阅读说明：本技术 用于防止二次电池的隔板弯曲的隔板密封设备和方法 (Separator sealing apparatus and method for preventing bending of separator of secondary battery ) 是由 李敏宰 金鍾勳 黄成敏 于 2020-04-14 设计创作，主要内容包括：公开了一种用于将中间插入有电极板的上隔板和下隔板结合的隔板密封设备,并且所述隔板密封设备包括：第一密封单元,所述第一密封单元被配置为密封第一区域,所述第一区域被指定为在上隔板和下隔板彼此面对的部分之中、沿着电极板的宽度方向的外边缘；和第二密封单元,所述第二密封单元被配置为密封第二区域,所述第二区域被指定为在上隔板和下隔板彼此面对的部分之中、沿着电极板的长度方向的外边缘。(Disclosed is a separator sealing apparatus for coupling an upper separator and a lower separator with an electrode plate interposed therebetween, and the separator sealing apparatus includes: a first sealing unit configured to seal a first region designated as an outer edge in a width direction of the electrode plate among portions where the upper and lower separators face each other; and a second sealing unit configured to seal a second region designated as an outer edge along a length direction of the electrode plate among portions where the upper and lower separators face each other.)

1. A separator sealing apparatus for coupling an upper separator and a lower separator with an electrode plate interposed therebetween, comprising:

a first sealing unit configured to seal a first region designated as an outer edge in a width direction of the electrode plate among portions where the upper separator and the lower separator face each other; and

a second sealing unit configured to seal a second region designated as an outer edge along a length direction of the electrode plate among portions where the upper and lower separators face each other.

2. The diaphragm seal apparatus of claim 1, further comprising:

a transfer unit configured to continuously supply the electrode plate, the upper separator, and the lower separator in one direction,

wherein the first sealing unit and the second sealing unit operate to move vertically in synchronization with the transfer unit at a preset speed and are configured to press and thermally fuse the first region and the second region.

3. The bulkhead sealing apparatus of claim 1,

wherein the second sealing unit is configured to be assembled with the first sealing unit and reassembled with the first sealing unit according to the width of the electrode plate.

4. The bulkhead sealing apparatus of claim 1,

wherein the first sealing unit includes:

a first upper heating block configured to apply pressure and heat to the first region of the upper partition; and

a first lower heating block disposed vertically symmetrical to the first upper heating block and configured to apply pressure and heat to the first region of the lower partition plate.

5. The bulkhead sealing apparatus of claim 4,

wherein the first upper heating blocks are arranged in pairs,

a pair of first upper heating blocks are spaced apart from each other at a predetermined interval to extend side by side in one direction,

the first lower heating blocks are arranged in pairs, and

the pair of first lower heating blocks is disposed to be vertically symmetrical to the pair of first upper heating blocks.

6. The bulkhead sealing apparatus of claim 5,

wherein the second sealing unit includes:

a plurality of second upper heating blocks respectively configured to extend in a direction intersecting the first upper heating blocks and be coupled to the pair of first upper heating blocks at positions spaced apart from each other at predetermined intervals along an extending direction of the pair of first upper heating blocks to apply heat and pressure to the second region of the upper partition plate; and

a plurality of second lower heating blocks disposed symmetrically to the second upper heating block in a one-to-one relationship and coupled to the pair of first lower heating blocks to apply heat and pressure to the second region of the lower partition plate.

7. The bulkhead sealing apparatus of claim 6,

wherein the pair of first upper heating blocks has a plurality of grooves formed at predetermined intervals along the extending direction,

each of the second upper heating blocks has a connection portion having a step formed in at least one end thereof, and

the connecting portion is selectively fitted into one of the plurality of grooves.

8. The bulkhead sealing apparatus of claim 7,

wherein the connection portions are fixed and released in the grooves of the pair of first upper heating blocks by bolts.

9. A separator sealing method for sealing an upper separator and a lower separator using the separator sealing apparatus according to claim 1, the separator sealing method comprising:

both the first region and the second region are sealed such that the electrode plate is not exposed to the outside.

10. The separator sealing method according to claim 9,

wherein the separator sealing method is used for sealing a semi-finished product of a single cell in which a lower separator, a negative electrode plate, an upper separator and a positive electrode plate are sequentially stacked, or for sealing a semi-finished product of a single cell in which a lower separator, a negative electrode and an upper separator are sequentially stacked.

Technical Field

The present disclosure relates to a sealing apparatus and method for a separator of a secondary battery, and more particularly, to a sealing apparatus and method thereof that are installed on a production line of a single cell semi-finished product or a semi-finished product of a semi-cell to seal the separator so as to prevent the separator from being bent.

The present application claims priority from korean patent application No. 10-2019-0088483, filed in korea at 22.7.7.2019, the disclosure of which is incorporated herein by reference.

Background

Recently, the demand for secondary batteries as an environmentally friendly energy source is rapidly increasing. Among secondary batteries, lithium secondary batteries having high energy density, high operating potential, long cycle life and low self-discharge rate have been commercialized and widely used.

The lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate, to which a positive active material and a negative active material are respectively applied, are interposed with a separator, and a case (i.e., a battery case) in which the electrode assembly is hermetically received together with an electrolyte.

An electrode assembly of a lithium secondary battery having a cathode/separator/anode structure may be briefly classified into a roll type (winding type), a stack type, and a stack/folding type as a mixture of the winding type and the stack type.

The jelly-roll type electrode assembly was prepared by: a metal foil used as a current collector is coated with an electrode active material or the like, dried and pressed, and then cut into a band shape having a desired width and length, and a negative electrode and a positive electrode are separated using a separator and then wound into a spiral shape. The jelly-roll type electrode assembly is suitable for a cylindrical battery.

The stacking or stacking/folding type electrode assembly has a structure in which a cathode unit and an anode unit are sequentially stacked with a separator interposed therebetween, and a rectangular shape can be easily obtained.

The stacked or stacked/folded lithium secondary battery may be obtained by: the unit cells (mono cells) 110 having the structure of the positive electrode plates 104/the upper separator 101/the negative electrode plates 103/the lower separator 102 as shown in fig. 1 are repeatedly stacked, or the unit cells 110 are folded using a continuous separator, or the positive electrode plates are added to the upper or lower portion of the half cells (half cells) 120 having the structure of the upper separator 101/the negative electrode plates 103/the lower separator 102.

Meanwhile, in the stacked or stacked/folded lithium secondary battery, a low-voltage defective battery in which the secondary battery exhibits a voltage drop behavior higher than a self-discharge rate is sometimes found. In this case, if the edge of the separator is folded or torn during the assembly process, the positive and negative electrodes may directly face each other, which is a main cause of an electrical short circuit. For this reason, as shown in fig. 2, as a prior art, a method of preventing the separator folding phenomenon by bonding the edges S of the upper and lower separators 101 and 102 in the width direction of the battery semi-finished product has been proposed.

However, the external exposure of the electrode between the upper and lower separators 101 and 102 cannot be fundamentally prevented merely by sealing the edges of the battery semi-finished product only in the width direction. Therefore, a method of further improving the low voltage defect rate by additionally bonding the edges of the upper and lower separators 101 and 102 in the length direction of the battery semi-finished product to fundamentally prevent the exposure of the electrodes is being discussed.

Disclosure of Invention

Technical problem

The present disclosure is designed to solve the problems of the prior art, and therefore, the present disclosure aims to provide a sealing apparatus and method which can be easily applied to an existing battery semi-finished product production line and can fundamentally prevent electrodes from being exposed from the battery semi-finished product by bonding all edge lines of upper and lower separators in width and length directions.

Technical scheme

In one aspect of the present disclosure, there is provided a separator sealing apparatus for coupling an upper separator and a lower separator with an electrode plate interposed therebetween, the separator sealing apparatus comprising:

a first sealing unit configured to seal a first region designated as an outer edge in a width direction of the electrode plate among portions where the upper and lower separators face each other; and a second sealing unit configured to seal a second region designated as an outer edge along a length direction of the electrode plate among portions where the upper and lower separators face each other.

The separator sealing apparatus may further include a transfer unit configured to continuously supply the electrode plate, the upper separator, and the lower separator in one direction, and the first sealing unit and the second sealing unit operate in synchronization with the transfer unit at a preset speed to vertically move and configured to press and thermally fuse the first region and the second region.

The second sealing unit may be configured to be assembled with the first sealing unit and reassembled with the first sealing unit according to the width of the electrode plate.

The first sealing unit may include: a first upper heating block configured to apply pressure and heat to a first region of the upper partition; and a first lower heating block disposed to be vertically symmetrical to the first upper heating block and configured to apply pressure and heat to the first region of the lower partition plate.

The first upper heating blocks may be disposed in pairs, a pair of the first upper heating blocks may be spaced apart from each other at a predetermined interval to extend side by side in one direction, the first lower heating blocks may be disposed in pairs, and a pair of the first lower heating blocks may be disposed to be vertically symmetrical to the pair of the first upper heating blocks.

The second sealing unit may include: a plurality of second upper heating blocks respectively configured to extend in a direction intersecting the first upper heating blocks and be coupled to a pair of the first upper heating blocks at positions spaced apart from each other at predetermined intervals along an extending direction of the pair of the first upper heating blocks to apply heat and pressure to a second region of the upper partition plate; and a plurality of second lower heating blocks disposed to be symmetrical to the second upper heating blocks in a one-to-one relationship and coupled to the pair of first lower heating blocks to apply heat and pressure to the second region of the lower barrier.

The pair of first upper heating blocks may have a plurality of grooves formed at predetermined intervals along the extending direction, each of the second upper heating blocks may have a connection portion formed in at least one end thereof with a step, and the connection portion may be selectively fitted into one of the plurality of grooves.

The connection portions may be fixed and released in the grooves of the pair of first upper heating blocks by bolts.

In another aspect of the present disclosure, there is also provided a separator sealing method for sealing an upper separator and a lower separator using the above separator sealing apparatus, the separator sealing method including:

both the first region and the second region are sealed such that the electrode plate is not exposed to the outside.

The separator sealing method may be used for sealing a semi-finished product of a single cell in which a lower separator, a negative electrode plate, an upper separator, and a positive electrode plate are sequentially stacked, or for sealing a semi-finished product of a single cell in which a lower separator, a negative electrode, and an upper separator are sequentially stacked.

Advantageous effects

According to the embodiments of the present disclosure, the low voltage defect rate may be significantly reduced by preventing the electrode from being exposed to the outside of the battery semi-finished product.

According to another embodiment of the present disclosure, it is possible to continuously mass-produce battery semi-finished products by synchronizing with the speed of an existing semi-finished product production line.

Drawings

Fig. 1 is a sectional view of a battery semi-finished product, schematically showing a conventional single cell semi-finished product and a stack structure of the semi-finished product.

Fig. 2 is a plan view showing a conventional battery semi-finished product.

Fig. 3 and 4 are views for illustrating a process of sealing a separator of a battery semi-finished product by using a separator sealing apparatus according to an embodiment of the present disclosure.

Fig. 5 is a plan view showing the battery semi-finished product of fig. 4 after final cutting.

Fig. 6 is a diagram schematically illustrating a first sealing unit and a second sealing unit according to an embodiment of the present disclosure.

Fig. 7 is a plan view illustrating the first and second upper heating blocks of fig. 6 assembled together.

Fig. 8 is a sectional view schematically showing a connection portion of the first upper heating block and the second upper heating block of fig. 7.

Detailed Description

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only preferred embodiments of the present disclosure, and do not represent all the technical features of the present disclosure. Furthermore, to assist in understanding the disclosure, the drawings are not to scale, but the dimensions of some of the elements may be exaggerated.

The separator sealing apparatus according to the present disclosure includes a first sealing unit 10, a second sealing unit 20, and a transfer unit 30, and as shown in fig. 3 and 4, a process of bonding an upper separator 101 and a lower separator 102 in a battery cell may be performed before finally cutting a continuously supplied semi-finished product (see fig. 1).

Here, the battery semi-finished product refers to a battery semi-finished product before final cutting. The battery semi-finished product before final cutting may include: a lower separator 102 in the form of a continuous film; a negative electrode plate 103 having a certain width and disposed on the lower separator 102 to be spaced apart from each other; and an upper separator 101 disposed on the negative electrode plate 103 in the form of a continuous film, or may include positive electrode plates 104 disposed on the upper separator 101 to be spaced apart from each other with a predetermined width.

Before the final cutting, the battery semi-finished products, i.e., the unit cell semi-finished products or the semi-finished products, may be continuously supplied in one direction by the transfer unit 30, and the predetermined separator portions D1, D2 may be sealed by the first and second sealing units 10, 20. The first sealing unit 10 and the second sealing unit 20 may be operated in synchronization with the transfer unit 30 at a preset speed.

For example, if some of the semi-finished battery products before cutting reach the position for the separator sealing process, the transfer unit 30 stops operating for a certain period of time. At this time, the first and second sealing units 10 and 20 may be operated (vertically moved) to press and thermally fuse the barrier portions D1, D2 to be sealed for a certain period of time. Then, the battery pressing operation of the first sealing unit 10 and the second sealing unit 20 is released, and the transfer unit 30 is operated again to move the battery semi-finished product before cutting. Thereafter, the separator is cut using a cutter (not shown) to complete the final unit cell semi-finished product or the final half cell semi-finished product.

Hereinafter, the configuration of the first sealing unit 10 and the second sealing unit 20 will be described in more detail with reference to fig. 6 to 8.

The first sealing unit 10 and the second sealing unit 20 are means for bonding two separators (i.e., an upper separator 101 and a lower separator 102) of a battery semi-finished product to each other by applying heat and pressure. Here, the first sealing unit 10 may be configured to apply heat and pressure to the first region D1, and the second sealing unit 20 may be configured to apply heat and pressure to the second region D2. The first sealing unit 10 and the second sealing unit 20 may be implemented using, for example, a heating block having heating wires therein.

Here, the first region D1 (see fig. 5) refers to outer edges along the width direction of the electrode plate, i.e., outer regions of both short sides of the electrode plate, among the portions where the upper and lower separators 101 and 102 face each other, and the second region D2 refers to outer edges along the length direction of the electrode plate, i.e., outer regions of both long sides of the electrode plate, among the portions where the upper and lower separators 101 and 102 face each other.

As shown in fig. 6, the first sealing unit 10 according to the embodiment may include first upper heating blocks 11, 12 and first lower heating blocks 13, 14.

The two first upper heating blocks 11, 12 are provided in pairs, and the pair of first upper heating blocks 11, 12 are provided to be spaced apart from each other by the length of the battery semi-finished product (Y-axis direction) and extend side by side in one direction (X-axis direction). In this embodiment, the first upper heating blocks 11, 12 extend approximately corresponding to the width of the three unit cell semi-finished products before cutting. Here, the extension length may be configured to be longer or shorter than this embodiment.

The first lower heating blocks 13, 14 are disposed vertically symmetrically to the first upper heating blocks 11, 12. That is, the two first lower heating blocks 13, 14 are also provided in pairs, and the pair of first lower heating blocks 13, 14 may be provided to be symmetrical to the pair of first upper heating blocks 11, 12.

As described above, the first sealing unit 10 including the pair of first upper heating blocks 11, 12 and the pair of first lower heating blocks 13, 14 may be in contact with and operated to apply heat and pressure to the upper and lower portions of the first regions D1 of the two separators of the plurality of battery semi-finished products.

That is, the first region D1 of the upper separator 101 of the plurality of semi-finished batteries may be pressed downward together by the first upper heating blocks 11, 12, while the first region D1 of the lower separator 102 may also be pressed upward together by the first lower heating blocks 13, 14. At this time, the first region D1 of the upper separator 101 and the first region D1 of the lower separator 102 may contact each other and be fused to each other by heating.

Further, the second sealing unit 20 is a means for sealing the second region D2 of the upper and lower partition plates 101 and 102 facing each other, which cannot be sealed by the first sealing unit 10, and includes a plurality of second upper heating blocks 21 and a plurality of second lower heating blocks 23.

The second upper heating blocks 21 extend in a direction (Y-axis direction) intersecting the pair of first upper heating blocks 11, 12, respectively, and may be coupled to the pair of first upper heating blocks 11, 12 at positions spaced apart at predetermined intervals along the extending direction of the pair of first upper heating blocks 11, 12.

The second lower heating block 23 is disposed to be vertically symmetrical to the second upper heating block 21. In other words, the second lower heating block 23 is vertically symmetrical to the second upper heating block 21 in a one-to-one relationship, and is disposed to be coupled to the pair of first lower heating blocks 13, 14, respectively.

The second upper and lower heating blocks 21 and 23 are heating blocks corresponding to the second region D2 of the battery semi-finished product, and press the battery semi-finished product like the first sealing unit 10 to apply heat and pressure to the second regions D2 of the two separators.

More specifically, the second regions D2 of the upper separators 101 of the plurality of semi-finished batteries may be pressed downward together by the second upper heating block 21, while the second regions D2 of the lower separators 102 may be pressed upward together by the second lower heating block 23. At this time, the second region D2 of the upper separator 101 and the second region D2 of the lower separator 102 may contact each other and be fused to each other by heating.

According to the separator sealing apparatus having the above configuration and operation, after the final cutting, since the first and second regions D1 and D2 of the upper and lower separators 101 and 102, that is, the outer regions of the upper and lower separators 101 and 102 facing each other in the width and length directions of the electrode plates, are completely combined, it is possible to prepare a battery semi-finished product that fundamentally prevents the electrode plates (negative electrode plates) from being exposed to the outside. If the stacked or stacked/folded type lithium secondary battery is assembled using the battery semi-finished product 110, the low voltage defect rate of the lithium secondary battery can be significantly reduced as compared to the related art.

Further, the final battery semi-finished products 110 can be continuously mass-produced by sealing the separators of the plurality of battery semi-finished products while continuously moving the battery semi-finished products before cutting in the production line direction in synchronization with the speed of the conveying unit 30.

Meanwhile, the first sealing unit 10 and the second sealing unit 20 according to the embodiment of the present disclosure may be provided to be assembled and disassembled with each other. Hereinafter, the assembling and disassembling configuration of the first sealing unit 10 and the second sealing unit 20 will be described.

The assembling and disassembling configuration of the first upper heating blocks 11, 12 and the second upper heating block 21 is the same as that of the first lower heating blocks 13, 14 and the second lower heating block 23. Therefore, the assembling and disassembling configurations of the first lower heating blocks 13, 14 and the second lower heating block 23 will not be described in detail.

As shown in fig. 7 and 8, the pair of first upper heating blocks 11, 12 has a plurality of grooves H formed at regular intervals along the extending direction. The second upper heating block 21 may be coupled to the pair of first upper heating blocks 11, 12 by selecting one of the plurality of grooves H and fitting the ends of the second upper heating block 21 into the corresponding grooves H.

More specifically, the second upper heating block 21 may have connection portions 21a formed at both ends thereof with steps, and the connection portions 21a may be placed in the grooves H of the first upper heating blocks 11, 12 in an assembled manner, and may be fixed to and released from the grooves H by bolts B. Although not shown in the drawings, holes formed with threads may be provided in the connection portion 21a and the grooves H of the first upper heating blocks 11, 12 so that the bolts B may be vertically fastened.

According to the above configuration, the interval between the second upper heating blocks 21 may be adjusted, or the number of the second upper heating blocks 21 may be further increased or decreased, so that it is possible to seal the separators of various battery semi-finished products having different widths by using one separator sealing apparatus.

Further, if some of the heating blocks in the diaphragm sealing apparatus are damaged, the diaphragm sealing apparatus can be normally used by replacing only the corresponding heating blocks. Therefore, it may be effective in management and maintenance of the diaphragm sealing apparatus.

Subsequently, a method of sealing the separator of the battery semi-finished product using the above-described separator sealing apparatus will be briefly summarized as follows.

Referring again to fig. 3 and 4, the battery semi-finished products before cutting may be continuously supplied in the production line direction (X-axis direction) by the transfer unit 30. The battery semi-finished product before cutting may be a single cell semi-finished product in which the lower separator 102, the negative electrode plate 103, the upper separator 101, and the positive electrode plate 104 are sequentially stacked, or a semi-battery semi-finished product in which the lower separator 102, the negative electrode, and the upper separator 101 are sequentially stacked.

The first sealing unit 10 and the second sealing unit 20 may be disposed at one side of the battery semi-finished product manufacturing line as described above, and may be operated in synchronization with the transfer unit 30. As shown in fig. 4, if three battery semi-finished products reach the sealing process region by the transfer unit 30, the first and second sealing units 10 and 20 are integrally operated in the vertical direction to press and thermally fuse the first and second regions D1 and D2 of each battery semi-finished product for a preset time. If the preset time has elapsed, the first sealing unit 10 and the second sealing unit 20 are returned to the original positions, and the next three semi-finished batteries in the unsealed state are placed in the sealing process area by the transfer unit 30. After the above-described sealing process, the battery semi-finished products may be cut one by one (cutting) using a cutter (not shown) while moving the battery semi-finished products along the manufacturing line to be prepared in the form of final unit battery semi-finished products.

As described above, the separator folding problem can be solved by implementing the separator sealing apparatus and the separator sealing method of the present disclosure, and various single cell semi-finished products or semi-finished products having different widths can be mass-produced on the same production line.

The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the scope of the disclosure will become apparent to those skilled in the art from this detailed description.

Meanwhile, even though terms indicating directions such as "upper", "lower", "left", and "right" are used in the specification, it is apparent to those skilled in the art that they are just for convenience of description and may be expressed differently according to the position of an observer or an object.