Separator cutting device and separator cutting method

Abstract

A separator cutting device 100 comprises: a conveyance part 102 for conveying a continuum W of a battery separator Wa; a tension application mechanism 104 for applying tension to at least a portion of the continuum W in a continuum W conveying direction A; and a laser irradiation part 106 for irradiating, with a laser light L, the portion of the continuum W to which tension has been applied by the tension application mechanism 104 and dividing the same into a plurality of individual separators Wa.

Description

[Technical Field]

[0001] The present disclosure relates to a separator cutting device and a separator cutting method. [Background technology]

[0002] Laminated batteries have been developed for use in automobiles and the like. These batteries have a structure in which a laminated electrode body, in which multiple positive electrode plates and multiple negative electrode plates are alternately stacked with separators sandwiched between them, and an electrolyte are housed in a container. Forming the laminated electrode body may involve cutting a continuous separator into individual pieces. For example, Patent Document 1 discloses a separator cutting device that irradiates a long separator substrate (a continuous separator body) with a laser beam to separate it into rectangular separators. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-72785 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, with the spread of electric vehicles and mobile devices, battery shipments have been increasing, and improvements in battery production lead time and throughput are required. Therefore, there is a demand for shortening the cutting time of a separator continuum. One possible method for shortening the cutting time of a continuum is to increase the scanning speed of the laser beam. However, increasing the scanning speed of the laser beam reduces the energy density imparted to the cutting portion of the continuum, making cutting difficult. In response to this, it is possible to increase the output intensity of the laser beam, but this would require more expensive laser equipment, which could lead to increased costs.

[0005] The present disclosure has been made in light of these circumstances, and one of its objectives is to provide a technique for shortening the time required to cut a continuous body of separators without relying on increasing the output intensity of laser light. [Means for solving the problem]

[0006] One aspect of the present disclosure is a separator cutting device that includes a conveying unit that conveys a continuous body of battery separators, a tensioning mechanism that applies tension to at least a portion of the continuous body in the conveying direction of the continuous body, and a laser irradiation unit that irradiates the portion of the continuous body that has been tensioned by the tensioning mechanism with a laser beam to separate the continuous body into a plurality of separators.

[0007] One aspect of the present disclosure is a separator cutting method, which includes conveying a continuous body of battery separators, applying tension to at least a portion of the continuous body in the conveying direction of the continuous body, and irradiating the tensioned portion of the continuous body with laser light to separate the continuous body into a plurality of separators.

[0008] Any combination of the above components, and conversion of the expression of the present disclosure into a method, device, system, etc., are also valid aspects of the present disclosure. [Effects of the Invention]

[0009] According to the present disclosure, the time required to cut a continuous body of separators can be reduced without relying on an increase in the output intensity of the laser light. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a schematic diagram of a laminated electrode body manufacturing apparatus. [Figure 2] 1 is a schematic diagram of a portion of a separator cutting device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present disclosure will be described below with reference to preferred embodiments and drawings. The embodiments are illustrative and do not limit the present disclosure, and all features and combinations thereof described in the embodiments are not necessarily essential to the present disclosure. The same or equivalent components, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not indicate any order or importance, but are intended to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted from each drawing.

[0012] FIG. 1 is a schematic diagram of a laminated electrode body manufacturing apparatus 1. The laminated electrode body manufacturing apparatus 1 is, for example, a continuous drum type manufacturing apparatus that combines multiple drums. By using the drums to perform each process of cutting, heating, bonding, and laminating the electrode body and separators, laminated electrode bodies can be manufactured continuously at high speed. The laminated electrode body is used, for example, in a lithium ion secondary battery. Note that the structure of the laminated electrode body manufacturing apparatus 1 is not limited to the continuous drum type.

[0013] The laminated electrode body 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 separator cutting drum 12, and a lamination drum 14.

[0014] The first electrode cutting drum 2 is a drum that cuts a continuum of a plurality of first electrode plates, separates them into a plurality of first electrode plates, and transports them. In this embodiment, the first electrodes are negative electrodes. A strip-shaped first electrode continuum N, which is a continuum of a plurality of first electrode plates, is supplied to the first electrode cutting drum 2. The first electrode continuum N has a first electrode current collector and a first electrode active material layer. The first electrode active material layer is laminated on the first electrode current collector. In this embodiment, the first electrode active material layer is laminated on both sides of the first electrode current collector, but the first electrode active material layer may also be laminated on only one side of the first electrode current collector.

[0015] The first electrode current collector and the first electrode active material layer can both be made of known materials and have known structures. The first electrode current collector is made of a foil or porous body made of, for example, copper or aluminum. The first electrode active material layer is formed, for example, by applying a first electrode composite slurry containing a first electrode active material, a binder, a dispersant, etc., to the surface of the first electrode current collector, drying the coating, and rolling it. The thickness of the first electrode current collector is, for example, 3 μm to 50 μm. The thickness of the first electrode active material layer is, for example, 10 μm to 100 μm.

[0016] The first pole cutting drum 2 has multiple holding heads arranged in the circumferential direction of the drum and cutting blades that cut the first pole continuous body N. The multiple holding heads have holding surfaces that attract and hold the first pole continuous body N. The holding surfaces of each holding head face outward from the first pole cutting drum 2. The first pole continuous body N supplied to the first pole cutting drum 2 is transported by the rotation of the first pole cutting drum 2 while being attracted and held by the holding surfaces of the multiple holding heads.

[0017] Each of the multiple holding heads rotates around the central axis of the first pole cutting drum 2 and can move circumferentially around the drum independently of the other holding heads. The relative movement of each holding head is achieved by mounting a motor separate from the motor that rotates the first pole cutting drum 2 on each holding head. Independent driving of the holding heads makes it possible to adjust the cutting position of the cutting blade on the first pole continuum N and to adjust the position of the individualized first pole plates.

[0018] The first electrode cutting drum 2 suction-holds and rotates to transport the supplied first electrode continuum N, cutting the first electrode continuum N at cutting positions 16 shown schematically in FIG. 1. The first electrode continuum N is cut by cutting blades at positions between adjacent holding heads to be separated into a plurality of first electrode plates. Each of the obtained first electrode plates is transported while being suction-held by each holding head. The positions of the plurality of first electrode plates being produced are monitored by a camera or the like.

[0019] The first pole heating drum 4 is positioned close to the first pole cutting drum 2. The holding head of the first pole cutting drum 2 temporarily increases or decreases its speed until it becomes substantially the same as the linear speed of the first pole heating drum 4 just before it approaches the position close to the first pole heating drum 4. As a result, the relative speed of the holding head to the first pole heating drum 4 becomes substantially zero. When the relative speed becomes substantially zero, the holding head ejects the first pole plate that it has been adsorbing and holding toward the first pole heating drum 4.

[0020] The first electrode heating drum 4 rotates while suction-holding the first electrode plate discharged from the first electrode cutting drum 2, and preheats the first electrode plate with a built-in heater. Preheating is performed to thermally bond the separator and 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 limiting, and the first electrode plate may be heated over the entire circumferential area of ​​the first electrode heating drum 4, for example.

[0021] The second electrode cutting drum 6 is a drum that cuts a continuum of multiple second electrode plates, separates them into multiple second electrode plates, and transports them. In this embodiment, the second electrodes are positive electrodes. A strip-shaped second electrode continuum P, which is a continuum of multiple second electrode plates, is supplied to the second electrode cutting drum 6. The second electrode continuum P has a second electrode current collector and a second electrode active material layer. The second electrode active material layer is laminated on the second electrode current collector. In this embodiment, the second electrode active material layer is laminated on both sides of the second electrode current collector, but the second electrode active material layer may be laminated on only one side of the second electrode current collector.

[0022] The second electrode current collector and the second electrode active material layer can both be made of known materials and have known structures. The second electrode current collector is made of a foil or porous body made of, for example, stainless steel or aluminum. The second electrode active material layer is formed, for example, by applying a second electrode composite slurry containing a second electrode active material, a binder, a dispersant, etc., to the surface of the second electrode current collector, drying the coating, and rolling it. The thickness of the second electrode current collector is, for example, 3 μm to 50 μm. The thickness of the second electrode active material layer is, for example, 10 μm to 100 μm.

[0023] The second pole cutting drum 6 has multiple holding heads arranged in the circumferential direction of the drum and cutting blades for cutting the second pole continuous body P. The multiple holding heads have holding surfaces that attract and hold the second pole continuous body P. The holding surfaces of each holding head face outward from the second pole cutting drum 6. The second pole continuous body P supplied to the second pole cutting drum 6 is transported by the rotation of the second pole cutting drum 6 while being attracted and held by the holding surfaces of the multiple holding heads.

[0024] Each of the multiple holding heads rotates around the central axis of the second pole cutting drum 6 and can move circumferentially around the drum independently of the other holding heads. The relative movement of each holding head is achieved by mounting a motor separate from the motor that rotates the second pole cutting drum 6 on each holding head. Independent driving of the holding heads makes it possible to adjust the cutting position of the cutting blade on the second pole continuum P and adjust the position of the individual second pole plates.

[0025] The second electrode cutting drum 6 suction-holds and rotates to transport the supplied second electrode continuum P, cutting the second electrode continuum P at a cutting position 20 shown schematically in FIG. 1. The second electrode continuum P is cut by a cutting blade at a position between adjacent holding heads to be separated into a plurality of second electrode plates. Each of the obtained second electrode plates is transported while being suction-held by each holding head. The positions of the plurality of second electrode plates being produced are monitored by a camera or the like.

[0026] 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 increases or decreases its speed until it becomes substantially the same as the linear speed of the second electrode heating drum 8 just before it approaches the position close to the second electrode heating drum 8. As a result, the relative speed of the holding head with respect to the second electrode heating drum 8 becomes substantially zero. When the relative speed becomes substantially zero, the holding head ejects the second electrode plate that it has been adsorbing and holding toward the second electrode heating drum 8.

[0027] The second electrode heating drum 8 rotates while suction-holding the second electrode plate discharged from the second electrode cutting drum 6, and preheats the second electrode plate with a built-in heater. The preheating is performed to thermally bond the separator and 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 limiting, and the second electrode plate may be heated over the entire circumferential area of ​​the second electrode heating drum 8, for example.

[0028] The bonding drum 10 forms a continuous laminate 26, consisting of a plurality of continuous unit laminates. Each unit laminate is composed of a first separator, a first electrode plate, a second separator, and a second electrode plate. A strip-shaped first separator continuous body S1, consisting of a plurality of continuous first separators, and a strip-shaped second separator continuous body S2, consisting of a plurality of continuous second separators, are supplied to the bonding drum 10. A thermal adhesive layer is provided on the surface of each of the first separator continuous body S1 and the second separator continuous body S2. The thermal adhesive layer does not exhibit adhesive properties at room temperature, but exhibits adhesive properties upon heating. For example, the thermal adhesive layer is a thermoplastic layer containing a thermoplastic polymer, and exhibits adhesive properties due to the plastic deformation of the thermoplastic polymer upon heating.

[0029] The bonding drum 10 is disposed adjacent to the first electrode heating drum 4 and the second electrode heating drum 8. A plurality of 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 a plurality of 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 rotated and conveyed while being preheated by the first electrode heating drum 4, and are discharged toward the bonding drum 10 at a position where the first electrode heating drum 4 and the bonding drum 10 are close to each other. The second electrode plates are rotated and conveyed while being preheated by the second electrode heating drum 8, and are discharged toward the bonding drum 10 at a position where the second electrode heating drum 8 and the bonding drum 10 are close to each other.

[0030] The supply positions of the first separator web S1, first electrode plate, second separator web S2, and second electrode plate to the bonding drum 10 are arranged in the listed order from the upstream side in the rotation direction of the bonding drum 10. Therefore, first, the first separator web S1 is supplied to the bonding drum 10 at a predetermined position. The first separator web S1 is adsorbed and held by the bonding drum 10 and rotated and conveyed. Next, a first electrode plate is supplied from the first electrode heating drum 4 to the bonding drum 10 downstream of the supply position of the first separator web S1 and placed on the first separator web S1. The multiple first electrode plates are arranged on the first separator web S1 at predetermined intervals in the conveyance direction of the first separator web S1.

[0031] Next, downstream of the supply position of the first electrode plates, a second separator continuous web S2 is supplied to the bonding drum 10 and placed on top of the multiple first electrode plates. Next, downstream of the supply position of the second separator continuous web S2, the first separator continuous web S1, the multiple first electrode plates, and the second separator continuous web S2 are pressed by a thermocompression roller 24 to bond them together. Next, downstream of the compression position of the thermocompression 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 separator continuous web S2. The multiple second electrode plates are arranged on the second separator continuous web S2 at predetermined intervals in the conveyance direction of the second separator continuous web S2. Furthermore, the pressing force of the second electrode heating drum 8 bonds the multiple second electrode plates to the second separator continuous web S2.

[0032] Through the above steps, the first separator continuum S1, multiple first electrode plates, second separator continuum S2, and multiple second electrode plates are stacked and bonded in this order to form a continuous laminate 26. The continuous laminate 26 has a structure in which unit laminate bodies each consisting of a first separator, a first electrode plate, a second separator, and a second electrode plate are connected by the first separator continuum S1 and the second separator continuum S2. The continuous laminate 26 is transported from the bonding drum 10 to the separator cutting drum 12. Note that by not supplying second electrode plates from the second electrode cutting drum 6, a three-layer unit laminate body not including second electrode plates may be produced for each certain number of units. The electrode plates not supplied may also be first electrode plates.

[0033] The separator cutting drum 12 is a drum that cuts the first separator continuum S1 and the second separator continuum S2 of the continuous laminate 26 into a plurality of unit laminate bodies. The separator cutting drum 12 adsorbs and holds the continuous laminate 26 with a plurality of holding heads arranged in the circumferential direction of the drum, and transports the continuous laminate 26 by rotating the drum. The separator cutting drum 12 cuts the continuous laminate 26 at a cutting position 28, which is schematically shown in FIG. 1. The continuous laminate 26 is cut at a position between adjacent holding heads and separated into a plurality of unit laminate bodies. At this time, the first separator continuum S1 and the second separator continuum S2 of the continuous laminate 26 are cut between adjacent electrode plates in the transport direction of the continuous laminate 26.

[0034] The obtained unit laminate bodies are conveyed while being sucked and held by the respective holding heads. The holding heads discharge the unit laminate bodies that they have sucked and held toward the stacking drum 14. The positions of the multiple unit laminate bodies that are produced are monitored by a camera or the like. The structure of the separator cutting drum 12 will be described in detail later.

[0035] The stacking drum 14 is a drum that stacks a plurality of unit laminate bodies on the stacking stage 30 to form a laminated electrode body. The stacking drum 14 has a plurality of stacking heads arranged in the circumferential direction of the drum. Each stacking head has a holding surface that attracts and holds the unit laminate bodies. The holding surface of each stacking head faces outward from the stacking drum 14. The multiple stacking heads each rotate around the central axis of the stacking drum 14 and move sequentially to stacking positions that face the stacking stage 30. When a stacking head reaches a stacking position, it ejects the unit laminate bodies it is holding onto the stacking stage 30.

[0036] The stacking stage 30 is disposed directly below the stacking drum 14. Unit laminate bodies discharged from each stacking head of the stacking drum 14 are sequentially stacked on the stacking stage 30. This forms a laminated electrode body. The stacking stage 30 is drivable in the X-axis and Y-axis directions, which are orthogonal to each other. The stacking stage 30 is also capable of adjusting the tilt angle on the X-Y plane. This allows the positions in the X-axis and Y-axis directions and the tilt angle of the unit laminate bodies discharged from the stacking drum 14 to be adjusted relative to the unit laminate bodies already stacked on the stacking stage 30.

[0037] The separator cutting drum 12 is configured by a separator cutting device 100 according to this embodiment. FIG. 2 is a schematic diagram of a portion of the separator cutting device 100 according to this embodiment. Note that FIG. 2 shows a perspective view of the continuum W. The separator cutting device 100 includes a conveying unit 102, a tension applying mechanism 104, and a laser irradiation unit 106.

[0038] The conveying section 102 conveys a continuous body W of separators Wa for batteries. 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. The separators Wa correspond to the first separator and the second separator in the unit laminate. Note that the continuous body W may be a single first separator continuous body S1 or a single second separator continuous body S2.

[0039] The conveying unit 102 of this embodiment has a plurality of holding heads 108 and a drum unit 110. The plurality of holding heads 108 hold the continuum W. Each holding head 108 has a holding surface 112 that holds the continuum W. For example, the holding surface 112 has a suction mechanism that sucks in atmospheric gas such as air, and can suction and hold the continuum W.

[0040] The drum unit 110 is disk-shaped (see FIG. 1), and multiple holding heads 108 are arranged at approximately equal intervals on the circumference. Note that FIG. 2 shows the drum unit 110 as a schematic flat shape. When arranged on the drum unit 110, the holding surface 112 of each holding head 108 faces outward in the radial direction of the drum unit 110. A drive mechanism (not shown), such as a motor, is connected to the central axis of the drum unit 110, and the drum unit 110 can rotate around the central axis.

[0041] The drum unit 110 rotates to advance each holding head 108 toward and pass through the cutting position 28. This allows the continuous body W to be continuously transported to the cutting position 28. The cutting position 28 is a position where the drum unit 110 and the laser irradiation unit 106 (more precisely, the emission port that emits the laser light L toward the drum unit 110) face each other.

[0042] The tension applying mechanism 104 applies tension to at least a portion of the continuum W in the conveying direction A of the continuum W. The tension applying mechanism 104 of the present embodiment applies tension to the continuum W in a conveying state by displacing two adjacent holding heads 108 relative to each other in the circumferential direction of the drum unit 110 and widening the gap between the two holding heads 108. For example, the tension applying mechanism 104 widens the gap G1 between the two holding heads 108 arranged on either side of the cutting position 28 to be larger than the gap G2 between the two holding heads 108 arranged in another region. This applies tension to the portion of the continuum W that is located at the cutting position 28.

[0043] To achieve this tension application, the tension application mechanism 104 has multiple motors 114 provided in each holding head 108 and a control unit 116 that controls the drive of each motor 114. A known stepping motor or the like can be used as the motor 114. Each holding head 108 is connected to the drum unit 110 via the motor 114. Each motor 114 moves each holding head 108 independently of the movement caused by the rotation of the drum unit 110. Therefore, each holding head 108 rotates around the central axis of the drum unit 110 as the drum unit 110 rotates, and can move in the circumferential direction of the drum unit 110 independently of the other holding heads 108 as the motors 114 drive them.

[0044] The control unit 116 controls the driving of the motors 114 provided on the corresponding holding heads 108 so as to widen the gap G1 between the two adjacent holding heads 108 across the cutting position 28. In FIG. 2, the control unit 116 is depicted as a functional block. This functional block is realized as a hardware configuration by elements and circuits such as a computer CPU and memory, and as a software configuration by a computer program or the like. Those skilled in the art will understand that these functional blocks can be realized in various ways by combining hardware and software. The control unit 116 can control the driving of each motor 114 based on a preset operating program.

[0045] For example, the multiple holding heads 108 are arranged at intervals G2 and suction-hold the continuum W. Then, the holding heads 108 that reach the cutting position 28 pass through the cutting position 28 while accelerating more than the subsequent holding heads 108. As a result, the interval G1 between two holding heads 108 lined up on either side of the cutting position 28 becomes wider than the interval G2 between two holding heads 108 lined up in another region. As a result, tension is applied to the portion of the continuum W that is being conveyed and extends to the cutting position 28.

[0046] The distance between two adjacent holding heads 108 can also be increased by a cam mechanism including a cam groove that does not follow the rotation of the drum unit 110 and a protrusion that is provided on each holding head 108 and engages with the cam groove. Alternatively, the tensioning mechanism 104 may apply tension to the continuum W before it is supplied to the conveying unit 102, and the conveying unit 102 may convey the continuum W while maintaining the tension. In this case, the tensioning mechanism 104 may be configured, for example, by a combination of nip rolls, suction rolls, dancer rolls, etc., that are provided in a supply line that supplies the continuum W to the conveying unit 102.

[0047] Furthermore, the conveying unit 102 is not limited to a roll type that conveys the continuum W in the circumferential direction of the drum unit 110, but may be a stage type that conveys the continuum W in, for example, a horizontal direction. In this case, the tension applying mechanism 104 may be configured by a combination of nip rolls, suction rolls, dancer rolls, etc., that are provided in the conveying unit 102.

[0048] Furthermore, the tension applying mechanism 104 may apply tension to portions of the continuum W other than those extending to the cutting position 28. For example, tension may be applied to the entire continuum W by an unwinding device located at the upstream end of the conveying line of the continuum W and a winding device located at the downstream end. However, as in the present embodiment, applying tension locally in addition to the tension applied to the continuum W as it is conveyed is more preferable because it makes it possible to more reliably and more easily apply the desired tension to the portion of the continuum W extending to the cutting position 28.

[0049] The magnitude of the tension applied per unit area of ​​the cross section perpendicular to the conveying direction A of the continuum W is preferably 1.9 N / mm 2 More preferably, it is 2.9 N / mm 2 More preferably, it is 3.8 N / mm 2 More preferably, it is 4.8 N / mm 2 That's it. Tension is 1.9N / mm 2By doing so, when the irradiation conditions of the laser light L are, for example, an output of 100 W and a scanning speed of 5000 mm / s, it is possible to more easily cut the continuum W. Note that the present inventors have confirmed that when tension is not applied to the continuum W under the same irradiation conditions (excluding tension applied to the continuum W during transportation), the continuum W cannot be cut.

[0050] The laser irradiation unit 106 irradiates the continuum W with laser light L at the cutting position 28. Therefore, the laser light L is irradiated to the portion of the continuum W to which tension is applied by the tension applying mechanism 104. As a result, the continuum W is cut and separated into a plurality of separators Wa. When the separator cutting device 100 forms the separator cutting drum 12, the first separator continuum S1 and the second separator continuum S2 included in the continuous stack 26 are cut and separated into a plurality of unit stack bodies.

[0051] The laser irradiation unit 106 has a known laser oscillator. The type of laser oscillator can be appropriately selected depending on the material of the continuum W to be cut. In this embodiment, the continuum W to be cut has a base layer and a heat-resistant layer covering the surface of the base layer. The base layer is made of a resin such as polyethylene (PE), polyethylene terephthalate (PET), or polypropylene (PP). The heat-resistant layer has higher heat resistance than at least the base layer, and is made of, for example, ceramics such as boehmite, magnesium oxide, or barium sulfate, or a heat-resistant resin such as aramid. An example of a laser oscillator suitable for cutting such a continuum W is a CO2 laser oscillator. Note that the continuum does not need to have a heat-resistant layer. Furthermore, the laser oscillator is not limited to a CO2 laser oscillator.

[0052] When the laser beam L is irradiated onto the continuum W, the continuum W is heated and softened. As a result, at the cutting position 28, the breaking strength of the continuum W decreases below the tension applied by the tension applying mechanism 104, and the continuum W is cut. In other words, the continuum W is cut by the synergistic effect of the laser beam L and the tension. This makes it possible to reduce the energy density required to cut the continuum W. Therefore, for example, when the scanning speed of the laser beam L is increased while keeping the output intensity of the laser beam L the same, even if the continuum W cannot be cut without applying tension, the continuum W can be cut by applying tension. The magnitude of the tension applied by the tension applying mechanism 104 can be appropriately set by a designer based on experiments and simulations in accordance with the output intensity, scanning speed, etc. of the laser beam L.

[0053] As described above, the separator cutting device 100 according to this embodiment includes a conveying section 102 that conveys a continuous body W of battery separators Wa, a tensioning mechanism 104 that applies tension to at least a portion of the continuous body W in the 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 tension has been applied by the tensioning mechanism 104 with laser light L to separate the continuous body W into a plurality of separators Wa.

[0054] Increasing the scanning speed of the laser light L to shorten the cutting time of the continuum W reduces the energy density imparted to the continuum W. Attempting to compensate for this by increasing the output intensity of the laser light L could lead to increased costs for battery manufacturing equipment. Furthermore, because resin substrate layers are susceptible to thermal denaturation, increasing the output intensity of the laser light L could have adverse effects. For example, thermal denaturation of the separator Wa could prevent the electrode reaction from occurring normally. Some batteries are equipped with a safety feature that thermally denatures the separator Wa and stops the electrode reaction when excessive heat is generated, but this safety feature could malfunction. Furthermore, the separator Wa hardened by thermal denaturation could damage surrounding separators Wa.

[0055] In contrast, in the separator cutting device 100 of the present embodiment, tension is applied to the continuum W by the tension applying mechanism 104 when cutting the continuum W. This allows the separator Wa to be cut from the continuum W along the portion softened by irradiation with the laser light L. This makes it possible to cut the continuum W at a lower energy density, allowing the scanning speed of the laser light L to be increased. Therefore, the separator cutting device 100 of the present embodiment can shorten the cutting time of the continuum W without relying on an increase in the output intensity of the laser light L. As a result, it is possible to reduce battery production costs while improving production lead time and throughput.

[0056] The conveying unit 102 of this embodiment also includes a plurality of holding heads 108 that hold the continuum W, and a drum unit 110 on which the plurality of holding heads 108 are arranged and which rotates to advance each holding head 108 toward the cutting position 28 facing the laser irradiation unit 106. The tensioning mechanism 104 applies tension to the continuum W by widening the gap G1 between two adjacent holding heads 108. The tensioning mechanism 104 also includes a plurality of motors 114 that move each holding head 108 independently of the movement caused by the rotation of the drum unit 110, and a control unit 116 that controls the drive of each motor 114. The control unit 116 then controls the drive of the motors 114 so as to widen the gap between two adjacent holding heads 108. This makes it possible to more reliably and more easily apply the desired tension to the portion of the continuum W that is irradiated with the laser light L.

[0057] The above describes the embodiments of the present disclosure in detail. The above-described embodiments merely illustrate specific examples of implementing the present disclosure. The content of the embodiments does not limit the technical scope of the present disclosure, and many design modifications, such as changing, adding, or deleting components, are possible within the scope of the concept of the present disclosure defined in the claims. A new embodiment with design modifications will combine the effects of the combined embodiments and modifications. In the above-described embodiments, the content in which such design modifications are possible is emphasized by using notations such as "in this embodiment" or "in this embodiment," but design modifications are also permitted even in content without such notation. Any combination of the above components is also valid as an aspect of the present disclosure. Hatching in cross sections in the drawings does not limit the material of the hatched object.

[0058] The invention according to the above-described embodiment may be specified by the following items. [Item 1] Conveying a continuous body (W) of battery separators (Wa), applying tension to at least a portion of the continuum (W) in the conveying direction (A) of the continuum (W); and irradiating the tensioned portion of the continuum (W) with laser light (L) to separate it into a plurality of separators (Wa). Separator cutting method. [Industrial Applicability]

[0059] The present disclosure can be used in a separator cutting device and a separator cutting method. [Explanation of symbols]

[0060] 100 separator cutting device, 102 conveying section, 104 tensioning mechanism, 106 laser irradiation section, 108 holding head, 110 drum section, 114 motor, 116 control section.

Claims

1. a conveying unit that conveys a continuous body of battery separators; a tension applying mechanism that applies tension to at least a portion of the continuous web in a transport direction of the continuous web; a laser irradiation unit that irradiates a portion of the continuum to which tension has been applied by the tension applying mechanism with laser light to separate the continuum into a plurality of separators, the conveying unit includes a plurality of holding heads that hold the continuous body, and a drum unit on which the plurality of holding heads are arranged and that rotates to advance each holding head toward a cutting position facing the laser irradiation unit; the tension applying mechanism applies tension to the continuum by widening the gap between two adjacent holding heads; the plurality of holding heads move toward the cutting position while holding the continuous body in a spaced-apart arrangement; the tension applying mechanism causes the holding head that has reached the cutting position to pass through the cutting position while accelerating more than the subsequent holding head, thereby widening the gap between the two holding heads aligned on either side of the cutting position to be greater than the gap between the two holding heads aligned in other regions, and applying tension to a portion of the continuum that is in a conveying state and extends to the cutting position. Separator cutting device.

2. the tension applying mechanism includes a plurality of motors that move each holding head independently of the movement caused by the rotation of the drum unit, and a control unit that controls the driving of each motor, the control unit controls the driving of the motor so as to widen the interval between two adjacent holding heads. The separator cutting device according to claim 1 .

3. Conveying a continuous sheet of battery separators; applying tension to at least a portion of the continuous body in a conveying direction of the continuous body; irradiating the tensioned portion of the continuum with laser light to separate it into a plurality of separators; the conveyance of the continuous body is performed by a conveyance unit having a plurality of holding heads that hold the continuous body, and a drum unit on which the plurality of holding heads are arranged and that rotates to advance each holding head toward a cutting position where the laser light is irradiated, the conveyance unit advancing the plurality of holding heads toward the cutting position while holding the continuous body in a state where the plurality of holding heads are arranged at intervals; The application of tension includes passing the cutting position while accelerating the holding head that has reached the cutting position more rapidly than the subsequent holding head, thereby widening the gap between the two holding heads aligned on either side of the cutting position to be larger than the gap between the two holding heads aligned in other regions, and applying tension to a portion of the continuum that is in a conveying state and extends to the cutting position. Separator cutting method.

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