Slit cutting method and hardware for coated flexible substrates

Abstract

A method and system are provided for slitting lithium-coated polyethylene terephthalate (PET) rolls. The roll is subjected to laser ablation to remove portions of the lithium layer where slitting is desired, exposing the PET substrate underneath. The roll is then subjected to a blade cutting process, which cuts the roll along the exposed PET substrate to produce multiple slit-cut rolls. Laser ablation of the roll prior to blade cutting removes the lithium and prevents lithium buildup on the blade. This reduces maintenance time, improves edge quality of the slit-cut rolls, and allows for longer roll lengths to be cut. Furthermore, laser ablation allows rolls with thicker lithium layers to be cut with the blade.

Description

[Technical Field]

[0001] Embodiments of the present invention generally relate to laser ablation-based slit cutting methods and apparatus for thin lithium films for energy storage devices. [Background technology]

[0002] Rechargeable electrochemical storage systems are becoming increasingly important in many areas of daily life. Large-capacity energy storage devices, such as lithium-ion (Li-ion) batteries and capacitors, are being used in an increasing number of applications, including portable electronics, medical care, transportation, grid-connected large-capacity energy storage, renewable energy storage, and uninterruptible power supplies (UPS). In each of these applications, the charge / discharge time and capacity of the energy storage device are fundamental parameters. In addition, the size, weight, and / or cost of such 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 total amount of useful energy stored by the battery as well as the battery's ability to deliver large currents.

[0003] One method for fabricating 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 film surface that is free of small-scale roughness, contains minimal defects, and is flat, i.e., free of large-scale irregularities. In addition, an effective roll-to-roll deposition process provides consistent deposition results, or "reproducibility."

[0004] Thin-film lithium energy storage devices typically use a prelithiation process in which a thin film of lithium is deposited on a substrate or web prior to lamination with an anode. Roll-to-roll processes for prelithiation often require a specific roll width to be economical, even if the desired width of the lithium-coated roll is smaller. Typically, the lithium-coated roll or laminate is slit or cut with a fixed or rotating blade. However, lithium tends to accumulate on the blade, reducing the quality of the cut and increasing maintenance time due to the need to replace the blade. Furthermore, lithium accumulation on the blade reduces the length of laminate that can be cut.

[0005] Therefore, there is a need for improved apparatus and methods for slitting thin lithium films for energy storage devices. Summary of the Invention

[0006] The embodiments described herein generally relate to combined laser ablation and blade slit cutting of thin lithium films for energy storage devices.

[0007] In one embodiment, a system for slit cutting a flexible laminate is provided that includes a laser source configured to generate a laser beam, an optical scanner, and a blade assembly positioned downstream of the laser beam, where the optical scanner is configured to direct the laser beam at the flexible laminate.

[0008] In another embodiment, a slit cutting device is provided, which includes a laser unit and a blade disposed downstream from the laser unit, wherein the laser unit includes an optical assembly, a laser source coupled to the optical assembly, an optical bench disposed opposite the optical assembly, and a controller coupled to the optical assembly.

[0009] In yet another embodiment, a method for slit-cutting 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; removing a portion of the at least one coating layer from the substrate layer of the coated substrate to expose a blade cutting region on the coated substrate; thereafter feeding the coated substrate to a blade assembly; and slit-cutting the coated substrate in the blade cutting region using the blade assembly. Here, the 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.

[0010] In order that the above-mentioned features of the present disclosure may be more particularly understood, the present disclosure, briefly summarized above, can be more particularly described by reference to embodiments, some of which are illustrated in the accompanying drawings. However, the accompanying drawings depict only exemplary embodiments and therefore should not be considered as limiting the scope of the present disclosure, which may admit of other equally effective embodiments. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 shows a schematic diagram of an exemplary laser and blade system in accordance with one or more embodiments of the present disclosure. [Figure 2] 1 illustrates a top view of a flexible laminate in accordance with one or more embodiments of the present disclosure. [Figure 3A] 3 illustrates a cross-sectional side view of the flexible laminate of FIG. 2 in accordance with one or more embodiments of the present disclosure. [Figure 3B] 3 illustrates a cross-sectional side view of the flexible laminate of FIG. 2 in accordance with one or more embodiments of the present disclosure. [Figure 3C] 3 illustrates a cross-sectional side view of the flexible laminate of FIG. 2 in accordance with one or more embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] For ease of understanding, the same reference numerals have been used, where possible, to designate identical elements common among the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without the need for further recitation.

[0013] The following disclosure describes slit cutting by a combination of laser ablation and a blade in a roll-to-roll deposition system, and methods for performing the same. Specific details are set forth in the following description and in FIGS. 1-3C to provide a thorough understanding of various embodiments of the present disclosure. Other details describing well-known structures and systems often associated with mechanical cutting, laser ablation, web coating, electrochemical cells, and secondary batteries are not set forth in the following disclosure to avoid unnecessarily obscuring the description of the various embodiments.

[0014] Many of the details, dimensions, angles, and other features shown in the figures are merely illustrative of particular embodiments. Thus, 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 practiced without some of the details described below.

[0015] The embodiments described herein are described below with reference to a roll-to-roll coating system. The apparatus descriptions provided herein are exemplary and should not be taken or interpreted as limiting the scope of the embodiments described herein. Although described as a roll-to-roll process, it should be understood that the embodiments described herein may also be performed on discontinuous substrates.

[0016] It should be noted that the particular substrates on which some embodiments described herein may be practiced are not limited, but it is particularly beneficial to practice the embodiments on flexible substrates, including, for example, web-based substrates, panels, and discontinuous sheets. The substrate may be in the form of a foil, film, or sheet.

[0017] It should also be noted that the flexible substrate or web used in the embodiments described herein can typically be characterized as being bendable. The term "web" can be used synonymously with the terms "strip," "flexible substrate," or "flexible conductive substrate." For example, the web described in the embodiments herein can be a foil.

[0018] It is further noted that in some embodiments where the substrate is a vertically oriented substrate, the vertically oriented substrate may be inclined relative to the vertical plane. For example, in some embodiments, the substrate may be inclined from about 1 degree to about 20 degrees from the vertical plane. In some embodiments where the substrate is a horizontally oriented substrate, the horizontally oriented substrate may be inclined relative to the horizontal plane. For example, in some embodiments, the substrate may be inclined from about 1 degree to about 20 degrees from the horizontal plane. As used herein, the term "vertical" is defined as a major surface or deposition surface of the flexible conductive substrate that is perpendicular to the horizontal. As used herein, the term "horizontal" is defined as a major surface or deposition surface of the flexible conductive substrate that is parallel to the horizontal.

[0019] It is further noted that in this disclosure, a "roll" or "roller" can be understood as a device that provides a surface with which a substrate (or a portion of a substrate) can contact when the substrate is in a processing system. At least some of the "rolls" or "rollers" referred to herein can include a circular shape for contacting a substrate to be processed or a substrate that has already been processed. In some embodiments, a "roll" or "roller" can have a cylindrical or substantially cylindrical shape. The substantially cylindrical shape can be formed about a straight longitudinal axis or a curved longitudinal axis. According to some embodiments, a "roll" or "roller" described herein can be configured to contact a flexible substrate. For example, a "roll" or "roller" referred to herein can be a guide roller configured to guide a substrate as it is being processed (such as during a deposition process) or as it resides in a processing system; a spreader roller configured to apply a predetermined tension to a substrate being coated or patterned; a deflection roller for redirecting the movement of a substrate according to a defined path; a processing roller for supporting a substrate during processing, e.g., a coating roller or a processing drum such as a coating drum; an adjustment roller; a supply roll; a take-up roll; etc. A "roll" or "roller" as described herein can include metal. In one embodiment, the surface of the roller device that contacts the substrate can be configured for each substrate being coated.

[0020] Thin-film lithium battery manufacturing typically uses a pre-lithiation process, in which a thin film of lithium is deposited onto a roll or web of substrate. After the substrate is coated with lithium, the laminate often needs to be slit into narrower rolls. The original or source roll of lithium-coated substrate is typically slit using a fixed or rotating blade. However, only short source rolls can be slit, as lithium from the coating often adheres to the blade surface as the roll passes through the blade, causing blade damage, increased maintenance time, and poor edge quality.

[0021] An embodiment of the present disclosure that can be combined with other embodiments includes a system having a laser unit for removing a portion of the lithium coating prior to the blade, which in conjunction with the blade system allows for slitting of longer source rolls, resulting in higher quality edges on the slit roll, reducing maintenance time, and allowing for slitting of rolls with thicker layers of lithium.

[0022] FIG. 1 shows a schematic diagram of an exemplary cutting system 100 that can be utilized to create desired cuts in a flexible laminate 140, such as a thin-film lithium energy storage device. The cutting system 100 is configured to precisely ablate the lithium film and cut the underlying substrate to produce slit-cut rolls 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 stage 116, and a controller 110 for controlling the operation of the cutting system 100. For example, while FIG. 1 shows one optical assembly 106 and a single blade 118 generating a single beam 130, the cutting system 100 may include one or more optical assemblies 106 and a corresponding number of blades 118 generating multiple beams 130 to cut the flexible laminate 140 into multiple strips. In certain embodiments, the cutting system 100 further includes an optical bench 114. Additionally, the cutting system 100 may include a vacuum source (not shown) and a debris collector (not shown).

[0023] Generally, the laser source 102 may be a solid-state laser configured to generate a continuous or pulsed laser beam 130 for irradiating the flexible stack 140 and forming one or more cuts, such as a diode-pumped solid-state laser having a rod or slab gain medium. The laser rod or slab may be formed of any suitable laser crystal material, including neodymium-doped yttrium aluminum garnet (Nd:YAG; Nd:YAlO), ytterbium-doped YAG (Yb:YAG), neodymium-doped yttrium orthovanadate (Nd:YVO; Nd:YVO), and alexandrite. In certain embodiments, the laser rod or slab has a face-pumped geometry. In certain embodiments, the laser slab has an edge-pumped geometry. Other types of lasers, such as fiber lasers or gas lasers, may be used.

[0024] In certain embodiments, the laser source 102 operates at an infrared (IR) wavelength to ablate portions of lithium on 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 can be adjusted (e.g., tunable) depending on the material being ablated, the desired lateral dimensions of the ablated portion, and the depth of ablation. Additionally, the translation speed, number of pulses, and beam profile and focal spot size of the laser beam 130 can be adjusted.

[0025] Regardless of its form, laser beam 130 generated by laser source 102 is projected (e.g., transmitted) toward flex stack 140 via optical assembly 106. Optical assembly 106 includes any suitable image projection device for optically coupling to laser source 102 and directing laser beam 130 toward flex stack 140 for laser ablation. In certain embodiments, optical assembly 106 includes a scanner 132, such as a single-axis or multi-axis large-angle galvanometer optical scanner (i.e., galvanometer scanner). The term “galvanometer scanner” refers to any device that changes the angle of projection or reflection of laser beam 130 in response to electronic signals from controller 110 to sweep laser beam 130 across flex stack 140. Scanner 132 may be a polygon scanner, an electro-optic scanner, an acousto-optic scanner, or a combination thereof. Utilizing a scanner 132 allows for scanning the laser beam 130 across the surface of the flex stack 140 without mechanically translating the flex stack 140 itself, as well as for simultaneously ablating multiple portions of lithium on the flex stack 140. The scanner 132 may further 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 accurate calibration capabilities.

[0026] In certain embodiments, the optical assembly 106 further includes one or more scan lenses 134 with a large field of view that encompasses the entire flex stack 140. In certain embodiments, two or more scan lenses 134 may be utilized for laser ablation of different types of materials, with each scan lens 134 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. In operation, the laser beam 130 projected by the optical assembly 106 is directed onto the flex stack 140 and the optical bench.

[0027] In certain embodiments, blade stage 116 may be coupled to optical bench 114 in an arrangement such that flex stack 140 reaches blade stage 116 after laser ablation from optical assembly 106. Blade 118 may be coupled to blade stage 116 in a configuration to cut flex stack 140 along a desired path. Blade 118 may be a fixed blade, a rotating blade, a reciprocating blade, or other suitable mechanical cutting mechanism.

[0028] 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 one of any form of computer processor used in industrial settings to control various processes and hardware (e.g., laser sources, optical assemblies, scanners, stage motors, and other hardware) and 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 random access memory (RAM), read-only memory (ROM), floppy disk, hard disk, or any other form of digital storage, local or remote. Software instructions and data may be encoded and stored in the memory for instructing the CPU. Support circuits (not shown) are also connected to the CPU for supporting the processor in a conventional manner. The support circuits may include conventional cache, power supplies, clock circuits, input / output circuits, subsystems, etc. A program (or computer instructions) readable by the controller 110 determines which tasks are performable on the flex stack 140. The program may be software readable by the controller 110 and may include, for example, code for monitoring and controlling (e.g., switching) the characteristics (frequency, pulse width, and pulse energy) of the laser beam 130 and the operation of the stage 112 or scanner 132.

[0029] 2 illustrates a top view of a flexible stack 210 in accordance with one or more embodiments of the present disclosure. The flexible stack 210 can be formed by any suitable deposition process. The flexible stack 210 can include a flexible substrate 212. Additionally, the flexible stack 210 can include one or more lithium films 214 on the top surface, the bottom surface, or both the top and bottom surfaces of the flexible substrate 212.

[0030] 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 includes a flexible substrate 212, which may be a current collector, comprising copper and having a thickness of 10 μm or less, typically 8 μm or less, beneficially 7 μm or less, particularly 6 μm or less, and especially 5 μm or less. The flexible laminate 210 further includes a lithium laminate film comprising lithium and having a thickness of 5 μm or more and / or 15 μm or less.

[0031] In one embodiment, which can be combined with other embodiments, the flexible substrate 212 may be a flexible conductive substrate that includes, consists of, or consists essentially of a metal such as copper (Cu) or nickel (Ni). Furthermore, the flexible substrate 212 may include one or more sublayers. Examples of metals that can 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 polymeric material. The polymeric material may be a resin film selected from polypropylene film, polyethylene terephthalate (PET) film, polyphenylene sulfide (PPS) film, and polyimide (PI) film. The substrate may be a flexible substrate or web, such as the flexible substrate 212 that can be used in a roll-to-roll coating system.

[0032] According to some examples described herein, the flexible substrate 212 can have a thickness of about 25 μm or less, typically 20 μm or less, particularly 15 μm or less, and / or typically 3 μm or more, particularly 5 μm or more. In one example, the flexible substrate 212 has a thickness of about 4.5 μm to about 10 μm. The flexible substrate 212 can be thick enough to provide its intended function and thin enough to be flexible. In particular, the flexible substrate 212 can be as thin as possible, as long as the flexible substrate 212 can still provide its intended function. The flexible substrate 212 can have a width of about 1200 millimeters or less, for example, from about 100 millimeters to about 1200 millimeters.

[0033] According to some examples described herein, the lithium stacked film 214 can have a thickness of 20 μm or less, typically 8 μm or less, advantageously 7 μm or less, particularly 6 μm or less, and especially 5 μm or less. In one example, the lithium stacked film 214 has a thickness of about 1 μm to about 20 μm.

[0034] The combined laser and blade systems and methods described herein can be used to cut or slit a flexible laminate 210. The flexible laminate 210 can be a lithium metal anode structure, such as a lithium film formed on a PET substrate. The flexible laminate 210 can be a lithiated or pre-lithiated anode structure. The flexible laminate 210 shown in FIGS. 2 and 3A-3C includes a flexible substrate 212 or web having a lithium film or lithium stacked film 214 formed thereon. During processing, the flexible substrate 212 is conveyed in the direction of travel indicated by arrow 126. In one embodiment, which can be combined with other embodiments, the lithium film or lithium stacked film 214 is a lithium metal film. In another embodiment, which can be combined with other embodiments, the lithium stacked film 214 includes a lithium metal film and an additional film, such as an anode film, such as a graphite film having a lithium metal film formed thereon.

[0035] Each lithium stack film 214 includes a lithium film and optional additional films. Although the lithium stack films 214 in Figures 2 and 3A-3C are shown as single layers on both sides of the flexible substrate 212, those skilled in the art will appreciate that the lithium stack films 214 can include more or fewer layers, which may be located above, below, and / or between the flexible substrate 212 and the lithium metal film 214. Although shown as a double-sided structure, those skilled in the art will appreciate that the flexible stack 210 may also be a single-sided structure with the flexible substrate 212 and lithium stack films 214.

[0036] The flexible laminate 140 may be disposed on a source roll 120. The flexible laminate 140 may be fed into the cutting system 100. A laser beam 130 removes a portion of one or more lithium films 214 from a flexible substrate 212 to create at least one blade cut zone 216 of width “L” between two or more portions 214 a, 214 b of each of the one or more lithium films 214. The at least one blade cut zone 216 is illustrated in FIG. 2 as being located along the longitudinal centerline of the flexible laminate 140, but may be located at any desired location on the flexible laminate 140, such as one-third of the width of the flexible laminate 140 from the edge of the laminate. The width “L” should be greater than the width of the blade 118, such as about 5 mm, about 3 mm, about 1 mm, or about 0.1 mm. After laser ablation at laser 130, flexible laminate 140 is subjected to blade cutting at blade 118. Blade 118 may be a fixed blade, a rotating blade, a reciprocating blade, or any suitable mechanical cutting device. Blade 118 cuts flexible substrate 212 in at least one blade cutting zone 216. Preferably, blade 118 cuts flexible substrate 212 on the centerline of blade cutting zone 216. The blade cutting results in two or more slit cutting rolls 122, such as first slit cutting roll 122a and second slit cutting roll 122b.

[0037] Figure 3A shows a cross-sectional side view of the flexible laminate 140 of Figure 2 prior to laser ablation and blade cutting in accordance with one or more embodiments of the present disclosure. The flexible laminate 140 in this embodiment comprises two of the one or more lithium films 214 on the top and bottom of the flexible substrate 212. While two lithium film layers are shown in Figure 3A, other amounts of layers are contemplated, such as one film layer on the top or bottom of the flexible substrate.

[0038] 3B shows a cross-sectional side view of the flexible laminate 140 of FIG. 2 after a laser ablation process and before a blade cutting process in accordance with one or more embodiments of the present disclosure. As shown in FIG. 3B, a portion of each of the one or more lithium films 214 has been removed from the surface of the flexible substrate 212, forming a blade cutting zone 216 in each of the one or more lithium films 214. The blade cutting zone 216 separates portion 214a from portion 214b by a width "L."

[0039] Figure 3C shows a cross-sectional view of the flexible laminate 140 of Figure 2 after the laser ablation and blade cutting processes. The blade 118 slit-cuts the flexible substrate 212 into two substrate portions 212a and 212b, which are rolled onto the first slit-cut roll 122a and the second slit-cut roll 122b.

[0040] Selection of laser parameters, such as pulse width, can be crucial to developing a successful laser and blade combination cutting process that achieves clean laser scribe cuts while minimizing damage to the underlying substrate during laser ablation. High-frequency nanosecond-pulsed IR lasers or picosecond-pulsed IR lasers can be used based on the unique laser-material interaction in lithium material stacks. Lithium is quite unique in that it has a melting point of only 453.65 K (180.50 °C) but still a very high boiling point of 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). The optical properties of lithium are largely unusable. For conductive substrates such as copper, IR laser absorption is much lower than that of green (approximately 520–540 ns) or UV lasers (<360 nm). For example, at room temperature, a 1064 nanometer laser has less than 5% optical absorption in copper, while a 532 nanometer green laser has about 40% optical absorption in copper. In molten copper, the 1064 nanometer laser still has about 5% optical absorption. From the perspective of avoiding copper damage, a 1 μm IR laser wavelength is more advantageous than a green or UV laser wavelength. Furthermore, at the same average power level and for the same type of laser, an IR laser is more reliable and cost-effective.

[0041] Laser parameters can be selected with benefits and advantages, such as providing sufficiently high laser intensity to achieve lithium removal and minimize damage to the underlying substrate. Furthermore, parameters can be selected to provide meaningful process throughput for industrial applications with precisely controlled ablation width (e.g., kerf width) and depth. As discussed above, ultrashort pulse (USP) lasers (e.g., lasers with pulse lengths up to the femtosecond range), such as femtosecond or picosecond pulsed lasers, are well suited to providing such benefits. Such pulse width ranges for USP lasers can be 5 fs to 999 fs, preferably 10 fs to 999 fs, for femtosecond pulsed lasers, and 1 ps to 10 ps for picosecond pulsed lasers. With regard to USP, the shorter the pulse width, the higher the peak power and the smaller the thermal impact. This allows for better control of the removal rate. For example, a 10 fs pulse has 1000 times higher peak power than a 10 ps pulse with the same pulse energy. Therefore, the wavelength range is not critical as the ablation can be stopped at a precise depth to remove a specific amount or thickness of lithium without thermally damaging the underlying substrate.

[0042] However, nanosecond-pulse laser ablation is also preferred because pulses longer than tens of picoseconds begin to have more significant thermal effects. Furthermore, nanosecond-pulse lasers are more cost-effective, although certain wavelengths may offer better performance than others. For PET substrates, a wavelength range of 450 nm to 1600 nm, preferably 450 nm to 1550 nm, facilitates laser ablation of lithium with nanosecond pulses, as PET films are highly transparent to light. Wavelengths below 450 nm, preferably below 355 nm, result in scribing or cutting PET substrates beyond ablation of the overlying lithium layer. For polyimide (PI) substrates, a wavelength range of 700 nm to 1700 nm, preferably 750 nm to 1600 nm, provides laser ablation of lithium with nanosecond pulses. Similarly, wavelengths below 450 nm result in scribing or cutting PI substrates beyond ablation of the overlying lithium layer.

[0043] The nanosecond pulses may range from 1 ns to 200 ns, preferably from 1 ns to 50 ns, preferably from 1 ns to 10 ns. For example, in one embodiment, a nanosecond pulsed laser process having a wavelength closer to or within the IR range provides a cleaner ablation process than a nanosecond pulsed laser process having a wavelength closer to or within the UV range. In certain such embodiments, femtosecond pulsed laser processes suitable for scribing semiconductor wafers or substrates are based on lasers having wavelengths of approximately 1 micrometer or greater. In certain such embodiments, pulses of approximately 15 nanoseconds or less of a laser having a wavelength of approximately 1 micrometer or greater are used. However, in alternative embodiments, two laser wavelengths (e.g., a combination of an IR laser and a UV laser) can be used.

[0044] In an alternative embodiment, laser ablation by laser beam 130 may not completely remove lithium from at least one blade cut zone 216. In doing so, the lithium film 214 is significantly reduced in at least one blade cut zone 216, preventing damage to the underlying roll surface while still providing the benefits of the present disclosure. In another alternative embodiment, laser ablation by laser beam 130 occurs outside of the roll area or at a specific angle of incidence determined by the optical properties of flexible substrate 212.

[0045] The embodiments and all functional operations described herein can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structural means disclosed herein and their structural equivalents, or in combinations of these. The embodiments described herein can also be implemented as one or more non-transitory computer program products, i.e., one or more computer programs tangibly embodied in a machine-readable storage device for execution by or control the operation of a data processing device, such as a programmable processor, a computer, or multiple processors or computers.

[0046] The processes and logic flows described herein may be performed by one or more programmable processors executing one or more computer programs to perform functions by manipulating input data and generating output. The processes and logic flows may also be performed by, and apparatus may be implemented as, special purpose logic circuitry, such as, for example, an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit).

[0047] The term "data processing device" encompasses any device, apparatus, and machine for processing data, such as, for example, a programmable processor, a computer, or multiple processors or computers. In addition to hardware, a device may include code that creates an execution environment for a given computer program, such as, for example, code comprising processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of these. Processors suitable for the execution of computer programs include, for example, both general-purpose and special-purpose microprocessors, and any one or more processors of any kind of digital computer.

[0048] Computer-readable media suitable for storing computer program instructions and data include, for example, all forms of non-volatile memory, media, and memory devices, such as 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 the memory may be supplemented by, or incorporated in, special purpose logic circuitry.

[0049] 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 element.

[0050] The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0051] While the foregoing is directed to several embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof, which scope is determined by the following claims.

Claims

1. 1. A system for slit cutting a flexible laminate, comprising: a laser source configured to generate a laser beam; Optical scanners, and a blade assembly positioned downstream of the laser beam; A slit cutting system comprising:

2. The slit cutting 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 onto the flexible stack.

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

5. The system of claim 1 , wherein the laser beam is configured to avoid damaging a flexible substrate layer of the flexible laminate.

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

7. 6. 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 slit cutting system of claim 1 , wherein the blade assembly comprises a blade and a blade stage.

9. The slit cutting system of claim 1 , wherein the blade assembly comprises a fixed blade.

10. a laser unit, and a blade disposed downstream of the laser unit; A slit cutting device comprising: The laser unit Optical assemblies, 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 slit cutting device comprising:

11. The slit cutting device of claim 10, wherein the laser source is a solid state laser configured to generate a continuous laser beam.

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

13. The slit cutting device of claim 10 , wherein the laser source is configured to generate a laser beam capable of ablating a coating on a flexible laminate.

14. The slit cutting device of claim 13 , wherein the laser source is further configured to avoid damaging a flexible substrate of the flexible laminate.

15. 1. A method for slitting a coated substrate, comprising: providing a coated substrate comprising at least one coating layer and a substrate layer to a laser unit; removing a portion of the at least one coating layer from the substrate layer of the coated substrate to expose a blade cutting area on the coated substrate; thereafter, feeding the coated substrate to a blade assembly; and slitting the coated substrate with the blade assembly within the blade cutting region; A method comprising:

16. The laser unit includes: Optical assemblies, a laser source coupled to the optical assembly; an optical bench positioned opposite the optical assembly; and a controller coupled to the optical assembly The method of claim 15, comprising:

17. The method of claim 15 , wherein the coating layer comprises lithium.

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

19. 16. 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. 16. The method of claim 15, wherein the blade cutting region is at least one longitudinal portion of the coated substrate configured to produce at least two slit-cut coated substrates.

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