Easy slitting or cutting of flexible substrates containing reactive metal or alloy films

Abstract

Systems and methods for cutting substrates comprising metals, e.g., lithium metals, which can be used in energy storage devices. In one aspect, a system for slitting a flexible support layer stack is provided. The system includes a laser source configured to generate a laser beam, and the laser beam is directed toward a first surface of the flexible support layer stack. The system further includes an optical scanner configured to direct the laser beam toward the first surface of the flexible support layer stack. The system further includes a pickup roller positioned opposite the laser beam, the pickup roller is positioned to contact a second surface of the flexible support layer stack, and the second surface is opposite to the first surface. The system further includes a cutting assembly positioned downstream of the laser beam.

Description

Technology Field

[0001] The present disclosure relates to systems and methods for cutting substrates comprising metals that can generally be used in energy storage devices, e.g., lithium metals. Background Technology

[0002] Rechargeable electrochemical energy storage systems are becoming increasingly important in many areas of daily life. High-capacity energy storage devices, such as lithium-ion (Li-ion) batteries and capacitors, are used in a growing number of applications, including portable electronics, medical, transportation, grid-connected large-scale energy storage, renewable energy storage, and uninterruptible power supplies (UPS). In each of these applications, charge / discharge times and capacity are fundamental parameters of energy storage devices. Additionally, the size, weight, and / or cost of these energy storage devices are also fundamental parameters. Furthermore, low internal resistance is essential for high performance. The lower the resistance, the fewer limitations the energy storage device faces in delivering electrical energy. For example, in the case of batteries, internal resistance affects performance by reducing the battery's ability to deliver high currents, as well as the total amount of useful energy stored by the battery.

[0003] One method for manufacturing energy storage devices is roll-to-roll processing. An effective roll-to-roll deposition process not only provides high deposition rates but also provides a flat film surface that is free of small-scale roughness, contains minimal defects, and is, for example, free of large-scale topography. In addition, an effective roll-to-roll deposition process also provides consistent deposition results or "repeatability."

[0004] Thin-film lithium energy storage devices typically utilize a lithium deposition process in which a lithium thin film is deposited on or over a substrate or web before being laminated with an anode. Roll-to-roll processing often involves a specific roll width to ensure economic viability, even if the targeted roll width is smaller. Lithium-coated rolls can be cut to achieve the target roll width.

[0005] Therefore, there is a need for improved devices and methods for cutting substrates containing lithium thin films for energy storage devices.

[0006] The present disclosure relates to systems and methods for cutting substrates comprising metals that can generally be used in energy storage devices, e.g., lithium metals.

[0007] In one aspect, a system for slitting a flexible support layer stack is provided. The system includes a laser source configured to generate a laser beam, and the laser beam is directed toward a first surface of the flexible support layer stack. The system further includes an optical scanner configured to direct the laser beam toward the first surface of the flexible support layer stack. The system further includes a pickup roller positioned opposite the laser beam, the pickup roller is positioned to contact a second surface of the flexible support layer stack, and the second surface is opposite to the first surface. The system further includes a cutting assembly positioned downstream of the laser beam.

[0008] The embodiments may include one or more of the following. The laser source is an infrared laser source. The flexible support layer stack has an alkali metal film formed on a first surface. The flexible support layer stack comprises a polymer material selected from polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), poly(methyl methacrylate) (PMMA), cellulose triacetate (TAC), polypropylene (PP), polyethylene (PE), polycarbonate (PC), multilayers thereof, or combinations thereof. The cutting assembly comprises a rotary blade. The cutting assembly further comprises a blade stage. The cutting assembly comprises a second optical scanner configured to direct a second laser beam toward the flexible support layer stack. The system further includes a feed roller for feeding a stack of flexible support layers and a take-up roller for collecting the cut stacks of flexible support layers. The pick-up roller comprises stainless steel.

[0009] In another aspect, a slitting device is provided. The slitting device includes a laser unit. The laser unit includes an optical assembly, a laser source coupled to the optical assembly, and a controller coupled to the optical assembly. The slitting device further includes a blade assembly positioned downstream of the laser unit, and a pickup roller positioned upstream of the blade assembly and opposite to the optical assembly.

[0010] The embodiments may include one or more of the following. The laser source is a solid-state laser configured to generate a continuous laser beam. The laser source is a solid-state laser configured to generate a pulsed laser beam. The blade assembly includes a rotary blade. The pickup roller includes stainless steel.

[0011] In another aspect, a method for slitting a coated substrate is provided. The method comprises: supplying a coated substrate comprising at least one coating layer and a substrate layer to a laser unit; exposing a blade cutting area on the coated substrate by activating a section of at least one coating layer from the substrate layer of the coated substrate; removing the activated section of at least one coating layer; subsequently, supplying the coated substrate to a blade assembly; and slitting the coated substrate within the blade cutting area using the blade assembly.

[0012] Embodiments may include one or more of the following. A laser unit includes an optical assembly, a laser source coupled to the optical assembly, an optical bench positioned opposite the optical assembly, and a controller coupled to the optical assembly. A coating layer comprises lithium. A substrate layer comprises a flexible substrate further comprising polyethylene terephthalate, polyimide, polyphenylene sulfide, alloys thereof, or combinations thereof. A substrate layer comprises a flexible conductive substrate further comprising copper, nickel, aluminum, zinc, cobalt, tin, silicon, manganese, magnesium, alloys thereof, or combinations thereof. A blade cutting area is at least one longitudinal section of a coated substrate configured to produce at least two slit-coated substrates.

[0013] In another aspect, instructions are stored on a non-transient computer-readable medium, and when the instructions are executed by a processor, the processor causes the above device and / or method to perform operations. Brief explanation of the drawing

[0014] In a manner that the features mentioned above of the present disclosure can be understood in detail, a more specific description of the aspects briefly summarized above may be made with reference to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only ordinary embodiments of the present disclosure and should not be construed as limiting the scope of the present disclosure, as the present disclosure may allow for other equally valid embodiments.

[0015] FIG. 1a illustrates a schematic diagram of an exemplary system for cutting or slitting metals according to one or more embodiments of the present disclosure.

[0016] FIG. 1b illustrates a schematic diagram of another exemplary system for cutting or slitting metals according to one or more embodiments of the present disclosure.

[0017] FIG. 2 illustrates a plan view of a flexible support layer stack according to one or more embodiments of the present disclosure.

[0018] FIG. 3a illustrates a side cross-sectional view of a flexible support layer stack taken along line 3A-3A of FIG. 2 according to one or more embodiments of the present disclosure.

[0019] FIG. 3b illustrates a side cross-sectional view of a flexible support layer stack taken along line 3B-3B of FIG. 2 according to one or more embodiments of the present disclosure.

[0020] FIG. 3c illustrates a side cross-sectional view of a flexible support layer stack taken along line 3C-3C of FIG. 2 according to one or more embodiments of the present disclosure.

[0021] FIG. 3d illustrates a cross-sectional view of a flexible support layer stack taken along line 3D-3D of FIG. 2 according to one or more embodiments of the present disclosure.

[0022] For ease of understanding, the same reference numbers have been used where possible to designate identical elements common to the drawings. It is considered that the elements and features of one embodiment may be advantageously incorporated into other embodiments without further mention. Specific details for implementing the invention

[0023] The present disclosure relates to systems and methods for cutting substrates, including metals that can generally be used in energy storage devices, e.g., lithium metals.

[0024] Soft metals, such as lithium metal, can function as electrode materials in electrochemical cells and batteries. Bulk lithium can be commercially purchased as a solid suspension in oil or as a foil. It can also be deposited onto a substrate using various techniques such as vapor deposition, vacuum deposition, or molecular beam epitaxy. To meet the dimensions required for specific electrochemical applications, bulk lithium may be cut.

[0025] However, cutting metals such as lithium metal can present several challenges. For example, because lithium metal is soft and malleable, it can become sticky and adhere to cutting mechanisms (e.g., knives, blades, dies) when cut. This can present difficulties when cutting multiple pieces of lithium metal in succession using cutting mechanisms, as cleaning the tools between cuts can delay the electrode preparation process and dull the tools. Cutting lithium metal can also generate excessive waste, as each cut can cause lithium metal to accumulate on the cutting tools, rendering the metal unusable for battery manufacturing. Certain existing lithium metal cutting systems attempt to circumvent this problem by positioning the lithium metal between interleaves to prevent direct contact with the cutting tools. However, even in these existing systems, lithium can still undesirably adhere to interleaf materials, making subsequent removal of lithium from the interleaf materials difficult. Other existing lithium metal cutting systems utilize ultrasonic cutting techniques. However, in mass production, periodic maintenance is commonly required to remove particle debris accumulation on the blade, making it difficult to slit long webs without replacing the blade.

[0026] Systems and methods for slitting and cutting substrates are provided in one or more embodiments that may be combined with other embodiments, by first removing a reactive metal or alloy film from the substrate to be cut by a laser lift-off process. The laser lift-off process creates cutting lanes free of the reactive metal or alloy film. Then, blades can cut the substrate along the cutting lanes, which removes or reduces the accumulation of the reactive metal or alloy film on the blades. This removal or reduction of the accumulation of the reactive metal or alloy film on the blades increases the cutting blade life, which increases the time between maintenance cycles. Compared to cutting the reactive metal or alloy directly with the blades, cutting the substrate directly rather than cutting the reactive metal or alloy directly provides a cleaner cut of the substrate. A cleaner cut reduces the amount of reactive metal or alloy film that may adhere to the blades after cutting. Additionally, cleaner cuts as provided by the described systems and methods can allow for a number of repeated continuous cuts while reducing the amount of metal waste generated compared to the blades of currently available systems that cut metal directly. Furthermore, the edges of the metal can be smoother and less jagged than metals cut using conventional systems, which can reduce tearing and / or damage to other components of the electrochemical cell (e.g., polymer layers, battery separators).

[0027] In one or more embodiments that may be combined with other embodiments, systems and methods for patterned removal of lithium from a flexible support layer using a laser are provided. Patterned removal of lithium creates cutting lanes on the flexible support layer that are lithium-free or substantially free of lithium, thereby enabling a cutting blade to cut the flexible support layer along the cutting lanes without lithium accumulation on the cutting blade. In one or more embodiments, an IR fiber laser is used to activate a flexible support layer-lithium interface, e.g., a PET-lithium interface, from the side of the flexible support layer. Lithium at the activated flexible support layer-lithium interface may be subsequently removed using a pickup roller and / or a sacrificial film, e.g., a plastic film, to expose the flexible support layer placed underneath to create cutting lanes for the blade.

[0028] In one or more embodiments that may be combined with other embodiments, the described laser lift-off process or laser activation process may be integrated into a roll-to-roll tool and used in a roll-to-roll process. The laser activation process enables the transfer of patterned lithium from a plastic substrate to a pick-up roller or a sacrificial film, for example, a plastic film, by exposing an interface between a lithium metal layer and a flexible support layer, for example, a Li-PET interface, to a laser that induces lithium transfer at the interface. This interface between the lithium metal layer and the flexible support layer may also include a release layer as described.

[0029] In one or more embodiments that can be combined with other embodiments, the laser activation process enables the patterning of a flexible support layer stack (e.g., a flexible support layer and a lithium metal layer). For example, lithium can be patterned to match the pattern of the anode material in a pre-lithiation process such as lane coating or skip coating, and can also be patterned directly onto a current collector. Any suitable pattern, e.g., a square, a triangle, a circle, etc., can be achieved.

[0030] In one or more embodiments that can be combined with other embodiments, the laser activation process may use a laser source to generate an interfacial reaction between the lithium metal layer and a flexible support layer, e.g., PET, a release layer, an interface layer, or both the release layer and the interface layer, in order to enable subsequent removal of the lithium metal layer at the activated interface.

[0031] In one or more embodiments that may be combined with other embodiments, an IR fiber laser is used for laser activation and lift-off from a PET substrate having a lithium layer, e.g., a 20 μm lithium layer and a silicon release layer. In one example, the IR fiber laser is a 1064-nm laser having a pulse width of 5 to 500 nanoseconds, e.g., a 30 nanosecond pulse width, a Gaussian profile, a spot size of ~150 μm, a scan speed of 2 m / sec, and a line distance of 70 μm to generate a wobble pattern or a hatch pattern. The wobble pattern can be used for narrow lane cleaning, and the hatch pattern can be used for wide lane cleaning.

[0032] In one or more embodiments that may be combined with other embodiments, a flexible support layer stack is provided. The flexible support layer stack may comprise a plastic-containing substrate, for example, a polyethylene terephthalate (PET) substrate. The flexible support layer stack may further comprise a release layer formed on the flexible support layer stack, for example, silicon or other deposited release layers. An alkali metal-containing layer, for example, a lithium metal layer, is formed on the flexible support layer stack. In embodiments where no release layer is present, the lithium metal layer may be formed directly on the plastic-containing substrate. In embodiments where a release layer is present, the lithium metal layer may be formed directly on the release layer. The flexible support layer with the lithium metal layer formed on top is exposed to a laser activation process. In one or more embodiments, during the laser activation process, a laser is directed through the flexible support layer to activate the interface between the lithium metal layer and the flexible support layer, for example, a Li-PET interface. A laser can be directed through the back side of the flexible support layer stack, for example, from the plastic-containing substrate or PET side. Exposure to the laser can induce a lithium removal process that creates a void volume between the lithium metal layer and the flexible support layer. This void volume can facilitate the subsequent separation of the lithium metal layer from the flexible support layer while the lithium metal layer is removed from the flexible support layer stack by a pickup roller to create cutting lanes. Additionally, precise laser beam position control enables the selective removal of lithium metal to form lithium metal layers of various shapes on the flexible support layer. Furthermore, exposure to the laser can be used to pattern the lithium metal layer so that a precise pattern of lithium metal is removed from the flexible support layer stack.

[0033] As described, cutting systems can be used to cut or slit substrates containing metal. Accordingly, the systems and methods described herein may include metal (e.g., metal foil, metal alloy). In some embodiments, the metal is a soft metal. Some non-limiting examples of soft metals include lithium metal and other alkali metals, such as sodium (Na), potassium (K), cesium (Cs), and rubidium (Rb). The lithium metal may be a lithium metal alloy and / or may include vacuum-deposited lithium metal. In some embodiments, the soft metal may be indium or may include indium. In some embodiments, the described systems and methods may be suitable for cutting metals harder than alkali metals, such as metal foils of aluminum. Other metals are possible. In some embodiments, the metal foil has a thickness of 50 microns or less.

[0034] It should be noted that while the specific substrates on which some of the embodiments described herein may be implemented are not limited, it is particularly advantageous to implement the embodiments on flexible substrates, such as web-based substrates, panels, and individual sheets. The flexible substrate may also be in the form of a foil, a polymer film, or a thin sheet.

[0035] It is also noted in this specification that a flexible substrate or web as used in the embodiments described herein may typically be characterized in that it can be bent. The term “web” may be used synonymously with the terms “strip,” “flexible substrate,” or “flexible conductive substrate.” For example, the web described in the embodiments of this specification may be a polymer material.

[0036] It is further noted that the described methods and systems can be used to form single-sided electrode structures and double-sided electrode structures.

[0037] FIG. 1a illustrates a schematic diagram of an exemplary cutting system (100) that can be utilized to form target cut sections within a flexible support layer stack (140), such as a thin-film lithium energy storage device. The cutting system (100) is configured to accurately remove lithium films and cut underlying substrates to create slit rolls (122) from larger source rolls (120). The cutting system (100) generally includes at least one of a laser source (102), an optical source assembly (106), a pickup roller (108), a cutting assembly, e.g., a blade (118), and a controller (110) for controlling the operation of the cutting system (100). FIG. 1a illustrates a single optical source assembly (106) that generates a single laser beam (130) and a single blade (118), but the cutting system (100) may include one or more optical assemblies (106) that generate multiple laser beams (130) and a corresponding number of blades (118) to cut a flexible support layer stack (140) into multiple strips.

[0038] The cutting system (100) includes a supply roller (101) or unwinder for supplying source rolls (120) of a flexible support layer stack (140), and a winding roller (104) or winder for collecting slit rolls (122) of a flexible support layer stack (140). The flexible support layer stack (140) moves from the supply roller (101) to the winding roller (104) in the direction of movement indicated by the arrow (103). The cutting system (100) may include other rollers or intermediate rollers not shown for brevity.

[0039] The flexible support layer stack (140) has a front or front surface (140f) and a back or back surface (140b) facing the front surface (140f). Referring to FIGS. 3a through 3d, the flexible support layer stack comprises a flexible support layer (212). The flexible support layer (212) has a front surface (212f) (also referred to as the front surface) and a back surface (212r) (also referred to as the back surface) facing the front surface (212f). The flexible support layer (212) may comprise any suitable material compatible with target processing conditions. In some embodiments, the flexible support layer (212) comprises a plurality of sublayers. In one or more embodiments that may be combined with other embodiments, the flexible support layer (212) may be or comprise one or more layers selected from plastics, polymer materials, metallized plastics, metals, paper, multilayers thereof, or combinations thereof. Suitable polymer materials include polymer materials that are transparent to laser light and have little or no photon absorption to prevent overheating and fire accidents. Examples of suitable polymer materials include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), poly(methyl methacrylate) (PMMA), cellulose triacetate (TAC), polypropylene (PP), polyethylene (PE), polycarbonate (PC), multilayers thereof, or combinations thereof. In one or more embodiments that may be combined with other embodiments, the flexible support layer (212) is a web-based substrate as illustrated in FIG. 1a.

[0040] The flexible support layer stack (140) may further include a release layer (not shown). The release layer may be formed on the front surface (212f) of the flexible support layer (212). The release layer may be any material suitable for releasing subsequently formed materials from the flexible support layer (212), for example, during a substrate independent direct transfer (SIDT) process, or may include such a material.

[0041] The flexible support layer stack (140) further comprises an alkali metal film, for example, a lithium film (214). Referring to FIG. 3a, the alkali metal film, for example, a lithium film (214) is formed on the front surface (212f) of the flexible support layer (212) or on a release layer (if present). The lithium film (214) comprises a front surface (214f) (also referred to as the front surface) and a back surface (214r) (also referred to as the back surface) facing the front surface (214f). In one or more embodiments where a release layer is present, the lithium film (214) may be formed directly on the release layer. In one or more embodiments as shown in FIG. 3a, the lithium film (214) is formed directly on the front surface (212f) of the flexible support layer (212). The lithium film (214) may be lithium or may contain lithium. The lithium film (214) may be deposited under vacuum. The lithium film (214) can be deposited under vacuum within a roll-to-roll deposition system, for example, through a physical vapor deposition process, for example, an evaporation process or a sputtering process. The evaporation process may be an electron beam evaporation process or a thermal evaporation process.

[0042] The cutting system (100) further comprises at least one of a laser source (102) and an optical source assembly (106). The laser source (102) is configured to generate a laser beam (130), and the optical source assembly (106) is configured to direct the laser beam (130) toward a back surface (140b) of a flexible support layer stack (140), for example, a back surface (212r) of a flexible support layer (212).

[0043] Generally, the laser source (102) may be a solid-state laser, such as a diode-pumped solid-state laser having a fiber, rod, or slab gain medium configured to generate a laser beam (130) for irradiating the flexible support stack (140) to form one or more cuts within the flexible support stack (140). The laser beam (130) may be a continuous or pulsed laser beam. The laser fiber, rod, or slab may be formed from any suitable laser crystal material including neodymium-doped yttrium aluminum garnet (Nd:YAG; Nd:Y3Al5O12), ytterbium-doped YAG (Yb:YAG), neodymium-doped yttrium orthovanadate (Nd:YVO; Nd:YVO4), and alexandrite. In certain embodiments, the laser rod or slab has face pumping geometry. In certain embodiments, the laser slab has edge pumping geometry. Other types of lasers, such as fiber lasers or gas lasers, may be used.

[0044] In certain embodiments, the laser source (102) is an infrared laser source configured to operate at infrared (IR) wavelengths to remove sections of lithium on lithium-coated substrates. The laser source (102) can generate a pulsed laser beam (130). In the embodiments described herein, the frequency, pulse width, and pulse energy of the laser beam (130) generated by the laser source (102) are tunable (e.g., adjustable) depending on the material to be removed, the target lateral dimensions of the sections to be removed, as well as the depth of removal. Additionally, the travel speed of the laser beam (130), the number of pulses, and the beam profile and focused spot size can be tuned.

[0045] In any form, a laser beam (130) generated by a laser source (102) is projected (e.g., transmitted) toward a flexible support layer stack (140) through an optical source assembly (106). The optical source assembly (106) is optically coupled to the laser source (102) and includes any suitable image projection device for directing the laser beam (130) toward the flexible support layer stack (140) for laser activation. In certain embodiments, the optical source assembly (106) includes a scanner (132), such as a single-axis or multi-axis large-angle galvanometer optical scanner (i.e., a galvanometer scanner). The term "galvanometer scanner" refers to any device that responds to an electronic signal from a controller (110) to change the projection or reflection angle of the laser beam (130) to sweep the laser beam (130) across the flexible support layer stack (140). The scanner (132) may also be a polygon scanner, an electro-optical scanner, an acousto-optical scanner, or a combination thereof. The use of the scanner (132) enables the simultaneous activation of multiple sections of lithium on the flexible support stack (140) through a laser lift-off process in addition to scanning the laser beam (130) across the surface of the flexible support stack (140) without mechanical translation of the flexible support stack (140) itself. The scanner (132) may further include any suitable features to facilitate the activation of the materials and structures described herein, such as digital servo feedback, low drift, fast dynamic response, and precise calibration capability.

[0046] In one or more embodiments that can be combined with other embodiments, the optical source assembly (106) further comprises one or more scan lenses (134) having a wide field of view covering the entire flexible support layer stack (140). In one or more embodiments that can be combined with other embodiments, two or more scan lenses (134) may be utilized for laser removal of different types of materials, and each scan lens of the scan lenses (134) is specific to the wavelength range of the laser source (102). The scan lenses (134) may be telecentric lenses, F-theta lenses, or a combination thereof. During operation, the laser beam (130) projected by the optical source assembly (106) is directed toward the back surface (140b) of the flexible support layer stack (140).

[0047] The cutting system (100) further includes a pickup roller (108) for removing lithium metal from a lithium film (214) exposed to a laser beam (130) from a flexible support layer (212). The pickup roller (108) is positioned to contact the lithium film (214) on the front surface (140f) of the flexible support layer stack (140). The pickup roller (108) may be positioned opposite an optical source assembly (106) that generates the laser beam (130). Although the pickup roller (108) is shown aligned with the optical source assembly (106), the pickup roller (108) may be positioned downstream from the optical source assembly (106) and on the opposite side of the flexible support layer (212). The pickup roller (108) may be any suitable material that is attached to the lithium metal and capable of removing the lithium metal, or may include such material. The material of the pickup roller (108) may be selected from any suitable metal or polymer material. In one example, the pickup roller (108) may be stainless steel or may include stainless steel.

[0048] In one or more embodiments that may be combined with other embodiments, the cutting system further comprises a scraping tool, e.g., a doctor blade (170). The doctor blade (170) is positioned to remove a lithium metal film present on the pickup roller (108). As the pickup roller (108) removes the activated lithium metal from the lithium film (214), the removed lithium metal film accumulates on the surface of the pickup roller (108). The doctor blade (170) removes the accumulated lithium metal film from the surface of the pickup roller (108), thereby providing a clean surface to which additional lithium metal can be attached.

[0049] In one or more embodiments that may be combined with other embodiments, the cutting system (100) further comprises a sacrificial membrane (113), e.g., a plastic membrane, for removing lithium metal from a lithium membrane (214) exposed to a laser beam (130) from a flexible support layer (212). Referring to FIG. 1a, a pickup roller (108) pushes the sacrificial membrane (113) against the activated lithium metal of the lithium membrane (214), and the activated lithium metal is attached to the sacrificial membrane (113) and removed from the flexible support layer (212). In some embodiments, as shown in FIG. 1a, the cutting system (100) further comprises a sacrificial membrane supply roller (109) for supplying the sacrificial membrane (113), and a sacrificial membrane collection roller (111) for collecting the sacrificial membrane (113). As illustrated in FIG. 1a, a sacrificial membrane (113) is wound around a pickup roller (108), and the pickup roller (108) pushes the sacrificial membrane (113) against an activated lithium metal membrane, the activated lithium metal membrane is attached to the sacrificial membrane (113), and the sacrificial membrane (113) with the lithium metal attached is collected by a sacrificial membrane collection roller (111). In some embodiments, the activated lithium metal is contacted by the pickup roller (108) without the sacrificial membrane (113) and is attached directly to the pickup roller (108).

[0050] The cutting system (100) further comprises a blade (118). The blade (118) is positioned to cut or slit portions of the flexible support layer along a target path, for example, portions of the flexible support layer (212) exposed by the removal of lithium metal from the lithium film (214). The blade (118) is positioned downstream from the optical source assembly (106) and the pickup roller (108). The blade (118) may be any blade suitable for cutting or slitting the flexible support layer (212). The blade (118) may be a stationary blade, a rotary blade, a reciprocating blade, or other suitable mechanical cutting mechanism. The blade (118) may be in the form of a die. The die may be configured to cut the flexible support layer (212) in a closed shape. In one or more embodiments that may be combined with other embodiments, the blade (118) is positioned on a blade stage (116) or other support structure. The blade stage (116) may be coupled to an optical bench (114). The blade (118) may be positioned so that the flexible support layer stack (140) reaches the blade (118) after the lithium metal is removed from the lithium film (214) by the optical source assembly (106) and the pickup roller (108). For example, the blade (118) may cut the flexible support layer (212) parallel to the direction of movement indicated by the arrow (103) of the flexible support layer stack (140). The blade (118) can cut the flexible support layer (212) across the width of the flexible support layer (212) perpendicular to the direction of movement, for example, indicated by the arrow (103) of the flexible support layer stack (140). In one or more embodiments that can be combined with other embodiments, the blade (118) can move along the z-axis, x-axis, and y-axis.

[0051] The blade (118) may be any suitable material for cutting the flexible support layer (212) or may include it. In one or more embodiments that may be combined with other embodiments, the blade (118) may be a metal such as titanium, aluminum, steel, or a combination thereof or may include it. In one or more embodiments that may be combined with other embodiments, the blade (118) may be a polymer, for example, a hard polymer or may include it. In one or more embodiments that may be combined with other embodiments, the blade (118) may be a ceramic material or may include it. Other materials are also possible. In some embodiments, the blade (118) may be serrated. However, in other embodiments, the blade (118) is free of serrations.

[0052] The cutting system (100) may further include a controller (110). The controller (110) may include a central processing unit (CPU) (not shown), memory (not shown), and support circuits (or I / O) (not shown). The CPU may be any type of computer processor used in industrial sites to control various processing and hardware (e.g., laser sources, optical assemblies, scanners, stage motors, and other hardware) and to monitor processes (e.g., processing time, stage and / or wafer nest position, and substrate position). The memory (not shown) is connected to the CPU and may be one or more of readily available memory, such as local or remote random access memory (RAM), read-only memory (ROM), floppy disks, hard disks, or any other form of digital storage. Software instructions and data may be coded and stored in memory to instruct the CPU. Support circuits (not shown) are also connected to the CPU to support the processor in a conventional manner. Support circuits may include conventional caches, power supplies, clock circuits, input / output circuits, subsystems, etc. A program (or computer instructions) readable by the controller (110) determines which operations can be performed on the flexible support layer stack (140). The program may be software readable by the controller (110) and may include, for example, code for monitoring and controlling the laser beam (130) characteristics (frequency, pulse width, and pulse energy) and the movement of the scanner (132) (e.g., switching between them).

[0053] FIG. 1b illustrates a schematic diagram of another exemplary cutting system (160) for cutting or slitting metals according to one or more embodiments of the present disclosure. The cutting system (160) is similar to the cutting system (100). However, the cutting system (160) replaces the blade (118) shown in FIG. 1a with a second optical source assembly (152) and a second laser source (150). The laser source (150) is configured to generate a laser beam (154), and the optical source assembly (152) is configured to direct the laser beam (154) toward the front surface (140f) of the flexible support layer stack (140), for example, the front surface (212f) of the flexible support layer (212). The second laser source (150) is configured to generate a second laser beam (154) for cutting or slitting portions of the flexible support layer (212) along a target path, for example, portions of the flexible support layer (212) exposed by removing lithium metal from the lithium film (214).

[0054] The cutting system (160) may further include a second optical source assembly (152). The second optical source assembly (152) may include a scanner (156) and a scan lens (158). Although the second optical source assembly (152) is shown in FIG. 1b as being positioned to direct the second laser beam (154) toward the front surface (140f) of the flexible support layer stack (140), the second optical source assembly (152) may be positioned to direct the laser beam toward the back surface (140b) of the flexible support layer stack (140).

[0055] The second optical source assembly (152) can be positioned so that the flexible support layer stack (140) reaches the second laser beam (154) after the removal of lithium metal from the lithium film (214) by the optical source assembly (106) and the pickup roller (108). For example, the second laser beam (154) can cut the flexible support layer (212) parallel to the direction of movement indicated by the arrow (103) of the flexible support layer stack (140). The second laser beam (154) can cut the flexible support layer (212) across the width of the flexible support layer (212), for example, perpendicular to the direction of movement indicated by the arrow (103) of the flexible support layer stack (140).

[0056] The second laser source (150) can generate a second laser beam (154). In the embodiments described herein, the frequency, pulse width, and pulse energy of the second laser beam (154) generated by the second laser source (150) are tunable (e.g., adjustable) according to the material being cut, the target lateral dimensions of the sections being cut, as well as the depth of the cut. Additionally, the travel speed, number of pulses, and beam profile and focusing spot size of the second laser beam (154) can be tunable.

[0057] In any form, a second laser beam (154) generated by the second laser source (150) is projected (e.g., transmitted) toward the flexible support layer stack (140) through the second optical source assembly (152). The second optical source assembly (152) is optically coupled to the second laser source (150) and includes any suitable image projection device for directing the second laser beam (154) toward the flexible support layer stack (140) for laser activation. In certain embodiments, the second optical source assembly (152) includes a scanner (156), such as a single-axis or multi-axis large-angle galvanometer optical scanner (i.e., a galvanometer scanner). The term “galvanometer scanner” refers to any device that responds to an electronic signal from a controller (110) to change the projection or reflection angle of the second laser beam (154) to sweep the second laser beam (154) across the flexible support layer stack (140). The scanner (156) may also be a polygon scanner, an electro-optical scanner, an acousto-optical scanner, or a combination thereof. The use of the scanner (156) enables simultaneous cutting of multiple sections of the flexible support layer (212) of the flexible support layer stack (140) through laser cutting, in addition to scanning the second laser beam (154) across the surface of the flexible support layer stack (140) without mechanical translation of the flexible support layer stack (140) itself. The scanner (156) may further include any suitable features to facilitate cutting of the materials and structures described herein, such as digital servo feedback, low drift, fast dynamic response, and precise calibration ability.

[0058] In one or more embodiments that may be combined with other embodiments, the second optical source assembly (152) further comprises one or more scan lenses (158) having a wide field of view covering the entire flexible support layer stack (140). In one or more embodiments that may be combined with other embodiments, two or more scan lenses (158) may be utilized for laser cutting of different types of materials, each scan lens (158) being specific to the wavelength range of the second laser source (150). The scan lenses (158) may be telecentric lenses, F-theta lenses, or a combination thereof. During operation, the second laser beam (154) projected by the second optical source assembly (152) is directed toward either the back surface (140b) of the flexible support layer stack (140) or the front surface (140f) of the flexible support layer stack (140).

[0059] In one or more embodiments that may be combined with other embodiments, the second laser source (150) generates a CO2 laser. The CO2 laser has a wavelength suitable for cutting polymer materials. In some embodiments, the CO2 laser has a wavelength of 10.6 micrometers or less, for example, 9.4 micrometers or 9.6 micrometers.

[0060] In one or more embodiments that can be combined with other embodiments, the second laser source (150) generates a CO laser. The CO laser has a wavelength suitable for cutting polymer materials. In some embodiments, the CO laser has a wavelength of 6 micrometers or less, for example, in the range of about 5 micrometers to about 6 micrometers.

[0061] FIG. 2 illustrates a plan view of a flexible support layer stack, e.g., a flexible support layer stack (140), being processed in a cutting system, e.g., a cutting system (100), according to one or more embodiments of the present disclosure. The flexible support layer stack (140) may be formed by any suitable deposition process. The flexible support layer stack (140) comprises a flexible support layer (212). The flexible support layer stack (140) further comprises a lithium film (214). The lithium film (214) may be formed on the front surface (212f), the back surface (212r), or both the front surface (212f) and the back surface (212r) of the flexible support layer (212).

[0062] The flexible support layer stack (140) illustrated in FIG. 2 may be, for example, a negative electrode for a secondary battery, such as a negative electrode or anode for a lithium battery. According to some examples described herein, the flexible negative electrode for a lithium battery comprises a flexible support layer (212) which may be a current collector having a thickness of 10 μm or less, typically 8 μm or less, advantageously 7 μm or less, specifically 6 μm or less, particularly 5 μm or less, and containing copper. The flexible support layer stack (140) further comprises a lithium film stack having a thickness of 5 μm or more and / or 15 μm or less, containing lithium.

[0063] In one or more embodiments that may be combined with other embodiments, the flexible support layer (212) may be a flexible conductive substrate comprising, composed of, or composed essentially of a metal such as copper (Cu) or nickel (Ni). Furthermore, the flexible support layer (212) may comprise one or more sublayers. Examples of metals that the current collectors may comprise include aluminum (Al), copper (Cu), zinc (Zn), nickel (Ni), cobalt (Co), tin (Sn), silicon (Si), manganese (Mn), magnesium (Mg), alloys thereof, or combinations thereof. In certain embodiments, the web or the flexible support layer (212) may be a polymer material or may comprise a polymer material. The polymer material may be a resin film selected from a polypropylene film, a polyethylene terephthalate (PET) film, a polyphenylene sulfide (PPS) film, and a polyimide (PI) film.

[0064] In one or more embodiments that may be combined with other embodiments, the flexible support layer (212) has a thickness of about 25 μm or less, or 20 μm or less, or 15 μm or less, or 3 μm or more, or 5 μm or more. In one example, the flexible support layer (212) has a thickness in the range of about 4.5 μm to about 10 μm. The flexible support layer (212) may be thick enough to provide the intended function and thin enough to be flexible. Specifically, the flexible support layer (212) may be as thin as possible so that the flexible support layer (212) can still provide the intended function. The flexible support layer (212) may have a width of about 3000 millimeters or less, for example, in the range of about 100 millimeters to about 2400 millimeters, or in the range of about 1200 millimeters to about 2000 millimeters. The flexible support layer (212) may have a width of about 1200 millimeters or less, for example, in the range of about 100 millimeters to about 1200 millimeters.

[0065] In one or more embodiments that may be combined with other embodiments, the lithium film (214) may have a thickness of 20 μm or less, or 8 μm or less, or 7 μm or less, or 6 μm or less, or 5 μm or less. In one example, the lithium film (214) has a thickness in the range of about 1 μm to about 20 μm.

[0066] The flexible support layer stack (140) may be cut or slit using the laser and blade combination systems and methods described herein, for example, a cutting system (100). The flexible support layer stack (140) may be a lithium metal anode structure, for example, a lithium film formed on a PET substrate. The flexible support layer stack (140) may be a lithiated or pre-lithiated anode structure. The flexible support layer stack (140) illustrated in FIGS. 2 and FIGS. 3a through 3c comprises a flexible support layer (212) or a web having a lithium film stack or a lithium film (214) formed on top. During processing, the flexible support layer (212) is transported in the direction of movement indicated by the arrow (103). In one embodiment that may be combined with other embodiments, the lithium film stack or the lithium film (214) is a lithium metal film. In another embodiment that can be combined with other embodiments, the lithium film stack comprises a lithium metal film and additional films, such as an anode film, for example, a graphite film having a lithium metal film formed on top.

[0067] Each lithium film (214) comprises a lithium film and optionally additional films. Although the lithium film (214) of FIGS. 2 and FIGS. 3a through 3c is depicted as a single layer on the front surface (212f) of the flexible support layer (212), those skilled in the art should understand that the lithium film (214) may be a lithium film stack comprising a greater number of layers that may be provided above, below, and / or between the flexible support layer (212) and the lithium film (214). Although depicted as a single-sided structure, those skilled in the art should understand that the flexible support layer stack (140) may also be a double-sided structure having a lithium film (214) formed on the front surface (212f) of the flexible support layer (212) and a second lithium metal film stack (not depicted) formed on the back surface (212r) of the flexible support layer (212).

[0068] A source roll (120) including a flexible support layer stack (140) can be placed on a supply roller (101). The flexible support layer stack (140) can be supplied to a cutting system (100). A laser beam (130) activates one or more portions of a lithium film (214), and then uses pickup rollers (108a-b) (collectively referred to as 108) to remove one or more activated portions of the lithium film (214) from the flexible support layer (212), thereby creating at least one blade cutting zone (216a-b) of width "L1" between two or more segments (214a, 214b, 214c) of each of one or more lithium films (214). At least one blade cutting zone (216a-b) is shown in FIG. 2 as being located at a point one-third of the width of the flexible support layer stack (140) from the edge of the lithium film (214), but may be located at any target position on the flexible support layer stack (140). For example, at least one blade cutting zone (216a-b) may be located along the longitudinal centerline of the flexible support layer stack (140). The width "L" generated by the laser beam (130) and the pickup rollers (108a-b) must be greater than the width of the blade (118a-b), for example, about 5 mm or less, for example, about 3 mm or less, for example, about 1 mm or less, for example, about 0.1 mm or less. After the removal of the portion of the activated lithium metal, the flexible support layer stack (140) undergoes blade cutting at the blade (118a-b). The blade (118a-b) cuts the flexible support layer (212) within at least one blade cutting zone (216a-b). Preferably, the blade (118a-b) cuts the flexible support layer (212) along the centerline of the blade cutting zone (216a-b). The blade cutting produces two or more slit rolls (122a-c), such as a first slit roll (122a), a second slit roll (122b), and a third slit roll (122c).

[0069] FIG. 3a illustrates a side cross-sectional view of a flexible support layer stack (140) taken along line 3a-3a of FIG. 2 prior to laser activation, lithium removal, and blade cutting, according to one or more embodiments of the present disclosure. The flexible support layer stack (140) comprises a lithium film (214) formed on the front surface (212f) of the flexible support layer (212). Although a single lithium film is shown in FIG. 3a, additional lithium metal films, for example, a second lithium metal film positioned on the back surface (212r) of the flexible support layer (212), are considered.

[0070] FIG. 3b illustrates a side cross-sectional view of a flexible support layer stack (140) taken along line 3b-3b of FIG. 2 after the laser activation process but before the removal of the activated lithium metal. As shown in FIG. 3b, one or more portions of one or more lithium films (214) are activated by a laser beam to form activated lithium metal portions (302a-b).

[0071] FIG. 3c illustrates a side cross-sectional view of a flexible support stack (140) taken along line 3c-3c of FIG. 2 after the removal of activated lithium metal from the flexible support stack (140) and before blade cutting. As shown in FIG. 3c, each portion of one or more lithium membranes (214) is removed from the front (212f) of the flexible support layer (212) by pickup rollers (108-b) to create blade cutting zones (216a-b) in each of one or more lithium membranes (214). The blade cutting zone (216a) separates segment (214a) from segment (214b) by a width "L", and the blade cutting zone (216b) separates segment (214b) from segment (214c) by a width "L".

[0072] FIG. 3d illustrates a cross-sectional view of a flexible support layer stack (140) taken along line 3d-3d of FIG. 2 after the blade cutting process. The blades (118a-b) slit the flexible support layer (212) into three substrate segments (212a-c), which are wound onto a first slit roll (122a), a second slit roll (122b), and a third slit roll (122c).

[0073] The selection of laser parameters, such as pulse width, may be essential for developing a successful laser lift-off and blade cutting combination process that achieves clean blade cutting lanes while minimizing damage to the substrate placed underneath during the laser lift-off process. Based on laser-material interactions specific to lithium material stacks, high-frequency nanosecond-pulsed IR lasers or picosecond-pulsed IR lasers may be used. Lithium is unique in that its melting point is only 453.65 K (180.50 °C), while its boiling point remains very high at 1603 K (1330 °C). In contrast, PET has a melting point of 523 K (250 °C) and a boiling point of 623 K (350 °C). For conductive substrates such as copper, there is a much lower absorption rate for IR lasers compared to green (~520 to 540 nm) or UV lasers (< 360 nm). For example, at ambient temperature, a 1064-nanometer laser has an optical absorption rate of less than 5% in copper, whereas a 532-nanometer green laser has an optical absorption rate of approximately 40% in copper. In liquid molten copper, the 1064-nanometer laser still has an optical absorption rate of about 5%. From the perspective of avoiding copper damage, a 1 μm IR laser wavelength is more advantageous than green or UV laser wavelengths. Additionally, when using the same type of laser at the same average power level, the IR laser is more reliable and cost-effective.

[0074] IR nanosecond lasers with pulse durations of less than 30 nanoseconds and near-infrared wavelengths of 1064 nanometers are more suitable for this LLO process. However, ultrashort pulse lasers can be used for some purposes, such as quality improvement. Lasers with longer pulse durations generate a higher density plasma, resulting in greater gas pressure to deform the interface between PET and lithium. However, pulse durations longer than 50 nanoseconds entail much higher pulse energy (or laser power) due to lower peak power. Conversely, shorter pulse durations allow for more precise processing, enabling the achievement of cleaner lithium edges.

[0075] Laser parameters can be selected with advantages and benefits, such as providing laser intensity high enough to achieve lithium removal and minimize damage to the underlying substrate. Additionally, parameters can be selected to provide meaningful process throughput for industrial applications with precisely controlled ablation width (e.g., kerf width) and depth. As previously mentioned, ultrashort pulse (USP) lasers (e.g., lasers with pulse durations maximum in the femtosecond range), such as femtosecond or picosecond pulse lasers, are suitable for providing these benefits. These pulse width ranges for USPs can be 5 fs to 999 fs, preferably 10 fs to 999 fs for femtosecond pulse lasers and 1 ps to 10 ps for picosecond pulse lasers. With respect to USPs, shorter pulse widths result in higher peak power and fewer thermal effects. This increases control over the removal rate. For example, a 10 fs pulse has a peak power 1,000 times higher than a 10 ps pulse of the same pulse energy. Therefore, the wavelength range is less important, as cutting can be stopped at a precise depth to remove a specific amount or thickness of lithium without causing thermal damage to the substrate underneath.

[0076] However, since pulses longer than tens of picoseconds will begin to exhibit more distinct thermal effects, nanosecond pulse laser lift-off is also suitable. Nanosecond pulse lasers are also more cost-effective, but certain wavelengths may provide superior performance compared to others. For PET substrates, wavelength ranges of approximately 450 nm to approximately 1600 nm, or approximately 450 nm to approximately 1550 nm, will facilitate the laser lift-off of lithium using nanosecond pulses, ensuring that the PET film is highly transparent to light. Wavelengths below 450 nm, or below 355 nm, will result in scribing or cutting of the PET substrate. For polyimide (PI) substrates, wavelength ranges of approximately 700 nm to approximately 1700 nm, or approximately 750 nm to approximately 1600 nm, will provide the laser lift-off of lithium using nanosecond pulses. Similarly, wavelengths below 450 nm will result in scribing or cutting of the PI substrate.

[0077] Nanosecond pulses may be in the range of about 1 ns to about 200 ns, or in the range of about 1 ns to about 50 ns, or in the range of about 1 ns to about 10 ns. For example, in one embodiment, a nanosecond pulse laser process having a wavelength closer to or in the IR range provides a cleaner cutting process than a nanosecond pulse laser process having a wavelength closer to or in the UV range. In this specific embodiment, a femtosecond pulse laser process suitable for scribing semiconductor wafers or substrates is based on a laser having a wavelength of about 1 micrometer or more. In this specific embodiment, pulses of about 15 nanoseconds or less of a laser having a wavelength of about 1 micrometer or more are used. However, in an alternative embodiment, dual laser wavelengths (e.g., a combination of an IR laser and a UV laser) may be used.

[0078] The embodiments of the present disclosure described above have many advantages, including reduced slitting defects, in which the cutting blade does not collect reactive metal or alloy films. The safe removal of adhesive reactive metal or alloy before slitting or cutting increases the cutting blade life and the time between maintenance cycles. This reduces or eliminates periodic maintenance commonly used to remove particle debris accumulation on the cutting blade, thereby making it possible to slit long webs without periodic maintenance. However, the present disclosure does not require that all advantageous features and all advantages be incorporated into all embodiments of the present disclosure.

[0079] References are made to specific features of the present disclosure (including methods and operations) in the Description and Detailed Description of the Invention, the claims, and the accompanying drawings. It should be understood that the disclosure in this specification includes all possible combinations of such specific features. For example, where a specific feature is disclosed in the context of a specific aspect, embodiment, or example of the present disclosure, or in a specific claim, that feature may also be used in combination with other specific aspects and embodiments of the present disclosure and / or in the context thereof, and generally in the present disclosure, to the extent possible.

[0080] The embodiments and all functional operations described herein may be implemented in digital electronic circuits, or in computer software, firmware, or hardware, including, or in combinations thereof, the structural means and their structural equivalents disclosed herein. The embodiments described herein may be implemented as one or more non-transient computer program products, namely, one or more computer programs tangibly embodied in a machine-readable storage device for execution by a data processing device, e.g., a programmable processor, a computer, or a plurality of processors or computers, or for controlling the operation thereof.

[0081] The processes and logic flows described in this specification may be performed by one or more programmable processors that execute one or more computer programs to perform functions by operating on input data and generating outputs. The processes and logic flows may also be performed by a special-purpose logic circuit, such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC), and the device may also be implemented as a special-purpose logic circuit.

[0082] The term “data processing device” encompasses all devices, devices, and machines for processing data, including, for example, programmable processors, computers, or multiple processors or computers. In addition to hardware, a device may include code that creates an execution environment for the computer program in question, such as processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of these. Processors suitable for executing the computer program include, for example, both general-purpose and special-purpose microprocessors, and any one or more processors of any type of digital computer.

[0083] Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices, including, for example, semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and memory may be supplemented by or integrated into a special-purpose logic circuit.

[0084] The term “comprising” and its grammatical equivalents are used herein to mean that other components, elements, actions, etc. are optionally present. For example, an article “comprising” (or “comprising the same”) components A, B, and C may be composed of components A, B, and C (i.e., only may be composed of), or may include components A, B, and C as well as one or more other components. Additionally, whenever a composition, element, or group of elements is preceded by the transitional phrase “comprising” or its grammatical equivalents, it is understood that the same composition or group of elements may be preceded by the transitional phrases “composed of as an essential element,” “composed of,” “selected from a group composed of,” or “is,” and vice versa.

[0085] Where reference is made in this specification to a method comprising two or more defined actions, the defined actions may be performed in any order or simultaneously (except where the context excludes such possibility), and the method may include one or more other actions performed before any one of the defined actions, between two of the defined actions, or after all of the defined actions (except where the context excludes such possibility).

[0086] When introducing the elements of the present disclosure or exemplary aspects or embodiments thereof, the articles (“a,” “an,” “the,” and “said”) are intended to indicate that there is one or more of the elements.

[0087] Although the foregoing relates to embodiments of the present disclosure, other and additional embodiments of the present disclosure may be devised without departing from the basic scope of the present disclosure, and the scope of the present disclosure is determined by the subsequent claims.

Claims

Claim 1 A system for slitting a flexible support layer stack, comprising: a laser source configured to generate a laser beam ― said laser beam directed toward a first surface of the flexible support layer stack ―; an optical scanner configured to direct the laser beam toward the first surface of the flexible support layer stack ―; a pickup roller positioned opposite the laser beam ― said pickup roller is positioned to contact a second surface of the flexible support layer stack, said second surface facing the first surface ―; and a cutting assembly positioned downstream of the laser beam. Claim 2 In claim 1, the system wherein the laser source is an infrared laser source. Claim 3 A system according to claim 1, wherein the flexible support layer stack has an alkali metal film formed on the first surface. Claim 4 A system according to claim 3, wherein the flexible support layer stack comprises a polymer material selected from polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), poly(methyl methacrylate) (PMMA), cellulose triacetate (TAC), polypropylene (PP), polyethylene (PE), polycarbonate (PC), multilayers thereof, or combinations thereof. Claim 5 In claim 1, the cutting assembly comprises a rotary blade, in a system. Claim 6 In paragraph 5, the cutting assembly further comprises a blade stage, in a system. Claim 7 In claim 1, the cutting assembly comprises a second optical scanner configured to direct a second laser beam toward the flexible support layer stack. Claim 8 A system according to claim 1, further comprising a supply roller for supplying the flexible support layer stack and a take-up roller for collecting the cut flexible support layer stack. Claim 9 In claim 1, the system wherein the pickup roller comprises stainless steel. Claim 10 As a slitting device, a laser unit — the laser unit is: Optical assembly; A laser source coupled to the above optical assembly; and A slitting device comprising: a controller coupled to the optical assembly; a blade assembly positioned downstream of the laser unit; and a pickup roller positioned upstream of the blade assembly and opposite to the optical assembly. Claim 11 A slitting device according to claim 10, wherein the laser source is a solid-state laser configured to generate a continuous laser beam. Claim 12 In paragraph 10, the laser source is a solid-state laser configured to generate a pulsed laser beam, in a slitting device. Claim 13 In item 10, the blade assembly comprises a rotary blade, a slitting device. Claim 14 In paragraph 13, the above pickup roller is a slitting device comprising stainless steel. Claim 15 A method for slitting a coated substrate, comprising: supplying a coated substrate comprising at least one coating layer and a substrate layer to a laser unit; exposing a blade cutting region on the coated substrate by activating a section of the at least one coating layer from the substrate layer of the coated substrate; removing the activated section of the at least one coating layer; subsequently, supplying the coated substrate to a blade assembly; and slitting the coated substrate using the blade assembly within the blade cutting region. Claim 16 In item 15, the above laser unit is, Optical assembly; A laser source coupled to the above optical assembly; An optical bench positioned opposite to the optical assembly; and A method comprising a controller coupled to the optical assembly. Claim 17 In claim 15, the method wherein the coating layer comprises lithium. Claim 18 In claim 15, the method comprises a flexible substrate in which the substrate layer further comprises polyethylene terephthalate, polyimide, polyphenylene sulfide, alloys thereof, or combinations thereof. Claim 19 A method according to claim 15, wherein the substrate layer comprises a flexible conductive substrate further comprising copper, nickel, aluminum, zinc, cobalt, tin, silicon, manganese, magnesium, alloys thereof, or combinations thereof. Claim 20 A method according to claim 15, wherein the blade cutting region is at least one longitudinal section of the coated substrate configured to produce at least two slit-coated substrates.

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