described above will be described.

[0035] The core of the present invention is as follows Figures 1 to 3As shown in the figure, it consists of an upper core 1 and a lower core 2. A rectangular protrusion 3 is provided on the bottom of the upper core 1, and a rectangular recessed portion 4 is provided on the top of the lower core. When the lower core 2 and the upper core 1 move toward the center on the left and right sides respectively, the protrusion 3 of the upper core 1 is directly inserted into the recessed portion 4 of the lower core 2, and then fastened into a core.

[0036] In this state, the film 5 is inserted between the upper winding core 1 and the lower winding core 2 and wound. The film 5 is sandwiched between the convex portion 3 of the upper winding core 1 and the concave portion 4 of the lower winding core 2 and wound by the rotation of the rotating body.

[0037] In the embodiment, a protrusion 3 and a recessed portion 4 are respectively formed on the upper winding core 1 and the lower winding core 2, so that the protrusion 3 is inserted into the recessed portion 4 and fastened. Another embodiment is that, for example, two protrusions and recessed portions can be respectively formed on the upper winding core 1 and the lower winding core 2, so that the multiple protrusions are inserted into the multiple recessed portions and fastened.

[0038] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Those skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified or changed by adding components, changing, deleting or supplementing them. However, these modifications or changes do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions described in the embodiments of the present invention.

Claims

1. A winding core for winding a separator for a secondary battery, characterized in that: The diaphragm is wound with two winding cores, one above and one below, with a rectangular raised portion formed at the bottom of the upper winding core and a rectangular recessed portion formed at the top of the lower winding core. When the diaphragm is wound, the upper winding core and the lower winding core move from both sides to the middle so that the film is located between the raised portion of the upper winding core and the recessed portion of the lower winding core, thereby fastening the cores into one and winding the film by rotation.

2. The winding core for winding a separator for a secondary battery according to claim 1, characterized in that: Two protrusions are formed on the lower side of the upper winding core, and two recesses are formed on the upper side of the lower winding core, so that the protrusions are inserted into the recesses.

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