Slitting method and hardware for coated flexible substrates

Abstract

A method and system for slitting a lithium coated polyethylene terephthalate (PET) roll is provided. The roll is subjected to laser ablation to remove a slit portion of the lithium layer that is desired to be slit, thereby exposing the underlying PET substrate. The roll is then subjected to a blade cutting process in which the roll is cut along the exposed PET substrate, resulting in a plurality of slit rolls. The laser ablation of the roll prior to blade cutting allows lithium to be removed, thereby preventing lithium build-up on the blade. This reduces maintenance time, improves the quality of the slit roll edge, and allows for cutting longer lengths of rolls. The laser ablation also allows for blade cutting of rolls with thick lithium layers.

Description

Background Art

[0001] field

[0002] Embodiments of the present invention generally relate to a laser ablation-based slicing method and apparatus for lithium thin films for use in energy storage devices.

[0003] Related technical description

[0004] Rechargeable electrochemical 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 being used in a growing number of applications, including portable electronic devices, medical treatment, transportation, large-scale energy storage devices connected to the power grid, renewable energy storage devices, and uninterruptible power supplies (UPS). In each of these applications, the charge / discharge time and capacity of the energy storage device are essential parameters. In addition, the size, weight, and / or cost of such energy storage devices are also essential parameters. In addition, low internal impedance is crucial for high performance. The lower the impedance, the fewer restrictions the energy storage device encounters when delivering electrical energy. For example, in the case of a battery, internal impedance affects performance by reducing the total amount of useful energy stored by the battery and the ability of the battery to deliver high currents.

[0005] One method for manufacturing energy storage devices is roll-to-roll processing. Efficient roll-to-roll deposition processes not only provide high deposition rates but also provide film surfaces that lack small-scale roughness, contain minimal defects, and are flat (e.g., lack large-scale topography). Furthermore, efficient roll-to-roll deposition processes provide consistent deposition results, or "repeatability."

[0006] Thin-film lithium energy storage devices typically utilize a pre-lithiation process, in which a thin lithium film is deposited on or over a substrate or web prior to lamination with the anode. The roll-to-roll process used for pre-lithiation typically requires a certain roll width for economy, even if a smaller width of the lithium-coated roll is desired. Typically, the lithium-coated roll or stack will be slit or cut using a fixed or rotating blade. However, the blades often suffer from lithium buildup, which reduces cut quality and increases maintenance time as the blades need to be replaced. Additionally, due to lithium buildup on the blades, only a small section of the stack may be cut.

[0007] Therefore, there is a need for an improved apparatus and method for singulating lithium thin films for use in energy storage devices. Summary of the Invention

[0008]

[0014] Embodiments described herein generally relate to combined laser ablation and blade dicing of lithium thin films for use in energy storage devices.

[0009] In one embodiment, a system for slitting a stack of flexible layers is provided. In this embodiment, the system includes a laser source configured to generate a laser beam, an optical scanner, and a blade assembly positioned downstream of the laser beam. Here, the optical scanner is configured to direct the laser beam toward the stack of flexible layers.

[0010] In another embodiment, a slitting apparatus is provided. In this embodiment, the slitting apparatus includes a laser unit and a blade positioned downstream of the laser unit. Here, the laser unit includes an optical assembly, a laser source coupled to the optical assembly, an optical platform positioned opposite the optical assembly, and a controller coupled to the optical assembly.

[0011] In yet another embodiment, a method for slitting a coated substrate is provided. In this embodiment, the method includes feeding a coated substrate comprising at least one coating layer and a substrate layer to a laser unit, exposing a blade cutting region by removing a section of at least one coating layer from the substrate layer of the coated substrate, then feeding the coated substrate to a blade assembly, and slitting the coated substrate using the blade assembly within the blade cutting region. Here, the laser unit includes an optical assembly, a laser source coupled to the optical assembly, an optical platform positioned opposite the optical assembly, and a controller coupled to the optical assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order that the manner in which the above-mentioned features of the present disclosure may be understood in detail, a more particular description of the present disclosure, briefly summarized above, may be made with reference to embodiments, some of which are illustrated in the accompanying drawings. It is to be noted, however, that the drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of the scope of the present disclosure, as the disclosure may admit to other equally effective embodiments.

[0013] Figure 1 A schematic diagram of an exemplary laser and blade system is shown, according to one or more embodiments of the present disclosure.

[0014] Figure 2 A top plan view of a flexible layer stack according to one or more embodiments of the present disclosure is shown.

[0015] Figures 3A to 3C One or more embodiments according to the present disclosure are shown. Figure 2 Cross-sectional side view of a flexible layer stack.

[0016] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. DETAILED DESCRIPTION

[0017] The following disclosure describes combined laser ablation and blade slitting in a roll-to-roll deposition system and methods for performing the same. To provide a thorough understanding of various embodiments, the following description and Figures 1 to 3C To avoid unnecessarily obscuring the description of the various embodiments, other details of well-known structures and systems generally associated with mechanical cutting, laser ablation, coil coating, electrochemical cells, and secondary batteries are not set forth in detail in the following disclosure.

[0018] Many of the details, dimensions, angles, and other features shown in the figures are merely illustrative of specific embodiments. Accordingly, other embodiments may have other details, components, dimensions, angles, and features without departing from the spirit or scope of the present disclosure. Additionally, further embodiments of the present disclosure may be implemented without requiring some of the details described below.

[0019] The embodiments described herein will be described below with reference to a roll-to-roll coating system. The equipment descriptions described herein should be considered illustrative and should not be interpreted or construed as limiting the scope of the embodiments described herein. It should also be understood that although described as a roll-to-roll process, the embodiments described herein can also be performed on discrete substrates.

[0020] It is worth noting that, while there is no limitation on the specific substrates on which some embodiments described herein may be practiced, it is particularly beneficial to practice these embodiments on flexible substrates, such as roll-based substrates, panels, and discrete sheets. The substrate may also be in the form of a foil, film, or sheet.

[0021] It should also be noted that the flexible substrates or webs used in the embodiments described herein can typically be characterized as being bendable. The term "web" can be used synonymously with "strip," "flexible substrate," or "flexible conductive substrate." For example, the webs described in the embodiments herein can be foils.

[0022] It is further noted that in some embodiments, when the substrate is a vertically oriented substrate, the vertically oriented substrate may be angled relative to a vertical plane. For example, in some embodiments, the substrate may be at an angle of about 1 degree to about 20 degrees relative to a vertical plane. In some embodiments, when the substrate is a horizontally oriented substrate, the horizontally oriented substrate may be angled relative to a horizontal plane. For example, in some embodiments, the substrate may be at an angle of about 1 degree to about 20 degrees relative to a horizontal plane. As used herein, the term "vertical" is defined as the primary surface or deposition surface of the flexible conductive substrate being perpendicular to a horizontal line. The term "horizontal" is defined as the primary surface or deposition surface of the flexible conductive substrate being parallel to a horizontal line.

[0023] It is further noted that, in the present disclosure, a "roll" or "roller" may be understood as a device that provides a surface with which a substrate (or a portion of a substrate) may contact while the substrate is present in a processing system. At least a portion of the "roll" or "roller" may include a circular shape to facilitate contact with a substrate to be processed or processed. In some embodiments, the "roll" or "roller" may have a cylindrical or substantially cylindrical shape. The substantially cylindrical shape may be formed about a straight longitudinal axis, or may be formed about a curved longitudinal axis. According to some embodiments, a "roll" or "roller" as described herein may be adapted to contact a flexible substrate. For example, a "roll" or "roller" as described herein may include a guide roller adapted to guide a substrate while it is being processed (e.g., in a deposition process) or while it is present in a processing system; an extension roller adapted to provide a defined tension to a substrate to be coated or patterned; a deflection roller adapted to deflect a substrate according to a defined travel path; a process roller adapted to support the substrate during processing, such as a process roller, e.g., a coating roller or coating roller; an adjustment roller, a supply roll, a take-up roll, etc. A "roll" or "roller" as described herein may comprise metal. In one embodiment, the surface of the roller arrangement that comes into contact with the substrate may be adapted to the respective substrate to be coated.

[0024] The manufacture of thin-film lithium batteries typically uses a pre-lithiation process, in which a thin lithium film is deposited on a substrate or coil on a roll. Once the substrate is coated with lithium, the stack typically needs to be slit into narrower rolls. The original or source roll of lithium-coated substrates is typically slit using a fixed or rotating blade. However, as the roll passes through the blade, lithium from the coating often adheres to the blade surface, causing blade damage, increased maintenance time, and poor edge quality, while allowing only small sections of the source roll to be slit.

[0025] Embodiments of the present disclosure that may be combined with other embodiments include a system having a laser unit to remove portions of the lithium coating before the blade. The laser unit, in combination with the blade system, allows for slitting of longer sections of the source roll, produces higher quality edges on the slit rolls, reduces maintenance time, and allows rolls with thick lithium layers to be slit.

[0026] Figure 1 A schematic diagram of an exemplary cutting system 100 is shown that can be used to form desired cuts in a flexible layer stack 140, such as a thin film lithium energy storage device. The cutting system 100 is configured to accurately ablate a lithium thin film and cut an underlying substrate to produce a slit roll 122 from a larger source roll 120. The cutting system 100 generally includes at least one of each of a laser source 102, an optical assembly 106, a blade 118, a blade station 116, and a controller 110 for controlling the operation of the cutting system 100. For example, although Figure 1While the optical assembly 106 is depicted as generating a single beam 130 and a single blade 118, the cutting system 100 may include one or more optical assemblies 106 generating multiple beams 130 and a corresponding number of blades 118 to cut the flexible layer stack 140 into multiple ribbons. In some embodiments, the cutting system 100 further includes an optical table 114. The cutting system 100 may also include a vacuum source (not shown) and a debris collector (not shown).

[0027] Generally speaking, laser source 102 can be a solid-state laser, such as a diode-pumped solid-state laser with a rod- or slab-shaped gain medium, configured to generate a continuous or pulsed laser beam 130 to illuminate the flexible layer stack 140 and form one or more cuts therein. The laser rod or slab can be made of any suitable laser crystal material, including neodymium-doped zirconium nitride (Nd:YAG; Nd:Y3Al5O12), yttrium-doped zirconium nitride (Yb:YAG), neodymium-doped zirconium vanadate (Nd:YVO4; Nd:YVO), and metamorphic garnet. In some embodiments, the laser rod or slab has a surface-pumped geometry. In some embodiments, the laser slab has an edge-pumped geometry. Other types of lasers, such as fiber lasers or gas lasers, may also be used.

[0028] In some embodiments, the laser source 102 operates at infrared (IR) wavelengths to remove portions of lithium from a lithium-coated substrate. 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 adjustable (e.g., tunable) based on the material being ablated, the desired lateral dimensions of the ablated portion, and the depth of the ablation. Additionally, the speed of the laser beam 130, the number of pulses, the beam profile, and the focal spot size can also be adjusted.

[0029] In any form, the laser beam 130 generated by the laser source 102 is projected (e.g., transmitted) through the optical assembly 106 onto the flexible layer stack 140. The optical 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 layer stack 140 for laser ablation. In some embodiments, the optical 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 changes the projection or reflection angle of the laser beam 130 in response to an electronic signal from the controller 110 to scan the laser beam 130 across the flexible layer stack 140. The scanner 132 can also be a polygon scanner, an electro-optical scanner, an acousto-optical scanner, or a combination thereof. Scanner 132 can be used to simultaneously ablate multiple lithium portions on flexible layer stack 140 and scan laser beam 130 across the surface of flexible layer stack 140 without mechanically translating flexible layer stack 140 itself. Scanner 132 can also include any suitable features to facilitate ablation of the materials and structures described herein, such as digital servo feedback, low drift, fast dynamic response, and precise calibration capabilities.

[0030] In some embodiments, the optical assembly 106 also includes one or more scan lenses 134 with a large field of view that encompasses the entire flexible layer stack 140. In some embodiments, two or more scan lenses 134 may be used to target different types of materials for laser ablation, with each scan lens 134 being specific to the wavelength range of the laser source 102. The scan lens 134 may be a telecentric lens, an F-theta lens, or a combination thereof. During operation, the laser beam 130 projected by the optical assembly 106 is directed toward the flexible layer stack 140 and the optical platform.

[0031] In certain embodiments, a blade stage 116 can be coupled to the optical platform 114 and positioned so that the flexible layer stack 140 reaches the blade stage 116 after undergoing laser ablation of the optical assembly 106. A blade 118 can be coupled to the blade stage 116 and configured to cut the flexible layer stack 140 along a desired path. The blade 118 can be a fixed blade, a rotating blade, a reciprocating blade, or other suitable mechanical cutting mechanism.

[0032] The controller 110 may include a central processing unit (CPU) (not shown), memory (not shown), and support circuitry (or I / O) (not shown). The CPU can be any form of computer processor used in an industrial environment to control various processes and hardware (e.g., laser sources, optical components, scanners, stage motors, and other hardware) and monitor processes (e.g., processing time, stage and / or wafer clamping position, and substrate position). The memory (not shown) is connected to the CPU and may include one or more types of readily available memory, such as random access memory (RAM), read-only memory (ROM), magnetic disk, hard disk, or any other form of digital storage, whether local or remote. Software instructions and data may be encoded and stored in the memory to direct the CPU. Support circuitry (not shown) is also connected to the CPU to support the processor in a conventional manner. The support circuitry may include conventional caches, power supplies, clock circuits, input / output circuits, subsystems, etc. The program (or computer instructions) readable by the controller 110 determines which tasks can be performed on the flexible layer stack 140. The program may be software readable by the controller 110 and may include code for monitoring and controlling (eg, switching) the characteristics (frequency, pulse width, and pulse energy) of the laser beam 130 and the movement of the stage 112 or scanner 132 .

[0033] Figure 2 A top view of a flexible layer stack 210 according to one or more embodiments of the present disclosure is shown. The flexible layer stack 210 can be formed by any suitable deposition process. The flexible layer stack 210 can include a flexible substrate 212. The flexible layer stack 210 can also include one or more lithium films 214 located on the top surface, the bottom surface, or both the top and bottom surfaces of the flexible substrate 212.

[0034] Figure 2 The flexible layer stack 210 shown in the figure can be a negative electrode of a secondary battery cell, such as a negative electrode or anode of a lithium battery. According to some examples described herein, the flexible negative electrode of the lithium battery includes a flexible substrate 212, which can be a current collector including copper and has a thickness of equal to or less than 10 μm, typically equal to or less than 8 μm, advantageously equal to or less than 7 μm, specifically equal to or less than 6 μm, and particularly equal to or less than 5 μm. The flexible layer stack 210 further includes a lithium film stack containing lithium and having a thickness equal to or greater than 5 μm and / or equal to or less than 15 μm.

[0035] In one embodiment that may be combined with other embodiments, the flexible substrate 212 may be a flexible conductive substrate comprising, consisting of, or consisting essentially of a metal, such as copper (Cu) or nickel (Ni). In addition, the flexible substrate 212 may include one or more sublayers. Examples of metals that may constitute the current collector 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 flexible substrate 212 may be 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. The substrate may be a flexible substrate or web, such as the flexible substrate 212, which may be used in a roll-to-roll coating system.

[0036] According to some examples described herein, the thickness of the flexible substrate 212 may be equal to or less than about 25 μm, typically equal to or less than 20 μm, specifically equal to or less than 15 μm, and / or typically equal to or greater than 3 μm, specifically equal to or greater than 5 μm. In one embodiment, the thickness of the flexible substrate 212 ranges from about 4.5 μm to about 10 μm. The flexible substrate 212 can be thick enough to provide the intended functionality while being thin enough to maintain flexibility. Specifically, the flexible substrate 212 can be as thin as possible so that it still provides its intended functionality. The width of the flexible substrate 212 can be equal to or less than about 1200 mm, for example, ranging from about 100 mm to about 1200 mm.

[0037] According to certain embodiments described herein, the thickness of the lithium film stack 214 can be equal to or less than 20 μm, typically equal to or less than 8 μm, advantageously equal to or less than 7 μm, specifically equal to or less than 6 μm, and particularly equal to or less than 5 μm. In one embodiment, the thickness of the lithium film stack 214 ranges from about 1 μm to about 20 μm.

[0038] The flexible layer stack 210 can be cut or slit using the combined laser and blade system and method described herein. The flexible layer stack 210 can be a lithium metal anode structure, for example, a lithium film formed on a PET substrate. The flexible layer stack 210 can be a lithiated or pre-lithiated anode structure. Figure 2 and Figures 3A to 3CThe flexible layer stack 210 shown in FIG. 1 includes a flexible substrate 212 or web having a lithium film or lithium film stack 214. During processing, the flexible substrate 212 is transported in the direction of travel indicated by arrow 126. In one embodiment, which may be combined with other embodiments, the lithium film or lithium film stack 214 is a lithium metal film. In another embodiment, which may be combined with other embodiments, the lithium film stack 214 includes a lithium metal film and other additional films, for example, an anode film, such as a graphite film, on which the lithium metal film is formed.

[0039] Each lithium film stack 214 includes a lithium film and optionally some additional films. Figure 2 as well as Figures 3A to 3C In the figure, the lithium film stack 214 is shown as a single layer on each side of the flexible substrate 212, but it should be understood by those skilled in the art that the lithium film stack 214 may include a greater or lesser number of layers, which may be provided above, below, and / or between the flexible substrate 212 and the lithium metal film 214. Although shown as a double-sided structure, it should be understood by those skilled in the art that the flexible layer stack 210 may also be a single-sided structure having the flexible substrate 212 and the lithium film stack 214.

[0040] The flexible layer stack 140 can be placed on a source roll 120. The flexible layer stack 140 can be fed to the cutting system 100. The laser beam 130 removes portions of one or more lithium films 214 on the flexible substrate 212 to produce at least one blade cutting area 216 having a width "L" located between two or more segments 214a, 214b of each of the one or more lithium films 214. The at least one blade cutting area 216 is formed at a width "L" between two or more segments 214a, 214b of each of the one or more lithium films 214. Figure 2 1. The width "L" should be greater than the width of the blade 118, such as about 5 mm, such as about 3 mm, such as about 1 mm, or such as about 0.1 mm. After laser ablation, the flexible layer stack 140 undergoes blade cutting at the blade 118. The blade 118 can be a fixed blade, a rotating blade, a reciprocating blade, or any suitable mechanical cutting device. The blade 118 cuts the flexible substrate 212 within at least one blade cutting area 216. Preferably, the blade 118 cuts the flexible substrate 212 on the centerline of the blade cutting area 216. Blade cutting produces two or more slit rolls 122, such as a first slit roll 122a and a second slit roll 122b.

[0041] Figure 3A Figure 2 shows a schematic diagram of a laser ablation and blade cutting process according to one or more embodiments of the present disclosure. Figure 21. A cross-sectional side view of a flexible layer stack 140. The flexible layer stack 140 in this embodiment includes two of the one or more lithium films 214 on the top and bottom surfaces of the flexible substrate 212. Figure 3A Two lithium film layers are shown in FIG, but other numbers of layers are also contemplated, such as one film layer on either the top or bottom surface of the flexible substrate.

[0042] Figure 3B FIG. 1 shows a cross-sectional side view of a flexible layer stack 140 after a laser ablation process but before a blade cutting process according to one or more embodiments of the present disclosure. Figure 3B As shown, a portion of each of the one or more lithium films 214 is removed from the surface of the flexible substrate 212, thereby forming a blade cutting area 216 in each of the one or more lithium films 214. The blade cutting area 216 separates the segment 214a from the segment 214b by a width "L".

[0043] Figure 3C Shown after laser ablation and blade cutting process Figure 2 The blade 118 slits the flexible substrate 212 into two substrate segments 212a and 212b and rolls them into a first slit roll 122a and a second slit roll 122b.

[0044] The selection of laser parameters, such as pulse width, is critical to developing a successful combined laser and blade cutting process that minimizes damage to the underlying substrate during laser ablation while achieving clean laser-scribed cuts. High-frequency nanosecond pulsed IR lasers or picosecond pulsed IR lasers can be used, based on laser-material interactions specific to lithium material stacks. Lithium is unique in that it melts at only 453.65 K (180.50 °C) and boils at 1603 K (1330 °C), which is still very high. In comparison, PET melts at 523 K (250 °C) and boils at 623 K (350 °C). The optical properties of lithium are generally difficult to obtain. For conductive substrates such as copper, its absorption of IR lasers is much lower than its absorption of green light (approximately 520 to 540 nm) or UV lasers (<360 nm). For example, at ambient temperature, a 1064-nm laser has less than 5% optical absorption in copper, while a 532-nm green laser has approximately 40% optical absorption in copper. A 1064-nm laser in molten copper still has approximately 5% optical absorption. From the perspective of avoiding copper damage, a 1μm IR laser wavelength offers advantages over green or UV laser wavelengths. Furthermore, at the same average power level and for the same laser type, IR lasers are more reliable and cost-effective.

[0045] Laser parameters can be selected based on benefits and advantages such as providing sufficiently high laser intensity to achieve lithium removal while minimizing damage to the substrate. Furthermore, parameters can be selected to provide process throughput meaningful for industrial applications and precise control over ablation width (e.g., kerf width) and depth. As mentioned above, ultrashort pulse (USP) lasers (e.g., lasers with pulse durations in the femtosecond range at most), such as femtosecond or picosecond pulse lasers, are well-suited to provide these advantages. Such pulse widths for USPs can range from 5 fs to 999 fs, preferably from 10 fs to 999 fs for femtosecond pulse lasers, and from 1 ps to 10 ps for picosecond pulse lasers. With USPs, shorter pulse widths result in higher peak power and less thermal effects. This increases control over the removal rate. For example, a 10 fs pulse has a peak power 1000 times higher than a 10 ps pulse of the same pulse energy. Consequently, wavelength range is less critical because ablation can be stopped at a precise depth, removing a specific amount or thickness of lithium without thermally damaging the underlying substrate.

[0046] However, nanosecond pulsed laser ablation is also suitable because pulses exceeding tens of picoseconds will begin to produce more significant thermal effects. Nanosecond pulsed lasers are also more cost-effective, but certain wavelengths may provide better performance than other wavelengths. For PET substrates, a wavelength range of 450nm to 1600nm, preferably 450nm to 1550nm, will facilitate laser ablation of lithium with nanosecond pulses, making the PET film very transparent to light. Wavelengths below 450nm, preferably below 355nm, will result in scratching or cutting of the PET substrate instead of ablating the surface layer of lithium. For polyimide (PI) substrates, a wavelength range of 700nm to 1700nm, preferably 750nm to 1600nm, will use nanosecond pulses to laser ablate lithium. Similarly, wavelengths below 450nm will scratch or cut the PI substrate instead of ablating the surface layer of lithium.

[0047] The nanosecond pulses may range from 1 ns to 200 ns, preferably from 1 ns to 50 ns, and more preferably from 1 ns to 10 ns. For example, in one embodiment, a nanosecond pulsed laser process having a wavelength close to or in the IR range provides a cleaner ablation process than a nanosecond pulsed laser process close to or in the UV range. In such a specific embodiment, a femtosecond pulsed laser process suitable for scribing semiconductor wafers or substrates is based on a laser having a wavelength of approximately one micron or greater. In such a specific embodiment, the laser pulses used are approximately less than or equal to 15 nanoseconds and have a wavelength of approximately one micron or greater. However, in another embodiment, dual laser wavelengths (e.g., a combination of an IR laser and a UV laser) may be used.

[0048] In another alternative embodiment, laser ablation by laser beam 130 may not completely remove lithium from at least one blade cut region 216. Doing so would result in a significant reduction in the lithium film 214 within at least one blade cut region 216, providing the advantages of the present disclosure and preventing damage to the underlying roll surface. In another alternative embodiment, laser ablation by laser beam 130 occurs outside the roll region or at a specific angle of incidence determined by the optical properties of flexible substrate 212.

[0049] The embodiments and all functional operations described in this specification can be implemented in digital electronic circuits or in the form of computer software, firmware or hardware, including the structural means disclosed in this specification and their structural equivalents or their combination. The embodiments described herein can be implemented as one or more non-transitory computer program products, that is, one or more computer programs tangibly embodied in a machine-readable storage device for execution by a data processing device (such as a programmable processor, a computer or multiple processors or computers) or to control the operation of the data processing device.

[0050] The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. These processes and logic flows can also be performed by, and the device can be implemented as, special-purpose logic circuitry, such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit).

[0051] The term "data processing apparatus" encompasses all devices, apparatus, and machines for processing data, including, for example, a programmable processor, a computer, or multiple processors or computers. In addition to hardware, an apparatus may include code that creates an execution environment for a computer program, for example, code constituting 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 a computer program include, for example, general-purpose and special-purpose microprocessors, and one or more processors of any kind of digital computer.

[0052] Computer-readable media suitable for storing computer program instructions and data include all forms of nonvolatile memory, media, and storage devices, including, for example, semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0053] When introducing elements of the present disclosure or exemplary aspects or embodiments thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements.

[0054] The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0055] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope of the disclosure, which is determined by the claims that follow.

Claims

1. A system for slitting a stack of flexible layers, the system comprising: a laser source configured to generate a laser beam; Optical scanners; as well as A blade assembly is positioned downstream from the laser beam.

2. The slitting system of claim 1, wherein the laser source is an infrared laser source.

3. The system of claim 1, wherein the optical scanner is configured to direct the laser beam toward the flexible layer stack.

4. The system of claim 1, wherein the laser beam is configured to remove at least one lithium layer from the flexible layer stack.

5. The system of claim 1, wherein the laser beam is configured to not damage a flexible substrate layer of the flexible layer stack.

6. The system of claim 5, wherein the flexible substrate layer comprises polyethylene terephthalate, polyimide, polyphenylene sulfide, or a combination thereof.

7. The system of claim 5, wherein the flexible substrate layer is a flexible conductive layer comprising copper, nickel, aluminum, zinc, cobalt, tin, silicon, manganese, magnesium, alloys thereof, or combinations thereof.

8. The system of claim 1, wherein the blade assembly comprises a blade and a blade station.

9. The system of claim 1, wherein the blade assembly comprises a stationary blade.

10. A slitting device, comprising: A laser unit, the laser unit comprising: Optical components; a laser source coupled to the optical assembly; an optical platform positioned opposite to the optical assembly; as well as a controller coupled to the optical assembly; as well as A blade is positioned downstream of the laser unit.

11. The slitting apparatus of claim 10, wherein the laser source is a solid-state laser configured to generate a continuous laser beam.

12. The slitting apparatus of claim 10, wherein the laser source is a solid-state laser configured to generate a pulsed laser beam.

13. The slitting apparatus of claim 10, wherein the laser source is configured to generate a laser beam capable of ablating a coating of the flexible layer stack.

14. The slitting apparatus of claim 13, wherein the laser source is further configured to not damage the flexible substrate of the flexible layer stack.

15. A method of slitting a coated substrate, the method comprising: feeding a coated substrate consisting of at least one coating layer and a substrate layer to a laser unit; exposing a blade cut area on the coated substrate by removing a section of the at least one coating layer from the substrate layer of the coated substrate; The coated substrate is then fed to a blade assembly; as well as The coated substrate is slit using the blade assembly within the blade cutting area.

16. The method of claim 15, wherein the laser unit comprises: Optical components; a laser source coupled to the optical assembly; an optical platform positioned opposite to the optical assembly; as well as A controller is coupled to the optical assembly.

17. The method of claim 15, wherein the coating layer comprises lithium. 18 . The method of claim 15 , wherein the substrate layer comprises a flexible substrate, the flexible substrate further comprising polyethylene terephthalate, polyimide, polyphenylene sulfide, alloys thereof, or combinations thereof.

19. The method of 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.

20. The method of 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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