Lithium metal anode mass production

Abstract

Electrode device stacks including patterned alkali metal containing electrodes and methods and systems for manufacturing the same are provided. Alkali metal anodes can be produced by transferring patterned lithium from a carrier substrate, for example, a plastic substrate, onto a current collector or anode material. Prior to transferring the patterned alkali metal, the laser lift-off (LLO) patterning process removes unwanted alkali metal from the carrier substrate to form the patterned alkali metal on the carrier substrate. Calendering followed by peel-off of the carrier substrate transfers the patterned alkali metal from the carrier substrate to the current collector or anode material. Finally, multiple alkali metal anode rolls are produced by slitting the current collector having the patterned alkali metal formed thereon.

Description

LITHIUM METAL ANODE MASS PRODUCTIONTECHNICAL FIELD

[0001] The disclosure generally relates to alkali metal containing energy storage devices and methods for manufacturing alkali metal containing energy storage devices. More particularly, the disclosure relates to device stacks including patterned alkali metal containing electrodes and methods for manufacturing the same.BACKGROUND

[0002] Rechargeable electrochemical storage systems are currently becoming increasingly essential for many fields of everyday life. High-capacity electrochemical energy storage devices, such as lithium-ion (Li-ion) batteries, are used in a growing number of applications, including portable electronics, medical, transportation, grid- connected large energy storage, renewable energy storage, and uninterruptible power supply (UPS). Traditional lead / sulfuric acid batteries often lack the capacitance and are often inadequately cyclable for these growing applications. Lithium-ion batteries, however, are thought to provide the best solution.

[0003] Therefore, there is a need for methods and systems for the deposition and processing of alkali metals used in energy storage devices.SUMMARY

[0004] In one aspect, a flexible substrate processing system is provided. The system includes a first supply hub for supplying a flexible carrier film having an alkali metal film formed thereover and a second supply hub for supplying a sacrificial film. The system further includes a first pickup hub for collecting the flexible carrier film having a patterned alkali metal film formed thereover, the patterned alkali metal film formed by exposing portions of the alkali metal film to laser energy, the patterned alkali metal film including unexposed portions of the alkali metal film. The system further includes a second pickup hub for collecting the sacrificial film, the sacrificial film having the exposed portions of the alkali metal film formed thereover. The system further includes a laser lift-off unit positioned downstream from the first supply hub and the second supply hub and upstream from the first pickup hub and the second pickup hub. The laser lift-off unit includes a laser source configured to generate laserenergy, the laser energy directed toward the alkali metal film and an optical scanner configured to direct the laser energy toward the alkali metal film.

[0005] Implementations may include one or more of the following. The flexible substrate processing system further includes a pair of rollers positioned downstream of the first supply hub and the second supply hub and upstream of the laser source, the pair of rollers positioned to contact the alkali metal film to the sacrificial film. The pair of rollers include at least one nip roller. The pair of rollers include at least one calender roller. The laser source is selected from an infrared (IR) fiber laser, an ultraviolet (UV) laser, or a Green Laser. The optical scanner is a single- or multi-axis large angle galvanometer optical scanner. The optical scanner is a polygon scanner, an electro-optic scanner, an acousto-optic, or a combination thereof. The flexible substrate processing system further includes a passivation unit positioned downstream from the laser lift-off unit and upstream from the second pickup hub, the passivation unit positioned to passivate the alkali metal film formed on the flexible carrier film. The flexible substrate processing system further includes an inline slitting assembly including a blade for cutting the flexible carrier film, the inline slitting assembly positioned downstream from the laser lift-off unit and upstream from the first pickup hub. The flexible substrate processing system further includes a third supply hub for supplying a flexible substrate film stack and a third pickup hub for collecting the flexible substrate film stack having the patterned alkali metal film formed thereon.

[0006] In another aspect, a flexible substrate processing system for forming an energy storage device is provided. The flexible substrate processing system includes a laser lift-off unit. The laser lift-off unit includes a laser source configured to generate laser energy, the laser energy directed toward a first surface of a flexible carrier film having an alkali metal film formed thereover. The laser lift-off unit further includes an optical scanner configured to direct the laser energy toward the first surface of the flexible carrier film. The flexible substrate processing system further includes a system controller configured to cause the laser lift-off unit to perform a process. The process includes conveying a flexible carrier film stack including the flexible carrier film having the alkali metal film formed thereover from a supply hub toward a pickup hub; contacting the flexible carrier film stack with a sacrificial film, wherein the alkali metal film contacts the sacrificial film; exposing portions of the alkali metal film to the laser energy to pattern the alkali metal film; and removing the sacrificial film from theflexible carrier film stack to form the patterned alkali metal film on the flexible carrier film stack, the patterned alkali metal film including unexposed portions of the alkali metal film and the sacrificial film having the exposed portions of the alkali metal film formed thereon.

[0007] Implementations may include one or more of the following. The laser source is selected from an infrared (IR) fiber laser, an ultraviolet (UV) laser, or a Green Laser. The optical scanner is a single- or multi-axis large angle galvanometer optical scanner. The flexible substrate processing system further includes a pair of rollers positioned upstream of the laser source, the pair of rollers contacting the flexible carrier film stack with the sacrificial film. The pair of rollers include at least one nip roller. The pair of rollers include at least one calender roller.

[0008] In yet another aspect, a method of forming a film stack for an energy storage device is provided. The method includes conveying a flexible carrier film stack including a flexible carrier film having an alkali metal film formed thereover from a supply hub toward a pickup hub. The method further includes contacting the flexible carrier film stack with a sacrificial film, wherein the alkali metal film contacts the sacrificial film. The method further includes exposing portions of the alkali metal film to the laser energy to separate the exposed portions of the alkali metal film from the flexible carrier film. The method further includes removing the sacrificial film and the exposed portions of the alkali metal film from the flexible carrier film stack to form a patterned alkali metal film on the flexible carrier film, the sacrificial film having the exposed portions of the alkali metal film formed thereon.

[0009] Implementations may include one or more of the following. The laser energy is directed through a backside of the flexible carrier film. Exposing the flexible carrier film stack to laser energy creates a void volume between the alkali metal film and the flexible carrier film stack. The flexible carrier film stack further includes a release layer disposed between the flexible carrier film and the alkali metal film, the release layer is capable of photoinduced depolymerization.

[0010] In another aspect, a non-transitory computer readable medium has stored thereon instructions, which, when executed by a processor, causes the process to perform operations of the above apparatus and / or method.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, and may admit to other equally effective embodiments.

[0012] FIG. 1 illustrates a side cross-sectional view of a transfer system incorporating one or more laser lift-off units in accordance with one or more implementations of the present disclosure.

[0013] FIG. 2 illustrates a side cross-sectional view of one example of a laser liftoff unit in accordance with one or more implementations of the present disclosure.

[0014] FIG. 3 illustrates a side cross-sectional view of another example of a laser lift-off unit in accordance with one or more implementations of the present disclosure.

[0015] FIG. 4 illustrates a side cross-sectional view of one example of a laser liftoff system in accordance with one or more implementations of the present disclosure.

[0016] FIG. 5 illustrates a side cross-sectional view of another example of a transfer system in accordance with one or more implementations of the present disclosure.

[0017] FIG. 6 illustrates an exemplary flow chart of a method in accordance with one or more implementations of the present disclosure.

[0018] FIGS. 7A-7F illustrate side views of various stages of manufacturing an anode structure according to the method of FIG. 6 in accordance with one or more implementations of the present disclosure.

[0019] FIGS. 8A-8E illustrate top views of various stages of manufacturing an anode structure according to the method of FIG. 6 in accordance with one or more implementations of the present disclosure.

[0020] FIGS. 9A-9C illustrate top views of flexible carrier stacks formed in accordance with one or more implementations of the present disclosure.

[0021] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.DETAILED DESCRIPTION

[0022] The disclosure generally relates to alkali metal containing energy storage devices and methods for manufacturing alkali metal containing energy storage devices. More particularly, the disclosure relates to device stacks including patterned alkali metal containing electrodes and methods for manufacturing the same.

[0023] Substrate independent direct transfer (SIDT) is a method for forming electrode device stacks by transferring one or more layers including an alkali metal layer, for example, a lithium metal layer, to a substrate stack, for example, a current collector in implementations where lithium metal functions as an anode or for pre- lithiating an anode material which is already formed on the current collector. The alkali metal or alloy includes an alkali metal, for example, lithium metal, sodium, potassium, rubidium, cesium, francium, an alloy including the alkali metal, or a combination thereof. The already formed anode material can include or be, but is not limited to, graphite, silicon, silicon graphite, silicon oxide graphite, silicon, tin, hard carbon, metal oxide, or combinations thereof. The alloy including the alkali metal can include an alloy of the alkali metal and the anode material. The current collector can include or be metalized plastic, copper, or combinations thereof. In SIDT processes, alkali metal is formed over a flexible carrier substrate composed of one or more materials such as a plastic substrate, for example, polyethylene terephthalate (PET), paper, or combinations thereof. The materials formed on the flexible support layer stack are directly transferred to a substrate stack. The substrate stack can include or be a current collector, a current collector having anode material formed thereover, a metallized plastic substrate, a separator, or a metallized plastic substrate having alkali metal formed thereover. A release layer, if present, is formed between the alkali metal layer and the flexible carrier substrate. The release layer enables transferring alkali metal and other materials off of the flexible carrier substrate and onto the currentcollector or anode material if already present. The release layer can be selected from one or more of fluorocarbons, silicone, latex, AIOx, LiF, AIOOH, Ag, AgF, Bi, Zn, Mg, Sn, or metal halides.

[0024] The conventional process of SIDT after slitting only generates a single lane anode roll. Thus, production of narrow width rolls using conventional SIDT processes involves a large number of SIDT tools. In one or more implementations of the present disclosure, alkali metal anodes can be produced by transferring patterned lithium from a carrier substrate, for example, a plastic substrate, onto a current collector or anode material. Prior to transferring the patterned alkali metal, the laser lift-off (LLO) patterning process removes unwanted alkali metal from the carrier substrate to form the patterned alkali metal on the carrier substrate. Calendering followed by peel-off of the carrier substrate transfers the patterned alkali metal from the carrier substrate to the current collector or anode material. Finally, multiple alkali metal anode rolls are produced by slitting the current collector having the patterned alkali metal formed thereon. Thus minimizing equipment investment costs and factory space occupancy by maximizing the efficiency of wider-width lithium production.

[0025] In one or more implementations, which can be combined with other implementations, the laser lift-off process provides a pre-patterned alkali metal layer on a plastic film roll.

[0026] In one or more implementations, which can be combined with other implementations, an IR nanosecond fiber laser is used to remove unwanted alkali metal area coated on a plastic film roll, for example, a carrier substrate. Portions of the alkali metal that are exposed to the laser energy are removed from the plastic film roll while unexposed portions of the alkali metal remain on the carrier substrate defining the patterned alkali metal layer. The patterned alkali metal layer is transferred from the plastic roll to a current collector or anode material by calendering and peel- off of the plastic film. In the area where unwanted lithium was removed by exposure to laser energy during the laser lift-off (LLO) patterning process, the current collector is exposed and becomes a space for a tab or slitting. Blade or laser can cut the exposed current collector resulting in multiple alkali metal anode rolls. To do this process, the LLO lane cleaning and slitting tools and SIDT tools may be used. The tools can be configured as a roll-to-roll system to produce anodes in roll format.

[0027] In one or more implementations, which can be combined with other implementations, systems and methods for patterned alkali metal transfer onto a substrate stack utilizing a laser-lift off process are provided. The substrate stack can be or include a current collector substrate, for example, a copper substrate or a metalized plastic substrate and optionally an anode material, for example, one of more of silicon graphite, SiOx-Gr, or graphite. The LLO process is performed using an energy source generally adapted to deliver electromagnetic energy to a targeted region of a carrier substrate stack. The energy source for delivering electromagnetic energy can include and optical radiation source, for example, a laser source or a flash lamp. Suitable laser sources include but are not limited to an IR fiber laser, a UV laser, or a Green Laser. Suitable flash lamp sources include, for example, xenon or krypton flash lamps, which may be used in place of or in conjunction with the laser sources. Not to be bound by theory but it is believed that the energy source activates selected portions of the alkali metal at the interface of the alkali metal film and the carrier substrate, for example, the PET-Li interface, from the carrier substrate side and the exposed portions of the alkali metal are either removed by either transferring the exposed portions to either a sacrificial film or removing the exposed portions with a suction device. The unexposed portions of the alkali metal form the patterned alkali metal film. The patterned alkali metal film may then be transferred from the carrier substrate onto the substrate stack. The patterned alkali metal at the activated carrier substrate-alkali metal interface may be subsequently released from the carrier substrate during removal of the carrier substrate.

[0028] In one or more implementations, which can be combined with other implementations, the laser-lift off patterning process described can be incorporated into a roll-to-roll tool and used in a roll-to-roll process or performed in a dedicated laser lift-off tool. The laser-lift off patterning process patterns an alkali metal film formed over a plastic carrier substrate by exposing portions of the alkali metal film to electromagnetic energy. The exposed portions of the alkali metal film are subsequently removed from the plastic carrier substrate using either a sacrificial film, a suction device, or a combination thereof. The unexposed portions of the alkali metal film remain on the plastic carrier substrate and form the patterned alkali metal film. The patterned alkali metal film may be transferred from the plastic carrier substrate onto a substrate stack. The substrate stack can be or include a current collectorsubstrate, for example, a copper substrate or a metalized plastic substrate and optionally an anode material, for example, one of more of silicon graphite, SiOx-Gr, or graphite. Transfer from the plastic carrier substrate onto the substrate stack may be performed via a lamination process, for example, a calendering process or a LLO transfer process. During the LLO transfer process, the patterned alkali metal is transferred from the plastic carrier substrate onto the substrate stack by exposing an interface between the alkali metal film and the plastic carrier substrate, for example, the Li-PET interface, to laser energy which induces alkali metal transfer at the interface. The interface between the alkali metal layer and the flexible carrier film may also include a release layer as described.

[0029] In one or more implementations, which can be combined with other implementations, the laser lift-off process enables the patterning of alkali metal. The alkali metal film can be patterned to match the pattern of an already deposited material, for example, an anode material, in a lane coating process or a skip coating process. In some implementations, the patterned alkali metal can be transferred directly onto a current collector substrate. Any suitable pattern may be achieved using the laser lift-off patterning process, for example, a square, a triangle, or a circle.

[0030] In one or more implementations, which can be combined with other implementations, the laser lift-off patterning process uses a laser source to create an interface reaction with either a release layer, an interface layer, or both the release layer and the interface layer between the alkali metal layer and the flexible carrier film, for example, a PET film, to enable subsequent removal of exposed portions of the alkali metal film the flexible carrier film at the activated interface.

[0031] In one or more implementations, which can be combined with other implementations, a flexible carrier film stack is provided. The flexible carrier film stack can include a plastic containing substrate, for example, a polyethylene terephthalate (PET) substrate. The flexible carrier film stack can further include a release layer, for example, silicone or other deposited release layers, formed on the flexible carrier film stack. An alkali metal layer, for example, a lithium metal layer is formed over the flexible carrier film stack. In some implementations where the release layer is not present, the alkali metal layer can be formed directly on the plastic containing substrate. In implementations where the release layer is present, the alkali metal layercan be formed directly on the release layer. The flexible carrier film stack having the alkali metal layer formed thereon is exposed to a laser lift-off patterning process. In one or more implementations, during the laser lift-off patterning process, a laser is directed through the flexible carrier film stack to activate the interface of the alkali metal layer and the flexible carrier film stack, for example, the Li-PET interface. The laser can be directed through the backside of the flexible carrier film stack, for example, from the plastic containing substrate or PET side. Exposure to the laser can induce an alkali metal transfer process creating a void volume between the alkali metal layer and the flexible carrier film stack. The void volume can make separation of the exposed portions of the alkali metal layer from the flexible carrier film stack easier during removal of the exposed portions of the alkali metal film from the flexible carrier film stack leaving unexposed portions of the alkali metal film on the flexible carrier film to form the patterned alkali metal film on the flexible carrier film stack. In addition, precise laser beam position control enables the selective removal of portions of the alkali metal from the flexible carrier film to form targeted shapes on the flexible carrier film stack. The targeted shapes can be subsequently transferred to the substrate stack to form electrode device stacks with various shapes. A cathode structure and / or separator can be integrated with the formed electrode device stack to form the energy storage device.

[0032] In one or more implementations, which can be combined with other implementations, an IR fiber laser is used for the laser-lift of patterning process. The laser-lift of patterning process can include laser activation and lift-off from a PET substrate with an alkali metal layer, for example, a 20 urn lithium layer, and a silicone release layer. In one example, the IR fiber laser is a 1060-nm laser with a pulse width of 5 to 500 nanoseconds, for example, a 30 nanosecond pulse width, a Gaussian profile, ~150 urn spot size, 2 m / sec raster speed, and a line distance of 70 urn.

[0033] Laser parameters selection, such as pulse width, can be fundamental to developing a successful laser lift-off patterning process that minimizes damage to the underlying substrate during the laser lift-off patterning process while achieving a clean pattern. A high frequency nanosecond-pulsed IR laser or picosecond-pulsed IR laser can be used based on laser-material interaction specific to lithium material stacks. Lithium is unique in that its melting temperature is only 453.65 K (180.50 °C) while the boiling temperature is 1603 K (1330 °C), which is still very high. In comparison, PEThas a melting temperature of 523 K (250 °C), and a boiling temperature 623 K (350 °C). For a conductive substrate such as copper, it has a much lower absorption to IR laser than to green (~520 — 540 ns) or UV laser (< 360 nanometer). For example, at ambient temperature, a 1064-nanometer laser has less than 5% optical absorption in copper, while a 532-nanometer Green laser has about 40% optical absorption in copper. The 1064-nanometer laser in a melted copper liquid still has about 5% optical absorption. From the aspect of avoiding copper damage, the 1 -pm IR laser wavelength is more advantageous than a Green or UV laser wavelength. In addition, at the same average power level and with the same type of laser, an IR laser is more reliable and cost-effective.

[0034] An IR nanosecond laser with a pulse duration of less than 30 nanoseconds and a near-infrared wavelength of 1064-nanometer is suitable for the LLO patterning process. However, ultrashort pulsed lasers may be used for some purposes like quality improvement. The laser with a longer pulse duration generates a higher density plasma resulting in a greater gas pressure to release the interface between the PET carrier film and the lithium film. However, pulse duration longer than 50 nanoseconds involves much higher pulse energy (or laser power) due to a low peak power. On the contrary, a shorter pulse duration can process precisely to achieve a cleaner lithium edge.

[0035] Laser parameters can be selected with benefits and advantages such as providing sufficiently high laser intensity to achieve patterning of lithium and to minimize damage to the underlying substrate. Also, parameters can be selected to provide meaningful process throughput for industrial applications with precisely controlled ablation width, for example, kerf width, and depth. As described, an ultrashort pulse (USP) laser, for example, a laser with a pulse duration of, at most, in a femtosecond range, such as a femtosecond or picosecond pulse laser is suitable for providing such advantages. Such pulse width ranges for UPS may be 5 femtosecond to 999 femtoseconds, preferably 10 femtoseconds to 999 femtoseconds for a femtosecond pulse laser and 1 picosecond to 10 picoseconds for a picosecond pulse laser. Regarding USPs, a shorter pulse width results in higher peak power and fewer thermal effects, which increases control over the removal rate. For example, a 10 femtosecond pulse has 1000 times higher peak power than a 10 picosecond pulse of the same pulse energy. Therefore, the wavelength range is of less importance aspatterning may be ceased at a precise depth without thermally damaging the underlying substrate.

[0036] However, nanosecond-pulse laser lift-off is also suitable, as pulses longer than a few tens of picoseconds will start having more pronounced thermal effects. Nanosecond pulse lasers are also more cost-effective, although certain wavelengths may provide better performance than others. For a PET substrate, a wavelength range of about 450 nm to about 1600 nm, or from about 450 nm to about 1550 nm, will facilitate laser lift-off of lithium with nanosecond pulses such that the PET film is highly transparent to light. A wavelength of less than 450 nm, or less than 355 nm, may result in scribing or cutting of the PET substrate. For a polyimide (PI) substrate, a wavelength in a range from about 700 nm to about 1700 nm, or in a range from about 750 nm to about 1600 nm, will provide laser lift-off of lithium using nanosecond pulses. Similarly, a wavelength of less than 450 nm may scribe or cut the PI substrate.

[0037] The nanosecond pulses may range in a range from about 1 nanosecond to about 200 nanoseconds, or in a range from about 1 nanosecond to about 50 nanoseconds, or in a range from about 1 nanosecond to about 10 nanoseconds. For example, in one implementation, a nanosecond-pulse laser process having a wavelength closer to or in the IR range provides a cleaner patterning process than a nanosecond-pulse laser process having a wavelength closer to or in the UV range. In one or more implementations, a femtosecond-pulse laser process suitable for laser lift-off patterning processes is based on a laser having a wavelength of approximately greater than or equal to one micrometer. In a particular implementation, pulses of approximately less than or equal to 15 nanoseconds of the laser having the wavelength of approximately greater than or equal to one micrometer are used. However, in an alternative implementation, dual laser wavelengths, for example, a combination of an IR laser and a UV laser, can be used.

[0038] It is noted that while the particular substrate on which some implementations described herein can be practiced is not limited, it is particularly beneficial to practice the implementations on flexible substrates, including for example, web-based substrates, panels and discrete sheets. The flexible substrate can also be in the form of a foil, a polymer film, or a thin plate.

[0039] It is also noted here that a flexible substrate, film, or web as used within the implementations described herein can typically be characterized in that it is bendable. The term “web” can be synonymously used to the term “strip,” the term “flexible film,” the term “flexible substrate,” or the term “flexible conductive substrate.” For example, the web as described in implementations herein can be a polymer material.

[0040] It is further noted that the methods and systems described may be used in forming single-sided electrode structures and double-sided electrode structures.

[0041] FIG. 1 illustrates a side cross-sectional view of a transfer system 100 incorporating one or more laser lift-off (LLO) units in accordance with one or more implementations of the present disclosure. The transfer system 100 includes equipment for transferring alkali metal films on a first flexible carrier 110 and a second flexible carrier 120 to each side of a flexible substrate stack 130, so that the flexible substrate stack 130 with the alkali metal films can be used as an electrode (e.g., anode) in a lithium-ion battery. The transfer system 100 includes a calendering unit 140 to transfer the lithium films on the flexible carriers 110, 120 to the flexible substrate stack 130. The transfer system 100 further includes one or more laser lift-off units 200, 300 for patterning an alkali metal formed on the flexible carriers 110, 120. Additional details on the laser lift-off unit 200 is described in reference to FIG. 2 below. Additional details on the laser lift-off unit 300 is described in reference to FIG. 3 below.

[0042] The transfer system 100 includes a first flexible carrier supply hub 115. A supply roll 111 of the first flexible carrier 110 is positioned on the first flexible carrier supply hub 115. The first flexible carrier 110 includes an upper surface 110U and a lower surface 110L. In some implementations, the first flexible carrier 110 can be formed of a polymer material, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), or combinations thereof. An alkali metal film (not shown in FIG. 1 ) is positioned on the lower surface 110L of the first flexible carrier 110, so that the alkali metal film faces an upper surface 130U of the flexible substrate stack 130 as the first flexible carrier 110 and the flexible substrate stack 130 are conveyed through the calendering unit 140. The alkali metal film is shown as the alkali metal film 241 in FIG. 2. The upper surface 130U of the flexible substrate stack 130 is on an opposite side relative to a lower surface 130L of the flexible substrate stack 130. The upper surface 130U is also referred to as the first surface or the first side ofthe flexible substrate stack 130 while the lower surface is also referred to as the second surface or the second side of the flexible substrate stack 130.

[0043] The transfer system 100 includes a second flexible carrier supply hub 125. A supply roll 121 of the second flexible carrier 120 is positioned on the second flexible carrier supply hub 125. The second flexible carrier 120 includes an upper surface 120U and a lower surface 120L. In some implementations, the second flexible carrier 120 can be formed of a same material (e.g., PET) as the first flexible carrier 110. An alkali metal film (not shown in FIG. 1 ) is positioned on the upper surface 12011 of the second flexible carrier 120, so that the alkali metal film faces the lower surface 130L of the flexible substrate stack 130 as the second flexible carrier 120 and the flexible substrate stack 130 are conveyed through the calendering unit 140. The alkali metal film is shown as the alkali metal film 242 in FIG. 2.

[0044] In some implementations, the alkali metal films on the first flexible carrier 110 and the second flexible carrier 120 can be formed of lithium metal, another alkali metal, for example, sodium, or an alloy including an alkali metal.

[0045] The transfer system 100 includes a flexible substrate supply hub 135. A supply roll 131 of the flexible substrate stack 130 is positioned on the flexible substrate supply hub 135. In some implementations, the flexible substrate stack 130 can be formed of one or more of copper, graphite, silicon, silicon graphite, silicon oxide graphite, silicon, metalized plastic, or other materials.

[0046] The transfer system 100 further includes the calendering unit 140. The calendering unit 140 includes a first calender roller 141 and a second calender roller 142. The first flexible carrier 110, the second flexible carrier 120, and the flexible substrate stack 130 are arranged to be conveyed along a path that extends between the first calender roller 141 and the second calender roller 142. The flexible substrate stack 130 is positioned between the first flexible carrier 110 and the second flexible carrier 120 when the first flexible carrier 110, the second flexible carrier 120, and the flexible substrate stack 130 are conveyed between the first calender roller 141 and the second calender roller 142. The calender rollers 141 , 142 exert a high amount of pressure on the flexible carriers 110, 120 and the flexible substrate stack 130 that causes the patterned alkali metal film on each of the flexible carriers 110, 120 to be transferred to the flexible substrate stack 130. In some implementations, a releaselayer is disposed on each of the flexible carriers 110, 120 between the corresponding flexible carrier 110, 120 and the alkali metal film on that flexible carrier. In some implementations, the release layer can be or include a polymer material that is capable of photoinduced depolymerization. In other implementations, the calendering unit 140 is replaced by a laser lift-off unit and a laser lift-off process is performed to transfer the patterned alkali metal film 241 , 242 from the flexible carrier 110, 120 to the flexible substrate stack 130.

[0047] The transfer system 100 includes a first flexible carrier pickup hub 116. A pickup roll 112 of the first flexible carrier 110 is positioned on the first flexible carrier pickup hub 116. The patterned alkali metal film is no longer on the first flexible carrier 110 when the first flexible carrier 110 is wound onto the first flexible carrier pickup hub 116 because the patterned alkali metal film previously on the first flexible carrier 110 is transferred onto the flexible substrate stack 130 by the calendering unit 140.

[0048] The transfer system 100 includes a second flexible carrier pickup hub 126. A pickup roll 122 of the second flexible carrier 120 is positioned on the second flexible carrier pickup hub 126. The patterned alkali metal film is no longer on the second flexible carrier 120 when the second flexible carrier 120 is wound onto the second flexible carrier pickup hub 126 because the patterned alkali metal film previously on the second flexible carrier 120 is transferred onto the flexible substrate stack 130 by the calendering unit 140.

[0049] The transfer system 100 includes a flexible substrate pickup hub 136. A pickup roll 132 of the flexible substrate stack 130 is positioned on the flexible substrate pickup hub 136. The flexible substrate stack 130 includes a patterned alkali metal film on each of the upper surface 130U and the lower surface 130L of the flexible substrate stack 130. The patterned alkali metal films are transferred from the respective flexible carriers 110, 120 onto the flexible substrate stack 130 by the calendering unit 140.

[0050] The transfer system 100 may further include a post-processing module 190. The post-processing module 190 is positioned downstream from the calendering unit 140 and upstream from the flexible substrate pickup hub 136. The post-processing module 190 is adapted to subject to the flexible substrate stack 130 including the patterned alkali metal film to additional processing. The additional processing performed by the post-processing module 190 can include one or more of plasmaetching to remove release layer residue present on the patterned alkali metal surface, passivation layer formation to protect the exposed alkali metal surface, postcalendering to flatten the exposed alkali metal surface, alkali metal reflow to flatten the exposed alkali metal surface, or slitting to cut the exposed portions of the flexible substrate stack to form electrode structures.

[0051] The transfer system 100 further includes a plurality of rollers 181-188. In some implementations, each of the rollers 181 -188 can be passive rollers. The rollers 181-188 can assist in applying proper tension to and assist in changing the direction of the flexible carriers 110, 120 and the flexible substrate stack 130 during the movement of each of the flexible carriers 110, 120 and the flexible substrate stack 130 through the different portions of the transfer system 100. Some of the rollers 181 - 188 can also assist in moving the flexible carriers 110, 120 closer to or further away from the flexible substrate stack 130. For example, the second and third rollers 182, 183 assist in bringing the flexible carriers 110, 120 into contact with the flexible substrate stack 130 before the flexible carriers 110, 120 and the flexible substrate stack 130 are conveyed through the calendering unit 140. Additionally, the fourth and fifth rollers 184, 185 provide a location at which tension can be applied to the flexible carriers 110, 120 to peel the flexible carriers 110, 120 away from the flexible substrate stack 130. In some implementations, one or more of the rollers 181 -188 can instead be a bar, such as metal bar, that can apply tension to the carrier or flexible substrate during the movement of the carrier or flexible substrate.

[0052] The transfer system 100 further includes a controller 105 for controlling processes performed by the transfer system 100. The controller 105 can be any type of controller used in an industrial setting, such as a programmable logic controller (PLC). The controller 105 includes a processor 107, a memory 106, and input / output (I / O) circuits 108. The controller 105 can further include one or more of the following components (not shown), such as one or more power supplies, clocks, communication components (e.g., network interface card), and user interfaces typically found in controllers for semiconductor equipment.

[0053] The memory 106 can include non-transitory memory. The non-transitory memory can be used to store the programs and settings described below. The memory 106 can include one or more readily available types of memory, such as readonly memory (ROM) (e.g., electrically erasable programmable read-only memory (EEPROM), flash memory, floppy disk, hard disk, or random access memory (RAM) (e.g., non-volatile random access memory (NVRAM).

[0054] The processor 107 is configured to execute various programs stored in the memory 106, such as a program configured to execute the method 600 described in reference to FIG. 7. During execution of these programs, the controller 105 can communicate to I / O devices through the I / O circuits 108. For example, during execution of these programs and communication through the I / O circuits 108, the controller 105 can control outputs (e.g., the actuators connected to the different hubs and the calendering unit 140). The memory 106 can further include various operational settings used to control the transfer system 100. For example, the settings can include speed settings for the actuators connected to the hubs as well as settings to control the laser lift-off unit 200 described herein.

[0055] The laser lift-off units 200, 300 may be positioned to pattern an exposed surface of an alkali metal, for example, the exposed surface of the alkali metal positioned on the first flexible carrier 110 or the second flexible carrier 120 prior to transfer of the alkali metal to the flexible substrate stack 130. Patterning the alkali metal via laser lift-off prior to transfer improves enable narrow-width roll production. For example, as shown in FIG. 1 , the laser lift-off units 200, 300 may be positioned downstream from the supply roll 111 of the first flexible carrier 110 and / or the supply roll 121 of the second flexible carrier 120 and upstream from the calendering unit 140.

[0056] FIG. 2 illustrates a side cross-sectional view of one example of a laser liftoff unit 200 in accordance with one or more implementations of the present disclosure. The laser lift-off unit 200 may be part of a transfer system, for example, the transfer systems described herein, or may be a stand-alone unit. The laser lift-off unit 200 is configured to expose portions of the alkali metal films 241 , 242 to electromagnetic energy to create an interface reaction with either a release layer, an interface layer, or both the release layer and the interface layer between the alkali metal films 241 , 242 and the flexible carriers 110, 120, for example, PET, to enable subsequent removal of the exposed portions of the alkali metal films 241 , 242 from the flexible carriers 110, 120 at the activated interface. The laser lift-off unit 200 includes a sacrificial film supply assembly 250 for supplying a sacrificial film 260 for removing theexposed portions of the alkali metal film 241 , 242. The laser lift-off unit 200 includes a laser source assembly 201 positioned to deliver electromagnetic energy toward the flexible carriers 110. The first flexible carrier 110, the second flexible carriers 120, having alkali metal films 241 , 242 formed thereon respectively are arranged to be conveyed along a path that travels by the laser source assembly 201 .

[0057] The laser source assembly 201 includes at least one of a laser source 202 and an optical source assembly 206. The laser source 202 is configured to generate a laser beam 230 and the optical source assembly 206 is configured to direct the laser beam 230 toward a back surface, for example, the upper surface 110U of the first flexible carrier 110 and the lower surface 120L of the second flexible carriers 120. In addition, the LLO process may be performed in a free-span orientation or a processing roller 255 or another backing surface may be positioned opposite the laser source assembly 201 as is shown in FIG. 2.

[0058] In one or more implementations, which can be combined with other implementations, the laser source 202 may be a solid-state laser, such as a diode- pumped solid-state laser having a fiber, a rod, or slab gain medium, configured to generate the laser beam 230. The laser beam 230 may be a continuous or pulsed laser beam. The laser fiber, rod, or slab may be formed of any suitable laser crystal materials, including neodymium-doped yttrium aluminum garnet (Nd:YAG; Nd:Y3AI5O12), ytterbium-doped YAG (Yb:YAG), neodymium-doped yttrium orthovanadate (Nd:YVO; Nd:YVO4), and alexandrite. In particular implementations, the laser rod or slab has a face pumping geometry. In particular implementations, the laser slab has an edge pumping geometry. Other types of lasers can be used such as a fiber laser or a gas laser. Suitable laser sources include but are not limited to an IR fiber laser, a UV laser, or a Green Laser.

[0059] In particular implementations, the laser source 202 is an infrared laser source configured to operate at infrared (IR) wavelengths for removing sections of alkali metal on alkali metal coated substrates. The laser source 202 may generate a pulsed laser beam 230. In some implementations described herein, frequency, pulse width, and pulse energy of the laser beam 230 generated by the laser source 202 are tunable (e.g., adjustable) depending on the material being removed, targeted lateral dimensions of the sections being removed, as well as a depth of the removal.Additionally, the movement speed of the laser beam 230, number of pulses, and beam profile and focused spot size may be tuned.

[0060] In any form, the laser beam 230 produced by the laser source 202 is projected (e.g., transmitted) towards the flexible carrier 110, 120 via the optical source assembly 206. The optical source assembly 206 is optically coupled with the laser source 202 and includes any suitable image projection devices for directing the laser beam 230 towards the flexible carrier 110, 120 for the laser lift-off patterning process. In particular implementations, the optical source assembly 206 includes a scanner 232, such as a single- or multi-axis large angle galvanometer optical scanner (i.e., galvanometer scanner). The term “galvanometer scanner” refers to any device that responds to an electronic signal from the controller 105 to change a projection or reflection angle of the laser beam 230 to sweep the laser beam 230 across the flexible carrier 110, 120. Scanner 232 may also be a polygon scanner, an electro-optic scanner, an acousto-optic, or a combination thereof. Utilization of the scanner 232 enables activation of multiple sections of the alkali metal film 241 , 242 on the flexible carrier 110, 120 via the laser lift-off patterning process, in addition to scanning of the laser beam 230 across a surface of the flexible carrier 110, 120 without mechanical translation of the flexible carrier 110, 120 itself. The scanner 232 may further include any suitable features to facilitate activation of the materials and structures described herein, such as digital servo feedback, low drift, fast dynamic response, and precise calibration capability.

[0061] In one or more implementations, which can be combined with other implementations, the optical source assembly 206 further includes one or more scan lenses 234 having a large field of view that encompasses the entirety of the flexible carrier 110, 120. In one or more implementations, which can be combined with other implementations, two or more scan lenses 234 may be utilized for laser removal of different types of materials, each scan lens of the scan lenses 234 specific to a wavelength range of the laser source 202. The scan lenses 234 may be telecentric lenses, F-theta lenses, or a combination thereof. During operation, the laser beam 230 projected by the optical source assembly 206 is directed towards the flexible carrier 110, 120.

[0062] The laser lift-off unit 200 further includes the sacrificial film supply assembly 250. The sacrificial film supply assembly 250 further includes the sacrificial film supply hub 251 for supplying the sacrificial film 260. A supply roll 261 of the sacrificial film 260 is positioned on the sacrificial film supply hub 251 . The sacrificial film 260 can be or include any suitable material for adhering to and removing the exposed portions of the alkali metal film 241 , 242. In some implementations, the sacrificial film 260 is formed from the same material, for example, PET, as the flexible carrier 110, 120. The sacrificial film supply assembly 250 further includes a sacrificial film pickup hub 252. A pickup roll 262 of the sacrificial film 260 having portions of alkali metal, for example, the portions of the alkali metal exposed to the laser energy, removed from the alkali metal film 241 , 242 during the LLO patterning process deposited thereon is positioned on the sacrificial film pickup hub 252.

[0063] The laser lift-off unit 200 further includes a plurality of rollers 281 -285. In some implementations, one or more of the rollers 281 -285 can be passive rollers. The rollers 281-285 can assist in applying proper tension to and assist in changing the direction of the flexible carrier 110, 120 and the sacrificial film 260 while traveling through the laser lift-off unit 200. For example, the first roller 281 and the fourth roller 284 provide locations at which additional tension can be applied to the sacrificial film 260. Some of the rollers 281 -285 can also assist in moving the flexible carriers 110, 120 closer to or further away from the sacrificial film 260. For example, in one or more implementations, one or more of the second roller 282, the third roller 283, and the fifth roller 285 function as nip rollers and assist in bringing the flexible carrier 110, 120 and the alkali metal film 241 , 242 into contact with the sacrificial film 260 while the flexible carrier 110, 120, the alkali metal film 241 , 242, and the sacrificial film 260 are conveyed past the laser source assembly 201 .

[0064] The laser lift-off unit 200 can further include a housing 215 disposed around an interior volume 208. The housing 215 can be used to maintain a separate environment in the interior volume 208 relative to the environment surrounding the laser lift-off unit 200. For example, the interior volume 208 can have different concentrations of gases as well as a different temperature and / or pressure relative to the environment surrounding the laser lift-off unit 200.

[0065] Referring to FIG. 2, in operation, the flexible carrier 110, 120 and the sacrificial film 260 are conveyed toward the laser source assembly 201 . As the flexible carrier 110, 120 and the sacrificial film 260 travel over the processing roller 255 the alkali metal film 241 , 242 is sandwiched in between the flexible carrier 110, 120 and the sacrificial film 260. The laser source assembly 201 provides laser energy to the alkali metal film 241 , 242 which is sandwiched between the flexible carrier 110, 120 and the sacrificial film 260 to create an interface reaction with either a release layer, an interface layer, or both the release layer and the interface layer between the alkali metal film 241 , 242 and the flexible carrier 110, 120 to enable subsequent removal of the exposed portions of the alkali metal film 241 , 242 by the sacrificial film 260 from the flexible carrier 110, 120 to pattern the alkali metal film 241 , 242 on the flexible carrier 110, 120.

[0066] FIG. 3 illustrates a side cross-sectional view of another example of a laser lift-off unit 300 in accordance with one or more implementations of the present disclosure. The laser lift-off unit 300 may be part of a transfer system, for example, the transfer systems described herein, or may be a stand-alone unit. The laser lift-off unit 300 is configured to expose portions of the alkali metal films 241 , 242 to electromagnetic energy to create an interface reaction with either a release layer, an interface layer, or both the release layer and the interface layer between the alkali metal films 241 , 242 and the flexible carriers 110, 120, for example, PET, to enable subsequent removal of the exposed portions of the alkali metal films 241 , 242 from the flexible carriers 110, 120 at the activated interface. The laser lift-off unit 300 includes a suction device 360 for removing the exposed portions of the alkali metal film 241 , 242. The laser lift-off unit 300 includes a laser source assembly 201 positioned to deliver electromagnetic energy toward the flexible carrier 110. The first flexible carrier 110, the second flexible carrier 120, having alkali metal films 241 , 242 formed thereon respectively are arranged to be conveyed along a path that travels by the laser source assembly 201 .

[0067] The suction device 360 is positioned adjacent to the alkali metal film 241 , 242 to removed exposed portions of alkali metal film. The suction device 360 can include a frame and / or a suction channel with openings for suctioning exposed portions of the alkali metal film 241 , 242. The frame can be a plate-, grid- or box-like structure including a suction channel. However, the frame may enclose a suctionvolume (cavity) different from a channel-like structure like cubical or other cavities. In one or more particular implementations, the suction device 360 includes a suction hood. The suction device 360 can be fluidly coupled with a vacuum source 390.

[0068] The laser source assembly 201 includes at least one of a laser source 202 and an optical source assembly 206. The laser source 202 is configured to generate a laser beam 230 and the optical source assembly 206 is configured to direct the laser beam 230 toward a back surface, for example, the upper surface 110U of the first flexible carrier 110 and the lower surface 120L of the second flexible carriers 120. In addition, in the implementation shown in FIG. 3, the LLO process is performed in a free-span orientation to accommodate the suction device 360 which is positioned opposite the laser source assembly 201 as is shown in FIG. 3.

[0069] The laser lift-off unit 300 further includes a plurality of rollers 381 -384. In some implementations, one or more of the rollers 381 -384 can be passive rollers. The rollers 381-384 can assist in applying proper tension to and assist in changing the direction of the flexible carrier 110, 120 while traveling through the laser lift-off unit 300. Some of the rollers 381 -384 can also assist in moving the flexible carriers 110, 120 closer to or further away from the suction device 360. For example, in one or more implementations, one or more of the second roller 282 and the third roller 283 and assist in bringing the flexible carrier 110, 120 and the alkali metal film 241 , 242 closer to the suction device 360 while the flexible carrier 110, 120 and the alkali metal film 241 , 242 are conveyed past the laser source assembly 201 .

[0070] The laser lift-off unit 200 can further include a housing 315 disposed around an interior volume 308. The housing 315 can be used to maintain a separate environment in the interior volume 308 relative to the environment surrounding the laser lift-off unit 300. For example, the interior volume 308 can have different concentrations of gases as well as a different temperature and / or pressure relative to the environment surrounding the laser lift-off unit 300.

[0071] Referring to FIG. 3, in operation, the flexible carrier 110, 120 having the alkali metal film 241 , 242 formed thereon is conveyed toward the laser source assembly 201. As the flexible carrier 110, 120 travels in between the second roller 382 and the third roller 383, the laser source assembly 201 provides laser energy to the alkali metal film 241 , 242 to create an interface reaction with either a release layer,an interface layer, or both the release layer and the interface layer between the alkali metal film 241 , 242 and the flexible carrier 110, 120 to enable subsequent removal of the exposed portions of the alkali metal film 241 , 242 by the suction device 360 from the flexible carrier 110, 120 to pattern the alkali metal film 241 , 242 on the flexible carrier 110, 120.

[0072] FIG. 4 illustrates a side cross-sectional view of one example of a laser liftoff system 400 in accordance with one or more implementations of the present disclosure. The laser lift-off system 400 includes an inline slitting unit 450 for cutting the flexible carrier having the patterned alkali metal film disposed thereon. The laser lift-off system 400 is configured to expose portions of the alkali metal films 241 , 242 to electromagnetic energy to create an interface reaction with either a release layer, an interface layer, or both the release layer and the interface layer between the alkali metal films 241 , 242 and the flexible carriers 110, 120, for example, PET, to enable subsequent removal of the exposed portions of the alkali metal films 241 , 242 from the flexible carriers 110, 120 at the activated interface. The laser lift-off system 400 includes the sacrificial film supply assembly 250 for supplying the sacrificial film 260 for removing the exposed portions of the alkali metal film 241 , 242. The laser lift-off system 400 further includes one or more laser source assemblies 201 a-c positioned to deliver electromagnetic energy toward the flexible carriers 110, 120. The first flexible carrier 110, the second flexible carriers 120, having alkali metal films 241 , 242 formed thereon respectively are arranged to be conveyed along a path that travels by the laser source assembly 201 a-c. Although three laser source assemblies 201 a-c are shown in FIG. 4, it should be understood that the laser lift-off system 400 can include any number of the laser source assembly 201 a-c, for example, the laser liftoff system 400 can include a single laser source assembly 201 a-c.

[0073] The laser lift-off system 400 further includes a flexible carrier supply hub 415. A supply roll 111 of the flexible carrier 110, 120 is positioned on the flexible carrier supply hub 415. An alkali metal film 241 , 242 is formed on or over the flexible carrier 110, 120 so that the alkali metal film faces an upper surface 261 U of the sacrificial film 260 as the flexible carrier 110, 120 and the sacrificial film 260 are conveyed passed the laser source assemblies 201 a-c.

[0074] The transfer system 100 further includes one or more flexible carrier pickup hubs 416a-b. A pickup roll 412a-b of the flexible carrier 110, 120 having the patterned alkali metal film formed thereover is positioned on the flexible carrier pickup hub 416a- b. The exposed portions of the alkali metal film are no longer on the flexible carrier 110, 120 when the flexible carrier 110, 120 is wound onto the flexible carrier pickup hub 416a-b because the exposed portions of the alkali metal film previously on the flexible carrier 110, 120 have been removed by the sacrificial film 260.

[0075] The laser source assembly 201 a-c is configured to generate and direct the laser beam 230 toward a back surface of the flexible carrier 110, 120. In addition, the LLO process may be performed in a free-span orientation or with a processing roller, for example, the processing roller 255, or another backing surface may be positioned opposite the laser source assembly 201 a-c as is shown in FIG. 4.

[0076] The laser lift-off system 400 further includes the sacrificial film supply assembly 250. The sacrificial film supply assembly 250 further includes the sacrificial film supply hub 251 for supplying the sacrificial film 260. The supply roll 261 of the sacrificial film 260 is positioned on the sacrificial film supply hub 251 . The sacrificial film supply assembly 250 further includes the sacrificial film pickup hub 252. The pickup roll 262 of the sacrificial film 260 having portions of alkali metal, for example, the portions of the alkali metal exposed to the laser energy, removed from the alkali metal film 241 , 242 during the LLO patterning process deposited thereon is positioned on the sacrificial film pickup hub 252. In other implementations, the sacrificial film supply assembly 250 is replaced with the suction device 360 as shown in FIG. 3.

[0077] The laser lift-off system 400 further includes the inline slitting unit 450. The inline slitting unit 450 is positioned downstream from the laser source assembly 201 a- c and upstream from the one or more flexible carrier pickup hubs 416a-b. The inline slitting assembly includes a blade assembly, a laser assembly, or combination of a blade assembly and a laser assembly for cutting the flexible carrier 110, 120. The blade assembly can be or include a blade, for example, a rotary blade for cutting the flexible carrier 110, 120.

[0078] The laser lift-off system 400 further includes a plurality of rollers 480-488. In some implementations, one or more of the rollers 480-488 can be passive rollers. The rollers 480-488 can assist in applying proper tension to and assist in changingthe direction of the flexible carrier 110, 120 and the sacrificial film 260 while traveling through the laser lift-off system 400. For example, the second roller 481 and the fifth roller 484 provide locations at which additional tension can be applied to the sacrificial film 260. Some of the rollers 480-488 can also assist in moving the flexible carriers 110, 120 closer to or further away from the sacrificial film 260. For example, in one or more implementations, one or more of the third roller 482, the fourth roller 483, and the sixth roller 485 function as nip rollers and assist in bringing the flexible carrier 110, 120 and the alkali metal film 241 , 242 into contact with the sacrificial film 260 while the flexible carrier 110, 120, the alkali metal film 241 , 242, and the sacrificial film 260 are conveyed past the laser source assembly 201 a-c.

[0079] In some implementations, one or more of the rollers 480-488 can instead be a bar, such as metal bar, that can apply tension to the carrier film or sacrificial film during the movement of the carrier film or sacrificial film.

[0080] The laser lift-off system 400 can further include a housing 417 disposed around an interior volume 408. The housing 417 can be used to maintain a separate environment in the interior volume 408 relative to the environment surrounding the laser lift-off system 400. For example, the interior volume 408 can have different concentrations of gases as well as a different temperature and / or pressure relative to the environment surrounding the laser lift-off system 400.

[0081] Referring to FIG. 4, in operation, the flexible carrier 110, 120 and the sacrificial film 260 are conveyed toward the laser source assembly 201 . As the flexible carrier 110, 120 and the sacrificial film 260 travel over the processing roller 255 the alkali metal film 241 , 242 is sandwiched in between the flexible carrier 110, 120 and the sacrificial film 260. The laser source assembly 201 provides laser energy to the alkali metal film 241 , 242 which is sandwiched between the flexible carrier 110, 120 and the sacrificial film 260 to create an interface reaction with either a release layer, an interface layer, or both the release layer and the interface layer between the alkali metal film 241 , 242 and the flexible carrier 110, 120 to enable subsequent removal of the exposed portions of the alkali metal film 241 , 242 by the sacrificial film 260 from the flexible carrier 110, 120 to pattern the alkali metal film 241 , 242 on the flexible carrier 110, 120. The flexible carrier 110, 120 having the patterned alkali metal film 241 , 242 travels through the inline slitting unit 450 where the flexible carrier 110, 120is cut into multiple rolls. After cutting, a first portion of the of the flexible carrier 110, 120 having the patterned alkali metal film is collected as the pickup roll 412a on the flexible carrier pickup hub 416a and a second portion of the flexible carrier 110, 120 having the patterned alkali metal film is collected as the pickup roll 412b on the flexible carrier pickup hub 416b. The pickup rolls 412a-b have a width that is narrower than the width of the supply roll 111.

[0082] FIG. 5 illustrates a side cross-sectional view of another example of a transfer system 500 in accordance with one or more implementations of the present disclosure. The transfer system 500 includes equipment for transferring pre-patterned alkali metal films on the first flexible carrier 110 and the second flexible carrier 120 to each side of the flexible substrate stack 130, so that the flexible substrate stack 130 with the patterned alkali metal films can be used as an electrode (e.g., anode) in a lithium-ion battery. The transfer system 500 includes a calendering unit 540 including one or more calendering rollers 541 , 542 for transferring the patterned alkali metal films on the flexible carriers 110, 120 to the flexible substrate stack 130. The prepatterned alkali metal films can be patterned by a laser lift-off unit, for example, any of the laser lift-off units 200, 300, 400 described herein.

[0083] The transfer system 500 includes a first flexible carrier supply hub 515. A supply roll 511 of the first flexible carrier 110 is positioned on the first flexible carrier supply hub 515. The supply roll 511 can be the pickup roll 412a-b. A patterned alkali metal film 241 is positioned on the lower surface 110L of the first flexible carrier 110, so that the patterned alkali metal film 241 faces the upper surface 130U of the flexible substrate stack 130 as the first flexible carrier 110 and the flexible substrate stack 130 are conveyed through the calendering rollers 541 , 542.

[0084] The transfer system 500 includes a second flexible carrier supply hub 525. A supply roll 521 of the second flexible carrier 120 is positioned on the second flexible carrier supply hub 525. The supply roll 521 can be the pickup roll 412a-b. A patterned alkali metal film 242 is positioned on the upper surface 12011 of the second flexible carrier 120, so that the alkali metal film faces the lower surface 130L of the flexible substrate stack 130 as the second flexible carrier 120 and the flexible substrate stack 130 are conveyed through the calendering unit 540.

[0085] The transfer system 500 includes a flexible substrate stack supply hub 535. A supply roll 131 of the flexible substrate stack 130 is positioned on the flexible substrate supply hub 135.

[0086] The transfer system 500 further includes the calendering unit 540. The calendering unit 540 includes one or more calendering rollers, for example, the first calender roller 541 and the second calender roller 542. The first flexible carrier 110, the second flexible carrier 120, and the flexible substrate stack 130 are arranged to be conveyed along a path that extends between through the calendering unit 540. The flexible substrate stack 130 is positioned between the first flexible carrier 110 and the second flexible carrier 120 when the first flexible carrier 110, the second flexible carrier 120, and the flexible substrate stack 130 are conveyed between the first calender roller 541 and the second calender roller 542. The calender rollers 541 , 542 exert a high amount of pressure on the flexible carriers 110, 120 and the flexible substrate stack 130 that causes the patterned alkali metal film 241 , 242 on each of the flexible carriers 110, 120 to be transferred to the flexible substrate stack 130. In some implementations, a release layer is disposed on each of the flexible carriers 110, 120 between the corresponding flexible carrier 110, 120 and the patterned alkali metal film on that flexible carrier.

[0087] The transfer system 500 includes a first flexible carrier pickup hub 516. A pickup roll 512 of the first flexible carrier 110 is positioned on the first flexible carrier pickup hub 516. The patterned alkali metal film 241 is no longer on the first flexible carrier 110 when the first flexible carrier 110 is wound onto the first flexible carrier pickup hub 516 because the patterned alkali metal film 241 previously on the first flexible carrier 110 is transferred onto the flexible substrate stack 130 by the calendering rollers 541 , 542.

[0088] The transfer system 500 includes a second flexible carrier pickup hub 526. A pickup roll 522 of the second flexible carrier 120 is positioned on the second flexible carrier pickup hub 526. The patterned alkali metal film 242 is no longer on the second flexible carrier 120 when the second flexible carrier 120 is wound onto the second flexible carrier pickup hub 526 because the patterned alkali metal film 242 previously on the second flexible carrier 120 is transferred onto the flexible substrate stack 130 by the calendering rollers 541 , 542.

[0089] The transfer system 500 includes a flexible substrate stack pickup hub 536. A pickup roll 132 of the flexible substrate stack 130 is positioned on the flexible substrate stack pickup hub 536. The flexible substrate stack 130 includes a patterned alkali metal film 241 , 242 on each of the upper surface 13011 and the lower surface 130L of the flexible substrate stack 130. The patterned alkali metal films 241 , 242 are transferred from the respective flexible carriers 110, 120 onto the flexible substrate stack 130 by the calendering rollers 541 , 542.

[0090] The transfer system 500 further includes a plurality of rollers 581-584. In some implementations, each of the rollers 581 -584 can be passive rollers. The rollers 581-584 can assist in applying proper tension to and assist in changing the direction of the flexible carriers 110, 120 and the flexible substrate stack 130 during the movement of each of the flexible carriers 110, 120 and the flexible substrate stack 130 through the different portions of the transfer system 500. Some of the rollers 581 - 584 can also assist in moving the flexible carriers 110, 120 closer to or further away from the flexible substrate stack 130. For example, the first roller 581 can assist in bringing the flexible carriers 110, 120 into contact with the flexible substrate stack 130 before the flexible carriers 110, 120 and the flexible substrate stack 130 are conveyed through the calendering unit 540. Additionally, the second and third rollers 582, 583 provide a location at which tension can be applied to the flexible carriers 110, 120 to peel the flexible carriers 110, 120 away from the flexible substrate stack 130. In some implementations, one or more of the rollers 581-584 can instead be a bar, such as metal bar, that can apply tension to the carrier or flexible substrate during the movement of the carrier or flexible substrate.

[0091] The transfer system 500 can further include a housing 517 disposed around an interior volume 508. The housing 517 can be used to maintain a separate environment in the interior volume 508 relative to the environment surrounding the transfer system 500. For example, the interior volume 508 can have different concentrations of gases as well as a different temperature and / or pressure relative to the environment surrounding the transfer system 500.

[0092] The transfer system 500 can further include a pre-processing module 560. The pre-processing module 560 can be positioned downstream from the flexible substrate stack supply hub 535 and upstream from the calendering rollers 541 , 542.The pre-processing module 560 provides a surface treatment to the substrate stack 130, which enhances alkali metal bonding with the substrate stack 130. The surface treatment can include exposing the surface of the substrate stack 130 to atmospheric plasma or laser treatment.

[0093] The transfer system 500 may further include a post-processing module 570. The post-processing module 570 is positioned downstream from the calendering rollers 541 , 542 and upstream from the flexible substrate pickup hub 536. The postprocessing module 570 is adapted to subject to the flexible substrate stack 130 including the patterned alkali metal film to additional processing. The additional processing performed by the post-processing module 570 can include one or more of plasma etching to remove release layer residue present on the patterned alkali metal surface, passivation layer formation to protect the exposed alkali metal surface, postcalendering to flatten the exposed alkali metal surface, alkali metal reflow to flatten the exposed alkali metal surface, or slitting to cut the exposed portions of the flexible substrate stack 130 to form electrode structures.

[0094] FIG. 6 illustrates an exemplary flow chart of a method 600 in accordance with one or more implementations of the present disclosure. FIGS. 7A-7F illustrate side views of various stages of manufacturing an anode structure according to the method 600 of FIG. 6 in accordance with one or more implementations of the present disclosure. FIGS. 8A-8E illustrate top views of various stages of manufacturing an anode structure according to the method 600 of FIG. 6 in accordance with one or more implementations of the present disclosure. Although FIGS. 7A-7F and 8A-8E are described in relation to the method 600, it will be appreciated that the structures disclosed in FIGS. 7A-7F and 8A-8E are not limited to the method 600, but instead may stand alone as structures independent of the method 600. Similarly, although the method 600 is described in relation to FIGS. 7A-7F and 8A-8E, it will be appreciated that the method 600 is not limited to the structures disclosed in FIGS. 7A- 7F and 8A-8E but instead may stand alone independent of the structures disclosed in FIGS. 7A-7F and 8A-8E. It should be understood that FIGS. 7A-7F and 8A-8E illustrate only partial schematic views of the energy storage device structure 700, and the energy storage device structure 700 may contain any number of additional layers and / or additional materials common to energy storage devices, which are not shown for the sake of brevity. It should also be noted that although the method 600 illustratedin FIG. 6 is described sequentially, other process sequences that include one or more operations that have been omitted and / or added, and / or have been rearranged in another desirable order, fall within the scope of the implementations of the disclosure provided herein. The method 600 may be performed using any of the aforementioned laser lift-off units 200, 300, and 400 and flexible substrate transfer systems 100 and 500.

[0095] Referring to FIG. 7A and 8A, at operation 610, a flexible carrier 110 having an alkali metal film 241 formed thereon and a sacrificial film 260 are conveyed toward a laser source, for example, the laser source assembly 201 . The flexible carrier 110 can include or be a polymer substrate as described. The sacrificial film 260 can be or include any suitable material for adhering to and removing the exposed portions 241 E of the alkali metal film 241 . In some implementations, the sacrificial film 260 is formed from the same material, for example, PET, as the flexible carrier 110.

[0096] The flexible carrier 110 can further include a release film respectively. The release film is disposed in between the flexible carrier 110 and the alkali metal film 241 . The release film assists in removal of the alkali metal film 241 from the underlying polymer substrate. In one or more implementations, the release film can be or include a polymer material that is capable of photoinduced depolymerization. In one or more implementations, the polymer material can be or include a poly(olefin sulfone) material capable of photoinduced depolymerization. The poly(olefin sulfone) may be combined with photobase generators (PBGs). The poly(olefin sulfone) can be doped with a photosensitizer, for example, pyridine N-oxide. The depolymerization process can be induced by, for example, X-rays, electron-beam irradiation, or low-energy irradiation. Suitable poly(olefin sulfone) materials include poly(1 -butene sulfone) (PBS), poly(1 - pentane sulfone) (PPS), poly(1 -hexane sulfone) (PHS), poly( 1 -octene sulfone) (POS), poly(cyclopentene sulfone), poly(2-methyl-1 -butene sulfone) (PMBS), poly(2-methyl- 1 -pentene sulfone) (PMPS), poly(2-methyl 1 -hexene sulfone) (PMHS), poly(2-methyl- 1 -nonene sulfone) (PMNS), poly(cyclohexene sulfone), or a combination thereof. In other implementations, the release film can be or include one or more of fluorocarbons, silicone, latex, AIOx, LiF, AIOOH, Ag, AgF, Bi, or Sn. The release layer can also be an engineered polymer tailored for high laser absorption. Optionally, the laser absorbing material can also be pattern coated on top of the plastic substrate withor without a release layer for areas of alkali metal or alloy to be transferred vs nontransferred to create targeted pattern transfer.

[0097] Referring to FIG. 7B, at operation 620, portions of the alkali metal film 241 are exposed to laser lift-off process to pattern the alkali metal film 241 The patterned alkali metal film 241 including exposed portions 241 E of the alkali metal film 241 and unexposed portions 241 U of the alkali metal film 241 . The laser lift-off process of operation 620 includes exposing the flexible carrier 110 having the alkali metal film 241 formed thereon to laser energy, for example, the laser energy supplied by the laser source assembly 201 . In one or more implementations, during the laser lift-off process of operation 620, a laser beam provided by the laser source assembly 201 is directed through a backside of the flexible carrier 110 respectively to activate the interface of the alkali metal film 241 and the flexible carrier 110, for example, the Li- PET interface. As is shown in FIG. 7B, the laser beam 230 can be directed through the backside of the first flexible carrier 110, for example, from the plastic containing substrate or PET side of the first flexible carrier 110. Exposure to the laser energy can activate not only the alkali metal film 241 but also a portion of the first flexible carrier 110. For example, exposure to the laser energy can activate a portion of the flexible carrier 110, for example, the release film, a portion of the flexible carrier 110, or both a portion of the flexible carrier 110 and the release film. In one or more implementations, the activated portion can correspond to a void volume. Exposure to the laser energy can induce an alkali metal transfer process creating a void volume between the exposed portions 241 E of the alkali metal film 241 and the flexible carrier 110. The void volume can make separation of the exposed portions 241 E of the alkali metal film 241 and the flexible carrier 110 easier during transfer of the exposed portions 241 E of the alkali metal film 241 from the flexible carrier 110, 120 to the sacrificial film 260. The void volume can be formed in a pattern such that the exposed portions 241 E of the alkali metal film 241 that are above the patterned void volume can be more easily removed thus forming a pattern when transferred onto the flexible substrate stack 130. In addition, exposure to the laser beam 230 can be used to pattern the alkali metal film 241 such that a precise pattern of the alkali metal film 241 can be transferred from the flexible carrier 110 to the sacrificial film 260.

[0098] In some implementations, which can be combined with other implementations, the mechanism of void formation during the laser lift-off process isbelieved to be a combination of plasma generation by photoionization with recombination of sublimation and lithium.

[0099] Referring to FIG. 7C and 8B, at operation 630, the exposed portions 241 E of the alkali metal film 241 are removed from the flexible carrier 110 with the sacrificial film 260. The exposed portions 241 E may be removed by contacting the exposed portions 241 E of the alkali metal film 241 with the sacrificial film prior to, during, or after operation 620. Referring to FIG. 8B, after removal of the exposed portions 241 E of the alkali metal films, the unexposed portions 241 U of the alkali metal film 241 remain on the flexible carrier 110. The unexposed portions 241 U define parallel lanes 741 on the flexible carrier 110 that are free or substantially free from the alkali metal film 241 . The parallel lanes 741 functions as cutting lanes in subsequent operations that allow cutting without alkali metal buildup on the cutting implement.

[0100] Referring to FIG. 7D and 8C, at operation 640, the patterned alkali metal film 241 is transferred from the flexible carrier 110 to the flexible substrate stack 130. The transfer operation performed during operation 640 can include a calendering process, a laser lift-off process, or both a calendering and laser lift-off process. For example, a surface of the unexposed portions 241 U of the alkali metal film 241 is contacted to a first surface of the flexible substrate stack 130. In some implementations, where the flexible substrate stack 130 only includes a current collector substrate, the unexposed portions 241 U of the alkali metal film 241 contact the current collector substrate. In some implementations, where the flexible substrate stack 130 includes an anode film, the surface of the alkali metal film 241 contacts the anode film to pre-lithiate the anode material.

[0101] Referring to FIG. 7E and 8D, at operation 650, the flexible carrier 110 is peeled away from the flexible substrate stack 130, for example, as the flexible carriers 110, 120 are conveyed past the rollers 582, 583 as shown in FIG. 5. In some implementations where the release film is present, the release film is removed with the flexible carrier 110. The flexible carrier 110 is then conveyed to the respective pickup hub, for example, the pickup hub 116.

[0102] Referring to FIG. 7F and 8E, at operation 660, the flexible substrate stack 130 having the patterned alkali metal film 241 is cut along the parallel lanes 741 form individual electrode structures 841 a-d. The parallel lanes 741 create cutting lanes onthe flexible substrate stack 130 that are free or substantially free from alkali metal allowing the cutting blade or other cutting implement to cut the flexible substrate stack 130 along the cutting lanes without alkali metal build-up on the cutting blade. In one or more implementations, an IR fiber laser is used to activate the flexible support layer- Li interface, for example, the PET-Li interface, from the flexible support layer side.

[0103] FIG. 9A illustrates a top views of a flexible carrier stack 910 formed in accordance with one or more implementations of the present disclosure. The flexible carrier stack 910 includes the flexible carrier 110 having a patterned alkali metal film 241 formed thereover. The patterned alkali metal film 241 includes the parallel lanes 741 , which are parallel to the length of the flexible carrier 110 and parallel to the machine direction 940 or travel direction of the flexible carrier 110.

[0104] FIG. 9B illustrates a top views of a flexible carrier stack 920 formed in accordance with one or more implementations of the present disclosure. The flexible carrier stack 920 includes the flexible carrier 110 having a patterned alkali metal film 241 formed thereover. The patterned alkali metal film 241 includes the perpendicular lanes 941 , which are parallel to the width of the flexible carrier 110 and perpendicular to the machine direction 940 or travel direction of the flexible carrier 110.

[0105] FIG. 9C illustrates a top views of a flexible carrier stack 930 formed in accordance with one or more implementations of the present disclosure. The flexible carrier stack 930 includes the flexible carrier 110 having a patterned alkali metal film 241 formed thereover. The patterned alkali metal film 241 includes perpendicular lanes 941 , which are parallel to the width of the flexible carrier 110 and perpendicular to the machine direction 940 or travel direction of the flexible carrier 110. The patterned alkali metal film 241 includes the parallel lanes 741 , which are parallel to the length of the flexible carrier 110 and parallel to the machine direction 940 or travel direction of the flexible carrier 110.

[0106] The previously described implementations of the present disclosure have many advantages. However, the present disclosure does not require that all the advantageous features and all the advantages need to be incorporated into every implementation of the present disclosure. The LLO patterning process and systems described minimize equipment investment costs and factory space occupancy by maximizing the efficiency of wider-width lithium production. The LLO patterningprocess and systems described provides a convenient and scalable alkali metal anode manufacturing system. In addition, the LLO patterning process and systems described can achieve the benefits of no need to slit the web for pattern transfer, simplifies the traditional SIDT process, achieves a faster transfer rate, simplified transfer tool architecture, and a small tool footprint. In addition, the LLO patterning process is safe and industrially scalable for high-volume manufacturing.

[0107] In the Summary and in the Detailed Description the claims below, and in the accompanying drawings, reference is made to particular features (including method operations) of the present disclosure. It is to be understood that the disclosure in the specification includes all possible combinations of such particular features. For example, where a particular feature is disclosed in the context of a particular aspect or implementation of the present disclosure, or a particular claim, that feature can also be used, to the extent possible in combination with and / or in the context of other particular aspects and implementations of the present disclosure, and in the present disclosure generally.

[0108] The term “comprising,” “including” and “having” and grammatical equivalents thereof are used herein to mean that other components, ingredients, operations, etc. are optionally present. For example, an article “comprising” (or “which comprises”) components A, B, and C can consist of (i.e. , contain only) components A, B, and C, or can contain not only components A, B, and C but also one or more other components. In addition, whenever a composition, an element or a group of elements is preceded with the transitional phrase “comprising” or grammatical equivalents thereof, it is understood that it is contemplated that the same composition or group of elements may be preceded with transitional phrases “consisting essentially of,” “consisting of,” “selected from the group of consisting of,” or “is” preceding the recitation of the composition, element, or elements and vice versa.

[0109] Where reference is made herein to a method comprising two or more defined operations, the defined operations can be carried out in any order or simultaneously (except where the context excludes that possibility), and the method can include one or more other operations which are carried out before any of the defined operations, between two of the defined operations, or after all of the defined operations (except where the context excludes that possibility).

[0110] When, in this specification, a range is given as “(a first number) to (a second number)” or “(a first number)-(a second number),” this means a range whose lower limit is the first number and whose upper limit is the second number. For example, 25 to 100 mm means a range whose lower limit is 25 mm, and whose upper limit is 100 mm.

[0111] Implementations and all of the functional operations described in this specification can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structural means disclosed in this specification and structural equivalents thereof, or in combinations of them. Implementations described herein can be implemented as one or more non-transitory computer program products, i.e. , one or more computer programs tangibly embodied in a machine readable storage device, for execution by, or to control the operation of, data processing apparatus, e.g., a programmable processor, a computer, or multiple processors or computers.

[0112] The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0113] The term “data processing apparatus” encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer.

[0114] Computer readable media suitable for storing computer program instructions and data include all forms of nonvolatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM,EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0115] When introducing elements of the present disclosure or exemplary aspects or implementation(s) thereof, the articles “a,” “an,” “the” and “said” are intended to mean that there are one or more of the elements.

[0116] While the foregoing is directed to implementations of the present disclosure, other and further implementations of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

What is claimed is:

1. A flexible substrate processing system for forming an energy storage device, comprising: a first supply hub for supplying a flexible carrier film having an alkali metal film formed thereover; a second supply hub for supplying a sacrificial film; a first pickup hub for collecting the flexible carrier film having a patterned alkali metal film formed thereover, the patterned alkali metal film formed by exposing portions of the alkali metal film to laser energy, the patterned alkali metal film comprising unexposed portions of the alkali metal film; a second pickup hub for collecting the sacrificial film, the sacrificial film having the exposed portions of the alkali metal film formed thereover; and a laser lift-off unit positioned downstream from the first supply hub and the second supply hub and upstream from the first pickup hub and the second pickup hub, the laser lift-off unit, comprising: a laser source configured to generate laser energy, the laser energy directed toward the alkali metal film; and an optical scanner configured to direct the laser energy toward the alkali metal film.

2. The flexible substrate processing system of claim 1 , further comprising: a pair of rollers positioned downstream of the first supply hub and the second supply hub and upstream of the laser source, the pair of rollers positioned to contact the alkali metal film to the sacrificial film.

3. The flexible substrate processing system of claim 2, wherein the pair of rollers comprise at least one nip roller.

4. The flexible substrate processing system of claim 2 wherein the pair of rollers comprise at least one calender roller.

5. The flexible substrate processing system of claim 1 , wherein the laser source is selected from an infrared (IR) fiber laser, an ultraviolet (UV) laser, or a Green Laser.

6. The flexible substrate processing system of claim 1 , wherein the optical scanner is a single- or multi-axis large angle galvanometer optical scanner.

7. The flexible substrate processing system of claim 1 , wherein the optical scanner is a polygon scanner, an electro-optic scanner, an acousto-optic, or a combination thereof.

8. The flexible substrate processing system of claim 1 , further comprising: a passivation unit positioned downstream from the laser lift-off unit and upstream from the second pickup hub, the passivation unit positioned to passivate the alkali metal film formed on the flexible carrier film.

9. The flexible substrate processing system of claim 1 , further comprising: an inline slitting assembly comprising a blade for cutting the flexible carrier film, the inline slitting assembly positioned downstream from the laser lift-off unit and upstream from the first pickup hub.

10. The flexible substrate processing system of claim 1 , further comprising: a third supply hub for supplying a flexible substrate film stack; and a third pickup hub for collecting the flexible substrate film stack having the patterned alkali metal film formed thereon.

11. A flexible substrate processing system for forming an energy storage device, comprising: a laser lift-off unit, comprising: a laser source configured to generate laser energy, the laser energy directed toward a first surface of a flexible carrier film having an alkali metal film formed thereover; and an optical scanner configured to direct the laser energy toward the first surface of the flexible carrier film; anda system controller configured to cause the laser lift-off unit to perform a process, comprising: conveying a flexible carrier film stack comprising the flexible carrier film having the alkali metal film formed thereover from a supply hub toward a pickup hub; contacting the flexible carrier film stack with a sacrificial film, wherein the alkali metal film contacts the sacrificial film; exposing portions of the alkali metal film to the laser energy to pattern the alkali metal film; and removing the sacrificial film from the flexible carrier film stack to form the patterned alkali metal film on the flexible carrier film stack, the patterned alkali metal film comprising unexposed portions of the alkali metal film and the sacrificial film having the exposed portions of the alkali metal film formed thereon.

12. The flexible substrate processing system of claim 11 , wherein the laser source is selected from an infrared (IR) fiber laser, an ultraviolet (UV) laser, or a Green Laser.

13. The flexible substrate processing system of claim 11 , wherein the optical scanner is a single- or multi-axis large angle galvanometer optical scanner.

14. The flexible substrate processing system of claim 11 , further comprising: a pair of rollers positioned upstream of the laser source, the pair of rollers contacting the flexible carrier film stack with the sacrificial film.

15. The flexible substrate processing system of claim 14, wherein the pair of rollers comprise at least one nip roller.

16. The flexible substrate processing apparatus of claim 14, wherein the pair of rollers comprise at least one calender roller.

17. A method of forming a film stack for an energy storage device, comprising: conveying a flexible carrier film stack comprising a flexible carrier film having an alkali metal film formed thereover from a supply hub toward a pickup hub; contacting the flexible carrier film stack with a sacrificial film, wherein the alkali metal film contacts the sacrificial film;exposing portions of the alkali metal film to the laser energy to separate the exposed portions of the alkali metal film from the flexible carrier film; and removing the sacrificial film and the exposed portions of the alkali metal film from the flexible carrier film stack to form a patterned alkali metal film on the flexible carrier film, the sacrificial film having the exposed portions of the alkali metal film formed thereon.

18. The method of claim 17, wherein the laser energy is directed through a backside of the flexible carrier film.

19. The method of claim 17, wherein exposing the flexible carrier film stack to laser energy creates a void volume between the alkali metal film and the flexible carrier film stack.

20. The method of claim 17, wherein the flexible carrier film stack further comprises a release layer disposed between the flexible carrier film and the alkali metal film, the release layer is capable of photoinduced depolymerization.

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