Seed layer for lithium transfer and passivation

Abstract

Embodiments of the present disclosure generally relate to film stacks for electronic devices and methods of forming film stacks including lithium anodes and pre-lithiated anodes for energy storage devices. The method includes forming a seed layer over a flexible support layer and depositing a lithium metal layer on the seed layer. The method further includes laminating a lithium metal layer onto the flexible receiving substrate and separating the lithium metal layer from the flexible support layer. The seed layer acts as a release layer for the lithium metal layer. At least a portion of the seed layer is transferred with the lithium metal layer to provide passivation for the lithium metal layer.

Description

Technical Field

[0001] The implementation of this disclosure generally relates to film stacks for electronic devices and methods for forming film stacks. Background Technology

[0002] High-capacity electrochemical energy storage devices, such as lithium-ion (Li-ion) batteries, are being used in a growing number of applications, including portable electronics, medical, transportation, grid-connected large-scale energy storage, renewable energy storage, and uninterruptible power supplies (UPS).

[0003] The lithium metal layer plays a crucial role in the development of Li-ion batteries. Lithium is an alkali metal. Similar to its heavy element homologues in the first periodic table, lithium is characterized by its strong reactivity with a wide variety of substances. Lithium reacts violently with water, alcohols, and other substances containing protonated hydrogen, often resulting in ignition. Lithium is unstable in air and reacts with oxygen, nitrogen, and carbon dioxide. Therefore, due to its highly reactive nature, lithium is typically handled in an inert gas atmosphere (a rare gas, such as argon). Consequently, lithium presents several challenges in handling, storage, and transportation.

[0004] Therefore, there is a need in the art for an improved method for transferring lithium metal layers to form film stacks. Summary of the Invention

[0005] In one embodiment, a method is provided for forming a seed layer over a flexible support layer. The method includes depositing a lithium metal layer on the seed layer, laminating the lithium metal layer onto a flexible receiving substrate, and separating the lithium metal layer from the flexible support layer to transfer the lithium metal layer to the receiving substrate. During the transfer of the lithium metal layer, at least a portion of the seed layer is transferred to the receiving substrate along with the lithium metal layer to provide passivation for the lithium metal layer.

[0006] In another embodiment, a method for forming a film stack for an energy storage device is provided. The method includes depositing a flexible support layer in a vacuum environment and forming a seed layer over the flexible support layer. The seed layer comprises LiF, Li₂CO₃, Ag, Bi, Sn, Ag+LiF, Bi+LiF, Sn+LiF, AgF, CxFy, or combinations thereof. The method further includes depositing a lithium metal layer on the seed layer, laminating the lithium metal layer to a flexible receiving substrate, and transferring the lithium metal layer from the flexible support layer to the flexible receiving substrate to form the film stack. The seed layer facilitates the release of the lithium metal layer from the flexible support layer, and at least a portion of the seed layer is transferred to the flexible receiving substrate along with the lithium metal layer.

[0007] In a further embodiment, a film stack for an energy storage device is provided. The film stack includes a flexible receiving substrate, a lithium metal layer disposed on the flexible receiving substrate, and a seed layer disposed above at least a portion of the lithium metal layer. The seed layer provides passivation for a portion of the lithium metal layer disposed between the seed layer and the flexible receiving substrate. The lithium metal layer and the seed layer also transfer from a flexible support layer to the flexible receiving substrate, wherein the seed layer acts as a release layer for separating the lithium metal layer from the flexible support layer. Attached Figure Description

[0008] To gain a more detailed understanding of the features described above in this disclosure, a more specific description of the disclosure, which has been briefly summarized above, can be obtained by referring to the implementations, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only exemplary implementations and should not be construed as limiting the scope of this disclosure, and other equivalent implementations are permitted.

[0009] Figure 1 A flowchart illustrating selected operations of a method for forming an energy storage device according to one or more implementations of this disclosure is shown.

[0010] Figures 2A to 2G The disclosure illustrates one or more implementations of this method. Figure 1 The method is used to create views of each stage of an energy storage device.

[0011] Figure 3 A flowchart illustrating selected operations of a method for forming an energy storage device according to one or more implementations of this disclosure is shown.

[0012] Figures 4A to 4E The disclosure illustrates one or more implementations of this method. Figure 3 The method is used to create views of each stage of an energy storage device.

[0013] Figure 5 This illustrates one or more implementations of the present disclosure in a lamination transfer apparatus according to... Figure 3 A schematic diagram of a method for manufacturing energy storage devices.

[0014] Figure 6 A schematic diagram of a flexible substrate coating apparatus according to one or more implementations of the present disclosure is shown.

[0015] Figure 7 A schematic diagram of a lamination transfer apparatus according to one or more implementations of the present disclosure is shown.

[0016] For ease of understanding, the same reference numerals are used as much as possible to indicate common elements in the figures. It is conceivable that elements and features of one implementation may be advantageously incorporated into other implementations without further description. Detailed Implementation

[0017] This disclosure generally relates to a process for transferring metal layers using a release layer. Specifically, it relates to a method using a deposited seed layer configured to act as a release layer and a surface passivation layer during the formation of an anolyte film stack.

[0018] Transferring lithium metal layers onto a substrate is a crucial process in the microfabrication of microelectronic devices and energy storage devices. Substrate Independent Direct Transfer (SIDT) is a method for forming an anode film stack or for pre-lithiating anode material already formed on a current collector by transferring one or more layers, including an alkali metal layer (such as a lithium metal layer), to a substrate stack (e.g., a current collector in an implementation where lithium metal is used as the anode). The formed anode material may include, but is not limited to, graphite, silicon, graphite silicon, graphite silica, silicon, or combinations thereof. The current collector may include, or be metallized plastic, copper, or combinations thereof. In the SIDT process, lithium is formed over a flexible support layer stack composed of one or more materials, such as a polymer substrate, for example, polyethylene terephthalate (PET), paper, or combinations thereof. The material formed on the flexible support layer stack is directly transferred / laminated onto the substrate stack. The substrate stack may include, or be a current collector, a current collector having anode material formed thereon, a metallized plastic substrate, a separator, or a metallized plastic substrate having lithium formed thereon.

[0019] Conventional methods for transferring material formed on flexible support layer stacks typically involve using a release layer formed between the alkali metal layer and the flexible support layer stack. The release layer enables the transfer of lithium and other materials from the flexible support layer stack to a current collector or anode material (if already present). Such conventional release layers are typically pre-fabricated on the flexible support layer stack and vary in thickness, release pressure, particle size, and pinholes. Variations and uncontrollable properties of the release layer can lead to process variations during SIDT. Therefore, after SIDT, trace amounts of material from the release layer may remain on the lithium surface of the formed film stack.

[0020] However, release layer materials are often incompatible with end-use applications, such as electrochemical devices. For example, the chemistry of the release layer may be incompatible with the end device (e.g., a battery) and may hinder the transport of ions or electrons. That is, the chemistry of the release layer may lead to an increase in battery impedance between the anode and separator interface, which is generally undesirable as it can affect the overall battery performance. Furthermore, undesirable reactions of the release layer with gases (e.g., H2O, O2, N2, etc.) during handling, transportation, and subsequent integration may affect device integration.

[0021] The following describes a method for depositing a seed layer, which serves both as a release layer for the transferred lithium metal layer in SIDT and as a surface passivation layer after the lithium metal layer transfer. Figure 1 The SIDT process of this disclosure is described in the implementation details. In one or more implementations that can be combined with other implementations, a seed layer is deposited on a flexible support layer in a vacuum chamber prior to the formation of the lithium metal layer. The seed layer enables the release layer to have consistent quality, engineering control, and is tailored to act as a surface passivation layer during the formation of the anolyte film stack. Depositing the seed layer in a vacuum also provides the engineering opportunity to develop a high-quality original interface layer and form the anolyte film stack without compromising the vacuum.

[0022] One or more implementations of this disclosure also provide improved interface control for vacuum deposition without disrupting the vacuum. The method can be incorporated into roll-to-roll tools and used as... Figure 3 In the roll-to-roll process described in the implementation method, the roll-to-roll fabrication of the interface layer provides a solution for high-volume manufacturing, which includes substrate-independent deposition and transfer (SIDT) of lithium anode film stacks. High-quality lithium metal can be deposited on the seed layer just before lamination transfer to retain the highest quality material in the film stack.

[0023] It should be noted that while there are no specific substrates on which some of the implementations described herein can be practiced, it is particularly advantageous to practice these implementations on flexible substrates, including, for example, roll-based substrates, panels, and discrete sheets. Flexible substrates may also be in the form of foils, films, or sheets.

[0024] It should also be noted that the flexible substrate or roll material used in the implementations described herein is typically characterized by its bendability. The term "roll material" may be used synonymously with the terms "strip," "flexible substrate," or "flexible conductive substrate." For example, the roll material described in the implementations herein may be a polymer material.

[0025] Figure 1A flowchart is shown of a method 100 for manufacturing an energy storage device according to one or more implementations of the present disclosure. Figures 2A to 2G It is based on Figure 1 The method 100 provides views of the various stages of fabricating an energy storage device. Method 100 describes forming a SIDT stack 255 on a flexible support layer 210, and then transferring the SIDT stack 255 to a receiving substrate 260 to form an anode film stack 265. Although... Figures 2A to 2G It is about the description of method 100, but it should be understood that... Figures 2A to 2G The structure disclosed herein is not limited to method 100, but can exist independently as a structure independent of method 100. Similarly, although method 100 is about... Figures 2A to 2G As described, but it should be understood that Method 100 is not limited to Figures 2A to 2G The structure is not publicly available, but can be independent of... Figures 2A to 2G It exists based on the publicly disclosed structure.

[0026] It should be understood Figures 2A to 2G Only a partial schematic diagram of the energy storage device is shown, and the energy storage device may contain any number of additional layers and / or additional materials common to energy storage devices; for the sake of brevity, these additional layers and / or additional materials are not illustrated. It should also be noted that, although... Figure 1 The method 100 shown herein is described in sequence, but other process sequences including one or more operations that have been omitted and / or added and / or rearranged in another desired order fall within the scope of the implementation of this disclosure provided herein.

[0027] refer to Figure 2A At operation 101, a flexible support layer 210 of a flexible support layer stack 200 is provided. The flexible support layer 210 has a front side 210f (also referred to as a front surface) and a back side 210b (also referred to as a back surface) opposite to the front side 210f. The flexible support layer 210 may contain any suitable material compatible with the target processing conditions.

[0028] In some implementations, the flexible support layer comprises multiple sublayers. In one or more implementations that can be combined with other implementations, the flexible support layer 210 may be or include one or more sublayers selected from plastics, polymeric materials, metallized plastics, metals, paper, multilayers thereof, or combinations thereof. Examples of suitable polymeric materials include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), poly(methyl methacrylate) (PMMA), cellulose triacetate (TAC), polypropylene (PP), polyethylene (PE), polycarbonate (PC), multilayers thereof, or combinations thereof.

[0029] In one or more implementations that can be combined with other implementations, the flexible support layer 210 has a thickness ranging from about 1 micrometer to about 100 micrometers, or from about 1 micrometer to about 100 micrometers, or from about 10 micrometers to about 50 micrometers, or from about 25 micrometers to about 50 micrometers.

[0030] refer to Figure 2B At operation 102, a seed layer 220 is formed above the flexible support layer 210. The seed layer 220 is formed on the front side 210f of the flexible support layer 210. The seed layer 220 has a front side 220f (also called a front surface) and a back side 220b (also called a back surface) opposite to the front side 220f. In one or more implementations, the seed layer 220 is formed on the front side 210f of the flexible support layer 210 such that the back side 220b of the seed layer 220 contacts the front side 210f of the flexible support layer 210. In other implementations, the flexible support layer 210 may have a release layer pre-fabricated on the front side 210f. In such an implementation, the seed layer 220 is formed above the release layer provided on the flexible support layer 210.

[0031] The seed layer 220 can be or includes any material suitable for releasing the SIDT stack 255 from the flexible support layer 210 during the SIDT process and subsequently providing a passivation layer for the SIDT stack 255. Subsequent deposition of the seed layer 220 onto the flexible support layer 210 and an alkali metal layer (e.g., lithium metal layer 250) to form the SIDT stack 255 advantageously provides customized control over the seed layer 220 used, which can achieve improved manufacturing efficiency and improved electrochemical performance of the formed SIDT stack 255. For example, in some implementations, the alkali metal layer can be deposited in direct contact with the seed layer 220. Therefore, the chemical properties and reactions between the seed layer 220 and the subsequently deposited alkali metal layer can be controlled so that the reactions between the seed layer 220 or between the seed layer 220 and the layers of the SIDT stack 255 do not result in an ohmic layer that increases the cell impedance at the anode-separator interface.

[0032] In one or more implementations, the seed layer 220, which is implemented to provide passivation to the alkali metal layer (e.g., the lithium metal layer 250 in the SIDT stack 255), can be configured such that the electrochemical properties between the seed layer 220 and the lithium metal layer 250 deposited thereon improve the electrochemical performance of the SIDT stack in an energy storage device. For example, the seed layer 220 can be configured not to impede ion or electron transport in the battery cell architecture, thereby maintaining the impedance of the formed anode film stack at less than about 200 ohms / cm. 2 In some implementations, the seed layer 220 maintains the impedance of the formed anolyte stack at approximately 5 ohms / cm. 2With approximately 200 ohms / cm 2 between.

[0033] In one or more implementations that can be combined with other implementations described herein, the seed layer 220 may be selected from LiF, Li2CO3, Ag, Bi, Sn, Ag+LiF, Bi+LiF, Sn+LiF, AgF, CxFy, or combinations thereof. The composition of the seed layer 220 may also be selected based on the specific battery chemistry and application to which the anode film stack to be formed is intended to be used. In one or more implementations that can be combined with other implementations, the material of the seed layer 220 may be selected and customized based on the chemistry and reaction of the alkali metal layer to be deposited on the seed layer 220, and the specific battery chemistry and application to which the anode film stack to be formed is intended to be used.

[0034] Any suitable process can be used to form the seed layer 220 on the front side of the flexible support layer 210. In some implementations, the seed layer 220 can be deposited using vapor deposition techniques, such as sputtering, reactive sputtering, evaporation, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma-assisted chemical vapor deposition (PECVD), or other similar vapor deposition processes. In one or more implementations that can be combined with other implementations, the seed layer 220 is deposited using a mixed process gas of Ar and CO2. Forming the seed layer 220 via vapor deposition techniques advantageously enables and provides control over the design of the thickness, release pressure, particles, and pinholes in the seed layer 220, thereby ensuring consistent, predictable, and high-quality lithium transfer. For example, in one or more implementations, depositing the seed layer 220 via vapor deposition in a vacuum provides control over the provided flexible support layer 210 and the formation of the seed layer 220 thereover. This control enables the mitigation and reduction of particle and pinhole defects that could otherwise be caused by the flexible support layer 210 when the seed layer 220 is deposited.

[0035] In one or more implementations, the polymer material of the flexible support layer 210 and / or seed layer 220 is selected such that the SIDT stack 255 can be debonded from the flexible support layer 210 by pressure-induced peeling. In other implementations, the seed layer 220 can be configured to be debonded by laser-induced peeling. Without being bound by theory, it is believed that a seed layer 220 configured with weak interlayer bonding facilitates subsequent separation of the seed layer 220 from the flexible support layer 210. In one or more implementations, the seed layer 220 can be configured with a bonding strength of approximately 0.3 g / cm². 2 With approximately 16 gf / cm 2 Release pressure between them.

[0036] The seed layer 220 can also be deposited under atmospheric, near-atmospheric, or vacuum conditions. In one or more implementations, the seed layer 220 can be deposited in a vacuum environment (such as a vacuum chamber) using vacuum processes. In one implementation, the seed layer 220 can be deposited at approximately 1 x 10⁻⁶ cm². -3 mbar and approximately 1x10 -6 Deposited in vacuum environments between mbar, such as below approximately 1x10 -2 mbar or below approximately 1x10 -4 mbar. In some implementations, prior to operation 102, the flexible support layer 210 can be transferred to a vacuum coating system, for example, Figure 6 The flexible substrate coating apparatus 600 is shown. The flexible substrate coating apparatus 600 can then be used to deposit a seed layer 220 in a roll-to-roll deposition system under vacuum.

[0037] In some implementations, the seed layer 220 may comprise a monolayer of material deposited on the flexible support layer 210, wherein the seed layer 220 is capable of separating from the flexible support layer 210 during SIDT and subsequently serves as a passivation layer. In other implementations, the seed layer 220 may comprise multiple sublayers of different materials deposited on the flexible support layer 210. In such implementations, certain sublayers of the seed layer 220 may be configured to separate from each other during SIDT to facilitate the release of the SIDT stack 255 from the flexible support layer 210. In such implementations, the sublayers of the seed layer 220 transferred along with the SIDT stack 255 may subsequently serve as a surface passivation layer for the SIDT stack 255.

[0038] In one or more implementations that can be combined with other implementations herein, the seed layer 220 has a thickness ranging from about 1 nm to about 5,000 nm, such as about 10 nm to about 1,000 nm, and about 100 nm to about 500 nm. In some implementations, the seed layer 220 comprises multiple sublayers, each having a thickness of about 50 nm or less. In one or more implementations, the thickness of the seed layer 220 may be adjusted based on the release pressure required to separate the SIDT stack 255 from the flexible support layer 210.

[0039] In one or more implementations that can be combined with other implementations herein, the seed layer 220 can be patterned or selectively deposited to create localized lithium deposition regions for customized battery designs. Since the seed layer 220 serves as a release layer for separating the SIDT stack 255 from the flexible support layer 210 during SIDT, it can be patterned or selectively deposited for localized interface debonding to transfer the corresponding SIDT stack 255 to the receiving substrate 260. In one or more implementations that can be combined with other implementations discussed herein, the seed layer 220 can therefore be patterned or selectively deposited on the flexible support layer 210 to transfer the lithium metal layer 250 to the receiving substrate 260.

[0040] refer to Figure 2C Optionally, at operation 103, a solid electrolyte layer 230 is formed over the seed layer 220. The solid electrolyte layer 230 has a front side 230f (also referred to as the front surface) and a back side 230b (also referred to as the back surface) opposite the front side 230f. In one or more implementations, the solid electrolyte layer 230 is deposited on the front side 220f of the seed layer 220 such that the back side 230b of the solid electrolyte layer 230 is in contact with the front side 220f of the seed layer 220. The solid electrolyte layer 230 can be formed on the front side 220f of the seed layer 220 using any suitable process. The solid electrolyte layer 230 can be deposited using a non-vacuum coating technique.

[0041] The solid electrolyte layer 230 may comprise any suitable material compatible with the target ion conduction. In some implementations, the solid electrolyte layer 230 may comprise or comprise a metal salt, such as a lithium salt. The lithium salt may be one or more of LiPF6, LiAsF6, LiCF3SO3, LiN(CF3SO3)3, LiBF6, LiClO4, or a combination thereof. The electrolyte may be in a gel or polymer matrix medium.

[0042] In one or more implementations, the solid electrolyte layer 230 may be or include a material selected from: fluorocarbons (PTFE, PVDF), LiF, Li2CO3, MgO, AlOx, AlHO2, RENiO3 (RE = rare earth), BN, BaTiO3, Li4Ti5O12, ZrO2, TiO2, silicon-doped lithium tantalum phosphate, such as Li(1+x)Ta2P(1-x)SixO8, Li1.5Ta2P0.5Si0.5O8, lithium tantalum phosphate, such as LiTa2PO8 (LTPO), Li2Ta2SiO8 (LTSO), Li0.34La0.56TiO3, lithium aluminum titanium phosphate, such as Li1.3Al0.3Ti1.7(PO4)3 (LATP), lithium aluminum germanium phosphate, such as Li1.3Al0.3Ge1.7(PO4)3 (LAGP), garnet Li7La3Zr2O12 (LLZO), or combinations thereof.

[0043] In one or more implementations, the solid electrolyte layer 230 can be formed using a non-vacuum coating technique. Suitable coating techniques include, but are not limited to, slot die coating, blade coating, three-dimensional (3D) printing, or combinations thereof. In one or more alternative implementations, the solid electrolyte layer 230 can be formed using a vacuum coating technique. In some implementations, the solid electrolyte layer 230 can be formed using, for example... Figure 6 The flexible substrate coating equipment 600 shown performs deposition.

[0044] refer to Figure 2D Optionally at operation 104, one or more interface layers 240 are formed over the solid electrolyte layer 230. The interface layer 240 is disposed between the seed layer 220 and the lithium metal layer 250. The interface layer 240 may include at least one of an interface dielectric material, an electroplating and release reinforcement layer, and a lithiophilic layer. The interface layer 240 can be deposited under vacuum. The interface layer 240 can be deposited under vacuum in a roll-to-roll deposition system; for example, the solid electrolyte layer 230 may use... Figure 6 The flexible substrate coating apparatus 600 shown is used for deposition. The interface layer 240 can be deposited by vapor deposition techniques, such as chemical vapor deposition (CVD), atomic layer deposition (ALD), physical vapor deposition (PVD), such as thermal evaporation or sputtering.

[0045] The interface dielectric layer can be selected from AlOx, AlOOH, LiF, BaTiO3, ZrO2, TiO2, Li4Ti5O12, LiAlO2, AlF3, BiF3, AgFx, rare earth (RE) nickelates (RENiO3), or combinations thereof. RE can be trivalent rare earth elements. RE can be lanthanides. RE can be selected from La, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Y, Lu, or combinations thereof. RE can be selected from Sm, Nd, and Eu. RE nickelates can be doped with ions. Suitable ions for doping include lithium ions, sodium ions, magnesium ions, potassium ions, hydrogen ions, and aluminum ions. In one example, the RE nickelate is lithium-ion-doped SmNiO3. The electroplating and stripping reinforcement layer can be or includes an alloy of metals or chalcogenides. The electroplating and stripping reinforcement layer can be or includes Ag, Bi, Sn, Si, Cu, metallic alloys of Ag, Bi, Sn, Si, Cu, or chalcogenides, or combinations thereof. The lithiophilic layer may be or include at least one of the following: a metal or alloy thereof including Al, Au, Ag, Bi, Pt, Zn, Si, Sn, Mg, In, Ga or Cu, or a metal oxide including Li4Ti5O12, RENiO3, AlOx, CuO, ZnO, CoO or MnO.

[0046] In one or more implementations that can be combined with other implementations, one or more interface layers 240 include a dielectric layer. The dielectric layer may be lithium fluoride, aluminum oxide, aluminum hydroxide, boron nitride, carbon nitride, titanium oxide, lithium titanium oxide, zirconium oxide, tantalum oxide, barium titanate, lithium zirconium oxide, molybdenum oxide, silicon oxide, lithium silicon oxide, or combinations thereof.

[0047] In one or more implementations that can be combined with other implementations, one or more interface layers 240 include electroplating and release reinforcement layers. The electroplating and release reinforcement layers may comprise a metal layer. The metal layer may be or include silver, bismuth, tin, copper, aluminum, silicon, or combinations thereof. The electroplating and release reinforcement layers may include a metal layer. The metal layer may be or include silver, bismuth, tin, copper, aluminum, silicon, indium, gallium, or combinations thereof. The electroplating and release reinforcement layers may be selected from Ag, Bi, Sn, Si, Cu, Al, metal alloys of Ag, Bi, Sn, and Si, or chalcogenides, or combinations thereof.

[0048] In one or more implementations that can be combined with other implementations, one or more interface layers 240 include a lithiophilic layer. A lithiophilic layer enables the lateral growth of a subsequently deposited lithium metal layer 250. The lithiophilic layer can be or includes a metal or a metal oxide. The lithiophilic layer can be or includes at least one of the following: a metal or alloy thereof including Al, Au, Ag, Bi, Pt, Zn, Si, Sn, Mg, In, Ga, or Cu; or a metal oxide including Li4Ti5O12, RENiO3, AlOx, CuO, ZnO, CoO, or MnO. The lithiophilic layer can be deposited by at least one process selected from the group consisting of immersion, spin coating, dip coating, spray coating, blade coating, solution casting, drop coating, PVD, and CVD.

[0049] In one or more implementations that can be combined with other implementations, a passivation layer may optionally be included in the SIDT stack 255, such as by forming it prior to the deposition of the lithium metal layer 250. Forming a surface passivation in the SIDT stack 255 prior to the deposition of the lithium metal layer 250 provides immediate protection for the lithium metal layer 250 (e.g., by the surface passivation layer) after the SIDT stack 255 is laminated to the receiving substrate 260. As discussed above, the seed layer 220 may be configured to act as a release layer for separating the SIDT stack 255 from the flexible support layer 210 during the lamination transfer of the lithium metal layer 250. At least a portion of the seed layer 220 is configured to be transferred together with the SIDT stack 255 onto the receiving substrate 260 to provide passivation for the subsequently formed anode film stack 265. Therefore, the seed layer 220 described herein can improve manufacturing efficiency by avoiding the need for an additional step of forming a passivation layer before depositing the lithium metal layer 250, while still providing the same benefits and advantages by providing passivation for the anode film stack 265 to be formed.

[0050] refer to Figure 2E In operation 105, a lithium metal layer (e.g., lithium metal layer 250) is formed above the front side 220f of the seed layer 220. The lithium metal layer 250 includes a front side 230f (also called a front surface) and a back side 230b (also called a back surface) opposite the front side 230f. In some implementations, if any of the solid electrolyte layer 230 and one or more interface layers 240 are present, the lithium metal layer 250 can be formed directly on the underlying layer, for example, any of the solid electrolyte layer 230 and one or more interface layers 240. In some implementations, if the solid electrolyte layer 230 and one or more interface layers 240 are not present, the lithium metal layer 250 can be formed directly on the front side 220f of the seed layer 220.

[0051] The lithium metal layer 250 may be or includes lithium. The lithium metal layer 250 can be deposited under vacuum. The lithium metal layer 250 can be deposited under vacuum in a roll-to-roll deposition system (e.g., Figure 6 Deposition is performed in the flexible substrate coating apparatus 600 shown. In some implementations, operations 102 to 105 can be used. Figure 6 The same flexible substrate coating apparatus 600 shown is used to perform the process, thereby enabling the seed layer 220 and the SIDT stack 255 formed thereon to be deposited on the flexible support layer 210 without breaking the vacuum. The lithium metal layer 250 can be deposited via a physical vapor deposition process, such as an evaporation process or a sputtering process. The evaporation process can be an electron beam evaporation process or a thermal evaporation process.

[0052] refer to Figure 2E The lithium metal layer 250 completes the flexible support layer stack 200. The seed layer 220, the solid electrolyte layer 230 (if present), one or more interface layers 240 (if present), and the lithium metal layer 250 form the SIDT stack 255. In some implementations, the SIDT stack 255 may include only a portion of the seed layer 220.

[0053] The formation of the SIDT stack 255 described herein allows for the final deposition of a lithium metal layer 250 onto the flexible support layer stack 200. This final deposition of the lithium layer enables the formation of the SIDT stack 255 without damaging the lithium layer, which typically has a lower melting point compared to other materials formed in the energy storage device. Conventional methods for forming energy storage devices include depositing molten lithium directly onto a current collector during lithium metal anode formation or depositing molten lithium directly onto an anode material in a pre-lithiation implementation. These methods further include maintaining the underlying substrate during the formation of the lithium metal layer 250 to prevent damage to the lithium. In contrast, the flexible support layer stack 200 and the methods described herein enable the final formation of the lithium metal layer 250 during operation 106 before transferring the SIDT stack 255 to the receiving substrate 260.

[0054] In some implementations that can be combined with other implementations, a passivation layer may optionally be included in the SIDT stack 255. In some implementations, the passivation layer comprises a carbonate of an alkali metal in an alkali metal layer (e.g., lithium metal layer 250). In some implementations that can be combined with other implementations, the alkali metal layer is a lithium metal layer, such as in lithium metal layer 250, and the passivation layer comprises lithium carbonate. The passivation layer can be formed by exposing lithium metal layer 250 to carbon dioxide. In some implementations, lithium metal layer 250 is exposed to carbon dioxide in the presence of heat. It is believed, without being bound by theory, that carbon dioxide reacts with lithium metal to form a thin layer of lithium carbonate on the exposed surface of lithium metal layer 250. In some implementations, the lithium carbonate passivation layer (e.g., lithium carbonate passivation layer) may have a thickness ranging from about 50 nm to about 100 nm. The lithium carbonate passivation layer can be used as a protective layer for lithium metal layer 250. For example, a lithium carbonate metal passivation layer can protect the lithium metal layer 250 from oxidation and damage during storage and transportation.

[0055] After and before operation 105, the flexible support layer stack 200 containing the SIDT stack 255 can be removed from a vacuum coating system (e.g., Figure 6 The flexible substrate coating apparatus 600 shown is transferred to a lamination transfer apparatus (e.g., Figure 7 The lamination transfer system 700 shown. The lamination transfer process may include applying a receiving substrate 260 to the front side 250f of the lithium metal layer 250 and removing the SIDT stack 255 from the flexible support layer 210 to form the anode film stack 265. As discussed above, removing the SIDT stack 255 from the flexible support layer 210 may include separating the seed layer 220 from the flexible support layer 210, or separating certain sublayers of the seed layer 220.

[0056] refer to Figure 2GAt operation 106, the SIDT stack 255 is transferred from the flexible support layer 210 to the receiving substrate 260 to form the anode film stack 265. As shown, operation 106 may include lamination transfer onto the current collector to form the anode film stack 265. In some implementations, where pre-lithiation is involved, the anode material may have already been formed over the receiving substrate 260, and the lithium metal layer 250 is transferred over the anode material formed over the receiving substrate 260. The receiving substrate 260 may be or include a flexible film, such as a CPP film (i.e., cast polypropylene film), an OPP film (i.e., oriented polypropylene film), or a PET film (i.e., polyethylene terephthalate film). Alternatively, the receiving substrate 260 may be pre-coated paper, polypropylene (PP) film, PEN film, polylactic acid (PLA) film, or PVC film. The receiving substrate 260 may be or include one or more current collectors, which may include aluminum (Al), copper (Cu), zinc (Zn), nickel (Ni), cobalt (Co), manganese (Mn), chromium (Cr), stainless steel, cladding materials, alloys thereof, and combinations thereof. In various implementations, the receiving substrate 260 may be or include copper or copper foil.

[0057] In one or more implementations that can be combined with other implementations, during operation 106, such as Figure 2F As shown, the seed layer 220 is transferred together with or partially transferred with the SIDT stack 255. As discussed above, once transferred, the seed layer 220 also serves as a surface passivation layer for the anolyte stack 265. The seed layer 220 can be used as a protective layer for the lithium metal layer 250. For example, the seed layer 220 can protect the lithium metal layer 250 from oxidation and damage during storage and transportation.

[0058] refer to Figure 2G At operation 107, the anode film stack 265 may optionally be combined with the separator 290, the cathode stack 285, or both the separator 290 and the cathode stack 285 to form an energy storage device 295. In some embodiments, although in Figure 2G The diagram shows a planar structure. The energy storage device 295 can also be formed into a cylinder by stacking layers of winding; in addition, other battery configurations (e.g., prismatic cells, button cells, or stacked electrode cells) can also be formed.

[0059] As a non-limiting example, separator 290 may include a microporous polymeric separator comprising a polyolefin. The polyolefin may be a homopolymer (derived from a single monomeric component) or a hybrid (derived from more than one monomeric component), and may be linear or branched. If the hybrid is derived from two monomeric components, the polyolefin may exhibit any copolymer chain arrangement, including those of block copolymers or random copolymers. Similarly, if the polyolefin is a hybrid derived from more than two monomeric components, it may also be a block copolymer or a random copolymer. In some implementations, the polyolefin may be polyethylene (PE), polypropylene (PP), or a mixture of PE and PP, or a multilayer structured porous membrane of PE and / or PP. Commercially available polyolefin porous membranes include CELGARD® 2500 (single-layer polypropylene separator) and CELGARD® 2320 (triple-layer polypropylene / polyethylene / polypropylene separator), both supplied by Celgard LLC.

[0060] In one or more implementations that can be combined with other implementations, the cathode stack 285 includes a cathode current collector 280 and a cathode material 270. The cathode current collector 280 can be or includes any of the aforementioned flexible thin films, as well as aluminum (Al), copper (Cu), zinc (Zn), nickel (Ni), cobalt (Co), tin (Sn), silicon (Si), manganese (Mn), magnesium (Mg), their alloys, and combinations thereof. In some implementations, the cathode current collector 280 can be or contains aluminum.

[0061] Cathode material 270 may be or include any suitable cathode material. Cathode material 270 or the cathode may be or contain any material compatible with the anode, and may include intercalating compounds, insertion compounds, or electrochemically active polymers. Suitable intercalating materials include, for example, sulfur, lithium-containing metal oxides, MoS2, FeS2, MnO2, TiS2, NbSe3, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, and V6O. 13 And V2O5. Suitable polymers include, for example, polyacetylene, polypyrrole, polyaniline, and polythiophene. In some implementations, the cathode material 270 comprises a polymer binder as described herein. The cathode material 270 or the cathode may be or comprise a layered oxide, such as lithium cobalt oxide, olivine, such as lithium iron phosphate, or spinel, such as lithium manganese oxide. Examples of lithium oxides may be layered, such as lithium cobalt oxide (LiCoO2), or mixed metal oxides, such as LiNi. x Co 1-2x MnO2, LiNiMnCoO2 (“NMC”), LiNi 0.5 Mn 1.5 O4, Li(Ni) 0.8 Co 0.15 Al0.05 O2, LiMn2O4, and doped lithium-rich layered materials, where x is a zero or non-zero number. Examples of phosphates can be or include fir olivine (LiFePO4) and its variants (e.g., LiFe... (1-x) Mg x PO4), LiMoPO4, LiCoPO4, LiNiPO4, Li3V2(PO4)3, LiVOPO4, LiMP2O7 or LiFe 1.5 P₂O₇, where x is a zero or non-zero number. Examples of fluorophosphates can be or include LiVPO₄F, LiAlPO₄F, and Li₅V(PO₄). 2G2 Li5Cr(PO4) 2G2 Li₂CoPO₄F or Li₂NiPO₄F. Examples of silicates can be or include Li₂. 2G eSiO4, Li2MnSiO4, or Li2VOSiO4. Examples of non-lithium compounds may include Na5V2(PO4). 2G3 .

[0062] Figure 3 A flowchart is shown of a method 300 for manufacturing an energy storage device according to one or more implementations of the present disclosure. Figure 4A Figure 4F shows the results according to Figure 3 Method 300 provides a view of the various stages of manufacturing an energy storage device. Although... Figures 4A to 4E It is about the description of method 300, but it should be understood that... Figures 4A to 4E The structure disclosed herein is not limited to method 300, but can exist independently as a structure independent of method 300. Similarly, although method 300 is about... Figures 4A to 4E As described, but it should be understood that Method 300 is not limited to Figures 4A to 4E The structure is not publicly available, but can be independent of... Figures 4A to 4E It exists based on the publicly disclosed structure.

[0063] It should be understood that Figures 4A to 4E Only a partial schematic diagram of the energy storage device is shown, and the energy storage device may contain any number of additional layers and / or additional materials common to energy storage devices; for the sake of brevity, these additional layers and / or additional materials are not illustrated. It should also be noted that, although... Figure 3 The method 300 shown herein is described in sequence, but other process sequences including one or more operations that have been omitted and / or added and / or rearranged in another desired order fall within the scope of the implementation of this disclosure provided herein.

[0064] refer to Figure 4AAt operation 301, a flexible support layer stack 400 is provided. The flexible support layer stack 400 includes at least a flexible support layer 410, a seed layer 420, and a lithium metal layer 430. The flexible support layer 410, seed layer 420, and lithium metal layer 430 correspond to the flexible support layer 210, seed layer 220, and lithium metal layer 250 as described herein with respect to method 100. The seed layer 420 may be disposed above the flexible support layer 410 as described in operation 102. The lithium metal layer 430 may be disposed above the seed layer 420 as described in operation 105.

[0065] After operation 301, the flexible support layer stack 400 having the lithium metal layer 430 or SIDT stack 435 formed thereon can be removed from a vacuum coating system (e.g., Figure 6 The flexible substrate coating apparatus 600 shown is transferred to a lamination transfer apparatus (e.g., Figure 7 The lamination transfer system 700 shown. The lamination transfer process may include applying a receiving substrate to the front side 430f of the lithium metal layer 430 and removing the flexible support layer 410 from the SIDT stack 435 to form an anode film stack 465.

[0066] In one or more implementations that can be combined with other implementations, optionally, at operation 302, the flexible support layer stack 400 having the lithium metal layer 430 formed thereon is exposed to a preheating process prior to the lamination process at operation 303. For example... Figure 4B As shown, the preheating process may include exposing the lithium metal layer 430 to thermal energy, such as thermal energy 438 provided by an IR lamp source. In some implementations, when the lithium metal layer 430 is a thicker layer, preheating the lithium metal layer 430 may facilitate or accelerate the lamination process. In some implementations, the preheating temperature may be in the range of about 30 degrees Celsius to about 200 degrees Celsius. In some implementations, the preheating time may be between about 1 second and about 90 seconds. However, the preheating time may vary based on the speed at which the receiving substrate 440 and the flexible support layer 410 are conveyed through the lamination transfer system 700. For example, in some implementations, the receiving substrate 440 and the flexible support layer 410 may be conveyed through the lamination transfer system 700 at a speed of about 0.2 m / min to about 25 m / min (such as between about 0.5 m / min and about 10 m / min).

[0067] refer to Figure 4CAt operation 303, the lithium metal layer 430 is laminated onto the receiving substrate 440. The receiving substrate 440 may include one or more layers. In some implementations, for example, for a lithium metal anode device, the receiving substrate 440 may include a current collector. In some implementations, for example, for a pre-lithiation process, the receiving substrate 440 may include an anode material formed above the current collector. In yet other implementations, the receiving substrate 440 may be or include a separator and / or a cathode stack, for example, as... Figure 2G The partition 290 and cathode stack 285 are shown.

[0068] In one or more implementations that can be combined with other implementations, the receiving substrate 440 includes a roll-to-roll substrate; for example, the current collector may be a roll-to-roll substrate. Any suitable current collector can be used. The current collector may include, but is not limited to, aluminum (Al), copper (Cu), zinc (Zn), nickel (Ni), cobalt (Co), manganese (Mn), chromium (Cr), stainless steel, cladding materials, metallized plastics, paper, stainless steel, metal mesh, metal foil, or combinations thereof. Any suitable anode material can be used. The anode material may include, but is not limited to, graphite, silicon, graphite silica, graphite silica, silicon, or combinations thereof.

[0069] During the lamination process of operation 303, the lithium metal layer 430 comes into contact with the receiving substrate 440. For example, the front side 430f of the lithium metal layer 430 contacts the surface of the receiving substrate 440, such as... Figure 4C As shown. In some implementations, where the receiving substrate 440 only includes a current collector, the front side 430f of the lithium metal layer 430 contacts the surface of the current collector. In some implementations, where the receiving substrate 440 includes an anode material, the front side 430f of the lithium metal layer 430 contacts the surface of the anode material to pre-lithiate the anode material.

[0070] In some implementations, operations 302 and 303 can occur simultaneously, sequentially, or partially overlap.

[0071] refer to Figure 4DOptionally, at operation 304, pressure is applied to one or more of the receiving substrate 440 and the flexible support layer stack 200 having the lithium metal layer 430 formed thereon to laminate the receiving substrate 440 to the lithium metal layer 430. In some implementations, where method 300 is performed in a roll-to-roll tool, the roll tension is sufficient to laminate the lithium metal layer 430 to the receiving substrate 440, and no additional pressure is required. In some implementations, where additional pressure is used to laminate the lithium metal layer 430 to the receiving substrate 440, the lamination process includes pressing the lithium metal layer 430 to the receiving substrate 440 with a pressure sufficient to attach the lithium metal layer 430 to the receiving substrate 440 without damaging the lithium metal layer 430. In other words, the pressure prevents the lithium metal layer 430 from being mechanically damaged or degraded, such as by cracking or crushing.

[0072] Pressure can be applied using any suitable technique. In one or more implementations, pressure is applied via a calendering process. The calendering process may include the use of a pair of calendering rolls 442a, 442b, such as... Figure 4D As shown. For example, pressure can be applied to the back side 410b of the flexible support layer 410 and the back side 440b of the receiving substrate 440. In one or more other implementations, the pressure is applied by a vacuum source. In one or more other implementations, the pressure is external pressure. In one or more implementations, the calendering rolls 442a, 442b can also be heated.

[0073] In some implementations, operations 303 and 304 can occur simultaneously, sequentially, or partially overlap.

[0074] refer to Figure 4E At operation 305, the flexible support layer 410 separates from the SIDT stack 435 to form an anode film stack 465 on the receiving substrate 440. After removing the flexible support layer 410, a lithium metal layer 430 is disposed between at least a portion of the seed layer 420 at one end of the anode film stack 465 and the receiving substrate 440 at the opposite end of the anode film stack 465. The seed layer 420 or a portion of the seed layer 420 disposed at the end of the anode film stack 465 may then be used as a surface passivation layer for the lithium metal layer 430 disposed between the seed layer 420 and the receiving substrate 440. The surface passivation layer may include the seed layer 420 or certain sublayers of the seed layer 420.

[0075] At operation 306, the anolyte stack 465 may be integrated with the separator, the cathode stack, or both, as described above in operation 107. Figure 2G As shown in the figure, it forms an energy storage device.

[0076] Figure 5A schematic diagram of a transfer system 500 is shown, which is used to transfer materials in a roll-to-roll tool according to... Figure 3 The method of manufacturing energy storage devices, and for use in, for example Figure 7 In the roll-to-roll process of the lamination transfer system 700 shown, in one or more implementations that can be combined with other implementations, the lamination transfer processes of operations 303 and 305 may include transferring lithium metal layers 530, 532 from separate SIDT stacks to opposite sides of the flexible receiving substrate 540. The SIDT stacks comprising lithium metal layers 530, 532 and seed layers 520, 522 respectively disposed on flexible support layers 510, 512 may each be provided as discussed in operation 301.

[0077] The transfer system 500 includes a first flexible carrier supply hub 515 and a second flexible carrier supply hub 525. A supply roller 511 of the flexible support layer 510 is positioned on the first flexible carrier supply hub 515. The supply roller 511 may include a lithium metal layer 530 and a seed layer 520 formed on the flexible support layer 510. A supply roller 521 of the flexible support layer 512 is positioned on the second flexible carrier supply hub 525. The supply roller 511 may include a lithium metal layer 532 and a seed layer 522 formed on the flexible support layer 512.

[0078] The transfer system 500 also includes a flexible receiving substrate supply hub 535. A supply roller 531 of the flexible receiving substrate 540 is positioned on the flexible receiving substrate supply hub 535. Supply rollers 511 and 521 are conveyed via a rolling unit 550 such that the lithium metal layer 530 on the flexible support layer 510 faces the upper surface 540U of the flexible receiving substrate 540, and the lithium metal layer 532 on the flexible support layer 512 faces the lower surface 540L of the flexible receiving substrate 540.

[0079] The transfer system 500 also includes a calendering unit 550. The calendering unit 550 includes one or more calendering rolls, such as a first calendering roll 551 and a second calendering roll 582. Flexible support layers 510, 512, and a flexible receiving substrate 540 are arranged to be conveyed along a path extending therebetween through the calendering unit 550. As the flexible support layers 510, 512, and the flexible substrate stack 1540 are conveyed between the first calendering roll 551 and the second calendering roll 582, the flexible receiving substrate 540 is positioned between the flexible support layers 510 and 512. The first calendering roll 551 and the second calendering roll 582 apply substantial pressure to the flexible support layers 510, 512 and the flexible receiving substrate 540, causing the SIDT stack on each flexible support layer 510, 512 to transfer to the flexible receiving substrate 540. In some implementations, the first calendering roll 551 and the second calendering roll 582 may also be heated to facilitate the lamination and transfer of lithium metal layers 530, 532. Subsequently, tension is applied to the flexible support layers 510, 512 by the first calendering roll 582 and the second calendering roll 584 to peel each flexible support layer 510, 512 from the flexible receiving substrate 540 and form a film stack 560.

[0080] The transfer system 500 includes a first flexible carrier pickup hub 516 and a second flexible carrier pickup hub 526. The pickup roller 512 of the flexible support layer 510 is positioned on the first flexible carrier pickup hub 516. The pickup roller 522 of the second flexible carrier 412 is positioned on the second flexible carrier pickup hub 526. When the flexible support layer 510 is wound onto the first flexible carrier pickup hub 516, the lithium metal layer 530 and the seed crystal layer 520 are no longer on the flexible support layer 510 because the lithium metal layer 530 and the seed crystal layer 520 previously on the first flexible carrier 110 have been transferred to the flexible receiving substrate 540 via rolling rollers 551 and 582. Similarly, when the flexible support layer 512 is wound onto the second flexible carrier pickup hub 526, the lithium metal layer 532 and the seed crystal layer 522 are no longer on the flexible support layer 512, because the lithium metal layer 532 and the seed crystal layer 522 previously on the flexible support layer 512 are also transferred to the flexible receiving substrate 540 via the rolling rollers 551, 582. In some implementations, the rollers 582, 584 may alternatively be configured as pickup hubs with corresponding pickup rollers to recapture or recover the flexible support layers 510, 512.

[0081] The transfer system 500 includes a flexible substrate stack pickup hub 570. A pickup roller 562 of a flexible receiving substrate 540 is positioned on the flexible substrate stack pickup hub 570. The flexible receiving substrate 540 includes a film stack 560, wherein a lithium metal layer 530 is disposed between a seed layer 520 and an upper surface 540U of the flexible receiving substrate 540, and a lithium metal layer 532 is disposed between a seed layer 522 and a lower surface 540L of the flexible receiving substrate 540. The seed layers 520 and 522 in the film stack 560 can serve as surface passivation layers for the lithium metal layers 530 and 532. The film stack 560 can then be transferred to the flexible substrate pickup roller 570.

[0082] The transfer system 500 also includes a plurality of rollers 581-584. In some implementations, each roller 581-584 may be a passive roller. During each movement of the flexible support layers 510, 512 and the flexible receiving substrate 540 through different portions of the transfer system 500, the rollers 581-584 may help apply appropriate tension to the flexible support layers 510, 512 and the flexible receiving substrate 540 and help change the orientation of the flexible support layers 510, 512 and the flexible receiving substrate 540. Some of the rollers 581-584 may also help move the flexible support layers 510, 512 closer to or further away from the flexible receiving substrate 540. For example, the first roller 581 may help bring the flexible support layers 510, 512 into contact with the flexible receiving substrate 540 before the flexible support layers 510, 512 and the flexible receiving substrate 540 are conveyed through the rolling unit 550. Furthermore, the second calendering roll 582 and the third calendering roll 583 provide positions where tension can be applied to the flexible support layers 510, 512 to peel the flexible support layers 510, 512 from the flexible receiving substrate 540. In some implementations, one or more of the rolls 581-584 may alternatively be rods, such as metal rods, which can apply tension to the carrier or flexible substrate during movement of the carrier or flexible substrate.

[0083] The transfer system 500 may also include a housing 517 disposed around the internal space 508. The housing 517 may be used to maintain a separate environment within the internal space 508 relative to the environment surrounding the transfer system 500. For example, the internal space 508 may have different gas concentrations and different temperatures and / or pressures relative to the environment surrounding the transfer system 500.

[0084] Figure 6 A schematic diagram of a flexible substrate coating apparatus 600 for forming at least a portion of an anolyte film stack, described according to one or more implementations of this disclosure, is shown. The flexible substrate coating apparatus 600 may be a roll-to-roll coating system. The flexible substrate coating apparatus 600 may be used to perform portions of the methods 100 and 300 described herein that can be performed using vacuum deposition.

[0085] The flexible substrate coating apparatus 600 can be a SMARTWEB® device manufactured by Applied Materials, suitable for manufacturing lithium anode devices according to the implementations described herein. According to some implementations, the flexible substrate coating apparatus 600 can be used to manufacture lithium anodes or pre-lithiated anodes, and particularly for portions of SIDT stacks 255 containing lithium films. The flexible substrate coating apparatus 600 is configured as a roll-to-roll system including a deployment module 602, a processing module 604, and a winding module 606. In one or more implementations, the processing module 604 includes a plurality of processing modules or chambers 610, 620, 630, and 640 arranged in sequence, each processing module or chamber configured to perform a processing operation on a continuous sheet of material 650 or a roll of material (e.g., a flexible support layer 210 or a flexible support layer stack 200). In one or more implementations, such as Figure 6 As depicted, processing chambers 610-640 are arranged radially around the coating drum 655. Arrangements other than radial are contemplated. For example, in another implementation, the processing chambers may be linearly positioned.

[0086] In one implementation, processing chambers 610-640 are independent modular processing chambers, each structurally separate from the others. Therefore, each independent modular processing chamber can be arranged, rearranged, replaced, or maintained independently without affecting others. Although four processing chambers 610-640 are illustrated, it should be understood that the flexible substrate coating apparatus 600 may include any number of processing chambers.

[0087] Processing chambers 610-640 may include any suitable structure, configuration, arrangement, and / or components that enable the flexible substrate coating apparatus 600 to deposit portions of the SIDT stack according to an implementation of this disclosure. For example, but not limited to, the processing chambers may include suitable deposition systems, including a coating source, power supply, separate pressure control, deposition control system, and temperature control. According to typical implementations, the chambers have separate gas supplies. The chambers are typically separated from each other to provide good gas separation. The flexible substrate coating apparatus 600 according to the implementations described herein is not limited in the number of deposition chambers. For example, but not limited to, the flexible substrate coating apparatus 600 may include 3, 6, or 12 processing chambers.

[0088] Processing chambers 610-640 typically include one or more deposition units 612, 622, 632, and 642. Generally, the one or more deposition units as described herein can be selected from the group consisting of CVD sources, ALD sources, PECVD sources, and PVD sources. One or more deposition units may include evaporation sources, sputtering sources, such as magnetron sputtering sources, DC sputtering sources, AC sputtering sources, pulsed sputtering sources, radio frequency (RF) sputtering sources, or intermediate frequency (MF) sputtering sources. One or more deposition units may include evaporation sources. In one implementation, the evaporation source is a thermal evaporation source or an electron beam evaporation source. In one implementation, the evaporation source is a lithium (Li) source. Furthermore, the evaporation source may also be an alloy of two or more metals. The material to be deposited (e.g., lithium) can be provided in a crucible. Lithium can be evaporated, for example, by thermal evaporation or electron beam evaporation techniques.

[0089] In some implementations, one or more of the chambers may be configured to perform deposition by other methods, such as, but not limited to, chemical vapor deposition, atomic layer deposition, or pulsed laser deposition. In some implementations, one or more of the chambers may be configured to perform plasma processing techniques, such as plasma oxidation or plasma nitriding processes.

[0090] In one or more implementations, processing chambers 610-640 are configured to process both sides of the continuous material sheet 650. Although the flexible substrate coating apparatus 600 is configured to process the horizontally oriented continuous material sheet 650, the flexible substrate coating apparatus 600 can be configured to process substrates positioned in different orientations; for example, the continuous material sheet 650 can be vertically oriented. In one or more implementations, the continuous material sheet 650 is a flexible support layer, such as the flexible support layer stack 200 described herein. In one or more implementations, the continuous material sheet 650 includes a PET substrate and an optional release layer.

[0091] In one or more implementations, the flexible substrate coating apparatus 600 includes a transfer mechanism 652. The transfer mechanism 652 may comprise any transfer mechanism capable of moving a continuous sheet of material 650 through the processing areas of processing chambers 610-640. The transfer mechanism 652 may include a common transport architecture. The common transport architecture may include a reel-to-reel system having a common take-up reel 654 positioned in the winding module 606, a coating drum 655 positioned in the processing module 604, and a feed reel 656 positioned in the unfolding module 602. The take-up reel 654, coating drum 655, and feed reel 656 can be individually heated. The take-up reel 654, coating drum 655, and feed reel 656 can be individually heated using an internal heat source or an external heat source located within each reel. The common transport architecture may also include one or more auxiliary transfer reels 653a, 653b positioned between the take-up reel 654, the coating drum 655, and the feed reel 656. While the flexible substrate coating apparatus 600 is depicted as having a single processing area, in one or more implementations, it may be advantageous to have separate or discrete processing areas for each individual processing chamber 610-640. For implementations with discrete processing areas, modules, or chambers, the common transport architecture may be a reel-to-reel system, wherein each chamber or processing area has a separate take-up reel and a feed reel, and one or more optional intermediate transfer reels positioned between the take-up reel and the feed reel.

[0092] The flexible substrate coating apparatus 600 may include a feed reel 656 and a take-up reel 654 for moving a continuous material sheet 650 through different processing chambers 610-640. In one or more implementations that can be combined with other implementations, each processing chamber may be configured to deposit a portion of an SIDT stack 255. In one implementation, the first processing chamber 610 and the second processing chamber 620 are each configured to deposit one or more of a seed layer 220, a protective layer, and / or an SEI layer. The third processing chamber 630 and the fourth processing chamber 640 are configured to deposit a portion of an alkali metal-containing film, such as a lithium metal layer 250.

[0093] In one implementation, processing chambers 630 and 640 are configured to deposit a lithium metal thin film on a continuous material sheet 650. Any suitable lithium deposition process can be used to deposit the lithium metal thin film. The deposition of the lithium metal thin film can be achieved through PVD processes, such as evaporation. The chambers for depositing the lithium metal thin film can include PVD systems, such as electron beam evaporators, thermal evaporators, or lamination systems.

[0094] In operation, a continuous material sheet 650 is unwound from a feed reel 656, as indicated by arrow 608 in the substrate movement direction. The continuous material sheet 650 may be guided via one or more auxiliary transfer reels 653a, 653b. Alternatively, the continuous material sheet 650 may be guided by one or more substrate guiding control units (not shown), which control the proper operation of the flexible substrate, for example, by fine-tuning the orientation of the flexible substrate.

[0095] After being unwound from the feed reel 656 and running on the auxiliary transfer reel 653a, the continuous material sheet 650 then moves through deposition areas located at the coating drum 655 and corresponding to the positions of deposition units 612, 622, 632, and 642. During operation, the coating drum 655 rotates about axis 651, causing the flexible substrate to move in the direction of arrow 608.

[0096] Figure 7 A schematic side view of a lamination transfer system 700 according to one or more implementations of the present disclosure is shown. The lamination transfer system 700 includes means for transferring a SIDT stack (e.g., SIDT stack 255) including lithium metal layers on a flexible support layer 710 (e.g., flexible support layer stack 200) and a second flexible support layer 720 (e.g., flexible support layer stack 200) to each side of a flexible receiving substrate 730 (e.g., receiving substrate 260), such that the receiving substrate 260 having the lithium metal layer 250 can be used as an electrode (e.g., an anode) or a pre-lithiated electrode in a lithium-ion battery. The lamination transfer system 700 may include a preheating unit (not shown) for preheating the SIDT stack 255 on the flexible support layers 710, 720 prior to transfer to the flexible receiving substrate 730. The lamination transfer system 700 may also include a rolling unit 740 for transferring the SIDT stack 255 on the flexible support layers 710, 720 to the flexible receiving substrate 730.

[0097] The lamination transfer system 700 includes a first flexible support layer supply hub 715. A supply roller 711 of the first flexible support layer 710 is positioned on the first flexible support layer supply hub 715. In some implementations, the first flexible support layer 710 may be formed of a polymeric material, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), metallized plastic, or combinations thereof. It includes a lithium metal layer (…). Figure 7The SIDT stack (not shown) is positioned on the lower side 710L of the first flexible support layer 710, such that when the first flexible support layer 710 and the flexible receiving substrate 730 are transferred through the rolling unit 740, the lithium metal layer faces the upper surface 730U of the flexible receiving substrate 730. The upper surface 730U of the flexible receiving substrate 730 is on the opposite side to the lower surface 730L of the flexible receiving substrate 730. The upper surface 730U is also referred to as the first surface or first side of the flexible receiving substrate 730, and the lower surface is also referred to as the second surface or second side of the flexible receiving substrate 730.

[0098] The lamination transfer system 700 includes a second flexible support layer supply hub 725. A supply roller 721 of the second flexible support layer 720 is positioned on the second flexible support layer supply hub 725. In some implementations, the second flexible support layer 720 may be formed of the same material as the first flexible support layer 710 (e.g., PET). It includes a lithium metal layer (…). Figure 7 An SIDT stack (e.g., any SIDT stack 255) not shown in the figure is positioned on the upper side 720U of the second flexible support layer 720 such that when the second flexible support layer 720 and the flexible receiving substrate 730 are transferred through the rolling unit 740, the lithium metal layer faces the lower surface 730L of the flexible receiving substrate 730.

[0099] The lamination transfer system 700 includes a flexible substrate supply hub 735. A supply roller 731 of a flexible receiving substrate 730 is positioned on the flexible substrate supply hub 735. In some implementations, the flexible receiving substrate 730 may be formed of one or more of copper, graphite, silicon, graphite silicon, graphite silica, silicon, metallized plastic, or other materials.

[0100] The lamination transfer system 700 also includes a calendering unit 740. The calendering unit 740 includes a first calendering roll 741 and a second calendering roll 742. A first flexible support layer 710, a second flexible support layer 720, and a flexible receiving substrate 730 are arranged to be conveyed along a path extending between the first calendering roll 741 and the second calendering roll 742. When the first flexible support layer 710, the second flexible support layer 720, and the flexible receiving substrate 730 are conveyed between the first calendering roll 741 and the second calendering roll 742, the flexible receiving substrate 730 is positioned between the first flexible support layer 710 and the second flexible support layer 720. The calendering rolls 741 and 742 apply substantial pressure to the flexible support layers 710 and 720 and the flexible receiving substrate 730, causing an SIDT stack 255, including a lithium metal layer 250 and at least a portion of a seed layer 220 formed on each of the flexible support layers 710 and 720, to be transferred to the flexible receiving substrate 730.

[0101] The lamination transfer system 700 includes a first flexible support layer pick-up hub 716. Pick-up rollers 712 of the first flexible support layer 710 are positioned on the first flexible support layer pick-up hub 716. When the first flexible support layer 710 is wound onto the first flexible support layer pick-up hub 716, the SIDT stack 255 is no longer on the first flexible support layer 710 because the SIDT stack 255 previously on the first flexible support layer 710 has been transferred by the calendering unit 740 to the flexible receiving substrate 730.

[0102] The lamination transfer system 700 includes a second flexible support layer pick-up hub 726. Pick-up rollers 722 of the second flexible support layer 720 are positioned on the second flexible support layer pick-up hub 726. When the second flexible support layer 720 is wound onto the second flexible support layer pick-up hub 726, the SIDT stack 255 is no longer on the second flexible support layer 720 because the SIDT stack 255 previously on the second flexible support layer 720 has been transferred by the calendering unit 740 to the flexible receiving substrate 730.

[0103] The lamination transfer system 700 includes a flexible substrate pickup hub 736. Pickup rollers 732 of a flexible receiving substrate 730 are positioned on the flexible substrate pickup hub 736. The flexible receiving substrate 730 includes SIDT stacks on each of its upper surface 730U and lower surface 730L. The SIDT stacks are transferred from corresponding flexible support layers 710, 720 to the flexible receiving substrate 730 by a calendering unit 740.

[0104] The lamination transfer system 700 further includes a plurality of rollers 781-788. In some implementations, each roller 781-788 may be a passive roller. During each movement of the flexible support layers 710, 720 and the flexible receiving substrate 730 through different portions of the lamination transfer system 700, the rollers 781-788 may help apply appropriate tension to the flexible support layers 710, 720 and the flexible receiving substrate 730 and help change the orientation of the flexible support layers 710, 720 and the flexible receiving substrate 730. Some of the rollers 781-788 may also help move the flexible support layers 710, 720 closer to or further away from the flexible receiving substrate 730. For example, the second roller 782 and the third roller 783 help bring the flexible support layers 710, 720 into contact with the flexible receiving substrate 730 before the flexible support layers 710, 720 and the flexible receiving substrate 730 are conveyed through the calendering unit 740. Furthermore, the fourth roller 784 and the fifth roller 785 provide positions where tension can be applied to the flexible support layers 710 and 720 to peel them off from the flexible receiving substrate 730. After the flexible support layers 710 and 720 are separated from the flexible receiving substrate 730, the sixth roller 786 and the seventh roller 787 sequentially guide the flexible support layers 710 and 720 toward corresponding flexible support layer pickup hubs 716 and 726, which can be used to recapture or retrieve the flexible support layers 710 and 720. In some implementations, one or more of the rollers 781-788 may alternatively be rods, such as metal rods, which can apply tension during the movement of the flexible support layers or the flexible substrate.

[0105] The lamination transfer system 700 may further include actuators (not shown) configured to rotate hubs 715, 716, 725, 726, 735, 736, such that the flexible support layers 710, 720 and the flexible receiving substrate 730 can be transferred from the corresponding supply hubs 715, 725, 735 through the calendering unit 740 and to the corresponding pick-up hubs 716, 726, 736. The lamination transfer system 700 may further include one or more actuators (not shown) of the calendering rollers 741, 742 of the rotating calendering unit 740. The rotational speed of the actuators can be adjusted to control the speed at which the flexible receiving substrate 730 and the flexible support layers 710, 720 are transferred through the lamination transfer system 700.

[0106] In the lamination transfer system 700, a flexible receiving substrate 730 is conveyed along a path from a supply roller 731 supported by a supply hub 735, passing through a first roller 781, between a second roller 782 and a third roller 783, between calendering rollers 741 and 742, between a fourth roller 784 and a fifth roller 785, through an eighth roller 788, and reaching a pick-up roller 732 surrounding a pick-up hub 736. The pick-up hub 736 is configured to rotate after the flexible receiving substrate 730 has passed between the first calendering roller 741 and the second calendering roller 742 and facilitates the conveying of the flexible substrate along the path. Similarly, pick-up hubs 716 and 726 are configured to rotate and facilitate the conveying of a flexible support layer along a path between the first supply hub 715 and the second supply hub 725 and the first support layer pick-up hub 716 and the second support layer pick-up hub 726.

[0107] The lamination transfer system 700 may also include a controller 705 for controlling the processes performed by the lamination transfer system 700. The controller 705 may be any type of controller used in industrial settings, such as a programmable logic controller (PLC). The controller 705 includes a processor 707, a memory 706, and input / output (I / O) circuitry 708. The controller 705 may also include one or more components (not shown), such as one or more power supplies, a clock, communication components (e.g., a network interface card), and a user interface typically found in controllers of semiconductor devices.

[0108] Memory 706 may include non-transitory memory. Non-transitory memory may be used to store programs and settings as described below. Memory 706 may include one or more readily available types of memory, such as read-only 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)).

[0109] Processor 707 is configured to execute various programs stored in memory 706, such as programs configured to execute methods 100 and 300 described herein. During the execution of these programs, controller 705 can communicate with I / O devices via I / O circuitry 708. For example, during the execution of these programs and communication via I / O circuitry 708, controller 705 can control outputs (e.g., actuators connected to different hubs and calendering units 740). Memory 706 may also include various operational settings for controlling the lamination transfer system 700. For example, settings may include speed settings for actuators connected to the hubs.

[0110] In summary, this disclosure provides a method for transferring a lithium metal layer using a seed layer formed on a flexible support layer as a release layer for transfer to a receiving substrate. Using a seed layer provides control over the thickness, chemical properties, quality, and release pressure of the release layer required to separate the lithium metal layer from the flexible support layer. After separation of the lithium metal layer from the flexible support layer, at least a portion of the seed layer is also transferred to the receiving substrate to act as a surface passivation layer for the lithium metal layer transferred to the receiving substrate. Therefore, using a seed layer provides a simple, efficient, and controllable method for achieving high-performance lithium transfer processes for forming anode film stacks or pre-lithiation. The formed anode film stack can serve as the anode structure of an energy storage device. In addition to also acting as a surface passivation layer for the transferred lithium metal layer, the seed layer described herein can be configured and designed to maintain a low impedance between the formed anode structure and the separator interface, such as less than about 200 ohms / cm. 2 The material of the seed layer can also be customized and selected based on the cost-effectiveness and chemistry of the flexible support layer and / or the specific battery chemistry and application to which the lithium metal layer is intended to be used.

[0111] Although the above description pertains to implementations of this disclosure, other and further implementations of this disclosure may be designed without departing from the basic scope of this disclosure, and the scope of this disclosure is defined by the appended claims.

Claims

1. A method for transferring a lithium metal layer, the method comprising: A seed crystal layer is formed on the flexible support layer; A lithium metal layer is deposited on the seed crystal layer; The lithium metal layer is laminated onto the flexible receiving substrate; and The lithium metal layer is separated from the flexible support layer to transfer the lithium metal layer onto the receiving substrate, wherein at least a portion of the seed layer is transferred to the receiving substrate together with the lithium metal layer to provide passivation for the lithium metal layer.

2. The method of claim 1, wherein the seed layer is formed on the flexible support layer by sputtering, reactive sputtering, evaporation, PVD, CVD, PECVD or other vapor deposition processes.

3. The method of claim 1, wherein the seed layer and the lithium metal layer are formed in a vacuum environment without breaking the vacuum.

4. The method of claim 1, wherein the flexible support layer comprises polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), poly(methyl methacrylate) (PMMA), cellulose triacetate (TAC), polypropylene (PP), polyethylene (PE), polycarbonate (PC), or multiples thereof or combinations thereof.

5. The method of claim 1, wherein the seed layer comprises LiF, Li2CO3, Ag, Bi, Sn, Ag+LiF, Bi+LiF, Sn+LiF, AgF, CxFy or a combination thereof.

6. The method of claim 1, wherein the thickness of the seed layer is between about 1 nm and about 5,000 nm.

7. The method of claim 1, wherein the portion of the seed layer transferred to the receiving substrate serves as a surface passivation layer of the lithium metal layer.

8. The method of claim 1, wherein transferring the lithium metal layer comprises applying a release pressure between about 0.3 g / cm² and about 16 g / cm² to separate the flexible support layer from the lithium metal layer.

9. The method of claim 1, wherein the seed layer comprises a plurality of sub-layers, and transferring the lithium metal layer from the flexible support layer comprises separating the sub-layers of the seed layer.

10. The method of claim 1, wherein the receiving substrate comprises one or more current collectors made of aluminum (Al), copper (Cu), zinc (Zn), nickel (Ni), cobalt (Co), manganese (Mn), chromium (Cr), stainless steel, cladding material, alloys thereof, or combinations thereof.

11. A method for forming a membrane stack for an energy storage device, the method comprising: A flexible support layer is installed in a vacuum environment; A seed crystal layer is formed above the flexible support layer, the seed crystal layer comprising LiF, Li2CO3, Ag, Bi, Sn, Ag+LiF, Bi+LiF, Sn+LiF, AgF, CxFy or a combination thereof; A lithium metal layer is deposited on the seed crystal layer, which is used to release the lithium metal layer from the flexible support layer; The lithium metal layer is laminated onto a flexible receiving substrate, the flexible receiving substrate comprising one or more current collectors made of aluminum (Al), copper (Cu), zinc (Zn), nickel (Ni), cobalt (Co), manganese (Mn), chromium (Cr), stainless steel, cladding materials, alloys thereof, or combinations thereof; and The lithium metal layer is transferred from the flexible support layer to the flexible receiving substrate to form the film stack, wherein at least a portion of the seed crystal layer is transferred together with the lithium metal layer to the flexible receiving substrate.

12. The method of claim 11, wherein the flexible support layer comprises polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), poly(methyl methacrylate) (PMMA), cellulose triacetate (TAC), polypropylene (PP), polyethylene (PE), polycarbonate (PC), or multiples thereof or combinations thereof.

13. The method of claim 11, wherein the thickness of the seed layer is between about 1 nm and about 5,000 nm.

14. The method of claim 11, further comprising preheating the lithium layer and the seed layer to a temperature between about 30 degrees Celsius and about 200 degrees Celsius before laminating the lithium metal layer onto the flexible receiving substrate.

15. A membrane stack for an energy storage device, the membrane stack comprising: Flexible receiving substrate; A lithium metal layer is disposed on the flexible receiving substrate; and A seed layer is disposed above at least a portion of the lithium metal layer, the seed layer being used to provide passivation for the portion of the lithium metal layer disposed between the seed layer and the flexible receiving substrate, wherein the lithium metal layer and the seed layer are transferred from the flexible support layer to the flexible receiving substrate, and the seed layer acts as a release layer for separating the lithium metal layer from the flexible support layer.

16. The film stack of claim 20, wherein the seed layer comprises LiF, Li2CO3, Ag, Bi, Sn, Ag+LiF, Bi+LiF, Sn+LiF, AgF, CxFy or a combination thereof.

17. The film stack of claim 15, wherein the thickness of the seed layer is between about 1 nm and about 5,000 nm.

18. The film stack of claim 15, wherein the seed layer serves as a surface passivation layer for the lithium metal layer.

19. The film stack of claim 15, wherein the impedance of the film stack is less than about 200 ohms / cm².

20. The film stack of claim 15, wherein the flexible receiving substrate comprises one or more current collectors made of aluminum (Al), copper (Cu), zinc (Zn), nickel (Ni), cobalt (Co), manganese (Mn), chromium (Cr), stainless steel, cladding material, alloys thereof, or combinations thereof.

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