Web Edge Measurement Method

Abstract

A metrology system and process are provided for continuous lithium ion battery (LIB) anode prelithiation and protection of solid metal anodes. In some embodiments, the metrology system integrates at least one complementary non-contact sensor that measures at least one of surface composition, coating thickness, and nanoscale roughness. The metrology system and process can be used to address anode edge quality. The metrology system and process can facilitate high quality and high yield closed-loop anode prelithiation and anode protection layer deposition, staged control of alloy-type anode prelithiation improves LIB coulombic efficiency, and pinhole-free anode coating and electrochemically active protection layer prevent dendrite formation.

Description

[Technical field]

[0001]

[0001] The embodiments described herein generally relate to vacuum deposition systems and methods for processing flexible substrates. In particular, the embodiments described and illustrated herein relate to roll-to-roll vacuum deposition systems and methods for monitoring and controlling the deposition of materials. [Background technology]

[0002]

[0002] Rechargeable electrochemical energy storage systems are gaining importance in many areas of daily life. High-capacity energy storage devices, such as lithium-ion (Li-ion) batteries and capacitors, are increasingly being used in many 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, the time and capacity of the energy storage device to charge and discharge 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 smaller the constraints the energy storage device faces in delivering electrical energy. For example, in the case of a battery, the internal resistance affects performance by reducing the total amount of useful energy that the battery stores and reducing the battery's ability to deliver high currents.

[0003]

[0003] An effective roll-to-roll deposition process not only provides a high deposition rate, but also provides a film surface that is free of small-scale roughness, contains minimal defects, and is flat, e.g., lacks large-scale topography. In addition, an effective roll-to-roll deposition process also provides consistent deposition results or "repeatable." Depositing a web material onto a substrate without controlling it and aligning or properly registering it with respect to the deposition source can adversely affect the process results and the internal resistance of the final battery.

[0004]

[0004] Therefore, there is a need for improved apparatus and methods for monitoring and controlling material deposition in roll-to-roll polishing systems. Summary of the Invention

[0005]

[0005] The embodiments described herein generally relate to vacuum deposition systems and methods for processing flexible substrates. In particular, the embodiments described and illustrated herein relate to roll-to-roll vacuum deposition systems and methods for monitoring and controlling material deposition.

[0006]

[0006] In one or more embodiments, a flexible substrate coating system is provided that includes a processing module having a plurality of chambers arranged in sequence, each chamber configured to perform one or more processing operations on a continuous sheet of flexible material. The processing module further includes a coating drum capable of guiding the continuous sheet of flexible material along a direction of travel through the plurality of chambers, the chambers being arranged radially around the coating drum. The processing module further includes a metrology module. The metrology module includes a plurality of non-contact sensors positioned side-by-side along a lateral direction perpendicular to the direction of travel.

[0007] In another embodiment, the plurality of non-contact sensors includes a spectroscopic sensor assembly operable to capture spectroscopic images of the coated and uncoated portions of the continuous sheet of flexible material. The spectroscopic sensor includes a strobe light source and an imager. The imager is a charge-coupled device (CCD) array. The plurality of non-contact sensors includes a first eddy current sensor operable to measure a thickness of the coated portion of the continuous sheet of flexible material and a second eddy current sensor operable to measure a thickness of the uncoated portion of the continuous sheet of flexible material. The coating system further includes an optical profilometer operable to measure a web roughness of the continuous sheet of flexible material. The plurality of non-contact sensors includes a web roughness sensor operable to measure a surface roughness of the coated portion of the continuous sheet of flexible material and the uncoated portion of the continuous sheet of flexible material. The web roughness sensor includes an argon laser and a CMOS camera. The coating system further includes a payout module housing a feed reel capable of providing a continuous sheet of flexible material, and a take-up module housing a return reel capable of storing the continuous sheet of flexible material. The continuous sheet of flexible material includes a copper substrate having a lithium metal layer formed thereon. The continuous sheet of flexible material includes a copper substrate having a lithiated anode film formed thereon. The anode film is selected from a graphite anode film, a silicon-graphite anode film, or a silicon film. The multiple chambers include at least one of a sputtering source, a thermal evaporation source, and an electron beam source.

[0008] In some embodiments, the method includes conveying the continuous sheet of flexible material from a feed reel in the outfeed chamber to a deposition module disposed downstream of the outfeed chamber, the deposition module including a first coating drum capable of guiding the continuous sheet of flexible material through a plurality of deposition units. The method further includes guiding the continuous sheet of flexible material through the plurality of deposition units along an advancing direction while depositing a lithium metal film on the flexible substrate through the first plurality of deposition units, the chambers being radially disposed around the coating drum. The method further includes guiding the continuous sheet of flexible material through a metrology module including a plurality of non-contact optical sensors positioned side-by-side along a lateral direction, the optical sensors having a field of view that coincides with a path of travel along which the continuous sheet of flexible material travels, the lateral direction being perpendicular to the advancing direction. The method further includes flashing a strobe lamp within the field of view while guiding the continuous sheet of flexible material through the field of view. The method further includes acquiring a still image of the continuous sheet of flexible material within the field of view. The method further includes channeling light reflected from each image element of the image through a respective light channeling element to a respective location of the spectral light distributor. The method further includes recording a spectral distribution at each image element within the field of view.

[0009]

[0009] In one or more embodiments, the method further includes searching for distributions that are similar to each other and grouping the distributions into groups of mutually similar distributions. The method further includes sorting the groups by the number of distributions contained in each group. The method further includes selecting at least one of the largest groups and combining the distributions of that group together and providing the combined distribution as a spectral distribution of a region of a continuous sheet of flexible material. The method further includes processing the combined distribution according to a spectral analysis process. The continuous sheet of flexible material includes a copper substrate, and a lithium metal film is formed on the copper substrate. The continuous sheet of flexible material includes a copper substrate having an anode film formed thereon, and a lithium metal film is formed on the anode film. The anode film is selected from a graphite anode film, a silicon-graphite anode film, or a silicon film.

[0010] In another embodiment, the method includes conveying the continuous sheet of flexible material from a feed reel in the outfeed chamber to a deposition module disposed downstream of the outfeed chamber, the deposition module including a first coating drum capable of guiding the continuous sheet of flexible material through a plurality of deposition units. The method further includes guiding the continuous sheet of flexible material through the plurality of deposition units along an advancing direction while depositing a lithium metal film on the flexible substrate through the first plurality of deposition units, the chambers being radially disposed around the coating drum. The method further includes guiding the continuous sheet of flexible material through a metrology module, the metrology module including a plurality of non-contact optical sensors positioned side-by-side along a lateral direction. The optical sensors have a field of view that coincides with a path of travel along which the continuous sheet of flexible material travels, the lateral direction being perpendicular to the advancing direction. The method further includes obtaining a first non-contact electrical resistance measurement of the lithium metal film on the continuous sheet of flexible material within the field of view. The method further includes determining a first thickness of the lithium metal film using the first non-contact electrical resistance measurement.

[0011]

[0011] Embodiments may include one or more of the following possible advantages: Determining the first thickness of the lithium metal film includes comparing the first non-contact electrical resistance measurement to a previously determined correlation between the electrical resistance measurements and respective thicknesses of the lithium metal film. The method further includes obtaining a non-contact laser interferometry measurement of the continuous sheet of flexible material within the field of view. The method further includes determining a web roughness of the continuous sheet of flexible material based on the non-contact laser interferometry measurement of the continuous sheet of flexible material. The method further includes adjusting the first thickness measurement of the lithium metal film based on the web roughness to determine a modified first thickness of the lithium metal film. The method further includes aging the lithium metal film for a period of time. The method further includes obtaining a second non-contact electrical resistance measurement of the lithium metal film on the continuous sheet of flexible material within the field of view after aging the lithium metal film for a period of time. The method further includes using the second non-contact electrical resistance measurement to determine a second thickness of the lithium metal film. Determining the second thickness of the lithium metal film includes comparing the second non-contact electrical resistance measurement to a previously determined correlation between the electrical resistance measurements and the respective thicknesses of the lithium metal films. The method further includes determining an amount of pre-lithiation of the anode film deposited on the continuous sheet of flexible material by comparing the first thickness of the lithium metal film to the second thickness of the lithium metal film. The continuous sheet of flexible material includes a copper substrate, and the lithium metal film is formed on the copper substrate. The continuous sheet of flexible material includes a copper substrate on which the anode film is formed, and the lithium metal film is formed on the anode film. The anode film is selected from a graphite anode film, a silicon-graphite anode film, or a silicon film.

[0012] In some embodiments, the method includes conveying the continuous sheet of flexible material from a feed reel in a delivery chamber to a deposition module disposed downstream of the delivery chamber, the deposition module including a first coating drum capable of guiding the continuous sheet of flexible material through a plurality of deposition units. The method further includes guiding the continuous sheet of flexible material through the plurality of deposition units along a traveling direction while depositing a lithium metal film on the flexible substrate through the first plurality of deposition units, the chambers being radially disposed around the coating drum. The method further includes guiding the continuous sheet of flexible material through a metrology module including a plurality of non-contact optical sensors positioned side-by-side along a lateral direction, the optical sensors having a field of view that coincides with a traveling path along which the continuous sheet of flexible material travels, the lateral direction being perpendicular to the traveling direction. The method further includes projecting three or more fringe patterns of polarized structured light onto the continuous sheet of flexible material within the field of view. The method further includes recording the intensity at each image element within the field of view for each fringe shift. The method further includes determining a measure of coating roughness from the distribution of intensities of the image elements.

[0013] In another embodiment, a non-transitory computer-readable medium stores instructions that, when executed by a processor, cause a process to perform the operations of the apparatus and / or method described above. [Brief description of the drawings]

[0014] So that the above-mentioned features of the present disclosure can be understood in detail, a more particular description of the above briefly summarized embodiments will be obtained by reference to the embodiments, some of which are illustrated in the accompanying drawings, which should be noted, however, that the present disclosure is open to other equally effective embodiments, and therefore, the accompanying drawings only illustrate typical embodiments of the present disclosure, and should not be considered as limiting the scope of the present disclosure.

[0015] [Figure 1]1 is a schematic cross-sectional view of one example of a flexible layer stack formed according to one or more embodiments described herein. [Diagram 2]

[0016] 2 is a schematic cross-sectional view of another example of a flexible layer stack formed in accordance with one or more embodiments described herein. [Diagram 3]

[0017] 1 is a schematic side view of a vacuum processing system incorporating metrology according to one or more embodiments described and illustrated herein. [Figure 4]

[0018] 4 is a schematic diagram of a portion of the vacuum processing system of FIG. 3 according to one or more embodiments described and illustrated herein. [Diagram 5]

[0019] 1 illustrates a spectroscopic measurement system according to one or more embodiments described and illustrated herein. [Figure 6]

[0020] FIG. 1 is a flow diagram of a process according to one or more embodiments described and illustrated herein. [Figure 7]

[0021] 1 illustrates an eddy current sensor (ECS) metrology system according to one or more embodiments described and illustrated herein. [Figure 8]

[0022] FIG. 1 is a flow diagram of a process according to one or more embodiments described and illustrated herein. [Figure 9]

[0023] 1 illustrates a roughness sensor metrology system according to one or more embodiments described and illustrated herein. [Figure 10]

[0024] FIG. 1 is a flow diagram of a process according to one or more embodiments described and illustrated herein.

[0016]

[0025] To facilitate understanding, wherever possible, the same reference numerals have been used to designate identical elements 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 OF THE PREFERRED EMBODIMENTS

[0017]

[0026] The following disclosure describes a roll-to-roll vacuum deposition system, a metrology system, and a method for forming at least two layers on a flexible substrate. Specific details are set forth in the following description and in Figures 1-10 to provide a thorough understanding of various embodiments of the present disclosure. Other details describing well-known structures and systems often associated with web coating, coating metrology systems, electrochemical cells, and secondary batteries are not set forth in the following disclosure to avoid unnecessarily obscuring the description of the various embodiments.

[0018]

[0027] Many of the details, dimensions, angles, and other features shown in the drawings are merely illustrative of particular embodiments. Thus, other embodiments can have other details, components, dimensions, angles, and features without departing from the spirit or scope of the present disclosure. In addition, further embodiments of the present disclosure can be practiced without some of the details described below.

[0019]

[0028] Energy storage devices, such as batteries, generally include a positive electrode, an anode electrode separated by a porous separator, and an electrolyte used as an ion-conducting matrix. Graphite anodes are the current state of the art, but the industry is moving away from graphite-based anodes to silicon-mixed graphite anodes to increase the energy density of the cells. However, silicon-mixed graphite anodes often suffer from irreversible capacity loss during the first cycle. Thus, a method is needed to replenish this first cycle capacity loss. In addition, lithium metal anodes are also envisioned. However, lithium metal anodes present a number of safety concerns.

[0020]

[0029] Vacuum web coatings for prelithiation of anodes and protection of solid metal anodes include thick (3 to 20 microns) lithium metal depositions on double-sided coated, calendared graphite anodes and current collectors, e.g., 6 micron or thicker copper foil, nickel foil, or metallized plastic webs. Web coatings for prelithiation and solid metal anodes further include a thin, e.g., less than 1 micron, protective layer coating. In the absence of a protective layer coating, the lithium metal (either thermally evaporated or rolled foil) surface is susceptible to deleterious corrosion and oxidation.

[0021]

[0030] In some embodiments, metrology systems and process methods are provided for prelithiation of continuous lithium ion battery ("LIB") electric vehicle ("EV") anodes and protection of consumer electronics ("CE") solid metal anodes. In some embodiments, the metrology system incorporates at least one complementary non-contact sensor that measures at least one of surface composition, coating thickness, and nanoscale roughness. The metrology systems and process methods can be used to address anode edge quality. The metrology systems and methods can facilitate high quality and high yield closed loop anode prelithiation and deposition of anode protection layers, staged control of EV alloy-type anode prelithiation improves LIB coulombic efficiency, and pinhole-free CE anode coatings and electrochemically active protection layers suppress dendrite formation.

[0022]

[0031] Web coatings for prelithiation of EV anodes and CE solid metal anode protection generally comprise a thick, e.g., 3 to 20 micron, lithium metal deposition on a double-sided coated, calendared graphite anode and current collector, e.g., 6 micron or thicker copper foil, nickel foil, or metallized plastic web. EV and CE anode web coatings generally further comprise a thin (<1 micron) protective layer coating.

[0023]

[0032] Thin protective layers that are coated onto reactive metallic lithium coatings are generally difficult to characterize using traditional radioisotope web metrology, which generally relies on changes in base density and is therefore relatively insensitive to thin lithium films. For example, the sensitivity of the Krypton-85 radioisotope source is 25 g / m 2 However, a 20 micron thick lithium coating weighs just 11 g / m 2 Moreover, metallic lithium and protective layer web coatings are difficult to characterize using conventional thin film quartz crystal microbalances (QMBs), laser triangulation, e.g., Keyence and Micro-Epsilon LVDT interferometers, and capacitive, e.g., eddy current sensors (ECSs). In addition, conventional thin film sensors provide only a global baseline, and readings cannot be used to assess local (web edge) film composition, e.g., surface contamination, and are prone to noise due to unavoidable web roughness, typically caused by web winding vibrations.

[0024]

[0033] The local film composition of the anode edge near the cathode overhang is a factor that affects cell performance. For prismatic and jelly roll cells, the anode is typically larger than the cathode by approximately 0.5 millimeters on all sides or approximately 0.1 millimeters along the top and bottom. Furthermore, excess metallic lithium (from thermally evaporated metallic lithium for prelithiation) in this "overhang" area along one or more anode edges can pose a significant safety hazard and can adversely affect cell performance.

[0025]

[0034] In addition to producing an anode with 10 to 15 percent higher electrochemical capacity, the overhang (as small as 0.1 millimeters wide) is provided to avoid the risk of lithium ions migrating from the cathode to the anode during cell charging and plating along the edges of the current collector. Thus, the manufacture of lithium-ion batteries generally involves precise process control over the amount of metallic lithium and a final prelithiation stage control when the coating of the anode approaches within 0.5 to 0.1 millimeters of the edge of the overhang.

[0026]

[0035] One consequence of the need for precise metallic lithium coating prior to intercalation near the anode overhang area is that the protective layer requires a similarly high level of attention to edge quality. For example, an electrochemically insulating protective layer material, such as lithium carbonate, can be surface converted onto the as-deposited metallic lithium to minimize the air reactivity of the metallic lithium during cell assembly, and it is important to verify that the carbonate protective layer is not too thick. If the surface converted lithium carbonate is too thick, dead lithium, e.g., lithium compounds rather than metallic lithium, can be present near the overhang. Dead lithium is undesirable along the anode edge because it can introduce a dendritic hazard that negates the techno-economic incentive for prelithiation of the anode.

[0027]

[0036] When an electrochemically active protective layer material, such as lithium fluoride, is coated onto the as-deposited lithium metal to minimize contact resistance and improve electrolyte wetting, in addition to minimizing the air reactivity of the lithium metal during cell assembly, it is important to verify that the lithium fluoride protective layer is not too rough, which can result in pinholes, surface contamination of the underlying lithium metal, and other undesirable defects near the overhang.

[0028]

[0037] Thus, there is a need for a metrology system that can precisely measure the lithium metal and protective layer composition, thickness non-uniformity, and roughness. In the absence of the web edge metrology system described herein, expensive and undesirable trial and error would be required to optimize anode edge quality. In addition, a toll coating business strategy based on high coating loading anode designs would not be feasible given the need for costly destructive SEM cross section analysis and the inability to separate high quality coating lengths from "reworkable" lengths on each roll.

[0029]

[0038] Some embodiments described and illustrated herein improve upon conventional roll-to-roll ("R2R") metrology. As discussed above, radioisotope and other sensors have limited usefulness for characterizing alkali-metal patterned webs. However, aspects of some conventional sensors are useful, but certain limitations must be overcome.

[0030]

[0039] One such sensor is the Linear Variable Differential Transformer (LVDT) sensor. The LVDT sensor triangulates the time of flight between the laser source, the surface, and the receiver, and then correlates the time of flight with a calibrated coating thickness. In battery coating applications, the coating thickness and uniformity are typically adjusted in response to a calculated difference between the real-time web recipe set point and the LVDT thickness measurement.

[0031]

[0040] Unfortunately, LVDT deposition thickness control alone is insufficient for anode prelithiation, since LVDT sensors are not suitable for nanoscale roughness due to their low resolution, and are not suitable for detecting the presence of protective layers or surface contamination of nanoscale thickness. LVDT sensors are also not suitable for anode prelithiation, since metallic lithium coatings deposited on silicon anodes are known to become thinner as the metallic lithium coating intercalates into silicon and graphite, and therefore LVDT sensors alone are insufficient to characterize the prelithiated coating.

[0032]

[0041] Furthermore, for only the thickness of the metallic lithium layer, thickness control of the LVDT deposition is hindered by measurement noise due to inherent web roughness. The measurement noise can be numerically compensated for, but again, a key issue is edge characterization near the anode overhang, which is typically smaller than the spot size of many LVDT sensors, e.g., less than 0.5 mm.

[0033]

[0042] Some embodiments described and illustrated herein provide characterization of the web edge near the 0.5 millimeter overhang of the anode edge using the optical and capacitance-based metrology system of the present invention that also benefits from the numerically compensated thickness measurement of the LVDT.

[0034]

[0043] The embodiments described and illustrated herein may include one or more of the following advantages: Metallic lithium can be differentiated from lithium compounds, including protective layers and contamination. After metallic lithium and protective layer coatings are applied to the pre-lithiated anode and lithium metal anode, a discoloration is observable. Such visually observable discoloration was recognized by the inventors as an opportunity to further facilitate precise non-contact optical-based characterization using broadband spectrum, e.g., strobe lamps, and narrowband, e.g., laser light sources.

[0035]

[0044] Some cell designs, such as fast-charging EV LIBs, require more silicon and therefore more lithium than others, but excessive metallic lithium coating and overprotection near the web edges presents safety hazards and negates the techno-economic benefits of prelithiating the anode.

[0036]

[0045] The embodiments described and illustrated herein may further include one or more of the following advantages: Excess metallic lithium and dead lithium can be verified to be absent along the anode edges and overhangs of the EV anode. Furthermore, defects in the coating, e.g., insufficient metallic lithium thickness or insufficient protective layer thickness, can be detected and the web can be reworked in a second pass through the web coater to minimize scrap. In addition, the embodiments disclosed herein can be adapted for characterization of blanket coatings at the center of the web or other locations in the lateral and longitudinal directions. For example, spectroscopy can be used to detect lithium "splatters" on the anode if the spectroscopy module is adjusted to obtain the full lateral width of the web, e.g., the same number of CMOS pixels of field of view, but on a millimeter scale per pixel. Although the splatters generally cannot be reworked, the splatters and other defects can be mapped so that more of the remaining web can be manually salvaged, which is acceptable for some applications.

[0037]

[0046] For CE LIBs, some cell designs for CE applications without cost consideration use high purity and specialty materials that are not suitable for EV applications. The protective layer of the CE anode can be deposited using reactive chemistries, e.g., pyrophoric and toxic precursors, to produce a more sophisticated functional protective layer (sometimes multi-layered) than minimizing air reactivity alone. For such next generation protective layers under development, an advantage of the optical elements described and illustrated herein is the ability to discern surface composition and nanoscale roughness near the web edge (and overhang of the CE anode).

[0038]

[0047] For EV and CE LIBs, as described above, discoloration is observed in the lithium "sandwiched" between the substrate and the coating. In some embodiments, the optical elements of the metrology system are designed to detect such subtle discoloration. The inventors believe that the observable discoloration (including various shades of gray and white) is an important indicator of web, process and coater health. For example, the observable discoloration can be used to aid in anode development and manufacturing by quantifying the visible film transformation that occurs after coating, sometimes hours to days, just prior to cell assembly and aging.

[0039]

[0048] In some embodiments, a metrology system and process method for continuous lithium ion battery ("LIB") anode prelithiation and solid metal anode protection is provided. The metrology system includes various modules and methods.

[0040]

[0049] In some embodiments, the metrology system includes a spectroscopic metrology system for spectroscopic (real-time) analysis of roughness, surface contamination, and / or quality of the protective layer of the as-deposited lithium metal. The spectroscopic metrology system can include one or more broadband spectrum light sources. The broadband spectrum light source can be a light source that can measure area (e.g., circular > TIFF2024501446000002.tif617025mm or rectangle >25mm wide) used for specular and spectral analysis. Specular and spectral analysis can be focused along the web edge. The broadband spectrum light source can be constant or flashing, for example, if the anode has a start-stop intermittent coating.

[0041]

[0050] The spectroscopic measurement system can further include one or more image sensors that can be focused on the LIB anode in the area illuminated by the broad-spectrum light source to detect reflected emission light.

[0042]

[0051] The spectroscopic metrology system may further include an image sensor signal processor. The image sensor signal processor converts the specular reflection intensity into a calibrated reflectance value. For example, a high reflectance may indicate a "mirror-like" metallic lithium end, and a low reflectance may indicate a "dull" metallic lithium end. A "mirror-like" metallic lithium end may be characteristic of a desired high metallic lithium purity without the presence of undesirable surface contamination above the metallic lithium. A lower surface roughness may be characteristic of a desired high metallic lithium deposit quality without the presence of small lithium ion cluster condensation and undesirable "splash" or "remelt" of lithium. The image sensor element may also be used to detect edge dimension variations, such as average straightness. Image sensor signal processing may be used to convert the spectral emission signature into a calibrated protective layer composition. One or more wavelengths of reflected light that fall outside of the established spectral process control range specific to the material may indicate a detrimental protective layer process outage. The metrology system feedback to the controller may be used to adjust deposition parameters. For example, if a low reflectance value is detected, the controller may record a contamination fault. A contamination failure may be due to a vacuum air leak, an anode outgassing, or any other oxygen, hydrogen, or nitrogen source ("OHN"). The metrology system feedback allows the operator to stop or adjust the metallic lithium deposition process to minimize waste. If the spectral peaks have a different intensity, e.g., the intensity peaks are below a minimum threshold or occur at different wavelengths, e.g., the peaks "shift" below a minimum wavelength or above a maximum wavelength, the controller records a protective layer failure. A protective layer failure may be due to depletion of the protective layer material source, e.g., a gas or solid source is depleted, deposition on contaminated metallic lithium, deposition on non-uniform (large lithium clusters) metallic lithium, or any other deviation in the process window of the protective layer deposition. The metrology system feedback allows the operator to adjust or terminate the protective layer deposition process to minimize scrap.The spectroscopic metrology described herein can be used to monitor the mirror finish and discoloration of the composite spectrogram, and further develop material-specific waveform libraries for use in making process adjustments or termination decisions.

[0043]

[0052] In some embodiments, the metrology system includes an eddy current sensor (ECS) based metrology system for monitoring the thickness of the as-deposited coating and the application of the protective layer. The metrology system may further include a displacement sensor. The metrology system may include a sensor structure including at least a pair of eddy current sensors and a displacement sensor. The displacement sensor may be a linear variable differential transformer (LVDT) profilometer thickness sensor. The sensor structure may be positioned within the coating system to monitor the as-deposited metallic lithium and the protective layer coating to determine the thickness gain of the metallic lithium. A signal from an ECS positioned over an uncoated portion of the web, e.g., bare copper, is offset or subtracted from an ECS signal of a capacitive sensor positioned over a coated anode portion of the web. In this way, the capacitance of only the anode coating (not including the copper foil) is taken into account. The signal may be further corrected for web roughness using the lift-off distance measured by the LVDT profilometer. The micron-scale thickness of the as-deposited metallic lithium reservoir may be measured in the cross-web direction by positioning the sensor across the width of the web. Any suitable number of sensors may be used depending on the measurements desired. For example, for each deposition source, a pair of eddy current and LVDT thickness sensors may be positioned in front of and behind the deposition source to provide measurements of the lithium metal thickness gain in the cross-web direction. In one embodiment, if there are three deposition sources, a pair of eddy current and LVDT thickness sensors may be positioned in front of and behind the deposition source for a total of six sensors to provide three measurements of the lithium metal thickness gain in the cross-web direction.

[0044]

[0053] The micron-scale depletion of the as-deposited metallic lithium reservoir thickness can be measured across the web after prelithiation at a given temperature in an environment favorable for lithium ion interaction. Measuring the micron-scale depletion of the metallic lithium reservoir thickness helps determine when to deposit the next protective layer. One advantage of applying a protective layer before or after the prelithiation conditioning and micron-scale depletion of the reservoir thickness is that the possibility of dead lithium generation is minimized. Due to the slow process of metallic lithium intercalation into the anode, application of a protective layer prior to metallic lithium intercalation can trap metallic lithium on the surface. Therefore, it is preferred to apply a protective layer after the metallic lithium reservoir is stabilized and intercalated into the anode in a controlled manner.

[0045]

[0054] In some embodiments, the metrology system includes a polarized structured light (PSL) generator and an image sensor. The PSL generator and image sensor can be configured to monitor edge finish of the metallic lithium. The metrology system includes a sensor structure including a PSL generator and an image sensor. The sensor structure can be centered on one or more edges of the anode. The sensor structure can be positioned behind the metallic lithium source and the protective layer coating source. The PSL generator can project a narrow band of light onto the three-dimensional anode edge. The coating near the three-dimensional anode edge typically has an inherent nanoscale roughness that scatters and depolarizes the reflected polarized light. The scattered and depolarized light is recorded by the image sensor. The contrast between the two reference waves and the emission from the anode is used to calculate the roughness, which is proportional to the polarized light source. In one example, the polarized light source can be a laser source, for example, a 488 nanometer laser source.

[0046]

[0055] The geometry of the as-deposited metallic lithium at the proximal and distal ends is recorded continuously or intermittently along the web length. Structured light can complement conventional laser profilometers by narrowing the field of view to the edge (inside or outside the graphite step for prelithiated anodes and inside or outside the lithium-only step for lithium metal anodes). Examples of laser profilometers that can be used with the embodiments described herein include the Keyence LJ-X8020, which can measure anode edge finish to within 7.5 mm wide and has repeatability of edge thickness (Z-axis) and straightness (X-axis) to within 0.3 μm for both axes, and the Keyence CL-PT010, which can measure anode edge finish to within 10 mm wide and has repeatability of edge thickness and straightness to within 0.2 μm for both axes. Polarized structured light enhances the view by providing the benefits of drum wobble-compensated thickness measurements determined using a conventional profilometer and nanoscale roughness inside and outside the coating area near the anode overhang.

[0047]

[0056] For pre-lithiated anodes, if the metallic lithium is outside of the slurry casting anode coating, the controller will record a coating failure. If the sensing spot is centered on roll annealed (RA) or electrodeposited (ED) copper, metallic lithium outside of the slurry casting anode can be detected. For lithium metal anodes, if the metallic lithium is outside of the preferred coating boundary, the controller can record a coating failure and terminate the process. Because it can be difficult to rework or remove the metallic lithium coating outside of the preferred coating footprint, the controller can record a coating failure to facilitate salvage of the portion of the web that meets the coating specifications.

[0048]

[0057] For prelithiated and lithium metal anodes, if the quality of the metallic lithium inside the desired coating boundary is too thin and / or too rough, the controller can record the coating failure and adjust the coating recipe. In most PVD systems, edge finish is controlled using a conventional (heated) temperature-controlled mask liner. However, if the mask liner is too hot, the direct radiation to the edge will exceed the optimum and the metallic lithium coating may remelt, decreasing the overall thickness while increasing the surface roughness. Thus, if the PSL and profilometer indicate high edge roughness or edge thinning, the temperature-controlled mask can be actively fluid-cooled or the heater power can be adjusted to proportionally reduce the temperature of the mask.

[0049]

[0058] For pre-lithiated and lithium metal anodes, if the metallic lithium thickness is too thin and smooth, the controller will record a coating failure and attempt to adjust the coating recipe. In most PVD systems, the coating thickness is determined by the vapor source temperature, web speed, and web gap pressure. If the web speed is too high or the vapor source temperature is too low, the coating may be too thin. Thus, if the PSL and profilometer indicate low edge roughness due to edge thinning, the vapor power can be increased and / or the web speed can be decreased.

[0050]

[0059] While there is no limitation on the particular substrate on which some of the embodiments described herein may be practiced, it is noted that it is particularly useful to practice the embodiments on flexible substrates, including, for example, web-based substrates, panels, and discrete sheets. The substrate may also be in the form of a foil, film, or sheet.

[0051]

[0060] It should also be noted that the flexible substrates or webs used within the embodiments described herein can generally be characterized in that they are bendable. The term "web" can be used synonymously with the term "strip" or the term "flexible substrate." For example, the webs described within the embodiments herein can be foils.

[0052]

[0061] It is further noted that in some embodiments where the substrate is a vertically oriented substrate, the vertically oriented substrate can be angled with respect to the vertical plane. For example, in some embodiments, the substrate can be angled between about 1 degree and about 20 degrees from the vertical plane. In some embodiments where the substrate is a horizontally oriented substrate, the horizontally oriented substrate can be angled with respect to the horizontal plane. For example, in some embodiments, the substrate can be angled between about 1 degree and about 20 degrees from the horizontal plane. As used herein, the term "vertical" is defined as the major surface or deposition surface of the flexible conductive substrate being perpendicular to the horizontal. As used herein, the term "horizontal" is defined as the major surface or deposition surface of the flexible conductive substrate being parallel to the horizontal.

[0053]

[0062] It is further noted that in the present 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 while the substrate is in a processing system. At least some of the "rolls" or "rollers" referred to herein can include a circular-like 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 can be formed about a curved longitudinal axis. According to some embodiments, the "rolls" or "rollers" described herein can be adapted to contact a flexible substrate. For example, the "rolls" or "rollers" referred to herein can be guide rollers adapted to guide the substrate while it is being processed (e.g. during a deposition process) or while it is in the processing system, spreader rollers adapted to provide a defined tension to the substrate to be coated, deflection rollers for deflecting the substrate according to a defined path of movement, processing rollers for supporting the substrate during processing, processing drums such as coating rollers or coating drums, adjustment rollers, supply rolls, or recovery rolls, etc. The "rolls" or "rollers" described herein can include metal. In one or more embodiments, the surface of the roller device that contacts the substrate can be adapted for each substrate to be coated. Furthermore, it should be understood that according to some embodiments, the rollers described herein can be mounted on low friction roller bearings, in particular having a dual bearing roller architecture. Thus, the parallelism of the rollers of the transport apparatus described herein can be achieved and lateral substrate "rocking" can be eliminated during substrate transport.

[0054]

[0063] FIG. 1 is a schematic cross-sectional view of an example of a flexible layer stack 100 formed according to one or more embodiments described herein. The flexible layer stack 100 can be formed by a strip coating process. The flexible layer stack 100 can be formed using a metrology system described herein. The flexible layer stack 100 can be a lithium metal anode structure. The flexible layer stack 100 shown in FIG. 1 includes a continuous flexible substrate 110 on which a number of film stacks 112a-d (collectively 112) are formed. Each film stack 112a-d defines a strip that is separated from the strips formed by adjacent film stacks 112a-d. For example, the first film stack 112a defines a first strip of deposited material, the second film stack 112b defines a second strip of deposited material, the third film stack 112c defines a third strip of material, and the fourth film stack 112d defines a fourth strip of material. The pattern of film stacks 112a-d leaves an uncoated strip of the continuous flexible substrate 110 exposed along a proximal end 113 of the continuous flexible substrate 110, an uncoated strip along a distal end 117 of the continuous flexible substrate 110, and an uncoated strip 115 defined between the first strip of deposited material 112a and the second strip of deposited material 112b.

[0055]

[0064] Each film stack 112a-d includes a first layer 120a-d (collectively 120) and a second layer 130a-d. Although the flexible layer stack 100 shown in FIG. 1 has two layers on each side of the continuous flexible substrate 110, those skilled in the art will appreciate that the flexible layer stack 100 may include more or fewer layers that may be provided above, below, and / or between the continuous flexible substrate 110, the first layer 120, and / or the second layer 130 as shown in FIG. 1. Although shown as a double-sided structure, those skilled in the art will appreciate that the flexible layer stack 100 may also be a single-sided structure having a continuous flexible substrate 110, the first layer 120, and the second layer 130.

[0056]

[0065] According to some embodiments described herein, the continuous flexible substrate 110 can include a first material and / or the first layer 120 can include a second material. Additionally, the second layer 130 can include a third material. For example, the first material can be a conductive material, typically a metal such as copper (Cu) or nickel (Ni). Additionally, the continuous flexible substrate 110 can include one or more sub-layers. The second material can be a metal with a low melting temperature, for example an alkali metal such as lithium. The third material can be a protective film or slip-in film operable to protect the metal with a low melting temperature.

[0057]

[0066] Generally, in prismatic cells, the tab is formed of the same material as the current collector and may be formed during the manufacture of the stack or may be added later. In some embodiments, as shown in FIG. 1, the current collector extends beyond the film stack and the portion of the current collector that extends beyond the stack may be used as the tab. For example, the tab may be formed using any of the uncoated strip of the continuous flexible substrate 110 exposed along the proximal end 113 of the continuous flexible substrate 110, the uncoated strip along the distal end 117 of the continuous flexible substrate 110, and the uncoated strip 115 defined between the first film stack 112a and the second film stack 112b.

[0058]

[0067] According to some embodiments described herein, the continuous flexible substrate 110 can have a thickness of about 25 μm or less, typically 20 μm or less, specifically 15 μm or less, and / or typically 3 μm or more, specifically 5 μm or more. The continuous flexible substrate 110 can be thick enough to provide its intended function and thin enough to be flexible. Specifically, the continuous flexible substrate 110 can be as thin as possible such that the continuous flexible substrate 110 can still provide its intended function.

[0059]

[0068] According to some embodiments described herein, the first layer 120 can have a thickness of 10 μm or less, typically 8 μm or less, advantageously 7 μm or less, specifically 6 μm or less, and especially 5 μm or less. According to some embodiments, the thickness of the first layer 120 can be 4 μm or less, or 3 μm or less, or 2 μm or less.

[0060]

[0069] According to some embodiments described herein, the second layer 130 can have a thickness of 10 μm or less, typically 8 μm or less, advantageously 7 μm or less, specifically 6 μm or less, and especially 5 μm or less. According to some embodiments, the thickness of the second layer 130 can be 4 μm or less, or 3 μm or less, or 2 μm or less.

[0061]

[0070] The flexible layer stack 100 shown in Fig. 1 can be, for example, a negative electrode of / for a secondary battery, for example, a negative electrode or anode of / for a lithium battery. According to some embodiments described herein, the flexible negative electrode for a lithium battery can be a continuous flexible substrate 110, which can be a current collector comprising copper and having a thickness of 10 μm or less, typically 8 μm or less, advantageously 7 μm or less, particularly 6 μm or less, in particular 5 μm or less. The flexible negative electrode further comprises a first layer 120 comprising lithium and having a thickness of 5 μm or more and / or 15 μm or less, and a second layer 130 comprising a protective film having a thickness of 5 μm or more and / or 15 μm or less.

[0062]

[0071] FIG. 2 is a schematic cross-sectional view of another example of a flexible layer stack 200 formed according to one or more embodiments described herein. The flexible layer stack 200 is similar to the flexible layer stack 100 shown in FIG. 1. The flexible layer stack 200 can be formed by a strip coating process. The flexible layer stack 200 can be formed using a metrology system described herein. The flexible layer stack 200 can be a pre-lithiated anode structure. The flexible layer stack 200 shown in FIG. 2 includes a continuous flexible substrate 110 on which a plurality of film stacks 212a-d (collectively 212) are formed. Each film stack 212a-d defines a strip, which is separated from the strips formed by adjacent film stacks 212a-d. Each film stack 212a-d further includes a third layer 210a-d (collectively 210) sandwiched between the continuous flexible substrate 110 and the first layer 120. The third layer 210 can include a fourth material. The third layer 210 can have a thickness of about 10 μm to about 200 μm (e.g., about 1 μm to about 100 μm, about 10 μm to about 30 μm, about 20 μm to about 30 μm, about 1 μm to about 20 μm, or about 50 μm to about 100 μm). The fourth material can include an anode material composed of graphite, silicon, silicon-containing graphite, lithium metal, lithium metal foil or lithium alloy foil (e.g., lithium aluminum alloy), or a mixture of lithium metal and / or lithium alloy with materials such as carbon (e.g., coke, graphite), nickel, copper, tin, indium, silicon, oxides thereof, or combinations thereof. The fourth material may further include a binder material. For example, the first material may be a conductive material, typically a metal such as copper (Cu) or nickel (Ni). The fourth material may be graphite, silicon, or silicon-containing graphite. The third material may be a metal with a low melting temperature, for example an alkali metal such as lithium. The third material may be a protective interleaving film operable to protect the metal with a low melting temperature.

[0063]

[0072] 3 is a schematic side view of a flexible substrate coating system incorporating one or more metrology modules according to one or more embodiments described and illustrated herein. The flexible substrate coating system 300 includes a first metrology module 370 and an optional second metrology module 380. The first metrology module 370 can be at least one of a spectroscopic metrology module, a capacitance-based metrology module, or a thickness metrology module. The second metrology module 380 can be at least one of a spectroscopic metrology module, a capacitance-based metrology module, or a thickness metrology module. In one embodiment, the first metrology module 370 is a thickness metrology module and the second metrology module 380 is a spectroscopic metrology module. The thickness metrology module can be configured to measure the thickness of the deposited material on the successive flexible substrates. The spectroscopic metrology module can be configured to measure at least one of a surface roughness, a surface contamination, and a quality of a protective layer.

[0064]

[0073] The flexible substrate coating system 300 can be a SMARTWEB® system manufactured by Applied Materials adapted for manufacturing lithium-containing anode film stacks according to embodiments described herein. The flexible substrate coating system 300 can be used for manufacturing lithium-containing anodes, particularly for film stacks for lithium-containing anodes, such as the flexible layer stack 100 and the flexible layer stack 200. The flexible substrate coating system 300 includes a common processing environment 301 in which some or all of the processing operations for manufacturing the lithium-containing anodes can be performed. In one embodiment, the common processing environment 301 can operate as a vacuum environment. In another embodiment, the common processing environment 301 can operate as an inert gas environment.

[0065]

[0074] The flexible substrate coating system 300 is configured as a roll-to-roll system including a feed module 302 for supplying a continuous flexible substrate, a processing module 304 for processing the continuous flexible substrate, and a take-up module 308 for collecting the continuous flexible substrate. The processing module 304 includes a chamber body 305 that defines a common processing environment 301.

[0066]

[0075] In some embodiments, the processing module 304 includes multiple processing modules or subchambers 310, 320, 330 arranged in a sequence, with each module or chamber configured to perform one processing operation on a continuous flexible substrate 110 or web of material. In one example, the subchambers 310, 320, 330 are arranged radially around the coating drum 355, as shown in FIG. 3. Additionally, arrangements other than radial are contemplated. For example, in another embodiment, the subchambers 310, 320, 330 can be positioned in a linear configuration. The subchambers 310, 320, 330 are separated by partition walls 312a-312d (collectively 312). For example, the first subchamber 310 is defined by partition walls 312a and 312b, the second subchamber 320 is defined by partition walls 312b and 312c, and the third subchamber 330 is defined by partition walls 312c and 312d. In one embodiment, the subchambers 310, 320, 330 are closed off by partition walls 312 except for a narrow arcuate gap. Although the subchambers 310, 320, 330 are illustrated as each having a single deposition source, each subchamber 310-330 can be divided into two or more compartments, each containing a separate deposition source. The compartments can be closed or isolated from adjacent compartments except for a narrow opening that allows deposition onto the coating drum 355.

[0067]

[0076] In some embodiments, the subchambers 310, 320, 330 are stand-alone modular subchambers, with each modular processing chamber being structurally isolated from the other modular subchambers. Thus, each of the stand-alone modular subchambers can be positioned, rearranged, replaced, or maintained without affecting the others. Although three subchambers 310, 320, 330 are shown, it should be understood that any number of subchambers may be included in the flexible substrate coating system 300.

[0068]

[0077] The subchambers 310, 320, 330 may include any suitable structure, configuration, arrangement, and / or components that enable the flexible substrate coating system 300 to deposit a lithium-containing anode film stack according to the embodiments described and illustrated herein. For example, but not limited to, the subchambers may include a suitable deposition system including a coating source, a power supply, individual pressure controls, a deposition control system, and a temperature control system. In some embodiments, the subchambers 310, 320, 330 are provided with individual gas supplies. As described herein, the subchambers 310, 320, 330 are generally separated from each other to provide good gas isolation. Although three subchambers 310, 320, 330 are shown, it should be understood that the processing module 304 may include any number of subchambers depending on the processing needs. For example, the flexible substrate coating system 300 may include, but is not limited to, 3, 6, or 12 subchambers.

[0069]

[0078] Each of the subchambers 310, 320, 330 may include one or more deposition sources. For example, the first subchamber 310 includes a first deposition source 313, the second subchamber 320 includes a second deposition source 315, and the third subchamber 330 includes a third deposition source 317. In general, the deposition source or sources described herein include an e-beam source and an additional source that may be selected from the group of CVD sources, PECVD sources, and various PVD sources. Exemplary PVD sources include sputtering sources, e-beam evaporation sources, and thermal evaporation sources. In one or more embodiments, the evaporation source is a lithium (Li) source. Additionally, the evaporation source may be an alloy of two or more metals. The material to be deposited (e.g., lithium) may be provided in a crucible. The lithium may be evaporated, for example, by thermal evaporation techniques or by e-beam evaporation techniques.

[0070]

[0079] In one embodiment, the first deposition source 313 is a sputtering source, the second deposition source 315 is an electron beam evaporation source, and the third deposition source 317 is a thermal evaporation source.

[0071]

[0080] In some embodiments, the subchambers 310, 320, 330 are configured to process both sides of the continuous flexible substrate 110. Although the flexible substrate coating system 300 is configured to process the continuous flexible substrate 110 oriented horizontally, the flexible substrate coating system 300 can be configured to process substrates positioned in different orientations, for example, the continuous flexible substrate 110 can be oriented vertically. In some embodiments, the continuous flexible substrate 110 is a flexible conductive substrate. In some embodiments, the continuous flexible substrate 110 includes a conductive substrate having one or more layers formed thereon. In some embodiments, the conductive substrate is a copper substrate.

[0072]

[0081] In some embodiments, the flexible substrate coating system 300 includes a substrate transport structure 352. The substrate transport structure 352 can include any transport mechanism capable of moving the continuous flexible substrate 110 through the subchambers 310, 320, 330. The substrate transport structure 352 can include a roll-to-roll system including a common take-up reel 354 positioned in the take-up module 308, a coating drum 355 positioned in the processing module 304, and a feed reel 356 positioned in the send-out module 302. The take-up reel 354, the coating drum 355, and the feed reel 356 can be heated individually. The take-up reel 354, the coating drum 355, and the feed reel 356 can be heated individually using an internal heat source positioned in each reel or an external heat source. The substrate transport structure 352 can further include one or more auxiliary transport reels 353a, 353b positioned between the take-up reel 354, the coating drum 355, and the feed reel 356. According to one embodiment, at least one of the one or more auxiliary transport reels 353a, 353b, the take-up reel 354, the coating drum 355, and the feed reel 356 can be driven and rotated by a motor.

[0073]

[0082] In some embodiments, the first metrology module 370 is positioned downstream of the plurality of subchambers 310, 320, 330 and upstream of the take-up reel 354. In some embodiments, the first metrology module 370 is positioned within the process module 304, as shown in FIG. 3. Other locations for the first metrology module 370 are also contemplated. In one example, the first metrology module 370 can be positioned within the take-up module 308. In another example, the first metrology module 370 is disposed in a separate module, which is positioned between the process module 304 and the take-up module 308.

[0074]

[0083] In some embodiments, the second metrology module 380 is positioned downstream of the plurality of subchambers 310, 320, 330 and upstream of the take-up reel 354. In some embodiments, the second metrology module 380 is positioned within the process module 304, as shown in FIG. 3. Other locations for the second metrology module 380 are also contemplated. In one example, the second metrology module 380 can be positioned within the take-up module 308. In another example, the second metrology module 380 is disposed in a separate module, which is positioned between the process module 304 and the take-up module 308.

[0075]

[0084] The flexible substrate coating system 300 includes a feed reel 356 and a take-up reel 354 for moving the continuous flexible substrate 110 through the different sub-chambers 310, 320, 330. During operation, the continuous flexible substrate 110 is unwound from the feed reel 356 as indicated by the substrate travel direction indicated by arrow 309. The continuous flexible substrate 110 may be guided via one or more auxiliary transport reels 353a, 353b. It is also possible that the continuous flexible substrate 110 is guided by one or more substrate guide control units (not shown) that control the proper running of the continuous flexible substrate 110, for example, by precise adjustment of the orientation of the continuous flexible substrate 110.

[0076]

[0085] After being unwound from the feed reel 356 and running over the auxiliary transport reel 353a, the continuous flexible substrate 110 moves through a deposition area that corresponds to the location of one or more deposition sources 313, 315, and 317 provided on the coating drum 355. After passing through the one or more deposition sources 313, 315, and 317, the processed continuous flexible substrate 110 then passes through a first metrology module 370 and a second metrology module 380 that can determine the thickness and quality of the deposited material.

[0077]

[0086] In operation, the coating drum 355 rotates about axis 351 such that the flexible substrate moves in a traveling direction represented by arrow 309 .

[0078]

[0087] The flexible substrate coating system 300 further includes a system controller 360 operable to control various aspects of the flexible substrate coating system 300. The system controller 360 facilitates control and automation of the flexible substrate coating system 300 and may include a central processing unit (CPU), memory, and supporting circuitry (or I / O). Software instructions and data for instructing the CPU may be coded and stored in the memory. The system controller 360 may communicate with one or more of the components of the flexible substrate coating system 300, for example, via a system bus. A program (or computer instructions) readable by the system controller 360 determines which tasks may be performed on the substrate. In some embodiments, the program is software readable by the system controller 360, which may include code for controlling removal and replacement of the multi-segment ring. Although the system controller 360 is illustrated as a single system controller, it is understood that multiple system controllers may be used in the embodiments described herein.

[0079]

[0088] Figure 4 is a perspective view of a portion of the flexible substrate coating system 300 of Figure 3 incorporating a second metrology module 380 according to one or more embodiments described and illustrated herein. The second metrology module 380 may be used in the flexible substrate coating system 300. The illustrated second metrology module 380 is adjacent to the coating drum 355, on which the continuous flexible substrate 110 is disposed, and the third sub-chamber 330 of the flexible substrate coating system 300. Although illustrated as part of the flexible substrate coating system 300, the second metrology module 380 may be used in other coating systems.

[0080]

[0089] In some embodiments, the third subchamber 330 is defined by a subchamber body 420 on which an edge shield 430 or mask is positioned. The third subchamber 330 includes multiple of the third deposition sources 317a-317d (collectively 317). Each of the third deposition sources 317a-317d emits a plume of evaporated material 418a-418d (collectively 418), which is attracted to the continuous flexible substrate 110 to form a patterned film of deposited material 440 on the continuous flexible substrate 110. The edge shield 430 includes one or more apertures, which define the pattern of evaporated material that is deposited on the continuous flexible substrate 110. In one example, the edge shield 430 includes two apertures 432a, 432b (collectively 432). As shown in FIG. 4, the edge shield 430 defines a patterned film of deposited material 440 on the continuous flexible substrate 110. The patterned film of deposited material 440 includes a first strip of deposited material 442a and a second strip of deposited material 442b, both of which extend in the substrate travel direction indicated by arrow 309 of the continuous flexible substrate 110. The edge shield 430 leaves an uncoated strip along a proximal end 443 of the continuous flexible substrate 110, an uncoated strip along a distal end 445 of the continuous flexible substrate 110, and an uncoated strip 447 defined between the first strip of deposited material 442a and the second strip of deposited material 442b. In one embodiment, the first aperture 432a defines the first strip of deposited material 442a and the second aperture 432b defines the second strip of deposited material 442b.

[0081]

[0090] The second metrology module 380 includes a plurality of non-contact sensors 462a-462c disposed on the first module body 460. In some embodiments, as shown in FIG. 4, the plurality of non-contact sensors 462a-462c are positioned side-by-side along a lateral direction represented by arrow 450, which is perpendicular to the direction of travel represented by arrow 309. Positioning the plurality of non-contact sensors 462a-462c along the lateral direction represented by arrow 450 allows the sensors to monitor the entire width of the continuous flexible substrate 110. The plurality of non-contact sensors 462a-462c may include any number of image sensors, eddy current sensors (ECS), and / or thickness sensors.

[0082]

[0091] 5 illustrates a spectroscopic metrology module 500 according to one or more embodiments described and illustrated herein. The spectroscopic metrology module 500 may be used in a coating system, such as the flexible substrate coating system 300 illustrated in FIGS. 3 and 4. In one example, the spectroscopic metrology module 500 may be positioned in the position occupied by the first metrology module 370. In another example, the spectroscopic metrology module 500 is positioned in the position occupied by the second metrology module 380.

[0083]

[0092] The spectroscopic measurement module 500 includes a sensor structure 505. The sensor structure 505 can be positioned within an atmospheric compartment 570 defined by a housing 572 shown in FIG. 5. The housing 572 includes at least one window 510a, 510b, and 510c (collectively 510). Although three windows 510a, 510b, 510c are shown, it should be understood that more or less than three windows 510 can be used. The number of windows 510 generally corresponds to the number of non-contact sensors within the sensor structure 505. The windows 510 can be constructed of any suitable material that can withstand the process chemistries within the coating system and allow the optical sensors to monitor the deposited material. The atmospheric compartment 570 can be sized to fit within a coating system, for example, the flexible substrate coating system 300.

[0084]

[0093] In some embodiments, the sensor structure 505 includes a strobe lamp 503 and different sets of optical systems 501a, 501b, and 501c, (collectively 501). Although three sets of optical systems 501a, 501b, and 501c are shown, it should be understood that more or less than three sets of optical systems can be used. Each set of optical systems 501 includes a lens 502, a beam splitter 504, a focusing lens 506, and a collimating lens 508. The optical systems 501a, 501b, and 501c are positioned on the successive flexible substrate 110 at different locations to capture separate two-dimensional images 522a, 522b, and 522c, respectively. The sensor structure 505 further includes a spectral grating 512 or a prism that functions as a wavelength dispersion element. The array 514 of light channeling elements 516 maps individual image elements (pixels) of the image formed by the lens 508 to respective locations along the linear slit 520 of the spectral grating 512. As described below, the array 514 of light channeling elements 516 can be implemented in a variety of ways, such as a bundle of fiber optic cables (where each light channeling element 516 is an optical fiber) or an array of microlenses (where each light channeling element 516 is a microlens). In the embodiment shown in FIG. 5, the array 514 maps a two-dimensional image 522 including an array of image elements 523a, 523b, 523c (collectively 523) from the continuous flexible substrate 110 to an ordered line of image elements along the linear slit 520. Each image element 523 is captured by a corresponding one of the light channeling elements 516.

[0085]

[0094] In some embodiments, an imager array 530, such as a charge-coupled device (CCD) array, captures the spectral image formed by the spectral grating 512. A lens assembly, represented as lens assembly 532, focuses the light from the spectral grating 512 onto the imager array 530. The image on the imager array 530 is ordered into columns 534 of pixels 536 according to a column index number "i". Each column 534 is formed from the light of a respective one of the light channeling elements 516. As shown in FIG. 5, the individual pixels 536 in each column 534 are ordered in order of decreasing wavelength, λ. Thus, each image element 523 in the captured two-dimensional image 522 is mapped to a column 534 of pixels 536 on the imager array 530, with each column 534 constituting a spectral image of one image element 523. In the embodiment of FIG. 5, there are three rows (labeled row 1, row 2, and row 3) of light channeling elements 516 in array 514 facing lens 508, and lens assembly 532 focuses the light so that the three rows are ordered from left to right across imager array 530, with each image element 523 being mapped to a wavelength dispersive column on imager array 530. Image data held in imager array 530 is provided to image processor 550, which may be part of system controller 360. Image processor 550 infers from the data which ones of light channeling elements 516 are aligned only over homogenous regions of interest of continuous flexible substrate 110, and combines their outputs to generate an enhanced spectrum. Spectral analysis processor 560, which may be part of system controller 360, analyzes the enhanced spectrum to provide a measurement of a property (e.g., film thickness) of that homogenous region of the continuous sheet of flexible material.

[0086]

[0095] As shown in Fig. 5, different rows of light channeling elements 516 (labeled row 1, row 2, and row 3) are separately coupled to different sets of optics 501a, 501b, 501c. The optics 501a, 501b, 501c are positioned on the continuous flexible substrate 110 at different locations to capture separate two-dimensional images 522a, 522b, 522c, respectively. A common strobe light 503 illuminates the optics 501a, 501b, and 501c. Using the embodiment of Fig. 5, simultaneous measurements can be made at different widely spaced zones of the continuous flexible substrate 110.

[0087]

[0096] Figure 6 is a flow diagram of a processing sequence 600 according to one or more embodiments described and illustrated herein. The processing sequence 600 can be performed using a spectroscopic metrology module, such as the spectroscopic metrology module 500 shown in Figure 5. The spectroscopic metrology module 500 can be positioned in a coating system, such as the flexible substrate coating system 300 shown in Figures 3 and 4.

[0088]

[0097] In operation 610, the strobe lamp 503 is flashed once within a defined field of view while conveying the continuous flexible substrate 110 past the sensor structure 505. In operation 620, the resulting spectral distributions at each image element within the field of view are recorded. In operation 630, each pair of distributions is compared to determine whether they are similar. The determination of similarity can be based on calculation of conventional calculations such as mean square error, sum of absolute error, or sum of variance. The processor then groups the distributions into groups of distributions that are similar to each other. The groups are then sorted by the number of distributions contained in each group. In operation 640, the n largest groups are identified, where n is the number of internal homogeneous regions of the continuous sheet of flexible material within the field of view or a smaller number. In one embodiment, the existence of similarity between any two distributions can be inferred in operation 630 whenever the sum of variances between them is less than a predefined threshold. This predetermined threshold can be varied in a trial and error procedure until the number of groups found in operation 630, n, matches the number of homogeneous regions within the field of view of the sensor. In operation 650, the processor invalidates the groups not identified in operation 630 and discards their distributions. In operation 660, for each one of the valid groups, the processor combines the distributions of that group together and outputs the combined distribution as the spectral distribution of the corresponding region of the continuous sheet of flexible material. In operation 670, the spectral analysis processor 560 processes each of the combined distributions according to conventional spectral analysis processes. The quality of the deposited film can then be reported.

[0089]

[0098] The spectroscopic metrology module 500 can be used to detect color changes in the deposited material. Such color changes are observable after metallic lithium and protective layer coatings are applied to the prelithiated anode and lithium metal anode. Thus, the color changes can be used to further facilitate precise non-contact optical-based characterization.

[0090]

[0099] 7 illustrates an eddy current sensor (ECS) module 700 according to one or more embodiments described and illustrated herein. The ECS module 700 may be used in a coating system, such as the flexible substrate coating system 300 illustrated in FIGS. 3 and 4. In one example, the ECS module 700 is positioned in the position occupied by the first metrology module 370. In another example, the ECS module 700 is positioned in the position occupied by the second metrology module 380.

[0091]

[0100] The ECS module 700 includes a sensor structure 706. The sensor structure 706 can be positioned within an atmospheric compartment 770 defined by a housing 772 shown in FIG. 7. The housing 772 includes at least one window 780a, 780b (collectively 780). Although two windows 780a, 780b are shown, it should be understood that more or less than two windows 780 can be used. The number of windows 780 generally corresponds to the number of non-contact sensors within the sensor structure 706. The window 780 can be constructed of any suitable material that can withstand the process chemistries within the coating system and allows an optical sensor to monitor the deposited material. The atmospheric compartment 770 can be sized to fit within a coating system, for example, the flexible substrate coating system 300.

[0092]

[0101] The ECS module 700 generally operates according to Faraday's law of electromagnetic induction and Lenz's law. The sensor structure 706 includes at least a pair of ECS sensors 710a, 710b (collectively 710). In some embodiments, a first ECS sensor 710a is positioned on a membrane material 702 formed on a substrate 704, and a second ECS sensor is positioned on the substrate 704. In one example, the membrane material 702 includes an anode material having a thin layer of lithium metal formed thereon. In another example, the membrane material 702 is a lithium metal anode. In one example, the substrate 704 is a continuous flexible substrate 110.

[0093]

[0102] Each ECS sensor 710a, 710b has a coil 712a, 712b (collectively 712) and a signal generator 714a, 714b (collectively 714), e.g., an alternating current (AC) signal source. Electromagnetic interaction between an AC-driven coil and a conductive object, e.g., a film material 702 or a substrate 704, through the generation of eddy currents inside the object, is generally affected by several variables. These variables include the distance from the coil to the sample, the AC frequency of the coil driver signal, the coil geometry and dimensions, the electrical conductivity of the material of the object, and, in the case of film samples, the thickness of the film, especially in cases where the thickness is less than the penetration depth of the electromagnetic field. In a typical application using film thickness measurements, the frequency, the coil geometry and dimensions, and the film conductivity are usually constants. As a result, the distance and film thickness variables are often the primary variables that affect the coil-sample interaction.

[0094]

[0103] In some embodiments, the coil 712 and the signal generator 714 are controlled by a controller, such as the system controller 360. In the embodiment shown in Figure 7, the coil 712 may be driven by the signal generator 714 at a frequency ranging from, for example, 1 kHz to 10 MHz. However, it should be understood that the particular frequency utilized will depend on the particular application, including film thickness range, material properties, lift-off distance limitations, etc.

[0095]

[0104] The coil 712, driven by a signal generator 714, generates an oscillating magnetic field that induces circulating currents within nearby conductive materials, such as the film material 702 or the substrate 704. The induced eddy currents then generate their own magnetic field that opposes the magnetic field generated by the coil 712. It should be understood that the ECS module can be used with other conductive films in addition to conductive metal films.

[0096]

[0105] The interaction between the generated and induced magnetic fields modifies the complex impedance of the coil 712. The change in complex impedance can be detected by sensing circuits 716a, 716b (collectively 716) coupled to the coil 712 and controlled by the system controller 360. In this example, the sensing circuit 716 outputs a single parameter output signal "S", e.g., resistive loss, as a function of the changed complex impedance. It should be understood that the ECS module 700 can have other types of signals and multiple parameter sensing circuits depending on the particular application. The output "S" of the sensing circuit 716 can be interpreted by a processor 740 or other computing device controlled by the system controller 360 to provide a useful measurement of the membrane material 702. The output S can be in analog or digital form. If in analog form, the processor 740 can include appropriate analog-to-digital conversion circuitry. In some embodiments, the resistive loss signal is measured in units of millivolts. It should be understood that other units of measurement can be utilized depending on the particular application. The processor 740 can be part of the system controller 360.

[0097]

[0106] The degree to which the complex impedance of the coil 712 changes is generally a function of the strength of the magnetic field induced by the eddy currents in the membrane material 702. The strength of the induced eddy currents 720 is, in turn, a function of the conductivity of the membrane material 702 and the lift-off distance "L" between the coil 712 and the material of the membrane material 702. When the film thickness T (indicated by the arrow) of the membrane material 702 is less than the penetration depth of the external magnetic field at the driving frequency of the signal oscillator 714, the induced eddy currents are also a function of the material film thickness T.

[0098]

[0107] According to one aspect of the present description, at least two unknown values, such as the lift-off distance L and the film thickness “T” of the film material 702, can be determined by comparing the output of the signal “S” of the sensing circuit 716 to previously obtained calibration data resulting from calibration of the ECS module 700.

[0099]

[0108] The ECS module 700 may further include at least one laser profilometer 790. In the embodiment of FIG. 7, the laser profilometer 790 is positioned inside the housing 772. The scanning field of the laser profilometer 790 is indicated by arrow 794. In another embodiment, the laser profilometer 790 is positioned outside the housing 772. The laser profilometer 790 may be an LVDT profilometer thickness sensor. The laser profilometer 790 may be used to measure the lift-off distance of the web. A signal 792 from the laser profilometer 790 may be transmitted to the processor 740. The lift-off distance measured by the laser profilometer 790 may be used to correct for web roughness of the continuous flexible substrate 110 movement.

[0100]

[0109] Figure 8 is a flow diagram of a processing sequence 800 according to one or more embodiments described and illustrated herein. The processing sequence 800 can be performed using a metrology module, such as the ECS module 700 shown in Figure 7. The ECS module 700 can be positioned in a coating system, such as the flexible substrate coating system 300 shown in Figures 3 and 4.

[0101]

[0110] In operation 810, non-contact electrical resistance measurements are taken from a lithium coating formed on the continuous flexible substrate 110 while conveying the continuous flexible substrate 110 past the sensor structure 706. In one embodiment, the lithium coating can be a lithium metal anode, such as the first layer 120 of the flexible layer stack 100 shown in FIG. 1. In another embodiment, the lithium coating can be a pre-lithiated layer, such as the first layer 120 of the flexible layer stack 200 shown in FIG. 2. In operation 820, a non-contact laser interferometric measurement is taken during the electrical resistance measurement. The laser interferometric measurement is used to adjust the lift-off distance of both coils to compensate for web roughness of the continuous flexible substrate 110. The laser interferometric measurement can be taken using a laser profilometer 790. In operation 830, a first lithium thickness of the coating is determined using a previously determined correlation between the electrical resistance measurement and the resistor thickness of the lithium coating, further corrected for web roughness using the laser interferometric measurement, and the electrical resistance measurement. In operation 840, the continuous flexible substrate 110 is unwound and then held for passive or active aging. In operation 850, the non-contact electrical resistance and laser interferometry measurements are repeated while winding the continuous flexible substrate 110 past the sensor to determine a second lithium thickness. The second lithium thickness may also be corrected for lift-off using the laser interferometry. In operation 860, the second lithium thickness is compared to the first lithium thickness to determine the amount of lithium intercalated into the anode.

[0102]

[0111] 9 illustrates a roughness metrology module 900 according to one or more embodiments described and illustrated herein. The roughness metrology module 900 may be used in a coating system, such as the flexible substrate coating system 300 illustrated in FIGS. 3 and 4. In one example, the roughness metrology module 900 is positioned at the location occupied by the first metrology module 370. In another example, the roughness metrology module 900 is positioned at the location occupied by the second metrology module 380.

[0103]

[0112] In some embodiments, the roughness metrology module 900 is based on a Michelson interferometer design. The roughness metrology module 900 includes a sensor structure 901. The sensor structure 901 can be positioned within an atmospheric compartment 902 defined by a housing 904 shown in FIG. 9. The housing 904 includes at least one window 906. Although one window 906 is shown, it should be understood that multiple windows 906 may be used. The number of windows 906 generally corresponds to the number of non-contact sensors within the sensor structure 901. The window 906 can be constructed of any suitable material that can withstand the process chemistries within the coating system and allows the optical sensor to monitor the deposited material. The atmospheric compartment 902 can be sized to fit within a coating system, for example, the flexible substrate coating system 300.

[0104]

[0113] In some embodiments, the roughness metrology module 900 is positioned to acquire an image of a film material 702 formed on a substrate 704. In one example, the film material 702 includes an anode material having a thin layer of lithium metal formed thereon. In another example, the film material 702 is a lithium metal anode. In one example, the substrate 704 is a continuous flexible substrate 110. The sensor structure 901 can be centered on one or more edges 705 of the film material 702. The sensor structure 901 can be positioned in the coating system behind a source of metallic lithium and a protective layer coating source.

[0105]

[0114] In some embodiments, the sensor structure 901 includes one or more polarized structured light (PSL) sources 910 that can project narrow band light onto a three-dimensional edge 705 of the film material 702, for example, a three-dimensional anode edge. The coating near the three-dimensional edge 705 typically has inherent nanoscale roughness that scatters and depolarizes the reflected polarized light. The scattering and depolarization are recorded by the image sensor 940. The contrast between the two reference waves and the emission from the film material 702 is used to calculate the roughness, which is proportional to the polarized light source. In one example, the polarized structured light source 910 is a laser source, for example, a 488 nanometer laser source.

[0106]

[0115] In some embodiments, the roughness measurement module 900 includes a polarized structure light source 910 for generating an input light beam, a beam splitter 920, and an image sensor 940. In one example, the polarized structure light source 910 is an argon laser source. Other suitable light sources can be used. In one example, the image sensor 940 is a two-dimensional (2D) detector, such as a CCD or CMOS camera. Other suitable 2D detectors can be used. In some embodiments, a polarizer 912 can be positioned at the output of the polarized structure light source 910 to provide a linearly polarized beam. The roughness measurement module 900 further includes a beam splitter 920. The input light beam from the polarized structure light source 910, after passing through the optional polarizer 912 and the beam splitter 920, impinges on a rough surface, such as the surface 703 of the film material 702. The input light beam strikes the rough surface, and the scattered light changes its polarization state due to the roughness of the rough surface. The beam splitter 920 reflects a portion of the light returning from the rough surface through a focusing lens 930 onto an image sensor 940. In one embodiment, the focusing lens 930 is an achromatic lens. In some embodiments, an adjustable aperture 950 is positioned between the focusing lens 930 and the image sensor 940. The beam splitter 920 reflects another portion of the light returning from the rough surface onto a mirror 960, e.g., a plane mirror. The mirror 960 can be tilted. In some embodiments, a quarter wave plate 970 is positioned between the mirror 960 and the beam splitter 920. By positioning the quarter wave plate 970, the electric field of the light reflected by the mirror 960 can be split into two parts providing two plane reference waves.

[0107]

[0116] The roughness measurement module 900 may further include at least one laser profilometer 990. In the embodiment of FIG. 9, the laser profilometer 990 is positioned inside the housing 904. In another embodiment, the laser profilometer 990 is positioned outside the housing 904. The laser profilometer 990 may be an LVDT profilometer thickness sensor. The scanning field of the laser profilometer 990 is indicated by an arrow 994. The laser profilometer 990 may be used to measure the lift-off distance of the web. A signal 992 from the laser profilometer 990 may be transmitted to the system controller 360. The lift-off distance measured by the laser profilometer 990 may be used to correct for web roughness of the continuous flexible substrate 110 movement.

[0108]

[0117] Figure 10 is a flow diagram of a processing sequence 1000 according to one or more embodiments described and illustrated herein. The processing sequence 1000 can be performed using a roughness metrology module, such as the roughness metrology module 900 shown in Figure 9. The roughness metrology module 900 can be positioned in a coating system, such as the flexible substrate coating system 300 shown in Figures 3 and 4.

[0109]

[0118] In operation 1010, one or more fringe patterns of polarized structured light, for example three or more fringe patterns, are projected within a defined field of view while conveying successive flexible substrates 110 through the sensor structure 901. In operation 1020, the intensity at each image element within the field of view is recorded for each fringe shift. In operation 1030, a measurement of coating roughness is determined from the distribution of image element intensities. In operation 1040, non-contact laser interferometric measurements are made inside the field of view. The non-contact laser interferometric measurements can be made during roughness measurements. The laser interferometric measurements can be used to adjust the web lift-off distance. The laser interferometric measurements can be made using the laser profilometer 990. In operation 1050, a measurement of edge coating roll-off is determined using values ​​of the distribution of image element intensities and previously determined correlations between the respective edge thickness evolutions and the image element intensities, further corrected for web lift-off using the laser profilometer measurements. In operation 1060, the PVD source and shield temperatures are adjusted to address non-conformity of the edge finish.

[0110]

[0119] All of the embodiments and 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 thereof. The embodiments described herein can be implemented as one or more non-transitory computer program products, such as one or more computer programs tangibly embodied in a machine-readable storage device, for execution by or to control the operation of a data processing apparatus, such as a programmable processor, a computer, or multiple processors or computers.

[0111]

[0120] The processes and logic flows described herein may be implemented by one or more programmable processors executing one or more computer programs that perform functions by manipulating input data and generating output. The processes and logic flows may be implemented by, and an apparatus may be implemented as, special purpose logic circuitry, such as an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0112]

[0121] The term "data processing apparatus" encompasses all apparatus, devices and machines for processing data, including, by way of example, a programmable processor, computer, or multiple processors or computers. In addition to hardware, an apparatus may include code that creates the execution environment for the computer program in question, such as code constituting a processor firmware, a protocol stack, a database management system, an operating system, or any combination or combinations of these. Processors suitable for the execution of computer programs include, by way of example, both general purpose and special purpose microprocessors, and any one or more processors of any kind of digital computer.

[0113]

[0122] Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices, including, by way of 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 may be supplemented by, or incorporated in, dedicated logic circuitry.

[0114]

[0123] The embodiments described and illustrated herein further relate to any one or more of the following Examples 1-31.

[0115]

[0124] Example 1. A flexible substrate coating system comprising a processing module including a plurality of sequentially arranged chambers, each configured to perform one or more processing operations on a continuous sheet of flexible material, and a coating drum capable of guiding the continuous sheet of flexible material through the plurality of chambers along a traveling direction, the chambers being arranged radially around the coating drum, and a metrology module including a plurality of non-contact sensors positioned side-by-side along a lateral direction perpendicular to the traveling direction.

[0116]

[0125] Example 2. A flexible substrate coating system as described in Example 1, wherein the plurality of non-contact sensors includes a spectroscopic sensor assembly operable to capture spectroscopic images of coated and uncoated portions of the continuous sheet of flexible material.

[0117]

[0126] Example 3. The flexible substrate coating system of example 1 or 2, wherein the spectroscopic sensor assembly includes a strobe light source and an imager.

[0118]

[0127] Example 4. A flexible substrate coating system according to any one of Examples 1-3, wherein the imager is a charge-coupled device (CCD) array.

[0119]

[0128] Example 5. A flexible substrate coating system as described in any one of Examples 1-4, wherein the plurality of non-contact sensors includes a first eddy current sensor operable to measure a thickness of a coated portion of the continuous sheet of flexible material, and a second eddy current sensor operable to measure a thickness of an uncoated portion of the continuous sheet of flexible material.

[0120]

[0129] Example 6. The flexible substrate coating system of any one of Examples 1-5, further comprising an optical profilometer operable to measure web roughness of the continuous sheet of flexible material.

[0121]

[0130] Example 7. A flexible substrate coating system as described in any one of Examples 1-6, wherein the plurality of non-contact sensors includes a web roughness sensor operable to measure the surface roughness of a coated portion of the continuous sheet of flexible material and an uncoated portion of the continuous sheet of flexible material.

[0122]

[0131] Example 8. A flexible substrate coating system according to any one of Examples 1-7, wherein the web roughness sensor comprises an argon laser and a CMOS camera.

[0123]

[0132] Example 9. A flexible substrate coating system as described in any one of Examples 1-8, further comprising a payout module housing a feed reel capable of providing a continuous sheet of flexible material, and a take-up module housing a return reel capable of storing the continuous sheet of flexible material.

[0124]

[0133] Example 10. The flexible substrate coating system of any one of Examples 1-9, wherein the continuous sheet of flexible material comprises a copper substrate having a lithium metal layer formed thereon.

[0125]

[0134] Example 11. The flexible substrate coating system of any one of Examples 1-10, wherein the continuous sheet of flexible material comprises a copper substrate having a lithiated anode film formed thereon.

[0126]

[0135] Example 12. The flexible substrate coating system of any one of Examples 1-11, wherein the lithiated anode film comprises a graphite anode film, a silicon-graphite anode film, or a silicon film.

[0127]

[0136] Example 13. A flexible substrate coating system according to any one of Examples 1-12, wherein the plurality of chambers comprises at least one of a sputtering source, a thermal evaporation source, and an electron beam source.

[0128]

[0137] Example 14. A method for transporting a continuous sheet of flexible material from a feed reel in a delivery chamber to a deposition module disposed downstream of the delivery chamber, the deposition module including a first coating drum capable of guiding the continuous sheet of flexible material through a plurality of deposition units, and guiding the continuous sheet of flexible material through a plurality of deposition units along a travel direction while depositing a lithium metal film on the continuous sheet of flexible material through the plurality of deposition units, the chamber including a first coating drum radially disposed around the coating drum, the chamber including a first coating drum capable of guiding the continuous sheet of flexible material through a plurality of deposition units along a travel direction, and a second coating drum positioned side by side along a lateral direction. guiding the continuous sheet of flexible material past a metrology module including a plurality of non-contact optical sensors mounted on a measuring module, the optical sensors having a field of view coincident with a path of travel of the continuous sheet of flexible material and a lateral direction perpendicular to the direction of travel; flashing a strobe lamp within the field of view while guiding the continuous sheet of flexible material past the field of view; acquiring a still image of the continuous sheet of flexible material within the field of view; channeling light reflected from each image element of the still image through a respective light channeling element to a respective position of a spectral light distributor; and recording a spectral distribution at each image element within the field of view.

[0129]

[0138] Example 15. The method of example 14, further comprising searching for distributions that are similar to each other and grouping the distributions into groups of mutually similar distributions, sorting the groups by the number of distributions contained in each group, selecting at least one of the largest groups and combining the distributions of that group together, providing the combined distribution as a spectral distribution of a region of a continuous sheet of flexible material, and processing the combined distribution according to a spectral analysis process.

[0130]

[0139] Example 16. The method of example 14 or 15, wherein the continuous sheet of flexible material comprises a copper substrate, and the lithium metal film is formed on the copper substrate.

[0131]

[0140] Example 17. The method of any one of Examples 14-16, wherein the continuous sheet of flexible material comprises a copper substrate having an anode film formed thereon, and a lithium metal film is formed on the anode film.

[0132]

[0141] Example 18. The method of any one of Examples 14-17, wherein the anode film is selected from a graphite anode film, a silicon-graphite anode film, or a silicon film.

[0133]

[0142] Example 19. A method comprising: transporting a continuous sheet of flexible material from a feed reel in a delivery chamber to a deposition module disposed downstream of the delivery chamber, the deposition module including a first coating drum capable of guiding the continuous sheet of flexible material through a plurality of deposition units; guiding the continuous sheet of flexible material through a plurality of deposition units along a traveling direction while depositing a lithium metal film on the continuous sheet of flexible material through the plurality of deposition units, the chamber being radially disposed around the coating drum; guiding the continuous sheet of flexible material through a measurement module including a plurality of non-contact optical sensors positioned side by side along a lateral direction, the optical sensors having a field of view that coincides with a path of travel along which the continuous sheet of flexible material travels, the lateral direction being perpendicular to the direction of travel; and obtaining a first non-contact electrical resistance measurement of the lithium metal film on the continuous sheet of flexible material within the field of view.

[0134]

[0143] Example 20. The method of example 19, further comprising determining a first thickness of the lithium metal film using the first non-contact electrical resistance measurement.

[0135]

[0144] Example 21. The method of example 19 or 20, wherein determining the first thickness of the lithium metal film includes comparing the first non-contact electrical resistance measurement to a previously determined correlation between the electrical resistance measurements and respective thicknesses of the lithium metal film.

[0136]

[0145] Example 22. The method of any one of Examples 19-21, further comprising obtaining non-contact laser interferometric measurements of the continuous sheet of flexible material within the field of view.

[0137]

[0146] Example 23. The method of any one of Examples 19-22, further comprising determining web roughness of the continuous sheet of flexible material based on non-contact laser interferometry measurements of the continuous sheet of flexible material.

[0138]

[0147] Example 24. The method of any one of Examples 19-23, further comprising adjusting the lithium metal film first thickness measurement based on the web roughness to determine a corrected lithium metal film first thickness.

[0139]

[0148] Example 25. The method of any one of Examples 19-24, further comprising aging the lithium metal film for a period of time.

[0140]

[0149] Example 26. The method of any one of Examples 19-25, comprising obtaining a second non-contact electrical resistance measurement of the lithium metal film on the continuous sheet of flexible material within the field of view after aging the lithium metal film for a period of time, and determining a second thickness of the lithium metal film using the second non-contact electrical resistance measurement.

[0141]

[0150] Example 27. The method of any one of Examples 19-26, wherein determining the second thickness of the lithium metal film includes comparing the second non-contact electrical resistance measurement to a previously determined correlation between the electrical resistance measurements of the lithium metal film and their respective thicknesses.

[0142]

[0151] Example 28. The method of any one of Examples 19-27, further comprising determining an amount of prelithiation of the anode film deposited on the continuous sheet of flexible material by comparing the first thickness of the lithium metal film to the second thickness of the lithium metal film.

[0143]

[0152] Example 29. The method of any one of Examples 19-28, wherein the continuous sheet of flexible material comprises a copper substrate, and the lithium metal film is formed on the copper substrate.

[0144]

[0153] Example 30. The method of any one of Examples 19-29, wherein the continuous sheet of flexible material comprises a copper substrate having an anode film formed thereon, and a lithium metal film is formed on the anode film.

[0145]

[0154] Example 31. The method of any one of Examples 19-30, wherein the anode film is selected from a graphite anode film, a silicon-graphite anode film, or a silicon film.

[0146]

[0155] While the above description is directed to embodiments of the present disclosure, other and further embodiments may be devised without departing from the basic scope of the present disclosure, the scope of the present disclosure being determined by the claims. All documents described herein, including any priority documents and / or test procedures, are incorporated herein by reference to the extent that they do not contradict the contents of the present disclosure. As is apparent from the summary and specific embodiments above, forms of the present disclosure have been shown and described, but various modifications can be made without departing from the spirit and scope of the present disclosure. Thus, it is not intended that the present disclosure be limited by the forms of the present disclosure. Similarly, the word "comprising" is considered synonymous with the words "including" or "having" as interpreted under US law. Similarly, whenever a composition, element, or group of elements precedes the transitional phrase "comprising," it is assumed that the same composition or group of elements has the transitional phrase "consisting essentially of," "consisting of," "selected from the group consisting of," or "is," following the recitation of the composition, element, or group, and vice versa. When introducing elements of the disclosure or exemplary aspects or one or more embodiments thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements.

[0147]

[0156] Some embodiments and features have been described using a set of upper numerical limits and a set of lower numerical limits. It is to be understood that ranges including any combination of two values ​​are envisioned, for example, any lower value with any upper value, any two lower values, and / or any two upper values, unless otherwise indicated. One or more claims are set forth with specific lower limits, upper limits, and ranges.

Claims

1. a plurality of sequentially arranged chambers, each configured to perform one or more processing operations on a continuous sheet of flexible material; and A coating drum capable of guiding the continuous sheet of flexible material along a direction of travel through a plurality of chambers, the chambers being radially arranged around the coating drum. a processing module including: a measurement module including a plurality of non-contact sensors positioned side by side along a lateral direction perpendicular to the direction of travel; 1. A flexible substrate coating system comprising:

2. The coating system of claim 1 , wherein the plurality of non-contact sensors comprises a spectroscopic sensor assembly operable to capture spectroscopic images of coated and uncoated portions of the continuous sheet of flexible material.

3. The coating system of claim 2 , wherein the spectroscopic sensor assembly includes a strobe light source and an imager.

4. The coating system of claim 3 , wherein the imager is a charge-coupled device (CCD) array.

5. 2. The coating system of claim 1, wherein the plurality of non-contact sensors includes a first eddy current sensor operable to measure a thickness of a coated portion of the continuous sheet of flexible material and a second eddy current sensor operable to measure a thickness of an uncoated portion of the continuous sheet of flexible material.

6. The coating system of claim 1 , further comprising an optical profilometer operable to measure web roughness of the continuous sheet of flexible material.

7. 2. The coating system of claim 1 , wherein the plurality of non-contact sensors comprises a web roughness sensor operable to measure a surface roughness of a coated portion of the continuous sheet of flexible material and an uncoated portion of the continuous sheet of flexible material.

8. The coating system of claim 7 , wherein the web roughness sensor comprises an argon laser and a CMOS camera.

9. a delivery module housing a feed reel capable of providing a continuous sheet of said flexible material; a take-up module housing a take-up reel capable of storing the continuous sheet of flexible material; 10. The coating system of claim 1 further comprising:

10. 10. The coating system of claim 9, wherein the continuous sheet of flexible material comprises a copper substrate having a lithium metal layer formed thereon.

11. 10. The coating system of claim 9, wherein the continuous sheet of flexible material comprises a copper substrate having a lithiated anode film formed thereon.

12. The coating system of claim 11 , wherein the lithiated anode film comprises a graphite anode film, a silicon-graphite anode film, or a silicon film.

13. The coating system of claim 12 , wherein the multiple chambers include at least one of a sputtering source, a thermal evaporation source, and an electron beam source.

14. A method for processing a flexible substrate, comprising: conveying a continuous sheet of flexible material from a feed reel in a delivery chamber to a deposition module disposed downstream of said delivery chamber, said deposition module including a first coating drum capable of guiding said continuous sheet of flexible material through a plurality of deposition units; guiding the continuous sheet of flexible material along a traveling direction past a plurality of deposition units while depositing a lithium metal film on the continuous sheet of flexible material through the plurality of deposition units, wherein the plurality of deposition units are radially disposed around the coating drum; guiding the continuous sheet of flexible material past a metrology module including a plurality of non-contact optical sensors positioned side-by-side along a lateral direction, wherein the optical sensors have a field of view coincident with a path of travel of the continuous sheet of flexible material, the lateral direction being perpendicular to the direction of travel; flashing a strobe lamp within the field of view while guiding the continuous sheet of flexible material through the field of view; capturing a still image of the continuous sheet of flexible material within the field of view; channeling light reflected from each image element of the still image through a respective light channeling element to a respective position of a spectral light distributor; and recording the spectral distribution for each image element within said field of view; The method includes:

15. searching for distributions that are similar to each other and grouping said distributions into groups of distributions that are similar to each other; classifying the groups according to the number of distributions contained in each group; selecting at least one of the largest groups and combining the distributions of that group together to provide the combined distribution as the spectral distribution of a region of the continuous sheet of flexible material; and processing said combined distribution according to a spectral analysis process; The method of claim 14 further comprising:

16. 16. The method of claim 15, wherein the continuous sheet of flexible material comprises a copper substrate, and the lithium metal film is formed on the copper substrate.

17. 16. The method of claim 15, wherein the continuous sheet of flexible material comprises a copper substrate having an anode film formed thereon, the lithium metal film being formed on the anode film, the anode film being selected from a graphite anode film, a silicon-graphite anode film, or a silicon film.

18. A method for processing a flexible substrate, comprising: conveying a continuous sheet of flexible material from a feed reel in a delivery chamber to a deposition module disposed downstream of said delivery chamber, said deposition module including a first coating drum capable of guiding said continuous sheet of flexible material through a plurality of deposition units; guiding the continuous sheet of flexible material along a traveling direction past a plurality of deposition units while depositing a lithium metal film on the continuous sheet of flexible material through the plurality of deposition units, wherein the plurality of deposition units are radially disposed around the coating drum; guiding the continuous sheet of flexible material past a metrology module including a plurality of non-contact optical sensors positioned side-by-side along a lateral direction, where the optical sensors have a field of view coincident with a path of travel along which the continuous sheet of flexible material travels, the lateral direction being perpendicular to the direction of travel; and obtaining a first non-contact electrical resistance measurement of the lithium metal film on the continuous sheet of flexible material within the field of view; The method includes:

19. determining a first thickness of the lithium metal film using the first non-contact electrical resistance measurement, where determining the first thickness of the lithium metal film includes comparing the first non-contact electrical resistance measurement to previously determined correlations between electrical resistance measurements and respective thicknesses of lithium metal films; obtaining non-contact laser interferometric measurements of the continuous sheet of flexible material within the field of view; determining web roughness of the continuous sheet of flexible material based on the non-contact laser interferometry measurements of the continuous sheet of flexible material; adjusting the first thickness measurement of the lithium metal film based on the web roughness to determine a revised first thickness of the lithium metal film; and Aging the lithium metal film for a certain period of time.

20. The method of claim 18, further comprising:

20. obtaining a second non-contact electrical resistance measurement of the lithium metal film on the continuous sheet of flexible material within the field of view after aging the lithium metal film for a period of time; determining a second thickness of the lithium metal film using the second non-contact electrical resistance measurement, where determining the second thickness of the lithium metal film includes comparing the second non-contact electrical resistance measurement to previously determined correlations between electrical resistance measurements and respective thicknesses of lithium metal films; and determining an amount of prelithiation of an anode film deposited on the continuous sheet of flexible material by comparing the first thickness of the lithium metal film to the second thickness of the lithium metal film.

20. The method of claim 19, further comprising:

Images