KR102242274B1 - Prismatic cell having current collector connecting structure and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a prismatic cell having a current collector connection structure and a manufacturing method thereof. According to one embodiment of the present invention, the method of manufacturing a prismatic cell having a current collector connection structure includes: a step (a) of preparing a jelly roll; a pre-welding step (b) of connecting the jelly roll with an electrode non-coating part; a main-welding step (c) of connecting the jelly roll completed with the pre-welding, with a current collector; and a prismatic cell assembly step (d) of storing the jelly roll completed with the main-welding, in a prismatic case, and then, assembling a cap plate including a plurality of electrode terminals so as to seal the prismatic case. The method also includes a step of connecting the current collector with the cap plate through spinning, after the step (c). Therefore, the present invention is capable of making a connection structure strong to impacts and vibrations.

Description

Prismatic cell having current collector connection structure and its manufacturing method {PRISMATIC CELL HAVING CURRENT COLLECTOR CONNECTING STRUCTURE AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a prismatic cell having a current collector connection structure and a method of manufacturing the same.

In general, a secondary battery refers to a battery capable of charging and discharging, unlike a primary battery that cannot be charged, and is widely used in electronic devices such as mobile phones, notebook computers, camcorders, or electric vehicles. In particular, lithium secondary batteries have a capacity of about three times that of nickel-cadmium batteries or nickel-hydrogen batteries in which operating voltages are widely used as power sources for various electronic equipment, and their utilization is rapidly increasing because the energy density per unit weight is high. .

Lithium secondary batteries mainly use lithium-based oxides and carbon materials as a positive electrode active material and a negative electrode active material, respectively. For example, a lithium secondary battery has an electrode assembly in which a positive electrode plate and a negative electrode plate to which a positive electrode active material and a negative electrode active material are applied, respectively, are disposed with a separator therebetween, and a battery case for sealing the electrode assembly together with an electrolyte.

And lithium secondary batteries are classified according to the shape of the battery case.

For example, there is a can-type secondary battery in which an electrode assembly is embedded in a metal can, and there is a pouch-type secondary battery in which the electrode assembly is embedded in a pouch. In particular, can-type secondary batteries are further classified into cylindrical secondary batteries (hereinafter referred to as cylindrical cells) and prismatic secondary batteries (hereinafter referred to as prismatic cells) according to the shape of the metal can.

The prismatic cell has a shape in which a plurality of stacked electrode assemblies are accommodated in the prismatic case. In addition, the prismatic cell includes a plurality of current collectors (eg, positive and negative current collectors, etc.) connected through the inside of the cap plate, that is, the rear portion of the cap plate assembled in the rectangular case.

In the case of a conventional prismatic cell, a method such as laser welding was mainly used to connect the current collector. However, according to this conventional method, when vibration is introduced from the outside or a physical shock is applied from the outside, there is a concern that the bonding of the welding part will be released. In addition, according to a conventional method such as laser welding, there is a problem in that the bonding is restricted in the case of different materials.

As a prior art related to the present invention, there is Korean Patent Publication No. 10-2015-0028068 (hereinafter, prior document), and the prior document discloses a prismatic battery cell. However, in the case of the prismatic battery cell disclosed herein, it is not suggested at all about the connection method of the current collector, which is resistant to vibration and shock, and does not have restrictions on bonding even in the case of heterogeneous materials.

It is an object of the present invention to provide a prismatic cell having an improved current collector connection structure that has a connection structure that is robust against vibration and shock, and does not have a connection restriction even in the case of a heterogeneous material, and a method of manufacturing the same.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention that are not mentioned can be understood by the following description, and will be more clearly understood by examples of the present invention. In addition, it will be easily understood that the objects and advantages of the present invention can be realized by the means shown in the claims and combinations thereof.

A method for manufacturing a prismatic cell having a current collector connection structure according to an embodiment of the present invention includes the steps of: (a) preparing a jelly roll; (b) a pre-welding step of connecting the jelly roll and the electrode uncoated portion; (c) a main-welding step of connecting the jelly roll on which the pre-welding has been completed and the current collector; And (d) assembling a cap plate having a plurality of electrode terminals to accommodate the jelly rolls on which the main welding has been completed in a prismatic case and to seal the prismatic case; and, the (c) After the step, connecting the current collector and the cap plate through a spinning process; further includes.

After the step (c), (c-1) inserting a protrusion protruding from the cap plate to a set length into the hole of the current collector to align the connection position of the current collector; (c-2) plastically deforming by spinning the protrusion head protruding through the hole of the current collector; And (c-3) connecting the current collector to the aligned position using the expanded cross-section of the protruding head part plastically deformed by the spinning process.

In the step (c-1), the hole may have a cross-sectional size equal to or greater than that of the protrusion and the protrusion head.

In the step (c-2), the protrusion head portion has a protrusion length greater than the thickness of the current collector, and when the protrusion is inserted into the hole, the protrusion may protrude to an upper portion of the current collector by a set length.

In the step (c-2), the spinning operation may be performed by a spinning apparatus including a spinning tool that rotates at high speed and a spinning body that provides rotational force to the spinning tool. The spinning operation includes a spinning tool that rotates at high speed, and a spinning body that provides rotational force to the spinning tool. The spinning tool rotates at high speed and is in contact with the protruding head to plastically deform the protruding head into an extended cross-sectional portion whose cross-section is expanded in the width direction. The spinning body provides rotational force to the spinning tool, adjusts the height of the spinning tool based on the protruding head, and within a set angle range so that the spinning tool has an inclined posture based on the central direction of the protruding head. It can be operated by tilting.

The expanded cross-sectional portion may have a shape for restricting a connection position by pressing the current collector connected to the protrusion with a predetermined force. Accordingly, the current collector can be prevented from being loosened or disconnected by vibration or external force without deformation due to thermal shock.

The expanded cross-sectional portion is deformed into a shape whose diameter is enlarged compared to the protruding head portion, but is deformed so that the upper surface is formed flat, or by the tilting control of the spinning device, the cross-section is deformed into a conical shape whose cross section is reduced upward. I can.

In addition, in the step (a), the jelly roll may be a stack type jelly roll in the form of a stack structure in which the electrode assemblies are stacked up and down, or a square wound type jelly roll.

In addition, after the step (c), folding the plurality of jelly rolls connected to each other to prepare a folding structure; further includes.

After the step (d), (e) further comprising the step of connecting the bus bar to the plurality of electrode terminals of the assembled prismatic cell by spinning.

The step (e) includes: (e-1) connecting the bus bar to each of the plurality of electrode terminals; (e-2) spinning the protruding heads of each of the plurality of electrode terminals protruding from the top of the bus bar to transform the protruding head into a deformable head that can pressurize the bus bar; And (e-3) a bus bar connection step of connecting each of the plurality of electrode terminals and the bus bar with a necessary coupling force by using the deformable head part.

In the step (e-1), the bus bar may have a through hole through which the electrode terminal passes through at least one end and is connected to each other.

In the step (e-2), the protruding head portion may have a shape extending outward from the center direction of the electrode terminal by a set length from the inner center of the electrode terminal and protruding from the inner center of the electrode terminal.

In addition, according to an embodiment of the present invention, there is provided a prismatic cell having a current collector connection structure manufactured by using a method of manufacturing a prismatic cell having a current collector connection structure. The prismatic cell includes a bus bar connected to each of the plurality of electrode terminals provided on one surface of the cap plate, and a current collector connected using the plurality of protrusions provided on the other surface of the cap plate, and the plurality of A bus bar connection structure that connects each of the plurality of electrode terminals and the bus bar using the plurality of deformable head portions by spinning the protruding head portion protruding from each of the electrode terminals of And plastically deformed by spinning a protrusion head protruding to each of the plurality of protrusions, and a current collector connection structure that connects each of the plurality of protrusions and the current collector using a cross-sectional extension shape of the protrusion head. have.

According to the present invention, the method and connection structure of connecting the electrode terminals of the square cell and the bus bar are improved, and the connection structure of the current collector constituting the square cell is reinforced, so that it is excellent in vibration and shock, and there are no restrictions even when using different materials. There is no advantage.

In addition to the above-described effects, specific effects of the present invention will be described together with explanation of specific matters for carrying out the present invention.

1 to 3 are flowcharts briefly showing a method of manufacturing a prismatic cell having a current collector connection structure and detailed steps thereof according to an embodiment of the present invention.
4 to 8 are process and conceptual diagrams for explaining a step of preparing a prismatic cell according to an embodiment of the present invention.
9 to 12 are process and conceptual diagrams illustrating a current collector connection step according to an embodiment of the present invention.
13 to 15 are process and conceptual diagrams for explaining the steps of connecting and connecting a bus bar according to an embodiment of the present invention.

The above-described objects, features, and advantages will be described later in detail with reference to the accompanying drawings, and accordingly, one of ordinary skill in the art to which the present invention pertains will be able to easily implement the technical idea of the present invention. In describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, a detailed description will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar elements.

Although the first, second, and the like are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are only used to distinguish one component from another component, and unless otherwise stated, the first component may be the second component.

Hereinafter, the "top (or bottom)" of the component or the "top (or bottom)" of the component means that an arbitrary component is arranged in contact with the top (or bottom) of the component. In addition, it may mean that other components may be interposed between the component and any component disposed on (or under) the component.

In addition, when a component is described as being "connected", "coupled" or "connected" to another component, the components may be directly connected or connected to each other, but other components are "interposed" between each component. It is to be understood that "or, each component may be "connected", "coupled" or "connected" through other components.

Throughout the specification, unless otherwise specified, each component may be singular or plural.

Singular expressions used in the present specification include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various elements or various steps described in the specification, and some of the elements or some steps It may not be included, or it should be interpreted that it may further include additional components or steps.

Throughout the specification, when referred to as "A and/or B", it means A, B or A and B, unless otherwise specified, and when referred to as "C to D", it means that a special opposite description is Unless there is one, it means that it is C or more and D or less.

Hereinafter, a prismatic cell having a current collector connection structure and a manufacturing method thereof according to some preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 to 3 are flowcharts briefly showing a method of manufacturing a prismatic cell having a current collector connection structure and detailed steps thereof according to an embodiment of the present invention.

Referring to FIG. 1, a method for manufacturing a prismatic cell according to an embodiment of the present invention includes a jelly roll preparation step (eg, a stack step) (S100), a pre-welding step (S200), a main welding step (S300), and a folding step. (S400), including a prismatic cell assembly step (S500). According to an embodiment of the present invention, after the main welding step (S300), the step of connecting the current collector and the cap plate by spinning (S310, S320, S330) is further included. And it may further include a bus bar connection connection step (S600) after the prismatic cell assembly step (S500).

Jelly Roll Preparation Step (or Stack Step)

The stacking step (S100), which is a step of preparing a jelly roll, is a step of making the stack structure 11 by stacking the electrode assemblies up and down (see FIG. 4). 4 shows an exemplary shape of a stack structure 11 according to an embodiment of the present invention. However, the illustrated stack structure 11 is a preferred exemplary shape, and the present invention is not necessarily limited to this shape, and may be implemented by changing various shapes that are obvious to a person skilled in the art. For example, unlike the stack type jelly roll shown in FIG. 4, a square-shaped winding type jelly roll may be provided, and in addition, various types of jelly rolls may be provided and used.

Pre-welding stage

The pre-welding step (S200) is a step of pre-welding the stack structure 11 (see FIG. 4) to connect the electrode uncoated portions of the jelly-roll 13 (see FIG. 5) (FIG. 5). 5 shows an exemplary shape of a jelly roll 13 according to an embodiment of the present invention. However, the illustrated jelly roll 13 is an exemplary shape, and the present invention is not limited to this shape, and may be implemented by changing into various shapes that are obvious to a person skilled in the art. For example, a square wound type jelly roll can be used.

Main welding stage

In the main welding step (S300), after the pre-welding step (S200) of the jelly roll 13 (see FIG. 5), a plurality of terminals and caps 15 (see FIG. 6), including the jelly roll 13 (see FIG. 5), This refers to welding the current collector, which is called main-welding.

Meanwhile, according to an embodiment of the present invention, the step of connecting the current collector and the cap plate by spinning may be performed after the main welding step S300, which will be described later.

Folding and square cell assembly steps

The folding step (S400) is a step of folding so that the plurality of jelly rolls 13 connected to both sides face each other and overlap as shown in FIG. 6. After the folding step S140, the plurality of jelly rolls 13 may be provided in the form of a folding structure 17 (see FIG. 7 ). Referring to FIG. 7, a schematic shape of a folding structure 17 obtained by folding a plurality of jelly rolls 13 according to an embodiment of the present invention can be confirmed. A cap plate 18 including a plurality of electrode terminals may be positioned on the folding structure 17.

In the square cell assembly step (S500), the folding structure 17 is accommodated in the inner storage space of the square case 19, and the cap plate and the remaining square cell components are assembled to seal the upper opening of the square case 19. This is the step (see Fig. 8). Here, the angular cell component may include a plurality of insulating parts, a plurality of leads, a gasket, and the like, and may further include components that are obvious to a person skilled in the art. Referring to FIG. 8, a schematic shape of a prismatic cell 20 that is entirely sealed using a prismatic case 19 according to an embodiment of the present invention can be confirmed.

Meanwhile, referring to FIG. 9, the prismatic cell 20 includes a plurality of electrode terminals 50 through the cap plate 18, and the plurality of electrode terminals 50 may include positive and negative terminals. In addition, each of the electrode terminals 50 may include a protruding head portion 60. The protruding head portion 60 has a shape extending outwardly from the center direction of the electrode terminal 50 by a set length from the inner center of the electrode terminal 50 and protruding from the inner center of the electrode terminal 50. For example, the protruding head portion 60 may have an I-shaped cross-section having a constant cross-sectional size with respect to the entire protruding portion. This protruding head part 60 facilitates the connection work of the bus bar, and is plastically deformed into a deformed head part 300 (see FIGS. 14 and 15) in a flat shape through spinning to connect the bus bar 100. Constrained to the state.

Busbar connection connection steps

This step is a busbar connection and connection step. When the assembly of the square cell is completed in the previous step, it refers to the step of connecting the busbar to the electrode terminal of the square cell and connecting it.

Referring to FIG. 3, a bus bar connection and connection step (S600) includes a bus bar connection step (S610), a spinning step of the protruding head of the electrode terminal (S620), and a bus bar connection fixing step (S630). And Figures 12 to 15 show a process diagram and a conceptual diagram of the bus bar connection connection step.

The bus bar connection step (S610) is a step of connecting the bus bar 100 to each of the plurality of electrode terminals 50 provided in the prismatic cell. The bus bar 100 has a through hole 110. The through hole 110 may be located at the end of the length of the bus bar 100, and the electrode terminal 50, more specifically, the protruding head portion 60 protruding outward from the electrode terminal 50 penetrates. Say the hole. It is preferable that the through hole 110 has a hole having the same or larger cross-section corresponding to the cross-sectional size and shape of the electrode terminal 50 and the protruding head 60. In other words, in order to facilitate the operation of inserting the electrode terminal 50 and the protruding head 60 into the through hole 110, the through hole 110 may be formed in a slightly larger size.

Meanwhile, a busbar annular groove 120 (refer to FIG. 14) that is deeply depressed set in the thickness of the bus bar 100 in the inner direction of the thickness of the bus bar 100 may be further provided on one surface of the bus bar 100. . Bus bar annular groove 120 (refer to FIG. 14) is plastically deformed when the protruding head 60 is pressed flat by a spinning tool 210 (refer to FIG. 12) after going through a spinning step (S620) to be described later. It provides an accommodation space in which 300 is closely adhered to. In other words, the busbar annular groove 120 (refer to FIG. 13) is in order to flatten the height of the central portion 310 of the deformable head portion 300 with the height of the upper surface of the bus bar 100 (see FIG. 14). It refers to a groove having a size in which the extension part 320 of the head part 300 is inserted and accommodated.

Accordingly, while securing a solid tight fixing structure between the bus bar 100 and the deformable head part 300, there is no remaining shape part protruding on the surface of the bus bar 100, providing a relatively smooth surface treatment and a finished shape. can do.

In addition, according to an embodiment of the present invention, as shown in FIG. 12, after passing through the spinning step S300, the deformable head part 300 may have a shape protruding from the upper surface of the bus bar by a predetermined height. In addition, although not shown separately, according to the embodiment of the present invention, the shape of the deformable head part 300 after passing through the spinning step (S300) is deformed according to the adjustment of the inclination angle (a) of the spinning tool 210 (refer to FIG. 13). Only the central portion of the head portion 300 may have a conical shape protruding upward. If it has a conical shape, it may have a shape in which the thickness of the extension part 320 gradually increases as it faces the center 310, so that the shape deformation of the busbar connection structure against external vibration and shock can be prevented. It has the advantage of increasing the necessary structural strength.

Spinning the protruding head part of the electrode terminal (S620) is a step of spinning the protruding head part 60 of the electrode terminal 50 connected to the through hole 110 of the bus bar 100. The shape protruding into the I-shaped cross section before the processing of the protruding head 60 through the spinning step S220 is deformed by being pressed flat as shown in FIG. 14 (or FIG. 15). The deformed protruding head portion 60 is referred to as a deformed head portion 300. The deformable head part 300 pressurizes the bus bar 100 to maintain the connected state.

The spinning operation may be performed by a dedicated spinning device 200 (see FIGS. 12 and 13 ). For example, referring to FIGS. 12 and 13, the spinning apparatus 200 includes a spinning tool 210 and a spinning body 220. The spinning tool 210 rotates at high speed along the setting direction R. The spinning tool 210 is in contact with the upper portion (and one side of the upper portion) of the protruding head portion 60 of the electrode terminal 50 while rotating at high speed, and may plastically deform the protruding shape of the protruding head portion 60 to be flat. As a result, the protruding head portion 60 may be deformed into a shape of a deformable head portion 300 that fixes the connection state by pressing the bus bar 100.

The spinning body 220 refers to a main body of the spinning device 200 that provides rotational force to the spinning tool 210. For example, the spinning body 220 may adjust the relative height of the spinning tool 210 with respect to the protruding head 60 of the electrode terminal 50, and adjust the center direction CL of the electrode terminal 50. As a reference, the spinning tool 210 may be tilted within a set angle range to have an inclined posture. Here, the inclination angle (a) may be determined within the range of 0 to 30 degrees as necessary, and the position where the tip portion 211 of the spinning tool 210 faces toward the protruding head portion 60 may be changed, so that the protrusion The head part 60 can be transformed into various shapes. For example, when the inclined posture of the spinning tool 210 is adjusted so that the tip 211 of the spinning tool 210 faces the circumferential edge of the protruding head 60, that is, the outer 61 of the protruding head , The deformable head part 300 may be processed into a shape in which the center protrudes high in a conical shape instead of the flat shape shown in FIGS. 14 and 15.

The bus bar 100 is pressed from the top by the deformable head part 300 in a state connected to the electrode terminal, and a necessary coupling force can be secured. Accordingly, it is possible to prevent deformation due to thermal shock by not using welding or the like, and it is possible to prevent the coupling force from being weakened due to vibration or external force when fastening using mechanical elements such as rivets.

The busbar connection fixing step (S630) refers to a step of forming a busbar connection structure by connecting the electrode terminal and the busbar with a necessary coupling force using the deformable head part 300 plastically deformed by spinning.

14 and 15, the final shape of a prismatic cell having a bus bar connection structure is shown. The through hole 110 of the bus bar 100 may have a size corresponding to the cross-section of the extension part 320 of the deformable head part 300. As a specific example, the upper end of the through hole 110 is formed slightly larger than the cross-sectional size of the expansion part 320, and the lower end of the through hole 130 has a shape before the spinning process of the deformable head part 300, that is, a protruding head part ( It may have a size corresponding to 60).

Spinning of current collector connection structure

Hereinafter, a description will be given of the spinning process step of the current collector connection structure according to an embodiment of the present invention.

According to an embodiment of the present invention, a main welding step of connecting the jelly roll and the current collector or a step of connecting the current collector and the cap plate by spinning may be performed after that.

In other words, the spinning process of the current collector and the cap plate may be performed after the main welding step.

Figure 2 is a flow chart showing the detailed steps of the spinning process of the current collector and the cap plate. Referring to FIG. 2, a current collector connection position alignment step (S310), a protrusion head spinning step (S320), and a current collector connection fixing step (S330) are included.

Current collector connection position alignment steps

This step is a current collector connection position alignment step (S310), by inserting the protrusion 400 protruding from the other surface of the cap plate 18 to a set length into the hole 510 of the current collector 500 to insert the current collector 500. It refers to the step of aligning the connection position.

Referring to FIG. 9, a protrusion 400 protrudes to a set length on the other surface of the cap plate 18, and a hole 510 through which the protrusion 400 passes is provided in the current collector 500.

The hole 510 may be formed to have the same or larger cross-sectional size corresponding to the cross-sectional sizes of the protrusion 400 and the protrusion head portion 410.

On the other hand, a current collector annular groove 520 (refer to FIG. 11) may be further provided on one surface of the current collector 500 and depressed by a set depth in the thickness inner direction of the current collector 500 around the hole 510. The current collector annular groove 520 (refer to FIG. 11) is formed by spinning the protruding head portion 410 by a spinning tool 610 (refer to FIG. 9) to have an extended cross-section 700. Provides an accommodation space in which at least some of them are closely adhered to.

In other words, the current collector annular groove 520 (refer to FIG. 11) is in advance to make the height of the central portion 710 of the extended cross-sectional portion 700 flat with the height of the upper surface of the current collector 500, in advance, the current collector 500 Can be provided in. The current collector annular groove 520 (refer to FIG. 11) has the advantage of increasing the adhesion between the current collector 500 and the extended cross-section 700 and enabling a smooth surface treatment so that there is no protruding shape on the surface of the current collector 500. . In addition, although not separately shown, the extended cross-sectional portion 700 may have a shape protruding a predetermined height above the current collector 500, and it is extended according to the adjustment of the inclination angle (a) of the spinning tool 610 (refer to FIG. 10). Only the central portion of the cross-sectional portion 700 may have a conical shape protruding upward. If the extended cross-sectional portion 700 has a conical shape, as the thickness of the extended portion 320 gradually increases toward the center 310, the extended cross-sectional portion is transformed in shape due to external vibration and shock. The effect of preventing the current collector connection structure from loosening or weakening of the connection state can be improved. And it can improve the necessary structural strength.

Spinning step of the protruding head

This step is a spinning step of the protrusion head (S320), which is a step of spinning the protrusion 400, more specifically, the protrusion head 410 through the hole 510 of the current collector 500. .

The protrusion head 410 has a protrusion length greater than the thickness of the current collector 500, and when the protrusion 400 is inserted into the hole, the protrusion head 410 protrudes above the current collector 500 by a set length. It can be provided in a structure.

The protruding head portion 410 may have a shape protruding in an I-shaped cross section before spinning. After the spinning process is performed through this step, the protruding head portion 410 may be plastically deformed into an expanded cross-sectional portion 700 (see FIG. 11) whose cross-section is extended in the width direction.

The extended cross-sectional portion 700 (see FIG. 11) may firmly fix the connection of the current collector 500 by pressing the current collector 500 downward from the top of the current collector 500.

The spinning operation in this step S400 may be performed by a dedicated spinning device 600. For example, the spinning apparatus 600 may include a spinning tool 610 and a spinning body 620 (see FIGS. 9 and 10 ).

The spinning tool 610 rotates at a high speed along the setting direction (R), and is in contact with the upper (and upper one side) of the protruding head part 410, and extends the shape of the protruding head part 410 to the expanded cross-sectional part 700, FIG. 11 Can be plastically deformed.

The spinning body 620 may provide rotational force to the spinning tool 610. In addition, the spinning body 620 may adjust the relative height of the spinning tool 610 with respect to the protruding head portion 410, and the spinning tool 610 based on the center direction CL of the protruding head portion 410 The tilting drive can be performed within a set angle range to have this inclined posture.

Here, the inclination angle (a) may be determined within the range of 0 to 30 degrees as necessary, and the position where the tip portion 611 of the spinning tool 610 faces toward the protrusion head portion 410 may be changed. The head part 410 can be transformed into various shapes.

For example, when the posture of the spinning tool 610 is adjusted to be inclined so that the tip portion 611 of the spinning tool 610 faces the circumferential edge portion of the protrusion head portion 410, that is, the outside 411 of the protrusion head portion, The expanded cross-sectional portion 700 (see FIG. 11) may be processed into a shape in which the center protrudes high in a conical shape rather than a flat shape as shown.

In this way, the extended cross-sectional portion 700 (see FIG. 11) presses and presses the current collector 500 to strengthen the connection portion, and also has the advantage of preventing the separation of the current collector 500 according to its shape characteristics. have. Therefore, it is not necessary to use laser welding or the like, so that deformation due to thermal shock can be prevented, and problems that are vulnerable to vibration and impact when fastening using mechanical elements such as rivets can be prevented. Therefore, when applied to a power device such as a vehicle, the effect can be further improved.

Current collector connection fixed stage

This step is a current collector connection and fixing step (S330), and the current collector 500 is firmly connected to the aligned position using the expanded cross-section 700 of the protruding head 410 plastically deformed by spinning. It refers to the step of fixing it.

Referring to FIG. 11, a coupling relationship between the shape of the extended cross-sectional portion 700 and the current collector 500 can be confirmed. As shown, the extended cross-sectional portion 700 is the head portion of the protrusion passing through the hole 510 of the current collector 500 is deformed by spinning, and the contact and pressing action of the extended cross-sectional portion 700 As a result, the current collector 500 is firmly bonded, and a necessary bonding force can be secured.

At this time, around the hole 510 of the current collector 500, a current collector annular groove 520 is formed. Through the annular groove 520, the lower portion of the expansion part 720 is partially inserted and adhered to each other. Can be fixed in contact with the area. As a result, the current collector annular groove 520 may increase the contact area between the current collector 500 and the extended cross-section 700 to further improve a coupling force required to maintain a solid connection state. In addition, it is possible to flatten the height of the central portion 710 of the extended sectional portion 700 with the height of the upper surface of the current collector 500, so that the extended sectional portion 700 does not protrude above the surface of the current collector 500. Therefore, there is an advantage that a smooth surface treatment is possible.

On the other hand, according to an embodiment of the present invention described above, in applying the spinning method when connecting the current collector to which the jelly roll is connected by main welding to the cap plate, the multi-tap method in which the electrode uncoated part is drawn out and connected has been described as an example. However, although not shown separately, the present invention is not limited to the above multi-tap method, and can also be applied to the case of a side tap method in which the uncoated electrode portion is drawn out to both sides during rectangular winding and main welding is performed with the current collector. It can be appropriately changed and applied to various methods of tolerance that are self-evident.

As described above, according to the configuration and operation of the present invention, by improving the structure of connecting the current collector to the prismatic cell, it is possible to increase the fixing strength of the current collector of the prismatic cell, thereby having a structure that is strong against vibration and external shock.

In addition, when the spinning process is used, there is an advantage that there is no restriction due to the heterogeneous material between the current collector material and the joint portion thereof, and problems such as thermal shock, which are concerned when using laser welding, etc., can be prevented in advance.

As described above with reference to the drawings illustrated for the present invention, the present invention is not limited by the embodiments and drawings disclosed in the present specification, and various by a person skilled in the art within the scope of the technical idea of the present invention. It is obvious that transformations can be made. In addition, even if not explicitly described and described the effect of the configuration of the present invention while describing some embodiments of the present invention, it is natural that the predictable effect by the configuration should also be recognized.

S100: stack step
S200: pre-welding step
S300: main welding step
S400: folding step
S500: square cell assembly steps
S600: Busbar connection connection step
11: stack structure
13: jelly roll
15: terminal and cap
17: folding structure
18: cap plate
19: case
20: square cell
50: electrode terminal
60: protruding head
61: outside of the protruding head
100: bus bar
110: through hole
120: annular groove
130: lower through hole
200: spinning device
210: spinning tool
211: tool tip
220: spinning body
330: deformation head portion
310: central part
320: extension
400: protrusion
410: protruding head
411: outside of the protruding head
500: current collector
510: hall
520: annular groove
530: lower part of the hole
600: spinning device
610: spinning tool
611: tool tip
620: spinning body
630: deformation head portion
700: extended section
710: central part
720: extension

Claims (13)

(a) preparing a jelly roll; (b) a pre-welding step of connecting the jelly roll and the electrode uncoated portion; (c) a main-welding step of connecting the jelly roll on which the pre-welding has been completed and the current collector; And (d) assembling a cap plate having a plurality of electrode terminals to accommodate the jelly roll on which the main welding has been completed in a prismatic case and seal the prismatic case.
After the step (c), a step of connecting the current collector and the cap plate through a spinning process, wherein (c-1) a protrusion protruding from the cap plate to a set length is inserted into the hole of the current collector. Aligning the connection positions of the current collectors, (c-2) plastically deforming the protruding head portion protruding through the hole of the current collector by spinning, and (c-3) plasticizing it by the spinning process. Further comprising the step of connecting the current collector to the aligned position using the extended cross-section of the deformed protrusion head,
In the step (c-1), the hole has a cross-sectional size equal to or greater than that corresponding to the cross-sectional size of the protrusion and the protrusion head, and the thickness of the current collector surrounds the hole on one surface of the current collector. The current collector annular groove is further provided with a set depth recessed in the inner direction, and the current collector annular groove has an accommodation space in which at least a part of the extended end face is in close contact with each other when the protruding head portion is spin-processed to have the extended end face. And
By flattening the height of the central portion of the expanded cross-section with the height of the upper surface of the current collector, increasing the adhesion between the current collector and the expanded cross-section, forming a smooth surface so that there is no protruding shape on the surface of the current collector. ,
In the step (c-2), the protrusion head portion has a protruding length greater than a thickness of the current collector, and when the protrusion is inserted into the hole, it protrudes to an upper portion of the current collector by a set length,
In the step (c-2), the spinning operation is performed by a spinning device including a spinning tool that rotates at high speed and a spinning body that provides rotational force to the spinning tool, with the spinning tool based on the protruding head. The height of the spinning tool is tilted within a set angle range so that the spinning tool has an inclined posture based on the center direction of the protruding head, so that the position where the tip of the spinning tool faces toward the protruding head can be changed. Characterized by
A method of manufacturing a prismatic cell having a current collector connection structure.
delete delete delete delete The method of claim 1,
In step (c-3),
The expanded cross-sectional portion of the protrusion head part plastically deformed by the spinning process has a shape for restraining the connection position by pressing the current collector connected to the protrusion with a predetermined force.
A method of manufacturing a prismatic cell having a current collector connection structure.
The method of claim 1,
In the step (a), the jelly roll is a stack type jelly roll in the form of a stack structure in which the electrode assembly is stacked up and down, or a rectangular wound type jelly roll.
A method of manufacturing a prismatic cell having a current collector connection structure.
The method of claim 1,
After the step (c), preparing a folding structure by folding the plurality of jelly rolls connected to each other;
Prismatic cell manufacturing method having a current collector connection structure further comprising a.
The method of claim 1,
After step (d),
(e) connecting a bus bar to the plurality of electrode terminals of the assembled prismatic cell by spinning;
Prismatic cell manufacturing method having a current collector connection structure further comprising a.
The method of claim 9,
The step (e),
(e-1) connecting the bus bar to each of the plurality of electrode terminals;
(e-2) spinning the protruding heads of each of the plurality of electrode terminals protruding from the top of the bus bar to transform the protruding head into a deformable head that can pressurize the bus bar; And
(e-3) a bus bar connection step of connecting each of the plurality of electrode terminals and the bus bar with a necessary coupling force using the deformable head portion;
Prismatic cell manufacturing method having a current collector connection structure comprising a.
The method of claim 10,
In step (e-1),
The bus bar, characterized in that having a through hole through which the electrode terminal passes through at least one end and is interconnected.
A method of manufacturing a prismatic cell having a current collector connection structure.
The method of claim 11,
In step (e-2),
The protruding head portion has a shape extending outwardly from the center direction of the electrode terminal by a set length from the inner center of the electrode terminal.
A method of manufacturing a prismatic cell having a current collector connection structure.
A prismatic cell having a current collector connection structure manufactured using the method of manufacturing a prismatic cell having a current collector connection structure according to any one of claims 1, 6 to 12,
The prismatic cell includes a bus bar connected to each of the plurality of electrode terminals provided on one surface of the cap plate, and a current collector connected using the plurality of protrusions provided on the other surface of the cap plate,
A bus bar connection that connects each of the plurality of electrode terminals and the bus bar using the plurality of deformable head portions by spinning the protruding head portion protruding from each of the plurality of electrode terminals and plastically deforming into the plurality of deformable head portions Having a structure, and plastically deformed by spinning a protrusion head protruding to each of the plurality of protrusions, and having a current collector connection structure connecting each of the plurality of protrusions and the current collector using the expanded end portion of the protruding head part.
Prismatic cell with current collector connection structure.

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