KR102117446B1 - Scroll-Typed Welding Member Having Electrode Tab Mounted thereon - Google Patents

Abstract

The present invention is a welding member for welding an external electrode tab to a cylindrical battery cell, and connects a plurality of tab seating portions of an upwardly open structure, welding electrode tabs mounted on each of the tab seating portions, and the tab seating portions. It consists of a structure including a connecting portion, the through-hole for welding is drilled in the lower center of the tab seating portion, the welding member characterized in that it is made of a roll-shaped structure that is taken out (unwind) from one end portion Provides

Description

{Scroll-Typed Welding Member Having Electrode Tab Mounted thereon}

The present invention relates to a rolled welding member equipped with an electrode tab.

With the development of technology and demand for mobile devices, the demand for secondary batteries is also rapidly increasing. Among them, lithium secondary batteries with high energy density, operating voltage, and excellent storage and lifespan characteristics are not only used for various mobile devices but also various electronic products. It is widely used as an energy source.

According to the shape of the battery case, such a lithium secondary battery includes a cylindrical battery and a square battery in which the electrode assembly is embedded in a cylindrical or square metal can, and a pouch type in which the electrode assembly is embedded in a pouch-shaped case of an aluminum laminate sheet. It is classified as a battery. Among them, the cylindrical battery has the advantage of being relatively large in capacity and structurally stable.

The electrode assembly embedded in the battery case is a power generator capable of charging and discharging consisting of a stacked structure of a positive electrode / separator / negative electrode, a jelly-roll type wound through a separator between a long sheet-shaped positive electrode and a negative electrode coated with an active material, and a predetermined It is classified into a stack type in which a plurality of anodes and cathodes of a size are sequentially stacked with a separator interposed therebetween. Among them, the jelly-roll electrode assembly has advantages of easy manufacturing and high energy density per weight.

In recent years, as the shape of the device has been diversified, a long and slender ultra-compact secondary battery has been developed, and the jelly-roll electrode assembly is formed in a cylindrical battery case.

In order to connect the ultra-compact secondary battery with an external device, it is necessary to connect the electrode terminal of the battery cell and the external electrode tab, and the connection of the electrode tab is made by welding or the like, and the welding method is ultrasonic welding, resistance welding or laser. Welding or the like can be used.

However, since the size of the battery cell is very small, the size of the battery cell is very small, and thus, after fixing the battery cell, the tab is damaged in the process of adjusting the position of the tab on the electrode terminal and correcting the angle, and in the process of transporting the tab and contacting the electrode with the tab There is a problem that increases the likelihood of becoming.

In addition, it is difficult to respond flexibly when the design of the external tap is changed, and it is necessary to prevent contamination during welding and to manage it.

Therefore, there is a high need for a technology that can fundamentally solve these problems.

The present invention aims to solve the problems of the prior art as described above and the technical problems requested from the past.

The inventors of the present application have undergone in-depth studies and various experiments, and as described later, include electrode tabs for welding mounted on the tab seats of the upwardly open structure, and a connection portion connecting the tab seats When using a rolled welding member made of a structure, it is not necessary to separate the outer tab for welding, so it was found that the outer tab can be prevented from being damaged in the process of adjusting the position and angle of the outer tab. The invention has been completed.

The welding member according to the present invention for achieving this object is a welding member for welding an external electrode tab to a cylindrical battery cell, for welding mounted on each of the tab seating portions of the upwardly open structure and each of the tab seating portions It consists of a structure including an electrode tab and a connecting portion connecting between the tab seating portions, and a through hole for welding is perforated at a lower center of the tab seating portion, and a roll is taken out while unwinding from one end portion. It consists of a structure of the form.

As described above, when the electrode tab is welded to the electrode terminal of the battery case by using a rolled welding member in which a plurality of electrode tabs are wound in a state mounted on each of the tab seating portions, the fixed electrode tab and the electrode terminal Since welding is performed between the livers, it is possible to solve a problem in which a process of adjusting the position and angle of the electrode tabs is required by using the electrode tabs in a separated state. In addition, in the prior art, the tabs were likely to be damaged in a series of processes in which the electrode tabs are taken out, contacted with the battery case, and pressurized to weld. However, the above problems occur because the electrode tabs fixed to the welding member are used. Can be prevented.

Moreover, a through hole for welding is perforated at the lower end of the tab seating portion, and the size of the through hole is a size corresponding to an electrode terminal portion for welding, so that contamination by foreign matters can be prevented during welding, and contamination is prevented. There is no need for maintenance to improve convenience.

The cylindrical battery cell may be an ultra-small battery cell having a very small diameter and a relatively long length, thereby forming an overall slender shape, for example, an average diameter of 3 mm to 10 mm and a height of 10 mm to 50 mm. It can be made of.

As described above, in the case of welding an external electrode tab to a battery cell of a very small and slender shape, since a greater difficulty is involved in fixing the battery cell and positioning the electrode tab, when using a welding member having the above structure, the process You can solve your difficulties.

The welding method does not need to specifically limit the method, as long as it can maintain a stable bonding strength between the electrode terminal and the electrode tab, but considering that it is a welding for an ultra-small battery cell, it is preferable to use laser welding capable of precise welding. Do.

However, since the size of the electrode terminal is very small in the case of an ultra-small battery cell, the position of the electrode tab may be moved during the welding process. Accordingly, a side wall of the connection portion adjacent to the tab seating portion may be formed to prevent separation of the electrode tab in the welding process.

In one specific example, since the electrode tab mounted on the welding member is a structure separated from the welding member after being welded to the battery cell, there is a slight gap between the tab seating portion and the tab to facilitate separation of the electrode tab. It is preferred. Therefore, the width of the tab seating portion in the longitudinal direction of the welding member may be a structure that is relatively larger than the width of the electrode tab. In addition, the length of the tab seating portion which is in contact with the width of the electrode tab seating portion perpendicularly may be the same as the length of the electrode tab positioned in parallel with this, or may have a relatively long structure.

On the other hand, the depth of the tab seating portion may be formed larger than the thickness of the electrode tab to stably position the electrode tab. In addition, when the depth of the tab seating portion is formed too deep, the contact between the electrode terminal of the battery cell and the electrode tab is difficult, and the depth of the tab seating portion is relatively higher than the height of the protruding electrode terminal of the battery cell. It can be formed as small.

At the bottom of the tab seating portion, the portion except for the through hole needs to be prevented from being damaged by the non-welded portion of the battery cell during welding, and the thickness of the tab seating portion may be 0.01 mm to 0.2 mm, in detail 0.05 mm to 0.01 mm. When the thickness of the tab seating portion is less than 0.01 mm, stability may be a problem during welding, and when it is thicker than 0.2 mm, when the welding member of the same length is wound in a roll form, the overall thickness increases, so storage and management may be difficult. It is not desirable.

In one specific example, the through-hole formed in the lower center of the tab seating portion, in the process of welding after fixing the battery cell to the tab seating portion so that the electrode terminal is located in the through-hole, facilitates the position management of the electrode terminal and the through-hole In order to be formed in the same portion of the tab seating portion, the through-hole may be formed parallel to the longitudinal direction of the welding member.

On the other hand, considering that the electrode tab is located between the battery cell and the through hole, the welding portion of the electrode terminal is not visible in the welding direction. For ease of welding, the size of the through hole is the welding portion where the electrode terminal of the battery cell is located. It may be formed to be relatively large, and may be formed to be relatively smaller than the width of the electrode tab to prevent the electrode tab from coming through the through hole.

The electrode terminal may be a negative electrode terminal or a positive electrode terminal of the battery cell, and without moving the position of the battery cell, welding may be performed on both the negative electrode terminal and the positive electrode terminal while the battery cell is fixed, or Alternatively, after welding the electrode tab to any one of the negative electrode terminals, after moving the battery cell so that the remaining electrode terminals are positioned on the through hole, welding may be performed on the remaining electrode terminals.

In one specific example, the electrode tab mounted on the tab seating part is detached from the welding member after being attached to the battery cell, and is not reused after mounting the new electrode tab on the tab seating part again. That is, since the welding member is a disposable, there is no need for separate maintenance to prevent contamination of the tab seating portion from which the electrode tab is detached.

The present invention provides a battery cell manufactured using the welding member, and a battery pack including the battery cell.

Specifically, the battery pack may be used as a power source for devices requiring high temperature safety, long cycle characteristics, high rate characteristics, and the like, and detailed examples of such devices include mobile devices and wearable devices. ), A notebook computer, a smart pad, or a desk-top computer, but is not limited thereto.

Since the structure of these devices and their manufacturing method are known in the art, detailed descriptions thereof are omitted herein.

The present invention also provides a method for welding a cylindrical battery cell using the welding member, specifically, the battery cell welding method

(a) placing the battery cell in the tab seating portion so that the electrode terminal of the battery cell contacts the electrode tab;

(b) the process of fixing the battery cell with a gripper;

(C) the process of pressing the fixed battery cell toward the electrode tab; And

(d) The process of welding the electrode tab to the electrode terminal of the battery cell through the through hole of the tab seating portion.

The cylindrical battery cell has a very small diameter and a long length, and may be a structure having a thin shape as a whole. Therefore, a process of fixing the battery cell is required for stable welding. In addition, a process of pressing the battery cell in the direction of the electrode tab is necessary to increase the adhesion of the weld.

The process (b) and the process (c) may be performed sequentially using a gripper and a pressing member, respectively, of independent structures, or, for example, a battery composed of a structure surrounding an outer surface excluding the electrode terminal forming portion of the battery cell In the case where a member capable of simultaneously fixing and pressing the cell is used, steps (b) and (c) may be performed simultaneously.

In one specific example, the process (d) is a case in which the size of the through hole includes only one electrode terminal of the positive electrode terminal or the negative electrode terminal, and welding is performed to either of the positive electrode terminal or the negative electrode terminal. And, after releasing the pressure of the battery cell, by moving and repressurizing the battery cell so that the other electrode terminal and the through-hole coincide, welding to the other electrode terminal can be made, the through-hole and the anode terminal or the cathode It may include adjusting the position of the battery cell to match the position of the terminal.

In another specific example, the process (d) is a case in which the size of the through hole is formed to be large enough to include both the positive electrode terminal and the negative electrode terminal forming portion, and the battery cells are moved to match the electrode terminals and the through hole. Without welding, welding may be performed on each of the positive and negative terminals of the battery cell while the battery cell is fixed.

As described above, the welding member according to the present invention has a structure in which an external electrode tab is mounted on a tab seating part, and welding of the battery case is performed using the fixed electrode tab, and thus, a separate electrode tab is separated. Since it is not used, it is possible to omit the process of adjusting the position of the tab with respect to the electrode terminal and the process of transferring the tab, thereby preventing damage to the electrode tab.

In addition, since welding is performed through a through hole drilled in a lower portion of the tab seating portion, portions except for the electrode terminal of the battery cell are covered by the tab seating portion, thereby preventing contamination of foreign matter and convenience of maintenance during welding.

1 is a perspective view of a welding member according to one embodiment as viewed from the top;
2 is a schematic side view of the welding member of FIG. 1;
3 is a schematic side view showing a state in which the battery cell is located in FIG. 2;
4 is a schematic side view showing a state in which the battery cell of FIG. 3 is pressed;
5 is a schematic plan view of the welding member of FIG. 1;
6 is a perspective view of the welding member of FIG. 1 when viewed from the bottom;
7 is a schematic bottom view of the welding member of FIG. 1;
8 is a schematic view showing a part of the welding member of FIG. 1 according to one embodiment and a state in which the battery cell is fixed, pressed, and welded; And
9 is a schematic view showing a part of the welding member of FIG. 1 according to another embodiment and a state in which the battery cell is fixed, pressed, and welded.

Hereinafter, with reference to the drawings according to an embodiment of the present invention, it is for easier understanding of the present invention, and the scope of the present invention is not limited thereto.

1 schematically shows a perspective view of a welding member according to the present invention as viewed from above, and FIG. 2 schematically shows a side view of the welding member.

Referring to Figures 1 and 2, the welding member is a structure in the form of a roll of one side end (not shown) is wound, the welding is made sequentially from the other end portion 110 is unrolled, in Figure 1 3 The tab tab seating is shown.

Specifically, the welding member includes the tab seats 111, 121, and 131 of the upwardly open structure, the electrode tabs 131, 132, and 133 for welding mounted on the tab seats 111, 112, and 113, and tabs It includes connecting parts (141, 142, 143, 144) connecting between the seating parts (111, 112, 113).

In the center of the bottom (121, 122, 123) of the tab seating parts (111, 112, 113), a through hole (not shown) for welding is perforated, and the tab seating is provided at the connecting parts (141, 142, 143, 144). Sidewalls 151, 152, 153, 154, 155, and 156 are formed at a portion adjacent to the portion to prevent the electrode tab from being detached during the welding process.

The side walls 151, 152, 153, 154, 155, and 156 are narrower than the width of the connection portion and are shown at a height corresponding to the depth of the tab seating portion, but with the purpose of preventing the electrode tab from being detached and the roll-shaped welding. Considering that it is a member, the width of the side wall is preferably narrower than the width of the connecting portion, and may be a structure in which a plurality of pillars having a shape protruding upward with respect to the connecting portion are spaced apart. In addition, considering the depth of the tab seating portion, the height of the sidewalls may be relatively low when the tab seating portion is deep, or relatively high when the tab seating portion is low.

Each of the tab seating portions 111, 112, and 113 has electrode tabs 131, 132, and 133 mounted one by one, and the electrode tabs 131, 132, 133 are welded to the battery cell and then detached from the welding member. do. Thus, for easy separation of the electrode tabs, the width w2 of the tab seating portion is formed relatively larger than the width w1 of the electrode tabs 131, 132, and 133.

3 schematically shows a state in which the battery cell is located in the welding member of FIG. 2, and FIG. 4 schematically shows a state in which the battery cell in FIG. 3 is pressed.

3 and 4, the battery cells 181, 182, 183 are positioned in a state perpendicular to the ground so that the electrode terminals 191, 192, 193 contact the electrode tabs 131, 132, 133. , On the opposite surface of the surface where the electrode terminals of the battery cells are formed, the pressing members 191, 192, and 193 press the battery cells in the direction of the arrow, so that the electrode terminals and the electrode tabs of the battery cells can be brought into close contact. Therefore, through the through-hole (not shown) formed in the center of the tab seating portion (121, 122, 133), the electrode tab (131, 132, 133) and the electrode terminals (191, 192, 193) to be welded to be combined. You can.

The tab seating portion is a structure that is opened upward, and consists of a structure that protrudes downward. The depth (a) of the tab seating portion is preferably larger than the thickness (b) of the electrode tabs (131, 132, 133) when considering stable seating of the electrode tabs (131, 132, 133). However, since the electrode terminals 191, 192, 193 and the electrode tab must be stably combined, the depth (a) of the tab seating portion is relatively smaller than the height of the electrode terminals 191, 192, 193 of the battery cell. Can be.

The battery cells 181, 182, and 183 are cylindrical battery cells having an average diameter of 3 mm to 10 mm and a size of 10 mm to 50 mm in height, and are generally composed of thin and elongated structures.

FIG. 5 schematically shows a plan view of the welding member of FIG. 1.

Referring to FIG. 5, the connecting portions connecting the tab seating portions 121, 122, and 123 are formed with side walls 151, 152, 153, 154, 155, and 156 at portions adjacent to the tab seating portions, respectively. Electrode tabs 131, 132, and 133 are mounted one by one on the tab seating portions 121, 122, and 123, and the width w1 of the electrode tabs 131, 132, and 133 is the width w2 of the tab seating portion. It is smaller, and the length a1 of the electrode tabs is shown smaller than the length a2 of the tab seating portion. However, the width w1 of the electrode tab is smaller than the width w2 of the tab seating portion, and the length a1 of the electrode tab may be formed to be the same as the length a2 of the tab seating portion.

6 schematically shows a perspective view of the welding member of FIG. 1 when viewed from the lower surface, and FIG. 7 schematically shows a bottom view of the welding member of FIG. 1.

Referring to FIGS. 6 and 7, one through-hole for welding 161, 162, and 163 is formed on the lower surface of each of the tab seats 121, 122, and 123, and through-holes 161, 162, Through 163), the lower surfaces of the electrode tabs 131, 132, and 133 located on the tab seating portion are exposed. Since welding can be performed toward the exposed electrode tab, convenience and efficiency of the process may be improved because a stably fixed electrode tab is used.

The shape of the through-holes 161, 162, and 163 is shown in a circular shape, but is not particularly limited as long as it is a suitable shape for welding the electrode tab to the battery cell, and may be, for example, an oval, polygonal or slit shape. Can be.

At this time, the through holes (161, 162, 163) formed in the center of the lower surface of the tab seating portion. The center of the through hole is made to come on a straight line parallel to the longitudinal direction of the welding member.

Since the position of the battery cell is not visible through the through-holes 161, 162, and 163, it is preferable that the size of the through-hole is formed to be relatively larger than the welded portion where the electrode terminal of the battery cell is located for easy welding. In this case, even if welding is performed on each of the positive electrode terminal and the negative electrode terminal, welding may be performed on different electrode terminals without moving the battery cell. In addition, it is preferable that the size of the through-hole is relatively smaller than the width of the electrode tab to prevent the electrode tab from escaping through the through-hole.

8 and 9 schematically show a state in which welding is performed by pressing a part of the welding member of FIG. 1 and a battery cell fixed thereto.

Referring to FIG. 8, the battery cell 281 is positioned in a state perpendicular to the ground so that the electrode terminal 282 comes into contact with the electrode tab 231, as shown in the battery cells 181, 182, and 183 of FIG. 3, On the opposite surface of the surface where the electrode terminals 282 of the battery cells are formed, the pressing member 291 presses the battery cell in the direction of the arrow, and a fixing member 292 for fixing the position and angle of the battery cell is provided. It supports the side.

As described above, in the case where the pressing member 291 and the fixing member 292 are separated, the process of fixing the battery cell and the process of pressing are sequentially performed.

Referring to FIG. 9, the battery cell 381 is positioned in a state perpendicular to the ground so that the electrode terminal 382 contacts the electrode tab 331 as in the battery cells 181, 182, and 183 of FIG. 3, A pressure member 391 having a structure surrounding a side surface including an end of the battery cell fixes the battery cell to the opposite surface of the surface where the electrode terminal 382 of the battery cells is formed, while pressing the battery cell in the direction of the arrow.

As described above, when the pressing member 391 simultaneously serves to fix the battery cell, the fixing process and the pressing process of the battery cell may be simultaneously performed. Therefore, it is possible to reduce the type of member required for the welding process, and also to shorten the welding time, thereby improving productivity.

Those skilled in the art to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above.

Claims (18)

As a welding member for welding the external electrode tab to the cylindrical battery cell,
It consists of a structure including a plurality of tab seating portions of the upwardly open structure, electrode tabs for welding mounted on each of the tab seating portions, and a connecting portion connecting between the tab seating portions;
A through-hole for welding is drilled in the lower center of the tab seating portion;
A welding member characterized in that it is made of a roll-shaped structure that is taken out while unwinding from one end portion. The welding member according to claim 1, wherein the cylindrical battery cell has a size of an average diameter of 3 mm to 10 mm and a height of 10 mm to 50 mm. The welding member according to claim 1, wherein the welding is laser welding. The welding member according to claim 1, wherein a side wall of the connection portion adjacent to the tab seating portion is formed with a side wall for preventing separation of the electrode tab in the welding process. The welding member according to claim 1, wherein the width of the tab seating portion in the longitudinal direction of the welding member is relatively larger than the width of the electrode tab. The welding member according to claim 1, wherein the depth of the tab seating portion is greater than the thickness of the electrode tab. The welding member according to claim 1, wherein the depth of the tab seating portion is relatively smaller than the height of the protruding electrode terminal of the battery cell. The welding member according to claim 1, wherein the tab seating portion has a thickness of 0.01 mm to 0.2 mm. The welding member according to claim 1, wherein the through hole is formed parallel to the longitudinal direction of the welding member. The welding member according to claim 1, wherein the size of the through-hole is relatively larger than that of the welding portion where the electrode terminal of the battery cell is located and relatively smaller than the width of the electrode tab. The welding member according to claim 10, wherein the electrode terminal is a negative terminal or a positive terminal. The welding member according to claim 1, wherein the welding member is disposable. delete delete A method for welding a cylindrical battery cell using the welding member according to any one of claims 1 to 12,
(a) placing the battery cell in the tab seating portion so that the electrode terminal of the battery cell contacts the electrode tab;
(b) the process of fixing the battery cell with a gripper;
(C) the process of pressing the fixed battery cell toward the electrode tab; And
(d) Process of welding the electrode tab to the electrode terminal of the battery cell through the through hole of the top seat
Battery cell welding method comprising a. 16. The method of claim 15, wherein the process (b) and process (c) are performed simultaneously. 16. The method of claim 15, wherein the process (d) comprises adjusting the position of the battery cell such that the positions of the through-hole and the anode terminal or the cathode terminal coincide. The method of claim 15, wherein the process (d) is a battery cell welding method, characterized in that welding is performed on each of the positive and negative terminals of the battery cell while the battery cell is fixed.

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