A winding needle and mandrel for large cylindrical batteries

Abstract

This utility model belongs to the technical field of winding needles for large cylindrical battery bare cells. It discloses a winding needle and mandrel for large cylindrical batteries, including a mandrel, a winding needle, two layers of separators, a negative electrode sheet, and a positive electrode sheet. The winding needle is inserted into the mandrel. The two layers of separators and the mandrel are fixed together by heat fusion during the pre-winding stage to form the initial winding base. The negative electrode sheet is inserted between the two layers of separators and located at the crack position of the mandrel. The positive electrode sheet is inserted into the gap between the separator and the mandrel. This utility model, through the adaptive insertion of the mandrel and the winding needle, combined with the heat fusion fixing method of the two layers of separators and the mandrel, and the insertion of the negative and positive electrode sheets, effectively solves the technical problems of winding needle deformation and the removal of separators and electrode sheets during the winding of large cylindrical battery bare cells. This improves the stability and yield of bare cell winding and reduces the scrap rate.

Description

Technical Field

[0001] This utility model belongs to the technical field of winding needles for bare cylindrical battery cells, specifically relating to a winding needle and mandrel for large cylindrical batteries. Background Technology

[0002] Against the backdrop of a global energy structure transition towards cleaner and lower-carbon energy sources, large cylindrical battery energy storage technology has become a core means of balancing clean energy and grid stability. Large cylindrical batteries (such as the 120420, 200420, and 300600 models) are gaining increasing market share in the energy storage field due to their advantages, including high single-cell energy, long cycle life, simplified energy storage systems, standardized production processes, high material utilization, easy recycling and dismantling of end-of-life batteries, and high recycling rates.

[0003] Large cylindrical batteries have a diameter of 60-300mm and a length of 100-600mm, with bare cells weighing 6-60kg. Existing winding needles deform during the bare cell winding process, and pulling the winding needles after winding pulls out the separator and electrode sheets, which cannot meet the requirements for winding bare cells of large cylindrical batteries. Furthermore, there are problems such as the winding needles being deformed by the weight of the bare cell, the tension of the electrode sheets and separator during the bare cell winding process, and the bare cell being scrapped after pulling the winding needles out, which are caused by the separation of the separator and electrode sheets. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a winding needle and mandrel for large cylindrical batteries, which effectively solves the technical problems of needle deformation and the removal of separators and electrodes during the winding of bare cells of large cylindrical batteries, improves the stability and yield of bare cell winding, and reduces the scrap rate.

[0005] The technical solution of this utility model is as follows: a winding needle and core rod for large cylindrical batteries, including a core rod, a winding needle, two layers of separators, a negative electrode sheet and a positive electrode sheet. The winding needle is inserted into the core rod. The two layers of separators and the core rod are fixed together by heat fusion during the pre-winding stage to form the initial winding base. The negative electrode sheet is inserted between the two layers of separators and is located at the crack position of the core rod. The positive electrode sheet is inserted into the gap position between the separator and the core rod.

[0006] Furthermore, the mandrel has an outer circle and an inner hexagonal tubular structure.

[0007] Furthermore, the coiling needle is a solid hexagonal rod, and the internal hexagonal hole of the core rod is adapted to the outer contour of the coiling needle.

[0008] Furthermore, it also includes a fixing device, which is fixed to the tail end of the winding needle to fix the relative position of the mandrel and the winding needle during the winding process, preventing them from shifting or loosening.

[0009] Furthermore, the coiling needle is made of metal, specifically tungsten steel, stainless steel, or high-speed steel.

[0010] Furthermore, the diaphragm is made of either polyethylene or polypropylene.

[0011] Furthermore, a top pin is inserted into the first end of the coiled needle.

[0012] Furthermore, the end face of the ejector pin is provided with a slot for receiving the head end of the coiling needle, and the slot is adapted to the head end of the coiling needle.

[0013] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0014] 1. By adapting and inserting the core rod and winding needle, combined with the hot-melt fixing method of the two-layer separator and the core rod, and the insertion of the negative electrode and positive electrode, the technical problems of winding needle deformation and separation and electrode brought out during the winding of bare cells of large cylindrical batteries are effectively solved, thereby improving the stability and yield of bare cell winding and reducing the scrap rate.

[0015] 2. By fixing the core rod and the winding needle at the end of the winding needle, the relative position of the core rod and the winding needle is effectively prevented from shifting or loosening during the winding process, ensuring the consistency of winding and further improving the production quality and efficiency of large cylindrical batteries. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of this utility model during winding;

[0018] Figure 2 This is a schematic diagram of the structure of the mandrel, coiling needle, ejector pin, and fixing device of this utility model;

[0019] Figure 3 This is a schematic diagram of the structure of the coiling needle and fixing device of this utility model;

[0020] Figure 4 This is a schematic diagram of the ejector pin structure of this utility model.

[0021] In the attached image:

[0022] 1. Core rod; 2. Coiling needle; 3. Separator; 4. Negative electrode plate; 5. Positive electrode plate; 6. Pin; 7. Fixing device. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0024] It should be noted that all directional indications in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0025] Please see Figure 1-4 A winding needle and core rod for large cylindrical batteries includes a core rod 1, a winding needle 2, two layers of separators 3, a negative electrode 4 and a positive electrode 5. The core rod 1 is a tubular structure with an outer circle and an inner hexagon. The winding needle 2 is inserted into the core rod 1. The winding needle 2 is a solid hexagonal rod. The hexagonal hole inside the core rod 1 is adapted to the outer contour of the winding needle 2.

[0026] When winding large cylindrical batteries, a core rod 1 with an outer circle and an inner hexagonal tubular structure, and a winding needle 2 made of solid hexagonal rod are selected to ensure a tight fit between the inner hexagonal hole of the core rod 1 and the outer contour of the winding needle 2. Before winding begins, the winding needle 2 is inserted into the core rod 1. The stability of the hexagonal structure effectively prevents the deformation or displacement of the winding needle 2 during the winding process. This structural design not only improves the stability of winding but also avoids the problem of the separator 3 and positive and negative electrode sheets being pulled out when the winding needle 2 is pulled out, thereby improving the yield and production efficiency of winding bare cells for large cylindrical batteries.

[0027] When manufacturing the core rod 1 and winding needle 2 for winding large cylindrical batteries, high-strength metal materials are selected, specifically one of tungsten steel, stainless steel, or high-strength steel. These metal materials have excellent wear resistance, corrosion resistance, and mechanical strength, which can ensure that the core rod 1 and winding needle 2 maintain stable shape and performance during long-term, high-intensity winding operations, and are not easily deformed or damaged.

[0028] During the pre-winding stage, the two diaphragm layers 3 and the mandrel 1 are fixed together by heat fusion to form the initial winding base. A winding needle 2 is inserted into the mandrel 1, and the two diaphragm layers 3 and the mandrel 1 are pre-wound together several times by heat fusion. Heating causes the contact surfaces of the diaphragm layers 3 and the mandrel 1 to partially melt and fuse. After cooling and solidification, the two diaphragm layers 3 are firmly fixed to the mandrel 1, forming a stable and flat initial winding base. This method effectively avoids the problem of diaphragm displacement or detachment in traditional methods, ensuring the continuity and stability of the winding process.

[0029] The negative electrode 4 is inserted between the two layers of separator 3 and located at the crack position of the core rod 1; the positive electrode 5 is inserted into the gap between the separator 3 and the core rod 1. After the two layers of separator 3 and the core rod 1 are heat-fused and fixed, the negative electrode 4 is inserted between the two layers of separator 3 and closely attached to the crack position of the core rod 1, ensuring that the negative electrode 4 and the separator 3 are tightly attached. Then, the positive electrode 5 is inserted into the gap formed by the separator 3 and the core rod 1, so that the negative electrode material area is attached to the positive electrode material area, ensuring that the structure overlaps and aligns consistently.

[0030] A winding needle and core rod for large cylindrical batteries, further comprising a fixing device 7, which is fixed to the tail end of the winding needle 2 to fix the relative position of the core rod 1 and the winding needle 2 during the winding process. By fixing the tail end of the winding needle 2 with the fixing device 7, the relative position of the core rod 1 and the winding needle 2 is effectively prevented from shifting or loosening during the winding process, ensuring winding consistency and further improving the production quality and efficiency of large cylindrical batteries.

[0031] The separator 3 is made of either polyethylene or polypropylene. Both polyethylene and polypropylene are polyolefin materials, characterized by good chemical stability and excellent mechanical properties. They are commonly used materials for battery separators, providing reliable insulation and separation for the positive electrode 5 and negative electrode 4 inside the battery.

[0032] A pin 6 is inserted into the first end of the winding needle 2. The end face of the pin 6 has a slot for receiving the first end of the winding needle 2, and the slot is adapted to the first end of the winding needle 2. The pin 6 provides effective support and guidance for the winding needle 2 during the winding process, preventing the winding needle 2 from bending or deviating due to uneven force.

[0033] Working principle: When winding large cylindrical batteries, a solid hexagonal rod winding needle 2 is inserted into the internal hexagonal hole of the core rod 1 to perform the initial assembly of the winding needle 2 and the core rod 1.

[0034] Next, the two diaphragms 3 and the mandrel 1 are tightly fixed together by heat fusion, followed by several rounds of pre-winding.

[0035] Next, the negative electrode 4 and the positive electrode 5 are inserted sequentially. First, the negative electrode 4 is inserted between the two layers of separator 3, and placed close to the crack in the core rod 1. Then, it is pre-wound once to ensure the initial positioning of the negative electrode 4. Immediately afterward, the positive electrode 5 is inserted into the gap between the separator 3 and the core rod 1, and is also pre-wound once.

[0036] After the negative electrode 4 and the positive electrode 5 are wound, the wound part is glued to fix the winding structure.

[0037] Finally, after ensuring the winding structure is stable, slowly pull the winding needle 2 out of the mandrel 1.

[0038] It should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0039] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A winding mandrel and core rod for large cylindrical battery winding, characterized by, include: Core rod (1); A coiled needle (2) is inserted into a mandrel (1); Two diaphragms (3) are fixed together with the mandrel (1) by heat fusion during the pre-winding stage to form the initial winding base; The negative electrode (4) is inserted between two layers of diaphragm (3) and located at the crack position of the core rod (1); Positive electrode (5) is inserted into the gap between the separator (3) and the core rod (1).

2. The winding jig for a large cylindrical battery and the mandrel according to claim 1, wherein The core rod (1) is a tubular structure with an outer circle and an inner hexagon.

3. The winding jig for a large cylindrical battery and the mandrel according to claim 2, wherein The coiling needle (2) is a solid hexagonal rod, and the internal hexagonal hole of the core rod (1) is adapted to the outer contour of the coiling needle (2).

4. The winding jig for a large cylindrical battery and the mandrel according to claim 1, wherein It also includes a fixing device (7), which is fixed to the tail end of the winding needle (2) and is used to fix the relative position of the mandrel (1) and the winding needle (2) during the winding process.

5. The winding jig for a large cylindrical battery and the mandrel according to claim 1, wherein The coiling needle (2) is made of metal, which is one of tungsten steel, stainless steel or white steel.

6. The winding jig for a large cylindrical battery and the mandrel according to claim 1, wherein The diaphragm (3) is made of either polyethylene or polypropylene.

7. The winding jig for a large cylindrical battery and the mandrel according to claim 1, wherein The first end of the coiled needle (2) is connected to a top pin (6).

8. The winding jig for a large cylindrical battery and the mandrel according to claim 7, wherein The end face of the ejector pin (6) is provided with a slot for accommodating the head end of the coiling needle (2), and the slot is adapted to the head end of the coiling needle (2).

Images