Protective materials for lithium metal anodes: their preparation and use

Abstract

A coating for protecting lithium metal sheets, particularly lithium metal anodes. The coating includes a metal fluoride, such as AlF3, and a fluoroalkylene carbonate, such as fluoroethylene carbonate (FEC). A method for using the coating includes providing a metal fluoride, providing a fluoroalkylene carbonate, mixing the metal fluoride and the fluoroalkylene carbonate using a grinding jar to obtain the coating, and then depositing and spreading the coating on a lithium sheet. The coated lithium sheet can be used in lithium-ion batteries.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority from U.S. Provisional Application No. 62 / 830,777, filed April 8, 2019, the contents of which are incorporated herein by reference in their entirety.

[0002] The present invention relates generally to controlling the reactivity of metallic lithium with an electrolyte in a battery. More specifically, the present invention relates to a protective material and its use for treating the surface of a lithium metal anode. The protective material according to the present invention comprises a metal fluoride and a fluoroalkylene carbonate. [Background technology]

[0003] Lithium metal is used as the anode in lithium-ion batteries [1]. However, for safety reasons, this use is somewhat limited. In fact, the formation of lithium dendrites can occur, which causes short circuits in the battery. Attempts to address this problem have focused on the properties of the electrolyte [2]. Typically, non-flammable electrolytes such as trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate (TBP), and triethyl phosphite (TEPi) are used. However, these electrolytes are usually reactive with lithium metal and must be used in combination with a carbonate solvent to avoid any unwanted chemical reactions.

[0004] Other research efforts aim to find ways to control the reactivity of metallic lithium with electrolytes. Various such methods have been reported, involving the use of AlF3. For example, Wang et al. have used AlF3 as a scaffold for chemical reactions with molten lithium metal to form a new composite material based on lithium aluminum alloy and lithium fluoride (LAFN) [3]. AlF3 is a compound that reacts with Li 1.2 Ni 0.15 Co 0.10 Mn 0.55 O2[4] and LiNi0.8 Co 0.15 Al 0.05 It is used in rechargeable batteries to protect the surface of high-voltage cathodes such as O2.[5] Wang et al. reported improved cycling stability of batteries using AlF3-coated LiV3O8 cathodes.[6] Tron et al. reported improved LiFePO4 aqueous battery performance after coating the cathode with 1-3 wt% AlF3.[7] AlF3 is a compound that is used to protect the surface of Li4Ti5O 12 It is used to protect cathodes, such as cathodes, and Li et al. reported that gas formation was avoided [8]. Graphite anodes were protected by AlF3 when a mixture of ammonium fluoride and aluminum nitrate was added [9].

[0005] There remains a need for methods to control the reactivity between metallic lithium and electrolytes in batteries. In particular, there remains a need for methods to protect the surface of lithium metal anodes in batteries. Additionally, there is a general need for methods to protect the lithium metal surface against reactivity with other reagents. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Xu,R et al.Artificial soft-rigid protective layer for dendrite-free lithium metal oxide.Lithium Metal Anodes(2018)28,1705838. [Non-patent document 2] Guerfi, A. et al. Improved electrolytes for Li-ion batteries: Mixtures of ionic liquid and organic electrolyte with enhanced safety and electrochemical performance. J. Power Source (2010) 195, 845 - 852.

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[0007] The present inventors have designed and prepared a material for protecting the surface of a lithium metal sheet. In particular, the present inventors have designed and implemented a method for treating the lithium metal anode surface, such as to avoid the occurrence of undesirable chemical reactions in a battery. The lithium metal anode surface is treated using a material according to the present invention.

[0008] The method according to the present invention involves the use of a protective material comprising a metal fluoride, such as aluminum trifluoride (AlF), and a fluoroalkylene carbonate, such as fluoroethylene carbonate (FEC). The method includes forming a coat of the protective material on the surface of a lithium metal anode.

[0009] Thus, according to its aspects, the present invention provides: (1) A material for protecting lithium metal sheets, comprising a metal fluoride and a fluoroalkylene carbonate. (2) The material according to (1), wherein the metal fluoride is selected from the group consisting of AlF3 and ZnF2. (3) The fluoroalkylene carbonate is a straight-chain or branched-chain C 2-15 The fluoroalkylene group or the fluoroalkylene carbonate is C 2-6 The material according to (1) or (2), comprising a fluoroalkylene group, and optionally the fluoroalkylene carbonate is cyclic. (4) Materials for protecting lithium metal sheets, including AlF3 and fluoroethylene carbonate (FEC). (5) The material according to any one of (1) to (3), wherein the metal fluoride and the fluoroalkylene carbonate are present in an amount of about 1 g and about 0.5 to 5 mL, respectively, or about 1 g and about 2 mL, respectively, or about 1 g and about 3 mL, respectively, or about 1 g and about 1 mL, respectively, or about 1 g and about 0.5 mL, respectively. (6) The material of (4), wherein AlF3 and FEC are present in an amount of about 1 g and about 0.5-5 mL, respectively, or about 1 g and about 2 mL, respectively, or about 1 g and about 3 mL, respectively, or about 1 g and about 1 mL, respectively, or about 1 g and about 0.5 mL, respectively. (7) The material according to any one of (1) to (6), wherein the lithium metal sheet is for use as an anode in a battery, and optionally the battery is a lithium ion battery. (8) The material according to any one of (1) to (7), which is stable for a period of at least about two weeks, optionally when the material is stored under a dry atmosphere, and optionally when the material is stored at ambient temperature. (9) A method for preparing a material for protecting a lithium metal sheet, comprising: (i) providing a metal fluoride; (ii) providing a fluoroalkylene carbonate; and (iii) mixing the metal fluoride and the fluoroalkylene carbonate to obtain a material, wherein optionally the metal fluoride and the fluoroalkylene carbonate are mixed in a grinding jar (such as a SPEX) equipped with grinding balls (such as zirconia balls), and optionally step (iii) is carried out at ambient temperature. (10) A method for preparing a material for protecting a lithium metal sheet, comprising: (i) providing AlF; (ii) providing fluoroethylene carbonate (FEC); and (iii) mixing the AlF and the FEC to obtain a material, wherein optionally the AlF and the FEC are mixed in a grinding jar (such as a SPEX) equipped with grinding balls (such as zirconia balls), and optionally step (iii) is carried out at ambient temperature. (11)(iv) The method of (9) or (10), further comprising storing the material, optionally wherein the material is stored under a dry atmosphere, optionally wherein the material is stored at ambient temperature, and optionally wherein the material is stored for a period of at least about two weeks. (12) A method for treating the surface of a lithium metal sheet, the method comprising: (a) providing a lithium metal sheet; (b) preparing a material comprising a metal fluoride and a fluoroalkylene carbonate; (c) depositing the material on the surface of the lithium sheet and spreading the material on the surface; and (d) drying the material, thereby forming a coat of protective material on the surface. (13) A method for treating a surface of a lithium metal sheet, the method comprising: (a) providing a lithium metal sheet; (b) preparing a material comprising AlF3 and fluoroethylene carbonate (FEC); (c) depositing the material on the surface of the lithium sheet and spreading the material on the surface; and (d) drying the material, thereby forming a coat of protective material on the surface. (14) The method of (12) or (13), wherein step (c) includes passivating the surface. (15) The method according to any one of (12) to (14), wherein step (d) is carried out at ambient temperature. (16) The method of any one of (12) to (15), wherein the lithium metal sheet is for use as an anode in a battery, and optionally the battery is a lithium ion battery. (17) A lithium metal sheet having a surface treated by the method defined in any one of (12) to (16). (18) A lithium metal sheet having a surface treated by the method defined in (13). (19) A lithium metal sheet having a surface coated with a lithium metal protective material defined in any one of (1) to (8). (20) A lithium metal sheet having a lithium metal protective material coated on its surface, the lithium metal protective material including AlF3 and fluoroethylene carbonate (FEC). (21) A lithium metal sheet according to any one of (17) to (20), for use as an anode in a battery, optionally the battery being a lithium ion battery. (22) A battery comprising a lithium metal anode having a surface treated by the method defined in any one of (12) to (16). (23) A battery comprising a lithium metal anode having a surface treated by the method defined in (13). (24) A battery comprising a lithium metal anode having a surface coated with a lithium metal protective material defined in any one of (1) to (8). (25) A battery comprising a lithium metal anode having a lithium metal protective material coated thereon, the lithium metal protective material comprising AlF3 and fluoroethylene carbonate (FEC). (26) The battery according to any one of (22) to (25), wherein the electrolyte is a non-flammable electrolyte and / or the electrolyte is a gel polymer electrolyte, and optionally, the non-flammable electrolyte is selected from the group consisting of trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate (TBP), triethyl phosphite (TEPi), and combinations thereof. (27) The battery according to any one of (22) to (26), wherein the cathode is a cathode having a nickel and / or manganese-based material, and optionally the cathode is selected from the group consisting of nickel manganese cobalt (NMC) and nickel cobalt aluminum oxide (NCA). (28) A battery comprising: a lithium metal anode having a lithium metal protection material coated thereon, the lithium metal protection material comprising a metal fluoride and a fluoroalkylene carbonate; a non-flammable electrolyte and / or a gel polymer electrolyte, optionally wherein the non-flammable electrolyte is selected from the group consisting of trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate (TBP), triethyl phosphite (TEPi), and combinations thereof; and a cathode having a nickel and / or manganese-based material, optionally wherein the cathode is selected from the group consisting of nickel manganese cobalt (NMC) and nickel cobalt aluminum oxide (NCA). (29) A battery comprising: a lithium metal anode having a lithium metal protection material coated thereon, the lithium metal protection material comprising AlF3 and fluoroethylene carbonate (FEC); a non-flammable electrolyte and / or a gel polymer electrolyte, optionally wherein the non-flammable electrolyte is selected from the group consisting of trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate (TBP), triethyl phosphite (TEPi), and combinations thereof; and a cathode having a nickel and / or manganese-based material, optionally wherein the cathode is selected from the group consisting of nickel manganese cobalt (NMC) and nickel cobalt aluminum oxide (NCA). (30) A kit for use in protecting lithium metal sheet, comprising: (a) a metal fluoride; (b) a fluoroalkylene carbonate; and (c) instructions for use. (31) A kit for use in protecting lithium metal sheet, comprising: (a) AlF3; (b) fluoroethylene carbonate (FEC); and (c) instructions for use. (32) The kit of (30) or (31), wherein the lithium metal sheet is for use as an anode in a battery, and optionally the battery is a lithium ion battery. (33) A kit for use in protecting lithium metal sheet, comprising: (a) materials comprising a metal fluoride and a fluoroalkylene carbonate; and (b) instructions for use. (34) A kit for use in protecting lithium metal sheet, comprising: (a) materials comprising AlF3 and fluoroethylene carbonate (FEC); and (b) instructions for use. (35) The kit of (33) or (34), wherein the lithium metal sheet is for use as an anode in a battery, and optionally the battery is a lithium ion battery.

[0010] Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of specific embodiments, given by way of example only with reference to the accompanying drawings.

[0011] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

[0012] The accompanying drawings include: [Brief explanation of the drawings]

[0013] [Figure 1] : Charge (C / 6) and discharge (C / 2) of Li-AlF3 with 1M LiPF6 in TMP (1 g AlF3 - 0.5 mL FEC) / / TMP / / NMC. A = time (unit = hours), B = voltage (unit = volts). [Figure 2] : Charge (C / 6) and discharge (C / 2) of Li-AlF3 with 1M LiPF6 in TMP (1 g AlF3 - 2 mL FEC) / / TMP / / NMC. A = time (unit = hours), B = voltage (unit = volts). [Figure 3] : A complex is formed between the protective material according to the invention - AlF3 and FEC. [Figure 4] : Performance of cells with standard lithium metal anodes and trimethyl phosphate (TMP) electrolyte. [Figure 5] : Performance of cells with lithium metal anodes treated with FEC only. DETAILED DESCRIPTION OF THE INVENTION

[0014] Before the present invention is further described, it is to be understood that the present invention is not limited to the specific embodiments described below. Variations of these embodiments may be made and still fall within the scope of the appended claims. It is also to be understood that the terminology used is for the purpose of describing particular embodiments, and is not intended to be limiting. Instead, the scope of the present invention will be established by the appended claims.

[0015] In order to provide a clear and consistent understanding of the terms used herein, several definitions are provided below. Furthermore, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0016] The use of the words "a" or "an" when used in conjunction with the word "comprising" in the claims and / or specification may mean "one," but is also consistent with the meanings of "one or more," "at least one," and "one or more." Similarly, the word "another" may mean at least a second or more.

[0017] As used in this specification and claims, "comprising" (and any form of comprising, such as "comprise" and "comprises"), "having" (and any form of having, such as "have" and "has"), "including" (and any form of including, such as "include" and "includes"), or "containing" (and any form of containing, such as "contain" and "contains") is inclusive or open-ended and does not exclude additional, unrecited elements or process steps.

[0018] As used herein, when referring to a numerical value or percentage, the term "about" includes the variation due to the method used to determine the value or percentage, statistical variance and human error. Further, each numerical parameter in the application should be construed in light of, at least, the number of reported significant digits and by applying ordinary rounding techniques.

[0019] As used herein, the term "alkylene" refers to a saturated divalent hydrocarbon group derived from a straight or branched chain saturated hydrocarbon by the removal of two hydrogen atoms and is exemplified by methylene, ethylene, isopropylene, and the like.

[0020] As used herein, the terms "passivation" or "passivating" refer to the technique of forming a protective layer of material on a surface to modify the chemical reactivity of the surface to external agents. In particular, the term refers to the technique of forming a layer of protective material according to the present invention on the surface of a lithium anode.

[0021] The present inventors have designed and prepared a material for protecting the surface of a lithium metal sheet. In particular, the present inventors have designed and implemented a method for treating the lithium metal anode surface, such as to avoid the occurrence of undesirable chemical reactions in a battery. The lithium metal anode surface is treated using a material according to the present invention.

[0022] The method according to the present invention involves the use of a protective material comprising a metal fluoride, such as aluminum trifluoride (AlF), and a fluoroalkylene carbonate, such as fluoroethylene carbonate (FEC). The method includes forming a coat of the protective material on the surface of a lithium metal anode.

[0023] The reactive electrolyte for metallic lithium on a surface can be controlled by passivating the lithium metal surface with a mixture containing aluminum fluoride AlF3 and fluoroethylene carbonate (FEC). The mixture is prepared by adding fluoride powder and solvent in a SPEX jar with a zirconia ball. A drop of the final mixture is deposited on the lithium metal surface and spreads, thereby forming a coating on the surface. In other words, the lithium metal surface is passivated with the mixture. The passivated lithium metal is then dried at room temperature and further assembled into a battery. Various amounts of AlF3 and FEC can be used to prepare the mixture. For example, about 1 g of AlF3 can be mixed with about 0.5 mL up to about 5 mL of FEC. In embodiments of the present invention, 1 g of AlF3 can be mixed with 0.5 mL of FEC, or 1 mL of FEC, or 2 mL of FEC, or 3 mL of FEC.

[0024] As illustrated in Figure 3, a complex is formed between AlF3 and FEC.

[0025] The present invention constitutes a novel method for protecting lithium metal anodes for storage during cycling. The present invention outlines how a mixture containing aluminum fluoride (AlF) and fluoroethylene carbonate (FEC) is beneficial to the lithium anode surface when a non-flammable electrolyte is used.

[0026] Wang et al. used AlF3 as a scaffold for chemical reaction with molten lithium metal to form a new composite based on lithium aluminum alloy and lithium fluoride (LAFN), as shown above. [3] The present invention provides a scalable method for protecting a lithium metal core with an artificial solid electrolyte interphase (SEI), i.e., a coat of protective material according to the present invention. In embodiments of the present invention, substantially no heating is involved.

[0027] The present invention is illustrated in further detail by the following non-limiting examples. [Example]

[0028] Example 1: 1 g of AlF3 was mixed with 0.5 mL of fluoroethylene carbonate (FEC) using SPEX. 10 microliters of the final slurry was deposited and spread on a lithium metal surface. The lithium metal surface was then dried at ambient temperature. The thus-treated lithium metal was used as the anode material in a coin cell in combination with an NMC 532 cathode, a Celgard 3501 separator, and 1 M LiPF6 in a trimethyl phosphate (TMP) electrolyte. 30 charge (C / 6) and discharge (C / 2) cycles are reported in Figure 1.

[0029] Example 2: 1 g of AlF3 was mixed with 2 mL of fluoroethylene carbonate (FEC). 10 microliters of the final slurry was deposited and spread on a lithium metal surface. The lithium metal surface was then dried at ambient temperature. The thus-treated lithium metal was tested in a coin cell as the anode material in combination with an NMC 532 cathode, a Celgard 3501 separator, and 1 M LiPF6 in a trimethyl phosphate (TMP) electrolyte. The cycling is reported in Figure 2.

[0030] Trimethyl phosphate (TMP) is a non-flammable solvent known to be highly reactive with lithium metal, as outlined in Figure 4. However, when used as the electrolyte in a battery where the lithium anode is treated with the protective material according to the present invention, the battery performance is improved (Figures 1-2).

[0031] Figure 5 summarizes the performance of cells with lithium metal anodes treated with FEC alone. As can be seen, FEC alone does not appear to protect the lithium metal anode from the TMP electrolyte.

[0032] Gel polymer electrolytes may also be used in embodiments of the present invention. As will be appreciated by those skilled in the art, other suitable electrolytes may be used.

[0033] An embodiment of the present invention provides a material for protecting a lithium metal sheet. The material includes a metal fluoride and a fluoroalkylene carbonate. The metal fluoride can be AlF3 or ZnF2. The fluoroalkylene carbonate can be a C fluoride, which can be linear or branched. 2-15 In an embodiment of the present invention, the fluoroalkylene carbonate may be a C 2-6 It may be a fluoroalkylene group. Optionally, the fluoroalkylene carbonate is cyclic. In an embodiment of the invention, the material comprises AlF3 and fluoroethylene carbonate (FEC), as outlined below. [ka]

[0034] The AlF3 and FEC (or metal fluoride and fluoroalkylene carbonate) are present in amounts of about 1 g and about 0.5-5 mL, respectively. In embodiments of the invention, the AlF3 and FEC (or metal fluoride and fluoroalkylene carbonate) are present in amounts of about 1 g and about 2 mL, respectively, or about 1 g and about 3 mL, respectively, or about 1 g and about 1 mL, respectively, or about 1 g and about 0.5 mL, respectively.

[0035] The protective material according to the present invention is stable for a period of at least about two weeks. The material may be stored in a dry atmosphere and / or at ambient temperature.

[0036] In the embodiments of the invention described above, the lithium metal sheet is for use as an anode in a battery, which may be a lithium ion battery.

[0037] Embodiments of the present invention provide methods for preparing protective materials and methods for treating the surface of lithium metal sheets, particularly the surface of lithium metal anodes.

[0038] Embodiments of the present invention provide lithium metal sheets, particularly lithium metal anodes, processed by the methods of the present invention. Also, embodiments of the present invention provide batteries including anodes processed by the methods of the present invention. Optionally, the electrolyte in the battery is a non-flammable electrolyte. Such electrolytes can be, for example, trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate (TBP), triethyl phosphite (TEPi), or combinations thereof. Optionally, the cathode in the battery is a cathode having a nickel and / or manganese-based material, preferably nickel manganese cobalt (NMC) or nickel cobalt aluminum oxide (NCA).

[0039] An embodiment of the present invention provides a kit for use in the protective treatment method of the present invention. As outlined above, the protective material of the present invention is stable when stored under suitable conditions. Thus, the kit can include either individual components for preparing the material, or materials that are already prepared and ready to use.

[0040] The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be accorded the broadest interpretation consistent with the description as a whole.

[0041] This description refers to several documents, the contents of which are incorporated herein by reference in their entirety. References 1.Xu,R et al.Artificial soft-rigid protective layer for dendrite-free lithium metal oxide.Lithium Metal Anodes(2018)28,1705838. 2.Guerfi,A.et al.Improved electrolytes for Li-ion batteries:Mixtures of ionic liquid and organic electrolyte with enhanced safety and electrochemical performance.J.Power Source(2010)195,845-852. 3.Wang,H.,Lin,D.,Liu,Y.,Li,Y.&Cui,Y.Ultrahigh-current density anodes with interconnected Li metal reservoir through overlithiation of mesoporous AlF3framework.Sci.Adv.(2017)3,e1701301. 4.Wang,C.&Zhang,J.Functioning Mechanism of AlF3Coating on the Li-and Mn-Rich Cathode Materials.Chem.Mater.(2014)26,6320-6327. 5.Lee,S.,Seung,C.,Amine,K.&Sun,Y.Improvement of long-term cycling performance of Li[Ni 0.8 Co 0.15 Al 0.05 ]O2by AlF3coating.J.Power Sources(2013)234,201-207. 6.Wang,H.et al.AlF3coated LiV3O8nanosheets with signifi cantly improved cycling stability as cathode material for Li-ion battery.Solid State Ionics(2013)236,37-42. 7.Tron,A.,Jo,Y.N.,Oh,S.H.,Park,Y.D.&Mun,J.Surface Modification of the LiFePO4Cathode for the Aqueous Rechargeable Lithium Ion Battery.ACS Appl.Mater.Interfaces(2017)9,12391-12399. 8.Li,W.et al.AlF3modification to suppress the gas generation of Li4Ti5O 12 anode battery.Electrochim.Acta(2014)139,104-110. 9.Chem,J.M.Enhanced performance of graphite anode materials by AlF3coating for lithium-ion batteries.J.Mater.Chemistry(2012)22,12745-12751. For example, the present invention provides the following items. (Item 1) A material for protecting lithium metal sheets, comprising a metal fluoride and a fluoroalkylene carbonate. (Item 2) The metal fluoride is AlF 3 and ZnF 2 Item 1. The material according to item 1, selected from the group consisting of: (Item 3) The fluoroalkylene carbonate is a straight-chain or branched-chain C 2-15 The fluoroalkylene carbonate may contain a fluoroalkylene group or may be selected from the group consisting of C 2-6 3. The material according to claim 1 or 2, comprising a fluoroalkylene group, optionally wherein the fluoroalkylene carbonate is cyclic. (Item 4) AlF 3 and materials for protecting the lithium metal sheet, including fluoroethylene carbonate (FEC). (Item 5) 4. The material of any one of items 1 to 3, wherein the metal fluoride and the fluoroalkylene carbonate are present in an amount of about 1 g and about 0.5-5 mL, respectively, or about 1 g and about 2 mL, respectively, or about 1 g and about 3 mL, respectively, or about 1 g and about 1 mL, respectively, or about 1 g and about 0.5 mL, respectively. (Item 6) AlF 3 and FEC are present in an amount of about 1 g and about 0.5-5 mL, respectively, or about 1 g and about 2 mL, respectively, or about 1 g and about 3 mL, respectively, or about 1 g and about 1 mL, respectively, or about 1 g and about 0.5 mL, respectively. (Item 7) 7. The material of any one of items 1 to 6, wherein the lithium metal sheet is for use as an anode in a battery, optionally the battery being a lithium ion battery. (Item 8) 8. The material of any one of items 1 to 7, which is stable for a period of at least about 2 weeks, optionally wherein the material is stored under a dry atmosphere, and optionally wherein the material is stored at ambient temperature. (Item 9) 1. A method for preparing a material for protecting a lithium metal sheet, comprising: (i) providing a metal fluoride; (ii) providing a fluoroalkylene carbonate; (iii) mixing the metal fluoride and the fluoroalkylene carbonate to obtain the material; Optionally, the metal fluoride and the fluoroalkylene carbonate are mixed in a grinding jar (such as SPEX) equipped with grinding balls (such as zirconia balls); Optionally, the method wherein step (iii) is carried out at ambient temperature. (Item 10) 1. A method for preparing a material for protecting a lithium metal sheet, comprising: (i) AlF 3 and (ii) providing fluoroethylene carbonate (FEC); (iii) AlF 3 and FEC to obtain the material; Optionally, AlF 3 and FEC are mixed in a grinding jar (e.g., SPEX) equipped with grinding balls (e.g., zirconia balls), Optionally, the method wherein step (iii) is carried out at ambient temperature. (Item 11) (iv) storing the material; Optionally, the material is stored under a dry atmosphere; Optionally, the material is stored at ambient temperature; 11. The method of claim 9 or 10, wherein the material is optionally stored for a period of at least about two weeks. (Item 12) 1. A method for treating the surface of a lithium metal sheet, comprising: (a) providing a lithium metal sheet; (b) preparing a material comprising a metal fluoride and a fluoroalkylene carbonate; (c) depositing the material onto the surface of the lithium sheet and spreading the material over the surface; (d) drying the material to form a coat of protective material on the surface. (Item 13) 1. A method for treating the surface of a lithium metal sheet, comprising: (a) providing a lithium metal sheet; (b) AlF 3 and preparing a material comprising fluoroethylene carbonate (FEC); (c) depositing the material onto the surface of the lithium sheet and spreading the material over the surface; (d) drying the material to form a coat of protective material on the surface. (Item 14) 14. The method of claim 12 or 13, wherein step (c) comprises passivating the surface. (Item 15) 15. The method according to any one of items 12 to 14, wherein step (d) is carried out at ambient temperature. (Item 16) 16. The method of any one of items 12 to 15, wherein the lithium metal sheet is for use as an anode in a battery, optionally the battery being a lithium ion battery. (Item 17) 17. A lithium metal sheet having a surface treated by the method defined in any one of items 12 to 16. (Item 18) 13. A lithium metal sheet having a surface treated by the method defined in item 13. (Item 19) A lithium metal sheet having a surface coated with the lithium metal protective material defined in any one of items 1 to 8. (Item 20) AlF 3 and a lithium metal sheet having a lithium metal protective material coated on its surface, the lithium metal protective material including fluoroethylene carbonate (FEC). (Item 21) 21. The lithium metal sheet of any one of items 17 to 20, for use as an anode in a battery, optionally wherein the battery is a lithium ion battery. (Item 22) A battery comprising a lithium metal anode having a surface treated by the method defined in any one of items 12 to 16. (Item 23) A battery comprising a lithium metal anode having a surface treated by the method defined in item 13. (Item 24) A battery comprising a lithium metal anode coated on its surface with the lithium metal protection material defined in any one of items 1 to 8. (Item 25) AlF 3 and a lithium metal anode having a lithium metal protective material coated thereon, the lithium metal protective material comprising fluoroethylene carbonate (FEC). (Item 26) 26. The battery of any one of items 22-25, wherein the electrolyte is a non-flammable electrolyte, and / or the electrolyte is a gel polymer electrolyte, optionally wherein the non-flammable electrolyte is selected from the group consisting of trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate (TBP), triethyl phosphite (TEPi), and combinations thereof. (Item 27) 27. The battery of any one of items 22-26, wherein the cathode is a cathode having a nickel and / or manganese based material, optionally the cathode is selected from the group consisting of nickel manganese cobalt (NMC) and nickel cobalt aluminum oxide (NCA). (Item 28) a lithium metal anode having a lithium metal protection material coated thereon, the lithium metal protection material comprising a metal fluoride and a fluoroalkylene carbonate; a non-flammable electrolyte and / or a gel polymer electrolyte, optionally wherein the non-flammable electrolyte is selected from the group consisting of trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate (TBP), triethyl phosphite (TEPi), and combinations thereof; a cathode having a nickel and / or manganese based material, optionally said cathode being selected from the group consisting of nickel manganese cobalt (NMC) and nickel cobalt aluminum oxide (NCA). (Item 29) -AlF 3 and a lithium metal anode having a lithium metal protective material coated thereon, the lithium metal protective material including fluoroethylene carbonate (FEC); a non-flammable electrolyte and / or a gel polymer electrolyte, optionally wherein the non-flammable electrolyte is selected from the group consisting of trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate (TBP), triethyl phosphite (TEPi), and combinations thereof; a cathode having a nickel and / or manganese based material, optionally said cathode being selected from the group consisting of nickel manganese cobalt (NMC) and nickel cobalt aluminum oxide (NCA). (Item 30) 1. A kit for use in protecting lithium metal sheet, comprising: (a) a metal fluoride; (b) a fluoroalkylene carbonate; and (c) instructions for use. (Item 31) A kit for use in protecting lithium metal sheets, comprising: (a) AlF 3 (b) fluoroethylene carbonate (FEC); and (c) instructions for use. (Item 32) 32. The kit of claim 30 or 31, wherein the lithium metal sheet is for use as an anode in a battery, optionally wherein the battery is a lithium ion battery. (Item 33) 1. A kit for use in protecting lithium metal sheet, comprising: (a) materials comprising a metal fluoride and a fluoroalkylene carbonate; and (b) instructions for use. (Item 34) A kit for use in protecting lithium metal sheets, comprising: (a) AlF 3 and fluoroethylene carbonate (FEC); and (b) instructions for use. (Item 35) 35. The kit of claim 33 or 34, wherein the lithium metal sheet is for use as an anode in a battery, optionally wherein the battery is a lithium ion battery.

Claims

1. A material for protecting a lithium metal sheet, comprising a metal fluoride and a fluoroalkylene carbonate, wherein the metal fluoride is AlF ３ and the fluoroalkylene carbonate is a linear or branched C ２－１５ A material comprising a fluoroalkylene group, and optionally said fluoroalkylene carbonate is cyclic.

2. The fluoroalkylene carbonate is C ２－６ The material of claim 1 comprising a fluoroalkylene group.

3. AlF ３ and materials for protecting the lithium metal sheet, including fluoroethylene carbonate (FEC).

4. 3. The material of any one of claims 1 to 2, wherein the metal fluoride and the fluoroalkylene carbonate are present in an amount of 1 g and 0.5 to 5 mL, respectively, or 1 g and 2 mL, respectively, or 1 g and 3 mL, respectively, or 1 g and 1 mL, respectively, or 1 g and 0.5 mL, respectively.

5. AlF ３ and FEC are present in an amount of 1 g and 0.5-5 mL, respectively, or in an amount of 1 g and 2 mL, respectively, or in an amount of 1 g and 3 mL, respectively, or in an amount of 1 g and 1 mL, respectively, or in an amount of 1 g and 0.5 mL, respectively.

6. 6. The material of any one of claims 1 to 5, wherein the lithium metal sheet is for use as an anode in a battery, optionally the battery being a lithium ion battery.

7. The material of any one of claims 1 to 6, wherein the material is stable for a period of at least 2 weeks when stored under a dry atmosphere or when the material is stored at ambient temperature.

8. 1. A method for preparing a material for protecting a lithium metal sheet, comprising: (i) providing a metal fluoride, said metal fluoride being AlF ３ And, (ii) providing a fluoroalkylene carbonate, wherein the fluoroalkylene carbonate is a C fluoroalkylene carbonate that is linear or branched; ２－１５ fluoroalkylene groups, and optionally the fluoroalkylene carbonate is cyclic; (iii) mixing the metal fluoride and the fluoroalkylene carbonate to obtain the material; Optionally, the metal fluoride and the fluoroalkylene carbonate are mixed in a grinding jar equipped with grinding balls; Optionally, the method wherein step (iii) is carried out at ambient temperature.

9. The method of claim 8, wherein the grinding balls are zirconia balls.

10. 1. A method for preparing a material for protecting a lithium metal sheet, comprising: (i) AlF ３ and (ii) providing fluoroethylene carbonate (FEC); (iii) AlF ３ and FEC to obtain the material; Optionally, AlF ３ and FEC are mixed in a grinding jar equipped with grinding balls; Optionally, the method wherein step (iii) is carried out at ambient temperature.

11. The method of claim 10, wherein the grinding balls are zirconia balls.

12. (iv) storing the material; Optionally, the material is stored under a dry atmosphere; Optionally, the material is stored at ambient temperature; 12. The method of any one of claims 8 to 11, wherein optionally the material is stored for a period of at least two weeks.

13. 1. A method for treating the surface of a lithium metal sheet, comprising: (a) providing a lithium metal sheet; (b) preparing a material comprising a metal fluoride and a fluoroalkylene carbonate, wherein the metal fluoride is AlF ３ and the fluoroalkylene carbonate is a linear or branched C ２－１５ fluoroalkylene groups, and optionally the fluoroalkylene carbonate is cyclic; (c) depositing the material onto the surface of the lithium metal sheet and spreading the material over the surface; (d) drying the material to form a coat of protective material on the surface.

14. 1. A method for treating the surface of a lithium metal sheet, comprising: (a) providing a lithium metal sheet; (b) AlF ３ and preparing a material comprising fluoroethylene carbonate (FEC); (c) depositing the material onto the surface of the lithium metal sheet and spreading the material over the surface; (d) drying the material to form a coat of protective material on the surface.

15. 15. The method of claim 13 or 14, wherein step (c) comprises passivating the surface.

16. The method of any one of claims 13 to 15, wherein step (d) is carried out at ambient temperature.

17. 17. The method of any one of claims 13 to 16, wherein the lithium metal sheet is for use as an anode in a battery, optionally the battery being a lithium ion battery.

18. A method for producing a lithium metal sheet having a surface, the method comprising treating the surface by a method as defined in any one of claims 13 to 17.

19. 15. A method of producing a lithium metal sheet having a surface, comprising treating said surface by the method defined in claim 14.

20. A lithium metal sheet having a surface coated with the lithium metal protective material defined in any one of claims 1 to 7.

21. AlF ３ and a lithium metal sheet having a lithium metal protective material coated on its surface, the lithium metal protective material including fluoroethylene carbonate (FEC).

22. 22. The lithium metal sheet of claim 20 or 21 for use as an anode in a battery, optionally the battery being a lithium ion battery.

23. A method of manufacturing a battery comprising a lithium metal anode having a surface, the method comprising treating the surface by a method defined in any one of claims 13 to 17.

24. 15. A method of manufacturing a battery comprising a lithium metal anode having a surface, the method comprising treating the surface by the method defined in claim 14.

25. A battery comprising a lithium metal anode coated on its surface with the lithium metal protection material defined in any one of claims 1 to 7.

26. AlF ３ and a lithium metal anode coated thereon with a lithium metal protective material comprising fluoroethylene carbonate (FEC).

27. ​​The battery of claim 25 or 26, wherein the battery includes an electrolyte, and the electrolyte is a non-flammable electrolyte and / or the electrolyte is a gel polymer electrolyte, and optionally, the non-flammable electrolyte is selected from the group consisting of trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate (TBP), triethyl phosphite (TEPi), and combinations thereof.

28. The battery of any one of claims 25 to 27, wherein the battery includes a cathode, and the cathode is a cathode having a nickel and / or manganese-based material, and optionally the cathode is selected from the group consisting of nickel manganese cobalt (NMC) and nickel cobalt aluminum oxide (NCA).

29. A lithium metal anode having a lithium metal protective material coated on its surface, the lithium metal protective material comprising a metal fluoride and a fluoroalkylene carbonate, wherein the metal fluoride is AlF ３ and the fluoroalkylene carbonate is a linear or branched C ２－１５ a lithium metal anode comprising a fluoroalkylene group, optionally wherein the fluoroalkylene carbonate is cyclic; a non-flammable electrolyte and / or a gel polymer electrolyte, optionally wherein said non-flammable electrolyte is selected from the group consisting of trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate (TBP), triethyl phosphite (TEPi), and combinations thereof; a cathode having a nickel and / or manganese based material, optionally said cathode being selected from the group consisting of nickel manganese cobalt (NMC) and nickel cobalt aluminum oxide (NCA).

30. -AlF ３ and a lithium metal anode having a lithium metal protection material coated thereon, the lithium metal protection material comprising fluoroethylene carbonate (FEC); a non-flammable electrolyte and / or a gel polymer electrolyte, optionally wherein said non-flammable electrolyte is selected from the group consisting of trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate (TBP), triethyl phosphite (TEPi), and combinations thereof; a cathode having a nickel and / or manganese based material, optionally said cathode being selected from the group consisting of nickel manganese cobalt (NMC) and nickel cobalt aluminum oxide (NCA).

31. A kit for use in protecting lithium metal sheet, comprising: (a) a metal fluoride; (b) a fluoroalkylene carbonate; and (c) instructions for use, wherein the metal fluoride and the fluoroalkylene carbonate are mixed and the mixture is used to protect the lithium metal sheet, and the metal fluoride is AlF ３ and the fluoroalkylene carbonate is a linear or branched C ２－１５ Optionally, the fluoroalkylene carbonate is cyclic.

32. A kit for use in protecting a lithium metal sheet, comprising: (a) AlF ３ (b) fluoroethylene carbonate (FEC); and (c) instructions for use, wherein the AlF 3 and the FEC are mixed and the mixture is used to protect the lithium metal sheet.

33. 33. The kit of claim 31 or 32, wherein the lithium metal sheet is for use as an anode in a battery, optionally the battery being a lithium ion battery.

34. A kit for use in protecting a lithium metal sheet, comprising: (a) a material comprising a metal fluoride and a fluoroalkylene carbonate; and (b) instructions for use, wherein the material is used to protect the lithium metal sheet, and the metal fluoride is AlF ３ and the fluoroalkylene carbonate is a linear or branched C ２－１５ Optionally, the fluoroalkylene carbonate is cyclic.

35. A kit for use in protecting a lithium metal sheet, comprising: (a) AlF ３ and fluoroethylene carbonate (FEC); and (b) instructions for use, wherein the material is used to protect the lithium metal sheet.

36. 36. The kit of claim 34 or 35, wherein the lithium metal sheet is for use as an anode in a battery, optionally the battery being a lithium ion battery.

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