Solvent composition for lithium metal battery

Abstract

Disclosed herein is a battery comprising: a positive current collector; a positive electrode; an electrolyte; wherein the electrolyte includes a solvent, wherein the solvent includes at least one of a fluorinated silicone and a lithium metal; and a metal current collector, where the metal current collector comprises lithium plated on the metal current collector, where a layer is coated over the lithium-plated metal current collector, where the layer comprises at least nitrogen and fluorine.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 414,813 filed on October 10, 2022, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The disclosure generally relates to lithium metal batteries. More specifically, the disclosure relates to solvent compositions for lithium metal batteries. Background Art

[0004] During the past decade, the development of viable lithium-ion (Li-ion) battery technology has been receiving increasing attention. Such developments are closely related to the future of green technology and the reduction of high carbon emission energy usage. Summary of the invention

[0005] This Summary is a high-level overview of various aspects of the invention and introduces some of the concepts that are further detailed in the Detailed Description section below. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used independently to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification, any or all of the drawings, and each claim.

[0006] An embodiment of the disclosed text relates to a battery comprising: a positive current collector; a positive electrode; an electrolyte; wherein the electrolyte comprises a solvent; wherein the solvent comprises at least one of fluorinated silicone and lithium metal; and a metal current collector; wherein the metal current collector comprises lithium plated on the metal current collector; wherein a layer is coated on the lithium-plated metal current collector; wherein the layer comprises at least nitrogen and fluorine.

[0007] In some embodiments, the battery is a lithium metal battery.

[0008] In some embodiments, the battery is a metal battery including at least one of Si, Ge, Al, Ga, Bi, Ag, Sn, or Au.

[0009] In some embodiments, the fluorinated silicone is vinyl fluoride.

[0010] In some embodiments, the thickness of the layer is less than 1000 nm.

[0011] In some embodiments, the thickness of the layer is less than 500 nm.

[0012] In some embodiments, the layer includes silicon.

[0013] In some embodiments, the ratio of fluoride to silicone in the fluorinated silicone is from 2:1 to 30:1.

[0014] In some embodiments, the concentration of the solvent is greater than 20% by volume of the electrolyte.

[0015] An embodiment of the disclosed text relates to a battery, comprising: a positive current collector; a positive electrode; an electrolyte; wherein the electrolyte comprises a solvent; wherein the solvent comprises at least one of fluorinated organosilicon or lithium metal; a metal current collector; wherein the metal current collector is substantially free of lithium metal.

[0016] In some embodiments, the battery is a lithium metal battery.

[0017] In some embodiments, the battery is a metal battery including at least one of Si, Ge, Al, Ga, Bi, Ag, Sn, or Au.

[0018] In some embodiments, the fluorinated silicone is vinyl fluoride.

[0019] In some embodiments, the ratio of fluoride to silicone in the fluorinated silicone is from 2:1 to 30:1.

[0020] In some embodiments, the concentration of the solvent is greater than 20% by volume of the electrolyte.

[0021] Embodiments of the disclosure relate to a method of forming a lithium battery, comprising: obtaining a battery; wherein the battery comprises: a positive current collector; a positive electrode; an electrolyte; wherein the electrolyte comprises a solvent; wherein the solvent comprises at least one of a fluorinated organosilicon or lithium metal; and a metal current collector; wherein the metal current collector is substantially free of lithium metal; applying 0.1 mAh / cm 2 Up to 20mAh / cm 2 and forming a coated lithium plating layer on the metal current collector; wherein the coated lithium plating layer comprises a coating layer, the coating layer comprising at least nitrogen and fluorine.

[0022] In some embodiments, the fluorinated silicone is vinyl fluoride.

[0023] In some embodiments, the thickness of the layer is less than 1000 nm.

[0024] In some embodiments, the thickness of the layer is less than 500 nm.

[0025] In some embodiments, the layer includes silicon. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments and together with the description serve to explain the principles of the disclosure.

[0027] Figure 1 A general silicone structure is shown.

[0028] Figure 2 is a schematic diagram of a cross-section of a lithium metal battery according to an embodiment of the disclosure.

[0029] Figure 3 is a schematic diagram of a cross-section of a lithium metal battery according to an embodiment of the disclosure.

[0030] Figure 4 is a schematic diagram of a cross-section of a lithium metal battery according to an embodiment of the disclosure.

[0031] Figure 5 is a schematic diagram of a cross-section of an anode-free button cell according to an embodiment of the disclosure.

[0032] Figure 6 is depicted at 4 mAh / cm according to the embodiment of the disclosure 2 Below is a graph of the discharge capacity retention from cycle 1 in an anode-free cell using the standard electrolyte composition 1M LiPF6 EC / DMC and the optimized solvent-substituted composition.

[0033] Figure 7 is depicted at 4 mAh / cm according to the embodiment of the disclosure 2 Below is a graph of the discharge capacity starting from cycle 1 in an anode-free cell using lithium salt replacement in the optimized OS3 / FEC solvent.

[0034] Figure 8 is plotted at 4 mAh / cm 2 Below is a graph of the discharge capacity retention from cycle 1 using the optimized lithium salt system 0.6M LiTFSI 0.4M LDFOB and varying the OS3 / FEC solvent ratio in an anode-free cell.

[0035] Fig. 9 is plotted at 4 mAh / cm 2 Below is a graph of the discharge capacity retention from cycle 1 in an anode-free cell using LiTFSI and LDFOB salt substitution in the optimized OS3 / FEC solvent.

[0036] Fig.10 is plotted at 4 mAh / cm 2Below is a graph of the discharge capacity retention from cycle 1 using LiFSI salt replacement in the optimized OS3 / FEC solvent in an anode-free cell.

[0037] Fig.11 is plotted at 2.5 mAh / cm 2 Graph of the discharge capacity retention from cycle 1 in anode-free cells using optimized and baseline electrolyte compositions at lower plating capacities of .

[0038] Fig.12 is depicted at 6.5 mAh / cm 2 Graph of the discharge capacity retention from cycle 1 using the optimized electrolyte composition in an anode-free cell at a higher plating capacity of . DETAILED DESCRIPTION

[0039] The following description only provides exemplary embodiments, and is not intended to limit the scope, applicability or configuration of the disclosure. On the contrary, the following description of exemplary embodiments will provide an enabling description for realizing one or more exemplary embodiments to those skilled in the art. It should be understood that, without departing from the spirit and scope of the embodiments disclosed in the present invention, various changes may be made to the function and arrangement of elements. Embodiment examples are described below with reference to the accompanying drawings. The elements of the same, similar or identical functions are identified with the same reference numerals in each of the accompanying drawings, and the repeated description of these elements is partially omitted to avoid redundancy.

[0040] In addition to those benefits and improvements already disclosed, other objects and advantages of the present invention will become apparent from the following description in conjunction with the accompanying drawings. Detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely illustrative of the present invention that can be implemented in various forms. In addition, each example given in conjunction with various embodiments of the present invention is intended to be illustrative and not restrictive.

[0041] Throughout the specification and claims, the following terms take the meanings explicitly associated with this document unless the context explicitly states otherwise. The phrases "in one embodiment" and "in some embodiments" as used herein do not necessarily refer to the same embodiment, although they may refer to the same embodiment. In addition, the phrases "in another embodiment" and "in some other embodiments" as used herein do not necessarily refer to different embodiments, although they may refer to different embodiments. Therefore, as described below, various embodiments of the present invention can be easily combined without departing from the scope or spirit of the present invention.

[0042] In addition, as used herein, the term "or" is an inclusive "or" operator and is equivalent to the term "and / or", unless the context clearly dictates otherwise. The term "based on" is not exclusive and allows for being based on additional factors that are not described, unless the context clearly dictates otherwise. In addition, throughout the specification, the meanings of "a", "an", and "the" include plural references. The meaning of "in" includes "in" and "on".

[0043] The term "based on" is not exclusive and allows for additional factors not described unless the context clearly dictates otherwise. In addition, throughout the specification, the meanings of "a", "an" and "the" include plural references. The meaning of "in" includes "in" and "on". Spatial or directional terms such as "left", "right", "inside", "outside", "above", "below" and the like should not be considered restrictive, as the present invention can take various alternative orientations. All numbers used in the specification should be understood to be modified by the term "about" in all cases. The term "about" means a range of plus or minus ten percent of the stated value.

[0044] Unless otherwise stated, all ranges or ratios disclosed herein should be understood to include any and all subranges or subratios contained therein. Unless otherwise stated, all ranges or ratios herein should be understood to be inclusive (i.e., including the minimum and maximum values ​​of such ranges or ratios). For example, a stated range or ratio of "1 to 10" should be considered to include any and all subranges between (and including the end values ​​of) a minimum of 1 and a maximum of 10; that is, all subranges or subratios starting with a minimum of 1 or greater and ending with a maximum of 10 or less, such as, but not limited to, 1 to 6.1, 3.5 to 7.8, and 5.5 to 10.

[0045] At present, secondary Li-ion battery technology using metal oxides and graphite electrodes can no longer meet the growing demand for electricity. Therefore, efforts to develop high energy density materials (such as lithium metal) are at the forefront of research. Lithium metal batteries are generally regarded as the ultimate standard for achievable energy density, due to the high theoretical capacity of lithium metal (3,860mAh / g), especially when used with high energy density cathode materials. However, the implementation of lithium metal battery technology faces practical defects, which are derived from undesirable lithium plating and dendrite formation, lithium metal instability, and volume changes experienced during cycling. These defects manifest as serious safety issues, which inhibit the commercial viability of lithium metal in secondary batteries and have attracted more attention to the subtle differences in lithium plating and SEI formation in lithium metal batteries.

[0046] Several enabling technologies have been investigated to address the shortcomings of lithium metal batteries and achieve high volumetric energy density enabled by lithium metal. Approaches include the use of nanoparticles, novel lithium host structures, high conductivity solid electrolytes, and optimized liquid electrolytes in electrode materials. Many approaches focus on modulating the protective solid electrolyte interface (SEI) formed during the initial electrolyte reduction at the negative electrode as a way to enable lithium metal technology. The SEI morphology and chemical composition are directly affected by the chemistry of the electrolyte used in the system and therefore affect battery performance and life.

[0047] Lithium salts and cyclic / linear carbonate-based electrolyte compositions (including lithium hexafluorophosphate salts in ethylene carbonate and dimethyl carbonate solvents, 1M LiPF6 EC / DMC) are commonly used in commercial applications and may limit the achievable capacity due to low thermal and chemical stability. Although the composition provides a beneficial SEI component through LiPF6 hydrolysis, the instability of LiPF6 in carbonate solvents necessitates further improvements in the electrolyte. Imide-based salts lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium bis(fluorosulfonyl)imide (LiFSI) have become promising candidates for electrolyte optimization due to their more favorable kinetics, improved chemical and thermal stability, and known contribution to SEI stability through LiF formation. In addition, LDFOB is also a potential candidate for electrolyte improvement due to the unique contribution of its oxalate reduction product to the SEI. When paired with fluorinated solvents such as fluoroethylene carbonate (FEC) and fluorosilicone-based solvents ("OS3", Silatronix), additional fluorinated components can be made available to the SEI architecture, thereby achieving higher efficiency and cycle life. These fluorosilicone-based solvents were originally developed to protect the positive electrode interface by retarding LiPF6 decomposition and subsequent HF formation. To date, these compounds have not been studied as solvents for use in lithium metal battery electrolytes. Due to the unique characteristics of the compounds, including functional Si / F groups and labile nitrile backbones, their incorporation into electrolyte compositions can reveal unique pathways for lithium plating chemistry. Downstream chemistry can allow for the formation of LixSi catalyst species, which benefit from the facile decomposition of the labile nitrile backbone. If formed, these catalyst species will allow for favorable lithium metal (Li metal) nucleation and stable deposition. The reaction mechanism can shed light on future modifications to similar catalytic chemistry, enabling a range of electrochemical techniques for improved lithium deposition through electrolyte optimization.

[0048] In some embodiments, the present specification relates to novel liquid electrolytes for realizing secondary Li metal batteries and in-situ formed anode-free Li metal batteries. In some embodiments, by applying low-capacity lithium plating (LCP), the initial formation of SEI is amplified to observe the first cycle Coulombic efficiency. This observation cannot be made when a larger plating capacity is applied, where the effect on dendrite formation is more easily seen. In some embodiments, using electrochemical methods that directly explore and separate solid electrolyte layer (SEI) formation from dendritic capacity decay, the public text describes that enables optimized electrolytes to contribute to cycle efficiency and life.

[0049] In some embodiments, the disclosure relates to batteries. In some embodiments, the battery is a metal battery. In some embodiments, the metal may include Si, Ge, Al, Ga, Bi, Ag, Sn, or Au. In some embodiments, the disclosure relates to lithium ion metal batteries. Figure 2 As depicted, in some embodiments, the disclosure relates to a lithium ion metal battery 100 after in-situ production during battery charging. In some embodiments, a lithium ion battery includes a positive current collector, a positive electrode, an electrolyte, and a metal current collector.

[0050] In some embodiments, the electrolyte includes a solvent. In some embodiments, the disclosure relates to solvent molecules for lithium ion batteries. In some embodiments, the solvent includes cations, nitrile and fluorine. In some embodiments, the cation is a metal cation. In some embodiments, the metal is a metal known to form an alloy with lithium. In some embodiments, the metal is Ge, Al, Ga, Bi, Ag, Sn, Au or Si. In some embodiments, the cation is a silicon cation.

[0051] In some embodiments, the solvent includes a fluorinated silicone. Figure 1 The general structure of the organosilicon is depicted. In some embodiments, the fluorinated organosilicon is vinyl fluoride (FEC). In some embodiments, the solvent includes lithium metal.

[0052] In some embodiments, the ratio of fluoride to silicone is from 2: 1 to 30: 1. In some embodiments, the ratio of fluoride to silicone is from 5: 1 to 30: 1. In some embodiments, the ratio is from 10: 1 to 30: 1. In some embodiments, the ratio is from 15: 1 to 30: 1. In some embodiments, the ratio is from 20: 1 to 30: 1. In some embodiments, the ratio is from 25: 1 to 30: 1.

[0053] In some embodiments, the ratio of fluoride to silicone is from 2: 1 to 25: 1. In some embodiments, the ratio is from 2: 1 to 20: 1. In some embodiments, the ratio of fluoride to silicone is from 2: 1 to 15: 1. In some embodiments, the ratio is from 2: 1 to 10: 1. In some embodiments, the ratio is from 2: 1 to 5: 1.

[0054] In some embodiments, the ratio of fluoride to silicone is from 4: 1 to 20: 1. In some embodiments, the ratio is from 12: 1 to 25: 1. In some embodiments, the ratio of fluoride to silicone is from 5: 1 to 15: 1. In some embodiments, the ratio is from 10: 1 to 25: 1. In some embodiments, the ratio is from 10: 1 to 20: 1.

[0055] In some embodiments, the volume concentration of the solvent is greater than 20% of the volume of the electrolyte. In some embodiments, the volume concentration of the solvent is 20% to 99% of the volume of the electrolyte. In some embodiments, the volume concentration is 30% to 99% of the volume of the electrolyte. In some embodiments, the volume concentration is 40% to 50% of the volume of the electrolyte. In some embodiments, the volume concentration is 50% to 99% of the volume of the electrolyte. In some embodiments, the volume concentration is 60% to 99% of the volume of the electrolyte. In some embodiments, the volume concentration is 70% to 99% of the volume of the electrolyte. In some embodiments, the volume concentration is 80% to 99% of the volume of the electrolyte. In some embodiments, the volume concentration is 90% to 99% of the volume of the electrolyte.

[0056] In some embodiments, the volume concentration of the solvent is 20% to 99% of the volume of the electrolyte. In some embodiments, the volume concentration is 20% to 90% of the volume of the electrolyte. In some embodiments, the volume concentration is 20% to 80% of the volume of the electrolyte. In some embodiments, the volume concentration is 20% to 70% of the volume of the electrolyte. In some embodiments, the volume concentration is 20% to 60% of the volume of the electrolyte. In some embodiments, the volume concentration is 20% to 50% of the volume of the electrolyte. In some embodiments, the volume concentration is 20% to 40% of the volume of the electrolyte. In some embodiments, the volume concentration is 20% to 30% of the volume of the electrolyte.

[0057] In some embodiments, the volume concentration of the solvent is 30% to 90% of the volume of the total mixture. In some embodiments, the volume concentration is 40% to 80% of the volume of the electrolyte. In some embodiments, the volume concentration is 20% to 80% of the volume of the electrolyte. In some embodiments, the volume concentration is 50% to 70% of the volume of the electrolyte. In some embodiments, the volume concentration is 60% to 80% of the volume of the electrolyte. In some embodiments, the volume concentration is 30% to 50% of the volume of the electrolyte. In some embodiments, the volume concentration is 40% to 60% of the volume of the electrolyte. In some embodiments, the volume concentration is 30% to 60% of the volume of the electrolyte.

[0058] In some embodiments, lithium is deposited on the substrate using a low area volumetric plating technique.

[0059] In some embodiments, the solvent comprises a fluoroorganosilicon-based solvent (OS3). In some embodiments, the OS3 solvent comprises FEC. In some embodiments, the ratio of OS3 to FEC is 90 / 10.

[0060] In some embodiments, the solvent comprises 0.6M LiTFSI to 2M LiTFSI. In some embodiments, the solvent comprises 1M LiTFSI to 2M LiTFSI. In some embodiments, the solvent comprises 1.5M LiTFSI to 2M LiTFSI. In some embodiments, the solvent comprises 0.6M LiTFSI to 1.5M LiTFSI. In some embodiments, the solvent comprises 0.6M LiTFSI to 1M LiTFSI. In some embodiments, the solvent comprises 1M LiTFSI to 1.5M LiTFSI. In some embodiments, the solvent comprises 0.8M LiTFSI to 1.2M LiTFSI. In some embodiments, the solvent comprises 1.5M LiTFSI to 1.8M LiTFSI. In some embodiments, the solvent comprises 1M LiTFSI to 1.2M LiTFSI.

[0061] In some embodiments, the metal current collector includes lithium plated on the metal current collector. In some embodiments, the layer is coated on the metal current collector plated with lithium. In some embodiments, the layer includes at least one of nitrogen or fluorine. In some embodiments, the layer includes silicon. In some embodiments, the lithium plated on the metal current collector leads to improved charge / discharge efficiency of the battery and extends the cycle life before the battery cell fails.

[0062] In some embodiments, the thickness of the layer is less than 5000 nm. In some embodiments, the thickness of the layer is less than 1000 nm. In some embodiments, the thickness of the layer is less than 500 nm.

[0063] In some embodiments, the battery has an area capacity of 0.1 mAh / cm 2 Up to 3mAh / cm 2 In some embodiments, the battery has an area capacity of 0.5 mAh / cm 2 Up to 3mAh / cm 2 In some embodiments, the battery has an area capacity of 1 mAh / cm 2 Up to 3mAh / cm 2 In some embodiments, the battery has an area capacity of 1.5 mAh / cm 2 Up to 3mAh / cm 2 In some embodiments, the battery has an area capacity of 2 mAh / cm 2 Up to 3mAh / cm 2 In some embodiments, the battery has an area capacity of 2.5 mAh / cm 2 Up to 3mAh / cm 2 .

[0064] In some embodiments, the battery has an area capacity of 0.5 mAh / cm 2 Up to 2.5 mAh / cm 2 In some embodiments, the battery has an area capacity of 0.5 mAh / cm 2 Up to 2mAh / cm 2 In some embodiments, the battery has an area capacity of 0.5 mAh / cm 2 Up to 1.5 mAh / cm 2 In some embodiments, the battery has an area capacity of 0.5 mAh / cm 2 Up to 1mAh / cm 2 .

[0065] In some embodiments, the battery has an area capacity of 1.5 mAh / cm 2 Up to 2.5 mAh / cm 2 In some embodiments, the battery has an area capacity of 1.5 mAh / cm 2 Up to 2mAh / cm 2 In some embodiments, the battery has an area capacity of 2 mAh / cm 2 Up to 2.5 mAh / cm 2 In some embodiments, the battery has an area capacity of 1 mAh / cm 2 Up to 2.5 mAh / cm 2 .

[0066] In some embodiments, the battery is a button cell.In some embodiments, the battery is an anode-free button cell.

[0067] In some embodiments, the lithium is deposited using a low area plating technique.

[0068] In some embodiments, the disclosure relates to metal batteries that can be sold by a manufacturer (i.e., sold prior to in-situ production). In some embodiments, the metal can include Si, Ge, Al, Ga, Bi, Ag, Sn, or Au. Figure 3 As depicted, in some embodiments, the disclosure relates to a lithium ion metal battery 110 prior to in situ production. In some embodiments, the battery includes a positive current collector, a positive electrode, an electrolyte, and a metal current collector.

[0069] In some embodiments, the electrolyte includes a solvent. In some embodiments, the disclosure relates to solvent molecules for lithium ion batteries. In some embodiments, the solvent includes cations, nitrile and fluorine. In some embodiments, the cation is a metal cation. In some embodiments, the metal is a metal known to form an alloy with lithium. In some embodiments, the metal is Ge, Al, Ga, Bi, Ag, Sn, Au or Si. In some embodiments, the cation is a silicon cation.

[0070] In some embodiments, the solvent comprises a fluorinated organosilicon. In some embodiments, the fluorinated organosilicon is fluoroethylene (FEC). In some embodiments, the solvent comprises lithium metal. In some embodiments, the solvent comprises the same properties as the above solvents.

[0071] In some embodiments, the metal current collector is substantially free of lithium metal. In some embodiments, the metal current collector is free of lithium metal or any equivalent thereof.

[0072] In some embodiments, the disclosure relates to a method for forming a battery. In some embodiments, the method includes obtaining a battery. In some embodiments, the battery is a metal battery. In some embodiments, the metal may include Si, Ge, Al, Ga, Bi, Ag, Sn or Au. In some embodiments, the disclosure relates to a lithium ion metal battery. In some embodiments, the battery includes a positive current collector, a positive electrode, an electrolyte and a metal current collector, as described above.

[0073] In some embodiments, once the battery is obtained, the method includes applying a current to the battery. In some embodiments, the current is 0.1 mAh / cm 2 Up to 20mAh / cm 2 In some embodiments, the current is within the range of 0.5 mAh / cm 2 Up to 20mAh / cm 2 In some embodiments, the current is within the range of 1 mAh / cm2 Up to 20mAh / cm 2 In some embodiments, the current is within the range of 2 mAh / cm 2 Up to 20mAh / cm 2 In some embodiments, the current is within the range of 5 mAh / cm 2 Up to 20mAh / cm 2 In some embodiments, the current is within the range of 10 mAh / cm 2 Up to 20mAh / cm 2 In some embodiments, the current is within the range of 15 mAh / cm 2 Up to 20mAh / cm 2 within the range.

[0074] In some embodiments, the current is 0.1 mAh / cm 2 Up to 15mAh / cm 2 In some embodiments, the current is within the range of 0.1 mAh / cm 2 Up to 10mAh / cm 2 In some embodiments, the current is within the range of 0.1 mAh / cm 2 Up to 5mAh / cm 2 In some embodiments, the current is within the range of 0.1 mAh / cm 2 Up to 2mAh / cm 2 In some embodiments, the current is within the range of 0.1 mAh / cm 2 Up to 1mAh / cm 2 In some embodiments, the current is within the range of 0.1 mAh / cm 2 Up to 0.5 mAh / cm 2 within the range.

[0075] In some embodiments, the current is 0.5 mAh / cm 2 Up to 2mAh / cm 2 In some embodiments, the current is within the range of 1 mAh / cm 2 Up to 10mAh / cm 2 In some embodiments, the current is within the range of 2 mAh / cm 2 Up to 5mAh / cm 2 In some embodiments, the current is within the range of 2 mAh / cm 2 Up to 10mAh / cm 2 In some embodiments, the current is within the range of 10 mAh / cm 2 Up to 15mAh / cm 2In some embodiments, the current is within the range of 0.5 mAh / cm 2 Up to 1mAh / cm 2 In some embodiments, the current is within the range of 5 mAh / cm 2 Up to 10mAh / cm 2 within the range.

[0076] In some embodiments, the method includes forming a coated lithium sheet on a metal current collector. In some embodiments, the coating of the coated lithium sheet includes at least nitrogen and fluorine. In some embodiments, the lithium plated on the metal current collector results in improved charge / discharge efficiency of the battery and extends the cycle life before the battery cell fails.

[0077] Example

[0078] Example 1: Electrode Preparation / Button Cell Assembly

[0079] Lithium cobalt (III) oxide (LCO) electrodes were prepared using 80 wt% LiCoO2, 8 wt% carbon, and 12 wt% polymer binder. The electrode disks were dried overnight at 120°C under vacuum. Button cells were prepared under argon with oxygen and water content less than 0.1 ppm. Double-layer Whatman glass fiber separators were infiltrated with 150 μl electrolyte dispensed using a 0-100 μl Thermofisher Finnpipette. The electrolyte composition was prepared under argon and mixed overnight at 850 RPM. Anode-free button cell plating area was limited to 0.6 cm in a scratched coin cell base using a 5 mil Kapton ring 2 A lithium metal battery was prepared similarly, using a 1.27 cm 2 , 300μm lithium disk and 10 mil, 1.19cm 2 Scratch treated stainless steel (SS316) pan.

[0080] The electrochemical test was performed using a Bio-Logic galvano / potentiostat. The following conditions were used for the anode-free button cell experiment: 0.3 mA / cm 2 The area current was raised to 4.2 V, followed by a constant voltage of 0.15 mA / cm 2 Finally, use 0.2mA / cm 2 The discharge area current was set to 2.75 V. The cyclic charge and discharge capacities were used to evaluate the Coulombic efficiency and discharge capacity retention of the tested electrolyte compositions. 2Lithium plating experiments were performed with charge and discharge area currents of 0.5 V or one hour as limits. Coulombic efficiency data for the tested electrolyte compositions were analyzed to evaluate SEI formation. Both experiments were performed after standing for one hour at open circuit voltage.

[0081] In some embodiments, low-area capacity plating technology (LCP) enables direct and amplified observation of the SEI through Coulombic efficiency measurements. Here, LCP is applied in a lithium metal battery configuration, where lithium is deposited on a stainless steel substrate. Figure 2 A Li metal battery 100 according to an embodiment of the disclosure is depicted. Specifically, the depicted Li metal battery 100 includes a stainless steel separator 102, a Li metal 104, a glass fiber separator 106, and a stainless steel matrix 108. In some embodiments, as Figure 2 As depicted, Li metal 104 is deposited on a stainless steel substrate 108. In some embodiments, a glass fiber separator 106 separates the stainless steel substrate 108 and the Li metal 104. Using this technique, specific contributions to the SEI can be evaluated.

[0082] Example 2: Evaluation of common salts and novel additives

[0083] Common commercial electrolyte compositions, such as LiPF6 salts dissolved in cyclic and linear carbonates such as EC / DMC / EMC, may limit lithium battery applications due to their poor thermal and chemical stability, especially when used in next-generation Li metal batteries. In order to study the effect of using ultra-low plating capacity on the formed SEI, modifications were made to optimize the electrolyte solution in Li metal half-cells.

[0084] The initial electrolyte composition used was 1M LiPF6 EC / DMC. While maintaining the lithium concentration and solvent composition, LiPF6 was substituted for LiTFSI due to its known beneficial contribution to LiF, morphological benefits to SEI, and favorable charge transfer kinetics. Table 1 depicts the LiPF6 electrolyte composition in a Li metal half-cell at 0.08 mAh / cm 2 Coulombic efficiency (CE) measurements of standard baseline and benchmark electrolyte compositions evaluated under . Salt concentrations and solvent volume ratios are given. Coulombic efficiencies for cycles 1, 10, 20, 50, 100, and 200 are shown. As depicted in Table 1, LiPF6 produces a poor first cycle efficiency of 47.3% (compared to 58.8% for 1M LiPF6EC / DMC). However, with the addition of FEC, the first cycle efficiency improves to 81.11% and exceeds the first cycle efficiency of the commercial baseline composition (1M LiPF6EC / DMC).

[0085]

[0086] Table 1

[0087] In addition, alkali metal additives (C S PF6 and KPF6) to establish a performance baseline. S PF6 and KPF6 were added to the standard electrolyte 1M LiPF6EC / DMC at 0.05M and 0.15M respectively, and the coulombic efficiency was tested. Table 2 depicts the coulombic efficiency of the Li metal half-cell at 0.08 mAh / cm 2 Coulombic efficiency measurements of novel additive electrolyte compositions evaluated under . The coulombic efficiencies for cycles 1, 10, 20, 50, 100 and 200 are shown. All solvent components of the listed electrolyte compositions are given as volume ratios, except where molar ratios are indicated by *.

[0088]

[0089] Table 2

[0090] As depicted in Table 2, the first cycle loss and subsequent cycle stability are not improved due to the small capacity exploited here that amplifies the SEI contribution.

[0091] Additional novel electrolyte formulations were also investigated, including those reported to achieve favorable lithium deposition morphology at higher plating capacities. Specifically, the ether-based composition 1.2M LiTFSIBTFE / TEP (1 / 2 molar ratio) showed no improvement in first cycle efficiency compared to the compositions depicted in Tables 1 and 2.

[0092] Example 3: Incorporation of novel OS3 solvents

[0093] In addition to the addition of FEC additives, solvent modifications were performed to incorporate additional fluorine components in an attempt to enhance the formation of LiF at the lithium metal interface. For this purpose, a fluorinated organosilicon-based solvent (OS3) was utilized in place of DEC. The 1M LiTFSI salt that showed benefit in the 90 / 10 EC-DMC / FEC system of Table 1 was used, with OS3 replacing EC / DM. Table 3 depicts the results of the LiF formation at 0.08 mAh / cm in a Li metal half-cell. 2 Coulombic efficiency measurements of electrolyte compositions optimized for favorable SEI formation evaluated below. The coulombic efficiencies for cycles 1, 10, 20, 50, 100, and 200 are shown.

[0094]

[0095] Table 3

[0096] As depicted in Table 3, the use of OS3 yields moderate benefits in first cycle loss and subsequent cycle efficiency, significantly improving the standard electrolyte performance. To further explore the benefits of OS3 solvent substitution, LiTFSI was replaced with salts LiB4 and LiPF6 that achieve high charge transfer. While both substitutions showed improvements over the standard electrolyte, neither approached the performance of the 1M LiTFSI composition.

[0097] Additional improvements were also attempted to the 1MLiTFSI 90 / 10OS3 / FEC composition using 3-methoxypropionitrile (3-MPN) instead of OS3 and using higher LiTFSI salt content. Replacing OS3 with 3-MPN did not improve the first cycle loss, however, there was a small degree of improvement in efficiency in subsequent cycles, as depicted in Table 3. No significant effect on first cycle loss and cycling stability was observed using higher LiTFSI salt concentration salts (2MLiTFSI vs. 1M LiTFSI), as depicted in Table 3. The effect of high molar lithium salt concentration on cycling efficiency at high capacity has been studied, however, the contribution of high molar lithium salt concentration to SEI formation in a scaled-up LCP experimental setup such as in this example has not been studied.

[0098] Example 4: OS3 / FEC-based electrolyte combined with LDFOB

[0099] The combination of LiBF4 and LDFOB salts in 2 / 1DEC / FEC was investigated using ultra-low plating capacity. Table 4 depicts the Li metal half-cell at 0.08 mAh / cm 2 Coulombic efficiency measurements of the electrolyte compositions combining OS3 / FEC solvent and LDFOB salt evaluated below. The coulombic efficiencies for cycles 1, 10, 20, 50, 100 and 200 are shown.

[0100]

[0101] Table 4

[0102] In the 0.6M LiBF4 0.6M LDFOB 2 / 1DEC / FEC composition, direct solvent substitution from DEC and FEC to the OS3 and FEC system produced higher first cycle efficiency, increasing from 67.06% to 82.09%, as depicted in Table 4. The composition was further improved by replacing LiTFSI with LiBF4, reducing the LDFOB concentration and increasing the relative content of OS3 (0.6MLiTFSI 0.4M LDFOB 90 / 10OS3 / FEC), as depicted in Table 4. Further increasing the LiTFSI concentration to 1M slightly reduced the first cycle loss, but maintained the cycling stability, as depicted in Table 4. Replacing LiFSI with LiTFSI in the composition did not produce a significant change in performance, with only a slight decrease in first cycle loss and post-cycle efficiency. Therefore, a beneficial interaction between the LiTFSI / LDFOB salt system in the OS3 / FEC solvent was determined.

[0103] Example 5: Effect of OS3 to FEC ratio in LiTFSI / LDFOB salt system

[0104] Within the LiTFSI / LDFOB OS3 / FEC system established in the previous round, the ratio of OS3 and FEC solvent components was varied to understand their interaction. When used alone, FEC is not stable to Li metal, but plays an important contributing role in stabilizing the solvent against continued unwanted decomposition. Although the decomposition of fluorinated organosilicon compounds allows Si and F to be incorporated into the SEI, continued decomposition is detrimental to the plating efficiency. Table 5 depicts the OS3 and FEC solvent components in a Li metal half-cell at 0.08 mAh / cm 2 Coulombic efficiency measurements of the electrolyte compositions incorporating OS3 / FEC solvent in the LiTFSI / LDFOB salt system evaluated below. The coulombic efficiencies at cycles 1, 10, 20, 50, 100, and 200 are shown.

[0105]

[0106] Table 5

[0107] As depicted in Table 5, in the LiTFSI / LDFOB salt system, increasing the FEC content from 50 / 50 to 90 / 10 slightly improves the first cycle efficiency. Here, the effect of FEC is robust over a wide range. Since the benefits of OS3 / FEC for the 1M LITFSI system have been demonstrated (again included in this table for comparison), it is clear that LDFOB and FEC are able to achieve the performance of the OS3 / FEC solvent composition.

[0108] Example 6: Transition to Dendritic Capacity Fade Observation: Battery Configuration Optimization

[0109] Increase the areal capacity from 0.1 to 1 and finally to 3 mAh / cm 2 (consistent with the areal capacity of commercial Li-ion cells) produces a systematic increase in first cycle plating efficiency. Table 6 depicts Coulombic efficiency measurements for Li metal cell configurations featuring stainless steel and copper matrices evaluated at the indicated areal capacities using electrolyte compositions 0.6M LiTFSI 0.4M LDFOB 90 / 10OS3 / FEC. Coulombic efficiencies for cycles 1, 10, 20, 50, 100, and 200 are shown.

[0110]

[0111] Table 6

[0112] Specifically, the area capacity is from 0.1 mAh / cm 2 90% of the time becomes 1 mAh / cm 2 96% of the original 2 This trend shows the effectiveness of low-area capacity plating studies as an effective tool to isolate the initial formation of the SEI from late lithium deposition. Late lithium deposition may interact differently with the electrolyte chemistry and thus obscure any initial SEI contribution interactions that may have occurred. In addition, late lithium deposition is characterized by a morphology that is different from that occurring during initial deposition. When applying LCP technology, the capacity losses associated with these phenomena are separated.

[0113] As shown, using a low plating capacity such as 0.08 mAh / cm 2 This allows for the evaluation of the SEI formed, where at higher capacities the impact of SEI formation is not clearly seen.

[0114] In the next section, we convert these Li metal current collector configurations to a LiCoO2 current collector-free anode design to evaluate the dendritic capacity fade at higher plating capacities with optimized electrolyte compositions.

[0115] Example 7: Observation of Dendritic Capacity Fading in Anode-Free Cells

[0116] Based on the SEI efficiency studies on Li metal battery devices, promising electrolytes were further investigated in an anode-free cell configuration, where a lithium cobalt oxide cathode (LiCoO2 cathode) was used and lithium plating occurred directly on a stainless steel coin cell base. Figure 3 An anode-free button cell 110 is depicted having a configuration used in a higher capacity plating analysis of dendritic capacity fade. Figure 3As depicted, an anode-free button cell 110 includes a stainless steel separator 112, LCO 114, a glass fiber separator 116, and a Kapton ring 118. Lithium is deposited directly on the stainless steel button cell base, confined within the inner diameter of the thin Kapton ring. The glass fiber serves as a separator between the stainless steel matrix and the LCO cathode. Here, a higher capacity (e.g., 4 mAh / cm 2 ) to observe the capacity decay over time, and also to observe the effect of the full spectrum of electrolyte products formed over a wider voltage range (compared to 0.08 mAh / cm on Li metal). 2 The narrow reduction range used in the experiment is used for comparison). 4 mAh / cm 2 The capacity is used as the area capacity because it exceeds the approximately 3 mAh / cm currently used in Li-ion batteries. 2 .

[0117] To explore the stability of the OS3 / FEC solvent system in a high areal capacity anode-free configuration, the solvent system was compared with EC / DMC using 1 M LiTFSI salt. Table 7 depicts the first cycle irreversible losses of the electrolyte compositions. Figure 4 Depicted at 4 mAh / cm 2 Discharge capacity retention from cycle 1 in anode-free cells using standard electrolyte composition 1M LiPF6 EC / DMC and optimized solvent-substituted compositions. As depicted in Table 7, the new solvent substitution results in significantly improved first cycle efficiency (irreversible losses of 4.49% and 39.69% for 1M LiTFSI 90 / 10OS3 / FEC and 1M LiTFSI EC / DMC, respectively).

[0118]

[0119] Table 7

[0120] like Figure 4 As depicted, improvements were observed up to 20 cycles, with the OS3 / FEC substituted composition retaining greater than 50% of the discharge capacity (compared to approximately 30% discharge capacity retention for the EC / DMC substituted composition). This effect on discharge capacity was also observed using 1M LiPF6 salt and the same solvent substitution, but to a lesser extent. Here, the OS3 / FEC substituted composition improved in irreversible losses compared to the EC / DMC composition, but exhibited similar performance in subsequent cycles.

[0121] Example 8: Effect of common lithium salts in OS3 / FEC solvent system

[0122] Since the previous section has confirmed that the OS3 / FEC solvent system produces low first cycle loss and stable capacity retention up to 20 cycles when using LiTFSI, other commonly used lithium salts are used to further explore the properties of the solvent. LiTFSI is used to replace LiBF4, LiPF6 and LiFSI, and compared with the composition (0.6M LiTFSI0.4M LDFOB 90 / 10) previously optimized using SEI observation experiments. Table 8 depicts the first cycle irreversible loss of the electrolyte composition. Figure 5 Depicted at 4 mAh / cm 2 Discharge capacity retention from cycle 1 using lithium salt replacement in optimized OS3 / FEC solvent in anode-free cells.

[0123]

[0124] Table 8

[0125] As shown in Table 8 and Figure 5 As depicted, LDFOB in combination with LiFSI or LiTFSI salts proved to be highly beneficial. Moreover, LiBF4 was found to be detrimental in the system, which had the lowest initial cycle loss and showed a greater performance degradation with increasing cycle number.

[0126] Example 9: Effect of OS3 / FEC Solvent Ratio in LiTFSI and LDFOB Salt System

[0127] As mentioned in the previous section, FEC enables stabilization of fluorosilicones. The OS3 / FEC solvent system was optimized using the salt system 0.6M LiTFSI 0.4M LDFOB. OS3 was shown to be a robust solvent, with FEC being an effective contributing component to improve capacity retention and reduce first cycle losses by stabilizing the SEI film and subsequent decomposition of the OS3 solvent. Table 9 depicts the first cycle irreversible losses of the electrolyte compositions. Figure 6 Depicted at 4 mAh / cm 2 The discharge capacity retention rate from cycle 1 using the lithium salt system 0.6M LiTFSI 0.4M LDFOB in the anode-free battery and changing the OS3 / FEC solvent ratio. From Table 9 and Figure 6 As can be seen in Figure 2, omitting FEC from the solvent resulted in immediate and continuous electrolyte decomposition and poor performance, while only 2% was highly effective in stabilizing the system, yielding <3% irreversible losses and high cycle efficiency. From this round of optimization, excess FEC was found to be detrimental, with 8% to 10% proving to be most beneficial.

[0128]

[0129] Table 9

[0130] Example 10: Effect of LiTFSI and LDFOB salt ratio in optimized OS3 / FEC solvent system

[0131] After isolating the interaction between LDFOB concentration and the optimized solvent 90 / 10 OS3 / FEC, the interaction between LDFOB and LiTFSI was explored. Table 10 depicts the first cycle irreversible losses of the electrolyte compositions. Figure 7 Depicted at 4 mAh / cm 2 The discharge capacity retention from cycle 1 was obtained by replacing LiTFSI and LDFOB salts in the optimized OS3 / FEC solvent in the anode-free cell. Figure 7 As depicted, the difference in first cycle irreversible losses between the compositions is less than 1% when varying the LDFOB and LITFSI concentrations as shown. While concentrations above 0.4M LDFOB slightly reduce the benefit on first cycle losses, above 0.2M is necessary to achieve high efficiencies up to 20 cycles when paired with LiTFSI. As shown in Table 6, when comparing single salt 1M LiTFSI compositions with and without LDFOB, it is clear that a critical amount of LDFOB is required to achieve high discharge capacity retention in the OS3 / FEC solvent system.

[0132]

[0133] Table 10

[0134] Example 11: Effect of LiFSI and LDFOB salt ratio in optimized OS3 / FEC solvent system

[0135] As shown above, in the three-salt system with 90 / 10 OS3 / FEC, LiFSI salt is beneficial. The interaction between LiFSI and LDFOB in the system was further explored by varying the LiFSI concentration. Table 11 depicts the first cycle irreversible losses of the electrolyte compositions. Figure 8 Depicted at 4 mAh / cm 2 The discharge capacity retention from cycle 1 is shown in Table 11 and Table 12 when LiFSI salt is used as a replacement in the optimized OS3 / FEC solvent in the anode-free cell. Figure 8 As shown, in the optimized 0.6 M LiTFSI 0.4 M LDFOB 90 / 10OS3 / FEC composition, LiFSI was confirmed to be a successful LiTFSI substitute, however, concentrations exceeding 1 M were detrimental in the system.

[0136]

[0137] Table 11

[0138] Example 12: Baseline composition and optimized composition at 2.5 mAh / cm 2 and 6.5mAh / cm 2 Capacity decay under

[0139] At lower plating capacity (2.5 mAh / cm 2 ), where irreversible losses are generally expected to be higher, similar trends are found for the optimized salt and solvent systems as well as for the more ubiquitous benchmark compositions (1M LiPF6 EC / DMC) and those in the literature (0.6M LiBF4 0.6M LDFOB 2 / 1DEC / FEC), as shown in Tables 12 and Fig. 9 Extremely high plating capacities (6.5 mAh / cm 2 ), as shown in Table 13 and Fig.10 At lower plating capacities, the LiTFSI / LDFOB and OS3 / FEC relationships identified in the previous section proved to be robust, and the optimized electrolyte compositions (0.6M LiTFSI 0.4M LDFOB 90 / 10OS3 / FEC and 1M LiTFSI 0.4M LDFOB 90 / 10OS3 / FEC) showed comparable performance to 4 mAh / cm 2 The plating experiments showed a similar trend. 2 ), the first cycle loss was only slightly improved, indicating the robustness of the first cycle efficiency of these optimized compositions.

[0140]

[0141] Table 12

[0142] Other embodiments of the disclosed text can be found in Appendix A, which is incorporated herein by reference.

[0143] Of course, the foregoing examples are illustrative rather than limiting.

[0144] Although several embodiments of the disclosure have been described, it should be understood that these embodiments are merely illustrative and non-restrictive, and that many modifications may become apparent to those of ordinary skill in the art. In addition, the various steps may be performed in any desired order (and any desired steps may be added and / or any desired steps may be eliminated).

Claims

1. A battery comprising: Positive electrode current collector; Positive electrode; Electrolytes; wherein the electrolyte comprises a solvent; wherein the solvent comprises at least one of fluorinated organosilicon and lithium metal; and Metal current collector; wherein the metal current collector comprises lithium, wherein the lithium is plated on the metal current collector; wherein a layer is coated on the lithium-plated metal current collector; Wherein the layer comprises at least nitrogen and fluorine.

2. The battery according to claim 1, wherein the battery is a lithium metal battery.

3. The battery according to claim 1, wherein the battery is a metal battery including at least one of Si, Ge, Al, Ga, Bi, Ag, Sn or Au. The battery according to claim 1 , wherein the fluorinated organosilicon is vinyl fluoride. The battery of claim 1 , wherein the layer has a thickness of less than 1000 nm. The battery of claim 1 , wherein the layer has a thickness of less than 500 nm.

7. The battery of claim 1, wherein the layer comprises silicon.

8. The battery of claim 1, wherein the ratio of fluoride to silicone in the fluorinated silicone is 2:1 to 30:

1.

9. The battery of claim 1, wherein the concentration of the solvent is greater than 20% by volume of the electrolyte.

10. A battery comprising: Positive electrode current collector; Positive electrode; Electrolytes; wherein the electrolyte comprises a solvent; wherein the solvent comprises at least one of fluorinated organosilicon or lithium metal; a metal current collector; The metal current collector is substantially free of lithium metal.

11. The battery of claim 10, wherein the battery is a lithium metal battery.

12. The battery according to claim 10, wherein the battery is a metal battery including at least one of Si, Ge, Al, Ga, Bi, Ag, Sn or Au.

13. The battery of claim 10, wherein the fluorinated organosilicon is vinyl fluoride.

14. The battery of claim 10, wherein the ratio of fluoride to silicone in the fluorinated silicone is 2:1 to 30:

1.

15. The battery of claim 10, wherein the concentration of the solvent is greater than 20% by volume of the electrolyte.

16. A method of forming a lithium battery, comprising: Get the battery; The battery comprises: Positive electrode current collector; Positive electrode; Electrolytes; wherein the electrolyte comprises a solvent, wherein the solvent comprises at least one of fluorinated organosilicon or lithium metal; and Metal current collector; wherein the metal current collector is substantially free of lithium metal; Apply 0.1 mAh / cm 2 Up to 20mAh / cm 2 current within the range; and forming a coated lithium plating layer on the metal current collector; The coated lithium plating layer comprises a coating layer, and the coating layer comprises at least nitrogen and fluorine.

17. The battery of claim 16, wherein the fluorinated organosilicon is vinyl fluoride.

18. The battery of claim 16, wherein the layer has a thickness of less than 1000 nm.

19. The battery of claim 16, wherein the layer has a thickness of less than 500 nm.

20. The battery of claim 16, wherein the layer comprises silicon.

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