KR-20260063512-A - TOP CAP WELDING APPARATUS OF CYLINDRICAL BATTERY CELL AND TOP CAP WELDING METHOD OF CYLINDRICAL BATTERY CELL USING THE SAME

KR20260063512AKR 20260063512 AKR20260063512 AKR 20260063512AKR-20260063512-A

Abstract

The present invention relates to a top cap welding device for a cylindrical battery cell and a top cap welding method for a cylindrical battery cell using the same, characterized by comprising: a conveying unit for conveying a cylindrical battery case containing an electrode assembly in which an electrode tab is exposed to the outside; a pressing unit located at the front of the battery case and pressing the battery case; a supporting unit located at the rear of the battery case and configured to support the battery case; a top cap holder for positioning a top cap at the rear of the electrode tab; a top cap supporting unit configured to support the rear of the top cap; and a welding unit that welds the electrode tab and the top cap while pressing the electrode tab against the top cap with a preset pressure.

Inventors

이수호
안종만

Assignees

주식회사 엘지에너지솔루션

Dates

Publication Date: 20260507
Application Date: 20241030

Claims (15)

A transfer unit for transferring a cylindrical battery case containing an electrode assembly in which the electrode tabs are exposed to the outside; A pressurizing part located at the front of the battery case and pressurizing the battery case; A support member located at the rear of the battery case and provided to support the battery case; A top cap holder positioning the top cap at the rear of the electrode tab; A top cap support member provided to support the rear of the top cap; and A top cap welding device for a cylindrical battery cell, characterized by including a welding portion that welds the electrode tab and the top cap while pressing the electrode tab against the top cap with a preset pressure.
In paragraph 1, The above welded part is, A welding mask provided to bring the electrode tab into close contact with the top cap; A welding mask support member that supports the above welding mask; A load sensor located on one side of the welding mask support and measuring the load value applied by the welding mask to the electrode tab; and A cylindrical battery cell top cap welding device characterized by including a fourth driving unit that drives the welding mask forward or backward.
In paragraph 2, The above welding mask support is, A second support block located on one side of the welding mask and supporting the welding mask; and A top cap welding device for a cylindrical battery cell, characterized by including a height adjustment part coupled to the upper part of the second support block and configured to adjust the upper and lower height of the second support block.
In paragraph 3, The second support block extends from one side of the welding mask and is provided in a shape in which one end extends upward. A top cap welding device for a cylindrical battery cell, characterized in that the height adjustment unit includes a height adjustment member connected to the upper end of the second support block to adjust the upper and lower height of the second support block.
In paragraph 3, The welding mask has a laser passage hole formed therein through which a laser for welding the electrode tab and the top cap passes. A top cap welding device for a cylindrical battery cell, characterized in that the second support block has a communication hole formed therein that communicates with the laser through hole.
In paragraph 5, A top cap welding device for a cylindrical battery cell, characterized in that the welding mask support further includes a shield gas injection unit located inside the welding mask to remove foreign substances generated during welding.
In paragraph 2, The above-mentioned pressurizing unit includes a support frame, and The above-mentioned fourth drive unit is, A fourth support plate fixed to the above support frame; A third guide rail provided on the upper side of the fourth support plate and configured to guide the linear movement of the welding mask; A third moving block coupled to the third guide rail and configured to enable reciprocating movement along the third linear movement section provided by the third guide rail; A fifth support plate connected to the third moving block; and A top cap welding device for a cylindrical battery cell characterized by including a connecting plate connected to the upper side of the fifth support plate and connected to one side of the load sensor.
In Paragraph 7, The above-mentioned fourth drive unit is, A third fixing member fixedly connected to the fourth support plate; and A second cylinder part; further including, A top cap welding device for a cylindrical battery cell, characterized in that the second cylinder part is connected between the connecting plate and the third fixing member and includes a second cylinder that provides forward or backward driving force to the welding mask, and a second housing that accommodates the second cylinder.
In paragraph 8, A top cap welding device for a cylindrical battery cell, characterized in that the second cylinder is connected to the third fixed member and transmits a forward driving force in the other direction to the connecting plate.
In paragraph 8, A top cap welding device for a cylindrical battery cell, characterized in that the welding portion further includes an air supply portion for injecting air into the internal space of the second housing.
In Paragraph 10, The internal space of the second housing is separated into space 2a and space 2a' by the second cylinder, and A top cap welding device for a cylindrical battery cell, characterized in that the air supply unit comprises a first air supply unit that supplies air to the seconda space and a second air supply unit that supplies air to the seconda' space.
In Paragraph 11, A top cap welding device for a cylindrical battery cell, characterized in that the second cylinder is driven back and forth by the air pressure difference between the seconda space and the seconda' space.
In paragraph 8, A second storage groove is formed on one side of the second housing, which is partially recessed inward. A top cap welding device for a cylindrical battery cell, characterized in that the above-mentioned fourth driving unit further includes a second position sensing sensor provided in the second receiving groove to detect the position of the welding mask.
In Paragraph 7, The above welding section further includes a fifth driving unit that drives the welding mask backward, and A third contact member located on the side of the fifth support plate and configured with a shape in which a portion of the rear extends downward; A third rotating block rotatably connected to the side of the support frame and configured to be in contact with a portion extending downward from the third contact member; and A top cap welding device for a cylindrical battery cell, characterized by including: a third rod member connected to one end of the third rotating block and configured to rotate the third rotating block by vertical driving.
A method for welding the top cap of a cylindrical battery cell using a top cap welding device for a cylindrical battery cell according to any one of claims 1 to 14, (S1) A step of transferring the battery case to one side or the other side through the transfer unit; (S2) A step of positioning the top cap at the rear of the electrode tab through the top cap holder; (S3) A step of supporting the rear of the top cap through the top cap support member; (S4) A step of pressing the battery case backward through the above-mentioned pressurizing part; and (S5) A step of welding the top cap and the electrode tab through the welded portion; characterized by a method for welding the top cap of a cylindrical battery cell.

Description

Top cap welding apparatus for a cylindrical battery cell and top cap welding method for a cylindrical battery cell using the same The present invention relates to a top cap welding device for a cylindrical battery cell and a top cap welding method for a cylindrical battery cell using the same. More specifically, it relates to a top cap welding device for a cylindrical battery cell and a top cap welding method for a cylindrical battery cell using the same, which can prevent welding defects when welding the electrode tab and the top cap of a cylindrical battery cell. With the increasing technological development and demand for mobile devices, rechargeable secondary batteries are being used as an energy source for various mobile devices. Secondary batteries are also attracting attention as an energy source for electric vehicles and hybrid electric vehicles, which are being presented as alternatives to conventional gasoline and diesel vehicles that use fossil fuels. Secondary batteries are classified according to the shape of the battery case into cylindrical and prismatic batteries, in which the electrode assembly is embedded in a cylindrical or prismatic metal can, and pouch-type batteries, in which the electrode assembly is embedded in a pouch-type case made of aluminum laminate sheets. Generally, cylindrical battery cells are used in which a jelly-roll type electrode assembly, wound with a separator sheet interposed between a positive electrode sheet and a negative electrode sheet, is housed in a cylindrical battery case. FIG. 1 is a cross-sectional view illustrating a cylindrical battery cell, and FIG. 2 is a drawing illustrating the appearance of an electrode tab of an electrode assembly welded to a top cap, viewed from the front and rear of the top cap. To manufacture a cylindrical battery cell, an electrode assembly is housed in an open cylindrical battery case, and a top cap is positioned at the top. A welding process is then performed to weld and connect the electrode tab of the electrode assembly to the top cap. In detail, the cylindrical battery cell (10) includes a battery case (11) with an open top, an electrode assembly (12) housed in the battery case (11), and a top cap (13) coupled to the top of the battery case (11). The top cap (13) is positioned on the upper part of the electrode assembly (12) and is electrically connected to the electrode tab (12a) of the electrode assembly (12), and is coupled to the upper open end of the battery case (11) to seal the electrode assembly (12) housed inside the battery case (11). The top cap (13) is electrically connected to the electrode tab (12a) through welding. The welding process is typically carried out with the battery case (11) containing the electrode assembly (12) being pressed toward the top cap (13) and the top cap (13) and the electrode tab (12a) in close contact. However, during the process of welding the electrode tab (12a) and the top cap (13), if the electrode tab (12a) and the top cap (13) do not come into close contact at a set position, the weld area may deviate from the focus of the laser beam, resulting in a weak weld. In addition, if the top cap (13) is pressed too hard, the CID (Current Interrupt Device) and safety vents that cut off current above a certain level may be damaged, causing the vents to operate below a certain level or failing to perform functions such as fire or explosion prevention. Figure 1 is a cross-sectional view illustrating a cylindrical battery cell. Figure 2 is a drawing illustrating the appearance of the electrode tab of the electrode assembly welded to the top cap, viewed from the front and rear of the top cap. FIG. 3 is a perspective view of a top cap welding device for a cylindrical battery cell according to the present invention, viewed from one side. FIG. 4 is a perspective view of a top cap welding device for a cylindrical battery cell according to the present invention, viewed from the other side. FIG. 5 is a top cap welding device for a cylindrical battery cell according to the present invention, viewed from above. FIG. 6 is a perspective view illustrating a pressurizing part constituting a top cap welding device for a cylindrical battery cell according to the present invention. FIG. 7 is a perspective view illustrating a transfer unit constituting a top cap welding device for a cylindrical battery cell according to the present invention. FIG. 8 is a drawing for explaining a pusher unit constituting a top cap welding device for a cylindrical battery cell according to the present invention, in which the supplied battery case is offset to one side. FIG. 9 is a drawing for explaining a pusher unit constituting a top cap welding device for a cylindrical battery cell according to the present invention, in which the supplied battery case is offset to the other side. FIG. 10 is an exploded cross-sectional view of a rotating shaft constituting a top cap welding device for a cylindrical battery cell according to