A lithium battery cell winding structure and manufacturing process

Abstract

This invention discloses a lithium battery cell winding structure and manufacturing process, comprising several positive electrode plates, negative electrode plates, and separator paper. The main feature is that sealing elements extend from both ends of the separator paper. When the several positive electrode plates, negative electrode plates, and separator paper are wound together to form a cell, a seal is formed between the positive electrode blank ends of every two adjacent positive electrode plates and between the negative electrode blank ends of every two adjacent negative electrode plates. Therefore, if debris is generated when the ends of the cell are flattened, the sealing elements prevent the debris from falling and contacting the negative electrode plate, thus preventing a short circuit. Similarly, the sealing elements prevent the debris from falling and contacting the positive electrode plate, thus effectively solving the problem of short circuits caused by debris contact during the flattening of lithium battery cells. Combined with appropriate manufacturing processes, this better ensures product quality, improves product yield, and eliminates potential safety hazards in the use of lithium batteries.

Description

Technical Field

[0001] This invention relates to a manufacturing structure and method for a lithium battery cell, and more particularly to a winding structure and manufacturing process for a lithium battery cell. Background Technology

[0002] Currently, the main limitation of increasing the size of lithium batteries is the tab output process. However, with the development and maturation of the full-tab manufacturing process, it has become possible to increase the size of lithium batteries. The structure of a lithium battery cell mainly consists of several interleaved positive and negative electrode plates, and separator paper spaced between each pair of adjacent positive and negative electrode plates. Both sides of each positive and negative electrode plate are coated. Each positive electrode plate and each negative electrode plate has a positive blank end at the same end, and each negative electrode plate has a negative blank end at the same end. The positive and negative blank ends are arranged in opposite directions and are not coated on either side. Thus, a cell can be formed by simply winding several positive electrode plates, several negative electrode plates, and several spaced separator papers together. The positive and negative blank ends at both ends of the cell are then flattened to complete the manufacturing process. However, the above-mentioned kneading process will generate debris. The debris generated during the kneading of the positive electrode blank end can accidentally come into contact with the negative electrode when it falls, causing a short circuit. The debris generated during the kneading of the negative electrode blank end can also accidentally come into contact with the positive electrode when it falls, causing a short circuit. Therefore, this not only greatly affects the product quality and yield of lithium batteries, but also poses a safety hazard to the use of lithium batteries. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a lithium battery cell winding structure and manufacturing process that can effectively solve the problem of short circuit caused by debris contact during the rolling of lithium battery cells, ensure product quality, improve product yield, and eliminate safety hazards.

[0004] The technical problem of this invention is solved by the following technical solution:

[0005] A lithium battery cell winding structure includes several interleaved positive and negative electrode sheets. Each positive and negative electrode sheet is coated on both sides. A separator paper is provided between the coating layers of each two adjacent positive electrode sheets and the coating layers of the negative electrode sheets. Each positive electrode sheet and each negative electrode sheet has a negative electrode blank end at the same end. The positive and negative electrode blank ends are arranged in opposite directions and are not coated on either side. Each separator paper extends a sealing element from both ends. The several positive electrode sheets, several negative electrode sheets, and several spaced separator papers are wound together to form a battery cell. Each two adjacent positive electrode blank ends are sealed by the sealing element, and each two adjacent negative electrode blank ends are also sealed by the sealing element.

[0006] The sealing element is formed by extending from the end of the diaphragm paper and beyond the end of the coating layer, while not extending beyond the end of the positive electrode blank end or the end of the negative electrode blank end.

[0007] The diaphragm paper has two ends that extend into bent necks, which extend beyond the end of the coating layer and then extend into a sealing element.

[0008] The sealing element is formed by bending the end of the diaphragm paper. When forming the battery cell, an elastic seal is formed between each pair of adjacent positive electrode blank ends by the bending sealing element, and an elastic seal is also formed between each pair of adjacent negative electrode blank ends by the bending sealing element.

[0009] The sealing element is formed by the spiral-shaped bending of the extended end of the diaphragm paper.

[0010] The sealing element is formed by folding the end of the diaphragm paper. When forming the battery cell, an elastic seal is formed between each pair of adjacent positive electrode blank ends by compression through the folded sealing element, and an elastic seal is also formed between each pair of adjacent negative electrode blank ends by compression through the folded sealing element.

[0011] The sealing element is formed by repeatedly folding the extended end of the diaphragm paper in both directions or in the same direction.

[0012] The sealing element is a diaphragm paper with adhesive applied to both sides of its extended end. When forming a battery cell, each pair of adjacent positive electrode blank ends are bonded together by the adhesive-coated sealing element to form an elastic seal, and each pair of adjacent negative electrode blank ends are also bonded together by the adhesive-coated sealing element to form an elastic seal.

[0013] The sealing element is a membrane paper with tape on both sides of its extended end. When forming a battery cell, each pair of adjacent positive electrode blank ends are bonded together by the sealing element with tape to form an elastic seal, and each pair of adjacent negative electrode blank ends are also bonded together by the sealing element with tape to form an elastic seal.

[0014] A manufacturing process for a lithium battery cell winding structure includes the following steps:

[0015] Step 1: Select several positive electrode plates, negative electrode plates, and separator paper cut according to the winding size of the battery cell;

[0016] Step 2: Coat both sides of each positive electrode and each negative electrode with a coating layer, and leave a blank positive electrode end at one end of each positive electrode, meaning that the blank positive electrode end is not coated on either side; also leave a blank negative electrode end at one end of each negative electrode, meaning that the blank negative electrode end is not coated on either side.

[0017] Step 3: Extend sealing elements from both ends of each diaphragm paper. These sealing elements are mainly formed by bending or folding the extended ends of the diaphragm paper, or by applying adhesive or tape to both sides.

[0018] Step 4: Stack several positive electrode plates and several negative electrode plates in an alternating manner, and place a separator paper between the coating layers of each two adjacent positive electrode plates and the coating layers of the negative electrode plates in the alternating stack; and each separator paper used for separation must ensure that the sealing parts at both ends of the separator paper extend beyond the end of the coating layer, while not extending beyond the end of the blank end of the positive electrode or the end of the blank end of the negative electrode.

[0019] Step 5: After winding together the several positive electrode plates, several negative electrode plates and several spaced separator papers stacked in Step 4 to form a battery cell, the sealing element is used to seal between each pair of adjacent positive electrode blank ends, and also to seal between each pair of adjacent negative electrode blank ends.

[0020] Step Six: Flatten both ends of the battery cell that has been wound in Step Five, that is, flatten the positive and negative blank ends of the battery cell respectively. The debris generated by flattening the positive blank end is blocked by the seal and will not fall into the negative electrode and cause a short circuit. The debris generated by flattening the negative blank end is blocked by the seal and will not fall into the positive electrode and cause a short circuit.

[0021] Compared with the prior art, the present invention mainly extends sealing elements from both ends of the separator paper used to separate the coating layers of each two adjacent positive electrode plates and the coating layers of the negative electrode plates. When several positive electrode plates, several negative electrode plates and several spaced separator papers are wound together to form a battery cell, a seal can be formed between the positive electrode blank ends of each two adjacent positive electrode plates through the sealing elements, and a seal can also be formed between the negative electrode blank ends of each two adjacent negative electrode plates through the sealing elements. Therefore, when the blank ends of the positive and negative electrodes at both ends of the battery cell are flattened to generate debris, the debris generated from flattening the blank ends of the positive electrode is blocked by the seal and will not fall into contact with the negative electrode and cause a short circuit. Similarly, the debris generated from flattening the blank ends of the negative electrode is blocked by the seal and will not fall into contact with the positive electrode and cause a short circuit. This effectively solves the problem of debris contacting and causing short circuits when flattening lithium battery cells. Combined with appropriate manufacturing processes, this can better ensure product quality, improve product yield, and eliminate potential safety hazards in the use of lithium batteries. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the sealing element, which is formed by bending the end of the diaphragm paper extended from it.

[0023] Figure 2 This is a schematic diagram of the structure of the sealing element, which is formed by folding the end of the diaphragm paper extension.

[0024] Figure 3 This is a schematic diagram of the structure of the present invention, in which the sealing element is made of diaphragm paper with adhesive applied to both sides of the extended end.

[0025] Figure 4 This is a schematic diagram of the structure of the sealing element of the present invention, in which adhesive tape is provided on both sides of the end of the diaphragm paper extension. Detailed Implementation

[0026] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0027] like Figures 1-4 As shown, 1. Positive electrode, 11. Positive electrode blank end, 2. Negative electrode, 21. Negative electrode blank end, 3. Coating layer, 4. Separator paper, 41. Seal, 42. Neck.

[0028] A lithium battery cell winding structure and manufacturing process, such as Figures 1-4As shown, this refers specifically to the manufacturing structure and method of a cylindrical lithium battery cell. Its structure mainly consists of several positive electrode plates 1, several negative electrode plates 2, and several separator papers 4. Among them, several positive electrode plates 1 and several negative electrode plates 2 are stacked together in an alternating manner, while the separator papers 4 are spaced between each adjacent pair of positive electrode plates 1 and negative electrode plates 2. Therefore, the above structure is actually formed by stacking positive electrode plates 1, separator papers 4, and negative electrode plates 5 as a group, and then stacking multiple groups together.

[0029] Each positive electrode 1 and each negative electrode 2 is coated with a coating layer 3 on both sides. Therefore, the separator paper 4 is actually arranged at intervals between the coating layer 3 of each two adjacent positive electrode 1 and the coating layer 3 of the negative electrode 2.

[0030] At the same time, several positive electrode plates 1 are provided with a positive electrode blank end 11 at the same end, that is Figure 1 The views shown all have a positive electrode blank end 11 on the right; several negative electrode plates 2 all have a negative electrode blank end 21 on the same end, that is... Figure 1 The left end of the view shown is provided with a negative blank end 21; therefore, the positive blank end 11 and the negative blank end 21 are set in opposite directions, and neither side is coated with a coating layer 3.

[0031] In addition, each diaphragm paper 4 extends a sealing element 41 from both ends. Specifically, each end of the diaphragm paper 4 first extends a bent neck 42, which extends beyond the end of the coating layer 3 before extending the sealing element 41. That is to say, the sealing element is formed by extending from the end of the diaphragm paper 4 and extending beyond the end of the coating layer 3, while the sealing element 41 does not extend beyond the end of the positive electrode blank end 11 or the end of the negative electrode blank end 21.

[0032] In this way, a number of positive electrode plates 1, a number of negative electrode plates 2 and a number of spaced separator papers 4 can be wound together to form a battery cell, and a seal can be formed between each two adjacent positive electrode blank ends 11 through a sealing member 41, and a seal can also be formed between each two adjacent negative electrode blank ends 21 through a sealing member 41.

[0033] In this embodiment, the sealing element 41 is designed with four structures: the first type of sealing element 41 is formed by the snail-shaped bending of the end of the diaphragm paper 4. When forming the battery cell, the two adjacent positive electrode blank ends 11 are squeezed together by the bent sealing element 41 to form an elastic seal, and the two adjacent negative electrode blank ends 21 are also squeezed together by the bent sealing element 41 to form an elastic seal.

[0034] The second type of sealing element 41 is formed by repeatedly folding the end of the diaphragm paper 4 in both directions or by folding it sequentially in the same direction. When forming a battery cell, an elastic seal is formed between each two adjacent positive electrode blank ends 11 by the folded sealing element 41, and an elastic seal is also formed between each two adjacent negative electrode blank ends 21 by the folded sealing element 41.

[0035] The third type of sealing element is that the two sides of the extended end of the diaphragm paper 4 are coated with adhesive. When the battery cell is formed, each pair of adjacent positive electrode blank ends 11 are bonded together by the adhesive-coated sealing element 41 to form an elastic seal. Each pair of adjacent negative electrode blank ends 21 are also bonded together by the adhesive-coated sealing element 41 to form an elastic seal.

[0036] The fourth type of sealing element 41 has adhesive tape on both sides of the extended end of the diaphragm paper 4. When forming a battery cell, each pair of adjacent positive electrode blank ends 11 are bonded together by the sealing element 41 with adhesive tape to form an elastic seal. Each pair of adjacent negative electrode blank ends 21 are also bonded together by the sealing element 41 with adhesive tape to form an elastic seal.

[0037] Therefore, through the design of the above four types of sealing elements 41, when the positive electrode blank end 11 and the negative electrode blank end 21 at both ends of the battery cell are flattened and generate debris, the debris generated by flattening the positive electrode blank end 11 can be blocked by the sealing element 41 and will not fall into contact with the negative electrode plate 2 to cause a short circuit. The debris generated by flattening the negative electrode blank end 21 can be blocked by the sealing element 41 and will not fall into contact with the positive electrode plate 1 to cause a short circuit. This effectively solves the problem of debris contacting and causing a short circuit when the lithium battery cell is flattened.

[0038] Of course, if the seal 41 adopts the first type of bending or the second type of folding, the seal 41 itself will have elasticity. If the seal 41 adopts the third type of adhesive coating or the fourth type of tape, since the adhesive layer or tape also has a certain degree of elasticity, the seal 41 will also have elasticity when forming an adhesive seal. The main purpose of the seal 41 forming an elastic seal is to ensure that the internal pressure formed during the winding or electrolyte injection process of the lithium battery cell can be released through the elastic contact seal 41, while not affecting the seal 41's sealing of the tab debris.

[0039] Combining this lithium battery cell winding structure with corresponding manufacturing processes can better ensure product quality, improve product yield, and eliminate potential safety hazards in the use of lithium batteries.

[0040] The manufacturing process of the lithium battery cell winding structure mainly includes the following steps:

[0041] Step 1: Select several positive electrode plates 1, negative electrode plates 2, and separator paper 4, which are cut according to the winding size of the battery cell.

[0042] Step 2: Coat both sides of each positive electrode 1 and each negative electrode 2 with coating layer 3, and leave a blank positive electrode end 11 at one end of each positive electrode 1, that is, the blank positive electrode end 11 is not coated with coating layer 3 on both sides; and leave a blank negative electrode end 21 at one end of each negative electrode 2, that is, the blank negative electrode end 21 is not coated with coating layer 3 on both sides.

[0043] Step 3: Extend sealing elements 41 from both ends of each diaphragm paper 4. The sealing elements are mainly formed by bending or folding the extended ends of the diaphragm paper 4, or by applying glue or tape to both sides.

[0044] Step 4: Several positive electrode plates 1 and several negative electrode plates 2 are stacked in an alternating manner, and a separator paper 4 is provided between each two adjacent positive electrode plate 1 coating layer 3 and negative electrode plate 2 coating layer 3 in the alternating stack; and each separator paper 4 used for separation needs to ensure that the sealing parts 41 at both ends of the separator paper extend beyond the end of the coating layer 3, while not extending beyond the end of the positive electrode blank end 11 or the end of the negative electrode blank end 21.

[0045] Step 5: After winding together the several positive electrode plates 1, several negative electrode plates 2 and several spaced separator papers 4 as arranged in Step 4 to form a battery cell, the sealing element 41 is used to seal between each pair of adjacent positive electrode blank ends 11 and between each pair of adjacent negative electrode blank ends 21.

[0046] Step 6: Flatten both ends of the battery cell that has been wound in Step 5, that is, flatten the positive electrode blank end 11 and the negative electrode blank end 21 at both ends of the battery cell. The debris generated by flattening the positive electrode blank end 11 is blocked by the sealing element 41 and will not fall into contact with the negative electrode plate 2 to cause a short circuit. The debris generated by flattening the negative electrode blank end 21 is blocked by the sealing element 41 and will not fall into contact with the positive electrode plate 1 to cause a short circuit.

[0047] The above description is merely a specific embodiment of the present invention. Those skilled in the art should understand that any structural design similar to this embodiment should be included within the protection scope of the present invention.

Claims

1. A manufacturing process for a winding structure of a lithium battery cell, wherein the lithium battery cell comprises a plurality of interleaved positive electrode plates (1) and negative electrode plates (2), each positive electrode plate (1) and each negative electrode plate (2) having a coating layer (3) on both sides, a separator paper (4) being provided between each pair of adjacent positive electrode plates (1) coating layer (3) and negative electrode plate (2) coating layer (3), a positive electrode blank end (11) being provided at the same end of the plurality of positive electrode plates (1), and a negative electrode blank end (21) being provided at the same end of the plurality of negative electrode plates (2), wherein the positive electrode blank end (11) and the negative electrode blank end (21) are arranged in opposite directions and neither side is coated with a coating layer (3), characterized in that, Each of the diaphragm paper (4) extends a sealing element (41) from both ends. The sealing element (41) is formed by bending or folding the extended end of the diaphragm paper (4), or by applying glue or tape on both sides. The plurality of positive electrode plates (1), the plurality of negative electrode plates (2) and the plurality of spaced diaphragm papers (4) are wound together to form a battery cell, and an elastic seal is formed between each two adjacent positive electrode blank ends (11) by the compression or bonding of the sealing element (41). An elastic seal is also formed between each two adjacent negative electrode blank ends (21) by the compression or bonding of the sealing element (41). The manufacturing process includes the following steps: Step 1: Select several positive electrode plates (1), negative electrode plates (2), and separator paper (4) cut according to the winding size of the battery cell. Step 2: Coat both sides of each positive electrode (1) and each negative electrode (2) with a coating layer (3), and leave a blank positive electrode end (11) at one end of each positive electrode (1), that is, the blank positive electrode end (11) is not coated with a coating layer (3) on both sides; leave a blank negative electrode end (21) at one end of each negative electrode (2), that is, the blank negative electrode end (21) is not coated with a coating layer (3) on both sides. Step 3: Extend sealing elements (41) from both ends of each diaphragm paper (4). The sealing elements are formed by bending or folding the extended ends of the diaphragm paper (4), or by applying glue or tape to both sides. Step 4: Several positive electrode plates (1) and several negative electrode plates (2) are stacked in an alternating manner, and a separator paper (4) is provided between the coating layer (3) of each two adjacent positive electrode plates (1) and the coating layer (3) of the negative electrode plate (2) for spacing; and each separator paper (4) used for spacing needs to ensure that the sealing elements (41) at both ends of the separator paper extend beyond the end of the coating layer (3), while not extending beyond the end of the positive electrode blank end (11) or the end of the negative electrode blank end (21); Step 5: After winding together the several positive electrode plates (1), several negative electrode plates (2) and several spaced separator papers (4) stacked in step 4 to form a battery cell, the sealing element (41) is used to seal between each pair of adjacent positive electrode blank ends (11) and also to seal between each pair of adjacent negative electrode blank ends (21). Step 6: Flatten both ends of the battery cell that has been wound in Step 5, that is, flatten the positive blank end (11) and the negative blank end (21) at both ends of the battery cell. The debris generated by flattening the positive blank end (11) is blocked by the sealing element (41) and will not fall to contact the negative electrode plate (2) to cause a short circuit. The debris generated by flattening the negative blank end (21) is blocked by the sealing element (41) and will not fall to contact the positive electrode plate (1) to cause a short circuit.

2. The manufacturing process of a lithium battery cell winding structure according to claim 1, characterized in that... The diaphragm paper (4) has two ends that first extend into bent necks (42), which extend beyond the end of the coating layer (3) and then extend into a seal (41).

3. The manufacturing process of a lithium battery cell winding structure according to claim 1, characterized in that... The sealing element (41) is formed by the snail-shaped bend of the extended end of the diaphragm paper (4).

4. The manufacturing process of a lithium battery cell winding structure according to claim 1, characterized in that... The sealing element (41) is formed by repeatedly folding the extended end of the diaphragm paper (4) in both directions or by folding it sequentially in the same direction.

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