Baffle cutting apparatus and baffle cutting method

Abstract

The separator cutting device (100) includes: a conveying section (102) that conveys a continuous body (W) of separators (Wa); a tension imparting mechanism (104) that imparts tension to at least a portion of the continuous body (W) in a conveying direction (A) of the continuous body (W); and a laser irradiation section (106) that irradiates the portion of the continuous body (W) to which the tension imparting mechanism (104) imparts the tension with laser light (L) to singulate the portion into a plurality of separators (Wa).

Description

Technical Field

[0001] This disclosure relates to a partition cutting device and a partition cutting method. Background Technology

[0002] For use in vehicles and other applications, laminated batteries have been developed. These batteries have a structure in which multiple positive and negative electrodes, sandwiched between separators, are alternately stacked, and an electrolyte is contained within a container. The formation of the laminated electrodes sometimes involves cutting continuous separators into single sheets. For example, Patent Document 1 discloses a cutting device that irradiates a strip-shaped separator substrate (a continuous separator) with a laser, thus single-sheeting it into a rectangular separator.

[0003] [Prior Technology Documents]

[0004] [Patent Literature]

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-72785 Summary of the Invention

[0006] [The problem the invention aims to solve]

[0007] In recent years, with the increasing popularity of electric vehicles and portable devices, battery shipments have shown a tendency to increase, requiring improvements in battery production preparation time and production volume. Therefore, there is a demand to shorten the cutting time of the separator continuous body. Increasing the laser scanning speed is considered as a method to shorten the cutting time. However, increasing the laser scanning speed reduces the energy density imparted to the cutting section of the continuous body, making cutting more difficult. In contrast, increasing the laser output intensity is considered, but this would require more expensive laser equipment, potentially increasing costs.

[0008] This disclosure was made in view of the following situation, and one of its objectives is to provide a technique for increasing the cutting time of the diaphragm continuum without relying on the output intensity of the laser.

[0009] [Technical solutions used to address technical problems]

[0010] One aspect of this disclosure is a separator cutting device. The device includes: a conveying section for conveying a continuous body of separators for batteries; a tension applying mechanism for applying tension to at least a portion of the continuous body along the conveying direction of the continuous body; and a laser irradiation section for isolating a portion of the continuous body that has been tensioned by the tension applying mechanism into multiple separators by irradiating it with a laser.

[0011] One aspect of this disclosure is a separator cutting method. The method includes the following steps: conveying a continuous body of separators for a battery; applying tension to at least a portion of the continuous body along the conveying direction of the continuous body; and irradiating the tensioned portion of the continuous body with a laser to monolithize it into multiple separators.

[0012] Any combination of the above-mentioned constituent elements, as well as any scheme that transforms the manifestation of this disclosure among methods, apparatus, systems, etc., is also valid as a scheme of this disclosure.

[0013] [Invention Effects]

[0014] According to this disclosure, the cutting time of the continuous section of the partition can be shortened without relying on the increase of the laser output intensity. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a device for manufacturing stacked electrode bodies.

[0016] Figure 2 This is a schematic diagram of a portion of the partition cutting device in an embodiment. Detailed Implementation

[0017] The present disclosure will now be described based on preferred embodiments and with reference to the accompanying drawings. These embodiments are not intended to limit the present disclosure but are merely illustrative, and all features and combinations thereof described in the embodiments may not be essential to the present disclosure. Identical or equivalent constituent elements, components, and processes shown in the various drawings are labeled with the same reference numerals, and repetitive descriptions are omitted where appropriate. Furthermore, for ease of explanation, the scale and shape of the parts shown in the figures are conveniently set and are not to be interpreted limitingly unless specifically mentioned. Additionally, when terms such as "first" and "second" are used in this specification or claims, unless specifically mentioned, these terms do not indicate any order or importance, but are used to distinguish one configuration from others. Furthermore, in the various drawings, parts of components that are not important in describing the embodiments are omitted.

[0018] Figure 1 This is a schematic diagram of a stacked electrode manufacturing apparatus 1. As an example, the stacked electrode manufacturing apparatus 1 is a continuous drum-type manufacturing apparatus that combines multiple drums. By performing various processes such as cutting, heating, bonding, and stacking of electrode bodies and separators through the drums, stacked electrodes can be manufactured at high speed and continuously. Stacked electrodes are used, for example, in lithium-ion secondary batteries. However, the structure of the stacked electrode manufacturing apparatus 1 is not limited to a continuous drum type.

[0019] The stacked electrode manufacturing apparatus 1 includes: a first electrode cutting drum 2, a first electrode heating drum 4, a second electrode cutting drum 6, a second electrode heating drum 8, an adhesive drum 10, a partition cutting drum 12, and a stacking drum 14.

[0020] The first electrode cutting drum 2 is a drum that cuts a continuous body of multiple first electrode plates, monolithically divides them into multiple first electrode plates, and transports them. In this embodiment, the first electrode is the negative electrode. A strip-shaped first electrode continuous body N, which is a continuous body of multiple first electrode plates, is supplied to the first electrode cutting drum 2. The first electrode continuous body N has a first electrode current collector and a first electrode active material layer. The first electrode active material layer is stacked on the first electrode current collector. In this embodiment, the first electrode active material layer is stacked on both sides of the first electrode current collector, but it is also possible to stack the first electrode active material layer only on one side of the first electrode current collector.

[0021] Both the first electrode current collector and the first electrode active material layer can be made of known materials and have known structures. The first electrode current collector is, for example, a foil or porous body made of copper or aluminum. The first electrode active material layer is, for example, formed by coating a first electrode composite material slurry containing the first electrode active material, a binder, and a dispersant onto the surface of the first electrode current collector, and then drying and rolling the coating. The thickness of the first electrode current collector is, for example, 3 μm or more and 50 μm or less. The thickness of the first electrode active material layer is, for example, 10 μm or more and 100 μm or less.

[0022] The first electrode cutting drum 2 has a plurality of holding heads arranged along the circumferential direction of the drum and a cutting blade for cutting the first electrode continuous N. The plurality of holding heads have holding surfaces for adsorbing and holding the first electrode continuous N. The holding surfaces of each holding head face the outside of the first electrode cutting drum 2. The first electrode continuous N supplied to the first electrode cutting drum 2 is conveyed by the rotation of the first electrode cutting drum 2 while being adsorbed and held by the holding surfaces of the plurality of holding heads.

[0023] Multiple holding heads rotate about the central axis of the first pole cutting drum 2, and can move independently of each other along the circumference of the drum. The relative movement of each holding head is achieved by a motor mounted on each holding head, which is different from the motor that rotates the first pole cutting drum 2. By independently driving the holding heads, it is possible to adjust the cutting position of the cutting blade on the first pole continuous N, adjust the position of the monolithized first pole plate, etc.

[0024] The first electrode cutting drum 2 adsorbs and holds the supplied first electrode continuous N and rotates it for transport. Figure 1 The first electrode continuum N is cut at the schematic cutting position 16. The first electrode continuum N is cut by the cutting blade at the position between adjacent holding heads, and is monolithically divided into multiple first electrode plates. The resulting first electrode plates are transported while being held in adsorption at their respective holding heads. The positions of the multiple first electrode plates generated are monitored by a camera or the like.

[0025] The first electrode heating drum 4 is positioned close to the first electrode cutting drum 2. The holding head of the first electrode cutting drum 2 temporarily accelerates or decelerates near its proximity to the first electrode heating drum 4 until its linear velocity is approximately the same as that of the first electrode heating drum 4. Thus, the relative velocity between the holding head and the first electrode heating drum 4 is approximately zero. At a time when the relative velocity is approximately zero, the holding head discharges the adsorbed and held first electrode plate towards the first electrode heating drum 4.

[0026] The first electrode heating drum 4 holds and rotates the first electrode plate discharged from the first electrode cutting drum 2, preheating it via a built-in heater. This preheating is performed to thermally bond the separator to the first electrode plate in a subsequent bonding process. In this embodiment, the first electrode plate is heated at heating position 18, but this is not a limitation; for example, the first electrode plate can be heated over the entire circumferential area of ​​the first electrode heating drum 4.

[0027] The second electrode cutting drum 6 is a drum that cuts a continuous body of multiple second electrode plates, monolithically divides them into multiple second electrode plates, and transports them. In this embodiment, the second electrode is the positive electrode. A strip-shaped second electrode continuous body P, which is a continuous body of multiple second electrode plates, is supplied to the second electrode cutting drum 6. The second electrode continuous body P has a second electrode current collector and a second electrode active material layer. The second electrode active material layer is stacked on the second electrode current collector. In this embodiment, the second electrode active material layer is stacked on both sides of the second electrode current collector, but it is also possible that the second electrode active material layer is stacked only on one side of the second electrode current collector.

[0028] Both the second current collector and the second active material layer can be made of known materials and have known structures. The second current collector is, for example, a foil or porous body made of stainless steel or aluminum. The second active material layer is, for example, formed by coating a second-electrode composite material slurry containing the second active material, a binder, and a dispersant onto the surface of the second current collector, followed by drying and rolling the coating. The thickness of the second current collector is, for example, 3 μm or more and 50 μm or less. The thickness of the second active material layer is, for example, 10 μm or more and 100 μm or less.

[0029] The second-pole cutting drum 6 has a plurality of holding heads arranged along the circumferential direction of the drum and a cutting edge for cutting the second-pole continuous P. The plurality of holding heads have holding surfaces that hold and adhere the second-pole continuous P. The holding surfaces of each holding head face the outer side of the second-pole cutting drum 6. The second-pole continuous P, supplied to the second-pole cutting drum 6, is conveyed by the rotation of the second-pole cutting drum 6 while being held and adhered to the holding surfaces of the plurality of holding heads.

[0030] Multiple holding heads rotate about the central axis of the second-pole cutting drum 6, and can move independently relative to each other along the circumference of the drum. The relative movement of each holding head is achieved by a motor mounted on each holding head, which is different from the motor that rotates the second-pole cutting drum 6. By independently driving the holding heads, it is possible to adjust the cutting position of the cutting blade on the second-pole continuous P, adjust the position of the monolithized second-pole plate, etc.

[0031] The second-stage cutting drum 6 adsorbs and holds the supplied second-stage continuous body P and rotates it for transport. Figure 1 The cutting position 20, schematically shown, cuts the second electrode continuum P. The second electrode continuum P is cut by a cutting blade at a position between adjacent holding heads, and is monolithically divided into multiple second electrode plates. The resulting second electrode plates are transported while being held in place by their respective holding heads. The positions of the generated multiple second electrode plates are monitored using a camera or the like.

[0032] The second electrode heating drum 8 is positioned close to the second electrode cutting drum 6. The holding head of the second electrode cutting drum 6 temporarily accelerates or decelerates near its proximity to the second electrode heating drum 8 until its linear velocity is approximately the same as that of the second electrode heating drum 8. Thus, the relative velocity between the holding head and the second electrode heating drum 8 is approximately zero. At a time when the relative velocity is approximately zero, the holding head discharges the adsorbed and held second electrode plate towards the second electrode heating drum 8.

[0033] The second electrode heating drum 8 holds and rotates the second electrode plate discharged from the second electrode cutting drum 6, preheating it via a built-in heater. This preheating is performed to thermally bond the separator to the second electrode plate in a subsequent bonding process. In this embodiment, the second electrode plate is heated at heating position 22, but this is not a limitation; for example, the second electrode plate can be heated over the entire circumferential area of ​​the second electrode heating drum 8.

[0034] The bonding drum 10 is a drum that forms a continuous laminate 26 of multiple unit laminates. Each unit laminate consists of a first partition, a first electrode plate, a second partition, and a second electrode plate. Multiple strip-shaped continuous strips of first partition S1 and multiple strip-shaped continuous strips of second partition S2 are supplied to the bonding drum 10. A thermally adhesive layer is provided on the surface of each of the first partition continuous strips S1 and the second partition continuous strips S2. The thermally adhesive layer has the property of not exhibiting adhesiveness at room temperature but exhibiting adhesiveness upon heating. For example, the thermally adhesive layer is a thermoplastic layer containing a thermoplastic polymer, exhibiting adhesiveness based on the plastic deformation of the thermoplastic polymer caused by heating.

[0035] Furthermore, the bonding drum 10 is positioned close to the first electrode heating drum 4 and the second electrode heating drum 8. Multiple first electrode plates are supplied to the bonding drum 10 from the first electrode cutting drum 2 via the first electrode heating drum 4, and multiple second electrode plates are supplied to the bonding drum 10 from the second electrode cutting drum 6 via the second electrode heating drum 8. The first electrode plates are preheated by the first electrode heating drum 4 while being rotated and conveyed, and are discharged towards the bonding drum 10 at a position where the first electrode heating drum 4 is close to the bonding drum 10. The second electrode plates are preheated by the second electrode heating drum 8 while being rotated and conveyed, and are discharged towards the bonding drum 10 at a position where the second electrode heating drum 8 is close to the bonding drum 10.

[0036] The first partition continuous S1, the first electrode plate, the second partition continuous S2, and the second electrode plate are arranged in the listed order relative to the adhesive drum 10 from the upstream side of the direction of rotation of the adhesive drum 10. Therefore, the first partition continuous S1 is first supplied to the adhesive drum 10 at a predetermined position. The first partition continuous S1 is held in place by the adhesive drum 10 and is rotated and conveyed. Next, the first electrode plate is supplied from the first electrode heating drum 4 to the adhesive drum 10 at a position downstream of the first partition continuous S1 and placed on the first partition continuous S1. A plurality of first electrode plates are arranged on the first partition continuous S1 at predetermined intervals in the conveying direction of the first partition continuous S1.

[0037] Next, a second partition plate continuous body S2 is supplied to the bonding drum 10 at a position downstream of the first electrode plate supply position and placed on top of the plurality of first electrode plates. Then, at a position downstream of the second partition plate continuous body S2 supply position, the first partition plate continuous body S1, the plurality of first electrode plates, and the second partition plate continuous body S2 are pressed together by the hot pressing roller 24, bonding them together. Next, at a position downstream of the pressing position of the hot pressing roller 24, a second electrode plate is supplied from the second electrode heating drum 8 to the bonding drum 10 and placed on top of the second partition plate continuous body S2. The plurality of second electrode plates are arranged at predetermined intervals on the second partition plate continuous body S2 in the conveying direction of the second partition plate continuous body S2. Furthermore, the plurality of second electrode plates are bonded to the second partition plate continuous body S2 by the pressing pressure of the second electrode heating drum 8.

[0038] Through the above processes, the first separator continuous body S1, multiple first electrode plates, the second separator continuous body S2, and multiple second electrode plates are sequentially stacked and bonded to form a continuous laminate 26. The continuous laminate 26 has a structure in which unit laminates composed of the first separator, the first electrode plate, the second separator, and the second electrode plate are connected by the first separator continuous body S1 and the second separator continuous body S2. The continuous laminate 26 is conveyed from the bonding drum 10 to the separator cutting drum 12. Furthermore, since the second electrode plates are not supplied from the second electrode cutting drum 6 side, unit laminates with a three-layer structure excluding the second electrode plates can also be generated at regular intervals. Additionally, the electrode plate that is not supplied can also be the first electrode plate.

[0039] The partition cutting drum 12 is used to cut the first partition continuous body S1 and the second partition continuous body S2 of the continuous laminate 26, breaking them down into multiple unit laminates. The partition cutting drum 12 holds the continuous laminate 26 by means of multiple holding heads arranged along the circumference of the drum, and transports it by the rotation of the drum. Figure 1 The continuous laminate 26 is cut at the schematic cutting position 28. The continuous laminate 26 is cut between adjacent holding heads and is monolithized into multiple unit laminates. At this time, the first partition continuous S1 and the second partition continuous S2 of the continuous laminate 26 are cut between adjacent electrode plates in the transport direction of the continuous laminate 26.

[0040] The resulting unit stacks are conveyed while being held in place by the holding heads. The holding heads discharge the held unit stacks toward the stacking drum 14. The positions of the generated unit stacks are monitored by a camera or the like. The structure of the septum cutting drum 12 will be described in detail later.

[0041] The stacking drum 14 is a drum in which multiple unit stacks are stacked on the stacking stage 30 to form a stacked electrode body. The stacking drum 14 has multiple stacking heads arranged along the circumference of the drum. Each stacking head has a holding surface that adsorbs and holds the unit stack. The holding surface of each stacking head faces the outer side of the stacking drum 14. The multiple stacking heads rotate around the central axis of the stacking drum 14 and proceed sequentially to a stacking position opposite to the stacking stage 30. The stacking head that reaches the stacking position discharges the held unit stack towards the stacking stage 30.

[0042] The stacking stage 30 is positioned directly below the stacking drum 14. Unit laminates discharged from each stacking head of the stacking drum 14 are sequentially stacked on the stacking stage 30, thereby forming a stacked electrode body. The stacking stage 30 can be driven in mutually orthogonal X-axis and Y-axis directions. Furthermore, the stacking stage 30 can adjust its tilt angle in the XY plane. This adjusts the position and tilt angle of the unit laminates discharged from the stacking drum 14 relative to the unit laminates already stacked on the stacking stage 30 in the X-axis and Y-axis directions.

[0043] The partition cutting drum 12 is composed of the partition cutting device 100 of this embodiment. Figure 2 This is a schematic diagram of a portion of the partition cutting device 100 according to an embodiment. Furthermore, in Figure 2 In the middle, it represents the state of the perspective continuum W. The partition cutting device 100 includes a conveying unit 102, a tension applying mechanism 104, and a laser irradiation unit 106.

[0044] The conveying unit 102 conveys a continuous body W of the separator Wa for the battery. When the separator cutting device 100 constitutes a separator cutting drum 12, the continuous body W corresponds to the first separator continuous body S1 and the second separator continuous body S2 in the continuous laminate 26. Furthermore, the separator Wa corresponds to the first separator and the second separator in a unit laminate. Alternatively, the continuous body W can also be a single first separator continuous body S1 and a second separator continuous body S2.

[0045] The conveying section 102 of this embodiment has a plurality of holding heads 108 and a drum section 110. The plurality of holding heads 108 hold the continuous body W. Each holding head 108 has a holding surface 112 for holding the continuous body W. For example, the holding surface 112 has an attraction mechanism for attracting atmospheric gases such as air, and is capable of adsorbing and holding the continuous body W.

[0046] The drum section 110 is disc-shaped (see reference). Figure 1 Multiple retaining heads 108 are arranged at approximately equal intervals on the circumference. Furthermore, in Figure 2 The drum section 110 is schematically shown as having a flat shape. When arranged in the drum section 110, the holding surfaces 112 of each holding head 108 face outward in the radial direction of the drum section 110. The drum section 110 is connected to a drive mechanism (not shown) such as a motor on its central axis, and is capable of rotating around the central axis.

[0047] The drum 110 rotates, causing each holding head 108 to move toward the cutting position 28 and pass through it. This allows the continuous body W to be continuously transported to the cutting position 28. The cutting position 28 is the position opposite the drum 110 to the laser irradiation unit 106 (more precisely, the exit port from which the laser L is emitted into the drum 110).

[0048] The tension applying mechanism 104 applies tension to at least a portion of the continuous body W along the conveying direction A of the continuous body W. In this embodiment, the tension applying mechanism 104 displaces two adjacent holding heads 108 relative to each other in the circumferential direction of the drum 110, widening the distance between these two holding heads 108, thereby applying tension to the continuous body W in the conveying state. For example, the tension applying mechanism 104 makes the distance G1 between two holding heads 108 arranged at the cutting position 28 wider than the distance G2 between two holding heads 108 arranged in other areas. This applies tension to the portion of the continuous body W at the cutting position 28.

[0049] To achieve this tension application, the tension applying mechanism 104 includes multiple motors 114 provided on each holding head 108 and a control unit 116 that controls the driving of each motor 114. Known stepper motors or the like can be used as the motors 114. Each holding head 108 is connected to the drum 110 via a motor 114. Each motor 114 causes each holding head 108 to move independently of the movement caused by the rotation of the drum 110. Therefore, each holding head 108 rotates about the central axis of the drum 110 due to the rotation of the drum 110, and can move independently of the other holding heads 108 along the circumferential direction of the drum 110 by the drive of the motors 114.

[0050] The control unit 116 controls the drive of the motor 114 located at the corresponding holding head 108 by increasing the interval G1 between the two adjacent holding heads 108 separated by the cutting position 28. Figure 2 The control unit 116 is described as a functional module. This functional module is implemented as hardware by components and circuits, such as a computer's CPU and memory, and as software by computer programs. Those skilled in the art will understand that these functional modules can be implemented in various forms through a combination of hardware and software. The control unit 116 can control the drive of each motor 114 based on a pre-set action program.

[0051] For example, multiple holding heads 108 are arranged at intervals G2 to hold and hold the continuous body W. Furthermore, the holding head 108 reaching the cutting position 28 passes through the cutting position 28 at a faster speed than the subsequent holding head 108. Therefore, the interval G1 between two holding heads 108 arranged at the cutting position 28 is wider than the interval G2 between two holding heads 108 arranged in other areas. As a result, tension is applied to the portion of the continuous body W extending at the cutting position 28 during the conveying process.

[0052] Furthermore, the expansion of the spacing between two adjacent holding heads 108 can also be achieved through a cam mechanism including a cam groove and a protrusion, wherein the cam groove does not follow the rotation of the drum 110, and the protrusion is provided on each holding head 108 and engages with the cam groove. Alternatively, it can be configured such that the tension applying mechanism 104 applies tension to the continuous body W before it is supplied to the conveying section 102, and the conveying section 102 conveys the continuous body W while maintaining the tension. In this case, the tension applying mechanism 104 can be, for example, a combination of clamping rollers, suction rollers, tension adjusting rollers, etc., provided on the supply line that supplies the continuous body W to the conveying section 102.

[0053] Furthermore, the conveying section 102 is not limited to a roller type that conveys the continuous body W along the circumferential direction of the drum 110; for example, it can also be a platform type that conveys along the horizontal direction. In this case, the tension applying mechanism 104 can also be composed of a combination of clamping rollers, suction rollers, tension adjusting rollers, etc., provided in the conveying section 102.

[0054] Furthermore, the tension-applying mechanism 104 can also apply tension to the portion of the continuous body W other than the portion extending at the cut position 28. For example, tension can also be applied to the entire continuous body W by an unwinding device located at the upstream end of the conveyor line of the continuous body W and a winding device located at the downstream end. However, as in this embodiment, applying tension locally and independently of the tension applied to the continuous body W during conveying allows for more reliable and simpler application of the desired tension to the portion of the continuous body W extending at the cut position 28, and is therefore more preferable.

[0055] The tension per unit area applied to a cross-section perpendicular to the conveying direction A of the continuous body W is preferably 1.9 N / mm. 2 The above, and more preferably, is 2.9 N / mm 2 The above, and more preferably, is 3.8 N / mm 2 The above, and even more preferably, is 4.8 N / mm. 2 That's all. By setting the tension to 1.9 N / mm. 2 In summary, when the irradiation conditions of laser L are set, for example, an output of 100W and a scanning speed of 5000mm / s, the continuous body W can be cut more easily. Furthermore, the inventors have confirmed that the continuous body W cannot be cut when no tension is applied to it under the same irradiation conditions (except for the tension applied to the continuous body W during transport).

[0056] The laser irradiation unit 106 irradiates the continuous body W with laser L at the cutting position 28. Therefore, the laser L irradiates the portion of the continuous body W that has been tensioned by the tension-applying mechanism 104. As a result, the continuous body W is cut and monolithically divided into multiple partitions Wa. When the partition cutting device 100 constitutes the partition cutting drum 12, the first partition continuous body S1 and the second partition continuous body S2 included in the continuous laminate 26 are cut and monolithically divided into multiple unit laminates.

[0057] The laser irradiation unit 106 has a known laser oscillator. The type of laser oscillator can be appropriately selected according to the material of the continuous body W to be cut. In this embodiment, the continuous body W to be cut has a substrate layer and a heat-resistant layer covering the surface of the substrate layer. The substrate layer is made of resins such as polyethylene (PE), polyethylene terephthalate (PET), and polypropylene (PP). The heat-resistant layer has a heat resistance that is at least higher than that of the substrate layer, and is made of ceramics such as boehmite, magnesium oxide, and barium sulfate, or heat-resistant resins such as aromatic polyamides. A CO2 laser oscillator can be exemplified as a laser oscillator suitable for cutting such a continuous body W. In addition, the continuous body may not have a heat-resistant layer. Furthermore, the laser oscillator is not limited to a CO2 laser oscillator.

[0058] When the continuous body W is irradiated with laser L, it is heated and softened. Consequently, at the cutting position 28, the fracture strength of the continuous body W decreases below the tension applied by the tension applying mechanism 104, and the continuous body W is cut. That is, the continuous body W is cut by the synergistic effect of laser L and tension. Therefore, the energy density required to cut the continuous body W can be reduced. Thus, for example, when the scanning speed of laser L is increased while maintaining the same output intensity, the continuous body W can be cut by applying tension even when it cannot be cut without tension. The magnitude of the tension applied by the tension applying mechanism 104 can be appropriately set based on the designer's experiments and simulations, according to the output intensity of laser L, scanning speed, etc.

[0059] As described above, the separator cutting device 100 of this embodiment includes: a conveying section 102 for conveying a continuous body W of separators Wa for conveying batteries; a tension applying mechanism 104 for applying tension to at least a portion of the continuous body W along the conveying direction A of the continuous body W; and a laser irradiation section for irradiating a portion of the continuous body W that has been tensioned by the tension applying mechanism 104 with a laser L to monolithize it into a plurality of separators Wa.

[0060] Increasing the scanning speed of laser L to shorten the cutting time of the continuum W reduces the energy density imparted to the continuum W. Compensating for this by increasing the output intensity of laser L could increase the cost of battery manufacturing equipment. Furthermore, since the resin substrate layer is easily thermally modified, increasing the output intensity of laser L could have drawbacks. For example, thermal modification of the separator Wa could prevent the electrode reaction from occurring properly. Additionally, some batteries have a safety function that stops the electrode reaction due to thermal modification of the separator Wa when overheating occurs, but this safety function might not function correctly. Moreover, the hardening of the separator Wa due to thermal modification could damage surrounding separators Wa.

[0061] In contrast, in the separator cutting apparatus 100 of this embodiment, tension is applied to the continuous body W by the tension applying mechanism 104 during cutting. This allows the separator Wa to be cut off from the continuous body W along the portion softened by laser L irradiation. Therefore, since the continuous body W can be cut with a lower energy density, the scanning speed of laser L can be increased. Thus, according to the separator cutting apparatus 100 of this embodiment, the cutting time of the continuous body W can be shortened without depending on the increase in the output intensity of laser L. As a result, battery production costs can be reduced, and production preparation time and production volume can be increased.

[0062] Furthermore, the conveying unit 102 of this embodiment includes: a plurality of holding heads 108 holding the continuous body W; and a drum 110 in which the plurality of holding heads 108 are arranged and rotated to move each holding head 108 toward a cutting position 28 opposite to the laser irradiation unit 106. The tension applying mechanism 104 applies tension to the continuous body W by increasing the interval G1 between two adjacent holding heads 108. In addition, the tension applying mechanism 104 includes: a plurality of motors 114 that move each holding head 108 independently of the movement caused by the rotation of the drum 110; and a control unit 116 that controls the driving of each motor 114. Furthermore, the control unit 116 controls the driving of the motors 114 by increasing the interval between two adjacent holding heads 108. As a result, the desired tension can be applied to the portion of the continuous body W irradiated by the laser L more reliably and simply.

[0063] The embodiments of this disclosure have been described in detail above. The above embodiments are merely specific examples of implementing this disclosure. The content of the embodiments does not limit the technical scope of this disclosure; various design changes, such as alterations, additions, and deletions of constituent elements, can be made without departing from the spirit of this disclosure as defined in the claims. New embodiments with applied design changes combine the effects of the combined embodiments and their variations. In the above embodiments, the content that allows such design changes is emphasized by expressions such as "in this embodiment" or "in this embodiment," but design changes are also permitted for content without such expressions. Any combination of the above constituent elements is also valid as a solution of this disclosure. The shading lines in the cross-section annotations of the drawings do not limit the material of the objects shaded.

[0064] The invention described above can also be identified by the items described below.

[0065] [Project 1]

[0066] A method for cutting a partition includes the following steps:

[0067] A continuous body (W) of separators (Wa) used for transporting batteries;

[0068] Tension is applied to at least a portion of the continuous (W) along the conveying direction (A) of the continuous (W); and

[0069] A portion of a continuum (W) under tension is irradiated with a laser (L) and monolithized into multiple partitions (Wa).

[0070] [Industrial Availability]

[0071] This disclosure can be used for partition cutting devices and partition cutting methods.

[0072] [Explanation of reference numerals in the attached figures]

[0073] 100. Partition cutting device; 102. Conveying unit; 104. Tension applying mechanism; 106. Laser irradiation unit; 108. Holding head; 110. Drum; 114. Motor; 116. Control unit.

Claims

1. A partition cutting device, comprising: A conveying section for a continuous body of separators used to transport batteries. A tension-applying mechanism that applies tension to at least a portion of the continuous body along the conveying direction of the continuous body, and A laser irradiation section is monolithically divided into multiple partitions by irradiating a portion of the continuous body that has been tensioned by the tension-imposing mechanism with a laser. The conveying section includes: a plurality of holding heads that hold the continuous body, and a drum in which the plurality of holding heads are arranged and rotated to move each holding head toward a cutting position opposite to the laser irradiation section; The tension-applying mechanism applies tension to the continuum by increasing the spacing between two adjacent holding heads; The plurality of holding heads, arranged at intervals, hold the continuum while moving toward the cutting position; The tension-applying mechanism applies tension to the portion of the continuous body extending at the cut position by causing the holding head that reaches the cut position to accelerate past the cut position compared to the subsequent holding head, thereby widening the interval between two holding heads arranged at the cut position compared to the interval between two holding heads arranged in other areas.

2. The partition cutting device as described in claim 1, The tension-applying mechanism includes: multiple motors that allow each holding head to move independently of the movement caused by the rotation of the drum, and a control unit that controls the drive of each motor; The control unit controls the drive of the motor by increasing the interval between two adjacent holding heads.

3. A method for cutting a partition, comprising the following steps: A continuous structure of separators used for transporting batteries. Tension is applied to at least a portion of the continuous body along the conveying direction of the continuous body, and The portion of the continuum under tension is irradiated with a laser to monolithize it into multiple partitions; The continuous body is transported by a transport section, which has: a plurality of holding heads that hold the continuous body, and a drum on which the plurality of holding heads are arranged and rotated to move each holding head toward the cutting position irradiated by the laser. The plurality of holding heads are arranged at intervals while holding the continuous body and moving toward the cutting position. The tension is applied by causing the holding head that reaches the cut position to accelerate past the cut position compared to the subsequent holding head, thereby widening the interval between two holding heads arranged at the cut position compared to the interval between two holding heads arranged in other areas, thus applying tension to the portion of the continuum in the conveying state that extends at the cut position.

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