Full-length coil core

Abstract

The utility model provides a full-ear winding core, belonging to the technical field of lithium-ion batteries, including a diaphragm, a pole piece, a pole ear, a center hole, an auxiliary liquid injection port and a winding core, wherein the pole ear is located at the upper and lower ends of the pole piece, the pole piece and the diaphragm are wound to form the winding core, the center hole is located at the center of the winding core surface, and the auxiliary liquid injection port is located between the center hole and the pole ear. The utility model improves the electrolyte filling efficiency while ensuring that the welding requirements of the collector plate are met, and has good practicality.

Description

Technical Field

[0001] The utility model belongs to the technical field of lithium ion batteries, in particular to a full-electrode lug winding core. Background Art

[0002] In order to ensure the welding quality of the current collector during welding, the full-ear process used in cylindrical batteries will be flattened and cut and stacked after the battery cells are wound to tightly compact the adjacent ears. Subsequently, the liquid can only seep to both sides through the center hole. Even if the number of positive and negative pressure cycles of injection is increased to help the electrolyte diffuse, the injection efficiency is still very low, which seriously affects the battery production efficiency. Punching holes in the blank foil at both ends of the ear can speed up the electrolyte filling speed, but punching will affect the strength of the foil, which is easy to be damaged in the flattening process, affecting the flattening effect. At the same time, the metal particles and laser melt beads produced by cutting and stacking will cause battery short circuit and poor K value. Utility Model Content

[0003] The technical problem to be solved by the utility model is to increase the filling speed of electrolyte under the premise of ensuring that the tabs are flattened to meet the subsequent collector plate welding quality requirements, and to provide a full tab winding core in view of the deficiencies of the prior art.

[0004] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0005] A full-electrode-lug winding core comprises a diaphragm, a pole piece, a pole lug, a center hole, an auxiliary liquid injection port and a winding core, wherein the pole lugs are located at the upper and lower ends of the pole piece, the pole piece and the diaphragm are wound to form the winding core, the center hole is located at the center of the winding core surface, and the auxiliary liquid injection port is located between the center hole and the pole lug.

[0006] Furthermore, the tabs on the surface of the winding core are rotationally symmetrical along the center of the center hole.

[0007] Furthermore, the maximum height of the tab is 2-5 mm.

[0008] Furthermore, the pole lug is a fan-shaped pole lug, an isosceles trapezoidal pole lug, an isosceles triangle pole lug or a bilaterally symmetrical sawtooth-edged polygonal pole lug.

[0009] Furthermore, the number of the tabs in each layer of the winding core is 2-8.

[0010] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0011] Compared with the prior art, the utility model provides a full-ear lug winding core, which increases the gap between the ear and the center hole by cutting the ear edge while ensuring that the processed ear meets the welding flatness and strength with the subsequent current collecting plate, thereby improving the electrolyte filling speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the structure of the undie-cut pole piece in Example 1 of the utility model;

[0013] Figure 2 This is a schematic structural diagram of the die-cut pole piece of Embodiment 1 of the utility model;

[0014] Figure 3 This is a top view of the full-electrode lug winding core of Example 1 of the utility model;

[0015] Figure 4 This is a schematic structural diagram of the die-cut pole piece of Embodiment 2 of the present utility model;

[0016] Figure 5 This is a schematic structural diagram of the die-cut pole piece of Embodiment 3 of the present utility model;

[0017] Figure 6 This is a schematic structural diagram of the die-cut pole piece of Embodiment 4 of the present utility model;

[0018] Among them, 1-pole piece, 11-fan-shaped pole ear, 12-center hole, 13-auxiliary injection hole, 14-winding core, 15-isosceles trapezoidal pole ear, 16-isosceles triangle pole ear, 17-left-right symmetrical serrated polygonal pole ear. DETAILED DESCRIPTION

[0019] In order to better understand the present invention, the content of the present invention is further clearly described below in conjunction with the embodiments, but the protection content of the present invention is not limited to the following embodiments. In the following description, a large number of specific details are given in order to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details.

[0020] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0021] In the present invention, unless otherwise clearly specified and limited, the terms such as "connection" shall be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a direct connection, or an indirect connection through an intermediate medium, or it may be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] Example 1

[0023] See also Figure 1-Figure 3 A full-ear winding core, including a diaphragm, a pole piece 1, a pole ear, a center hole 12, an auxiliary liquid injection port 13 and a winding core 14. When the pole piece 1 is coated, a blank area of ​​the pole ear is specified at a certain distance on the upper and lower sides of the metal foil. The upper and lower widths of the blank area are equal to the maximum height of the pole ear during die cutting, and the maximum height of the pole ear is 2-5mm. Subsequently, the coated pole piece is rolled, and the rolling thickness meets the process requirements. Then, the rolled pole piece is cut into sub-rolls of a certain length by a slitting machine. During die cutting, a certain length of the pole ear-free area is reserved at the head of each sub-roll to avoid the pole ear 11 being too large and blocking the center hole 12 during flattening to affect liquid injection. The pole ear is located at the upper and lower ends of the pole piece 1. The pole piece 1 and the diaphragm are wound to form the winding core 14. When the two ends of the winding core 14 are in the flattening process, the pole ear of the pole piece 1 is bent layer by layer from the outside to the inside toward the center hole 12. The tabs on the surface of the winding core 14 are rotationally symmetrical along the center of the center hole 12, the center hole 12 is located at the center of the surface of the winding core 14, the auxiliary liquid injection port 13 is located between the center hole 12 and the tabs, and the tabs are fan-shaped tabs 11. The number of tabs on each layer of the winding core 14 is 2-8. The specific number is determined according to the number of seepage holes of the current collecting plate to be matched and welded, and the number of the seepage holes of the current collecting plate corresponds to the number of the auxiliary liquid injection port 13 to speed up the electrolyte injection efficiency.

[0024] The technical solution provided in the embodiment of the present application can significantly improve the electrolyte injection efficiency by only changing the method of cutting the pole ears in the die-cutting link in the traditional process flow while ensuring welding stability. The fan-shaped pole ears are easy to cut, and the number of pole ears on each layer of battery cells can be flexibly selected according to the distribution and size of the seepage holes of the current collecting plate that needs to be welded, which has good practicality and economy.

[0025] Example 2

[0026] See also Figure 4 The full-electrode-lug winding core of the present utility model embodiment is different from that of embodiment 1 in that:

[0027] In this embodiment, the pole lug is an isosceles trapezoidal pole lug 15, and the outer edge of the auxiliary liquid injection port 13 formed after the flattening process is more regular, which is convenient for subsequent welding.

[0028] Example 3

[0029] See also Figure 5 The full-electrode-lug winding core of the present utility model embodiment is different from that of embodiment 1 in that:

[0030] In this embodiment, the pole ear is an isosceles triangle pole ear 16, which is easy to cut.

[0031] Example 4

[0032] See also Figure 6 The full-electrode-lug winding core of the present utility model embodiment is different from that of embodiment 1 in that:

[0033] In this embodiment, the pole ear is a bilaterally symmetrical serrated polygonal pole ear 17. In the case where a plurality of injection holes are distributed on the welding plate, the auxiliary injection port 13 surrounded by the serrated edge can better fit the upper injection hole to speed up the electrolyte filling.

[0034] Finally, it should be noted that the above embodiments are only preferred embodiments of the present invention, which are only used to illustrate the technical solution of the present invention rather than to limit it. Any modification, improvement, other modification or equivalent replacement made to the technical solution of the present invention by ordinary technicians in this field, as long as they do not depart from the spirit and scope of the technical solution of the present invention, should be included in the protection scope of the present invention.

Claims

1. A full-electrode lug winding core, characterized in that: The invention comprises a diaphragm, a pole piece (1), a pole ear, a center hole (12), an auxiliary liquid injection port (13) and a winding core (14), wherein the pole ear is located at the upper and lower ends of the pole piece (1), the pole piece (1) and the diaphragm are wound to form the winding core (14), the center hole (12) is located at the center of the surface of the winding core (14), and the auxiliary liquid injection port (13) is located between the center hole (12) and the pole ear.

2. The full-tab winding core according to claim 1, characterized in that: The pole lugs on the surface of the winding core (14) are rotationally symmetrical along the center of the center hole (12).

3. The full-tab winding core according to claim 1, characterized in that: The height of the tab is 2-5 mm.

4. The full-tab winding core according to claim 1, characterized in that: The pole lug is a fan-shaped pole lug (11), an isosceles trapezoidal pole lug (15), an isosceles triangle pole lug (16), or a bilaterally symmetrical sawtooth-edge polygonal pole lug (17).

5. The full-tab winding core according to claim 1, characterized in that: The number of the pole tabs on each layer of the winding core (14) is 2-8.

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