Apparatus for manufacturing a secondary battery, method for manufacturing a secondary battery using the same, and secondary battery manufactured using the same
Patent Information
- Application Number
- ES2023843441T
- Authority / Receiving Office
- ES · ES
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2023-07-21
- Filing Date
- 2023-07-21
- Publication Date
- 2026-08-31
- Estimated Expiration
- 2043-07-21
Smart Images
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Abstract
Description
Apparatus for manufacturing a secondary battery, method for manufacturing a secondary battery using the same, and secondary battery manufactured using the same TECHNICAL FIELD This application claims the benefit of priority of Korean patent applications No. 10-2022-0091361, filed on July 22, 2022, and 10-2023-0095316, filed on July 21, 2023. The present invention relates to an apparatus for manufacturing a secondary battery, a method for manufacturing a secondary battery using the same, and a secondary battery manufactured using the same, and more particularly, to an apparatus for manufacturing a secondary battery that cuts a tab from the electrode of the secondary battery, a method for manufacturing a secondary battery using the same, and a secondary battery manufactured using the same. BACKGROUND OF THE ART Batteries (cells) that generate electrical energy through a physical or chemical reaction to supply the generated electrical energy to the outside are used when AC power that must be supplied to the building is not obtained, or DC power is required according to living environments surrounded by various electrical and electronic devices. Among such batteries, primary and secondary batteries are commonly used. These are chemical batteries that utilize a chemical reaction. A primary battery is simply called a battery and is a consumable battery. Secondary batteries are rechargeable batteries manufactured using a material in a redox process between an electric current and a substance that can be repeated multiple times. When the reduction reaction occurs in the material via the electric current, energy is stored; when the oxidation reaction occurs, energy is released. This charging and discharging process is repeated to generate electricity. This secondary battery typically has a structure that includes an electrode array, in which the electrodes and separators are stacked alternately, and an electrode flange attached to each electrode. Here, the electrode flange is processed to be cut by a cutting element, etc., and after processing, the electrode flange is attached to the electrode by welding or similar means. The electrode assembly described above undergoes expansion due to an activation process, etc. A problem arises here: the burr formed during the cutting process of the electrode flange damages the electrode, resulting in holes or cracks. The relevant prior art is known from documents WO 2022 / 015022 A1 and KR 20220035741 A. As a result, it is necessary to develop a technology to solve the aforementioned problems. DISCLOSURE OF THE INVENTION TECHNICAL PROBLEM The present invention has been invented to solve the aforementioned problem, and an object of the present invention is to provide an apparatus for manufacturing a secondary battery, which manufactures an electrode tab capable of preventing an electrode from being damaged, a method for manufacturing a secondary battery using the same, and a secondary battery manufactured using the same. TECHNICAL SOLUTION The present invention provides an apparatus for manufacturing a secondary battery, comprising: an electrode assembly in which the electrodes and separators are stacked alternately; and an electrode flange attached to each of the electrodes, the apparatus including: a cutting element disposed on one side of the electrode flange for moving toward the electrode flange in order to cut a portion to be cut from the electrode flange; and a joining die disposed to cross the cutting element on the other side of the electrode flange, wherein the cutting element includes: a pressure surface configured to press the electrode flange; and an inclined surface provided in a position corresponding to the portion to be cut and extending at an angle away from the electrode flange from one end of the pressure surface. One end of the inclined surface may be shaped to be concave inwards. The inclined surface may extend to be inclined at an angle of 30 degrees to 70 degrees. One end of the joining die can be arranged in a position corresponding to the portion to be cut from the electrode flange and have a shape that protrudes convexly outwards. The apparatus may further include a transfer part coupled to the electrode flange below the electrode flange, where the joining die may be provided above the electrode flange, and the cutting element may be provided below the electrode flange to move upwards. The secondary battery may include a cylindrical secondary battery. The present invention provides a method for manufacturing a secondary battery, comprising: an electrode assembly in which the electrodes and separators are stacked alternately; and an electrode flange attached to each of the electrodes, the method including: an electrode flange cutting process to cut a portion to be cut from the electrode flange; and an electrode flange joining process to the electrode, wherein, in the electrode flange cutting process, a cutting element moves toward the electrode flange to cut the portion to be cut from the electrode flange, and the cutting element includes: a pressure surface that presses the electrode flange; and an inclined surface provided in a position corresponding to the portion to be cut and extending inclinedly away from the electrode flange from one end of the pressure surface. In the process of cutting the electrode tab, the cutting element arranged under the electrode tab can move upwards with respect to the electrode tab to cut it, and in the process of joining the electrode tab, the electrode tab can be joined to an upper side of the electrode. A secondary battery according to the present invention includes: an electrode assembly in which the electrodes and separators are stacked alternately; an electrode flange attached to each of the electrodes; and a battery housing in which the electrode assembly and the electrode flange are housed, wherein a burr generated on an edge of the electrode flange due to cutting may protrude in a direction facing the battery housing. A corner of the electrode tab can be provided in a curved shape that has a radius of curvature in a plane. The corner of the electrode flange that has the radius of curvature may be positioned over the electrode. The radius of curvature of the corner of the electrode flange may be greater than 1 / 2 the width of the electrode flange. The electrode assembly may be wound in a state in which the electrodes and separators are stacked sequentially, and the battery casing may be cylindrical in shape and configured to accommodate the electrode assembly. ADVANTAGEOUS EFFECTS The present invention can have the effect of reducing the protruding angle of the burr on the electrode flange to minimize electrode damage due to the electrode flange by cutting the electrode flange using the cutting element having the inclined surface that extends to tilt away from the electrode flange from the pressure surface that presses the electrode flange. Furthermore, the present invention can have the effect of forming the corner of the electrode flange in a rounded shape to minimize damage to the electrode flange due to cutting the electrode flange using the cutting element whose inclined surface end has a shape that is recessed inwards in a concave manner. Furthermore, the present invention may include a transfer portion configured to transfer the electrode to the underside of the electrode flange. Thus, the cutting element may be positioned beneath the electrode flange to cut the electrode flange using an upward-moving cutting element such that the burr protrudes from the electrode flange in the direction opposite the electrode, i.e., the direction facing the battery housing, to minimize electrode damage caused by the electrode flange. BRIEF DESCRIPTION OF THE DRAWINGS FIG.1 is a perspective view illustrating an apparatus for manufacturing a secondary battery according to embodiment 1 of the present invention. FIG. 2 is a cross-sectional side view illustrating a cut element of the apparatus for making the secondary battery of FIG. 1 when viewed in an AA direction. FIG.3a is a side cross-sectional view illustrating an electrode flange manufactured by the apparatus for making a secondary battery of FIG.1. FIG.3b is a side cross-sectional view illustrating another electrode flange manufactured by the apparatus for making a secondary battery of FIG.1. FIG. 4 is a detailed plan view illustrating a cutting element in the apparatus for manufacturing a secondary battery of FIG. 1. FIG. 5 is a conceptual view illustrating a state in which the electrode tab manufactured by the secondary battery making apparatus of FIG. 1 is attached to an electrode. Figure 6a is a conceptual view illustrating a state in which the electrode flange manufactured by the secondary battery manufacturing apparatus of Figure 1 is arranged between the electrode and a battery casing. Figure 6b is a conceptual view illustrating a state in which an electrode flange manufactured by a secondary battery manufacturing apparatus according to the related technique is arranged between an electrode and a battery casing. FIG. 7 is a flowchart illustrating an order in a method for manufacturing a secondary battery according to embodiment 2 of the present invention. METHOD FOR CARRYING OUT THE INVENTION The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings so that those of ordinary skill in the art may readily carry out the present invention. However, the present invention can be implemented in several different ways and is not limited or restricted by the following examples. To clearly explain the present invention, detailed descriptions of parts irrelevant to the description or of related known technologies that might unnecessarily obscure the core of the present invention have been omitted. In this specification, reference symbols are added to the components in each drawing. In this case, the same or similar reference numbers are assigned to the same or similar elements throughout the specification. Furthermore, the terms or words used in this specification and in the claims should not be interpreted restrictively as having ordinary or dictionary-based meanings, but should be interpreted as meanings and concepts that fit the scope of the present invention on the basis of the principle that an inventor can adequately define the concept of a term to best describe and explain his invention. Device for manufacturing a secondary battery The present invention provides an apparatus for manufacturing a secondary battery 100, comprising: an electrode assembly in which the electrodes 20 and separators (not shown) are stacked alternately; and an electrode tab 10 attached to the electrodes 20. The apparatus 100 includes: a cutting element 120 disposed on one side of the electrode tab 10 for movement toward the electrode tab 10 in order to cut a portion of the electrode tab 10 to be cut; and a joining die provided for crossing the cutting element 120 on the other side of the electrode tab 10. The cutting element 120 includes: a pressure surface 121 that presses the electrode tab 10; and an inclined surface 122 disposed in a position corresponding to the portion to be cut and extending at an angle away from the electrode tab from one end of the pressure surface 121. Here, the electrode assembly can be configured so that the electrodes 20 and the separators (not shown) are stacked alternately and can have various structures. Specifically, the electrode assembly can have a structure in which positive electrode collector / positive electrode active material layer / separator / negative electrode active material layer / negative electrode collector are stacked sequentially such that the positive electrode active material layer disposed on one separator surface faces the negative electrode active material layer disposed on the other separator surface. The electrode assembly can be wound in a state where the electrodes 20 and separators are stacked sequentially and then accommodated in a battery housing 30, which will be described later. At least one or more electrode 10 tabs can be attached to each of the electrodes 20. Here, the electrode 10 tab can be connected to an electrode terminal (not shown) that protrudes from the battery housing 30, and thus the electrode assembly within the battery housing 30 can be electrically connected to an external electrical device or an external secondary battery. The electrode 10 tab can be attached to the electrode 20 by laser welding, ultrasonic welding, resistance welding, etc. Furthermore, the flange of electrode 10 may be joined to electrode 20 by welding, and thus at least one or more weld areas a may be provided on the flange of electrode 10 and electrode 20. Here, weld area a may be understood as an area in which deformation occurs on the flange of electrode 10 or electrode 20 during a pressing and / or heating process of the flange of electrode 10 and electrode 20 during welding. Before joining the electrode 10 tab to the electrode 20, as illustrated in FIG. 1, the electrode 10 tab can be cut by the cutting element 120 and then processed to have a size and shape desired by a user. Specifically, the cutting element 120 can be arranged to one side of the electrode flange 10 to move towards the electrode flange 10 and can cut a portion to be cut from the electrode flange 10. Here, the portion to be cut can be a portion of the electrode flange 10 that is cut and processed by the cutting element 120 and can be understood as a portion corresponding to the cut portion of the electrode flange 10 on which a cutting process is performed. In more detail, the cutting element 120 can be arranged on one side of the electrode tab 10 to move towards the electrode tab 10 in order to process the electrode tab 10. For example, the cutting element 120 can be arranged on the top or bottom side of the electrode tab 10 to move towards the electrode tab 10. The cutting element 120 can have several structures. For example, as shown in FIG. 2, the cutting element 120 may include: a pressure surface 121 that presses the electrode flange 10; and an inclined surface 122 that is provided in a position corresponding to the portion to be cut and extends at an angle away from the electrode flange 10 from one end of the pressure surface 121. Here, FIG. 2 is a side cross-sectional view of the cutting element 120, but note that the electrode flange 10 is further illustrated on the cutting element 120 to help understand the position and direction of movement of the cutting element 120.Here, a dotted line expressed on the cutting element 120 can be expressed to distinguish areas of the pressure surface 121 and the inclined surface 122 in a cross section of the cutting element 120, but note that this does not mean that the pressure surface 121 and the inclined surface 122 are separated from each other. Here, the pressure surface 121 can be a surface provided in a position opposite the electrode flange 10 on the cutting element 120 to press against a surface of the electrode flange 10 and can have various structures. For example, as illustrated in FIG. 2, the pressure surface 121 can have a structure that extends in one direction (parallel to the X direction in FIG. 2) parallel to a surface of the electrode flange 10 to uniformly press against a surface of the electrode flange 10. The inclined surface 122 can be arranged in a position corresponding to the portion to be cut and can be configured to extend at an angle away from the electrode flange 10 from the end of the pressure surface 121 and can also have various structures. For example, as shown in FIG. 2, the inclined surface 122 can be provided to extend at an angle so that the distance between the end of the pressure surface 121 and the electrode flange 10 (a Z direction in FIG. 2) increases. This inclined surface 122 can be arranged in a position corresponding to the portion to be cut, and thus, when the flange of the electrode 10 is cut, the formation of a burr generated by the cutting is generated on the cut portion of the flange of the electrode 10 and the protruding height of the burr can be minimized. The inclined surface 122 can be arranged to be inclined at various angles of inclination from the pressure surface 121. However, since the protruding height of the burr generated on the portion to be cut from the electrode flange 10 increases in proportion to the angle of inclination of the inclined surface 122, it is preferable that the angle of inclination be less than a certain angle. In more detail, FIGS. 3a and 3b illustrate electrode tabs 10 where the inclined surface 122 is cut by the cutting element 120 at different angles of inclination. That is, the electrode tab 10 in FIG. Figure 3a may be a flange of electrode 10 provided by cutting the flange of electrode 10 using the cutting element 120, of which the angle of inclination of the inclined surface 122 is 30 degrees, and the flange of electrode 10 in Figure 3b may be a flange of electrode 10 provided by cutting the flange of electrode 10 using the cutting element 120, of which the angle of inclination of the inclined surface 122 is 50 degrees. Referring to Figures 3a to 3b, it is observed that the protruding height of the burr of the flange of electrode 10 in Figure 3b is greater than that of the burr of the flange of electrode 10 in Figure 3a. Thus, it is observed that the angle of inclination must be less than a certain angle. However, even considering this structure, if the tilt angle is too small, a problem may occur where the processing of the inclined surface 122 is difficult when manufacturing the cutting element 120, and therefore the tilt angle may not be defined at a predetermined angle or more. Therefore, it may be desirable for the inclined surface 122 to extend at an angle of 30 degrees to 70 degrees from the pressure surface 121. This is because, as described above, when the angle of inclination is less than 30 degrees, machining the inclined surface 122 can be difficult when manufacturing the cutting element 120, and when the angle of inclination exceeds 70 degrees, the protruding burr height may be too large and negatively affect the quality of the secondary battery. The inclined surface 122 can have several shapes. Here, one end of the inclined surface 122 may have a shape that is recessed concavely inwards, as illustrated in FIG. 4. In this case, as shown in FIG. 5, a corner of the electrode flange 10 cut by the cutting element 120 may not define a right angle, but may be provided in a curved shape with a radius of curvature in a plane. Thus, after the tab of electrode 10 is attached to electrode 20, even if the electrode assembly expands due to an activation process, etc., the stress concentration at the corner of the tab of electrode 10 can be relieved to prevent damage to electrode 20. The electrode flange 10 cut by the cutting element 120 can be fixedly supported by the joining die 110. Here, the joining die 110 can be configured to be arranged so that it crosses the cutting element 120 on the other side of the electrode flange 10 and can have various configurations. Specifically, the joining die 110 can be arranged so that it does not interfere with the cutting element 120 on the other side of the electrode flange 10. Furthermore, the joining die 110 can be understood as a configuration that fixes and supports a partial area of the electrode flange 10 so that, when the electrode flange 10 is pressed by the cutting element 120, the electrode flange 10 is easily cut along the portion to be cut. Here, when the cutting element 120 is arranged on one side of the electrode flange 10, the joining die 110 can be arranged on the other side of the electrode flange 10. In this case, the joining die 110 can be arranged on either the top or bottom side of the electrode flange 10. The 110 joining die can have several shapes. For example, as described above, when the end of the inclined surface 122 of the cutting element 120 has a shape that is recessed concavely inwards, one end of the joining die 110 can be arranged in a position corresponding to the portion to be cut from the electrode flange 10 and can have a shape that protrudes convexly outwards. Here, the convexly protruding shape of one end of the joining die 110 can be provided to correspond to the concavely recessed shape of the end of the inclined surface 122 of the cutting element 120. In this case, there is an advantage in that a fracture surface generated when cutting the electrode flange 10 is provided smoothly by minimizing a gap between the joining die 110 and the cutting element 120. The apparatus 100 for manufacturing a secondary battery according to the present invention may further include a transfer portion (not shown) that transfers the electrode 20, coupled to the electrode flange 10, to the underside of the electrode flange 10. The transfer portion (not shown) may have any configuration, provided that it is capable of transferring the electrode 20, and may be configured, for example, as a conveyor belt. Furthermore, the tab of electrode 10, cut by the cutting element 120, can be moved to the electrode 20, which is transferred by the transfer part (not shown). In other words, the tab of electrode 10 can be cut by the cutting element 120 and then moved to the upper surface of electrode 20, which is transferred in the transfer part (not shown). When the transfer part is provided as described above, the joining die 110 described above can be provided above the electrode flange 10, and the cutting element 120 can preferably be provided below the electrode flange 10 to move upwards. This is because, as the transfer part transfers electrode 20 to the lower side of the electrode 10 tab, as illustrated in FIG. 5, the electrode 10 tab is attached to the upper side of electrode 20. Here, when the cutting element 120 moves upward from the lower side of the electrode 10 tab to cut the electrode 10 tab, the burr generated on the edge of the electrode 10 tab can be directed upwards. Furthermore, compared to a case where the electrode 20 is welded to the upper surface of the electrode 10 flange in a state where the cut electrode 10 flange is arranged, when the electrode flange is welded to the upper surface of the electrode 20 in the state where the electrode 20 is arranged, it can be more efficient, and therefore, it is preferable that the cutting element 120 be provided below the electrode 10 flange so that it moves upwards so that the electrode 10 flange is attached to the upper side of the electrode 20. Specifically, electrode 20 can be fabricated by applying an active material to the electrode plate made of a metal. Due to the characteristics of electrode 20, its size may be larger than that of the cut electrode tab 10, and its weight may be greater than that of the cut electrode tab 10. Therefore, it is desirable to attach the electrode tab 10 to the upper surface of electrode 20 in its current state. Furthermore, due to the characteristics of the welding process, the weld can be performed by defining the weld area on the upper surface of the electrode 10 flange when the electrode 10 flange is positioned on the upper surface of electrode 20. Therefore, it is more efficient to perform the weld by pressing the lower surface of the electrode 10 flange when it is positioned on the lower surface of electrode 20. Similarly, it is preferable for the cutting element 120 to be positioned under the electrode 10 flange and moved upwards so that the electrode 10 flange is joined to the upper side of electrode 20. In this case, the burr generated due to the cut in the flange of electrode 10 can protrude in the opposite direction of electrode 20 to prevent electrode 20 from being damaged by the burr. Specifically, the secondary battery manufactured by apparatus 100 for manufacturing a secondary battery can include a cylindrical secondary battery. Due to the manufacturing characteristics of the cylindrical secondary battery, electrode 20 can be rolled in a state where the flange of electrode 10 is welded to it. That is, electrode 20 can be in the form of a jelly roll and then accommodated in the body of the cylindrical battery, with the flange of electrode 10 facing an internal surface of the battery body. In the state where electrode 20 is in the form of a jelly roll, i.e., the electrode assembly is housed in the battery body, the activation process can be performed, and then a top cap can be placed on the upper side of the battery body to manufacture the cylindrical secondary battery. Electrode 20 may include a negative electrode connected to the inner surface of the battery body, which has a negative polarity, and a positive electrode connected to the top cap, which has a positive polarity. In this case, electrode 20, to which the tab of electrode 10 is welded, may be the negative electrode. That is, in the state in which the flange of electrode 10 is welded and coupled to the negative electrode so that the burr of the flange of electrode 10 protrudes in the opposite direction of the negative electrode, the positive electrode and the negative electrode can be rolled so that the burr of the flange of electrode 10 faces towards the inner surface of the battery body, and then, the burr of the flange of electrode 10 can be coupled to the inner surface of the battery body. As a result, when the cutting element 120, located on the underside of the electrode 10 flange, moves upward to generate the burr of the electrode 10 flange, the cut electrode 10 flange can be welded and attached to the upper surface of the electrode 20 located in the transfer section. Electrode 20, i.e., the negative electrode, can then be wound to fit into the battery body so that the burr of the electrode 10 flange faces outward. This allows the burr of the electrode 10 flange to be attached to the inner surface of the battery body instead of electrode 20. Thus, electrode 20 is not damaged by the burr of the electrode 10 flange. This can be explained in more detail with reference to FIGS.6a to 6b. Specifically, FIG. 6a is a view illustrating a state in which the flange of electrode 10 is disposed on the upper side of electrode 20, and the burr generated on the edge of the flange of electrode 10 protrudes upwards so that the burr is disposed in the direction facing the battery housing 30, which is the opposite direction of electrode 20. In this case, since the outward direction of the burr is opposite to electrode 20, electrode 20 may not be damaged by the burr even if electrode 20 expands. Furthermore, FIG. 6b is a view illustrating a state in which the flange of electrode 10 is arranged on the upper side of electrode 20, and the burr generated on the edge of the flange of electrode 10 protrudes downwards so that the burr is arranged in the direction facing electrode 20. In this case, since the outward direction of the burr faces electrode 20, even if electrode 20 expands, the problem may occur in which the burr damages electrode 20, deteriorating the quality of the secondary battery. That is, in the present invention, when the flange of electrode 10 is attached to the upper side of electrode 20 as described above, the cutting element 120 can be arranged below the flange of electrode 10, and the cutting element 120 can be moved upwards to cut the flange of electrode 10 so that the burr protrudes in the opposite direction of electrode 20, thereby preventing damage to electrode 20. When the flange of electrode 10 is attached to the lower side of electrode 20 as described above, the cutting element 120 can be arranged above the flange of electrode 10, and the cutting element 120 can be moved downwards to cut the flange of electrode 10 so that the burr protrudes in the opposite direction of electrode 20, thus preventing electrode 20 from being damaged. Method for manufacturing a secondary battery As illustrated in FIG.7, the present invention provides a method for manufacturing a secondary battery, which includes: an electrode assembly in which the electrodes 20 and separators are stacked alternately; and an electrode tab 10 attached to each of the electrodes 20, the method includes: an electrode tab cutting process (S10) of cutting a portion to be cut from the electrode tab 10; and an electrode tab joining process (S20) of joining the electrode tab 10 to the electrode 20.In the process of cutting the electrode tab (S10), a cutting element 120 moves toward the electrode tab 10 to cut the portion to be cut from the electrode tab 10, and the cutting element 120 includes: a pressure surface 121 that presses the electrode tab 10; and an inclined surface provided in a position corresponding to the portion to be cut and extending at an angle away from the electrode tab 10 from one end of the pressure surface. Here, the process of cutting the electrode tab (S10) can be a process of cutting the portion to be cut from the electrode tab 10 and can be done in various ways. Specifically, the process of cutting the electrode tab (S10) can be performed by moving the cutting element 120 towards the electrode tab 10 to cut the portion to be cut from the electrode tab 10. In more detail, the process of cutting the electrode tab (S10) can be performed by moving the cutting element 120 towards the upper or lower side of the electrode tab 10 depending on the positions of the cutting element 120 and the electrode tab 10 to cut the electrode tab 10. Here, in the process of cutting the electrode flange (S10), the positions of the cutting element 120 and the electrode flange 10 and the direction of movement of the cutting element 120 may vary in consideration of the position in which the electrode flange 10 is attached to the electrode 20 in the process of joining the electrode flange (S20) which will be described later and the direction of burr formation. For example, when the electrode tab 10 is attached to the top side of the electrode 20 in the electrode tab joining process (S20) described later, the electrode tab cutting process (S10) can be performed while the cutting element 120 disposed under the electrode tab 10 moves upwards relative to the electrode tab 10 to cut the electrode tab 10. Here, the cutting element 120 may include: a pressure surface 121 that presses the electrode flange 10; and an inclined surface 122 that is provided in a position corresponding to the portion to be cut and extends at an angle away from the electrode flange 10 from one end of the pressure surface 121. Here, the more specific contents of the cutting element 120 will be replaced with the contents described above. Furthermore, the process of joining the S20 electrode tab can be a process of joining the electrode 10 tab to the electrode 20 and can be done in various ways. Specifically, the process of joining the S20 electrode flange can be accomplished by attaching the flange of electrode 10 to electrode 20 using laser welding, ultrasonic welding, resistance welding, etc. Here, the flange of electrode 10 can be joined to either the top or bottom side of electrode 20. Secondary battery The present invention may provide a secondary battery comprising: an electrode assembly wherein the electrodes 20 and separators are stacked alternately; an electrode tab 10 attached to each of the electrodes 20; and a battery housing 30 in which the electrode assembly and the electrode tab 10 are housed, and in which a burr generated due to cutting on an edge of the electrode tab 10 protrudes in a direction facing the battery housing 30. Here, the specific details regarding electrode 20 and the tab of electrode 10 will be replaced with the details described above. Furthermore, the secondary battery can be of various types, for example, a cylindrical secondary battery. Furthermore, the battery casing 30 can be configured to accommodate the electrode assembly and electrode tab 10 and can have various structures. For example, the battery casing 30 can have various shapes and materials, such as a cylindrical shape, a prismatic shape, and a pouch shape. The secondary battery can be a secondary battery manufactured by the apparatus for manufacturing a secondary battery 100 described above and the method for manufacturing a secondary battery. Here, the electrode tab 10 can be cut by the joining die 110 and the cutting element 120 described above. Here, the secondary battery can have a structure in which the burr generated by the cutting process on the edge of the electrode 10 tab is arranged in the opposite direction of the electrode 20, i.e., in the direction facing the battery casing 30, and thus, damage to electrode 20 due to the burr from the electrode 10 tab can be prevented. In the present invention, the corner of the electrode flange 10 can be provided in a curved shape with a radius of curvature in the plane. That is, the corner of the electrode flange 10 can have a rounded shape. As a result, the stress concentration at the corner of the electrode flange 10 can be relieved. In particular, the corner of the tab of electrode 10 that has the radius of curvature can be arranged over electrode 20, and thus the problem where the corner of the tab of electrode 10 tears electrode 20 or damages electrode 20 can be prevented to improve the stability of the secondary battery. The radius of curvature of the corner of the electrode 10 flange can be provided in various ways. However, to alleviate stress concentration at the corner of the electrode 10 flange, it may be preferable for the radius of curvature of the corner of the electrode 10 flange to be greater than 1 / 2 of the width W of the electrode 10 flange. For example, when the width W of the electrode 10 flange is 40 mm, the radius of curvature of the corner of the electrode 10 flange may be greater than 20 mm. Although examples of applications of the present invention have been described with reference to specific embodiments, it will be evident to those skilled in the art that various changes and modifications can be made without departing from the scope of the invention as defined in the following claims. [Description of the symbols] 10: Electrode tab 20: Electrode 30: Battery casing 100: Device for manufacturing a secondary battery 110: Joining die 120: Cutting element 121: Pressure surface 122: Inclined surface S10: Electrode tab cutting process S20; Electrode tab bonding process : Inclined angle W: Electrode tab width a: Welding area
Claims
1. An apparatus for manufacturing a secondary battery, comprising: an electrode assembly in which electrodes and separators are stacked alternately; and an electrode flange attached to each of the electrodes, the apparatus comprising: a cutting element disposed on one side of the electrode flange for movement toward the electrode flange in order to cut a portion to be cut from the electrode flange; and a joining die provided for crossing the cutting element on the other side of the electrode flange, wherein the cutting element comprises: a pressure surface configured to press the electrode flange; and an inclined surface provided in a position corresponding to the portion to be cut and extending at an angle away from the electrode flange from one end of the pressure surface. 2.The apparatus of claim 1, wherein one end of the inclined surface is shaped to be inwardly concave.
3. The apparatus of claim 1, wherein the inclined surface extends to be inclined at an angle of 30 degrees to 70 degrees.
4. The apparatus of claim 2, wherein one end of the joining die is arranged in a position corresponding to the portion to be cut from the electrode flange and is shaped to project outwardly convexly.
5. The apparatus of claim 1, further comprising a transfer portion coupled to the electrode flange below the electrode flange, wherein the joining die is arranged above the electrode flange, and the cutting element is provided below the electrode flange to move upward. 6.The apparatus of claim 1, wherein the secondary battery comprises a cylindrical secondary battery. 7.A method for manufacturing a secondary battery, comprising: an electrode assembly in which electrodes and separators are stacked alternately; and an electrode flange attached to each of the electrodes, the method comprising: an electrode flange cutting process of cutting a portion to be cut from the electrode flange; and an electrode flange joining process of joining the electrode flange to the electrode, wherein, in the electrode flange cutting process, a cutting element moves toward the electrode flange to cut the portion to be cut from the electrode flange, and the cutting element comprises: a pressure surface that presses the electrode flange; and an inclined surface provided in a position corresponding to the portion to be cut and extending at an angle away from the electrode flange from one end of the pressure surface. 8.The method of claim 7, wherein, in the process of cutting the electrode flange, the cutting element disposed below the electrode flange moves upward relative to the electrode flange to cut the electrode flange, and in the process of joining the electrode flange, the electrode flange is fixed to an upper side of the electrode.
9. A secondary battery comprising: an electrode assembly in which electrodes and separators are stacked alternately; an electrode flange attached to each of the electrodes; and a battery housing in which the electrode assembly and the electrode flange are housed, wherein a burr generated on an edge of the electrode flange due to cutting projects in a direction facing the battery housing. 10.The secondary battery of claim 9, wherein a corner of the electrode flange is curved with a radius of curvature in a plane.
11. The secondary battery of claim 10, wherein the corner of the electrode flange having the radius of curvature is disposed on the electrode.
12. The secondary battery of claim 10, wherein the radius of curvature of the corner of the electrode flange is greater than 1 / 2 the width of the electrode flange.
13. The secondary battery of claim 9, wherein the electrode assembly is wound in a state in which the electrodes and separators are stacked sequentially, and the battery casing is cylindrical and configured to accommodate the electrode assembly.