KR20220010167A - Electrode assembly manufacturing equipment and mauufacturing method of electrode assembly - Google Patents

Abstract

An electrode assembly manufacturing device according to an embodiment of the present invention includes: an unwinder for continuously supplying an electrode sheet in one direction; a thickness measuring unit for measuring the thickness of the electrode sheet in real time; and a notching unit for continuously forming notched electrode tabs on one side of the electrode sheet. The notching unit adjusts the position of a next notched electrode tab based on a change in the thickness of the electrode sheet measured by the thickness measuring unit after forming one notched electrode tab.

Description

Electrode assembly manufacturing apparatus and electrode assembly manufacturing method TECHNICAL FIELD

The present invention relates to an electrode assembly manufacturing apparatus and an electrode assembly manufacturing method, and more particularly, to an electrode assembly manufacturing apparatus for forming a notched electrode tab and an electrode assembly manufacturing method using the same.

Recently, interest in energy storage technology is increasing. Efforts for research and development of electrochemical devices are becoming more concrete as the field of application expands to cell phones, camcorders, notebook PCs, and even the energy of electric vehicles. Electrochemical devices are receiving the most attention in this regard, and among them, the development of rechargeable batteries that can be charged and discharged is the focus of interest. and battery design research and development.

Among the currently applied secondary batteries, lithium secondary batteries developed in the early 1990s have a higher operating voltage and significantly higher energy density than conventional batteries such as Ni-MH, Ni-Cd, and lead sulfate batteries that use aqueous electrolyte solutions. is in the spotlight as

The lithium secondary battery may be typically classified into a lithium metal battery, a lithium ion battery, and a lithium polymer battery. Among them, a lithium metal battery uses lithium metal or a lithium alloy as an anode. Among them, lithium metal has the advantage of obtaining the highest energy density, so continuous research is being conducted.

In addition, depending on the shape of the battery case, the secondary battery includes a cylindrical battery in which the electrode assembly is embedded in a cylindrical metal can, a prismatic battery in which the electrode assembly is embedded in a prismatic metal can, and the electrode assembly in a pouch-type case of an aluminum laminate sheet. It is classified as a built-in pouch-type battery. Among them, the cylindrical battery has an advantage in that it has a relatively large capacity and is structurally stable.

The electrode assembly embedded in the battery case is a charging/discharging power generating element having a stacked structure of a positive electrode, a separator, and a negative electrode, and is classified into a jelly roll type, a stack type, and a stack/folding type. The jelly roll type is a form in which a separator is interposed between a long sheet-type positive electrode and a negative electrode coated with an active material, and the stack type is a form in which a plurality of positive and negative electrodes of a predetermined size are sequentially stacked with a separator interposed therebetween, stack /Folding type is a composite structure of jelly-roll type and stack type. Among them, the jelly roll type electrode assembly has advantages of being easy to manufacture and having high energy density per weight.

Here, the lithium secondary battery is manufactured in various sizes in consideration of the field of use, and for this purpose, a process of cutting to a predetermined size is essential.

In particular, in order to form an electrode tab, a process of notching a continuous electrode sheet at a unit electrode interval is required. In the notching process, a method of notching a part of the electrode sheet using a cutter is generally used.

1 is a partial view of an electrode sheet including a notched electrode tab manufactured by a conventional notching process. 2 and 3 are plan views of the jelly roll electrode assembly including the electrode sheet of FIG. 1 as viewed from different angles. Specifically, FIG. 2 is a view of the jellyroll electrode assembly 10 on the xy plane, and FIG. 3 is a view of the jellyroll electrode assembly 10 as viewed on the xz plane.

1 to 3 , a plurality of notched electrode tabs 21a, 21b, and 21c are formed on one side of the electrode sheet 20 that continuously moves in one direction. Specifically, the notched electrode tabs 21a, 21b, and 21c may be sequentially formed by cutting a portion of the electrode sheet 20 with a cutter except for regions corresponding to the notched electrode tabs 21a, 21b, and 21c.

At this time, the electrode sheet 20 is wound together with a separator (not shown) to form the jelly roll electrode assembly 10, and the plurality of notched electrode tabs 21a, 21b, 21c are to be joined by a method such as welding. can For bonding, the plurality of notched electrode tabs 21a, 21b, and 21c should be aligned while securing a minimum overlapping section. Accordingly, the distances d1 and d2 between the plurality of notched electrode tabs 21a, 21b, and 21c are equal to those of the plurality of notched electrode tabs 21a, 21b, and 21c based on the wound jelly roll electrode assembly 10 . It is preferable to adjust in consideration of the alignment.

However, the thickness of the electrode sheet 20 is slightly increased or decreased during the process. If this part is not taken into account, as shown in FIGS. 2 and 3 , the plurality of notched electrode tabs 21a, 21b, and 21c ) may result in misalignment in which the degree of alignment varies. If the alignment of the notched electrode tabs 21a, 21b, and 21c is not good as described above, the overlapping section of the notched electrode tabs 21a, 21b, and 21c decreases, making it difficult to secure a bonding area.

An object of the present invention is to provide an electrode assembly manufacturing apparatus and an electrode assembly manufacturing method capable of reducing bonding defects between the notched electrode tabs by correcting the alignment position of the notched electrode tabs.

However, the problems to be solved by the embodiments of the present invention are not limited to the above problems and may be variously expanded within the scope of the technical idea included in the present invention.

An electrode assembly manufacturing apparatus according to an embodiment of the present invention includes: an unwinder for continuously supplying an electrode sheet in one direction; a thickness measuring unit for measuring the thickness of the electrode sheet in real time; and a notched portion for continuously forming notched electrode tabs on one side of the electrode sheet. After the formation of one notched electrode tab, the notched part adjusts the position of the next notched electrode tab based on the thickness change of the electrode sheet measured by the thickness measuring part.

The thickness measuring part may be located adjacent to the notched part.

The thickness measuring part may be located closer to the unwinder than the notched part.

The electrode assembly manufacturing apparatus may further include a winding unit for manufacturing a jelly roll electrode assembly by winding the electrode sheet together with a separator.

An electrode assembly manufacturing method according to an embodiment of the present invention includes continuously supplying an electrode sheet in one direction using an unwinder; measuring the thickness of the electrode sheet in real time using a thickness measuring unit; and continuously forming notched electrode tabs on one side of the electrode sheet using the notched part. The continuously forming the notched electrode tabs may include adjusting an interval between the notched electrode tabs according to a change in the thickness of the electrode sheet measured by the thickness measuring unit.

The thickness measuring part may be located adjacent to the notched part.

The thickness measuring part may be located closer to the unwinder than the notched part to measure a change in thickness of the electrode sheet after the notched part forms one notch electrode tab.

The electrode assembly manufacturing method may further include manufacturing a jelly roll electrode assembly by winding the electrode sheet together with a separator.

In the step of adjusting the spacing between the notched electrode tabs, an alignment reference value is set by simulating the positions of the notched electrode tabs in the jelly roll electrode assembly, and a preset alignment reference value is set due to the measured thickness change of the electrode sheet It is possible to calculate the extent to which

In the step of adjusting the distance between the notched electrode tabs, the circumferential length data of the jelly roll electrode assembly up to the next notched electrode tab based on one notched electrode tab and the electrode sheet after the formation of the one notched electrode tab Based on the thickness change data of , the position of the next notched electrode tab may be adjusted.

According to embodiments of the present invention, the alignment position of the notched electrode tab with respect to the jelly roll electrode assembly may be corrected by measuring the thickness of the electrode sheet in real time and reflecting this in adjusting the spacing between the notched electrode tabs. Accordingly, a bonding defect between the notched electrode tabs may be reduced. In addition, it is possible to reduce the time and effort to adjust the conditions for aligning the notched electrode tabs, thereby increasing production convenience and efficiency and reducing production costs.

Effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is a partial view of an electrode sheet including a notched electrode tab manufactured by a conventional notching process.
2 and 3 are plan views of the jelly roll electrode assembly including the electrode sheet of FIG. 1 as viewed from different angles.
4 is a schematic diagram of an electrode assembly manufacturing apparatus according to an embodiment of the present invention.
5 is a perspective view showing a thickness measuring part and a notched part corresponding to part “A” of FIG. 4 .
FIG. 6 is a partial view showing a winding unit corresponding to part “B” of FIG. 4 .
7 and 8 are plan views of the jelly roll electrode assembly manufactured by the apparatus for manufacturing the electrode assembly of FIG. 4 as viewed from different angles.
9 is a partial view illustrating an electrode assembly manufacturing apparatus according to a comparative example of the present invention.

Hereinafter, with reference to the accompanying drawings, various embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. The present invention may be embodied in several different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

In addition, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the illustrated bar. In order to clearly express various layers and regions in the drawings, the thicknesses are enlarged. And in the drawings, for convenience of description, the thickness of some layers and regions are exaggerated.

Also, when a part of a layer, film, region, plate, etc. is said to be “on” or “on” another part, it includes not only cases where it is “directly on” another part, but also cases where there is another part in between. . Conversely, when we say that a part is "just above" another part, we mean that there is no other part in the middle. In addition, to be "on" or "on" the reference part means to be located above or below the reference part, and to necessarily mean to be located "on" or "on" in the direction opposite to gravity no.

In addition, throughout the specification, when a part "includes" a certain component, this means that other components may be further included, rather than excluding other components, unless otherwise stated.

In addition, throughout the specification, when referring to "planar", it means when the target part is viewed from above, and "cross-sectional" means when viewed from the side when a cross-section of the target part is vertically cut.

4 is a schematic diagram of an electrode assembly manufacturing apparatus according to an embodiment of the present invention. 5 is a perspective view showing a thickness measuring part and a notched part corresponding to part “A” of FIG. 4 . FIG. 6 is a partial view showing a winding unit corresponding to part “B” of FIG. 4 .

First, referring to FIGS. 4 and 5 , an electrode assembly manufacturing apparatus 100 according to an embodiment of the present invention includes an unwinder 200 for continuously supplying an electrode sheet 20 in one direction, an electrode sheet It includes a thickness measuring unit 300 for measuring the thickness of 20 in real time, and a notching unit 400 continuously forming notched electrode tabs 21a and 21b on one side of the electrode sheet 20 . In addition, the electrode assembly manufacturing apparatus 100 includes an unwinder 200 for continuously supplying different electrode sheets 30 in one direction, a thickness measuring unit 300 for measuring the thickness of the electrode sheet 30 in real time, and The electrode sheet 30 may further include a notched portion 400 continuously forming notched electrode tabs on one side thereof. That is, as the electrode sheets 20 and 30 are configured in plurality, the unwinder 200 , the thickness measuring part 300 and the notching part 400 may also be configured in plurality. One of the electrode sheets 20 and 30 may be a positive electrode sheet or a negative electrode sheet.

The unwinder 200 is a configuration that continuously supplies the rectangular electrode sheet 20 in one direction in a continuous Roll to Roll process, and although not specifically shown, it may further include a configuration such as a roller can

The thickness measuring unit 300 is configured to measure the thickness of the electrode sheet 20 in real time, and there is no particular limitation on a measuring method or equipment, but may include a measuring device such as a sensor, for example.

The notched part 400 is configured to form notched electrode tabs 21a and 21b on one side of the electrode sheet 20 , and a cutter 410 for cutting a part of the electrode sheet 20 and the electrode sheet 20 . It may include a lower die 420 for fixing the. However, the cutter 410 and the lower die 420 are exemplary configurations according to the present embodiment, and may include other punching machines that form the notched electrode tabs 21a and 21b.

The notched electrode tabs 21a and 21b may be integrally formed with the electrode sheet 20 , and the notched portion 400 is a portion where the notched electrode tabs 21a and 21b are formed with respect to one side of the electrode sheet 20 . It may be formed by a method of removing the remaining portion except for. In addition, the notched part 400 may sequentially form the notched electrode tabs 21a and 21b spaced apart by a predetermined interval d with respect to the continuously moving electrode sheet 20 in the roll-to-roll process.

At this time, in the conventional case shown in FIGS. 1 to 3 , the circumferential length from the previous notched electrode tab 21a to the next notched electrode tab 21b predicted based on the outer diameter of the jelly roll electrode assembly 10 is calculated. Intervals d1, d2, and d3 between the notched electrode tabs 21a, 21b, and 21c may be set. However, in the conventional case, as described above, in the final rolled jelly roll electrode assembly 10 without considering the thickness change of the electrode sheet 20, alignment error between the notched electrode tabs 21a, 21b, and 21c may occur. As the number of windings increases and the number of notched electrode tabs increases, a large alignment error between the notched electrode tabs 21a, 21b, and 21c may occur even with a slight change in the thickness of the electrode sheet 20 .

On the other hand, in the electrode assembly manufacturing apparatus according to the present embodiment, the thickness of the electrode sheet 20 is measured in real time, and the thickness measurement unit 300 for detecting the change is intended to solve the above problems. Specifically, the notched part 400 is the position of the next notched electrode tab 21b based on the thickness change of the electrode sheet 20 measured by the thickness measuring part 300 after the formation of one notched electrode tab 21a; That is, the distance d between the notched electrode tabs 21a and 21b is adjusted.

Specifically, by simulating the positions of the notched electrode tabs 21a and 21b in the jelly roll electrode assembly 10, an alignment reference value is set, and a change in the thickness of the electrode sheet 20 is measured, and the The degree of deviation from the set alignment reference value, that is, the alignment error may be calculated. The position of the next notched electrode tab 21b may be set by adding a value for compensating for the calculated alignment error to the estimated circumferential length from the previous notched electrode tab 21a to the next notched electrode tab 21b. The notched part 400 may receive the calculated value as described above to form the next notched electrode tab 21b. On the other hand, although not specifically shown, in order to calculate the circumferential length from one notched electrode tab 21a to the next notched electrode tab 21b, the electrode assembly manufacturing apparatus according to the present embodiment includes the jelly being wound up. A measuring device for measuring a radial length or a circumferential length of the roll electrode assembly 10 in real time may be further included.

Next, referring to FIGS. 4 and 6 , in the electrode assembly manufacturing apparatus 100 according to the present embodiment, the electrode sheets 20 and 30 are wound together with the separator 40 to manufacture a jelly roll electrode assembly. (500) may be further included.

Specifically, the winding unit 500 may include a plurality of moving members and rollers, and each of the electrode sheets 20 and 30 and the separator 40 are continuously moved, respectively, and are wound together around the core 510 to make jelly A roll electrode assembly can be manufactured. The separator 40 is configured in plurality, and the electrode sheet 20 , the separator 40 , the electrode sheet 30 , and the separator 40 may be wound while being disposed in this order.

7 and 8 are plan views of the jelly roll electrode assembly manufactured by the apparatus for manufacturing the electrode assembly of FIG. 4 as viewed from different angles. Specifically, FIG. 7 is a view of the jelly roll electrode assembly 10 on the xy plane, and FIG. 3 is a view of the jelly roll electrode assembly 10 on the xz plane.

7 and 8 , the jelly roll electrode assembly 10 manufactured by the electrode assembly manufacturing apparatus 100 according to the present embodiment exhibits a change in the thickness of the fine electrode sheet 20 that changes during the roll-to-roll process. Since the spacing between the notched electrode tabs 21a, 21b, and 21c is adjusted to reflect this, the alignment of the notched electrode tabs 21a, 21b, and 21c is good, and a sufficient overlapping section for bonding can be secured. Ultimately, it is possible to reduce bonding defects between the notched electrode tabs 21a , 21b , and 21c , and it is possible to reduce the time and effort to adjust the conditions for aligning the notched electrode tabs 21a , 21b , and 21c , thereby increasing production convenience and efficiency. and production cost can be reduced.

Hereinafter, a method for manufacturing an electrode assembly according to an embodiment of the present invention using the above-described electrode assembly manufacturing apparatus 100 will be described in detail.

4 to 6 , in the method for manufacturing an electrode assembly according to an embodiment of the present invention, continuously supplying an electrode sheet 20 in one direction using an unwinder 200, a thickness measuring unit Measuring the thickness of the electrode sheet 20 in real time using the 300 and continuously forming the notched electrode tabs 21a and 21b on one side of the electrode sheet using the notched part 400 .

Thereafter, a step of manufacturing the jelly roll electrode assembly 10 (refer to FIGS. 7 and 8 ) by winding the electrode sheet 20 together with the separator 40 through the winding unit 500 may be followed. The two electrode sheets 20 and 30 and the two separators 40 may be wound on the core 510 while alternately positioned together.

In the step of continuously forming the notched electrode tabs 21a and 21b, the spacing d between the notched electrode tabs 21a and 21b according to the thickness change of the electrode sheet 20 measured by the thickness measuring unit 300 . ) to control. Specifically, in the step of adjusting the distance d between the notched electrode tabs 21a and 21b, the alignment reference value is obtained by simulating the positions of the notched electrode tabs 21a and 21b in the jelly roll electrode assembly 10. set, and by measuring the change in the thickness of the electrode sheet 20, the degree of deviation from the preset alignment reference value due to the thickness change, that is, the alignment error can be calculated. In other words, in the step of adjusting the distance d between the notched electrode tabs 21a and 21b, the jelly roll electrode assembly from one notched electrode tab 21a to the next notched electrode tab 21b Based on the circumferential length data of (10) and the thickness change data of the electrode sheet 20 after the formation of one notched electrode tab 21a, the position of the next notched electrode tab 21b may be adjusted. At this time, the jelly roll electrode assembly 10 being wound to collect and calculate the circumferential length data of the jelly roll electrode assembly 10 from one notched electrode tab 21a to the next notched electrode tab 21b. ) of measuring a radial length or a circumferential length in real time may be further performed. Accordingly, in the manufactured jelly roll electrode assembly 10 , as shown in FIGS. 7 and 8 , the notched electrode tabs 21a , 21b , and 21c may exhibit good alignment. The detailed information is redundant with the previous description, so it will be omitted.

On the other hand, referring to FIGS. 4 and 5 together, the thickness measuring unit 300 according to the present embodiment may be located adjacent to the notched unit 400 , and is located in the unwinder 200 rather than the notched unit 400 . can be located close. According to the configuration as described above, the notched portion 400 may form the notched electrode tab 21b in a state in which the thickness of the electrode sheet 20 is all measured and all changes thereof are sensed. For a clear understanding, an electrode assembly manufacturing apparatus according to a comparative example of the present invention will be described with reference to FIG. 9 .

9 is a partial view illustrating an electrode assembly manufacturing apparatus according to a comparative example of the present invention.

Referring to FIG. 9 , in the electrode assembly manufacturing apparatus according to this comparative example, the notched part 4 is positioned ahead of the thickness measuring part 3 in the roll-to-roll process. In other words, any one point of the electrode sheet 20 continuously moving in one direction reaches the notched part 4 before the thickness measuring part 3 . In this case, when the time point shown in FIG. 9 is the time point at which the notched part 4 forms one notched electrode tab and the next notched electrode tab is formed as time elapses, the interval between one notched electrode tab and the next notched electrode tab It cannot be said that all the thicknesses of the electrode sheet 20 were measured. This is because, as shown, there is a section in which the thickness of the electrode sheet 20 is not confirmed between the notched part 4 and the thickness measuring part 3 . Therefore, there may be an error in the value to compensate for the alignment error calculated based on the thickness measurement of the electrode sheet 20 .

On the other hand, in the electrode assembly manufacturing apparatus according to the present embodiment, the thickness measuring unit 300 may be positioned adjacent to the notched part 400 , and positioned closer to the unwinder 200 than the notched part 400 . can do. Accordingly, when the notched part 400 forms the notched electrode tab, the thickness of the electrode sheet 20 between the previous notched electrode tab and the corresponding notched electrode tab is all measured by the thickness measuring part 300 . and can be detected. Also in the electrode assembly manufacturing method according to this embodiment, the thickness measuring part 300 is located closer to the unwinder 200 than the notched part 400, and after the notched part 400 forms one notch electrode tab, A change in the thickness of the electrode sheet 20 may be measured. Ultimately, the position of the notched electrode tab may be adjusted while all the thicknesses of the electrode sheet 20 are measured and reflected.

In this embodiment, terms indicating directions such as front, rear, left, right, up, and down are used, but these terms are for convenience of explanation only, and may vary depending on the location of the object or the position of the observer. .

Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims are also provided. is within the scope of the

200: unwinder
300: thickness measurement unit
400: notching part
500: winding

Claims (10)

an unwinder that continuously supplies the electrode sheet in one direction;
a thickness measuring unit for measuring the thickness of the electrode sheet in real time; and
and a notch portion for continuously forming notched electrode tabs on one side of the electrode sheet,
An electrode assembly manufacturing apparatus for adjusting a position of the next notched electrode tab based on a change in the thickness of the electrode sheet measured by the thickness measuring unit after the notched part is formed by the notched electrode tab. In claim 1,
The thickness measuring part is an electrode assembly manufacturing apparatus positioned adjacent to the notch part. In claim 1,
The thickness measuring part is located closer to the unwinder than the notch part. In claim 1,
The electrode assembly manufacturing apparatus further comprising a winding unit for manufacturing a jelly roll electrode assembly by winding the electrode sheet together with the separator. continuously supplying the electrode sheet in one direction using an unwinder;
measuring the thickness of the electrode sheet in real time using a thickness measuring unit; and
and continuously forming notched electrode tabs on one side of the electrode sheet using a notched part,
The continuously forming the notched electrode tabs may include adjusting a distance between the notched electrode tabs according to a change in thickness of the electrode sheet measured by the thickness measuring unit. In claim 5,
The thickness measuring part is a method of manufacturing an electrode assembly positioned adjacent to the notch part. In claim 5,
The thickness measuring part is located closer to the unwinder than the notched part, and after the notching part forms one notch electrode tab, the thickness change of the electrode sheet is measured. In claim 5,
The method of manufacturing an electrode assembly further comprising the step of winding the electrode sheet together with a separator to prepare a jelly roll electrode assembly. In claim 8,
In the step of adjusting the spacing between the notched electrode tabs,
A method of manufacturing an electrode assembly for setting an alignment reference value by simulating the positions of the notched electrode tabs in the jelly roll electrode assembly, and calculating a degree of deviation from a predetermined alignment reference value due to a measured thickness change of the electrode sheet. In claim 8,
In the step of adjusting the spacing between the notched electrode tabs,
Based on the circumferential length data of the jelly roll electrode assembly up to the next notched electrode tab based on one notched electrode tab and the thickness change data of the electrode sheet after the formation of the one notched electrode tab, the position of the next notched electrode tab is determined A method of making a controlled electrode assembly.

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