Electrode forming device

Abstract

The present invention relates to an electrode forming device which can form a pattern on an electrode to prevent the problem of lithium precipitation caused by lithium intercalation and deintercalation into and from the electrode not occurring smoothly during rapid charging, and makes it possible to manufacture and use a customized forming unit according to the situation without manufacturing an entire forming roll in relation to the fact that pattern conditions may vary according to the length and position of the electrode.

Description

Electrode forming device

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0182571 filed on December 10, 2024, and all contents disclosed in the document of said Korean Patent Application are incorporated herein as part of this specification.

[0003] Technology field

[0004] The present invention relates to an electrode forming device, wherein a pattern can be formed on an electrode to prevent the problem of lithium precipitation caused by the inability of lithium insertion and extraction from the electrode during rapid charging, and wherein, in relation to the fact that pattern conditions may vary depending on the length and position of the electrode, a customized forming part can be manufactured and used according to the situation without manufacturing the entire forming roll.

[0005] Secondary batteries are classified according to the shape of the battery case into cylindrical and prismatic batteries, in which the electrode assembly is embedded in a cylindrical or prismatic metal can, and pouch-type batteries, in which the electrode assembly is embedded in a pouch-type case made of aluminum laminate sheets.

[0006] In addition, the electrode assembly embedded in the battery case is a power generation element capable of charging and discharging, comprising a stacked structure of a positive electrode, a separator, and a negative electrode, and can be classified into a jellyroll-type structure in which a separator is interposed between long sheet-type positive and negative electrodes coated with an active material and wound, a stack-type structure in which a plurality of positive and negative electrodes of a predetermined size are sequentially stacked with a separator interposed, and a stack / folding-type electrode assembly in which bicells or full cells are wound by stacking positive and negative electrodes of a predetermined unit with a separator interposed.

[0007] Among them, jelly-roll type electrode assemblies are widely produced due to their advantages of ease of manufacturing and high energy density per unit weight. A jelly-roll type electrode assembly could be manufactured by assembling a laminate comprising long sheet-type positive and negative electrodes with a separator interposed between them, and then winding the sheet along its length while a winding core is in contact with one end of the electrode laminate. Furthermore, this jelly-roll type electrode assembly can be inserted into a battery case made of a cylindrical metal can to form a cylindrical secondary battery.

[0008] Conventionally, in cylindrical secondary batteries, the presence of an outer rigid battery case (typically made of a can) caused stress due to the expansion of the jellyroll-type electrode assembly during charging. This stress resulted in a shortage of electrolyte in the affected areas, which led to an increase in resistance and consequently caused lithium (Li) precipitation. Particularly during rapid charging, the insertion and extraction of lithium did not occur smoothly, leading to uneven reactions on the surface and resulting in lithium precipitation problems.

[0009] When lithium precipitation occurs, the electrode thickness increases, leading to further compressive stress. This strongly compresses the porous separator, causing the lithium precipitation area to gradually expand. In this case, abnormal heat generation behavior may be exhibited, and the risk of ignition increases significantly. The pores of the separator become clogged due to compressive stress, and a rapid increase in resistance and heat generation occur due to the influence of the electrode byproduct layer. These continuous side reactions and lithium precipitation cause the jelly-roll type electrode assembly to expand, which was the cause of battery case rupture and even explosion. Therefore, research was required to solve these problems.

[0010] Accordingly, as part of a solution to these problems, a method for forming indented groove-shaped patterns on the electrode's retaining portion (the part coated with the electrode active material) has been researched and developed. For example, a forming roll with protrusions formed on a roll-shaped mold can be used. By rolling the electrode retaining portion while applying pressure with such a forming roll, multiple groove-shaped patterns can be formed on the electrode. However, since pattern conditions may vary depending on the length and position of the electrode, there was a problem in that after making one forming roll suitable for a given condition, the entire roll could not be reused and had to be newly manufactured when a different pattern shape was required.

[0011] The present invention has been devised to solve the above-mentioned problems. The objective of the present invention is to provide an electrode forming device that can form a pattern on an electrode to prevent the problem of lithium precipitation caused by the failure of lithium insertion and extraction from the electrode during rapid charging, and to enable the use of a customized forming section tailored to the situation without manufacturing an entire forming roll, in relation to the fact that pattern conditions may vary depending on the length and position of the electrode.

[0012] The electrode forming apparatus according to the present invention relates to an electrode forming apparatus for forming an electrode comprising a retaining portion coated with an electrode active material, wherein the apparatus comprises a roller unit having the shape of a roller and forming the retaining portion, and the roller unit comprises a body portion; and a forming portion including a projection that is detachably coupled to the outer surface of the body portion and forms the retaining portion.

[0013] The molding section is provided in multiple units, and the multiple molding sections can be formed spaced apart from each other.

[0014] The protrusions formed on multiple molded parts can all be provided in the same shape.

[0015] The body portion has a cylindrical shape, and the molding portion may include a first molding portion including a first projection; and a second molding portion including a second projection, positioned at a first interval (d1) in a direction parallel to the central axis (X) of the body portion.

[0016] The first protrusion and the second protrusion can have different sizes.

[0017] The molding part may further include a third molding part including a third projection, which is positioned at a distance of a second interval (d2) from the second molding part in a direction parallel to the central axis (X) of the body part.

[0018] The third projection may have a different size from at least one of the first projection and the second projection.

[0019] The molding part may include a protrusion forming area, which is an area where a protrusion is formed, and a protrusion non-forming area, which is an area where a protrusion is not formed.

[0020] The molding section is provided in multiple units, and the multiple molding sections can be formed in succession to each other.

[0021] The above body part has a cylindrical shape, and the protrusions included in the plurality of molded parts are all of the same shape, and the length of the protrusion-forming regions measured in a direction parallel to the central axis (X) of the body part is the same in all of the plurality of molded parts, and the length of the protrusion-non-forming regions measured in a direction parallel to the central axis (X) of the body part may also be the same in all of the plurality of molded parts.

[0022] The body portion has a cylindrical shape, and the molding portion may include a first molding portion including a first projection; and a second molding portion including a second projection located consecutively in a direction parallel to the central axis (X) of the body portion.

[0023] The first protrusion and the second protrusion can have different sizes.

[0024] The molding section may further include a third molding section that is located consecutively from the second molding section in a direction parallel to the central axis (X) of the body section and includes a third projection.

[0025] The third projection may have a different size from at least one of the first projection and the second projection.

[0026] The length of the protrusion-forming area measured in the direction of the central axis (X) of the body part is different from at least two of the first molding part, the second molding part, and the third molding part, and the length of the non-protrusion-forming area measured in the direction of the central axis (X) of the body part may also be different from at least two of the first molding part, the second molding part, and the third molding part.

[0027] The electrode forming device according to the present invention can form a pattern on the electrode to prevent the problem of lithium precipitation caused by the failure of lithium insertion and extraction from the electrode during rapid charging, and has the effect of being able to manufacture and use a customized forming part according to the situation without manufacturing the entire forming roll, in relation to the fact that pattern conditions may vary depending on the length and position of the electrode.

[0028] FIG. 1 is a perspective view illustrating an electrode forming apparatus according to Example 1 of the present invention.

[0029] FIG. 2 is a perspective view illustrating an electrode forming apparatus according to Example 2 of the present invention.

[0030] Hereinafter, preferred embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited or restricted by the following embodiments.

[0031] In order to clearly explain the present invention, detailed descriptions of related prior art that are irrelevant to the explanation or that may unnecessarily obscure the essence of the invention have been omitted. Furthermore, when assigning reference numerals to the components of each drawing in this specification, identical or similar reference numerals are assigned to identical or similar components throughout the entire specification.

[0032] Furthermore, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0033]

[0034] Example 1

[0035] FIG. 1 is a perspective view illustrating an electrode forming apparatus according to Example 1 of the present invention.

[0036] Referring to FIG. 1, the electrode forming apparatus (10) according to Embodiment 1 of the present invention is an electrode forming apparatus (10) that forms an electrode including a retaining portion coated with an electrode active material, and includes a roller unit (100). The roller unit (100) may refer to a forming unit having a roller shape. The roller unit (100) may be configured to form the retaining portion of the electrode having a roller shape. The retaining portion may refer to a portion on the electrode current collector on which the electrode active material is coated. For reference, the uncoated portion contrasting with the retaining portion may refer to a portion on the electrode current collector on which the electrode active material is not coated.

[0037] Here, the roller unit (100) includes a body portion (110) and a forming portion (120). The body portion (110) may have a cylindrical shape. It may be configured to rotate around a central axis (X). During the process of forming the electrode, the body portion (110) may rotate around the central axis (X), and the electrode may be formed during this rotation process. That is, a pattern such as a groove or a pore may be formed on the electrode through the protrusion (125) described below. In particular, this may mean that a pattern such as a groove or a pore may be formed on the retaining portion of the electrode.

[0038] The molding part (120) may be a configuration that is coupled to the outer surface of the body part (110). In particular, the molding part (120) may be a configuration that is detachably coupled to the outer surface of the body part (110). Being detachably coupled means that it can be coupled to the body part (110) as needed and can also be separated from the body part (110) as needed. In this case, the molding part (120) can be freely coupled to or detached from the body part (110). Such a detachable shape may be a shape that is advantageous for replacing the molding part (120) with another molding part. Also, the molding part (120) may include a protrusion (125) that forms a retaining part.

[0039] The protrusion (125) can serve to form a pattern, such as a groove shape, indented in the retaining part. When the protruding protrusion (125) applies pressure and presses the retaining part, a pattern such as a groove can be formed in the retaining part. There may be multiple protrusions (125), and in this case, a pattern in which multiple grooves are formed can be formed in the retaining part.

[0040] When a groove-shaped pattern is formed in the electrode holding portion, the surface area in contact with the electrolyte may be increased. In this case, the insertion and extraction of lithium can occur smoothly in the electrode. Therefore, if an electrode with a pattern formed by such an electrode forming device (10) is manufactured and used, the problem of lithium precipitation can be prevented because the insertion and extraction of lithium from the electrode do not occur smoothly during rapid charging. That is, since the insertion and extraction of lithium are smooth, lithium may not be precipitated. In addition, since the pattern is formed on the electrode by the rotation of the body portion (110), the pattern can be formed on the electrode quickly and efficiently.

[0041] In addition, the electrode forming device (10) according to Embodiment 1 of the present invention has the effect of being able to produce and use a customized forming part (120) according to the situation without producing a whole forming roll, in relation to the fact that pattern conditions may differ depending on the length and position of the electrode.

[0042] In other words, conventionally, there was a problem where, after making a single forming roll according to the required conditions, the entire roll could not be used and had to be made anew when a different pattern was needed; however, the present invention can easily solve this problem. That is, when the required conditions change, the forming part (120) can be separated from the body part (110) and easily replaced with a new forming part to easily implement a new forming roll.

[0043] In addition, the electrode forming device (10) according to Embodiment 1 of the present invention may be provided with a plurality of forming sections (120). The plurality of forming sections (120) may be formed spaced apart from each other. Here, the distance between the forming sections (120) may all be the same (in this case, d1=d2). Also, protrusions (125) may be formed on each forming section (120). Furthermore, the protrusions (125) formed on these plurality of forming sections (120) may all be provided in the same shape. The term "same shape" may mean that the size and shape are the same. This may be a useful shape when the pattern shape formed on the electrode needs to be formed in the same shape or needs to be formed regularly. For example, it may be useful when forming the electrode into a pattern in which the same pattern shape is repeatedly formed at regular intervals.

[0044] Meanwhile, multiple molded parts (120) may be formed with different spacing from each other (in this case, d1 and d2 are different). Also, the protrusions (125) provided in each molded part (120) may have different shapes. That is, their shapes and sizes may be different.

[0045] Specifically, the molding part (120) may include a first molding part (121) and a second molding part (122). The first molding part (121) may be configured to include a first projection (121-1) and be coupled to the body part (110). The second molding part (122) may be a molding part (120) spaced apart from the first molding part (121). The second molding part (122) may be configured to be spaced apart from the first molding part (121) by a first interval (d1) in a direction parallel to the central axis (X) of the body part (110) and include a second projection (122-1). The second molding part (122) may also be configured to be coupled to the body part (110). Both the first molding part (121) and the second molding part (122) may be configured to be detachably coupled to the body part (110).

[0046] Also, the first projection (121-1) of the first molding part (121) and the second projection (122-1) of the second molding part (122) may have different sizes. They may have the same shape but different sizes, or they may have different shapes and different sizes simultaneously. For example, the second projection (122-1) may have a smaller shape or size than the first projection (121-1).

[0047] In addition, in the electrode forming device (10) according to Embodiment 1 of the present invention, the forming part (120) may further include a third forming part (123). The third forming part (123) may be configured to be positioned at a distance of a second interval (d2) in a direction parallel to the central axis (X) of the body part (110) from the second forming part (122). In a direction parallel to the central axis (X) of the body part (110), the first forming part (121) and the second forming part (122) may be spaced apart by a first interval (d1), and the second forming part (122) and the third forming part (123) may be spaced apart by a second interval (d2). Here, the first interval (d1) and the second interval (d2) may be different from each other. For example, the second interval (d2) may be smaller than the first interval (d1).

[0048] And the third molding part (123) may include a third projection (123-1). Here, the third projection (123-1) may have a different size from at least one of the first projection (121-1) and the second projection (122-1). Specifically, the third projection (123-1) may be different only from the first projection (121-1), the third projection (123-1) may be different only from the second projection (122-1), and the third projection (123-1) may also be different from both the first projection (121-1) and the second projection (122-1).

[0049] The first projection (121-1), the second projection (122-1), and the third projection (123-1) may have any two selected projections (125) that are different from each other, or all three may be different from each other. For example, the second projection (122-1) may be smaller than the first projection (121-1), and the third projection (123-1) may be smaller than the second projection (122-1). Also, the third projection (123-1) may have a shape different from at least one of the first projection (121-1) and the second projection (122-1).

[0050] In this way, the electrode forming device (10) according to Embodiment 1 of the present invention can have a suitable position, a suitable shape, and a suitable size depending on the necessary conditions. Accordingly, the shape of the forming part (120) can be easily designed to match the length of the electrode and the shape of the required pattern, and accordingly, the pattern electrode can be produced while effectively driving the roller unit (100).

[0051] In addition, by implementing an electrode forming device (10) having different protrusions (125) depending on the location, the performance of the rapid charging performance in the location that is inferior can be improved.

[0052]

[0053] Example 2

[0054] FIG. 2 is a perspective view illustrating an electrode forming apparatus according to Example 2 of the present invention.

[0055] Example 2 of the present invention differs from Example 1 in that, when compared to the electrode forming device according to Example 1 of the present invention, it includes a protrusion forming area and a protrusion non-forming area within a single detachable molding part.

[0056] Content common to Example 1 will be omitted as much as possible, and Example 2 will be described. That is, it is obvious that if content not explained in Example 2 is necessary, it can be considered as content of Example 1.

[0057] Referring to FIG. 2, an electrode forming device (20) according to embodiment 2 of the present invention includes a roller unit (200), and the roller unit (200) includes a body part (210) having a cylindrical shape and a forming part (220) that is detachably coupled to the outer surface of the body part (210) and includes a protrusion (225) that forms a retaining part.

[0058] In addition, in the electrode forming device (20) according to Embodiment 2 of the present invention, the forming part (220) includes a protrusion forming area (230) and a protrusion non-forming area (240). The protrusion forming area (230) is an area where a protrusion (225) is formed in the forming part (220). And the protrusion non-forming area (240) is an area where a protrusion (225) is not formed in the forming part (220). That is, one forming part (220) simultaneously includes the protrusion forming area (230) and the protrusion non-forming area (240).

[0059] These molding parts (220) may be provided in multiple numbers. And the multiple molding parts (220) may be formed in succession to each other. Being formed in succession to each other may mean that they are arranged in succession so that their outermost boundary lines meet each other. Referring to FIG. 2, the molding parts (220) may be arranged in succession in a direction parallel to the central axis (X) of the body part (210).

[0060] Here, multiple molded parts (220) may all have the same shape. Specifically, the lengths of the protrusion-forming regions (230) measured in a direction parallel to the central axis (X) of the body part (210) may be the same in all of the multiple molded parts (220). That is, the length of the protrusion-forming region (230) measured in the central axis (X) of the body part (210) in one molded part (220) may be equal to the length of the protrusion-forming region measured in the same way in another molded part (220). For example, referring to FIG. 2, the lengths of L1, L3, and L5 may be the same.

[0061] Likewise, the lengths of the non-protrusion areas (240) measured in a direction parallel to the central axis (X) of the body part (210) may be the same in all of the multiple molded parts (220). That is, the length of the non-protrusion area (240) measured in the central axis (X) of the body part (210) in one molded part (220) may be the same as the length of the non-protrusion area measured in the same way in another molded part (220). For example, referring to FIG. 2, the lengths of L2, L4, and L6 may be the same.

[0062] Also, the protrusions (225) included in the plurality of molded parts (220) may all be of the same shape. Being of the same shape may mean that they are the same in size and shape.

[0063] Meanwhile, multiple molding parts (220) may have different shapes. Specifically, the molding part (220) may include a first molding part (221) including a first protrusion (221-1) and a second molding part (222) including a second protrusion (222-1). The second molding part (222) may be positioned consecutively to the first molding part (221) in a direction parallel to the central axis (X) of the body part (210). Being positioned consecutively may mean that the boundary of the second molding part (222) and the boundary of the first molding part (221) are connected and arranged so that they meet each other. Also, the first protrusion (221-1) and the second protrusion (222-1) may have different sizes or different shapes. They may have the same shape but different sizes, or they may have different shapes and different sizes simultaneously. For example, the second projection (222-1) may have a smaller shape or a smaller size than the first projection (221-1).

[0064] In addition, in the electrode forming device (20) according to embodiment 2 of the present invention, the forming part (220) may further include a third forming part (223) located consecutively from the second forming part (222) in a direction parallel to the central axis (X) of the body part (210). And the third forming part (223) may include a third projection (223-1). Likewise, the boundary of the second forming part (222) and the boundary of the third forming part (223) may be arranged to be connected to each other so that they meet.

[0065] And the third projection (223-1) may have a different size from at least one of the first projection (221-1) and the second projection (222-1). Specifically, the third projection (223-1) may be different only from the first projection (221-1), the third projection (223-1) may be different only from the second projection (222-1), and the third projection (223-1) may also be different from both the first projection (221-1) and the second projection (222-1). Among the first projection (221-1), the second projection (222-1), and the third projection (223-1), any two selected projections (225) may be different from each other, or all three may be different from each other. For example, the second protrusion (222-1) may be smaller than the first protrusion (221-1), and the third protrusion (223-1) may be smaller than the second protrusion (222-1). Additionally, the third protrusion (223-1) may have a shape similar to at least one of the first protrusion (221-1) and the second protrusion (222-1).

[0066] And for various shapes that meet the requirements, the length of the protrusion forming area (230) measured in the direction of the central axis (X) of the body part (210) may differ from each other in at least two of the first forming part (221), the second forming part (222), and the third forming part (223). For example, L1 and L3 may differ from each other, L3 and L5 may differ from each other, or L1 and L5 may differ from each other. Also, L1, L3, and L5 may all have different lengths.

[0067] Likewise, the length of the non-protrusion area (240) measured in the direction of the central axis (X) of the body part (210) may also differ from each other in at least two of the first molded part (221), the second molded part (222), and the third molded part (223). For example, L2 and L4 may differ from each other, L4 may differ from each other, or L2 and L6 may differ from each other. Also, L2, L4, and L6 may all have different lengths.

[0068] The electrode molding device (20) according to Embodiment 2 of the present invention has the advantage that, as one molding part (220) includes a protrusion forming area (230) and a non-protrusion forming area (240) simultaneously, the area where a pattern is formed and the area where a pattern is not formed on the electrode can be designed at once, and thus the entire electrode design consisting of a pattern forming area and a non-pattern forming area can be molded at once with one molding of the roller unit (200).

[0069] In addition, the electrode forming device (20) according to Example 2 has the advantage of being able to easily and quickly match the first gap (d1) and the second gap (d2), which are the gaps between the necessary forming parts (220) described in Example 1. That is, by simply placing a plurality of forming parts (220) in succession, the first gap (d1) and the second gap (d2), which are the gaps between the necessary forming parts (220), are immediately matched, thus enabling faster and more efficient work.

[0070]

[0071] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and various implementations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0072] [Explanation of the symbol]

[0073] 10, 20: Electrode forming device

[0074] 100, 200: Roller unit

[0075] 110, 210: Body part

[0076] 120, 220: Molding section

[0077] 121, 221: 1st forming section

[0078] 121-1, 221-1: 1st projection

[0079] 122, 222: 2nd molding section

[0080] 122-1, 222-1: Second projection

[0081] 123, 223: 3rd molding section

[0082] 123-1, 223-1: Third projection

[0083] 125, 225: protrusion

[0084] 230: Protrusion formation area

[0085] 240: Area of ​​non-formed protrusions

[0086] d1: First interval

[0087] d2: Second interval

[0088] X: Central axis

Claims

1. An electrode forming device for forming an electrode including a retaining portion coated with an electrode active material, It includes a roller unit that forms the retaining part having the shape of a roller, and The above roller unit is, Body part; and An electrode forming device characterized by including a molding portion that is detachably coupled to the outer surface of the body portion and includes a projection that forms the retaining portion.

2. In Claim 1, The above-mentioned molding part is provided in multiple numbers, and An electrode forming device characterized in that a plurality of the above-mentioned forming parts are formed spaced apart from each other.

3. In Claim 2, An electrode forming device characterized in that the protrusions formed in a plurality of the above-mentioned forming parts are all provided in the same shape.

4. In Claim 2, The above body part has a cylindrical shape, The above-mentioned molding part is, A first molded portion including a first projection; and An electrode forming device characterized by including a second forming part including a second projection positioned at a first interval (d1) in a direction parallel to the central axis (X) of the body part.

5. In Claim 4, An electrode forming device characterized in that the first protrusion and the second protrusion have different sizes.

6. In Claim 4, The above-mentioned molding part is, An electrode forming device characterized by further including a third forming part that is spaced apart by a second interval (d2) in a direction parallel to the central axis (X) of the body part from the second forming part and includes a third projection.

7. In Claim 6, An electrode forming device characterized in that the third projection has a different size from at least one of the first projection and the second projection.

8. In Claim 1, The above-mentioned molding part is, The protrusion forming region, which is the region where the above-mentioned protrusion is formed, and An electrode forming device characterized by including a non-protrusion region, which is a region where the above-mentioned protrusion is not formed.

9. In Claim 8, The above-mentioned molding part is provided in multiple numbers, and An electrode forming device characterized in that a plurality of the above-mentioned forming parts are formed in succession to each other.

10. In Claim 9, The above body part has a cylindrical shape, The protrusions included in the plurality of the above-mentioned molded parts are all of the same shape, and The lengths of the protrusion-forming regions measured in a direction parallel to the central axis (X) of the body part are all the same in the plurality of molded parts, and An electrode forming device characterized in that the lengths of the non-protrusion regions measured in a direction parallel to the central axis (X) of the body part are all the same in the plurality of molded parts.

11. In Claim 8, The above body part has a cylindrical shape, The above-mentioned molding part is, A first molded portion including a first projection; and An electrode forming device characterized by including a second forming part that is positioned in succession parallel to the central axis (X) of the body part and includes a second projection.

12. In Claim 11, An electrode forming device characterized in that the first protrusion and the second protrusion have different sizes.

13. In Claim 11, The above-mentioned molding part is, An electrode forming device characterized by further including a third forming part that is positioned consecutively from the second forming part in a direction parallel to the central axis (X) of the body part and includes a third projection.

14. In Claim 13, An electrode forming device characterized in that the third projection has a different size from at least one of the first projection and the second projection.

15. In Claim 13, The length of the protrusion-forming area measured in the direction of the central axis (X) of the body part is different from each other in at least two of the first molding part, the second molding part, and the third molding part, and An electrode forming device characterized in that the length of the area of ​​non-protrusion formed by measuring in the direction of the central axis (X) of the body part is also different from at least two of the first forming part, the second forming part, and the third forming part.

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