Li metal battery cycle life improvement through interface metal / dielectric stack

Abstract

Alkali-containing apparatuses and methods for making alkali-containing apparatuses are provided. In one aspect, an anode electrode structure is provided. The anode electrode structure includes a current collector comprising copper and / or stainless steel, a lithium metal film formed over the current collector, and a protective film stack formed on the lithium metal film. The protective film stack includes a metal film formed over the lithium metal film and a lithium salt film formed on the metal film. The metal film is selected from a bismuth film, a tin film, a silver film or a combination thereof. And a lithium salt film formed on the metal film, the lithium salt film being selected from the group consisting of lithium sulfide, lithium oxide, lithium halide, lithium chalcogenide, lithium borohydride, or a combination thereof.

Description

Improved cycle life of Li metal batteries through interfacial metal / dielectric stacking Technical Field

[0001] This disclosure generally relates to alkali metal-containing devices and methods for manufacturing such devices. More specifically, this disclosure relates to device stacks including lithium metal anodes and pre-lithiated anodes for energy storage devices, and methods for manufacturing the same. Background Technology

[0002] Rechargeable electrochemical energy storage systems are becoming increasingly important in many areas of daily 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-scale energy storage, renewable energy storage, and uninterruptible power supplies (UPS). Traditional lead-acid / sulfuric acid batteries typically lack capacitance and often cannot cycle sufficiently for these growing applications. However, lithium-ion batteries are considered to offer the best solution.

[0003] Therefore, there is a need for methods and systems for depositing and processing lithium metal used in energy storage devices. Summary of the Invention

[0004] This disclosure generally relates to alkali metal-containing devices and methods for manufacturing such devices. More specifically, this disclosure relates to device stacks including lithium metal anodes and pre-lithiated anodes for energy storage devices, and methods for manufacturing the same.

[0005] In one aspect, an anode electrode structure is provided. The anode electrode structure includes: a current collector comprising copper and / or stainless steel; a lithium metal film formed above the current collector; and a protective film stack formed on the lithium metal film. The protective film stack includes a metal film formed above the lithium metal film and a lithium salt film formed on the metal film. The metal film is selected from bismuth film, tin film, silver film, or combinations thereof. The lithium salt film formed on the metal film is selected from lithium sulfide, lithium oxide, lithium halide, lithium chalcogenide, lithium borohydride, or combinations thereof.

[0006] The implementation may include one or more of the following. The protective film stack further includes a lithium carbonate film formed on the lithium metal film, and a metal film formed on the lithium carbonate film. The anode electrode structure further includes an anode film formed on the current collector, and a lithium metal film formed on the anode film. The metal film is a silver film. The metal film has a thickness ranging from about 50 nanometers to about 500 nanometers. The lithium salt film is a lithium fluoride film, and the lithium fluoride film has a thickness ranging from about 100 nanometers to about 500 nanometers. The current collector includes a polymer substrate and a copper film formed on the polymer substrate.

[0007] In another aspect, an energy storage device is provided. The energy storage device includes the aforementioned anode electrode structure, cathode electrode structure, and a separator membrane or solid electrolyte membrane formed between the anode electrode structure and the cathode electrode structure.

[0008] In another aspect, a method for forming an anode electrode structure is provided. The method includes forming a protective film stack over a lithium metal film, the lithium metal film being formed over a substrate. Forming the protective film stack includes forming a metal film over the lithium metal film and forming a lithium salt film on the metal film. The metal film is selected from bismuth film, tin film, silver film, or combinations thereof. The lithium salt film is selected from lithium sulfide, lithium oxide, lithium halide, lithium chalcogenide, lithium borohydride, or combinations thereof.

[0009] The implementation may include one or more of the following. The method further includes forming a lithium carbonate film on a lithium metal film before forming the protective film stack over the lithium salt film, the lithium carbonate film being formed on the lithium salt film, and the metal film being formed on the lithium carbonate film. Forming the lithium carbonate film includes exposing the lithium metal film to CO2 gas in a first processing region defined by a first processing chamber. The method further includes transferring the substrate from the first processing region to a second processing region defined by a second processing chamber, wherein the protective film stack is formed in the second processing chamber. The substrate is a current collector having an anolyte film formed thereon. Forming the metal film includes a thermal evaporation process. Forming the lithium salt film includes a thermal evaporation process. The substrate is a roll-to-roll substrate. The metal film is the silver film. The metal film has a thickness ranging from about 50 nanometers to about 500 nanometers. The lithium salt film is a lithium fluoride film having a thickness ranging from about 100 nanometers to about 500 nanometers. The substrate includes a polymer substrate and a copper film formed over the polymer substrate.

[0010] In another aspect, a method for forming a film stack for an energy storage device is provided. The method includes forming a protective film stack over a flexible support layer stack. Forming the protective film stack includes: forming a lithium salt film over a release layer; forming a metal film selected from bismuth, tin, silver, or combinations thereof on the lithium salt film; and forming a lithium metal film on the metal film. The method further includes laminating the lithium metal film to the flexible substrate stack. The method further includes separating the protective film stack from the flexible support layer stack to form an anode film stack. The lithium salt film is selected from lithium sulfides, lithium oxides, lithium halides, lithium sulfides, lithium borohydrides, or combinations thereof.

[0011] The implementation may include one or more of the following: The flexible support layer stack includes a polymer substrate having a release layer formed thereon, and the protective film stack is formed on the release layer. The flexible support layer stack includes a polymer substrate, and the protective film stack is formed on the polymer substrate. The flexible substrate stack includes a current collector containing copper. The flexible substrate stack further includes an anode film formed above the current collector, and the lithium metal film contacts the anode film. Forming the metal film includes a thermal evaporation process. Forming the lithium salt film includes a thermal evaporation process. The metal film is the silver film.

[0012] In another aspect, an anode stack is provided. The anode stack includes: a copper substrate configured to act as a current collector; a lithium layer disposed on the copper substrate and configured to act as an anode; a silver layer disposed on the lithium layer; and a lithium salt layer disposed on the silver layer, the lithium salt layer being selected from lithium sulfides, lithium oxides, lithium halides, lithium sulfides, lithium borohydrides, or combinations thereof.

[0013] The implementation may include one or more of the following: A passivation layer is disposed between the lithium layer and the silver layer. The passivation layer comprises lithium carbonate and is formed by passivating the lithium layer with carbon dioxide. The lithium salt layer comprises lithium fluoride. The lithium salt layer has a thickness of 50 nm to 600 nm. The silver layer has a thickness of 40 nm to 600 nm.

[0014] In another aspect, a method for forming an anode stack is provided. The method includes: depositing a lithium layer on a copper substrate using roll-to-roll physical vapor deposition (PVD); depositing a silver layer on the lithium layer using thermal evaporation; and depositing a lithium salt layer on the silver layer using thermal evaporation, the lithium salt layer being selected from lithium sulfides, lithium oxides, lithium halides, lithium sulfides, lithium borohydrides, or combinations thereof.

[0015] The implementation may include one or more of the following. The method further includes passivating the lithium layer using an in-situ carbon dioxide passivation process prior to depositing the silver layer. The deposition and passivation of the lithium layer are performed in a roll-to-roll PVD tool, and the deposition of the silver layer and the lithium salt layer are performed in different chambers. The method is performed in a roll-to-roll PVD tool. The lithium salt layer comprises lithium fluoride. The lithium salt layer has a thickness of 50 nm to 600 nm. The silver layer has a thickness of 40 nm to 600 nm. The method further includes integrating the anode stack with separators and a cathode structure to form an energy storage device.

[0016] In another aspect, a method for forming an anode structure is provided. The method includes: forming a release layer on a polymer substrate; depositing a lithium salt layer on the release layer disposed on the polymer substrate; depositing a silver layer on the lithium salt layer; depositing a lithium layer on the silver layer to form an anode; and transferring the anode from the polymer substrate to a copper substrate to form an anode structure, wherein the lithium salt layer is selected from lithium sulfides, lithium oxides, lithium halides, lithium sulfides, lithium borohydrides, or combinations thereof.

[0017] The implementation may include one or more of the following: The lithium salt layer comprises lithium fluoride. The lithium salt layer has a thickness of 50 nm to 600 nm. The silver layer has a thickness of 40 nm to 600 nm. The lithium layer has a thickness of 2 micrometers to 25 micrometers. The method further includes integrating the anode stack with separators and a cathode structure to form an energy storage device.

[0018] In another aspect, a non-transient computer-readable medium has instructions stored thereon that, when executed by a processor, cause a process to perform the operations of the aforementioned apparatus and / or methods. Attached Figure Description

[0019] 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 with reference to the embodiments illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate exemplary embodiments only and should therefore not be considered as limiting the scope of this disclosure, and other equally effective embodiments are appreciated.

[0020] Figure 1 illustrates a schematic cross-sectional view of an energy storage device incorporating an anode structure having a protective film stack formed according to one or more implementations described herein.

[0021] Figure 2 illustrates a cross-sectional view of a double-sided anode electrode structure having a protective film stack formed according to one or more implementations described herein.

[0022] Figure 3 illustrates a flowchart of selected operations of a method for forming an energy storage device according to one or more implementations of the present disclosure.

[0023] Figures 4A to 4D illustrate views of various stages of manufacturing an energy storage device according to the method of Figure 3 according to one or more implementations of this disclosure.

[0024] Figure 5 illustrates a flowchart of selected operations of a method for forming an energy storage device according to one or more implementations of the present disclosure.

[0025] Figures 6A to 6F illustrate views of various stages of manufacturing an energy storage device according to the method of Figure 5 according to one or more implementations of this disclosure.

[0026] Figure 7 illustrates SEM images of lithium surfaces passivated with different protective film stacks according to one or more implementations of this disclosure, and a control sample without passivation.

[0027] Figure 8 illustrates a graph of impedance data for various protective film stacks according to one or more implementations of this disclosure.

[0028] Figure 9 illustrates voltage versus time graphs according to one or more implementations of this disclosure, demonstrating lithium plating / stripping behavior of Li / Li symmetric units including various protective film stacks.

[0029] Figure 10 illustrates a graph of one or more implementations of this disclosure, showing the variation of discharge and charge capacity collected for Li / Li symmetric cells with the number of cycles.

[0030] To facilitate understanding, common elements in the figures have been designated using the same element symbols where possible. It is contemplated that elements and features of one embodiment may be beneficially incorporated into other embodiments without further elaboration. Detailed Implementation

[0031] This disclosure generally relates to alkali metal-containing devices and methods for manufacturing such devices. More specifically, this disclosure relates to device stacks including lithium metal anodes and pre-lithiated anodes for energy storage devices, and methods for manufacturing such device stacks.

[0032] Energy storage devices, such as Li-ion and sodium-ion batteries, typically include a positive electrode (e.g., cathode) and a negative electrode separated from the liquid electrolyte by a polymer separator. Solid-state batteries also typically include a positive electrode (e.g., cathode) and a negative electrode (e.g., anode), but replace the polymer separator and liquid electrolyte with ion-conducting materials. Lithium metal is considered one of the most attractive candidates due to its high capacity and low potential compared to traditionally used graphite; however, cycle life is a challenge due to lithium dendrite formation during charge and discharge. The ability to use alkali metals such as lithium and sodium in next-generation batteries, including Li-ion, sodium-ion, and solid-state batteries, is becoming increasingly important. However, alkali metal technologies present significant device integration challenges, such as handling lithium in a dry chamber environment, suitable surface protection technologies, and the need to suppress or eliminate lithium metal dendrite formation during battery cycling. For example, lithium metal is highly reactive with ambient gases such as O2, N2, and H2O under normal atmospheric conditions. From an electrochemical device perspective, it is desirable that interface materials not only help prevent oxidation of the lithium surface but also contribute to improved device performance.

[0033] Using the implementations described herein, deposited lithium metal (single-sided or double-sided) can be protected during winding and unwinding on downstream reels. Depositing one or more thin protective films as described herein offers several advantages. In some implementations, the one or more protective films described herein provide sufficient surface protection for transport, handling, and storage, and prevent surface reactions of lithium during device integration. In some implementations, the one or more protective films described herein are compatible with Li ions and reduce the impedance of ion passage. In some implementations, the one or more protective films described herein are ion-conductive and therefore can be incorporated into the formed energy storage device. In some implementations, the one or more protective films described herein may also help suppress or eliminate lithium dendrites, especially under high current density operation. In some implementations, the use of the protective films described herein reduces the complexity of the manufacturing system and is compatible with current manufacturing systems.

[0034] As described herein, flexible substrates can be considered to include, among other things, strips of films, foils, rolls, plastic materials, metals, paper, or other materials. Typically, the terms “roll,” “foil,” “strip,” “substrate,” etc., are used synonymously.

[0035] Figure 1 illustrates a schematic cross-sectional view of one implementation of an energy storage device 100, which incorporates an anode electrode structure having a protective film stack formed according to the implementation described herein. The energy storage device 100 may be a solid-state energy storage device, a sodium-ion based storage device, or a lithium-ion based energy storage device. Even though shown as a planar structure, the energy storage device 100 may be formed into a cylindrical shape by stacking wound layers; and other battery cell configurations (e.g., prismatic battery cells, coin cells, or stacked electrode battery cells) may be formed. The energy storage device 100 includes an anode electrode structure 110 and a cathode electrode structure 120, with a separator membrane 130 located therebetween. In the implementation of the energy storage device 100 as a solid-state energy storage device, the separator membrane 130 is replaced by a solid electrolyte membrane. The cathode electrode structure 120 includes a cathode current collector 140 and a cathode film 150. The anode electrode structure 110 includes an anode current collector 160, an anode film 170, and a protective film stack 180. The protective film stack 180 includes at least one or more of lithium salt film, sodium salt film, metal film (e.g., bismuth film, tin film, silver film) and lithium carbonate film.

[0036] The cathode electrode structure 120 includes a cathode current collector 140, on which a cathode film 150 is formed. It should be understood that the cathode electrode structure 120 may include other elements or films.

[0037] The separator membrane 130 may include a cellulose-based substrate, such as a blend of cellulose nanofibers and aramid fibers, as a non-limiting example only. The separator membrane 130 may include a microporous polymer separator comprising a polyolefin, as a non-limiting example only. The polyolefin may be a homopolymer (derived from a single monomer component) or a hybrid (derived from more than one monomer component), and may be linear or branched. If the hybrid is derived from two monomer components, the polyolefin may use any copolymer chain arrangement, including those of block copolymers or random copolymers. Similarly, if the polyolefin is a hybrid derived from more than two monomer components, it may also be a block copolymer or a random copolymer. In some implementations, the polyolefin may be polyethylene (PE), polypropylene (PP), a blend of PE and PP, or a multilayer 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), available from Celgard LLC. The separator membrane 130 may be or include a roll-based substrate.

[0038] Current collectors 140 and 160, located on cathode film 150 and anode film 170 respectively, may be the same or different electronic conductors. In some implementations, at least one of current collectors 140 and 160 is a flexible substrate. In some implementations, the flexible substrate is a CPP film (i.e., cast polypropylene film), an OPP film (i.e., oriented polypropylene film), or a PET film (i.e., oriented polyethylene terephthalate film). Alternatively, the flexible substrate may be pre-coated paper, polypropylene (PP) film, PEN film, polylactic acid (PLA) film, or PVC film. Examples of metals that current collectors 140 and 160 may contain 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 one or more implementations that can be combined with other implementations, at least one of current collectors 140 and 160 is perforated. In one implementation, at least one of current collectors 140 and 160 is a metallized plastic substrate, which includes a polymer substrate coated with a metallic material (e.g., polyethylene terephthalate (“PET”)). In one or more implementations that can be combined with other implementations, the anode current collector 160 is a copper-coated polymer substrate (e.g., a PET film). In another implementation, the anode current collector 160 is a multi-metal layer located on a polymer substrate. The multi-metal layer may be a combination of copper, chromium, nickel, etc. In one or more implementations that can be combined with other implementations, the anode current collector 160 is a multilayer structure including a copper-nickel cladding material. In one or more implementations that can be combined with other implementations, the multilayer structure includes a first layer of nickel or chromium, a second layer of copper formed on the first layer, and a third layer including nickel, chromium, or both formed on the second layer. In one or more implementations that can be combined with other implementations, the anode current collector 160 is nickel-plated copper. Furthermore, the current collector may have any shape factor (e.g., metal foil, mesh foil, sheet, or plate), shape, and micro / macro structure.

[0039] Typically, in prismatic cells, the tabs are formed of the same material as the current collector and can be formed during stack fabrication or added subsequently. In some implementations, the current collector extends beyond the stack, and the portion of the current collector extending beyond the stack can serve as the tab. In one or more implementations that can be combined with other implementations, the cathode current collector 140 is aluminum. In one or more implementations that can be combined with other implementations, the cathode current collector 140 comprises aluminum deposited on a polymer substrate (e.g., a PET film). In one implementation, the cathode current collector 140 has a thickness of less than 50 µm, more specifically 5 µm, or even more specifically 2 µm. In one implementation, the cathode current collector 140 has a thickness ranging from about 0.5 µm to about 20 µm (e.g., from about 1 µm to about 20 µm; from about 6 µm to about 18 µm; or from about 5 µm to about 10 µm). In one or more implementations that can be combined with other implementations, the anode current collector 160 is or includes copper. In one implementation, the anode current collector 160 is stainless steel. In one implementation, the anode current collector 160 has a thickness of less than 50 µm, more specifically 5 µm, or even more specifically 2 µm. In another implementation, the anode current collector 160 has a thickness ranging from about 0.5 µm to about 20 µm (e.g., from about 1 µm to about 10 µm; from about 2 µm to about 8 µm; from about 6 µm to about 18 µm; or from about 5 µm to about 10 µm).

[0040] The cathode film 150 or the cathode itself can be any material compatible with the anode and may include intercalating compounds, insertion compounds, or electrochemically active polymers. Suitable intercalating materials include, for example, lithium-containing metal oxides, MoS2, FeS2, BiF3, Fe2OF4, MnO2, TiS2, NbSe3, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, V6O 13 And V2O5. Suitable polymers include, for example, polyacetylene, polypyrrole, polyaniline, and polythiophene. The cathode film 150 or cathode may be made of layered oxides (such as lithium cobalt oxide), olivine-type materials (such as lithium iron phosphate), or spinel-type materials (such as lithium manganese oxide). Exemplary lithium-containing 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 Al 0.05O2, LiMn2O4, and lithium-rich layered-layered materials, where x is zero or a non-zero value. Exemplary phosphates may be fir olivine (LiFePO4) and its variants (such as LiFe...). (1-x) Mg x PO4), LiMoPO4, LiCoPO4, LiNiPO4, Li3V2(PO4)3, LiVOPO4, LiMP2O7 or LiFe 1.5 P2O7, where x is zero or a non-zero value. Exemplary fluorophosphates may be LiVPO4F, LiAlPO4F, Li5V(PO4)2F2, Li5Cr(PO4)2F2, Li2CoPO4F, or Li2NiPO4F. Exemplary silicates may be Li2FeSiO4, Li2MnSiO4, or Li2VOSiO4. An exemplary non-lithium compound is Na5V2(PO4)2F3.

[0041] The anode electrode structure 110 includes an anode current collector 160, on which an anode film 170 is formed. The anode electrode structure 110 also includes a protective film stack 180, which includes at least one or more of a lithium salt film, a sodium salt film, a metal film, and a lithium carbonate film. In some implementations, one or more protective films are ion-conducting films.

[0042] The anode membrane 170 may be any material compatible with the cathode membrane 150. The anode membrane 170 may be or include alkali metals, alkaline earth metals, and alloys thereof. The anode membrane 170 may have an energy capacity greater than or equal to 372 mAh / g, preferably ≥700 mAh / g, and most preferably ≥1000 mAh / g. The anode membrane 170 may be composed of graphite, silicon, silicon-containing graphite, silicon oxide, alkali metals (e.g., alkali metal foil or alkali metal alloy foil, such as lithium-aluminum alloy or sodium-aluminum alloy) or alkali metals and / or alkali metal alloys with materials such as carbon (e.g., coke, graphite), nickel, copper, tin, indium, silicon, and their oxides or combinations thereof. Alkali metals or alloys include alkali metals such as lithium metal, sodium, potassium, rubidium, cesium, francium, alloys including the alkali metal, or combinations thereof. The formed anode material may include or be (but is not limited to) graphite, silicon, silicon graphite, silicon oxide graphite, silicon, tin, hard carbon, metal oxides, or combinations thereof. Alloys including alkali metals may include alloys of alkali metals and anode materials. Suitable lithium-containing metal films include lithium metal, lithium metal foil, or lithium alloy foil (e.g., lithium-aluminum alloy), or mixtures of lithium metal and / or lithium alloys with materials such as carbon (e.g., coke, graphite), nickel, copper, tin, indium, silicon, and their oxides or combinations thereof. Suitable sodium-containing metal films include sodium metal, sodium metal foil, or sodium alloy foil (e.g., sodium-aluminum alloy), or mixtures of sodium metal and / or sodium alloys with materials such as carbon (e.g., coke, graphite), nickel, copper, tin, indium, tellurium, silicon, and their oxides or combinations thereof. Anode film 170 may include an intercalation compound containing lithium or sodium, or an insertion compound containing lithium or sodium. In one or more implementations that can be combined with other implementations, the anode film is a lithium metal film or a sodium metal film. In some implementations, wherein the anode film 170 includes lithium metal or sodium metal, the lithium metal or sodium metal being deposited using the methods described herein.

[0043] In one implementation, the anode film 170 has a thickness ranging from about 10 µm to about 200 µm (e.g., from about 1 µm to about 100 µm; from about 10 µm to about 30 µm; from about 20 µm to about 30 µm; from about 4 µm to about 20 µm; or from about 50 µm to about 100 µm).

[0044] In one or more implementations that can be combined with other implementations, the anode electrode structure further includes a lithium-activated tellurium film. The lithium-activated tellurium film can be used to replace the anode film 170 to form an anode-free energy storage device. The lithium-activated tellurium film can be an ultrathin lithium-activated tellurium film.

[0045] In some implementations, a protective film stack 180 is formed on the anode film 170. In some implementations, one or more protective films are ion-conducting films. In some implementations, the protective film stack 180 is permeable to at least one of lithium ions and lithium atoms. The protective film stack 180 provides surface protection for the anode film 170, which allows the anode film to be processed in a drying chamber. In some implementations where the energy storage device 100 is a solid-state energy storage device, the protective film stack 180 helps to form an improved SEI layer and thus improves device performance. The protective film stack 180 can be directly deposited on the anode film 170 by physical vapor deposition (PVD) (such as evaporation (e.g., thermal or electron beam) or sputtering), atomic layer deposition (ALD), slot casting, dip coating, planar melt spin coating, thin film transfer, gravure coating, or three-dimensional lithium printing.

[0046] In some implementations, the protective film stack 180 includes one or more metal films. Suitable metal films include, but are not limited to, tin films, bismuth films, gallium films, germanium films, copper films, silver films, gold films, bismuth alloy films, gallium alloy films, germanium alloy films, copper alloy films, silver alloy films, gold alloy films, or combinations thereof. One or more metal films may be ultrathin metal seed films.

[0047] In some implementations, the protective film stack 180 includes one or more lithium salt films. The lithium salt film may include or be a lithium salt electrolyte, a lithium salt anode coating, or a combination thereof. The electrolyte may be in a gel or polymer matrix medium. The lithium salt film may include or be a lithium sulfide, lithium oxide, lithium halide, lithium chalcogenide, lithium borohydride, or a combination thereof. Suitable lithium halide films may include or be lithium chloride films, lithium iodide films, lithium fluoride films, and lithium bromide films. Suitable examples of lithium halide films may be or include LiF, LiCl, LiBr, LiI, Li2BeF4, Li3AlF6, Li3YBr6, Li3InCl6, Li3ScCl6, Li6PS5I, Li6PS5Br, Sr2LiCBr3N2, Li3InCl6, LiErCl6, Li6PS5Cl, LiAlCl4, LiGaBr4, LiGaCl4, LiBiF4, Li6AsS5I, LiSbF4, LiHoGe2(O4F)2, LiBF4, or combinations thereof. Suitable examples of lithium oxide films may be or include Li7La3Zr2O12 (LLZO), Li7La3Hf2O12, LiErO2, LiYO2, LiLaO2, Li5AlO4, Li6PClO5, Li3AsO4, Li3PO4, Li4GeO4, Li5GaO4, Li2CO3, LiAlB2O5, Li3BiO3, LiZr2(PO4)3, LiTi2(PO4)3, Li2O, Li2HIO, Li10SiP2O12 (LiSiPO), LSnPO, or combinations thereof. Suitable examples of lithium sulfide films may include or include Li9S3N, LiAlS2, Li10Si(PS6)2, Li10SiP2S12, Li3AsS3, Li4GeS4, Li3PS4, Li3BS3, Li4TiS4, LiZnPs4, Li7P3S11, Li3PS4, Li4GeS4, Li10GeP2S12, Li2S, SrLi(BS2)3, and Li5B. 7S13, LiSO3F, Li2BS3, Li2B2S5, LiSmS2, KLiS, RbLiS, BaLiS3, Li2GePbS4, LiErS2, LiHoS2, LiDyS2, LSiPS, lithium phosphide sulfides (75Li2S-25P2S5 / β-Li3PS4), crystalline LPS (c-LPS), amorphous lithium phosphide sulfide LPS (a-LPS), or combinations thereof. Suitable examples of lithium sulfide films may be or include Li2Se, LiGaSe2, Li4SnSe4, LiInSe2, LiErSe2, or combinations thereof.Suitable lithium borohydride films may be or include LiBH4·CH3NH2, LiBH4·NH3, LiBH4·NH3BH3, [Li(CH3NH2)(BH4)3], 0.7Li(CB9H10)-0.3Li(CB11H12) or combinations thereof. Other suitable examples of lithium metal salts include Li3BN2, Sr4Li(BN2)3, Li5SiP3, LiMgB3(H9N)2, lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide, lithium bis(oxalatoborate)borate (LiBOB), lithium hexafluorophosphate (LiPF6) or combinations thereof.

[0048] In one or more examples, LiTFSI can be incorporated into a flexible solid electrolyte (CSE) membrane consisting of a polyvinylidene fluoride (PVDF) matrix, a high-concentration lithium salt (LiTFSI), a solvent (DMF), and ceramic fillers Li1.3Al0.3Ti1.7(LATP)PVDF-xLiTFSI and HFP / LiTFSI.

[0049] In one or more implementations that can be combined with other implementations, the lithium metal salt film can be formed directly on the substrate stack, for example, directly on the current collector to form an anode-free energy storage device.

[0050] In some implementations, the protective film stack 180 includes one or more sodium salt films. In one or more implementations that can be combined with other implementations, the lithium metal salt film may be replaced by a sodium salt electrolyte, a sodium salt anode coating, or used in combination with a sodium salt electrolyte and a sodium salt anode coating. The sodium salt film may be or include a nested borate / cage borate mixed anionic electrolyte. Suitable examples of nested borate / cage borate mixed anionic electrolytes may be or include NaB11H14, Na(B11H14)(B12H12)2, Nax+2y(B11H14)x(B12H12)y, Na5(B11H14)(B12H12)2, Na4(B11H14)2(B12H12), Na3(B11H14)(B12H12), Na2B12H12, or combinations thereof.

[0051] In some implementations, each layer of the protective film stack 180 is a coating or a discrete film having a thickness ranging from 1 nanometer to 3000 nanometers (e.g., ranging from 10 nanometers to 600 nanometers; ranging from 50 nanometers to 100 nanometers; ranging from 50 nanometers to 200 nanometers; ranging from 100 nanometers to 150 nanometers). In some implementations, each layer of the protective film stack 180 is a coating or a discrete film having a thickness of 500 nanometers or less (e.g., from about 1 nm to about 400 nm; from about 25 nm to about 300 nm; from about 50 nm to about 200 nm; from about 100 nm to about 150 nm; from about 10 nm to about 80 nm; or from about 30 nanometers to about 60 nanometers). In some implementations, each layer of the protective film stack 180 is a coating or discrete film with a thickness of 100 nanometers or less (e.g., from about 5 nanometers to about 100 nanometers; from about 5 nanometers to about 40 nanometers; from about 10 nanometers to about 20 nanometers; or from about 50 nanometers to about 100 nanometers).

[0052] Figure 2 illustrates a cross-sectional view of one implementation of the anode electrode structure 200 formed according to the implementation described herein. Note that in Figure 2, the anode current collector 160 is shown extending beyond the stack, although the anode current collector 160 does not necessarily extend beyond the stack; the portion extending beyond the stack can serve as a tab. Although the anode electrode structure 200 is depicted as a double-sided electrode structure, it should be understood that the implementation described herein is equally applicable to single-sided electrode structures.

[0053] The anode electrode structure 200 has an anode current collector 160 and an anode film stack 110a-b formed on opposite sides of the anode current collector 160. In one or more implementations that can be combined with other implementations, the anode film stack 110a-b includes an anode film 170a-b and a protective film stack 180a-b formed on each anode film 170a-b.

[0054] Figure 3 illustrates a flowchart of a method 300 for manufacturing an anode electrode structure 400 according to one or more implementations of the present disclosure. Figures 4A to 4D illustrate views of various stages of manufacturing the anode electrode structure 400 according to one or more implementations of the present disclosure. Although Figures 4A to 4D are described in conjunction with method 300, it will be understood that the structures disclosed in Figures 4A to 4D are not limited to method 300, but may exist independently of method 300. Similarly, although method 300 is described in conjunction with Figures 4A to 4D, it will be understood that method 300 is not limited to the structures disclosed in Figures 4A to 4D, but may exist independently of the structures disclosed in Figures 4A to 4D. It should be understood that Figures 4A to 4D only illustrate partial schematic views of the anode electrode structure 400, and the anode electrode structure 400 may include any number of additional layers and / or additional materials common to energy storage devices, which are not shown for simplicity. It should also be noted that although the method 300 illustrated in Figure 3 is described sequentially, including one or more operations that have been omitted and / or added, and / or other process sequences that have been rearranged in another suitable order, it also falls within the scope of the implementation of the present disclosure provided herein.

[0055] Referring to FIG4A, at operation 310, a flexible substrate stack 402 is provided. The flexible substrate stack 402 may include one or more layers. In some implementations, for example, for a lithium metal anode device, the flexible substrate stack 402 may include a current collector, such as current collector 160. In some implementations, for example, for a pre-lithiation process, the flexible substrate stack 402 may include an anode material. In other implementations, for a pre-lithiation process, the flexible substrate stack 402 may include both a current collector and an anode material. In yet another implementation, the flexible substrate stack 402 may be or include a separator, such as a separator film 130 as shown in FIG1. ​​The flexible substrate stack 402 may be or include a current collector, or a current collector having an anode material formed thereon. The flexible substrate stack 402 may further include an interface layer, a solid electrolyte interface (SEI) layer, or both an interface layer and an SEI layer. In one or more implementations that can be combined with other implementations, the flexible substrate stack 402 includes a roll-to-roll substrate; for example, the current collector may be a roll-to-roll substrate.

[0056] Referring to Figure 4A, at operation 320, a lithium metal film 404 is formed on the substrate. The lithium metal film 404 may be an anode film 170. In one implementation, the lithium metal film 404 is an anode film, and the flexible substrate stack 402 is an anode current collector. In one implementation, the lithium metal film 404 is formed on a copper current collector. In some implementations, if an anode film already exists on the substrate, the lithium metal film 404 is formed on the anode film. If no anode film exists, the lithium metal film 404 may be formed directly on the flexible substrate stack 402. Any suitable lithium metal film deposition process for depositing lithium metal thin films 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 vapor deposition (e.g., thermal vapor deposition or electron beam vapor deposition), trenching processes, transfer processes, spin coating processes (followed by optional melt reflow), or three-dimensional lithium printing processes. Chambers for depositing lithium metal thin films may include PVD systems, such as electron beam evaporation machines, thermal evaporation machines, or sputtering systems, thin film transfer systems (including large-area patterning systems, such as gravure printing systems), or trench deposition systems. The lithium metal film 404 can be deposited under vacuum. The lithium metal film 404 can be deposited under vacuum in a roll-to-roll deposition system.

[0057] Referring to Figure 4B, optionally, at operation 330, a first protective film 410 is formed on or above the lithium metal film 404. The first protective film 410 may be part of a protective film stack 180, and the lithium metal film 404 may be an anode film 170. In one or more implementations that can be combined with other implementations, the first protective film 410 is a passivation film. The passivation film can be used as a protective film for the lithium metal film 404. For example, the passivation layer can protect the lithium metal film 404 from oxidation and damage during storage and transportation. In one or more implementations that can be combined with other implementations, the first protective film 410 is or includes a lithium carbonate film. In some implementations, where the lithium metal film 404 is formed in a first processing chamber and then transferred to a second processing chamber to form an additional film in the stack, the lithium carbonate film serves as a passivation layer, protecting the underlying lithium metal film 404 from exposure to the atmosphere. In some implementations, where the lithium metal film 404 is not exposed to the atmosphere, the first protective film 410 may not be present. In some implementations, the first protective film 410 has a thickness of 100 nanometers or less (e.g., from about 5 nanometers to 100 nanometers; from about 10 nanometers to about 20 nanometers; or from about 50 nanometers to about 100 nanometers). The lithium carbonate film can be formed by exposing the lithium metal film 404 to carbon dioxide in the processing chamber in which the lithium metal film 404 is formed.

[0058] Referring to Figure 4C, at operation 340, a second protective film 420 is formed on or over the lithium metal film 404. The second protective film 420 may be part of the protective film stack 180. If a first protective film 410 is present, the second protective film 420 may be formed on or over the first protective film 410. In one or more implementations where the first protective film 410 is not present, the second protective film 420 may be formed directly on the lithium metal film 404. In one or more implementations, the second protective film 420 is or includes a metal film. In one or more implementations that can be combined with other implementations, the metal film is a bismuth film, a tin film, a silver film, or a combination thereof. In some implementations, the metal film is an ultrathin metal film. Any suitable metal film deposition process for depositing metal thin films can be used to deposit the metal film. The deposition of the metal film can be achieved through PVD processes such as vapor deposition (e.g., thermal evaporation or electron beam evaporation), CVD processes, trench molding processes, transfer processes, or three-dimensional lithium printing processes. The chamber for depositing the metal film may include a PVD system, such as an electron beam evaporator, a thermal evaporator, or a sputtering system, a thin film transfer system (including a large-area patterning system, such as a gravure printing system), or a groove deposition system. In a particular implementation, the second protective film 420 is a bismuth film formed by a thermal evaporation process.

[0059] In some implementations, the second protective film 420 has a thickness of 500 nanometers or less (e.g., from about 10 nm to about 500 nm; from about 25 nm to about 500 nm; from about 50 nm to about 500 nm; from about 50 nm to about 300 nm; from about 100 nm to about 150 nm; from about 10 nm to about 80 nm; or from about 30 nm to about 60 nm). In some implementations, the second protective film 420 has a thickness of 100 nanometers or less (e.g., from about 5 nm to 100 nm; from about 10 nm to about 20 nm; or from about 50 nm to about 100 nm).

[0060] Referring to Figure 4D, at operation 350, a third protective film 430 is formed on or above the second protective film 420. The third protective film 430 may be part of the protective film stack 180. In one or more implementations, the third protective film 430 is an alkali metal salt film, such as a lithium salt film or a sodium salt film. The alkali metal salt film can be deposited using any suitable alkali metal salt film deposition process for depositing alkali metal salt films. The deposition of the alkali metal salt film can be performed by PVD processes, such as vapor deposition (e.g., thermal vapor deposition or electron beam vapor deposition), CVD processes, trench deposition processes, transfer processes, or three-dimensional lithium printing processes. The chamber for depositing the alkali metal salt film may include a PVD system, such as an electron beam vapor deposition machine, a thermal vapor deposition machine, or a sputtering system, a thin film transfer system (including large-area patterning printing systems, such as gravure printing systems), or a trench deposition system. In a particular implementation, the third protective film 430 is a lithium fluoride film formed by a thermal vapor deposition process.

[0061] In one or more implementations that can be combined with other implementations, the third protective film 430 may be formed directly on the flexible substrate stack 402, for example, directly on the current collector to form an anode-free energy storage device.

[0062] In some implementations, the third protective film 430 has a thickness of 500 nanometers or less (e.g., from about 10 nm to about 500 nm; from about 25 nm to about 500 nm; from about 50 nm to about 500 nm; from about 50 nm to about 300 nm; from about 100 nm to about 150 nm; from about 10 nm to about 80 nm; or from about 30 nm to about 60 nm). In some implementations, the third protective film 430 has a thickness of 100 nanometers or less (e.g., from about 5 nm to 100 nm; from about 10 nm to about 20 nm; or from about 50 nm to about 100 nm).

[0063] The anode electrode stack may be integrated with a cathode structure (e.g., cathode electrode structure 120), a separator (e.g., separator membrane 130), or both a cathode structure and a separator to form an energy storage device, such as the energy storage device 100 shown in FIG1.

[0064] Figure 5 illustrates a flowchart of a method 500 for manufacturing an energy storage device 600 according to one or more implementations of the present disclosure. Figures 6A to 6F illustrate views of various stages of manufacturing the energy storage device 600 according to one or more implementations of the present disclosure. Although Figures 6A to 6F are described in conjunction with method 500, it will be understood that the structures disclosed in Figures 6A to 6F are not limited to method 500, but may exist independently of method 500. Similarly, although method 500 is described in conjunction with Figures 6A to 6F, it will be understood that method 500 is not limited to the structures disclosed in Figures 6A to 6F, but may exist independently of the structures disclosed in Figures 6A to 6F. It should be understood that Figures 6A to 6F only illustrate partial schematic views of the energy storage device 600, and the energy storage device 600 may include any number of additional layers and / or additional materials common to energy storage devices, which are not shown for simplicity. It should also be noted that although the method 500 illustrated in Figure 5 is described sequentially, including one or more operations that have been omitted and / or added, and / or other process sequences that have been rearranged in another suitable order, it also falls within the scope of the implementation of the present disclosure provided herein.

[0065] Referring to Figure 6A, at operation 510, a flexible support layer stack 602 is provided. The flexible support layer stack 602 includes a flexible support layer 610. The flexible support layer 610 has a front face 610f (also referred to as the front surface) and a back face 610b (also referred to as the rear surface) opposite the front face 610f. The flexible support layer 610 may include any suitable material compatible with the target processing conditions. In some implementations, the flexible support layer 610 includes multiple sublayers. In one or more implementations that can be combined with other implementations, the flexible support layer 610 may be or include one or more layers selected from plastics, polymeric materials, metallized plastics, metals, paper, multilayers thereof, or combinations thereof. Suitable polymeric materials include those that are laser-transparent and have low to no photon absorption to prevent overhead heating and ignition events. Examples of suitable polymeric materials include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polymethyl methacrylate (PMMA), cellulose triacetate (TAC), polypropylene (PP), polyethylene (PE), polycarbonate (PC), multilayers thereof, or combinations thereof. In one or more implementations that can be combined with other implementations, the flexible support layer 610 is a roll-based substrate.

[0066] In one or more implementations that can be combined with other implementations, the flexible support layer 610 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.

[0067] The flexible support layer stack 602 may further include a release layer 620. As shown in FIG6A, the release layer 620 may be formed on the front side 610f of the flexible support layer 610. The release layer 620 has a front side 620f (also referred to as the front surface) and a back side 620b (also referred to as the rear surface) opposite the front side 620f. In one or more implementations, the release layer 620 is deposited on the front side 610f of the flexible support layer 610 such that the back side 620b of the release layer 620 contacts the front side 610f of the flexible support layer 610. The release layer 620 can be formed on the front side of the flexible support layer 610 using any suitable process. The release layer 620 can be deposited using a non-vacuum coating technique, such as a coating technique performed in the atmosphere. In one or more implementations that can be combined with other implementations, the release layer 620 and the flexible support layer 610 are pre-prepared.

[0068] Release layer 620 may be or include any material suitable for releasing subsequently formed material from flexible support layer 610 during substrate-independent direct transfer (SIDT) processes. Release layer 620 may be or include polymer release layers (e.g., plastics, silicones, polymethyl methacrylate (PMA), polyethylene terephthalate (PET), fluorocarbons, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), etc.), polyolefin sulfones, organic materials, inorganic materials, and other materials. In some implementations that can be combined with other implementations, release layer 620 includes one or more nanosheets, such as one or more two-dimensional (2D) materials. In one or more implementations that can be combined with other implementations, the release layer has a thickness of about 1 nm to about 500 nm, such as about 10 nm to about 300 nm, such as about 50 nm to about 200 nm. In some implementations, the release layer includes multiple sublayers, each having a thickness of about 5 nm or less. Organic or polymer-based release layers can be deposited using wet chemical coating processes, such as slot die coating, comma bar coating, or gravure coating, or vacuum deposition techniques as described herein. Release layer 620 may be or comprise inorganic materials, such as BN, AlOx, AlOOH, Al, or combinations thereof. In certain implementations, release layer 620 comprises a multilayer structure, such as an Al / AlOx / AlOOH multilayer structure. Inorganic-based release layers can be deposited using vapor deposition techniques, such as PVD techniques like sputtering deposition and electron beam deposition.

[0069] In one or more implementations, each layer may have an equal and / or decreasing melting point with each added layer, such that the flexible support layer 610 has the highest melting point, the release layer 620 has a lower melting point than the flexible support layer 610, and subsequent deposited layers have even lower melting points.

[0070] Referring to Figure 6B, at operation 520, a third protective film 430 is formed over the flexible support layer stack 602. In one or more implementations where a release layer 620 is present, the third protective film 430 may be formed directly on the release layer 620. In one or more implementations, as shown in Figure 6B, the third protective film 430 is formed directly on the front side 620f of the release layer 620. In one or more implementations where the release layer 620 is absent, the third protective film 430 may be formed directly on the front side 610f of the flexible support layer 610. The third protective film 430 may be a lithium salt film or a sodium salt film as described herein. In one or more implementations, operation 520 includes a thermal evaporation process for forming the third protective film 430.

[0071] Referring to Figure 6C, at operation 530, a second protective film 420 is formed over the flexible support layer stack 602. In one or more implementations where a third protective film 430 is present, the second protective film 420 may be formed directly on top of the third protective film 430. The second protective film 420 may be a metal film as described herein. In one or more implementations, operation 530 includes a thermal vapor deposition process for forming the second protective film 420. The third protective film 430 and the second protective film 420 form a protective film stack 604.

[0072] Referring to Figure 6D, at operation 540, an alkali metal layer, such as a lithium metal film 404, is formed over the flexible support layer stack 602 and the protective film stack 604. The lithium metal film 404 has a front surface 404f (also referred to as the front surface) and a back surface 404b (also referred to as the rear surface) opposite the front surface 404f. In one or more implementations where a release layer 620 is present, the lithium metal film 404 may be formed directly on the release layer 620. In one or more implementations, as shown in Figure 6D, the lithium metal film 404 is formed directly on the second protective film 420. The lithium metal film 404 may be or include lithium. In one or more implementations, operation 540 includes a vapor deposition process for forming the lithium metal film 404. The vapor deposition process may be an electron beam vapor deposition process or a thermal vapor deposition process.

[0073] In one or more implementations, the lithium metal film 404 may be part of the SIDT film stack 635. Referring to Figure 6D, although the SIDT film stack 635 is shown as comprising only the lithium metal film 404 and the protective film stack 604, the SIDT film stack 635 typically includes additional layers, such as additional protective layers, interface layers, and solid electrolyte interphase (SEI) layers. If the SIDT film stack 635 is present, the lithium metal film 404 is typically deposited last during the formation of the SIDT film stack 635. Last deposition of the lithium metal film 404 allows the SIDT film stack 635 to be formed without damaging the lithium metal film 404, which typically has a lower melting point than other materials formed in the energy storage device. Conventional methods for forming energy storage devices typically include depositing molten lithium directly onto a current collector during lithium metal anode formation, or depositing it onto an anode material in a pre-lithiation implementation. These methods also include maintaining the underlying substrate during the formation of the lithium metal film 404 to prevent damage to the lithium. In contrast, the SIDT film stack 635 and method described herein enable the final formation of the lithium metal film 404 before transferring the SIDT film stack 635 from the flexible support layer stack 602 to the flexible substrate stack 640.

[0074] In one or more implementations that can be combined with other implementations, a solid electrolyte interface (SEI) layer may optionally be included in the SIDT film stack 635. In some implementations, the solid electrolyte interface layer may include or be a metal salt, such as a lithium salt as described herein. The lithium salt may be one or more of LiPF6, LiAsF6, LiCF3SO3, LiN(CF3SO3)3, LiBF6, LiClO4BETTE electrolytes, or combinations thereof. The electrolyte may be in a gel or polymer matrix medium. In one or more implementations, the solid electrolyte interface layer 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 (e.g., Li(1+x)Ta2P(1-x)SixO8, Li1.5Ta2P0.5Si0.5O8), lithium tantalum phosphate (e.g., LiTa2PO8(LTPO), Li2Ta2SiO8(LTSO)), Li0.34La0.56TiO3, lithium aluminum titanium phosphate (e.g., Li1.3Al0.3Ti1.7(PO4)3(LATP)), lithium aluminum germanium phosphate (e.g., Li1.3Al0.3Ge1.7(PO4)3(LAGP)), garnet Li7La3Zr2O12(LLZO), or combinations thereof.

[0075] In one or more implementations that can be combined with other implementations, an interface layer may optionally be included in the SIDT film stack 635. The interface layer may include at least one of an interface dielectric material, a plating and release reinforcement layer, and a lithiophilic layer. The interface layer is deposited under vacuum. The interface layer may be deposited under vacuum in a roll-to-roll deposition system. The interface dielectric layer may be selected from AlOx, AlOOH, LiF, BaTiO3, ZrO2, TiO2, Li4Ti5O12, LiAlO2, AlF3, BiF3, AgFx, rare earth (RE) nickelates RENiO3, or combinations thereof. RE may be trivalent rare earth elements. RE may be lanthanides. RE may be selected from La, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Y, Lu, or combinations thereof. The plating and release reinforcement layer may be selected from a metal, a metal alloy, or a metal chalcogenide. The plating and stripping reinforcement layers can be selected from Ag, Bi, Sn, Si, Ga, In, alloys of these metals, or chalcogenides of Ag, Bi, Sn, Si, Ga, In, or combinations thereof. Alkali metals or their alloys, such as lithium metal or its alloys, are deposited. The interface layer and the alkali metal layer or their alloy can be deposited without disrupting the vacuum.

[0076] In one or more implementations that can be combined with other implementations, the flexible support layer stack 602 and the lithium metal film 404 are pre-fabricated. In other implementations, the flexible support layer stack 602 is pre-fabricated, and the lithium metal film 404 is formed on the flexible support layer stack 602 via a deposition process (e.g., physical vapor deposition (PVD) process).

[0077] After operation 540 and before operation 550, the flexible support layer stack 602 on which the SIDT film stack 635 is formed can be transferred from a vacuum coating system (e.g., a roll-to-roll coating apparatus) to a lamination transfer apparatus, such as a lamination transfer system. The lamination transfer process of operation 540 may include applying the flexible substrate stack 640 onto the front side 404f of the lithium metal film 404 and removing the flexible support layer 610 and optionally the release layer 620 from the lithium metal film 404 to form the anode film stack 645 as shown in FIG. 6E.

[0078] Referring to Figure 6E, at operation 550, the SIDT film stack 635 is laminated to the flexible substrate stack 640. The flexible substrate stack 640 may include one or more layers. In some implementations, for example, for a lithium metal anode device, the flexible substrate stack 640 may include a current collector, such as current collector 160. In some implementations, for example, for a pre-lithiation process, the flexible substrate stack 640 may include an anode material, such as an anode film 170. In other implementations, for a pre-lithiation process, the flexible substrate stack 640 may include both a current collector and an anode material. In yet another implementation, the flexible substrate stack 640 may be or include a separator, such as a separator film 130 as shown in Figure 1. The flexible substrate stack 640 may be or include a current collector, or a current collector having an anode material formed thereon. In one or more implementations that can be combined with other implementations, the flexible substrate stack 640 includes a roll-to-roll substrate; for example, the current collector may be a roll-to-roll substrate. During the lamination process at operation 550, the lithium metal film 404 of the SIDT film stack 635 comes into contact with the flexible substrate stack 640. For example, as shown in FIG6E, the front side 404f of the lithium metal film 404 comes into contact with the surface of the flexible substrate stack 640. In one or more implementations where the flexible substrate stack 640 includes only a current collector, the front side 404f of the lithium metal film 404 comes into contact with the surface of the current collector. In one or more implementations where the flexible substrate stack 640 includes an anode material, the front side 404f of the lithium metal film 404 comes into contact with the surface of the anode material to pre-lithiate the anode material.

[0079] Optionally, during operation 550, pressure is applied to one or more of the flexible substrate stack 640 and the flexible support layer stack 602 on which the SIDT film stack 635 is formed to laminate the flexible substrate stack 640 to the lithium metal film 404. In one or more implementations of method 500 performed in a roll-to-roll apparatus, the roll tension is sufficient to laminate the lithium metal film 404 to the flexible substrate stack 640, and no additional pressure is required. In one or more implementations of using additional pressure to laminate the lithium metal film 404 to the flexible substrate stack 640, the lamination process includes pressing the lithium metal film 404 to the flexible substrate stack 640 with a pressure sufficient to attach the lithium metal film 404 to the flexible substrate stack 640 without damaging the lithium metal film 404. In other words, the pressure is such that the lithium metal film 404 is not mechanically damaged or degraded, such as cracking or crushing. Any suitable technique can be used to apply the pressure. In one or more implementations, the pressure is applied via a rolling process. For example, pressure can be applied to the back surface 610b of the flexible support layer 610 and the back surface 640b of the flexible substrate stack 640. 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.

[0080] Referring to FIG. 6F, at operation 560, the lithium metal film 404 separates from the flexible support layer stack 602 to form an anode film stack 645 including a SIDT film stack 635 formed on the flexible substrate stack 640. In one or more implementations that can be combined with other implementations, a portion of the release layer 620 may be transferred or partially transferred along with the lithium metal film 404. Alternatively, in other implementations, after operation 560, the release layer 620 remains or is partially retained on the flexible support layer 610.

[0081] At operation 570, the anode membrane stack 645 may be integrated with a cathode structure (e.g., cathode electrode structure 120), a separator (e.g., separator membrane 130), or both a cathode structure and a separator to form an energy storage device, such as the energy storage device 100 shown in FIG1.

[0082] Example:

[0083] The following non-limiting examples are provided to further illustrate the implementations described herein. However, these examples are not intended to be exhaustive or to limit the scope of the implementations described herein.

[0084] Lithium metal is highly reactive with ambient gases such as O2, N2, and H2O under normal atmospheric conditions. In the following examples, both unmodified and modified lithium metal samples were removed from a drying chamber where the material was kept stable and then exposed to ambient conditions for 15 minutes. The results showed that the unmodified sample reacted extremely rapidly after being removed from the drying chamber, forming a dark silver hue, which eventually turned black within minutes. This is not surprising, as lithium reacts rapidly to form LiOH, Li3N, and Li2CO3, as is known in the literature. On the other hand, the lithium surface modified with the protective layer stack described herein remained stable with minimal degradation / color change. The results indicate that the protective layer stack described herein effectively protects lithium metal from environmental influences. Furthermore, the protective layer stack described herein allows for the transport and delivery of the lithium metal film, thereby maintaining the activity of the underlying lithium metal and enabling its use in electrochemical performance.

[0085] Materials: Labelled as Type A (LiF), Type B (bismuth), Type C (silver), Type D (tin), and Type E (LTO), as well as stacks of combinations of tested coating material layers. Results are summarized in Table I below. Table I shows the tested thickness ranges and coating methods for each material.

[0086]

[0087] Table I.

[0088] Process Start-up: Process start-up begins with film thickness calibration, followed by initial sample deposition. Type A, Type B, Type C, Type D, Type E and stacked layer coatings of different thicknesses are deposited onto LiCu foil (single-sided, with both lithium and Cu foils having a thickness of 18 µm).

[0089] Characterization of the protective layer: SEM images of the initial samples were taken, and the results are shown in Figure 7. Note that all samples underwent in-situ CO2 treatment, forming a thin Li2CO3 film of approximately <40 nm on the control samples. For the passivated samples, there were obvious signs of material coating, and the structural morphology changed to varying degrees depending on the protective layer. In some cases, the lithium metal profile was masked. Surface roughness data are shown in Table II. Table II includes the surface roughness parameters of the modified samples and compares them with the control samples. The initial data indicate that the roughness of the samples did not increase significantly after the protective stack passivation described herein. Button cells were fabricated and tested to determine the cell impedance and performance.

[0090]

[0091] Table II

[0092] Button Battery Preparation and Testing

[0093] Manually cut out 1 cm using an 11.3 mm diameter punch. 2 Electrodes. Button cells were assembled using SUS3130L Ni-plated caps and battery cases. In symmetrical cells, the anode was used for both electrodes; however, in half-cells, the anode was used only as the positive electrode, and the counter electrode was a single-sided 11μm lithium electrode on copper foil. The electrolyte (1.0 M LiPF6 dissolved in EC / DEC (volume ratio 1:1) + 2% FEC), also known as AM-4, was formulated by Applied Materials and used as is. CELGARD® 2500 was used as a separator. The separator was wetted with approximately 3 drops of electrolyte solution. All cells were then pressed and sealed for 2.5 seconds using a standard battery sealer after assembly.

[0094] Electrochemical impedance spectroscopy (EIS)

[0095] EIS (Bio-Logic) tests were performed on symmetrical cells in a dual-cell configuration using a 5 mV perturbation, scanning from 10 MHz to 1 MHz. Figure 8 shows the impedance data and Nyquist impedance plots of the assembled cells. The A+B, A+D, and E-type stack designs had the highest total impedance, while the control and A+C types had the lowest total impedance, with the remaining data falling between the two. The inset of Figure 8 shows the impedance values ​​at 150 Hz. The samples in the green area of ​​the inset of Figure 8 (control, A+C, B, and C types) have impedances below 250 Ω·cm. 2The remaining samples fell into the red-marked area (>400 Ω·cm). 2 Note that the values ​​for the control sample and type A+C were the lowest at all frequencies. Low impedance and high current density (>3 mAh / cm²) were achieved. 2 A good balance between cyclical behaviors under ( ) is selected as the success criterion.

[0096] Electrochemical cycle

[0097] Before performing capacity and cycle tests using the Maccor 4600 series battery tester, the batteries were allowed to rest for 24 hours. Figure 9 shows the lithium plating / stripping behavior of symmetrical batteries at 0.2, 2, and 3 mA / cm². 2 The battery was charged and discharged for 15 minutes at a current density, with voltage limits of ±1 V, similar to the required formation cycle conditions. Typical lithium plating / stripping voltage-time curves for Li / Li symmetric batteries are shown, comparing the control sample with those of Type A+C, Type A, Type B, Type C, Type D, and Type E protective layers. The black curve corresponds to the control sample, the red curve to Type A+C, and the others to other samples. Long-term cycling tests were then conducted at the target current density. Figure 10 shows the change in battery discharge and charge capacity with the number of cycles. After approximately 140 charge-discharge cycles, or when the capacity decays to zero as shown in Figure 10, Type A+B, shown by the green curve in Figure 10, exhibited the best cycling performance, exceeding 100 cycles; the other samples experienced short circuits earlier. The control sample, shown by the orange curve, performed the worst compared to all samples. The charge-discharge cycle current density was 3.0 mA / cm². 2 .

[0098] The aforementioned implementations of this disclosure have numerous advantages. However, this disclosure does not require that all beneficial features and advantages be incorporated into every implementation of this disclosure.

[0099] Specific features (including method steps) of this disclosure are mentioned in the abstract, detailed description, claims, and drawings. It should be understood that the disclosure herein includes all possible combinations of such specific features. For example, a specific feature disclosed in a particular aspect or implementation of this disclosure or in a particular claim may also be used, to a feasible extent, in combination with other specific aspects and implementations of this disclosure, and / or in the context of other specific aspects and implementations of this disclosure, and within the overall scope of this disclosure.

[0100] In this document, the term "at least" followed by a numerical value indicates the beginning of a range starting from that value (the range may have an upper limit or no upper limit, depending on the defined variable). For example, "at least 1" means 1 or greater than 1. The term "at most" followed by a numerical value indicates the end of a range ending at that value (the lower limit of the range may be 1 or 0, or no lower limit, depending on the defined variable). For example, "at most 4" means 4 or less than 4, and "at most 40%" means 40% or less than 40%. In this specification, when a range is expressed as "(first value) to (second value)" or "(first value) - (second value)", this indicates that the lower limit of the range is the first value and the upper limit is the second value. For example, 25 to 100 mm means a range with a lower limit of 25 mm and an upper limit of 100 mm.

[0101] The embodiments and all functional operations described herein can be implemented using digital electronic circuit systems or computer software, firmware, or hardware (including the structural means disclosed herein and their structural equivalents) or combinations thereof. The embodiments described herein can be implemented as one or more non-transient computer program products, i.e., one or more computer programs tangibly embodied in a machine-readable storage device for execution or control of their operation by a data processing apparatus (e.g., a programmable processor, a computer, or a plurality of processors or computers).

[0102] The process and logic flow described in this specification can be implemented by one or more programmable processors executing one or more computer programs, which perform functions by manipulating input data and generating outputs. The process and logic flow can also be implemented by a special-purpose logic circuit system (e.g., a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC)), and the device can also be implemented as such a special-purpose logic circuit system.

[0103] The term "data processing apparatus" encompasses all means, devices, and machines used for processing data, including, for example, programmable processors, computers, or multiple processors or computers. In addition to hardware, the apparatus may also include code that creates an execution environment for the associated computer program, such as code constituting processor firmware, protocol stacks, database management systems, operating systems, or combinations thereof. Processors suitable for executing computer programs include, for example, general-purpose and special-purpose microprocessors, and any one or more processors of any kind of digital computer.

[0104] Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and storage devices, such as semiconductor storage devices like EPROM, EEPROM, and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM optical disks. Processors and memory may be supplemented or integrated therein by dedicated logic circuitry systems.

[0105] The terms “comprising,” “including,” “having,” and their grammatical equivalents, as used herein, are intended to indicate that other components, ingredients, operations, etc., may optionally be present. For example, an article that “comprising” (or “comprising”) components A, B, and C may consist of only components A, B, and C, or may contain not only components A, B, and C, but also one or more other components. Furthermore, regardless of whether the transitional phrase “comprising” or its grammatical equivalent is used before a composition, element, or group of elements, it should be understood that the same composition or group of elements may also be described using the transitional phrases “essentially composed of,” “composed of,” “selected from,” or “is,” and vice versa.

[0106] When this document refers to a method that includes two or more qualified operations, the qualified operations may be performed in any order or simultaneously (unless the context precludes this possibility), and the method may include one or more other operations that may be performed before any qualified operation, between two qualified operations, or after all qualified operations (unless the context precludes this possibility).

[0107] When introducing elements of this disclosure or its exemplary aspects or embodiments, the articles “a,” “an,” “the,” and “the” are intended to indicate the presence of one or more of the elements.

[0108] Although the foregoing describes embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from its essential scope, the scope of which is defined by the appended claims.

Claims

1. An anode electrode structure, comprising: current collector, Contains copper and / or stainless steel; A lithium metal film is formed above the current collector; And a protective film stack formed on the lithium metal film, including: a metal film formed above the lithium metal film, the metal film being selected from bismuth film, tin film, silver film or a combination thereof; And a lithium salt film formed on the metal film, the lithium salt film being selected from lithium sulfides, lithium oxides, lithium halides, lithium sulfides, lithium borohydrides, or combinations thereof.

2. The anode electrode structure of claim 1, wherein the protective film stack further comprises a lithium carbonate film formed on the lithium metal film, and the metal film formed on the lithium carbonate film.

3. The anode electrode structure of claim 1, further comprising an anode film formed on the current collector, and the lithium metal film formed on the anode film.

4. The anode electrode structure as described in claim 1, wherein the metal film is the silver film.

5. The anode electrode structure of claim 1, wherein the metal film has a thickness ranging from about 50 nanometers to about 500 nanometers.

6. The anode electrode structure of claim 5, wherein the lithium salt film is a lithium fluoride film having a thickness in the range of about 100 nanometers to about 500 nanometers.

7. The anode electrode structure of claim 1, wherein the current collector comprises a polymer substrate and a copper film formed on the polymer substrate.

8. An energy storage device, comprising: The anode electrode structure as described in any one of claims 1 to 7; Cathode electrode structure; And a separator membrane or solid electrolyte membrane is formed between the anode electrode structure and the cathode electrode structure.

9. A method for forming an anode electrode structure, comprising: A protective film stack is formed over a lithium metal film, the lithium metal film being formed over a substrate. Forming the protective film stack includes: forming a metal film over the lithium metal film, the metal film being selected from bismuth film, tin film, silver film, or combinations thereof; and forming a lithium salt film on the metal film, the lithium salt film being selected from lithium sulfide, lithium oxide, lithium halide, lithium sulfide, lithium borohydride, or combinations thereof.

10. The method of claim 9, further comprising: A lithium carbonate film is formed on a lithium metal film before the protective film stack is formed on the lithium salt film, and the metal film is formed on the lithium carbonate film.

11. The method of claim 10, wherein forming the lithium carbonate film comprises exposing the lithium metal film to CO2 gas in a first processing region defined by the first processing chamber.

12. The method of claim 11, further comprising transferring the substrate from the first processing region to a second processing region defined by a second processing chamber, wherein the protective film is stacked in the second processing chamber.

13. The method of claim 9, wherein the substrate is a current collector having an anode film formed thereon.

14. The method of claim 9, wherein forming the metal film comprises a thermal evaporation process.

15. The method of claim 14, wherein forming the lithium salt film comprises a thermal evaporation process.

16. The method of claim 9, wherein the substrate is a roll-to-roll substrate.

17. The method of claim 9, wherein the metal film is the silver film.

18. The method of claim 9, wherein the metal film has a thickness ranging from about 50 nanometers to about 500 nanometers.

19. The method of claim 18, wherein the lithium salt membrane is a lithium fluoride membrane having a thickness in the range of about 100 nanometers to about 500 nanometers.

20. The method of claim 9, wherein the substrate comprises a polymer substrate and a copper film formed over the polymer substrate.

21. A method for forming a membrane stack for an energy storage device, comprising: A protective film stack is formed over a flexible support layer stack. Forming the protective film stack includes: forming a lithium salt film over a release layer; forming a metal film on the lithium salt film, the metal film being selected from bismuth film, tin film, silver film, or combinations thereof; and forming a lithium metal film on the metal film; laminating the lithium metal film onto the flexible substrate stack; and separating the protective film stack from the flexible support layer stack to form an anode film stack, the lithium salt film being selected from lithium sulfide, lithium oxide, lithium halide, lithium sulfide, lithium borohydride, or combinations thereof.

22. The method of claim 21, wherein the flexible support layer stack comprises a polymer substrate having a release layer formed thereon, and the protective film stack is formed on the release layer.

23. The method of claim 21, wherein the flexible support layer stack comprises a polymer substrate, and the protective film stack is formed on the polymer substrate.

24. The method of claim 21, wherein the flexible substrate stack includes a current collector comprising copper.

25. The method of claim 24, wherein the flexible substrate stack further comprises an anode film formed above the current collector, and the lithium metal film is in contact with the anode film.

26. The method of claim 21, wherein forming the metal film comprises a thermal evaporation process.

27. The method of claim 26, wherein forming the lithium salt film comprises a thermal evaporation process.

28. The method of claim 26, wherein the metal film is the silver film.

29. An anode stack, comprising: The copper substrate is configured to act as a current collector; A lithium layer is disposed on the copper substrate and configured to act as an anode; A silver layer is disposed on the lithium layer; A lithium salt layer is disposed on the silver layer, wherein the lithium salt layer is selected from lithium sulfides, lithium oxides, lithium halides, lithium sulfides, lithium borohydrides, or combinations thereof.

30. The anode stack of claim 29, wherein the passivation layer is disposed between the lithium layer and the silver layer.

31. The anode stack of claim 30, wherein the passivation layer comprises lithium carbonate and is formed by passivating the lithium layer with carbon dioxide.

32. The anode stack of claim 29, wherein the lithium salt layer comprises lithium fluoride.

33. The anode stack of claim 29, wherein the lithium salt layer has a thickness of 50 nm to 600 nm.

34. The anode stack of claim 29, wherein the silver layer has a thickness of 40 nm to 600 nm.

35. A method for forming an anode stack, comprising: A roll-to-roll physical vapor deposition (PVD) tool is used to deposit a lithium layer on a copper substrate; A silver layer is deposited on the lithium layer using thermal evaporation. And using thermal evaporation to deposit a lithium salt layer on the silver layer, the lithium salt layer being selected from lithium sulfides, lithium oxides, lithium halides, lithium sulfides, lithium borohydrides, or combinations thereof.

36. The method of forming an anode stack as described in claim 35, further comprising: The lithium layer was passivated using an in-situ carbon dioxide passivation process prior to the deposition of the silver layer.

37. The method of forming an anode stack as claimed in claim 36, wherein the deposition of the lithium layer and the passivation of the lithium layer are performed in the roll-to-roll PVD tool, and the deposition of the silver layer and the lithium salt layer are performed in different chambers.

38. The method of forming an anode stack as described in claim 35, wherein the method is performed in the roll-to-roll PVD tool.

39. The method of forming an anode stack as described in claim 35, wherein the lithium salt layer comprises lithium fluoride.

40. The method of forming an anode stack as described in claim 35, wherein the lithium salt layer has a thickness of 50 nm to 600 nm.

41. The method of forming an anode stack as described in claim 35, wherein the silver layer has a thickness of 40 nm to 600 nm.

42. The method of forming an anode stack as described in claim 35, further comprising: The anode stack is integrated with separators and cathode structures to form an energy storage device.

43. A method for forming an anode structure, comprising: A release layer is formed on the polymer substrate; A lithium salt layer is deposited on the release layer disposed on the polymer substrate; A silver layer is deposited on the lithium salt layer; A lithium layer is deposited on the silver layer to form the anode; And transferring the anode from the polymer substrate to the copper substrate to form an anode structure, wherein the lithium salt layer is selected from lithium sulfides, lithium oxides, lithium halides, lithium sulfides, lithium borohydrides, or combinations thereof.

44. The method of forming an anode stack as described in claim 43, wherein the lithium salt layer comprises lithium fluoride.

45. The method of forming an anode stack as described in claim 43, wherein the lithium salt layer has a thickness of 50 nm to 600 nm.

46. ​​The method of forming an anode stack as described in claim 43, wherein the silver layer has a thickness of 40 nm to 600 nm.

47. The method of forming an anode stack as described in claim 43, wherein the lithium layer has a thickness of 2 micrometers to 25 micrometers.

48. The method of forming an anode stack as described in claim 43, further comprising: The anode stack is integrated with separators and cathode structures to form an energy storage device.

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