Composite interlayer for lithium metal-based solid-state battery packs and its preparation method

Abstract

Composite material interlayer for lithium metal-based solid-state battery packs and its preparation method. A cyclic lithium-ion solid-state electrochemical battery. The electrochemical battery may include a solid electrolyte defining a first main surface and a negative electrode defining a second main surface. The electrochemical battery may also include an interface layer disposed between the first main surface of the solid electrolyte and the second main surface of the solid electrode. The interface layer may include an ion conductor disposed in an organic matrix.

Description

[0001] Government funding

[0002] This invention was carried out with government support under license number DE-EE0008863 granted by the US Department of Energy. The government may have certain rights to this invention. Technical Field

[0003] This invention relates to a solid-state electrochemical battery for cycling lithium ions and a method for manufacturing a solid-state electrochemical battery for cycling lithium ions. Background Technology

[0004] This section provides background information relating to this disclosure, which is not necessarily prior art.

[0005] Electrochemical energy storage devices, such as lithium-ion battery packs, can be used in a variety of products, including automotive products, including start-stop systems (e.g., 12V start-stop systems), battery pack auxiliary systems (“μBAS”), hybrid electric vehicles (“HEVs”), and electric vehicles (“EVs”). A typical lithium-ion battery pack includes two electrodes, a separator, and an electrolyte. Lithium-ion battery packs may also include various terminals and encapsulation materials. In an electrochemical cell (such as in a lithium-ion battery pack), one of the two electrodes serves as the positive electrode or cathode, while the other electrode serves as the negative electrode or anode. Conventional rechargeable lithium-ion battery packs operate by reversibly transferring lithium ions back and forth between the negative and positive electrodes. For example, lithium ions can move from the positive electrode to the negative electrode during battery charging and in the opposite direction during battery discharge.

[0006] A separator and / or electrolyte may be disposed between the negative and positive electrodes. The electrolyte is suitable for conducting lithium ions between the electrodes and, like the two electrodes, can be in solid, liquid, or solid-liquid hybrid form. For example, a solid-state battery pack includes a solid electrolyte disposed between solid electrodes, wherein the solid electrolyte physically separates the electrodes and can serve as both a separator and an ion conductor, thus eliminating the need for a separate separator.

[0007] Lithium-ion battery packs, including those with lithium metal as the anode or cathode, are promising because lithium metal, for example, has a high theoretical specific capacity and a low negative electrochemical potential compared to standard hydrogen electrodes. Furthermore, solid-state battery packs can offer a variety of performance advantages over conventional battery packs using liquid electrolytes, potentially including a wide voltage window and enhanced safety.

[0008] However, lithium metal anodes are susceptible to high reactivity, and unintended reactions between the solid electrolyte and lithium metal, such as side reactions, can lead to shortened battery life and / or reduced cycle time. Furthermore, establishing good contact between the solid electrolyte and solid electrode, such as the lithium metal anode, can be more challenging than in battery packs with liquid electrolytes. Additionally, microscopic and macroscopic void spaces at the interface between solid components can exist or appear over time after cycling, contributing to high interfacial impedance. Therefore, it is desirable to suppress undesirable side reactions while simultaneously improving contact and reducing the interfacial impedance between the lithium metal anode and solid electrolyte in solid-state battery packs. Summary of the Invention

[0009] This section provides a general overview of this disclosure, rather than a full disclosure of its entire scope or all its features.

[0010] This disclosure relates to a composite material interlayer for lithium metal-based solid-state battery packs and a method for preparing the same.

[0011] For example, in some aspects, this disclosure provides a solid-state electrochemical battery for cycling lithium ions. The electrochemical battery may include a solid electrolyte defining a first main surface. The electrochemical battery may also include a negative electrode defining a second main surface. The electrochemical battery may further include an interface layer disposed between the first main surface of the solid electrolyte and the second main surface of the solid electrode. The interface layer may include an ion conductor disposed in an organic matrix.

[0012] In one respect, the negative electrode includes lithium metal.

[0013] In one aspect, ionic conductors include LiNO3, Li3PO4, Li3P, Li2PO2N (LIPON), Li3PS4, Li3ClO, LiF, Li2S, Li3N, ZnO, Al2O3, SnO2, Au, Si, Ge, Mg, Al, In, polyethylene oxide (PEO), polypropylene (PP), 1-butyl-3-methylimidazolium-bis(fluorosulfonyl)imide (BMIM-FSI), particulate graphite, acetylene black, carbon fiber, carbon nanotubes, graphene, or combinations thereof.

[0014] In one respect, ionic conductors include LiNO3, Li3PO4, or both.

[0015] In one respect, solid electrolytes include Li 1+x Al x Ge 2-x (PO4)3 where 0 < x < 1 (LAGP) or Li 1+ x Al x Ti 2-x(PO4)3 where 0 < x < 1 and 0 < y < 2 (LATP), Li x La y TiO3 where 0 < x < 1 and 0 < y < 1 (LLTO), Li 2+2x Zn 1-x GeO4 where 0 < x < 1 (LISICON), Li 10 GeP2S 12 (LGPS), Li 3.25 Ge 0.25 P 0.75 S4, Li4GeS4, Li6PS5Cl, Li7La3Zr2O 12 (LLZO), Li2PO2N (LIPON), or combinations thereof.

[0016] In one respect, solid electrolytes include Li 1+x Al x Ge 2-x (PO4)3, where 0 < x < 1 (LAGP).

[0017] In one respect, the interface layer has a thickness of about 10 nm to about 500 nm.

[0018] In one aspect, the interface layer is formed by a method comprising preparing a mixture comprising an ionic conductor precursor, an organophosphate, and a nonpolar organic solvent. The method may further comprise applying the mixture to a negative electrode. The method may further comprise removing at least a portion of the nonpolar organic solvent from the mixture to form the interface layer. In one aspect, the mixture is applied to the negative electrode for a duration of about one (1) hour. In one aspect, the ionic conductor precursor comprises LiNO3.

[0019] In one aspect, organophosphates include trimethyl phosphate (TMP), triethyl phosphate, tris(1,3-dichloro-2-propyl) phosphate, tris(2-chloroethyl) phosphate, tris(1-chloro-2-propyl) phosphate, tetraethyl pyrophosphate, and tris(2-methylphenyl) phosphate, or combinations thereof.

[0020] In one respect, nonpolar organic solvents include diethyl ether, 1,2-dimethoxyethane, 1,4-dioxane, tetraethylene glycol dimethyl ether (TEGDME), carbon tetrachloride, benzene, hexane, dichloromethane, or combinations thereof.

[0021] Alternatively or concurrently, in some aspects, this disclosure provides a method for manufacturing a solid-state electrochemical battery capable of cycling lithium-ion batteries. The method may include preparing a mixture comprising an ionic conductor precursor, an organophosphate ester, and a nonpolar organic solvent. The method may further include applying the mixture to a negative electrode. The method may also include removing at least a portion of the nonpolar organic solvent from the mixture to form a coating.

[0022] In one aspect, the method may further include positioning a negative electrode adjacent to a solid electrolyte, such that a coating is disposed between the negative electrode and the solid electrolyte, and pressing the negative electrode and the solid electrolyte together such that the coating forms an interface layer. In one aspect, the interface layer is disposed between a first main surface of the solid electrolyte and a second main surface of the solid electrode, wherein the interface layer includes an ionic conductor disposed in an organic matrix. In one aspect, the negative electrode comprises lithium metal, and the ionic conductor comprises LiNO3, Li3PO4, Li3P, Li2PO2N (LIPON), Li3PS4, Li3ClO, LiF, Li2S, Li3N, ZnO, Al2O3, SnO2, Au, Si, Ge, Mg, Al, In, polyethylene oxide (PEO), polypropylene (PP), 1-butyl-3-methylimidazolium-bis(fluorosulfonyl)imide (BMIM-FSI), particulate graphite, acetylene black, carbon fiber, carbon nanotubes, graphene, or combinations thereof.

[0023] In one respect, the mixture is applied to the negative electrode for a duration of about one (1) hour.

[0024] In one respect, ionic conductor precursors include LiNO3.

[0025] In one aspect, organophosphates include trimethyl phosphate (TMP), triethyl phosphate, tris(1,3-dichloro-2-propyl) phosphate, tris(2-chloroethyl) phosphate, tris(1-chloro-2-propyl) phosphate, tetraethyl pyrophosphate, and tris(2-methylphenyl) phosphate, or combinations thereof.

[0026] In one respect, nonpolar organic solvents include diethyl ether, 1,2-dimethoxyethane, 1,4-dioxane, tetraethylene glycol dimethyl ether (TEGDME), carbon tetrachloride, benzene, hexane, dichloromethane, or combinations thereof.

[0027] The present invention discloses the following embodiments:

[0028] Implementation Scheme 1. A solid-state electrochemical battery for cycling lithium ions, the electrochemical battery comprising:

[0029] A solid electrolyte that defines the first primary surface;

[0030] The negative electrode is defined on the second main surface; and

[0031] An interface layer is disposed between the first main surface of the solid electrolyte and the second main surface of the solid electrode, wherein the interface layer includes an ion conductor disposed in an organic matrix.

[0032] Implementation Scheme 2. The solid-state electrochemical battery according to Implementation Scheme 1, wherein the negative electrode comprises lithium metal.

[0033] Implementation Scheme 3. The solid-state electrochemical battery according to Implementation Scheme 1, wherein the ion conductor includes LiNO3, Li3PO4, Li3P, Li2PO2N (LIPON), Li3PS4, Li3ClO, LiF, Li2S, Li3N, ZnO, Al2O3, SnO2, Au, Si, Ge, Mg, Al, In, polyethylene oxide (PEO), polypropylene (PP), 1-butyl-3-methylimidazolium-bis(fluorosulfonyl)imide (BMIM-FSI), particulate graphite, acetylene black, carbon fiber, carbon nanotubes, graphene, or combinations thereof.

[0034] Implementation Scheme 4. The solid-state electrochemical battery according to Implementation Scheme 1, wherein the ion conductor includes LiNO3, Li3PO4, or both.

[0035] Implementation Scheme 5. The solid-state electrochemical battery according to Implementation Scheme 1, wherein the solid electrolyte comprises Li 1+x Al x Ge 2-x (PO4)3 where 0 < x < 1 (LAGP) or Li 1+x Al x Ti 2-x (PO4)3 where 0 < x < 1 and 0 < y < 2 (LATP), Li x La y TiO3 where 0 < x < 1 and 0 < y < 1 (LLTO), Li 2+2x Zn 1-x GeO4 where 0 < x < 1 (LISICON), Li 10 GeP2S 12 (LGPS), Li 3.25 Ge 0.25 P 0.75 S4, Li4GeS4, Li6PS5Cl, Li7La3Zr2O 12 (LLZO), Li2PO2N (LIPON), or combinations thereof.

[0036] Implementation Scheme 6. The solid-state electrochemical battery according to Implementation Scheme 1, wherein the solid-state electrolyte comprises Li 1+x Al x Ge 2-x(PO4)3 where 0 < x < 1 (LAGP).

[0037] Implementation Scheme 7. The solid-state electrochemical cell according to Implementation Scheme 1, wherein the interface layer has a thickness of more than or equal to about 10 nm to less than or equal to about 500 nm.

[0038] Implementation Scheme 8. The solid-state electrochemical battery according to Implementation Scheme 1, wherein the interface layer is formed by a method comprising:

[0039] Prepare a mixture comprising an ionic conductor precursor, an organophosphate ester, and a nonpolar organic solvent;

[0040] The mixture is applied to the negative electrode; and

[0041] At least a portion of the nonpolar organic solvent is removed from the mixture to form an interface layer.

[0042] Implementation Scheme 9. The solid-state electrochemical battery according to Implementation Scheme 8, wherein the mixture is applied to the negative electrode for a duration of about five (5) minutes to about ten (10) hours.

[0043] Implementation Scheme 10. The solid-state electrochemical battery according to Implementation Scheme 8, wherein the ionic conductor precursor comprises LiNO3.

[0044] Implementation Scheme 11. The solid-state electrochemical battery according to Implementation Scheme 8, wherein the organophosphate includes trimethyl phosphate (TMP), triethyl phosphate, tris(1,3-dichloro-2-propyl) phosphate, tris(2-chloroethyl) phosphate, tris(1-chloro-2-propyl) phosphate, tetraethyl pyrophosphate and tris(2-methylphenyl) phosphate, or combinations thereof.

[0045] Implementation Scheme 12. The solid-state electrochemical battery according to Implementation Scheme 8, wherein the nonpolar organic solvent includes diethyl ether, 1,2-dimethoxyethane, 1,4-dioxane, tetraethylene glycol dimethyl ether (TEGDME), carbon tetrachloride, benzene, hexane, dichloromethane, or combinations thereof.

[0046] Implementation Scheme 13. A method for manufacturing a solid-state electrochemical battery for cycling lithium ions, the method comprising:

[0047] Prepare a mixture comprising an ionic conductor precursor, an organophosphate ester, and a nonpolar organic solvent;

[0048] The mixture is applied to the negative electrode; and

[0049] At least a portion of the nonpolar organic solvent is removed from the mixture to form a coating.

[0050] Implementation Scheme 14. The method according to Implementation Scheme 13 further includes:

[0051] The negative electrode is positioned adjacent to the solid electrolyte, such that the coating is disposed between the negative electrode and the solid electrolyte; and

[0052] The negative electrode and the solid electrolyte are pressed together, so that the coating forms an interface layer.

[0053] Implementation Scheme 15. The method according to Implementation Scheme 14, wherein the interface layer is disposed between the first main surface of the solid electrolyte and the second main surface of the solid electrode, wherein the interface layer includes an ion conductor disposed in an organic matrix.

[0054] Implementation Scheme 16. The method described in Implementation Scheme 14,

[0055] The negative electrode contains lithium metal, and

[0056] The ionic conductors mentioned above include LiNO3, Li3PO4, Li3P, Li2PO2N (LIPON), Li3PS4, Li3ClO, LiF, Li2S, Li3N, ZnO, Al2O3, SnO2, Au, Si, Ge, Mg, Al, In, polyethylene oxide (PEO), polypropylene (PP), 1-butyl-3-methylimidazolium-bis(fluorosulfonyl)imide (BMIM-FSI), particulate graphite, acetylene black, carbon fiber, carbon nanotubes, graphene, or combinations thereof.

[0057] Implementation Scheme 17. The method according to Implementation Scheme 13, wherein the mixture is applied to the negative electrode for a duration of about one (1) hour.

[0058] Implementation Scheme 18. The method according to Implementation Scheme 13, wherein the ionic conductor precursor comprises LiNO3.

[0059] Implementation Scheme 19. The method according to Implementation Scheme 13, wherein the organophosphate comprises trimethyl phosphate (TMP), triethyl phosphate, tris(1,3-dichloro-2-propyl) phosphate, tris(2-chloroethyl) phosphate, tris(1-chloro-2-propyl) phosphate, tetraethyl pyrophosphate and tris(2-methylphenyl) phosphate, or combinations thereof.

[0060] Implementation Scheme 20. The method according to Implementation Scheme 13, wherein the nonpolar organic solvent comprises diethyl ether, 1,2-dimethoxyethane, 1,4-dioxane, tetraethylene glycol dimethyl ether (TEGDME), carbon tetrachloride, benzene, hexane, dichloromethane, or combinations thereof.

[0061] Further applications will become apparent from the description provided herein. The descriptions and specific examples in this invention are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0062] The accompanying drawings described herein are for illustrative purposes only, and not for all possible implementations, and are not intended to limit the scope of this disclosure.

[0063] Figure 1 This is an illustration of an example of a solid-state battery pack.

[0064] Figure 2 This is a graphical illustration of electrochemical impedance spectroscopy (EIS) data of a first electrochemical cell containing lithium metal, which was immersed in a mixture for one hour and formed according to the following disclosure.

[0065] Figure 3 This is a graphic illustration of EIS data for a second electrochemical cell containing lithium metal, which was immersed in a mixture for two hours and formed according to the following disclosure.

[0066] Figure 4 This is a graphical illustration of the EIS data for a reference electrochemical cell.

[0067] Figure 5 This is a graphical illustration of the cycle data of a first electrochemical cell containing lithium metal, which is immersed in a mixture for one hour and formed according to the following disclosure.

[0068] Figure 6 This is a graphical illustration of the cycle data of a second electrochemical cell containing lithium metal, which is immersed in a mixture for two hours and formed according to the following disclosure.

[0069] Figure 7 This is a graphical illustration of the cycle data for a reference electrochemical cell.

[0070] In the various views of the accompanying drawings, the corresponding reference numerals denote the respective components. Detailed Implementation

[0071] Exemplary embodiments are provided to make this disclosure complete and to fully communicate its scope to those skilled in the art. Numerous specific details, such as examples of specific components, parts, apparatuses, and methods, are set forth to provide a full understanding of embodiments of this disclosure. It will be apparent to those skilled in the art that specific details are not required, that exemplary embodiments may be presented in many different forms, and that none of them should be construed as limiting the scope of this disclosure. In some exemplary embodiments, well-known methods, well-known apparatus structures, and well-known techniques are not described in detail.

[0072] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include the plural forms as used herein. The terms “comprising,” “including,” “covering,” and “having” are concurrent and thus specify the presence of the stated features, elements, compositions, steps, integers, operations, and / or components, but do not exclude the presence or inclusion of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Although the open-ended term “comprising” should be understood as a non-limiting term used to describe and claim the various embodiments described herein, in some respects it may be understood alternatively to more restrictive and limiting terms such as “consisting of” or “substantially consisting of.” Thus, for any given embodiment recounting a composition, material, component, element, feature, integer, operation, and / or method step, this disclosure also specifically includes embodiments consisting of or substantially consisting of such recounted compositions, materials, components, elements, features, integers, operations, and / or method steps. In the case of “consisting of…”, the alternative embodiments exclude any additional compositions, materials, components, elements, features, integers, operating and / or method steps. In the case of “essentially composed of…”, any additional compositions, materials, components, elements, features, integers, operating and / or method steps that substantially affect the essential and novel characteristics are excluded from such embodiments. However, any compositions, materials, components, elements, features, integers, operating and / or method steps that do not substantially affect the essential and novel characteristics may be included in the embodiments.

[0073] Any methods, procedures, and operations described herein should not be construed as necessarily requiring them to be performed in the specific order discussed or illustrated, unless explicitly stated as such. It should also be understood that, unless otherwise stated, additional or alternative steps may be employed.

[0074] When a component, element, or layer is mentioned as being “on,” “engaged,” “connected,” or “coupled” to another component or layer, it may be directly engaged, connected, or coupled to the other component, element, or layer, or an intermediary element or layer may be present. Conversely, when an element is mentioned as being “directly on,” “directly engaged,” “directly connected,” or “directly coupled” to another component or layer, an intermediary element or layer may not be present. Other terms used to describe relationships between elements should be interpreted similarly (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and / or” includes any and all combinations of one or more of the related enumerations.

[0075] Although the terms first, second, third, etc., may be used herein to describe various steps, elements, components, regions, layers, and / or sections, these steps, elements, components, regions, layers, and / or sections should not be limited by these terms unless otherwise stated. These terms may be used only to distinguish one step, element, component, region, layer, or section from another. Unless the context clearly indicates otherwise, terms such as “first,” “second,” and other numerical terms used herein do not imply order or sequence. Therefore, the first step, element, component, region, layer, or section discussed below may be referred to as the second step, element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0076] For ease of description, spatially or temporally relative terms such as “before,” “after,” “inner,” “outer,” “below,” “below,” “lower,” “above,” “upper,” etc., may be used herein to describe the relationship of one element or feature as shown in the accompanying drawings to other elements or features(s). In addition to the orientations shown in the accompanying drawings, spatially or temporally relative terms may be intended to cover different orientations of the apparatus or system during use or operation.

[0077] Throughout this disclosure, numerical values ​​represent approximate measurements or range limits to cover slight deviations from a given value and embodiments that substantially have the mentioned value as well as embodiments that precisely have the mentioned value. Except in the detailed description of the working examples provided at the end, all numerical values ​​of parameters (e.g., quantities or conditions) in this specification (including the appended claims) should be understood to be modified in all cases by the term “about,” regardless of whether “about” actually precedes the numerical value. “About” means that the numerical value allows for a certain degree of slight imprecision (approaching the exact value to a certain extent; substantially or reasonably approximating the value; almost). If the imprecision provided by “about” is not otherwise understood in this ordinary sense in the art, then “about” as used herein refers to at least a deviation that can be caused by ordinary methods of measuring and using such parameters. For example, “about” may include deviations of less than or equal to 5%, optionally less than or equal to 4%, optionally less than or equal to 3%, optionally less than or equal to 2%, optionally less than or equal to 1%, optionally less than or equal to 0.5%, and in some respects optionally less than or equal to 0.1%.

[0078] In addition, the disclosure of the range includes disclosure of all values ​​throughout the range and disclosure of further subdivisions of the range, including disclosure of endpoints and subranges given by the range.

[0079] Exemplary embodiments will now be described more fully with reference to the accompanying drawings.

[0080] As mentioned above, lithium-ion battery packs including anodes or anodes containing lithium metal are promising because lithium metal has a high theoretical specific capacity of approximately 3,860 mAh / g and a specific capacity of approximately 0.53 g / cm³ compared to standard hydrogen electrodes. 3 The lithium metal anode exhibits low density and a low negative electrochemical potential of approximately -3.04 V. However, lithium metal anodes are susceptible to high reactivity, such as unintended side reactions between lithium metal and the solid electrolyte, potentially leading to shortened battery life and / or reduced cycle time. Furthermore, large volume changes can result in dendrite growth, mossy structures, and low cycle efficiency. Additionally, as mentioned above, solid-state battery packs incorporating solid electrodes such as lithium anodes can exhibit high interfacial impedance due to poor contact between solid lithium and solid electrolyte materials.

[0081] In various aspects, this disclosure provides an electrochemical cell including an interface layer disposed between a solid electrode, such as a lithium electrode, and a solid electrolyte. This disclosure also provides a method for forming an electrochemical cell having the interface layer. In various aspects, the interface layer effectively suppresses unintended side reactions between lithium metal and the solid electrolyte and reduces the interfacial impedance between the solid electrode and the solid electrolyte.

[0082] Figure 1 An exemplary and schematic illustration of an electrochemical battery 20 (also referred to herein as a “battery pack”) for cycling lithium ions is shown. It is important to note that the components shown in the electrochemical battery pack 20 are not to scale. Unless otherwise specifically stated, the term “ion” as used herein refers to lithium ions, but alternatively may refer to other ions, such as sodium ions. The battery pack 20 includes a negative electrode 22, a positive electrode 24, a solid electrolyte 26 disposed between the negative electrode 22 and the positive electrode 24, and an interface layer 28 disposed between the negative electrode 22 and the solid electrolyte. The solid electrolyte 26 is both a separator physically separating the negative electrode 22 from the positive electrode 24 and an ion-conducting electrolyte. The solid electrolyte 26 may be defined by a plurality of solid electrolyte particles 30. A negative current collector 32 may be located at or near the negative electrode 22, and a positive current collector 34 may be located at or near the positive electrode 24. The negative current collector 32 and the positive current collector 34 collect and move free electrons to and from an external circuit 40, respectively (as indicated by the box arrows). For example, the interruptible external circuit 40 and the load device 42 can be connected to the negative electrode 22 (through the negative electrode current collector 32) and the positive electrode 24 (through the positive electrode current collector 34). As shown, the negative electrode 22 can be a solid film containing electroactive material, while the positive electrode 24 can be a composite electrode containing multiple electroactive material particles 36 and (either) solid electrolyte particles 44 and optionally multiple conductive particles 38.

[0083] During discharge, battery pack 20 generates current via a reversible electrochemical reaction (as indicated by the box arrows) that occurs when external circuit 40 is closed (connecting negative electrode 22 and positive electrode 24) and negative electrode 22 contains a relatively large amount of lithium. The chemical potential difference between negative electrode 22 and positive electrode 24 drives electrons generated by the oxidation of lithium inserted at negative electrode 22 through external circuit 40 to positive electrode 24. Ions also generated at negative electrode 22 are simultaneously transferred to positive electrode 24 via solid electrolyte 26. Electrons flow through external circuit 40 and ions migrate through solid electrolyte 26 to positive electrode 24, where they can be deposited, reacted, or intercalated. The current flowing through external circuit 40 can be utilized and directed through load device 42 (in the direction of the box arrows) until the lithium in negative electrode 22 is depleted and the capacity of battery pack 20 decreases.

[0084] By connecting an external power source (e.g., a charging device) to the battery pack 20 to reverse the electrochemical reactions that occur during battery pack discharge, the battery pack 20 can be charged or recharged at any time. The connection of the external power source to the battery pack 20 forces the non-spontaneous oxidation of one or more metal elements at the positive electrode 24 to generate electrons and ions. Electrons flowing back to the negative electrode 22 through the external circuit 40 and ions moving through the solid electrolyte 26 back to the negative electrode 22 recombine at the negative electrode 22, replenishing the lithium consumed during the next battery pack discharge cycle. Thus, each discharge and charge event is considered a cycle in which ions circulate between the positive electrode 24 and the negative electrode 22.

[0085] The external power source that can be used to charge the battery pack 20 may vary depending on the size, construction, and specific end use of the battery pack 20. Some notable and exemplary external power sources include, but are not limited to, AC power sources, such as AC wall sockets and vehicle alternators. In many configurations of the battery pack 20, each of the negative current collector 32, negative electrode 22, solid electrolyte 26, positive electrode 24, and positive current collector 34 is fabricated as a relatively thin layer (e.g., with a thickness from a few micrometers to millimeters or less) and assembled in parallel arrangement to provide suitable electrical energy and power encapsulation. In various other cases, the battery pack 20 may include electrodes 22, 24 connected in series.

[0086] In addition, in some respects, battery pack 20 may include a variety of other components, although not described herein, but which are known to those skilled in the art. For example, by way of non-limiting example, battery pack 20 may include a housing, gaskets, terminal covers, and any other conventional components or materials that may be located within or around the negative electrode 22, positive electrode 24, and / or solid electrolyte 26. As mentioned above, the size and shape of battery pack 20 may vary depending on the specific application it is designed for. Battery-powered vehicles and handheld consumer electronics are two examples in which battery pack 20 will likely be designed with different sizes, capacities, and power output specifications. If required by load device 42, battery pack 20 may also be connected in series or parallel with other similar lithium-ion batteries or battery packs to produce greater voltage output, energy, and power.

[0087] Therefore, the battery pack 20 can generate current to a load device 42, which can be operatively connected to an external circuit 40. When the battery pack 20 discharges, the load device 42 can be powered entirely or partially by the current flowing through the external circuit 40. While the load device 42 can be any number of known electrical devices, specific examples of power-consuming load devices, by way of non-limiting example, include electric motors for hybrid or all-electric vehicles, laptop computers, tablet computers, cellular phones, and cordless power tools or appliances. The load device 42 can also be a generator that charges the battery pack 20 for the purpose of storing energy.

[0088] Further reference Figure 1 The solid electrolyte 26 provides electrical isolation, preventing physical contact between the negative electrode 22 (anode) and the positive electrode 24 (cathode). The solid electrolyte 26 also provides a minimal resistance path for the internal passage of ions. In various aspects, as described above, a plurality of solid electrolyte particles 30 may define the solid electrolyte 26. In some aspects, the solid electrolyte particles 30 comprise NASICON-type superionic conductive glass-ceramics, such as Li. 1+x Al x Ge 2-x (PO4)3(LAGP) or Li 1+x Al x Ti 2-x (PO4)3, where 0 < x < 1 and 0 < y < 2 (LATP), perovskites such as Li x La y TiO3, where 0 < x < 1 and 0 < y < 1 (LLTO); Li 2+2x Zn 1-x GeO4, where 0 < x < 1 (LISICON); sulfide ceramics / glasses: Li 10 GeP2S 12(LGPS), Li 3.25 Ge 0.25 P 0.75 S4, Li4GeS4 and Li6PS5Cl; ceramic oxides, such as garnet-type Li a La b Zr c O d Materials, such as Li7La3Zr2O 12 (LLZO); Li₂PO₂N (LIPON) and combinations thereof are provided as non-limiting examples. In some embodiments, the solid electrolyte particles 30 optionally contain dopants. The solid electrolyte material may be selected to be stable in the presence of certain electroactive materials such as lithium.

[0089] The solid electrolyte 26 may be in the form of a layer or composite material comprising a first plurality of solid electrolyte particles 30. For example, the solid electrolyte 26 may be in the form of a layer having a thickness greater than or equal to about 1 μm and less than or equal to about 1 mm, and in some aspects optionally greater than or equal to about 1 μm and less than or equal to about 100 μm. Such a solid electrolyte 26 may have an interparticle porosity of less than or equal to about 10% by volume, optionally less than or equal to about 5% by volume, after being processed into a solidified form or final state.

[0090] The negative electrode 22 may be formed from a lithium host material capable of serving as the negative terminal for lithium ions. In some aspects, the negative electrode 22 may be a layer, for example, a solid film comprising lithium metal. In some variations, the negative electrode 22 may comprise elemental lithium or a lithium alloy. In other variations, the negatively active material forming the negative electrode 22 may comprise a silicon-based material, such as a silicon alloy. In still other variations, the negative electrode 22 may comprise a carbon-containing material, such as graphite or graphene. In yet another variation, the negative electrode 22 may comprise one or more negatively active materials, such as lithium titanium oxide (Li4Ti5O4). 12 ) and sodium titanium oxide (Na4Ti5O) 12 (); one or more metal oxides, such as V₂O₅; and metal sulfides, such as FeS. In Figure 1 In an alternative aspect not shown, the negative electrode 22 may be a composite electrode having a plurality of negatively active material particles distributed within a matrix having an electrolyte and optional conductive particles, as will be described in the context of the positive electrode 24.

[0091] The negative current collector 32 may be formed of copper (Cu), stainless steel or any other conductive material known to those skilled in the art.

[0092] In the case of lithium-ion battery packs, lithium is intercalated into the electrode active material and / or forms an alloy within the electrode active material. In the case of lithium metal battery packs, there is no intercalation or alloying; lithium dissolves from the negative electrode and migrates to the positive electrode. At the positive electrode, lithium reacts / plats during discharge and is plated onto the negative electrode during charging.

[0093] Therefore, the positive electrode 24 can be formed of a lithium-based electroactive material that can undergo lithium cycling (e.g., plating and stripping) and simultaneously serve as the positive terminal of the battery pack 20. For example, but not limited to, in some variations, the positive electrode 24 can be defined by a plurality of positive solid-state electroactive particles 36. However, it should be noted that the positive electrode 24 is not limited to... Figure 1 The embodiments shown are available and can take many forms, including solid electrodes, semi-solid electrodes, gas electrodes, or liquid electrodes.

[0094] In some cases, for example, such as Figure 1 As shown, the positive electrode 24 is a composite material comprising a mixture of positive solid electroactive particles 36 and solid electrolyte particles 44. For example, the positive electrode 24 may comprise greater than or equal to about 10% by weight and less than or equal to about 95% by weight, and in some aspects optionally greater than or equal to about 50% by weight and less than or equal to about 90% by weight of positive solid electroactive particles 36 and greater than or equal to about 5% by weight and less than or equal to about 70% by weight, and in some aspects optionally greater than or equal to about 10% by weight and less than or equal to about 30% by weight of a plurality of solid electrolyte particles 44. The positive electrode 24 may have an interparticle porosity of less than or equal to about 20% by volume, optionally less than or equal to about 10% by volume, between the positive solid electroactive particles 36 and / or the solid electrolyte particles 44. In some variations, the plurality of solid electrolyte particles 44 may be the same as or different from the solid electrolyte particles 30 in the separator 26 in terms of composition, size, or combination thereof.

[0095] The positive electrode 24 may comprise any suitable positively active material capable of cycling lithium. In various aspects, the positive electrode 24 may be formed of a positively active material 36, which is one of a layered oxide cathode, a spinel cathode, or a polyanionic cathode. For example, in the case of a layered oxide cathode (e.g., rock salt layered oxide), the positively active solid particles 36 may comprise one or more positively active materials selected from: LiCoO2, LiNi x Mn y Co 1-x-y O2 (where 0 ≤ x ≤ 1 and 0 ≤ y ≤ 1), LiNi x Mn 1-x O2 (where 0 ≤ x ≤ 1), and Li 1+x MO2 (where 0 ≤ x ≤ 1). Spinel cathodes may include one or more positively charged active materials, such as LiMn2O4 and LiNi.x Mn 1.5 O4. The polyanion cathode may include, for example, phosphates such as LiFePO4, LiVPO4, LiV2(PO4)3, Li2FePO4F, Li3Fe3(PO4)4, or Li3V2(PO4)F3 and / or silicates such as LiFeSiO4. In various aspects, the positive solid chemically active particles 36 may include one or more positively charged active materials selected from LiCoO2, LiNi... x Mn y Co 1-x-y O2 (where 0 ≤ x ≤ 1 and 0 ≤ y ≤ 1), LiNi x Mn 1-x O2 (where 0 ≤ x ≤ 1), Li 1+x MO2 (where 0 ≤ x ≤ 1), LiMn2O4, LiNi x Mn 1.5 O4, LiFePO4, LiVPO4, LiV2(PO4)3, Li2FePO4F, Li3Fe3(PO4)4, Li3V2(PO4)F3, LiFeSiO4, and combinations thereof. In other respects, additional materials suitable for providing a desired voltage between the positive electrode 24 and the negative electrode 22 may be used.

[0096] In some variations, particles 36 may optionally be mixed with one or more conductive materials 38 that provide an electronic conduction path and / or at least one polymeric binder material (not shown) that improves the structural integrity of the positive electrode 24. The conductive material 38 may include, for example, carbon-based materials, powdered nickel or other metal particles, or conductive polymers. Carbon-based materials may include, for example, graphite, acetylene black (e.g., KETCHEN). TM Black or Denka TM Particles such as black carbon fibers and nanotubes, graphene, etc. Examples of conductive polymers may include polyaniline, polythiophene, polyacetylene, polypyrrole, etc. In some aspects, mixtures of conductive materials may be used. The positive solid-state electroactive particles 36 may optionally be mixed with binders such as polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene propylene diene monomer (EPDM), nitrile butadiene rubber (NBR), styrene-butadiene rubber (SBR), lithium polyacrylate (LiPAA), and / or sodium polyacrylate (NaPAA) binders.

[0097] The positive electrode 24 may contain one or more conductive materials 38, which may be greater than or equal to about 0% by weight and less than or equal to about 25% by weight, optionally greater than or equal to about 0% by weight and less than or equal to about 10% by weight, and in some aspects, optionally greater than or equal to about 0% by weight and less than or equal to about 5% by weight, and one or more adhesives, which may be greater than or equal to about 0% by weight and less than or equal to about 20% by weight, optionally greater than or equal to about 0% by weight and less than or equal to about 10% by weight, and in some aspects, optionally greater than or equal to about 0% by weight and less than or equal to about 5% by weight.

[0098] The positive current collector 34 may be formed of aluminum (Al) or any other conductive material known to those skilled in the art.

[0099] Refer again Figure 1 The interface layer 28 can be disposed between the negative electrode 22 and the solid electrolyte 26. For example, as... Figure 1 As shown, the negative electrode 22 may include a second main surface 23 that generally faces the solid electrolyte 26, and the solid electrolyte 26 may include a first main surface 27 that generally faces the negative electrode.

[0100] The interface layer 28 may include a composite material. For example, in some aspects, the composite material includes one or more ionic conductors disposed within an organic matrix.

[0101] In various aspects, one or more ionic conductors may comprise ionicly conductive and electrochemically stable components relative to lithium metal, such as compounds. For example, in some aspects, one or more ionic conductors may be effective and enable interface layer 28 to exhibit ionic conductivity. Without wishing to be bound by theory, interface layer 28 may effectively provide an ion migration path between the negative electrode 22 and the solid electrolyte 26, for example, at the interface between the negative electrode 22 and the solid electrolyte 26.

[0102] In various respects, examples of ionic conductors can include LiNO3; Li3PO4; phosphorus-containing compounds such as Li3P, Li2PO2N (LIPON), and Li3PS4; halogen-containing compounds such as Li3ClO and LiF; sulfur-containing compounds such as Li2S; nitrogen-containing compounds such as Li3N; oxides such as ZnO, Al2O3, and SnO2; metals such as Au, Si, Ge, Mg, Al, and In; polymers such as polyethylene oxide (PEO) and polypropylene (PP); ionic liquids such as 1-butyl-3-methylimidazolium-bis(fluorosulfonyl)imide (BMIM-FSI); and carbon-based materials such as particulate graphite and acetylene black (e.g., KETCHEN). TM Black or Denka TM Black), carbon fiber and nanotubes, graphene, etc.

[0103] In some respects, the organic matrix may include one or more suitable organic substances. For example, and as will be discussed, the organic matrix may include various organic substances produced by the in-situ formation of ionic conductors, for example, when the interface layer 28 is formed according to the methods described herein.

[0104] Additionally, in some aspects, the organic matrix can effectively provide the interface layer with physical structure and / or rigidity. Additionally or optionally, in various aspects, the organic matrix can effectively stabilize the composition of the interface layer 28, for example, by retaining ionic conductors within the interface layer 28. In various embodiments, the interface layer 28 is characterized by having a thickness greater than or equal to about 10 nm to less than or equal to about 500 nm.

[0105] Additionally, in some aspects, battery packs are formed, for example regarding... Figure 1 The method for the battery pack 20 discussed may include preparing a mixture comprising an ionic conductor precursor, an organophosphate ester, and a nonpolar organic solvent. Examples of ionic conductor precursors include, but are not limited to, LiNO3. Examples of organophosphate esters include trimethyl phosphate (TMP), triethyl phosphate, tris(1,3-dichloro-2-propyl) phosphate, tris(2-chloroethyl) phosphate, tris(1-chloro-2-propyl) phosphate, tetraethyl pyrophosphate, tris(2-methylphenyl) phosphate, etc. Examples of nonpolar organic solvents include, but are not limited to, diethyl ether, 1,2-dimethoxyethane, 1,4-dioxane, tetraethylene glycol dimethyl ether (TEGDME), carbon tetrachloride, benzene, hexane, or dichloromethane.

[0106] In various aspects, the ionic conductor precursor may be present in the mixture in an amount of about 1% to about 50% by weight, or about 5% to about 40% by weight. Furthermore, in various aspects, the organophosphate ester may be present in the mixture in an amount of about 1% to about 99% by weight, or about 25% to about 75% by weight. Furthermore, in various aspects, the solvent may be present in the mixture in an amount of about 1% to about 99% by weight, or about 25% to about 75% by weight. Without intending to be bound by theory, in some aspects the amount of solvent may be adjusted to achieve one or more desired parameters, such as viscosity.

[0107] Additionally, in some aspects, the method of forming the battery pack may also include applying a mixture to the negative electrode 22, such as lithium metal applied to the negative electrode 22. In various aspects, the mixture may be applied to the negative electrode 22 by any suitable application method, examples of which may include, but are not limited to, dip coating, spin coating, layer-by-layer (LBL) coating, or spray coating. Typically, for example, the mixture may be applied to the negative electrode 22 in an amount sufficient to give the interface layer 28 a desired parameter or combination of parameters, such as a desired thickness, by means of a single applicable application or multiple sequential applications. In various aspects, the duration for which the mixture may be applied to the negative electrode may vary, for example, from about (5) minutes to about 24 hours, or from about five (5) minutes to about 10 hours, or from about 15 minutes to about 12 hours, or from about 30 minutes to about ten (10) hours, or from about one (1) hour to about five (5) hours, or from about one (1) hour to about two (2) hours, or about one (1) hour, or about two (2) hours.

[0108] Furthermore, in some aspects, the method of forming the battery pack may also include, after applying the mixture to the negative electrode 22, allowing and / or causing at least a portion of the nonpolar organic solvent to be removed from the mixture, for example, to form a coating on the surface of the negative electrode 22 (e.g., the second main surface 23). For example, the mixture may be dried in situ. In some aspects, the mixture may be dried at room temperature, or additionally or alternatively, in a heated environment, in a negative pressure environment, in an inert environment, or under other conditions suitable for achieving at least a portion of the removal of the nonpolar organic solvent from the mixture.

[0109] In some aspects, applying the mixture to the negative electrode 22 and removing (e.g., dissipating and / or evaporating) the nonpolar organic solvent from the mixture in situ can lead to a chemical reaction between at least a portion of the ionic conductor precursor and at least a portion of the organophosphate. In one example, the ionic conductor precursor comprises LiNO3, and at least a portion of the organophosphate comprises trimethyl phosphate. In this example, a portion of LiNO3 reacts with a portion of trimethyl phosphate to form Li3PO4. In this example, the interface layer 28 may comprise LiNO3 and Li3PO4 disposed (e.g., embedded) within an organic matrix, which may comprise one or more organic substances generated by the reaction between trimethyl phosphate and LiNO3 to form Li3PO4.

[0110] In some aspects, after the mixture is applied to the negative electrode 22, and after a desired duration has elapsed and the desired portion of the nonpolar solvent has been removed (e.g., the mixture has been allowed to dry), the negative electrode 22 may be disposed relative to the solid electrolyte 26 (e.g., adjacent), such that a coating disposed on the negative electrode 22 forms a layer (e.g., interface layer 28) between the negative electrode 22 and the solid electrolyte 26. Similarly, the positive electrode 24 may be disposed relative to the solid electrolyte 26 (e.g., adjacent). For example, in some aspects, the layers of the electrochemical cell may be pressed together. For example, a pressure of 0 MPa to about 500 MPa may be applied to press the layers of the electrochemical cell together.

[0111] In some aspects, methods for forming battery packs, as discussed herein, may include one or more additional post-processing steps. For example, electrodes and / or batteries formed according to these methods may undergo additional processing to move the electrodes and / or batteries toward an intermediate or final product, for example, referring to Figure 1 The battery pack 20 under discussion. For example, in some aspects, one or more tabs may be attached to one or more of the electrodes. For example, the negative tab may be attached (e.g., welded) to the negative current collector 32, and the positive tab may be attached (e.g., welded) to the positive current collector 34. Furthermore, in some aspects, the battery may also be sealed, for example by placing it in an aluminum laminated bag or container and / or by vacuum sealing.

[0112] In some respects, the battery pack formed according to the method discussed herein includes, for example, an interface layer 28. Figure 1 The battery pack 20 can exhibit improved performance, including improved battery pack life and / or improved cycle performance.

[0113] For example, in some respects, the interface layer 28 can effectively suppress side reactions that may occur between the negative electrode 22 or a portion thereof (e.g., lithium metal) and the solid electrolyte 26 (e.g., solid electrolyte particles 30). In the absence of such... Figure 1 When the interface layer 28 is formed, one or more side reactions between one or more components of the solid electrolyte 26 and lithium present at the negative electrode 22 can lead to the growth of an electronically conductive interface with reduced ionic conductivity, which can also lead to increased interface resistance and / or impedance, volume changes, and potential cracking of the solid electrolyte 26. These undesirable effects result in shortened battery life, reduced cycle capability, and overall performance degradation. Examples of such undesirable side reactions may include the reduction of germanium present within the LAGP and / or the diffusion of aluminum between the LAGP and lithium metal. In some aspects, side reactions suppressed by the interface layer 28 may include the reduction and / or diffusion of one or more substances present within the solid electrolyte particles, such as the reduction of germanium present within the LAGP and / or the diffusion of aluminum between the LAGP and lithium metal.

[0114] Alternatively, in some respects, interface layer 28 can effectively improve various properties related to interface impedance, such as at the interface between the negative electrode 22 and the solid electrolyte 26. For example, without being bound by theory, interface layer 28 can provide a path for ion conduction between the negative electrode 22 and the solid electrolyte 26. For example, ion conductors present within interface layer 28 can effectively provide an improved path for ion conduction through interface layer 28.

[0115] Alternatively or alternatively, and not intended to be theoretically constrained, the interface layer 28 may also effectively fill the void space at or near the interface between the negative electrode 22 and the solid electrolyte 26 (e.g., between the second main surface 23 and the first main surface 27). For example, interparticle porosity and / or voids between various particles defined within the battery pack 20 (e.g., between the particles of the solid electrolyte 26) can reduce contact and / or conduction, which can lead to higher interfacial impedance and reduced battery pack performance. In various aspects, the contact between the solid electrolyte 26 and the negative electrode 22 (e.g., lithium metal present at or above the negative electrode 22) can be improved by the interface layer 28, which can at least partially fill a portion of the interparticle space at or near the interface between the negative electrode 22 and the solid electrolyte 26. For example, the interface layer 28 may be at least partially disposed within the interparticle space to wet the interface and / or fill the void space between the particles of the solid electrolyte 26 and the negative electrode 22. Example

[0116] Test cells were prepared to demonstrate the properties of the electrochemical cells prepared according to certain aspects of this disclosure. To prepare the test cells, a mixture comprising 1,2-dimethoxyethane (DME), trimethyl phosphate (TMP), and lithium nitrate (LiNO3) was prepared. Lithium metal was immersed in the mixture for varying times between cells. Specifically, the lithium metal of the first cell was immersed in the mixture for one hour, and the lithium metal of the second cell was immersed in the mixture for two hours. The mixture was dried to remove the DME and form a composite coating on the lithium metal surface. The coated lithium metal was assembled into a symmetrical cell comprising a solid electrolyte containing LiNO3. 1+x Al x Ge 2-x (PO4)3(LAGP) and an interface layer or intermediate layer formed by the coating. For comparison, a reference symmetric cell comprising bare lithium metal and a solid electrolyte containing LAGP was also prepared. As demonstrated by various tests, the cell including the interface layer exhibited lower interfacial impedance and excellent cycle performance.

[0117] refer to Figure 2 The figure shows the electrochemical impedance spectroscopy (EIS) data of a first cell (e.g., a cell with lithium metal immersed in a mixture for one hour). Figure 3 EIS data for a second battery (e.g., a battery with lithium metal immersed in a mixture for two hours) are shown. Figure 4 EIS data for a reference cell with bare lithium metal are shown. For Figure 2 , 3 For each of the two, EIS data were collected hourly after the battery assembly without current applied for three (3) hours, and EIS data were collected every 10 cycles with current applied.

[0118] Figure 2 The impedance of the first cell (e.g., a cell with lithium metal immersed in the mixture for one hour) is shown at various times and / or after various number of cycles, particularly at the initial 230, after one (1) hour 232, after (2) hours 234, after (3) hours 236, at ten (10) cycles 238, at 20 cycles 240, at 30 cycles 242, at 40 cycles 244 and at 50 cycles 246, and more particularly Im (Z) 210 relative to Re (Z) 220.

[0119] Figure 3 The impedance of the second cell (e.g., a cell with lithium metal immersed in the mixture for two hours) is shown at various times and / or after various cycles, particularly initially 330, after one (1) hour 332, after (2) hours 334, after (3) hours 336, after ten (10) cycles 338, after 20 cycles 340, after 30 cycles 342, after 40 cycles 344 and after 50 cycles 346, and more particularly Im (Z) 310 relative to Re (Z) 320.

[0120] Figure 4 The impedance of a reference battery (e.g., a battery with bare lithium metal) is shown at various times and / or after various number of cycles, particularly at the initial 430, after one (1) hour 432, after (2) hours 434, after (3) hours 436, at ten (10) cycles 438, at 20 cycles 440, at 30 cycles 442, at 40 cycles 444 and at 50 cycles 446, and more particularly Im (Z) 410 relative to Re (Z) 420.

[0121] See Figure 2 and 4 The first cell (i.e., the cell with lithium metal immersed in the mixture for one hour) exhibited a significant reduction in impedance compared to the reference cell (i.e., the cell with bare lithium metal). Furthermore, the reference... Figure 3 and 4The second battery (i.e., the battery with lithium metal immersed in the mixture for two hours) exhibited a reduction in impedance compared to the reference battery (i.e., the battery with bare lithium metal). Similarly, Figure 3 and 4 As shown, even after 50 cycles, both the first and second cells exhibited excellent protection against impedance, with the first cell exhibiting better protection against impedance than the second cell.

[0122] refer to Figure 5 The data shows the cycling data of a first battery (e.g., a battery with lithium metal immersed in a mixture for one hour). Figure 6 This displays cycle data for a second battery (e.g., a battery with lithium metal immersed in a mixture for two hours). Figure 7 Cycle data for a reference cell with bare lithium metal is shown. For Figure 5 , 6 For each of the 7, for 50 loops, loop data is collected every 10 loops.

[0123] Figure 5 The working electrode potential (E) of the first cell (e.g., a cell having lithium metal immersed in a mixture for one hour) is shown after each number of cycles, particularly at 10 (10) cycles 530, 20 cycles 532, 30 cycles 534, 40 cycles 536, and 50 cycles 538. WE ) (V) 510 relative to time (seconds) 520.

[0124] Figure 6 The working electrode potential (E) of the second cell (e.g., a cell having lithium metal immersed in a mixture for two hours) is shown after each number of cycles, particularly at 10 (10) cycles 630, 20 cycles 632, 30 cycles 634, 40 cycles 636, and 50 cycles 638. WE (V) 610 relative to time (seconds) 620.

[0125] Figure 7 The working electrode potential (E) of the reference cell (e.g., a cell with bare lithium metal) is shown after each number of cycles, particularly at 10 (10) cycles 730, 20 cycles 732, 30 cycles 734, 40 cycles 736, and 50 cycles 738. WE (V) 710 relative to time (seconds) 720.

[0126] like Figure 5 and 6As shown, the first and second cells exhibit significantly lower potentials than the reference cell and demonstrate relatively good cycle stability. Furthermore, and as... Figure 7 As shown, the reference cell exhibits such high interfacial impedance that it cannot be cycled.

[0127] Not intending to be bound by theory, it is believed that an interface layer exists in each of the first and second cells to effectively prevent side reactions between lithium and LAGP, which in turn... Figure 2 , 3 Consistent with the EIS data shown in Figure 4. Furthermore, the interface layer is believed to prevent diffusion (e.g., of aluminum) and side reactions between lithium and LAGP. Without intending to be bound by theory, analysis of the first and second cells indicates that the first cell has more phosphorus compounds in the interface layer and, therefore, can suppress diffusion and / or side reactions better than the second cell.

[0128] For illustrative and descriptive purposes, the foregoing description of aspects has been provided. It is not intended to be exhaustive or limiting of this disclosure. Elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable where applicable and can be used in selected embodiments, even if not specifically shown or described. The same applies to variations in many ways. Such variations should not be considered as departing from this disclosure, and all such modifications are intended to be included within the scope of this disclosure.

Claims

1. A solid-state electrochemical battery for cycling lithium ions, the electrochemical battery comprising: A solid electrolyte that defines the first primary surface; Define the negative electrode of the second main surface; as well as An interface layer is disposed between the first main surface of the solid electrolyte and the second main surface of the negative electrode, wherein the interface layer includes an ion conductor disposed in an organic matrix; The interface layer is formed by a method including the following: Prepare a mixture comprising an ionic conductor precursor, an organophosphate ester, and a nonpolar organic solvent; Apply the mixture to the negative electrode; and At least a portion of the nonpolar organic solvent is removed from the mixture to form an interface layer; The organophosphates include trimethyl phosphate (TMP), triethyl phosphate, tris(1,3-dichloro-2-propyl) phosphate, tris(2-chloroethyl) phosphate, tris(1-chloro-2-propyl) phosphate, tetraethyl pyrophosphate, and tris(2-methylphenyl) phosphate, or combinations thereof.

2. The solid-state electrochemical battery according to claim 1, wherein the negative electrode comprises lithium metal.

3. The solid-state electrochemical battery according to claim 1, wherein the ion conductor comprises LiNO3, Li3PO4, Li3P, Li2PO2N (LIPON), Li3PS4, Li3ClO, LiF, Li2S, Li3N, ZnO, Al2O3, SnO2, Au, Si, Ge, Mg, Al, In, polyethylene oxide (PEO), polypropylene (PP), 1-butyl-3-methylimidazolium-bis(fluorosulfonyl)imide (BMIM-FSI), particulate graphite, acetylene black, carbon fiber, carbon nanotubes, graphene, or combinations thereof.

4. The solid-state electrochemical battery according to claim 1, wherein the ion conductor comprises LiNO3, Li3PO4, or both.

5. The solid-state electrochemical battery according to claim 1, wherein the solid electrolyte comprises Li 1+x Al x Ge 2-x (PO4)3 where 0 < x < 1 (LAGP) or Li 1+x Al x Ti 2-x (PO4)3 where 0 < x < 1 and 0 < y < 2 (LATP), Li x La y TiO3 where 0 < x < 1 and 0 < y < 1 (LLTO), Li 2+2x Zn 1-x GeO4 where 0 < x < 1 (LISICON), Li 10 GeP2S 12 (LGPS), Li 3.25 Ge 0.25 P 0.75 S4, Li4GeS4, Li6PS5Cl, Li7La3Zr2O 12 (LLZO), Li2PO2N (LIPON), or combinations thereof.

6. The solid-state electrochemical battery according to claim 1, wherein the solid electrolyte comprises Li 1+x Al x Ge 2-x (PO4)3 where 0 < x < 1 (LAGP).

7. The solid-state electrochemical cell according to claim 1, wherein the interface layer has a thickness of 10 nm or more to 500 nm or less.

8. The solid-state electrochemical cell of claim 1, wherein the mixture is applied to the negative electrode for a duration of five minutes to ten hours.

9. The solid-state electrochemical battery according to claim 1, wherein the ionic conductor precursor comprises LiNO3.

10. The solid-state electrochemical battery according to claim 1, wherein the nonpolar organic solvent comprises diethyl ether, 1,2-dimethoxyethane, 1,4-dioxane, tetraethylene glycol dimethyl ether (TEGDME), carbon tetrachloride, benzene, hexane, dichloromethane, or combinations thereof.

11. A method for manufacturing a solid-state electrochemical battery for cycling lithium-ion batteries, the method comprising: Prepare a mixture comprising an ionic conductor precursor, an organophosphate ester, and a nonpolar organic solvent; The mixture is applied to the negative electrode; as well as At least a portion of the nonpolar organic solvent is removed from the mixture to form a coating; The organophosphates mentioned therein include trimethyl phosphate (TMP), triethyl phosphate, tris(1,3-dichloro-2-propyl) phosphate, tris(2-chloroethyl) phosphate, tris(1-chloro-2-propyl) phosphate, tetraethyl pyrophosphate and tris(2-methylphenyl) phosphate, or combinations thereof.

12. The method of claim 11, further comprising: The negative electrode is positioned adjacent to the solid electrolyte, such that the coating is disposed between the negative electrode and the solid electrolyte; and The negative electrode and the solid electrolyte are pressed together, so that the coating forms an interface layer.

13. The method of claim 12, wherein the interface layer is disposed between the first main surface of the solid electrolyte and the second main surface of the negative electrode, wherein the interface layer comprises an ion conductor disposed in an organic matrix.

14. The method according to claim 12, The negative electrode contains lithium metal, and The ionic conductors mentioned above include LiNO3, Li3PO4, Li3P, Li2PO2N (LIPON), Li3PS4, Li3ClO, LiF, Li2S, Li3N, ZnO, Al2O3, SnO2, Au, Si, Ge, Mg, Al, In, polyethylene oxide (PEO), polypropylene (PP), 1-butyl-3-methylimidazolium-bis(fluorosulfonyl)imide (BMIM-FSI), particulate graphite, acetylene black, carbon fiber, carbon nanotubes, graphene, or combinations thereof.

15. The method of claim 11, wherein the mixture is applied to the negative electrode for a duration of one hour.

16. The method of claim 11, wherein the ionic conductor precursor comprises LiNO3.

17. The method of claim 11, wherein the nonpolar organic solvent comprises diethyl ether, 1,2-dimethoxyethane, 1,4-dioxane, tetraethylene glycol dimethyl ether (TEGDME), carbon tetrachloride, benzene, hexane, dichloromethane, or combinations thereof.

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