KR20240015577A - Manufacturing method and manufacturing device for secondary battery and secondary battery manufactured by the same - Google Patents

Abstract

The present invention relates to a secondary battery manufacturing method, manufacturing device, and secondary battery manufactured thereby. The present invention relates to a secondary battery manufacturing method, manufacturing apparatus, and secondary battery manufactured thereby. In the process of connecting the electrode tab of an electrode assembly and the electrode lead by welding, defects such as damage or disconnection of the electrode tab do not occur. , relates to a secondary battery manufacturing method and manufacturing device that realize excellent quality by preventing welding defects such as weak welding or overwelding, and secondary batteries manufactured thereby.

Description

Secondary battery manufacturing method, manufacturing device and secondary battery manufactured thereby {MANUFACTURING METHOD AND MANUFACTURING DEVICE FOR SECONDARY BATTERY AND SECONDARY BATTERY MANUFACTURED BY THE SAME}

The present invention relates to a secondary battery manufacturing method, manufacturing device, and secondary battery manufactured thereby. The present invention relates to a secondary battery manufacturing method, manufacturing apparatus, and secondary battery manufactured thereby. In the process of connecting the electrode tab of an electrode assembly and the electrode lead by welding, defects such as damage or disconnection of the electrode tab do not occur. , relates to a secondary battery manufacturing method and manufacturing device that realize excellent quality by preventing welding defects such as weak welding or overwelding, and secondary batteries manufactured thereby.

In recent years, the price of energy sources has risen due to the depletion of fossil fuels, and interest in environmental pollution has increased, and the demand for eco-friendly alternative energy sources has become an essential factor for future life. Accordingly, research continues on various power production technologies such as solar power, wind power, and tidal power, and there is also great interest in power storage devices such as batteries to use the electric energy produced in this way more efficiently.

Moreover, as technology development and demand for electronic mobile devices and electric vehicles using batteries increase, the demand for batteries as an energy source is rapidly increasing, and accordingly, much research is being conducted on batteries that can meet various needs. there is.

Secondary batteries are receiving a lot of attention as an energy source in a variety of products such as mobile devices and electric vehicles. These secondary batteries are an excellent energy resource that can replace the use of existing products using fossil fuels, and are attracting attention as an eco-friendly energy source because they do not generate by-products due to energy use.

Figure 1 is a side view showing a process for connecting an electrode tab and an electrode lead using a conventional secondary battery manufacturing method.

Referring to FIG. 1, in the conventional secondary battery manufacturing method, the process of connecting the electrode tab and electrode lead first goes through a pre-welding step (see ① in FIG. 1) and then through the main welding step (see ② in FIG. 1). carried out.

The pre-welding step (see ① in FIG. 1) is a step of gathering a plurality of electrode tabs extending from the electrodes of the electrode assembly and joining them to each other through ultrasonic welding. Through this, an electrode tab assembly can be formed. Free welding was a method of placing a plurality of electrode tabs between the upper horn and the lower anvil and applying ultrasonic vibration (B) to the horn while physically pressing through the horn and anvil.

The main welding step (see ② in FIG. 1) is a step of joining electrode leads to the assembled electrode tab assembly. In this step, laser welding was performed with a laser welder to join the electrode tab and electrode lead.

This conventional method had the following problems. First, because the pre-welding method applies physical pressure to the electrode tab with a horn and anvil and applies ultrasonic vibration with the horn, there was a problem of inevitably damaging the electrode tab. Additionally, during ultrasonic welding, there was a problem of welding defects such as weak welding and excessive welding due to abnormal welding conditions such as energy, power, welding time, and applying pressure. In addition, there was a problem of welding defects and electrode tab disconnection defects due to deviation in the horizontality of the horn and anvil or abnormal lamination during welding.

And there were inevitable problems that occurred due to the use of ultrasonic welding horns and anvils. Specifically, there was a problem requiring replacement cycle management due to wear of the horn and anvil, and there was a risk of disconnection of the electrode tab due to the edge curvature radius (edge R) of the horn and anvil. Additionally, there was a risk of welding defects due to poor condition of the ultrasonic welder.

Also, in the main welding stage, when the electrode lead overlaps the electrode tab, there was a problem that the edge of the electrode lead scratched the electrode tab, causing damage to the electrode tab. During laser welding, the electrode tab was scratched by the laser mask jig. There was also a problem that occurred.

The present invention was developed to solve the above problems, and the object of the present invention is to prevent defects such as damage or disconnection of the electrode tab from occurring in the process of connecting the electrode tab of the electrode assembly and the electrode lead by welding, and to prevent The object of the present invention is to provide a secondary battery manufacturing method, manufacturing device, and secondary battery manufactured thereby that achieve excellent quality by preventing welding defects such as welding or overwelding.

The secondary battery manufacturing method according to the present invention relates to a secondary battery manufacturing method in which a plurality of electrode tabs extending from one end of an electrode assembly formed by stacking electrodes and separators are welded to an electrode lead, including: (a) a tape of the required size and shape; Preparing, (b) gathering a plurality of electrode tabs to form an electrode tab laminate, (c) taping a tape to the electrode tab laminate, and (d) taping completed electrode tab laminate and electrode It includes welding the leads.

Between steps (c) and (d), (c-1) may further include a cutting step of cutting one end of the taped electrode tab laminate.

(a) The step of preparing the tape may be a step of preparing the tape by cutting it into the required size and shape.

(b) The step of forming the electrode tab laminate may be to press or guide a plurality of electrode tabs above and below the electrode tab to gather the electrode tabs to form the electrode tab laminate.

(c) In the taping step, the tape may be attached to both ends of the electrode tab laminate based on the width direction of the electrode tab laminate.

(c) In the taping step, the tape may be attached while wrapping the upper, side, and lower surfaces of the electrode tab laminate.

(c) In the taping step, the tape may not be attached to the portion where the electrode lead is to be welded on the upper and lower surfaces of the electrode tab laminate.

(c) In the taping step, the tape is attached to both ends of the electrode tab laminated body based on the width direction of the electrode tab laminated body, and a surplus portion is formed that protrudes further outward than the width direction end of the electrode tab laminated body. The tape may be attached to the electrode tab laminate.

(c) In the taping step, the surplus portion may be formed so that a part of the tape located further outside the width direction end of the electrode tab laminate faces and adheres to another part of the tape.

Steps (b) and (c) can be done together.

(d) The step of welding the electrode lead may be welding the electrode tab stack and the electrode lead by laser welding.

(d) In the step of welding the electrode lead, the excess parts located on both sides of the electrode tab laminate are held with a clamping device and pulled to both sides based on the width direction of the electrode tab laminate, and the electrode tab laminate and the electrode lead are welded together. It could be welding.

The secondary battery manufacturing device according to the present invention relates to a secondary battery manufacturing device for welding a plurality of electrode tabs extending from one end of an electrode assembly formed by stacking electrodes and separators to an electrode lead, and cutting the tape into the required size and shape. A tape cutting unit, a tab guide for gathering a plurality of electrode tabs to form an electrode tab laminate, a tape applicator for taping the cut tape to the electrode tab laminate, and a laser welder for welding the taped electrode tab laminate and electrode leads. Includes.

The tape attacher tapes the tape to the electrode tab laminate, and can be attached while wrapping the top, side, and bottom surfaces of the electrode tab laminate.

The tape attacher may attach the tape to the electrode tab stack so that a surplus portion protruding further outward than the width direction end of the electrode tab is formed.

It may further include a clamping device that pulls the surplus portions located on both sides of the electrode tab laminated body to both sides based on the width direction of the electrode tab laminated body.

It may further include a cutter for cutting one end of the electrode tab laminate on which taping has been completed by the tape attacher.

The secondary battery according to the present invention includes an electrode assembly formed by stacking an electrode and a separator, a pouch that accommodates the electrode assembly in an internal space, and an electrode formed by gathering a plurality of electrode tabs extending from one end of the electrode assembly but located inside the pouch. A tab laminate, a tape surrounding the electrode tab laminate; And one side is connected to the electrode tab laminate, and the other side includes an electrode lead that protrudes to the outside of the pouch.

The tape may be attached to both ends of the electrode tab laminate based on the width direction of the electrode tab laminate.

The tape is attached to both ends of the electrode tab laminated body in the width direction of the electrode tab laminated body, and may include a surplus portion that protrudes further outward than the ends in the width direction (W) of the electrode tab laminated body.

The surplus portion may have a form in which a part of the tape located further outside an end in the width direction (W) of the electrode tab laminate and another part of the tape face each other and are adhered.

The secondary battery manufacturing method and manufacturing device according to the present invention, and the secondary battery manufactured thereby, do not cause defects such as damage or disconnection of the electrode tab in the process of connecting the electrode tab of the electrode assembly and the electrode lead by welding, and approximately Excellent quality can be achieved by preventing welding defects such as welding or overwelding.

Figure 1 is a side view showing a process for connecting an electrode tab and an electrode lead using a conventional secondary battery manufacturing method.
Figure 2 is a side view showing a process of connecting an electrode tab and an electrode lead by the secondary battery manufacturing method according to Example 1 of the present invention.
Figure 3 is a side view showing a process of connecting an electrode tab and an electrode lead according to a modification of Example 1 of the present invention.
Figure 4 is a perspective view showing a state in which a tape is attached to an electrode tab laminate.
Figure 5 is a perspective view showing a state in which one end of the electrode tab laminate is cut.
Figure 6 is a perspective view showing the internal shape of a secondary battery according to Example 2 of the present invention.
Figure 7 is a side view showing a process of connecting an electrode tab and an electrode lead by the secondary battery manufacturing method according to Example 3 of the present invention.
Figure 8 is a perspective view showing a state in which a tape is attached to an electrode tab laminate in Example 3 of the present invention.
Figure 9 is a cross-sectional view showing the principle by which the surplus portion of the tape is created in Embodiment 3 of the present invention.
Figure 10 is a perspective view showing a state in which one end of the electrode tab laminate is cut in Example 3 of the present invention.
Figure 11 is a perspective view showing the internal shape of a secondary battery according to Example 4 of the present invention.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention can be implemented in various different forms and is not limited or restricted by the following examples.

In order to clearly explain the present invention, detailed descriptions of parts unrelated to the description or related known technologies that may unnecessarily obscure the gist of the present invention have been omitted, and reference signs are added to components in each drawing in this specification. In this regard, identical or similar reference signs are used to designate identical or similar components throughout the specification.

In addition, terms or words used in this specification and patent claims should not be construed as limited to their usual or dictionary meanings, and the inventor appropriately defines the concept of terms in order to explain his or her invention in the best way. It must be interpreted with meaning and concept consistent with the technical idea of the present invention based on the principle that it can be done.

Example 1

Figure 2 is a side view showing a process of connecting an electrode tab and an electrode lead by the secondary battery manufacturing method according to Example 1 of the present invention. Figure 3 is a side view showing a process of connecting an electrode tab and an electrode lead according to a modification of Example 1 of the present invention. Figure 4 is a perspective view showing a state in which a tape is attached to an electrode tab laminate. Figure 5 is a perspective view showing a state in which one end of the electrode tab laminate is cut.

Referring to FIG. 2, the secondary battery manufacturing method according to Example 1 of the present invention involves attaching a plurality of electrode tabs 20 extending from one end of the electrode assembly 10, which is formed by stacking electrodes and separators, to the electrode lead 40. It may be related to a welding secondary battery manufacturing method. The electrode assembly 10 is formed by alternately stacking electrodes and separators, and the electrode tab 20 may be a metal tab connected to the electrode and protruding from one side of the electrode. Accordingly, the plurality of electrode tabs 20 may have a structure extending from one end of the electrode assembly 10. A secondary battery can be manufactured by combining the plurality of electrode tabs 20 and combining them with the electrode lead 40.

The secondary battery manufacturing method according to Example 1 of the present invention includes (a) preparing a tape, (b) forming an electrode tab laminate, (c) taping the tape, and (d) electrode lead. It may include the step of welding.

(a) The step of preparing the tape may be the step of preparing the tape 31 of the required size and shape. The diagram in Figure 2 (a) shows this step. In this step, the tape 31 can be cut using a tape cutting unit (not shown) that cuts the tape 31. The tape 31 can be prepared by cutting the tape 31 into the required size and shape using a tape cutting unit.

Figure 2(a) shows the tape 31 whose cutting has been completed. Here, the tape 31 of the required size and shape may mean that the tape 31 is of a size and shape required to attach the tape 31 so that the electrode tabs 20 are gathered together in a state where the electrode tabs 20 are gathered together. Meanwhile, the step (a) of cutting and preparing the tape 31 does not necessarily have to be performed first, and can be performed at any step as long as it is performed only before the step of taping the tape (c), which will be described below.

(b) The step of forming the electrode tab stack may be a step of forming the electrode tab stack 30 by gathering a plurality of electrode tabs 20. Figure 2(b) shows this step. This step can be performed using a tab guide 110 that gathers a plurality of electrode tabs 20 to form an electrode tab stack 30. Referring to (b) of FIG. 2, the tab guide 110 may come down from the upper and lower portions of the electrode tab 20 in the direction of the electrode tab 20 and bring the electrode tabs 20 together. The tab guide 110 may press or guide a plurality of electrode tabs 20 above and below the electrode tab 20 to gather the electrode tabs 20 to form the electrode tab stack 30.

And, the end of the tab guide 110 may have a round shape. This shape can prevent damage to the electrode tabs 20 while the tab guide 110 applies pressure to the plurality of electrode tabs 20 from above and below to collect them.

(c) The step of taping the tape may be a step of taping the tape 31 to the electrode tab laminate 30. This step may be a step in which the collected electrode tab stack 30 maintains a stable shape without moving or being disturbed. This may be to gather the electrode tabs 20 to facilitate welding in the later welding step of the electrode lead 40.

Figure 2(c) shows this step. And FIG. 4 shows a state in which the tape 31 is attached to the electrode tab stack 30 in step (c). Referring to Figure 2 (c) and Figure 4, in the taping step (c), based on the width direction (W) of the electrode tab stack 30, the tape 31 is aligned with the electrode tab stack 30. ) can be attached to both ends of the. And while being attached to both ends, the tape 31 may be attached while surrounding the top, side, and bottom surfaces of the electrode tab stack 30. The electrode tabs 20 may be attached in a taut state with tension applied to tightly bring them together, or may be attached with appropriate strength so as not to be too tight. Referring to FIG. 4, the tape 31 may be attached to a horizontal portion of the portion where the electrode tabs 20 are gathered, and may also be partially attached to an inclined portion extending from the horizontal portion toward the electrode assembly.

And, in the (c) taping step, the tape 31 may be attached to the upper or lower surface of the electrode tab stack 30, but may not be attached to the portion where the electrode lead 40 is to be welded. In this way, a welding area A where the electrode lead 40 is welded may be formed in the portion where the tape 31 is not attached (see FIG. 6). Since the area where the tape 31 is located is an unsuitable surface for welding, the tape 31 may not be attached to the surface to be welded. When attaching the tape 31, the tape attacher 120 can be used to tape the cut tape 31 to the electrode tab laminate 30.

Here, the basic function of the tape applicator 120 may be to attach the cut tape 31 to the electrode tab 20, but the tape applicator 120 may also be configured to have the function of cutting the tape 31. there is. In this case, the tape applicator 120 can also function as a tape cutting unit. When using the tape applicator 120, which has the function of a tape cutting unit, the work can be simplified and efficient. In other words, after completing cutting the tape 31, holding the tape 31 as is without the need to move it to another location and then attaching it to the electrode tab 20 can result in significantly more efficient work.

Meanwhile, steps (b) and (c) can be carried out separately, but can also be carried out together. In other words, a more efficient and effective process may be possible if the steps of (b) forming the electrode tab stack and (c) taping the tape are performed simultaneously. That is, as shown in Figure 3 (c), the tab guide 110 presses the electrode tabs 20, gathers them, and fixes them, and the tape applicator 120 collects the tapes 31 into the collected electrode tab stack ( 30), more accurate taping may be possible.

(d) The step of welding the electrode tab stack and the electrode lead may be a step of welding the taped electrode tab stack 30 and the electrode lead 40 overlapping each other using a welder. This may be a step of joining the electrode tab stack 30 and the electrode lead 40 by welding. And specifically, the step (d) of welding the electrode lead 40 may be a step of laser welding the electrode tab stack 30 and the electrode lead 40 by laser welding. Figure 2(d) shows this step. This step can be performed using a laser welder 130, which is a device that irradiates a welding laser to the electrode tab stack 30 and the electrode lead 40.

The state in which the electrode lead 40 is joined to the electrode tab stack 30 by laser welding is shown in FIG. 6 . Referring to FIG. 6, the welding area A where laser welding is performed may be an area where the tape 31 is not attached. That is, as shown in FIG. 6, the welding area A may be the central area of the upper surface of the electrode tab stack 30. Of course, the electrode lead 40 is not limited to being welded to the upper surface of the electrode tab stack 30, and the electrode lead 40 may also be welded to the lower surface of the electrode tab stack 30.

In this way, according to the secondary battery manufacturing method and manufacturing device according to Example 1 of the present invention, unlike the conventional pre-welding method, the tape 31 is used, so secondary battery manufacturing can proceed without damaging the electrode tab 20. . And since ultrasonic welding itself is not performed, problems such as welding defects caused by ultrasonic welding can be fundamentally solved. For example, welding defects due to deviation in the horizontality of the horn and anvil or lamination abnormalities during welding, and disconnection defects in the electrode tab 20 may not occur. Of course, since ultrasonic welding is not used, various problems caused by using an ultrasonic welder may not occur.

When using the method of gathering the electrode tabs 20 using the tape 31 according to Example 1 of the present invention, the electrode tabs 20 are gathered quickly and efficiently to form the electrode lead 40 and the electrode tab ( 20) The main welding can be facilitated efficiently. In addition, by gathering the electrode tabs 20, the length margin of the electrode tabs 20 can be well secured.

Also, in the main welding step, when the electrode lead 40 overlaps the electrode tab 20, the edge of the electrode lead 40 touches the electrode tab 20, thereby reducing the problem of damage to the electrode tab 20. . Since the tape 31 covers and protects the surface of the electrode tab 20, damage may not occur even if the edge touches that area. In addition, it is possible to prevent the problem of marks on the electrode tab 20 caused by the laser mask jig during laser welding.

Meanwhile, Embodiment 1 of the present invention may be implemented in an additional modified form. Figure 3 is a side view showing the process of connecting the electrode tab 20 and the electrode lead 40 according to a modification of Embodiment 1 of the present invention.

Referring to FIG. 3, a modification of Example 1 of the present invention may further include a cutting step (c-1) between steps (c) and (d).

Specifically, the cutting step (c-1) may be a step of cutting one end of the taped electrode tab stack 30. Figure 3(c-1) shows this step. In a modified example of Example 1 of the present invention, the remaining steps are the same as Example 1 of FIG. 2, except that between (c) taping the tape and (d) welding the electrode tab laminate and the electrode lead. (c-1) The difference is that it further includes a cutting step. (c-1) The cutting step can be performed using the cutter 140, which cuts one end of the electrode tab stack 30 for which taping has been completed by the tape applicator 120 to an appropriate length. can do.

When the electrode tab stack 30 is cut to an appropriate length, the efficiency of laser welding work can be increased by making it to an appropriate length for subsequent laser welding. In addition, there is an effect of being able to adjust the length of the electrode tab stack 30 to suit the final secondary battery product size. Even at this time, the method of fixing the electrode tab 20 with the tape 31 of the present invention can fix the electrode tab 20 so that cutting the electrode tab 20 is easy.

In Figure 5, one end of the electrode tab stack 30 is cut by the cutter 140. In Figure 5, the electrode tab stack 30 is shown to be neatly cut along the cutting line L. In FIG. 5 , the central area of the upper surface of the electrode tab 20 where the tape 31 is not attached may be the laser welding area A where the electrode lead 40 is welded. After the cutting operation, welding can be performed accurately in this welding area (A).

Meanwhile, a secondary battery manufacturing apparatus may be required to perform the secondary battery manufacturing method according to Example 1 of the present invention. This secondary battery manufacturing apparatus may be a secondary battery manufacturing apparatus that welds a plurality of electrode tabs 20 extending from one end of the electrode assembly 10, which is formed by stacking electrodes and separators, to the electrode lead 40.

The secondary battery manufacturing device for performing the secondary battery manufacturing method according to Example 1 of the present invention may be a tape cutting unit (not shown), a tab guide 110, a tape applicator 120, and a laser welder 130.

The tape cutting unit may be configured to cut the tape 31 into a required size and shape. The tab guide 110 may be configured to gather a plurality of electrode tabs 20 to form an electrode tab stack 30. The tape attacher 120 may be configured to tape the cut tape 31 to the electrode tab stack 30. Additionally, the laser welder 130 may be configured to weld the taped electrode tab stack 30 and the electrode lead 40. Here, the tape applicator 120 can also function as a tape cutting unit. And according to the modified example of Example 1 of the present invention, the secondary battery manufacturing apparatus further includes a cutter 140 for cutting one end of the electrode tab stack 30 on which taping has been completed by the tape applicator 120. can do.

Example 2

Figure 6 is a perspective view showing the internal shape of a secondary battery according to Example 2 of the present invention.

Example 2 of the present invention is different from Example 1 in that it relates to a secondary battery manufactured by the secondary battery manufacturing method of Example 1.

Contents in common with Example 1 will be omitted as much as possible and Example 2 will be described focusing on the differences. In other words, it is obvious that if content not explained in Example 2 is necessary, it can be supplemented through the content of Example 1.

Referring to FIG. 6, the secondary battery according to Example 2 of the present invention may include an electrode assembly 10, a pouch, an electrode tab stack 30, an electrode lead 40, and a tape 31.

The electrode assembly 10 may be a laminate formed by stacking electrodes and separators. The pouch (not shown) may be configured to accommodate the electrode assembly 10 in an internal space. The electrode tab stack 30 extends from one end of the electrode assembly 10 and may be formed by gathering a plurality of electrode tabs 20 located inside the pouch. The tape 31 may be configured to surround the electrode tab stack 30. Here, the tape 31 may be attached to both ends of the electrode tab stack 30 based on the width direction (W) of the electrode tab stack 30.

When attached to both ends, the tape 31 may be attached while surrounding the top, side, and bottom surfaces of the electrode tab stack 30. The electrode tabs 20 may be attached in a taut state with tension applied to tightly bring them together, or may be attached with appropriate strength so as not to be too tight. Based on the side view, the tape 31 may be attached to a horizontal portion of the portion where the electrode tabs 20 are gathered, and may also be partially attached to an inclined portion extending from the horizontal portion toward the electrode. In other words, the thickness of the electrode tab stack 30 may be constant in the horizontal portion but may become thick in the inclined portion, and the tape 31 may be attached to some of the horizontal portion and the inclined portion.

Additionally, the tape 31 may not be attached to the upper and lower surfaces of the electrode tab stack 30 where the electrode lead 40 is to be welded. In this way, a welding area A where the electrode lead 40 is welded may be formed in the portion where the tape 31 is not attached (see FIG. 6). Since the area where the tape 31 is attached will be an unsuitable surface for welding, the tape 31 is not attached to the surface to be welded.

The electrode lead 40 may have one side connected to the electrode tab stack 30 and the other side protruding to the outside of the pouch (not shown). One side of the electrode lead 40 may be connected to the electrode tab stack 30 in the welding area A through laser welding. And welding can be performed excluding the area where the lead film 41 will be attached.

In addition, the secondary battery according to Example 2 of the present invention as described above may be a secondary battery of excellent quality as various effects of the invention described in Example 1 above are expressed.

Example 3

Figure 7 is a side view showing a process of connecting an electrode tab and an electrode lead by the secondary battery manufacturing method according to Example 3 of the present invention. Figure 8 is a perspective view showing a state in which a tape is attached to an electrode tab laminate in Example 3 of the present invention. Figure 9 is a cross-sectional view showing the principle by which the surplus portion of the tape is created in Embodiment 3 of the present invention. Figure 10 is a perspective view showing a state in which one end of the electrode tab laminate is cut in Example 3 of the present invention.

Example 3 differs from Examples 1 and 2 in that when attaching the tape to the electrode tab laminate, the tape is attached so that surplus portions are formed on both sides of the electrode tab.

Contents in common with Examples 1 and 2 will be omitted as much as possible and Example 3 will be described focusing on the differences. In other words, it is obvious that if content not explained in Example 3 is necessary, it can be supplemented through the content of Examples 1 and 2.

Referring to FIG. 7, the secondary battery manufacturing method according to Example 3 of the present invention also involves attaching a plurality of electrode tabs 20 extending from one end of the electrode assembly 10, which is formed by stacking electrodes and separators, to the electrode lead 40. It may be related to a welding secondary battery manufacturing method.

The electrode assembly 10 is formed by alternately stacking electrodes and separators, and the electrode tab 20 may be a metal tab connected to the electrode and protruding from one side of the electrode. Accordingly, the plurality of electrode tabs 20 may have a structure extending from one end of the electrode assembly 10. A secondary battery can be manufactured by combining the plurality of electrode tabs 20 and combining them again with the electrode lead 40.

The secondary battery manufacturing method according to Example 3 of the present invention includes (a) preparing a tape, (b) forming an electrode tab laminate, (c) taping the tape, and (d) electrode lead. It may include the step of welding.

Of course, in Example 3, a cutting step (c-1) may be further included between steps (c) and (d).

Steps (a) and (b) of FIG. 7 may be the same as those previously described in Example 1.

(c) The step of taping the tape may be a step of taping the tape 31 to the electrode tab laminate 30. This step may be a step in which the collected electrode tab stack 30 maintains a stable shape without moving or being disturbed. This may be to gather the electrode tabs 20 to facilitate welding in the later welding step of the electrode lead 40.

Figure 7(c) shows this step. And FIG. 8 shows a state in which the tape 31 is attached to the electrode tab stack 30 in step (c). Referring to Figure 7 (c) and Figure 8, in the taping step (c), based on the width direction (W) of the electrode tab stack 30, the tape 31 is aligned with the electrode tab stack 30. ) can be attached to both ends of the.

In the secondary battery manufacturing method according to Example 3 of the present invention, the tape 31 is formed as an electrode so that a surplus portion 31-1 protrudes further outward than the end in the width direction (W) of the electrode tab stack 30. It can be attached to the tab stack 30.

In the cross-sectional view of FIG. 9, the principle by which the surplus portion 31-1 is created is shown. First, referring to the drawing to the left of the arrow in FIG. 9, the tape 31 is placed in the electrode tab laminated body 30 so that there is a portion remaining further outward than the end of the electrode tab based on the width direction (W) of the electrode tab laminated body 30. It can be attached by surrounding the side of 30). And after attaching the tape 31 in this way, the upper and lower tapes can be attached to each other by applying force (E1, E2) to the remaining outer portion from above and below. In this way, the shape of the tape can be formed as shown on the right side of the arrow in FIG. 9. Here, the surplus portion 31-1 is formed so that a part of the tape 31 located further outside the width direction end of the electrode tab laminate 30 and another part of the tape 31 are glued together. It can be.

In this way, the surplus portion 31-1 of the tape 31 can be created. When the formation of the surplus portion 31-1 is completed in this way, the electrode assembly can have the shape as shown in FIG. 8.

The electrode tabs 20 may be attached in a taut state with tension applied to tightly bring them together, or may be attached with appropriate strength so as not to be too tight. Referring to FIG. 8, the tape 31 may be attached to a horizontal portion of the portion where the electrode tabs 20 are gathered, and may also be partially attached to an inclined portion extending from the horizontal portion toward the electrode assembly.

In the taping step (c), the tape 31 may be attached to the upper or lower surface of the electrode tab stack 30, but may not be attached to the portion where the electrode lead 40 is to be welded. In this way, a welding area A where the electrode lead 40 is welded may be formed in a portion where the tape 31 is not attached (see FIG. 11). Since the area where the tape 31 is located is an unsuitable surface for welding, the tape 31 may not be attached to the surface to be welded. When attaching the tape 31, a tape attacher 120 that taps the cut tape 31 to the electrode tab laminate 30 can be used.

Here, the tape attacher 120 tapes the tape 31 to the electrode tab stack 30 and may be attached to the top, side, and bottom of the electrode tab stack 30. However, in Example 3 of the present invention, the tape applicator 120 tapes the tape 31 to the electrode tab laminate 30, but the surplus portion 31-1 protrudes further outward than the width direction end of the electrode tab. The tape 31 may be attached to the electrode tab stack 30 so that .

In addition, it may further include a clamping device 150 that pulls the surplus portions 31-1 located on both sides of the electrode tab laminated body to both sides based on the width direction (W) of the electrode tab laminated body 30. . This clamping device 150 can be mainly used in the step of welding the electrode lead 40, which will be described below, but can also be used in the taping step (c) to tightly attach the tape 31.

Meanwhile, steps (b) and (c) can be carried out separately, but can also be carried out together. In other words, a more efficient and effective process may be possible if the steps of (b) forming the electrode tab stack and (c) taping the tape are performed simultaneously.

Meanwhile, referring to FIG. 7, Embodiment 3 of the present invention may further include a cutting step (c-1) between steps (c) and (d).

Specifically, the cutting step (c-1) may be a step of cutting one end of the taped electrode tab stack 30. Figure 7(c-1) shows this step.

(c-1) The cutting step can be performed using the cutter 140, which cuts one end of the electrode tab stack 30 for which taping has been completed by the tape applicator 120 to an appropriate length. can do. In Embodiment 3 of the present invention, during the cutting step, the surplus portion 31-1 of the tape may also be cut.

When the electrode tab stack 30 is cut to an appropriate length, the efficiency of laser welding work can be increased by making it to an appropriate length for subsequent laser welding. In addition, there is an effect of being able to adjust the length of the electrode tab stack 30 to suit the final secondary battery product size. Even at this time, the method of fixing the electrode tab 20 with the tape 31 of the present invention can fix the electrode tab 20 so that cutting the electrode tab 20 is easy.

In Figure 10, one end of the electrode tab stack 30 is cut by the cutter 140. In FIG. 10, the electrode tab stack 30 and the excess portion 31-1 of the tape are cleanly cut along the cutting line L. In FIG. 10 , the central area of the upper surface of the electrode tab 20 to which the tape 31 is not attached may be the laser welding area A where the electrode lead 40 is welded. After the cutting operation, welding can be performed accurately in this welding area (A).

(d) The step of welding the electrode tab stack and the electrode lead may be a step of welding the taped electrode tab stack 30 and the electrode lead 40 overlapping each other using a welder. This may be a step of joining the electrode tab stack 30 and the electrode lead 40 by welding. And specifically, the step (d) of welding the electrode lead 40 may be a step of laser welding the electrode tab stack 30 and the electrode lead 40 by laser welding.

Figure 7(d) shows this step. This step can be performed using a laser welder 130, which is a device that irradiates a welding laser to the electrode tab stack 30 and the electrode lead 40.

And in Example 3 of the present invention, the step (d) of welding the electrode lead 40 involves holding the surplus portions 31-1 located on both sides of the electrode tab laminate 30 with the clamping device 150 and holding the electrode lead 40. The electrode tab stack 30 and the electrode lead 40 can be welded while pulling the tab stack 30 to both sides in the width direction (W) (see F1 and F2 in FIG. 7).

In this case, the gap between the electrode tabs 20 can be eliminated. That is, the electrode tabs 20 can be brought into closer contact. When welding is performed with tension applied in this way, the welding quality between the electrode tab stack 30 and the electrode lead 40 can be further improved.

When using the method of gathering the electrode tabs 20 using the tape 31 according to Example 3 of the present invention, the electrode tabs 20 are gathered quickly and effectively to form the electrode lead 40 and the electrode tab 20. ) can facilitate the main welding of the machine significantly and effectively.

Example 4

Figure 11 is a perspective view showing the internal shape of a secondary battery according to Example 4 of the present invention.

Example 4 of the present invention differs from Examples 1 to 3 in that it relates to a secondary battery manufactured by the secondary battery manufacturing method of Example 3.

Contents in common with Examples 1 to 3 will be omitted as much as possible, and Example 4 will be described focusing on the differences. In other words, it is obvious that if content not explained in Example 4 is necessary, it can be supplemented through the content of Examples 1 to 3.

Referring to FIG. 11, the secondary battery according to Example 4 of the present invention may include an electrode assembly 10, a pouch, an electrode tab stack 30, an electrode lead 40, and a tape 31.

The electrode assembly 10 may be a laminate formed by stacking electrodes and separators. The pouch (not shown) may be configured to accommodate the electrode assembly 10 in an internal space. The electrode tab stack 30 extends from one end of the electrode assembly 10 and may be formed by gathering a plurality of electrode tabs 20 located inside the pouch. The tape 31 may be configured to surround the electrode tab stack 30. Here, the tape 31 may be attached to both ends of the electrode tab stack 30 based on the width direction (W) of the electrode tab stack 30.

The tape 31 is attached to both ends of the electrode tab stack 30, and the tape 31 has a surplus portion 31-1 that protrudes further outward than the ends in the width direction (W) of the electrode tab stack 30. ) may include.

This surplus portion 31-1 has a form in which a part of the tape 31 located further outside the end in the width direction (W) of the electrode tab laminate 30 and another part of the tape 31 are glued together. You can have it. The tape 31 may be attached to the upper and lower surfaces of the electrode tab stack 30. Additionally, the tape may be attached to at least a portion of the side surface of the electrode tab stack 30 (see FIG. 9). As the tape 31 applies tension to the electrode tab stack 30, the electrode tabs 20 can be maintained in close contact.

Additionally, the tape 31 may be attached in a taut state with tension applied to tightly gather the electrode tabs 20, or may be attached with appropriate strength without being too tight. Based on the side view, the tape 31 may be attached to a horizontal portion of the portion where the electrode tabs 20 are gathered, and may also be partially attached to an inclined portion extending from the horizontal portion toward the electrode. In other words, the thickness of the electrode tab stack 30 may be constant in the horizontal portion but may become thick in the inclined portion, and the tape 31 may be attached to some of the horizontal portion and the inclined portion.

Additionally, the tape 31 may not be attached to the upper and lower surfaces of the electrode tab stack 30 where the electrode lead 40 is to be welded. In this way, a welding area A where the electrode lead 40 is welded may be formed in a portion where the tape 31 is not attached (see FIG. 11). Since the area where the tape 31 is attached will be an unsuitable surface for welding, the tape 31 is not attached to the surface to be welded.

The electrode lead 40 may have one side connected to the electrode tab stack 30 and the other side protruding to the outside of the pouch (not shown). One side of the electrode lead 40 may be connected to the electrode tab stack 30 in the welding area A through laser welding.

In addition, the secondary battery according to Example 4 of the present invention as described above may be a secondary battery of excellent quality as various effects of the invention described in Examples 1 and 3 above are expressed.

Although the present invention has been described above with limited examples and drawings, the present invention is not limited thereto, and the technical idea of the present invention and the following description will be provided by those skilled in the art in the technical field to which the present invention pertains. Various implementations are possible within the scope of equivalency of the patent claims.

10: Electrode assembly
20: electrode tab
30: Electrode tab laminate
31: tape
31-1: Surplus
40: electrode lead
41: lead film
110: Tap guide
120: Tape applicator
130: Laser welder
140: cutter
150: clamping device
L: cutting line

Claims (21)

In the secondary battery manufacturing method of welding a plurality of electrode tabs extending from one end of an electrode assembly formed by stacking electrodes and separators to an electrode lead,
(a) Preparing tape of the required size and shape;
(b) forming an electrode tab stack by gathering the plurality of electrode tabs;
(c) taping the tape to the electrode tab laminate; and
(d) welding the taped electrode tab stack and the electrode lead. In claim 1,
Between step (c) and step (d),
(c-1) A secondary battery manufacturing method further comprising a cutting step of cutting one end of the taped electrode tab laminate. In claim 1,
In the step (a) of preparing the tape,
A method of manufacturing a secondary battery, characterized in that the step of preparing the tape by cutting the tape into the required size and shape. In claim 1,
The step (b) of forming the electrode tab laminate is:
A method of manufacturing a secondary battery, characterized in that the plurality of electrode tabs are pressed or guided above and below the electrode tab to gather the electrode tabs to form an electrode tab stack. In claim 1,
In the taping step (c),
A secondary battery manufacturing method, wherein the tape is attached to both ends of the electrode tab stack based on the width direction of the electrode tab stack. In claim 5,
In the taping step (c),
The tape is a secondary battery manufacturing method, characterized in that it is attached while wrapping the top, side, and bottom of the electrode tab laminate. In claim 6,
In the taping step (c),
A secondary battery manufacturing method, characterized in that the tape is not attached to the portion where the electrode lead is to be welded on the upper and lower surfaces of the electrode tab laminate. In claim 1,
In the step (c) of taping,
The tape is attached to both ends of the electrode tab laminated body based on the width direction of the electrode tab laminated body,
A method of manufacturing a secondary battery, characterized in that attaching the tape to the electrode tab laminate so that a surplus portion protruding further outward than the width direction end of the electrode tab laminate is formed. In claim 8,
In the taping step (c),
A method of manufacturing a secondary battery, characterized in that the surplus portion is formed so that a part of the tape located further outside the width direction end of the electrode tab laminate and another part of the tape face each other and are adhered. In claim 1,
A secondary battery manufacturing method, characterized in that step (b) and step (c) are performed together. In claim 1,
In the step (d) of welding the electrode lead,
A secondary battery manufacturing method characterized by welding the electrode tab stack and the electrode lead by laser welding. In claim 11,
In the step (d) of welding the electrode lead,
Characterized in welding the electrode tab laminated body and the electrode lead while holding the surplus portion located on both sides of the electrode tab laminated body with a clamping device and pulling it to both sides based on the width direction of the electrode tab laminated body. Secondary battery manufacturing method. In the secondary battery manufacturing device for welding a plurality of electrode tabs extending from one end of an electrode assembly formed by stacking electrodes and separators to an electrode lead,
A tape cutting unit that cuts the tape into the required size and shape;
a tab guide that gathers the plurality of electrode tabs to form an electrode tab stack;
a tape attacher for taping the tape cut to the electrode tab laminate; and
A secondary battery manufacturing device comprising a laser welder for welding the taped electrode tab stack and the electrode lead. In claim 13,
The tape attacher tapes the tape to the electrode tab laminate,
A secondary battery manufacturing device, characterized in that it is attached while surrounding the top, side, and bottom of the electrode tab laminate. In claim 13,
The tape attacher tapes the tape to the electrode tab laminate,
A secondary battery manufacturing apparatus, characterized in that the tape is attached to the electrode tab laminate to form a surplus portion that protrudes further outward than the width direction end of the electrode tab. In claim 15,
A secondary battery manufacturing apparatus further comprising a clamping device that pulls the surplus portions located on both sides of the electrode tab laminated body to both sides based on the width direction of the electrode tab laminated body. In claim 13,
A secondary battery manufacturing apparatus further comprising a cutter for cutting one end of the electrode tab laminate on which taping has been completed by the tape attacher. An electrode assembly formed by stacking an electrode and a separator;
a pouch accommodating the electrode assembly in an internal space;
an electrode tab stack formed by gathering a plurality of electrode tabs extending from one end of the electrode assembly and located inside the pouch;
Tape surrounding the electrode tab laminate; and
A secondary battery comprising: an electrode lead on one side connected to the electrode tab stack and on the other side protruding to the outside of the pouch. In claim 18,
The tape is,
A secondary battery, characterized in that it is attached to both ends of the electrode tab stack based on the width direction of the electrode tab stack. In claim 18,
The tape is,
A secondary portion attached to both ends of the electrode tab laminated body based on the width direction of the electrode tab laminated body, and comprising a surplus portion that protrudes further outward than the ends in the width direction (W) of the electrode tab laminated body. battery. In claim 20,
A secondary battery, characterized in that the surplus portion has a form in which a part of the tape located further outside an end in the width direction (W) of the electrode tab laminate is adhered to another part of the tape facing each other.

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