Method and apparatus for manufacturing unit cells

Abstract

The present invention provides an apparatus for manufacturing a unit cell, wherein a lower diaphragm and an upper diaphragm are continuously moved in a length direction, and in the process of manufacturing the unit cell, the lower diaphragm and the upper diaphragm are cut between electrodes adjacent to each other, and the unit cell is provided in a state in which the electrodes are stacked between the lower diaphragm and the upper diaphragm and on the upper diaphragm, respectively. The apparatus includes: a fixed part, which is arranged below the lower diaphragm and is heated to a predetermined temperature; a movable part, which is aligned with the fixed part in a vertical direction on the upper diaphragm; and a cutter, which is coupled to the movable part, is heated to a predetermined temperature, and is configured to cut the upper diaphragm and the lower diaphragm, wherein the lower diaphragm and the upper diaphragm are thermally fused between the fixed part and the movable part, and are cut by the cutter when passing between the fixed part and the movable part.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2020-0182657 filed on December 23, 2020, Korean Patent Application No. 10-2021-0002904 filed on January 8, 2021, and Korean Patent Application No. 10-2021-0161717 filed on November 22, 2021, the entireties of which are incorporated herein by reference.

[0002] The present invention relates to a method and apparatus for manufacturing a unit battery, and more particularly, to a method and apparatus for manufacturing a unit battery, wherein a lower separator and an upper separator are simultaneously bonded (sealed) and cut to prevent a secondary battery from short-circuiting due to adhesion of the separator and / or scattering of the electrode. Background Art

[0003] Currently, much research is being conducted on secondary batteries because, unlike primary batteries, they are rechargeable and have high potential for compact size and high capacity. With the development of technology and the increase in demand for mobile devices, the demand for secondary batteries as energy sources is rapidly increasing.

[0004] This secondary battery is constructed in a manner that an electrode assembly is embedded in a battery casing (e.g., a bag, a can, a shell, etc.). Due to the structure of the positive electrode / separator / negative electrode stack, the electrode assembly installed in the battery casing can be repeatedly charged and discharged. The electrode assembly is manufactured in various ways. However, generally, the electrode assembly can be manufactured in the following manner: after pre-preparing the unit cell 4, a plurality of unit cells 4 are stacked to manufacture the electrode assembly.

[0005] That is, see Figure 1a , which shows the state of manufacturing a unit cell according to the prior art. In the method of manufacturing a unit cell 4 according to the prior art, the positive electrode 1, the upper separator 3a, the negative electrode 2 and the lower separator 3b are respectively wound in the form of rolls and continuously unwound and supplied (however, the stacking positions of the positive electrode and the negative electrode may be different, and the separator, the positive electrode and the negative electrode may be stacked separately, or the separator may be set at the uppermost end instead of the positive electrode or the negative electrode being set at the uppermost end).

[0006] The separators 3 ( 3 a and 3 b ) are continuously supplied without disconnection, the negative electrode 2 is supplied between the upper separator 3 a and the lower separator 3 b , and the positive electrode 1 is supplied onto the upper separator 3 a .

[0007] Here, the separator 3 is continuously supplied without being cut. On the other hand, the positive electrode 1 and the negative electrode 2 are supplied in a state of being cut into predetermined sizes by respective cutters 6 and 7 .

[0008] The positive electrode 1 and the negative electrode 2 are paired and vertically stacked with an upper separator 3 a therebetween, and the upper separator 3 a is provided to be spaced a predetermined distance from the paired positive electrode 1 and negative electrode 2 adjacent to each other.

[0009] That is, the separator 3 is continuously connected, and the negative electrode 2 and the positive electrode 1 pass through the laminating device 9 in a state where the laminating device 9 is spaced a predetermined distance from the negative electrode 2 and the positive electrode 1. In the laminating device 9, heat and pressure are applied so that the negative electrode 2 and the positive electrode 1 are bent to the point of contact with the separator 3.

[0010] After the positive electrode 1 and the negative electrode 2 pass through the laminating device 9 in a state where the positive electrode 1 and the negative electrode 2 are bonded to the separator 3 , the separator 3 is cut to be provided as individual unit cells between the positive electrodes 1 and the negative electrodes 1 adjacent to each other.

[0011] That is to say, if Figure 1b As shown, it shows the shape of a cutter for cutting the separator. According to the prior art, after the electrodes 1 and 2 and the separator 3 are laminated (bonded) by applying heat and pressure, the separator 3 is cut between the electrodes adjacent to each other to manufacture individual unit cells 4.

[0012] However, the cutter 8 according to the related art has a structure that vertically applies pressure to cut the diaphragm 3. Therefore, when any one of the diaphragms 3a and 3b is not properly cut, there is a problem that the diaphragms 3a and 3b are folded in the direction of applying pressure.

[0013] After manufacturing the unit cells 4 , since a plurality of the unit cells 4 are stacked to manufacture an electrode assembly, folding of the separator 3 occurs, and thus, when a portion of the negative electrode 2 or the positive electrode 1 is exposed, a short circuit occurs inside the electrode assembly.

[0014] That is, see Figure 1a , the points where the separators 3a, 3b and the electrodes 1, 2 contact each other are flattened after passing through the press roller 5 by passing through the laminating device 9. However, in the structure according to the prior art, as Figure 1b As shown, the upper diaphragm 3a and the lower diaphragm 3b are not bonded but are spaced apart from each other, and therefore, there is a problem that the diaphragms are folded during cutting. Summary of the Invention

[0015] Technical issues

[0016] Therefore, the main object of the present invention is to provide a method and apparatus for manufacturing a unit cell, in which the cutting and sealing of the upper and lower separators are performed simultaneously, thereby preventing folding of the upper and lower separators and / or scattering of electrodes when cutting the separators.

[0017] Technical Solution

[0018] A device for manufacturing unit cells is provided in the present invention to achieve the aforementioned purpose, wherein a lower diaphragm and an upper diaphragm are continuously moved in a length direction, and in the process of manufacturing the unit cells, the lower diaphragm and the upper diaphragm are cut between electrodes adjacent to each other, and the unit cells are provided in a state where the electrodes are stacked between the lower diaphragm and the upper diaphragm and on the upper diaphragm at regular intervals, respectively. The device includes: a fixed component arranged below the lower diaphragm and heated to a predetermined temperature; a movable component aligned with the fixed component in a vertical direction on the upper diaphragm; and a cutter coupled to the movable component, heated to a predetermined temperature, and configured to cut the upper diaphragm and the lower diaphragm, wherein the lower diaphragm and the upper diaphragm are cut by the cutter and are heat-fused when passing between the fixed component and the movable component.

[0019] Each of the movable part and the fixed part may include a roller that rotates when the lower diaphragm and the upper diaphragm pass between the movable part and the fixed part, and the cutter may protrude from a surface of the movable part to press and cut the upper diaphragm and the lower diaphragm when the movable part rotates.

[0020] A plurality of cutters may be provided at regular intervals on the surface of the movable member.

[0021] Two cutters may be provided at intervals of 180 degrees from the center of the movable member, or four cutters may be provided at intervals of 90 degrees from the center of the movable member.

[0022] The cutter may be formed to form inclined surfaces on both sides so as to be symmetrical with each other, and ends where the inclined surfaces contact each other have a sharp shape.

[0023] The angle between the two inclined surfaces of the cutter may be 15° or more.

[0024] The cutter and the movable part may be configured to be integrated with each other. The fixed part may have a bar shape and be arranged to stand vertically below the lower diaphragm, the movable part may be arranged to stand vertically above the upper diaphragm so as to slide vertically downward, and the cutter may be integrally formed to have a sharp shape at the end of the movable part.

[0025] The movable member may be provided to be offset so that the movable member passes through the lower diaphragm and the upper diaphragm to face one surface of the fixed member and descend.

[0026] The end of the movable member may be formed so that the surface facing the fixed member is a flat surface and the opposing surface is an inclined surface, wherein the angle of the inclined surface may be 15° or greater. The angle of the inclined surface formed on the end of the movable member may be formed in a range of 15° to 120°.

[0027] Furthermore, the present invention provides a method for manufacturing a unit cell. A method for manufacturing a unit cell, the unit cell being provided in the present invention and in which a lower separator and an upper separator are continuously moved in a length direction, the lower separator and the upper separator being cut between electrodes adjacent to each other during the manufacturing process of the unit cell, the unit cell being provided in a state where the electrodes are stacked at regular intervals between the lower separator and the upper separator and on the upper separator, respectively, the method comprising: an electrode and separator transfer process for providing electrodes and separators, wherein the lower separator and the upper separator are continuously moved in a length direction, and the electrodes and the separator are arranged in a state where the electrodes are stacked at regular intervals between the lower separator and the upper separator; a cutter heating process for heating a cutter to a predetermined temperature, the cutter being coupled to an end of a movable part and sliding through the lower separator and the upper separator; and a cutting process, when the lower separator and the upper separator are arranged between the electrodes adjacent to each other at a sliding position of the cutter, the lower separator and the upper separator are cut by sliding the movable part, wherein when the cutter performs cutting, the heated cutter simultaneously heat-fuses the lower separator and the upper separator.

[0028] The fixed part can be arranged below the lower diaphragm and the movable part can be arranged above the upper diaphragm. During the cutting process, when the movable part descends through the upper and lower diaphragms, the fixed part can be arranged to be offset to support the lower diaphragm on the underside.

[0029] All movable parts, fixed parts and cutters may be heated to a predetermined temperature. For example, all fixed parts, movable parts and cutters may be heated to a temperature in the range of 60° C. to 250° C. Here, the cutter may be preferably heated to a temperature higher than that of the fixed parts.

[0030] The movable member may be configured such that one surface facing the fixed member at an end portion thereof is formed as a flat surface, and an inclined surface is formed on the other surface to have a sharp shape.

[0031] An angle between the flat surface and the inclined surface at the end of the movable member formed to have a sharp shape may be formed in the range of 15° to 120°.

[0032] The sliding speed of the movable part can be adjusted according to the heating temperature of the movable part and the fixed part. That is, when each of the movable part and the fixed part is heated to a relatively high temperature, the sliding speed of the movable part can be adjusted to be relatively faster, and when each of the movable part and the fixed part is heated to a relatively low temperature, the sliding speed of the movable part can be adjusted to be relatively slower.

[0033] The heating temperatures of the movable part and the fixed part can be adjusted according to the thickness of the lower diaphragm and the upper diaphragm.

[0034] Beneficial effects

[0035] According to the present invention having the above-described configuration, since the cutting of the diaphragm is performed by the cutter so that the diaphragm is sealed when cut, folding of the diaphragm and / or scattering of the electrodes can be suppressed.

[0036] The movable member may be heated to a predetermined temperature. Here, the movable member is heated to a temperature higher than that of the fixed member, so that instantaneous heat fusion can be achieved while cutting the inside of the diaphragm.

[0037] The movable part can be configured so that one surface facing the fixed part is flat and the other surface has a sharp edge. Furthermore, the movable part is limited to a specific angle range (15° to 120°), so when cutting, the heat fusion time, the contact area with the diaphragm, and the pressure applied to the diaphragm can be adjusted.

[0038] For example, if the angle of the movable member's end is less than 15°, the pressure applied to heat-fusing the diaphragm may reduce heat-fusing efficiency. On the other hand, if the angle exceeds 120°, the pressure applied to cutting the diaphragm may decrease, increasing the likelihood of cutting defects and unnecessary sealing areas. Therefore, in the present invention, the angle of the movable member's end is limited to a range of 15° to 120°, allowing simultaneous heat-fusing and cutting of the diaphragm.

[0039] Furthermore, the descending speed of the movable member can be adjusted according to the heating temperatures of the movable member and the fixed member or the angle of the end of the movable member due to the thickness of the diaphragm. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1a is a schematic diagram showing a state in which a unit cell is manufactured by a method according to the related art.

[0041] Figure 1b is a simplified side view showing the shape of a cutter for cutting a diaphragm according to the related art.

[0042] Figure 2 is a simplified view showing an apparatus for manufacturing unit batteries according to a first embodiment of the present invention.

[0043] Figure 3 is a view illustrating a rotation position of a cutter when an electrode is disposed between a fixed part and a movable part of the apparatus for manufacturing unit batteries according to the first embodiment of the present invention.

[0044] Figure 4 is a view illustrating a rotation position of a cutter when a separator is disposed between a fixed part and a movable part of the apparatus for manufacturing unit batteries according to the first embodiment of the present invention.

[0045] Figure 5 It shows Figure 4 An enlarged view of part C.

[0046] Figure 6 is a view showing a state just before a separator is cut by a cutter, which is integrally formed with a movable member, in an apparatus for manufacturing unit batteries according to a second embodiment of the present invention.

[0047] Figure 7 is a view showing a state when a cutter integrally formed with a movable member cuts a separator in an apparatus for manufacturing unit batteries according to a second embodiment of the present invention.

[0048] Figure 8 is a graph showing differences in adhesion distance (length of a portion where adhesion (sealing) is performed) and adhesion force between an upper separator and a lower separator according to an angle of a cutter in an apparatus for manufacturing unit batteries according to a second embodiment of the present invention.

[0049] Figure 9 are views showing the sequence of a method for manufacturing unit batteries, which method is applied to the apparatus for manufacturing unit batteries according to the present invention. DETAILED DESCRIPTION

[0050] Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the technical concept of the present invention. However, the present invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein.

[0051] In order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or like components throughout the specification.

[0052] Furthermore, the terms or words used in the present specification and claims should not be restrictively interpreted as ordinary meanings or dictionary-based meanings, but should be interpreted as meanings and concepts consistent with the scope of the present invention based on the principle that the inventor can appropriately define the concepts of the terms to best describe and explain his or her invention.

[0053] The present invention relates to an apparatus for manufacturing a unit cell in which electrodes 1 and 2 are stacked between a lower separator 3b and an upper separator 3a, and on the upper separator 3a, respectively, and when the separators 3 (3a and 3b) are cut, the sealing of the separator 3 is performed simultaneously. However, if two or more separators are provided, such as a unit cell in which the electrodes are stacked only between the lower separator 3b and the upper separator 3a and a unit cell in which a separator is additionally stacked on the uppermost electrode (in which three separators are stacked), the apparatus can be applied to the manufacture of all types of unit cells.

[0054] In the present invention, the apparatus for manufacturing a unit cell may replace the press roller 5 and the cutter 8 for cutting the separator 3, or may be replaced by a Figure 1a In the process shown, only the cutter 8 is replaced.

[0055] That is to say, in Figure 1a In the configuration of , the press roller 5 and the cutter 8 may be removed, or only the cutter 8 may be removed. Alternatively, the apparatus for manufacturing a unit battery provided in the embodiment of the present invention may be installed.

[0056] An apparatus for manufacturing unit batteries provided in the present invention is configured to include a fixed part, a movable part, and a cutter coupled to or integrally formed with the movable part.

[0057] Since the device for manufacturing unit batteries provided in the present invention is arranged at the position set in the cutter 8 according to the prior art, the lower separator 3b and the upper separator 3a are continuously moved in the length direction, and are arranged in a state where the positive electrode 1 and the negative electrode 2 are stacked between the lower separator 3b and the upper separator 3a and on the upper separator 3a, respectively, that is, the "positive electrode / upper separator / negative electrode / lower separator" or "negative electrode / upper separator / positive electrode / lower separator" are stacked in sequence from top to bottom.

[0058] Here, according to the present invention, a fixed component is positioned below the lower diaphragm 3b and can be selectively heated to a predetermined temperature. A movable component is aligned perpendicular to the fixed component from the upper diaphragm 3a and heated to a predetermined temperature. The cutter cuts the upper and lower diaphragms 3a and 3b while being heated by heat conducted from the movable component or directly heated.

[0059] In addition, when passing between the fixed member and the movable member, the lower diaphragm 3b and the upper diaphragm 3a may be thermally fused between the fixed member and the movable member and simultaneously cut by the cutter.

[0060] Hereinafter, embodiments according to the present invention will be described with reference to the accompanying drawings.

[0061] First embodiment

[0062] Figure 2is a simplified view showing an apparatus for manufacturing a unit battery according to a first embodiment of the present invention, Figure 3 is a view showing a rotational position of a cutter when an electrode is provided between a fixed part and a movable part of an apparatus for manufacturing unit batteries according to a first embodiment of the present invention, Figure 4 is a view showing a rotational position of a cutter when a separator is provided between a fixed part and a movable part of an apparatus for manufacturing unit batteries according to a first embodiment of the present invention, Figure 5 It shows Figure 4 Magnified view of portion C.

[0063] Referring to the drawings, in this embodiment, the movable member 20 and the fixed member 10 are each provided in the form of a roller that rotates when the lower diaphragm 3 b and the upper diaphragm 3 a pass between the movable member 20 and the fixed member 10 .

[0064] The movable part 20 and the fixed part 10 arranged in the form of a roller can each have a length equal to or greater than the width of each upper diaphragm 3a and lower diaphragm 3b so as to facilitate sealing and cutting in the width direction of the diaphragm 3 (3a and 3b), and can have a diameter that varies according to the number of cutters 30, the arrangement position, the size of each electrode 1 and 2, and the interval between the electrodes 1 and 2.

[0065] That is to say, if Figure 3 and Figure 4 As shown, the cutters 30 are provided at regular intervals on the surface of the movable part 20. The cutters 30 are configured so that when the electrodes 1 and 2 pass between the movable part 20 and the fixed part 10 ( Figure 3 The upper diaphragm 3a and the lower diaphragm 3b are arranged at a position spaced apart from the electrodes 1 and 2 without contacting the electrodes 1 and 2, and when the upper diaphragm 3a and the lower diaphragm 3b pass between the movable part 20 and the fixed part 10 ( Figure 4 The state in ( ) is set at a position where the upper diaphragm 3a and the lower diaphragm 3b are pressed.

[0066] Therefore, the diameter of the roller corresponding to the movable member 20 can be determined by taking into account the size and spacing of each of the electrodes 1 and 2. Furthermore, here, two cutters 30 may be arranged at intervals of 180 degrees from the center of the movable member 20, or four cutters 30 may be arranged at intervals of 90 degrees. Of course, in addition to two or four cutters, the cutters may be arranged in various numbers at regular intervals, provided that the diaphragms 3a and 3b can be cut without interfering with the electrodes 1 and 2.

[0067] In this embodiment, the cutter 30 is shaped so that inclined surfaces are formed on both sides so as to be symmetrical with each other, and ends where the inclined surfaces contact each other have a sharp shape.

[0068] Here, the angle A between the two inclined surfaces of the cutter 30 (see Figure 5 ) is formed to be 15° or greater. Preferably, the angle between the inclined surfaces is formed in the range of 15° to 120°.

[0069] The cutter 30 presses the upper diaphragm 3 a and the lower diaphragm 3 b in a state where heat generated in the movable member 20 is conducted and heated, or in a state where the cutter 30 is directly heated without passing through the movable member 20 .

[0070] Thus, the diaphragms 3a and 3b are cut at the points of contact with the cutter 30. Here, as the cutter 30 rotates, pressure is applied to the inclined surface, and heat and pressure are also applied to the lower fixing member 10. As a result, the diaphragms 3a and 3b are cut by the cutter 30 and simultaneously heat-fused together by the heat and pressure. Therefore, even after being cut, the upper diaphragm 3a and the lower diaphragm 3b are heat-fused at the cut points, thereby preventing them from collapsing.

[0071] If the angle A of the cutter 30 is formed too small, sufficient pressure is transmitted, so cutting is performed before thermal fusion is achieved, so it is preferably formed at an angle of 15° or greater as described above. However, this range may be further limited depending on the thickness or material of the diaphragm 3 or the moving speed of the diaphragm 3.

[0072] For reference, a heater (not shown) may be embedded in each of the movable part 20, the fixed part 10, and the cutter 30, or may be configured to conduct heat from an external heat source.

[0073] The movable member 20 and the fixed member 10 heated as described above can be heated within a range of 60°C to 250°C. The reason for limiting the temperature within the range of 60°C to 250°C is that, when the temperature is lower than 60°C, effective heat fusion of the diaphragm 3 is difficult to achieve, and when the temperature exceeds 250°C, the diaphragm 3 is melted, making it difficult to seal the diaphragm 3. Furthermore, the interval between the cutter 30 and the fixed member 10 can be selected within an appropriate range depending on the thickness and material of the diaphragm 3 and the moving speed of the diaphragm 3.

[0074] Furthermore, although the fixing member 10 is shown as a perfect circle in the drawings, the fixing member 10 may have a structure in which a groove is formed so that the end of the cutter 30 can be inserted, so that the pressure applied when the septum 3 contacts the fixing member 10 is increased or concentrated. Alternatively, when the end of the cutter 30 presses the septum 3, the fixing member 10 is made of a material having elasticity, or is configured to have an elastic layer stacked or applied on the surface so as to elastically support the septum 3.

[0075] In addition, an elastic body may be coupled or applied to the surface of the fixing member 10 to protect the diaphragm 3 when the fixing member is in contact with the diaphragm 3 .

[0076] Second embodiment

[0077] Figure 6 is a view showing a state just before a cutter cuts a separator in an apparatus for manufacturing unit batteries according to a second embodiment of the present invention, the cutter being integrally formed with a movable member, Figure 7 is a view showing a state when a cutter integrally formed with a movable member cuts a separator in an apparatus for manufacturing unit batteries according to a second embodiment of the present invention.

[0078] See also Figure 6 and Figure 7 , the fixed member 50 and the movable member 40 provided in this embodiment are each configured to have a rod shape.

[0079] The fixing member 50 is provided to stand vertically below the lower diaphragm 3 b , and an upper end of the fixing member 50 is configured to have a flat surface so as to support the lower side of the lower diaphragm 3 b .

[0080] Furthermore, the movable member 40 is provided so as to stand vertically on the upper diaphragm 3a and is configured to slide vertically downward. That is, the movable member 40 is coupled to a lifting device (not shown) so as to be lowered downward, thereby pressing the upper diaphragm 3a. Therefore, the movable member 40 provided in this embodiment can be configured as a piston sliding in a cylinder, a connecting rod device for converting rotational motion into linear motion, a gear device, etc.

[0081] The cutter 60 provided in this embodiment is provided as a structure integrally formed into a sharp shape at the end of the movable member 40. Alternatively, the cutter 60 may be provided in a shape coupled to be fixed to the end of the movable member 40 provided in the form of a rod.

[0082] In addition, as in the first embodiment, the fixed member 50 and the movable member 40 are heated by a heater or a separate heat source, and the cutter 60 is heated by receiving heat from the movable member 40 or by directly receiving heat from the heat source. The movable member 40 is provided so as to be offset so that the movable member 40 passes through the lower diaphragm 3b and the upper diaphragm 3a to face one surface of the fixed member 50 and descend.

[0083] That is, only the movable member 40 and the cutter 60 are heated, or the movable member 40, the cutter 60, and the fixed member 50 are heated to a predetermined temperature. For example, all of the fixed member 50, the movable member 40, and the cutter 60 may be heated within a range of 60° C. to 250° C. However, it is preferred that the cutter 60 be heated to a temperature higher than that of the fixed member 50.

[0084] Since the movable member 40 can pass through and press the cut surface of the diaphragm 3 and perform heat fusion by pressing, the heating temperature for achieving heat fusion can be changed depending on the descending speed. Therefore, it is heated to a temperature sufficient to achieve heat fusion as quickly as possible.

[0085] The movable member 40, cutter 60, and fixed member 50 heated as described above can be heated within a range of 60°C to 250°C. As described above, the temperature is limited to the range of 60°C to 250°C because, when the temperature is below 60°C, effective heat fusion of the diaphragm 3 is difficult to achieve, and when the temperature exceeds 250°C, the diaphragm 3 melts, making it difficult to seal the diaphragm 3. Furthermore, the spacing between the fixed member 50 and the movable member 40 can be selected within an appropriate range depending on the thickness and material of the diaphragm 3 and the speed of movement of the diaphragm 3, and can be continuously adjusted during the manufacturing process according to the heat fusion and cutting conditions.

[0086] In addition, an elastic body (not shown) may be coupled or applied to the surface of the fixing member 50 to protect the diaphragm 3 when the fixing member comes into contact with the diaphragm 3 .

[0087] In addition, in this embodiment, the cutter 60 is configured to have a sharp shape because one surface facing the fixed part 50 is formed as a flat surface and an inclined surface is formed on the other surface. Preferably, the angle B between the flat surface and the inclined surface at the end of the movable part 10 formed in the sharp shape is not limited but is formed in the range of 15° to 120°.

[0088] For example, if the angle of the end of the cutter 60 is less than 15°, the heat fusion efficiency may be reduced due to the pressure applied to the heat fusion of the diaphragm 3. On the other hand, if the angle exceeds 120°, the pressure applied to the cut diaphragm 3 may be reduced, thereby increasing the possibility of cutting defects. Therefore, in the present invention, the angle of the end of the cutter 60 is limited to a range of 15° to 120°, so that heat fusion with the diaphragm 3 and cutting can be performed simultaneously.

[0089] Therefore, when the cutting is performed within a range limited to a specific angle (15° to 120°), since the heat fusion time, the contact area with the diaphragm, the pressure applied to the diaphragm, etc. are adjusted, the descending speed of the movable part 40 can be adjusted according to the heating temperature of the movable part 40, the cutter 60 and the fixed part 50.

[0090] Figure 8 is a graph showing differences in adhesion distance (length of a portion where adhesion is performed) and adhesion force between upper and lower separators according to an angle of a cutter in an apparatus for manufacturing unit batteries according to a second embodiment of the present invention.

[0091] like Figure 8 As shown, as the angle B between the flat surface and the inclined surface increases, the bonding area between the separators 3a and 3b increases, the bonding distance (the length of the bonded portion) increases, and the bonding force also increases. As the bonding force increases, a more stable bond is maintained. However, if the bonding distance increases, the bonding force may act as a stress on the electrodes between the separators 3a and 3b, potentially applying excessive pressure to the separators 3a and 3b and causing damage. Consequently, the angle B between the flat surface and the inclined surface can be determined based on the thickness of each separator 3a and 3b or the size of the electrodes.

[0092] Furthermore, in order to ensure appropriate heat fusion time and cutting time, during the cutting process, when the movable member 40 slides to cut the lower diaphragm 3b and the upper diaphragm 3a, the conveyance of the electrode and the diaphragm may be stopped.

[0093] The present invention also provides a method for manufacturing a unit battery, which is applied to the above-mentioned device for manufacturing a unit battery.

[0094] Figure 9 are views showing the sequence of a method for manufacturing unit batteries, which method is applied to the apparatus for manufacturing unit batteries according to the present invention.

[0095] The method for manufacturing a unit cell provided in the present invention provides a method in which a lower separator 3b and an upper separator 3a are continuously moved in the length direction, and in the process of manufacturing a unit cell in which electrodes (positive and negative electrodes) are stacked between the lower separator 3b and the upper separator 3a and on the upper separator 3a, respectively, or in the process of manufacturing a unit cell in which electrodes are stacked only between the lower separator 3b and the upper separator 3a, the lower separator 3b and the upper separator 3a are cut and simultaneously heat-fused between electrodes adjacent to each other.

[0096] The method for manufacturing a unit cell according to the present invention includes a "process of conveying electrodes and separators (S1)", a "process of heating a cutter (S2)" and a "process of cutting a separator (S3)", and when the cutter cuts the separator 3, the lower separator 3b and the upper separator 3a are simultaneously thermally fused by the heated cutter.

[0097] In the process of conveying the electrodes 1 and 2 and the upper diaphragm 3a and the lower diaphragm 3b, the lower diaphragm 3b and the upper diaphragm 3a are continuously moved in the length direction by the laminating device 9 (see Figure 1A), and the electrodes 1 and 2 and the diaphragm 3 are provided in a state where the electrodes are stacked between the lower diaphragm 3b and the upper diaphragm 3a and on the upper diaphragm 3a, respectively.

[0098] In the process of heating the cutter, before cutting the diaphragm 3, the cutter (or a movable member capable of transferring heat to the cutter) that slides to cut the lower and upper diaphragms 3b is heated to a predetermined temperature.

[0099] Furthermore, in the cutting process, when the lower diaphragm 3b and the upper diaphragm 3a are placed between the electrodes adjacent to the sliding position of the cutter, the cutter is slid to cut the lower diaphragm 3b and the upper diaphragm 3a.

[0100] Here, when the movable members 20 and 40 are slid so that the cutters 30 and 60 come into contact with the diaphragm 3, the diaphragm 3 is heated and pressed so that the lower diaphragm 3b and the upper diaphragm 3a are simultaneously thermally fused.

[0101] Only the "cutter" or all of the "fixed part, movable part, and cutter" are heated to a predetermined temperature. For example, all of the fixed part, movable part, and cutter may be heated within a range of 60°C to 250°C.

[0102] That is, since the cutter can pass through and press the cut surface of the diaphragm 3, and heat fusion is performed by pressing, the heating temperature for achieving heat fusion can be changed depending on the descending speed. Therefore, it is heated to a temperature sufficient to achieve heat fusion as quickly as possible.

[0103] The descending speed can be adjusted according to the heating temperature of the movable part and the fixed part.

[0104] That is, when each of the movable member and the fixed member is heated to a relatively high temperature (or according to the heating temperature of the cutter), the sliding speed of the movable member can be adjusted to relatively increase, and when each of the movable member and the fixed member is heated to a relatively low temperature, the sliding speed of the movable member can be adjusted to relatively decrease. Here, the sliding speed of the movable member refers to the rotation speed when the movable member has a roller shape as in the first embodiment, and the descending speed when the movable member has a rod shape as in the second embodiment.

[0105] When the movable member and the fixed member (including the cutter) are sufficiently heated, the sliding speed of the movable member can be maximized to increase the production speed because the thermal fusion between the diaphragms 3a and 3b is quickly achieved. On the other hand, if the heating is insufficient, the sliding speed of the movable member can be appropriately slowed down to ensure the time taken to complete the thermal fusion.

[0106] Furthermore, the heating temperatures of the movable member and the fixed member and / or the sliding speed of the movable member can be adjusted according to the thicknesses of the lower diaphragm 3b and the upper diaphragm 3a.

[0107] In the present invention having the configuration described above, since the heated cutter cuts the diaphragms 3a and 3b and sealing of the diaphragms 3a and 3b is performed at the time of cutting, the occurrence of folding of the diaphragms 3a and 3b can be suppressed.

[0108] All fixed parts, movable parts and cutters can be heated to a predetermined temperature. Here, each of the movable parts and the cutter can be heated to a temperature higher than that of the fixed parts, so that instantaneous heat fusion can be achieved while cutting the inside of the diaphragm.

[0109] The end of the cutter can be limited to a specific angle (15° to 120°), and therefore, when cutting, the heat fusion time, the contact area with the diaphragm 3, the pressure applied to the diaphragm, etc. can be adjusted.

[0110] For example, when the angle of the cutter tip is less than 15°, the heat-fusing efficiency may be reduced due to the pressure acting on the heat-fusing of the diaphragm 3. On the other hand, when the angle exceeds 120°, the pressure acting on the cut diaphragm 3 may be reduced, thereby increasing the possibility of cutting defects. Therefore, in the present invention, the angle of the cutter tip is limited to the range of 15° to 120°, so that heat-fusing with the diaphragm 3 and cutting can be performed simultaneously.

[0111] While embodiments of the present invention have been described with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention as defined in the following claims.

[0112] [Explanation of symbols]

[0113] 1: Positive electrode

[0114] 2: Negative electrode

[0115] 3: Diaphragm (3a: upper diaphragm, 3b: lower diaphragm)

[0116] 10,50:Fixed parts

[0117] 20, 40: movable parts

[0118] 30, 60: Cutter

Claims

1. An apparatus for manufacturing a unit cell, wherein a lower separator and an upper separator are continuously moved in a length direction, and during the manufacturing process of the unit cell, the lower separator and the upper separator are cut between electrodes adjacent to each other, the unit cell being provided in a state in which the electrodes are stacked at regular intervals between the lower separator and the upper separator and on the upper separator, respectively, the apparatus comprising: a fixing member disposed below the lower diaphragm and heated to a predetermined temperature; a movable member vertically aligned with the fixed member on the upper diaphragm; as well as a cutter coupled to the movable member, heated to a predetermined temperature, and configured to cut the upper diaphragm and the lower diaphragm, wherein the lower diaphragm and the upper diaphragm are cut and thermally fused by the cutter when passing between the fixed component and the movable component, wherein the fixing member has a rod shape and is arranged to stand vertically below the lower diaphragm, The movable member is arranged to stand vertically above the upper diaphragm so as to slide vertically downward, and The cutter is integrally formed to have a sharp shape at an end portion of the movable member, and The movable member is arranged to be staggered so that the movable member passes through the lower diaphragm and the upper diaphragm to face one surface of the fixed member and descend.

2. The device according to claim 1, wherein each of the movable member and the fixed member comprises a roller that rotates when the lower diaphragm and the upper diaphragm pass between the movable member and the fixed member, and The cutter protrudes from a surface of the movable member to press and cut the upper diaphragm and the lower diaphragm when the movable member rotates.

3. The device according to claim 2, wherein a plurality of cutters are provided at regular intervals on the surface of the movable member.

4. The device according to claim 3, wherein two cutters are provided at intervals of 180 degrees from the center of the movable member.

5. The device according to claim 3, wherein four cutters are provided at intervals of 90 degrees from the center of the movable member. 6 . The device according to claim 2 , wherein the cutter is formed with inclined surfaces formed on both sides so as to be symmetrical with each other, and ends of the inclined surfaces contacting each other have a sharp shape.

7. The device according to claim 2, wherein an angle between two inclined surfaces of the cutter is 15° or greater.

8. The device according to claim 1, wherein the end portion of the movable member is formed so that a surface facing the fixed member is a flat surface and an opposite surface is an inclined surface, in, The angle of the inclined surface is 15° or greater. 9 . The device according to claim 8 , wherein the angle of the inclined surface formed on the end portion of the movable member is formed in a range of 15° to 120°.

10. A method for manufacturing a unit cell, wherein a lower separator and an upper separator are continuously moved in a length direction, and in a process of manufacturing the unit cell, the lower separator and the upper separator are cut between electrodes adjacent to each other, the unit cell being provided in a state where electrodes are stacked at regular intervals between the lower separator and the upper separator and on the upper separator, the method comprising: an electrode and diaphragm conveying step of providing electrodes and diaphragms, wherein the lower diaphragm and the upper diaphragm are continuously moved in a length direction, and the electrodes and diaphragms are provided in a state where the electrodes are stacked at regular intervals between the lower diaphragm and the upper diaphragm; a cutter heating step of heating a cutter to a predetermined temperature, the cutter being coupled to an end portion of the movable member and sliding to pass through the lower diaphragm and the upper diaphragm; as well as a cutting step of cutting the lower diaphragm and the upper diaphragm by the cutter by sliding the movable member when the lower diaphragm and the upper diaphragm are disposed between the electrodes adjacent to each other at a sliding position of the cutter, wherein, when the cutting process is performed by the cutter, the heated cutter simultaneously heat-fuses the lower diaphragm and the upper diaphragm, and wherein the fixed part is arranged below the lower diaphragm, the movable part is arranged above the upper diaphragm, and In the cutting process, when the movable member descends to pass through the upper diaphragm and the lower diaphragm, the fixing member is disposed to be offset so as to support the lower diaphragm at a lower side.

11. The method according to claim 10, wherein all of the movable parts, the fixed parts and the cutter are heated to a predetermined temperature.

12. The method of claim 11, wherein all of the fixed parts, the movable parts and the cutter are heated in the range of 60°C to 250°C.

13. The method of claim 11, wherein the cutter is heated to a temperature higher than a temperature of the fixing member. 14 . The method according to claim 10 , wherein the movable member is configured such that one surface facing the fixed member at an end portion thereof is formed as a flat surface, and an inclined surface is formed on the other surface to have a sharp shape. 15 . The method according to claim 14 , wherein an angle between the flat surface and the inclined surface at the end of the movable member formed to have a sharp shape is formed in a range of 15° to 120°.

16. The method according to claim 12, wherein a sliding speed of the movable member is adjusted according to heating temperatures of the movable member and the fixed member.

17. The method according to claim 16, wherein when each of the movable member and the fixed portion is heated to a relatively high temperature, the sliding speed of the movable member is adjusted to be relatively increased, and When each of the movable member and the fixed member is heated to a relatively low temperature, the sliding speed of the movable member is adjusted to be relatively reduced.

18. The method according to claim 12, wherein heating temperatures of the movable part and the fixed part are adjusted according to thicknesses of the lower diaphragm and the upper diaphragm.

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