Electrolyte formulations for electrochemical cells

Abstract

Some aspects of the present disclosure are generally related to electrolyte formulations for use in electrochemical cells, for example, lithium metal batteries. In some embodiments, the electrolyte comprises a fluorinated cyclic carbonate, an unfluorinated linear ester, an unfluorinated ether, a fluorinated ester, a fluorinated ether, a sulfonamide, and / or one or more salts. In some embodiments, ratios between the components of the electrolyte formulations are disclosed, where such ratios improve the performance of the electrochemical cell comprising the electrolyte. The components and / or ratio of components of the electrolyte formulations disclosed herein may facilitate improved control over the formation and / or composition of a solid electrolyte interphase (SEI) that may form on one or more electrodes of the electrochemical cells. Additionally, some aspects are generally directed to related methods of making and / or using the electrochemical cells.

Description

[0001] ELECTROLYTE FORMULATIONS FOR ELECTROCHEMICAL CELLS RELATED APPLICATIONS

[0002] This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application Serial No. 63 / 738,320, filed December 23, 2024, and entitled “Electrolyte Formulations for Electrochemical Cells,” which is incorporated herein by reference in its entirety for all purposes.

[0003] TECHNICAL FIELD

[0004] Electrolyte formulations for electrochemical cells and related methods are generally described.

[0005] BACKGROUND

[0006] Electrochemical cells convert chemical energy into electrical energy by coupling electrochemical reactions at a cathode and anode. Anodes comprising lithium (e.g., lithium metal) can be reactive with species present in the electrolyte of the electrochemical cell and form a solid-electrolyte interphase (SEI) between the anode and the electrolyte upon reacting with such species. Conventionally, SEIs mitigate the reactivity between the anode and the electrolyte but may also limit lithium-ionic conductivity to the anode and / or be thermally unstable during cycling of the electrochemical cell, and therefore may detract from the electrochemical cell performance.

[0007] Accordingly, improved electrolytes and associated SEIs for electrochemical cells are needed.

[0008] SUMMARY

[0009] Electrolyte formulations for electrochemical cells and related methods are generally described. The subject matter of the present disclosure involves, in some cases, interrelated products, alternative solutions to a particular problem, and / or a plurality of different uses of one or more systems and / or articles.

[0010] In some embodiments, electrochemical cells are described.

[0011] #14755643vlIn some embodiments, an electrochemical cell comprises an electrode comprising lithium metal and a localized high-concentration electrolyte, wherein the localized high-concentration electrolyte comprises a coordinating solvent, a non-solvating diluent, a sultone, and LiBF4.

[0012] In some embodiments, an electrochemical cell comprises an electrode comprising lithium metal and an electrolyte, wherein the electrolyte comprises a fluorinated cyclic carbonate, an unfluorinated linear ester, and a fluorinated ether, wherein a weight ratio of the fluorinated cyclic carbonate to a combined weight of the unfluorinated linear ester and the fluorinated ether is greater than or equal to 0.25 and less than or equal to 1, and wherein a weight ratio of the unfluorinated linear ester to the fluorinated ether is greater than or equal to 0.25 and less than or equal to 4.

[0013] In some embodiments, an electrochemical cell comprises an electrode comprising lithium metal and an electrolyte, wherein the electrolyte comprises a fluorinated cyclic carbonate, an unfluorinated linear ester, and a fluorinated sulfonamide, wherein a weight ratio of the fluorinated cyclic carbonate to a combined weight of the unfluorinated linear ester and the fluorinated sulfonamide is greater than or equal to 0.25 and less than or equal to 1, and wherein a weight ratio of the unfluorinated linear ester to the fluorinated sulfonamide is greater than or equal to 0.25 and less than or equal to 4.

[0014] In some embodiments, an electrochemical cell comprises an electrode comprising lithium metal and an electrolyte, wherein the electrolyte comprises a fluorinated cyclic carbonate, an unfluorinated linear ester, and a fluorinated linear ester, wherein a weight ratio of the fluorinated cyclic carbonate to a combined weight of the unfluorinated linear ester and the fluorinated linear ester is greater than or equal to 0.25 and less than or equal to 1, and wherein a weight ratio of the unfluorinated linear ester to the fluorinated linear ester is greater than or equal to 0.25 and less than or equal to 4.

[0015] In some embodiments, methods are described. In some embodiments, the method comprises cycling an electrochemical cell, wherein the electrochemical cell comprises an electrode comprising lithium metal, the electrochemical cell comprises an electrolyte, the electrolyte comprises a sultone and LiBF4, the electrolyte comprises a fluorinated ether, a fluorinated sulfonamide, and / or a fluorinated ester, and the cycling is performed under an anisotropic force normal to a surface of the electrode comprising lithium metal.

[0016] #14755643vlIn some embodiments, the method comprises cycling an electrochemical cell, wherein the electrochemical cell comprises an electrode comprising lithium metal, the electrochemical cell comprises a localized high-concentration electrolyte, and the localized high concentration electrolyte comprises a coordinating solvent, a nonsolvating diluent, a sultone, and LiBF4.

[0017] Other advantages and novel features of the present disclosure will become apparent from the following detailed description of various non-limiting embodiments of the disclosure when considered in conjunction with the accompanying figures. In cases where the present specification and a document incorporated by reference include conflicting and / or inconsistent disclosure, the present specification shall control.

[0018] BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Non-limiting embodiments of the present disclosure will be described by way of example with reference to the accompanying figures, which are schematic and are not intended to be drawn to scale unless otherwise indicated. In the figures, each identical or nearly identical component illustrated is typically represented by a single numeral. For purposes of clarity, not every component is labeled in every figure, nor is every component of each embodiment of the disclosure shown where illustration is not necessary to allow those of ordinary skill in the art to understand the disclosure. In the figures:

[0020] FIGS. 1A-1B are schematic diagrams of electrochemical cells, according to some embodiments;

[0021] FIG. 2 is a schematic diagram of a vehicle in which an electrochemical cell may be used, according to some embodiments;

[0022] FIG. 3 is a plot of discharge capacity as a function of charge-discharge cycle number for electrochemical cells, according to some embodiments;

[0023] FIG. 4 is a plot of 5-minute discharge resistance as a function of charge-discharge cycle number for electrochemical cells, according to some embodiments;

[0024] FIG. 5 is a plot of discharge capacity as a function of charge-discharge cycle number for electrochemical cells, according to some embodiments;

[0025] FIG. 6 is a plot of 5-minute discharge resistance as a function of charge-discharge cycle number for an electrochemical cell, according to some embodiments;

[0026] #14755643vlFIG. 7 is a plot of discharge capacity as a function of charge-discharge cycle number for electrochemical cells, according to some embodiments;

[0027] FIG. 8 is a plot of 5-minute discharge resistance as a function of charge-discharge cycle number for electrochemical cells, according to some embodiments;

[0028] FIGS. 9-10 are plots of the volume of gas generated by electrochemical cells after storage, according to some embodiments;

[0029] FIGS. 11-12 are plots of discharge capacity as a function of charge-discharge cycle number for electrochemical cells, according to some embodiments;

[0030] FIG. 13 is a plot of the volume of gas generated by electrochemical cells after storage, according to some embodiments;

[0031] FIG. 14 is a plot of discharge capacity as a function of charge-discharge cycle number for electrochemical cells, according to some embodiments;

[0032] FIG. 15 is a plot of 5-minute discharge resistance as a function of chargedischarge cycle number for electrochemical cells, according to some embodiments;

[0033] FIGS. 16-23 are plots of discharge voltage vs. cycle number for symmetric lithium metal cells having various electrolyte compositions, according to some embodiments;

[0034] FIG. 24 is a XRD depth profile of SEIs formed on a lithium film and a separator, according to some embodiments;

[0035] FIGS. 25A-25B are XRD spectra of SEIs formed on a lithium film and a separator, respectively, according to some embodiments;

[0036] FIGS. 26A-26B are XRD spectra of SEIs formed on a lithium film and a separator, respectively, according to some embodiments;

[0037] FIG. 27 is a plot showing the gas generated in various electrochemical cells, according to some embodiments;

[0038] FIG. 28 is a plot showing the discharge capacity as a function of cycle for two electrochemical cells, according to some embodiments;

[0039] FIG. 29 is a plot showing discharge resistance as a function of cycle for two electrochemical cells, according to some embodiments; and

[0040] FIG. 30 is a plot showing rate capacity for various electrochemical cells, according to some embodiments.

[0041] #14755643vlDETAILED DESCRIPTION

[0042] Some aspects of the present disclosure are generally related to electrolyte formulations for use in electrochemical cells, for example, lithium metal batteries. In some embodiments, the electrolyte comprises a fluorinated cyclic carbonate, an unfluorinated linear ester, a fluorinated ester, a fluorinated ether, a sulfonamide, and / or one or more salts. In some embodiments, the electrolyte is a localized high-concentration electrolyte, such as a localized high-concentration electrolyte comprising a coordinating solvent, a non-solvating diluent, a sultone, and LiBF4. It is also possible for the electrolyte to be an electrolyte other than a localized high-concentration electrolyte.

[0043] In some embodiments, ratios between the components of the electrolyte formulations are disclosed, where such ratios improve the performance of the electrochemical cell comprising the electrolyte. The components and / or ratio of components of the electrolyte formulations disclosed herein may facilitate improved control over the formation and / or composition of a solid electrolyte interphase (SEI) that may form on one or more electrodes of the electrochemical cells. Additionally, some aspects are generally directed to related methods of making and / or using the electrochemical cells.

[0044] The formation and / or composition of an SEI may impact the performance of electrochemical cells, for example, by decreasing polarization loss associated with the SEI. Additionally, gas generation (e.g., gassing) may be a particular problem in the context of electrochemical cells (e.g., decomposition of an SEI present on a lithium containing electrode of an electrochemical cell). Some electrolyte formulations described herein pertain to electrochemical cells that may advantageously provide control over the formation and / or composition of the SEI in the electrochemical cell, which may improve electrochemical cell performance and / or reduce gassing within the electrochemical cell. In some embodiments, the SEI formed using the electrolyte formulations described herein have increased thermal stability and / or provide increased protection to an underlying electrode (e.g., comprising lithium).

[0045] In one aspect, an electrochemical cell is provided. An electrochemical cell generally comprises an electrode and an electrolyte. An electrode may comprise an active material (e.g., an anode active or cathode active material), as discussed in greater detail below. In some embodiments, an electrode comprises lithium. The electrochemical

[0046] #14755643vlcell itself may comprise or be a lithium metal cell. FIG. 1A provides a non-limiting, cross-sectional schematic illustration of electrochemical cell 40. As shown in FIG. 1A, electrochemical cell 40 comprises first electrode 42 (e.g., an anode), second electrode 44 (e.g., a cathode), and electrolyte 46 disposed between first electrode 42 and second electrode 44. In this example embodiment, an active surface 50 of the first electrode 42 and an active surface 56 of the second electrode 44 both contact the electrolyte 46. Note that while direct contact between the active surfaces of the electrodes and the electrolyte is illustrated in the embodiment of FIG. 1A, additional layers (e.g., a protective layer and / or SEIs as described in more detail elsewhere herein) are also possible between the active surfaces of the electrodes and the electrolyte, thereby preventing direct contact between the active surfaces and the electrolyte.

[0047] The electrochemical cell may optionally include a separator disposed between the first electrode and the second electrode. In some embodiments, the separator comprises porous separator materials that contain a non-solid electrolyte (e.g., a liquid electrolyte). For example, referring to FIG. 1A, a porous separator (not shown) may be used to house at least a portion of electrolyte 46 and may be positioned between first electrode 42 and second electrode 44. It is also possible that, in some embodiments, the electrolyte may be or comprise a solid-state electrolyte or gel electrolyte that functions as a separator in addition to its electrolyte function. The electrochemical cell may further include one or more current collectors, e.g., current collectors 52 and 54 as shown in FIG. 1A.

[0048] FIG. IB is another cross-sectional schematic diagram of electrochemical cell 40, but after performing one or more charge / discharge cycles within the electrochemical cell. In this instance, a solid electrolyte interphase (SEI) 49 has formed over-active surface 50 of first electrode 42 (e.g., an anode) following the one or more charge-discharge cycles, thereby preventing or reducing further direct contact between the first electrode 42 and electrolyte 46.

[0049] The electrochemical cells described herein may comprise an electrolyte. The electrolyte can function as a medium for the storage and transport of ions, and in the special case of solid electrolytes and gel electrolytes, these materials may additionally function as a separator between an anode and a cathode. The electrolyte may comprise a liquid, solid, or gel material capable of storing and transporting ions (e.g., lithium ions) between the anode and the cathode. The electrolyte may be electronically non-conductive

[0050] #14755643vl-1-to prevent short circuiting between an anode and a cathode. In some embodiments, the electrolyte may comprise, consist of, and / or consist essentially of a non-solid electrolyte.

[0051] In some embodiments, an electrochemical cell described herein comprises a localized high-concentration electrolyte. The localized high-concentration electrolyte may comprise a coordinating solvent, a non-solvating diluent, and one or more salts. In some localized high-concentration electrolytes, the coordinating solvent coordinates and / or solubilizes ions from the salt that are present in the electrolyte but the nonsolvating diluent does not. This can result in electrolytes comprising regions that have locally enhanced concentrations of ions. It is believed that both anions and solvent molecules coordinate the cations present in such regions, and that such regions comprise contact ion pairs and / or aggregated species. It is also believed that such electrolytes as a whole include relatively low amounts of free, uncoordinated solvent and relatively low amounts of solvent- separated ion pairs. As solvent- separated ion pairs can be prone to undesirable redox reactions at electrode interfaces, and solvents can undesirably decompose at electrode interfaces to form organic species, localized high-concentration electrolytes are believed to advantageously exhibit fewer such reactions than other types of electrolytes.

[0052] Additionally, it is also believed that, when electrochemical cells comprising localized high-concentration electrolytes are cycled, the electrode-electrolyte interphases with the anode (i.e., the SEI) and / or the cathode (i.e., the CEI) that form are desirably rich in inorganic compounds. It is believed that, upon cycling and / or during electrochemical operations (e.g., thermal storage, calendar aging, abuse testing), the contact ion pairs and aggregated species present in such electrolytes decompose to form anion-derived and / or inorganic species, which, when incorporated into the SEI and / or the CEI, are believed to protect the electrodes and improve cycle life.

[0053] As noted above, some electrolytes described herein are not localized high-concentration electrolytes.

[0054] An electrolyte of the electrochemical cell may comprise one or more solvents, according to some embodiments. When present in a localized high-concentration electrolyte, such solvents may be considered to be coordinating solvents if they coordinate one or more ions present therein (e.g., Li+ions present therein) and may be considered to be non-solvating diluents if they do not solubilize such ions. Some solvents

[0055] #14755643vlthat are present may be considered to be neither coordinating solvents nor non-solvating diluents. It should also be noted that some localized high-concentration electrolytes may comprise two or more coordinating solvents, two or more non-solvating diluents, and / or two or more solvents that are neither coordinating solvents nor non- solvating diluents. Non-limiting examples of suitable coordinating solvents include ethers (e.g., unfluorinated ethers), carbonates, esters, sulfones, sulfoxides, nitriles, and fluorinated solvents that coordinate ions (e.g., fluorinated solvents that coordinate Li+ions). Nonlimiting examples of suitable non-solvating diluents include fluorinated ethers, low polarity hydrocarbons, and fluorinated orthoformates (e.g., tris(2, 2, 2, -trifluoroethyl) orthoformate).

[0056] The electrolytes described herein may comprise coordinating solvents in a variety of suitable amounts. In some embodiments, a coordinating solvent may be present in an amount of greater than or equal to 10 wt%, greater than or equal to 15 wt%, greater than or equal to 20 wt%, greater than or equal to 25 wt%, or greater than or equal to 30 wt% of the electrolyte. In some embodiments, a coordinating solvent may be present in an amount of less than or equal to 35 wt%, less than or equal to 30 wt%, less than or equal to 25 wt%, less than or equal to 20 wt%, or less than or equal to 15 wt% of the electrolyte. Combinations of the above -referenced ranges are also possible (e.g., greater than or equal to 10 wt% and less than or equal to 35 wt%). Other ranges are also possible.

[0057] In some embodiments, wherein the electrolyte comprises multiple coordinating solvents, each coordinating solvent may independently be present in the electrolyte in an amount that corresponds to the foregoing ranges and / or all of the coordinating solvents together may make up an amount of the electrolyte that corresponds to the foregoing ranges. In some such cases, the amounts of each coordinating solvent may be equal to each other. In other such cases, the amounts of each coordinating solvent may be different from each other.

[0058] The electrolytes described herein may comprise non- solvating diluents in a variety of suitable amounts. In some embodiments, a non-solvating diluent may be present in an amount of greater than or equal to 30 wt%, greater than or equal to 35 wt%, greater than or equal to 40 wt%, greater than or equal to 45 wt%, greater than or equal to 50 wt%, greater than or equal to 55 wt%, greater than or equal to 60 wt%, or greater than

[0059] #14755643vlor equal to 65 wt% of the electrolyte. In some embodiments, a non-solvating diluent may be present in an amount of less than or equal to 70 wt%, less than or equal to 65 wt%, less than or equal to 60 wt%, less than or equal to 55 wt%, less than or equal to 50 wt%, less than or equal to 45 wt%, less than or equal to 40 wt%, or less than or equal to 35 wt% of the electrolyte. Combinations of the above-referenced ranges are also possible (e.g., greater than or equal to 30 wt% and less than or equal to 70 wt%). Other ranges are also possible.

[0060] In some embodiments, wherein the electrolyte comprises multiple non- solvating diluents, each non-solvating diluent may independently be present in the electrolyte in an amount that corresponds to the foregoing ranges and / or all of the non-solvating diluents together may make up an amount of the electrolyte that corresponds to the foregoing ranges. In some such cases, the amounts of each non-solvating diluent may be equal to each other. In other such cases, the amounts of each non-solvating diluent may be different from each other.

[0061] When an electrolyte comprises a coordinating solvent and a non-solvating diluent, these species may be present in a variety of suitable relative amounts. In some embodiments, the molar ratio of the total amount of coordinating solvents in the electrolyte to the total amount of non- solvating diluents in the electrolyte is greater than or equal to 0.3, greater than or equal to 0.5, greater than or equal to 0.75, greater than or equal to 1, greater than or equal to 1.25, greater than or equal to 1.5, or greater than or equal to 1.75. In some embodiments, the molar ratio of the total amount of coordinating solvents in the electrolyte to the total amount of non- solvating diluents in the electrolyte is less than or equal to 2, less than or equal to 1.75, less than or equal to 1.5, less than or equal to 1.25, less than or equal to 1, less than or equal to 0.75, or less than or equal to 0.5. Combinations of the above-referenced ranges are also possible (e.g., greater than or equal to 0.3 and less than or equal to 2). Other ranges are also possible.

[0062] In some embodiments, an electrolyte may comprise a non-aqueous solvent. Nonlimiting examples of non-aqueous electrolyte solvents include, but are not limited to, non-aqueous organic solvents, such as, for example, carbonates (described in more detail elsewhere herein), an organic amide (e.g., N-methyl acetamide), acetonitrile, acetals (e.g., cyclic or non-cyclic acetals), ketals, esters, sulfones, sulfites, sulfonamides (e.g., asymmetric sulfonamides), sulfolanes, aliphatic ethers, cyclic ethers, acid esters (e.g.,

[0063] #14755643vlorganic or inorganic acid esters), glymes, polyethers, phosphate esters, siloxanes, dioxolanes (e.g., 1,3-dioxolane), N-alkylpyrrolidones, bis(trifluoromethanesulfonyl)imide, substituted forms of the foregoing, or blends thereof. Fluorinated derivatives of the foregoing are also useful as liquid electrolyte solvents.

[0064] In some embodiments, an electrolyte comprises an ester. The electrolyte may comprise a linear ester. In some embodiments, the electrolyte comprises an unfluorinated ester. In some embodiments, the electrolyte comprises an unfluorinated linear ester. In some embodiments, the electrolyte comprises a substituted ester (e.g., a halogenated ester, a fluorinated ester). In some embodiments, the electrolyte comprises a substituted linear ester (e.g., a halogenated linear ester, a fluorinated linear ester). For instance, in some embodiments, the electrolyte comprises a fluorinated ester such as 2,2,2, trifluoroethyl acetate, trifluoroethyl butyrate, and / or trifluoroethyl propionate. In some embodiments, the electrolyte may comprise an ester comprising an acetate, for example, methyl acetate, ethyl acetate, n-propyl acetate, z-propyl acetate, zz-butyl acetate, and / or i-butyl acetate. Other non-limiting examples of esters that may be included in the electrolyte are methyl propionate and / or methyl butyrate.

[0065] An electrolyte may comprise an ester comprising a carbonate (e.g., a carbonate ester, an organic carbonate). In some embodiments, an electrolyte comprises a linear carbonate. A linear carbonate, according to some embodiments, has the chemical structure (I)

[0066]

[0067] wherein R1and R2can be the same or different, and each is independently selected from unsubstituted, branched or unbranched aliphatic; substituted or unsubstituted, branched or unbranched haloaliphatic; or substituted or unsubstituted, branched or unbranched haloheteroaliphatic chains comprising between 1 and 10 carbon atoms (e.g., greater than or equal to 2, greater than or equal to 4, greater than or equal to 6, greater than or equal to 8 and / or less than or equal to 10, less than or equal to 8, less than or equal to 6, less than or equal to 4). For example, in some cases, R1comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. In some cases, R2comprises 1, 2, 3, 4, 5, 6, 7, 8,

[0068] #14755643vl9, or 10 carbon atoms. For example, the carbonate may be dimethyl carbonate (DMC), diethyl carbonate, or ethylmethyl carbonate (EMC).

[0069] In some embodiments, an electrolyte comprises an ester comprising a cyclic carbonate. In some embodiments, the electrolyte comprises an ester comprising a halogenated (e.g., fluorinated) cyclic carbonate. A cyclic carbonate, according to some embodiments, has the chemical structure (II)

[0070]

[0071] (II); wherein R3connects two oxygen atoms to form a heterocycle, and is selected from unsubstituted, unbranched aliphatic; substituted or unsubstituted, unbranched haloaliphatic; or substituted or unsubstituted, unbranched haloheteroaliphatic chains comprising between 1 and 10 carbon atoms (e.g., greater than or equal to 2, greater than or equal to 4, greater than or equal to 6, greater than or equal to 8 and / or less than or equal to 10, less than or equal to 8, less than or equal to 6, less than or equal to 4). For example, in some cases, R3comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. For example, the cyclic carbonate may be fluoroethylene carbonate (FEC).

[0072] According to some embodiments, an electrolyte comprises a combination of linear carbonates and cyclic carbonates. For example, in some such cases, the electrolyte may comprise DMC and FEC. In some cases, the electrolyte comprises EMC and FEC. Other combinations of linear and cyclic carbonates, as well as other solvents mentioned elsewhere herein (e.g., carbonates and sulfonamides), are contemplated with the use of electrochemical cells described herein.

[0073] In some embodiments, an electrolyte may comprise an ester in a variety of amounts. For example, in some embodiments, an ester may be present in an amount of greater than or equal to 10 wt%, greater than or equal to 12 wt%, greater than or equal to 14 wt%, greater than or equal to 16 wt%, greater than or equal to 18 wt%, greater than or equal to 20 wt%, greater than or equal to 22 wt%, greater than or equal to 24 wt%, greater than or equal to 26 wt%, greater than or equal to 28 wt%, greater than or equal to 28.2 wt%, greater than or equal to 28.4 wt%, greater than or equal to 28.6 wt%, greater

[0074] #14755643vlthan or equal to 28.8 wt%, greater than or equal to 29 wt%, greater than or equal to 29.2 wt%, greater than or equal to 29.4 wt%, greater than or equal to 29.6 wt%, greater than or equal to 29.8 wt%, greater than or equal to 30 wt%, greater than or equal to 30.2 wt%, greater than or equal to 30.4 wt%, greater than or equal to 30.6 wt%, greater than or equal to 30.8 wt%, greater than or equal to 31 wt%, greater than or equal to 31.2 wt%, greater than or equal to 31.4 wt%, greater than or equal to 31.6 wt%, greater than or equal to 31.7 wt%, greater than or equal to 31.8 wt%, or greater than or equal to 32 wt% of the electrolyte. According to some embodiments, an ester may be present in an amount of less than or equal to 34 wt%, less than or equal to 32 wt%, less than or equal to 31.8 wt%, less than or equal to 31.7 wt%, less than or equal to 31.6 wt%, less than or equal to 31.4 wt%, less than or equal to 31.2 wt%, less than or equal to 31 wt%, less than or equal to 30.8 wt%, less than or equal to 30.6 wt%, less than or equal to 30.4 wt%, less than or equal to 30.2 wt%, less than or equal to 30 wt%, less than or equal to 29.8 wt%, less than or equal to 29.6 wt%, less than or equal to 29.4 wt%, less than or equal to 29.2 wt%, less than or equal to 29 wt%, less than or equal to 28.8 wt%, less than or equal to 28.6 wt%, less than or equal to 28.4 wt%, less than or equal to 28.2 wt%, less than or equal to 28 wt%, less than or equal to 26 wt%, less than or equal to 24 wt%, less than or equal to 22 wt%, less than or equal to 20 wt%, less than or equal to 18 wt%, less than or equal to 16 wt%, less than or equal to 14 wt%, or less than or equal to 12 wt% of the electrolyte. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 10 wt% and less than or equal to 34 wt%, greater than or equal to 28 wt% and less than or equal to 32 wt%). Other ranges are also possible.

[0075] In some embodiments, wherein the electrolyte comprises multiple esters (e.g., FEC and EMC), each ester may independently be present in the electrolyte in an amount that corresponds to the foregoing ranges and / or all of the esters together may make up an amount of the electrolyte that corresponds to the foregoing ranges. In some such cases, the amounts of each ester may be equal to each other. In other such cases, the amounts of each ester may be different from each other.

[0076] In some embodiments, an electrolyte may comprise a relatively low total amount of fluorinated carbonates. In some embodiments, the total amount of fluorinated carbonates in an electrolyte is less than or equal to 50 wt%, less than or equal to 45 wt%, less than or equal to 30 wt%, less than or equal to 25 wt%, less than or equal to 20 wt%,

[0077] #14755643vlless than or equal to 15 wt%, less than or equal to 10 wt%, less than or equal to 5 wt%, less than or equal to 2 wt%, less than or equal to 1 wt%, less than or equal to 0.1 wt%, less than or equal to 0.01 wt%, or identically 0 wt% of the electrolyte. In some embodiments, the total amount of fluorinated carbonates in an electrolyte is greater than or equal to 0 wt%, greater than or equal to 0.01 wt%, greater than or equal to 0.1 wt%, greater than or equal to 1 wt%, greater than or equal to 2 wt%, greater than or equal to 5 wt%, greater than or equal to 10 wt%, greater than or equal to 15 wt%, greater than or equal to 20 wt%, greater than or equal to 25 wt%, greater than or equal to 30 wt%, greater than or equal to 35 wt%, greater than or equal to 40 wt%, or greater than or equal to 45 wt% of the electrolyte. Combinations of the above-referenced ranges are also possible (e.g., greater than or equal to 0 wt% and less than or equal to 50 wt%). Other ranges are also possible.

[0078] In some embodiments, an electrolyte comprises one or more ethers, such as one or more unfluorinated ethers and / or one or more fluorinated ethers.

[0079] Some unfluorinated ethers may be coordinating solvents. In such embodiments, the ether functional groups may coordinate ions present in the electrolyte. Without wishing to be bound by any particular theory, it is believed that some unfluorinated ethers may coordinate ions, including Li+ions, desirably well. It is also believed that some unfluorinated ethers may undesirably be relatively prone to oxidative decomposition because they have a relatively high HOMO energy and a C-H bonds adjacent to oxygen atoms. It is believed that this may be more pronounced at higher temperatures (e.g., those in excess of 72 °C) and / or high potentials (e.g., in excess of 4 vs. Li+ / Li). In some embodiments, electrolytes comprising both an unfluorinated ether and one or more further species described elsewhere herein (e.g., a sultone, LiBF4) may desirably exhibit the beneficial coordination of Li+ions associated with ethers while experiencing fewer or none of the above-noted drawbacks.

[0080] Some fluorinated ethers may be non-solvating diluents.

[0081] The electrolytes described herein may comprise a linear ether. In some embodiments, the electrolyte comprises a cyclic ether. In some embodiments, the electrolyte comprises a substituted or an unsubstituted ether. In some embodiments, the electrolyte comprises an unhalogenated and / or an unfluorinated ether (e.g., as a coordinating solvent as described above). In some embodiments, the electrolyte

[0082] #14755643vlcomprises a halogenated (e.g., fluorinated) ether (e.g., as a non-solvating diluent as described above). A linear ether, according to some embodiments, has the chemical structure (III)

[0083]

[0084] wherein R4and R5can be the same or different, and each is independently selected from unsubstituted, branched or unbranched aliphatic; substituted or unsubstituted, branched or unbranched haloaliphatic; or substituted or unsubstituted, branched or unbranched haloheteroaliphatic chains comprising between 1 and 10 carbon atoms (e.g., greater than or equal to 2, greater than or equal to 4, greater than or equal to 6, greater than or equal to 8 and / or less than or equal to 10, less than or equal to 8, less than or equal to 6, less than or equal to 4). For example, in some cases, R4comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. In some cases, R5comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. For example, the ether may be a fluorinated ether such as 1, 1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether (HFE), l,l,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE), a bis(2,2,2-trifluoroethyl)ether (BTFE), 2, 2, 3, 3, 4, 4,5,5-octafluoropentyl 1,1,2,2-tetrafluoroethyl ether, 2-(2,2,2-trifluoroethoxy)ethyl methyl ether, and / or l,2-(l,l,2,2-tetrafluoroethoxy)ethane. Non-limiting examples of suitable unfluorinated ethers include dimethoxyethane (DME), diethoxyethane (DEE), ethylene glycol ethyl methyl ether (EME), 1,3-dioxolane (DOL), and diethylene glycol dimethyl ether (diglyme).

[0085] In some embodiments, an electrolyte may comprise an ether in a variety of amounts. For example, in some embodiments, an ether may be present in an amount of greater than or equal to 10 wt%, greater than or equal to 12 wt%, greater than or equal to 14 wt%, greater than or equal to 16 wt%, greater than or equal to 18 wt%, greater than or equal to 20 wt%, greater than or equal to 22 wt%, greater than or equal to 24 wt%, greater than or equal to 26 wt%, greater than or equal to 28 wt%, greater than or equal to 28.2 wt%, greater than or equal to 28.4 wt%, greater than or equal to 28.6 wt%, greater than or equal to 28.8 wt%, greater than or equal to 29 wt%, greater than or equal to 29.2 wt%, greater than or equal to 29.4 wt%, greater than or equal to 29.6 wt%, greater than or equal to 29.8 wt%, greater than or equal to 30 wt%, greater than or equal to 30.2 wt%, greater than or equal to 30.4 wt%, greater than or equal to 30.6 wt%, greater than or

[0086] #14755643vlequal to 30.8 wt%, greater than or equal to 31 wt%, greater than or equal to 31.2 wt%, greater than or equal to 31.4 wt%, greater than or equal to 31.6 wt%, greater than or equal to 31.7 wt%, greater than or equal to 31.8 wt%, greater than or equal to 32 wt%, greater than or equal to 33 wt%, or greater than or equal to 34 wt% of the electrolyte. According to some embodiments, an ether may be present in an amount of less than or equal to 35 wt%, less than or equal to 34 wt%, less than or equal to 33 wt%, less than or equal to 32 wt%, less than or equal to 31.8 wt%, less than or equal to 31.7 wt%, less than or equal to 31.6 wt%, less than or equal to 31.4 wt%, less than or equal to 31.2 wt%, less than or equal to 31 wt%, less than or equal to 30.8 wt%, less than or equal to 30.6 wt%, less than or equal to 30.4 wt%, less than or equal to 30.2 wt%, less than or equal to 30 wt%, less than or equal to 29.8 wt%, less than or equal to 29.6 wt%, less than or equal to 29.4 wt%, less than or equal to 29.2 wt%, less than or equal to 29 wt%, less than or equal to 28.8 wt%, less than or equal to 28.6 wt%, less than or equal to 28.4 wt%, less than or equal to 28.2 wt%, less than or equal to 28 wt%, less than or equal to 26 wt%, less than or equal to 24 wt%, less than or equal to 22 wt%, less than or equal to 20 wt%, less than or equal to 18 wt%, less than or equal to 16 wt%, less than or equal to 14 wt%, or less than or equal to 12 wt% of the electrolyte. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 10 wt% and less than or equal to 35 wt%, greater than or equal to 20 wt% and less than or equal to 34 wt%, greater than or equal to 28 wt% and less than or equal to 30 wt%). Other ranges are also possible.

[0087] In some embodiments, wherein the electrolyte comprises multiple ethers (e.g., fluorinated ethers), each ether may independently be present in the electrolyte in an amount that corresponds to the foregoing ranges and / or all of the ethers together may make up an amount of the electrolyte that corresponds to the foregoing ranges. In some such cases, the amounts of each ether may be equal to each other. In other such cases, the amounts of each ether may be different from each other.

[0088] In some embodiments, an electrolyte may comprise an unfluorinated ether in a variety of amounts. For example, in some embodiments, an unfluorinated ether may be present in an amount of greater than or equal to 10 wt%, greater than or equal to 12 wt%, greater than or equal to 14 wt%, greater than or equal to 16 wt%, greater than or equal to 18 wt%, greater than or equal to 20 wt%, greater than or equal to 22 wt%, greater than or equal to 24 wt%, greater than or equal to 26 wt%, greater than or equal to 28 wt%,

[0089] #14755643vlgreater than or equal to 28.2 wt%, greater than or equal to 28.4 wt%, greater than or equal to 28.6 wt%, greater than or equal to 28.8 wt%, greater than or equal to 29 wt%, greater than or equal to 29.2 wt%, greater than or equal to 29.4 wt%, greater than or equal to 29.6 wt%, greater than or equal to 29.8 wt%, greater than or equal to 30 wt%, greater than or equal to 30.2 wt%, greater than or equal to 30.4 wt%, greater than or equal to 30.6 wt%, greater than or equal to 30.8 wt%, greater than or equal to 31 wt%, greater than or equal to 31.2 wt%, greater than or equal to 31.4 wt%, greater than or equal to 31.6 wt%, greater than or equal to 31.7 wt%, greater than or equal to 31.8 wt%, greater than or equal to 32 wt%, greater than or equal to 33 wt%, or greater than or equal to 34 wt% of the electrolyte. According to some embodiments, an unfluorinated ether may be present in an amount of less than or equal to 35 wt%, less than or equal to 34 wt%, less than or equal to 33 wt%, less than or equal to 32 wt%, less than or equal to 31.8 wt%, less than or equal to 31.7 wt%, less than or equal to 31.6 wt%, less than or equal to 31.4 wt%, less than or equal to 31.2 wt%, less than or equal to 31 wt%, less than or equal to 30.8 wt%, less than or equal to 30.6 wt%, less than or equal to 30.4 wt%, less than or equal to 30.2 wt%, less than or equal to 30 wt%, less than or equal to 29.8 wt%, less than or equal to 29.6 wt%, less than or equal to 29.4 wt%, less than or equal to 29.2 wt%, less than or equal to 29 wt%, less than or equal to 28.8 wt%, less than or equal to 28.6 wt%, less than or equal to 28.4 wt%, less than or equal to 28.2 wt%, less than or equal to 28 wt%, less than or equal to 26 wt%, less than or equal to 24 wt%, less than or equal to 22 wt%, less than or equal to 20 wt%, less than or equal to 18 wt%, less than or equal to 16 wt%, less than or equal to 14 wt%, or less than or equal to 12 wt% of the electrolyte. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 10 wt% and less than or equal to 35 wt%, greater than or equal to 20 wt% and less than or equal to 34 wt%, greater than or equal to 28 wt% and less than or equal to 30 wt%). Other ranges are also possible.

[0090] In some embodiments, wherein the electrolyte comprises multiple unfluorinated ethers, each unfluorinated ether may independently be present in the electrolyte in an amount that corresponds to the foregoing ranges and / or all of the unfluorinated ethers together may make up an amount of the electrolyte that corresponds to the foregoing ranges. In some such cases, the amounts of each unfluorinated ether may be equal to

[0091] #14755643vleach other. In other such cases, the amounts of each unfluorinated ether may be different from each other.

[0092] In some embodiments, an electrolyte may comprise dimethoxyethane in a variety of amounts. For example, in some embodiments, dimethoxyethane may be present in an amount of greater than or equal to 0 wt%, greater than or equal to 5 wt%, greater than or equal to 10 wt%, greater than or equal to 15 wt%, or greater than or equal to 20 wt% of the electrolyte. In some embodiments, dimethoxyethane may be present in an amount of less than or equal to 25 wt%, less than or equal to 20 wt%, less than or equal to 15 wt%, less than or equal to 10 wt%, or less than or equal to 5 wt% of the electrolyte.

[0093] Combinations of the above-referenced ranges are also possible (e.g., greater than or equal to 0 wt% and less than or equal to 25 wt%). Other ranges are also possible.

[0094] In some embodiments, an electrolyte may comprise diethoxyethane in a variety of amounts. For example, in some embodiments, diethoxyethane may be present in an amount of greater than or equal to 0 wt%, greater than or equal to 5 wt%, greater than or equal to 10 wt%, greater than or equal to 15 wt%, or greater than or equal to 20 wt% of the electrolyte. In some embodiments, diethoxyethane may be present in an amount of less than or equal to 25 wt%, less than or equal to 20 wt%, less than or equal to 15 wt%, less than or equal to 10 wt%, or less than or equal to 5 wt% of the electrolyte.

[0095] Combinations of the above-referenced ranges are also possible (e.g., greater than or equal to 0 wt% and less than or equal to 25 wt%). Other ranges are also possible.

[0096] In some embodiments, an electrolyte may comprise a fluorinated ether in a variety of amounts. For example, in some embodiments, a fluorinated ether may be present in an amount of greater than or equal to 30 wt%, greater than or equal to 35 wt%, greater than or equal to 40 wt%, greater than or equal to 45 wt%, greater than or equal to 50 wt%, greater than or equal to 55 wt%, greater than or equal to 60 wt%, or greater than or equal to 65 wt% of the electrolyte. In some embodiments, a fluorinated ether may be present in an amount of less than or equal to 70 wt%, less than or equal to 65 wt%, less than or equal to 60 wt%, less than or equal to 55 wt%, less than or equal to 50 wt%, less than or equal to 45 wt%, less than or equal to 40 wt%, or less than or equal to 35 wt% of the electrolyte. Combinations of the above-referenced ranges are also possible (e.g., greater than or equal to 30 wt% and less than or equal to 70 wt%). Other ranges are also possible.

[0097] #14755643vlIn some embodiments, wherein the electrolyte comprises multiple fluorinated ethers, each fluorinated ether may independently be present in the electrolyte in an amount that corresponds to the foregoing ranges and / or all of the fluorinated ethers together may make up an amount of the electrolyte that corresponds to the foregoing ranges. In some such cases, the amounts of each fluorinated ether may be equal to each other. In other such cases, the amounts of each fluorinated ether may be different from each other.

[0098] In some embodiments, an electrolyte may comprise 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether in a variety of amounts. For example, in some embodiments, l,l,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether may be present in an amount of greater than or equal to 0 wt%, greater than or equal to 5 wt%, greater than or equal to 10 wt%, greater than or equal to 15 wt%, greater than or equal to 20 wt%, greater than or equal to 25 wt%, greater than or equal to 30 wt%, greater than or equal to 35 wt%, greater than or equal to 40 wt%, greater than or equal to 45 wt%, greater than or equal to 50 wt%, greater than or equal to 55 wt%, greater than or equal to 60 wt%, or greater than or equal to 65 wt% of the electrolyte. In some embodiments, 1, 1,2,2-tetrafhioroethyl-2,2,3,3-tetrafluoropropylether may be present in an amount of less than or equal to 70 wt%, less than or equal to 65 wt%, less than or equal to 60 wt%, less than or equal to 55 wt%, less than or equal to 50 wt%, less than or equal to 45 wt%, less than or equal to 40 wt%, less than or equal to 35 wt%, less than or equal to 30 wt%, less than or equal to 25 wt%, less than or equal to 20 wt%, less than or equal to 15 wt%, less than or equal to 10 wt%, or less than or equal to 5 wt% of the electrolyte. Combinations of the above-referenced ranges are also possible (e.g., greater than or equal to 0 wt% and less than or equal to 70 wt%). Other ranges are also possible.

[0099] In some embodiments, an electrolyte may comprise 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethylether in a variety of amounts. For example, in some embodiments, 11,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethylether may be present in an amount of greater than or equal to 0 wt%, greater than or equal to 5 wt%, greater than or equal to 10 wt%, or greater than or equal to 15 wt% of the electrolyte. In some embodiments, 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethylether may be present in an amount of less than or equal to 20 wt%, less than or equal to 15 wt%, less than or equal to 10 wt%, or less than or equal to 5 wt% of the electrolyte. Combinations of the above-referenced ranges are

[0100] #14755643vlalso possible (e.g., greater than or equal to 0 wt% and less than or equal to 20 wt%). Other ranges are also possible.

[0101] In some embodiments, an electrolyte may comprise bis(2,2,2-trifluoroethyl)ether in a variety of amounts. For example, in some embodiments, bis(2,2,2-trifluoroethyl)ether may be present in an amount of greater than or equal to 0 wt%, greater than or equal to 5 wt%, greater than or equal to 10 wt%, or greater than or equal to 15 wt% of the electrolyte. In some embodiments, bis(2,2,2-trifluoroethyl)ether may be present in an amount of less than or equal to 20 wt%, less than or equal to 15 wt%, less than or equal to 10 wt%, or less than or equal to 5 wt% of the electrolyte. Combinations of the above -referenced ranges are also possible (e.g., greater than or equal to 0 wt% and less than or equal to 20 wt%). Other ranges are also possible.

[0102] In some embodiments, an electrolyte may comprise none, either, or both of 1.1.2.2-tetrafluoroethyl 2,2,2-trifluoroethylether and bis(2,2,2-trifluoroethyl)ether, and these two solvents may together make up a variety of suitable amounts of the electrolyte. For example, in some embodiments, the combined amount of 1,1,2,2-tetrafluoroethyl 2.2.2-trifluoroethylether and bis(2,2,2-trifluoroethyl)ether is greater than or equal to 0 wt%, greater than or equal to 5 wt%, greater than or equal to 10 wt%, or greater than or equal to 15 wt% of the electrolyte. In some embodiments, the combined amount of 1.1.2.2-tetrafluoroethyl 2,2,2-trifluoroethylether and bis(2,2,2-trifluoroethyl)ether is less than or equal to 20 wt%, less than or equal to 15 wt%, less than or equal to 10 wt%, or less than or equal to 5 wt% of the electrolyte. Combinations of the above-referenced ranges are also possible (e.g., greater than or equal to 0 wt% and less than or equal to 20 wt%). Other ranges are also possible.

[0103] An electrolyte in the electrochemical cell may comprise a sulfonamide. In accordance with some embodiments, a sulfonamide may have a structure according to structure (IV):

[0104]

[0105] wherein R6, R7, and R8can be the same or different, and each is independently selected from unsubstituted, branched or unbranched aliphatic; substituted or

[0106] #14755643vlunsubstituted, branched or unbranched haloaliphatic; a halogen; or substituted or unsubstituted, branched or unbranched haloheteroaliphatic chains comprising between 1 and 10 carbon atoms (e.g., greater than or equal to 2, greater than or equal to 4, greater than or equal to 6, greater than or equal to 8 and / or less than or equal to 10, less than or equal to 8, less than or equal to 6, less than or equal to 4). For example, in some cases, R6comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. In some cases, R7comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. In some cases, R8comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. In some embodiments, the sulfonamide comprises a N,N-sulfonamoyl fluoride, where the R6is fluorine (e.g., fluoride) and the R7and R8groups are each independently branched or unbranched alkyl groups having 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. For example, the sulfonamide may be N,N-dimethylsulfamoyl fluoride and / or N,N-diethylsulfamoyl fluoride.

[0107] In some embodiments, an electrolyte may comprise a sulfonamide in a variety of amounts. For example, in some embodiments, a sulfonamide may be present in an amount of greater than or equal to 40 wt%, greater than or equal to 41 wt%, greater than or equal to 42 wt%, greater than or equal to 43 wt%, greater than or equal to 44 wt%, greater than or equal to 44.3 wt%, greater than or equal to 44.6 wt%, greater than or equal to 44.9 wt%, greater than or equal to 45 wt%, greater than or equal to 45.3 wt%, greater than or equal to 45.6 wt%, greater than or equal to 45.9 wt%, greater than or equal to 46 wt%, greater than or equal to 46.3 wt%, greater than or equal to 46.6 wt%, greater than or equal to 46.9 wt%, greater than or equal to 47 wt%, greater than or equal to 48 wt%, or greater than or equal to 49 wt% of the electrolyte. According to some embodiments, a sulfonamide may be present in an amount of less than or equal to 50 wt%, less than or equal to 49 wt%, less than or equal to 48 wt%, less than or equal to 47 wt%, less than or equal to 46.9 wt%, less than or equal to 46.6 wt%, less than or equal to 46.3 wt%, less than or equal to 46 wt%, less than or equal to 45.9 wt%, less than or equal to 45.6 wt%, less than or equal to 45.3 wt%, less than or equal to 45 wt%, less than or equal to 44.9 wt%, less than or equal to 44.6 wt%, less than or equal to 44.3 wt%, less than or equal to 44 wt%, less than or equal to 43 wt%, less than or equal to 42 wt%, or less than or equal to 41 wt%. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 40 wt% and less than or equal to 50 wt%). Other ranges are also possible.

[0108] #14755643vlIn some embodiments, wherein the electrolyte comprises multiple sulfonamides, each sulfonamide may independently be present in the electrolyte in an amount that corresponds to the foregoing ranges and / or all of the sulfonamides together may make up an amount of the electrolyte that corresponds to the foregoing ranges. In some such cases, the amounts of each sulfonamide may be equal to each other. In other such cases, the amounts of each sulfonamide may be different from each other.

[0109] An electrolyte in the electrochemical cell may comprise a sultone. A sultone is a cyclic sulfonate ester having a structure (V):

[0110] O.

[0111] R X9- O (V); Wherein R9is selected from unsubstituted, unbranched aliphatic; substituted or unsubstituted, unbranched haloaliphatic; or substituted or unsubstituted, unbranched haloheteroaliphatic chains comprising between 1 and 10 carbon atoms (e.g., greater than or equal to 2, greater than or equal to 4, greater than or equal to 6, greater than or equal to 8 and / or less than or equal to 10, less than or equal to 8, less than or equal to 6, less than or equal to 4). In some cases, the group connecting the sulfur and oxygen of the sulfonate group in the heterocycle of the sultone may comprise 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. For example, the sultone may comprise 1,3,2 dioxathiolane 2,2 dioxide (DTD), 1,5,2,4-dioxadithiane 2,2,4,5-tetraoxide (MMDS), 1,4-butane sultone (BS), 1,3-propane sultone, and / or prop-l-ene-l,3-sultone (PES).

[0112] In some embodiments, an electrolyte may comprise a sultone in any of a variety of amounts. In some embodiments, the sultone may be present in the electrolyte in an amount of greater than or equal to 0.1 wt%, greater than or equal to 0.5 wt%, greater than or equal to 1 wt%, greater than or equal to 2 wt%, greater than or equal to 3 wt%, greater than or equal to 4 wt%, greater than or equal to 5 wt%, greater than or equal to 6 wt%, greater than or equal to 7 wt%, greater than or equal to 8 wt%, or greater than or equal to 9 wt% of the electrolyte. In some embodiments, the sultone may be present in the electrolyte in an amount of less than or equal to 10 wt%, less than or equal to 9 wt%, less than or equal to 8 wt%, less than or equal to 7 wt%, less than or equal to 6 wt%, less than or equal to 5 wt%, less than or equal to 4 wt%, less than or equal to 3 wt%, less than or equal to 2 wt%, less than or equal to 1 wt%, or less than or equal to 0.5 wt% of the

[0113] #14755643vlelectrolyte. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.1 wt% and less than or equal to 15 wt%, greater than or equal to 0.1 wt% and less than or equal to 2 wt%, or greater than or equal to 0.5 wt% and less than or equal to 5 wt%). Other ranges are also possible.

[0114] In some embodiments, wherein the electrolyte comprises multiple sultones, each sultone may independently be present in the electrolyte in an amount that corresponds to the foregoing ranges and / or all of the sultones together may make up an amount of the electrolyte that corresponds to the foregoing ranges. In some such cases, the amounts of each sultone may be equal to each other. In other such cases, the amounts of each sultone may be different from each other. In some embodiments, the sultone is included in the electrolyte in a relatively small amount, e.g., less than or equal to 5 wt%, less than or equal to 4 wt%, less than or equal to 3 wt% of the electrolyte, or so forth as described in the foregoing ranges.

[0115] In some embodiments, an electrolyte may comprise prop-l-ene-l,3-sultone in any of a variety of amounts. In some embodiments, prop-l-ene-l,3-sultone may be present in the electrolyte in an amount of greater than or equal to 0.1 wt%, greater than or equal to 0.5 wt%, or greater than or equal to 1 wt% of the electrolyte. In some embodiments, prop-l-ene-l,3-sultone may be present in the electrolyte in an amount of less than or equal to \ 2 wt%, less than or equal to 1 wt%, or less than or equal to 0.5 wt% of the electrolyte. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.1 wt% and less than or equal to 2 wt%). Other ranges are also possible.

[0116] In some embodiments, an electrolyte comprises methylene methanedisulfonate. In some embodiments, the methylene methanedisulfonate makes up greater than or equal to 0 wt%, greater than or equal to 0.5 wt%, greater than or equal to 1 wt%, or greater than or equal to 1.5 wt% of the electrolyte. In some embodiments, the methylene methanedisulfonate makes up less than or equal to 2 wt%, less than or equal to 1.5 wt%, less than or equal to 1 wt%, or less than or equal to 0.5 wt% of the electrolyte.

[0117] Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0 wt% and less than or equal to 2 wt%). Other ranges are also possible.

[0118] In some embodiments, one or more of the species described herein may be considered to be an additive. Non-limiting examples of species that may be considered to

[0119] #14755643vlbe additives include 1,3 propane sultone, 1,4-butane sultone, 1,3,2 dioxathiolane 2,2 dioxide, 1,5,2,4-dioxadithiane 2,2,4,5-tetraoxide, andLiBF4.

[0120] Additives may make up a variety of suitable amounts of the electrolytes described herein. In some embodiments, additives make up greater than or equal to 0.5 wt%, greater than or equal to 1 wt%, greater than or equal to 1.5 wt%, greater than or equal to 2 wt%, greater than or equal to 2.5 wt%, greater than or equal to 3 wt%, greater than or equal to 3.5 wt%, greater than or equal to 4 wt%, or greater than or equal to 4.5 wt% of the electrolyte. In some embodiments, additives make up less than or equal to 5 wt%, less than or equal to 4.5 wt%, less than or equal to 4 wt%, less than or equal to 3.5 wt%, less than or equal to 3 wt%, less than or equal to 2.5 wt%, less than or equal to 2 wt%, less than or equal to 1.5 wt%, or less than or equal to 1 wt% of the electrolyte. Combinations of the above-referenced ranges are also possible (e.g., greater than or equal to 0.5 wt% and less than or equal to 5 wt%). Other ranges are also possible.

[0121] In some embodiments, an electrolyte comprises one or more fluorinated cyclic carbonates and one or more fluorinated ethers. In some embodiments, the one or more fluorinated cyclic carbonates and one or more fluorinated ethers together make up greater than or equal to 20 wt%, greater than or equal to 30 wt%, greater than or equal to 40 wt%, greater than or equal to 50 wt%, greater than or equal to 60 wt%, greater than or equal to 70 wt%, or greater than or equal to 74 wt% of the electrolyte. In some embodiments, the one or more fluorinated cyclic carbonates and one or more fluorinated ethers together make up less than or equal to 80 wt%, less than or equal to 74 wt%, less than or equal to 70 wt%, less than or equal to 60 wt%, less than or equal to 50 wt%, less than or equal to 40 wt%, or less than or equal to 30 wt% of the electrolyte. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 20 wt%, and less than or equal to 80 wt%). Other ranges are also possible. In some embodiments, a total amount of the fluorinated cyclic carbonates and fluorinated ethers in the electrolyte is in one or more of the above -referenced ranges.

[0122] In some embodiments, an electrolyte comprises one or more fluorinated cyclic carbonates and one or more fluorinated sulfonamides. In some embodiments, the one or more fluorinated cyclic carbonates and one or more fluorinated sulfonamides together make up greater than or equal to 20 wt%, greater than or equal to 30 wt%, greater than or equal to 40 wt%, greater than or equal to 50 wt%, greater than or equal to 60 wt%,

[0123] #14755643vlgreater than or equal to 70 wt%, or greater than or equal to 74 wt% of the electrolyte. In some embodiments, the one or more fluorinated cyclic carbonates and one or more fluorinated sulfonamides together make up less than or equal to 80 wt%, less than or equal to 74 wt%, less than or equal to 70 wt%, less than or equal to 60 wt%, less than or equal to 50 wt%, less than or equal to 40 wt%, or less than or equal to 30 wt% of the electrolyte. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 20 wt%, and less than or equal to 80 wt%). Other ranges are also possible. In some embodiments, a total amount of the fluorinated cyclic carbonates and fluorinated sulfonamides in the electrolyte is in one or more of the above -referenced ranges.

[0124] In some embodiments, an electrolyte comprises one or more fluorinated cyclic carbonate and one or more fluorinated linear ester. In some embodiments, the one or more fluorinated cyclic carbonates and one or more fluorinated linear esters together make up greater than or equal to 20 wt%, greater than or equal to 30 wt%, greater than or equal to 40 wt%, greater than or equal to 50 wt%, greater than or equal to 60 wt%, greater than or equal to 70 wt%, or greater than or equal to 74 wt% of the electrolyte. In some embodiments, the one or more fluorinated cyclic carbonates and one or more fluorinated linear esters together make up less than or equal to 80 wt% of the electrolyte, less than or equal to 74 wt%, less than or equal to 70 wt%, less than or equal to 60 wt%, less than or equal to 50 wt%, less than or equal to 40 wt%, or less than or equal to 30 wt% of the electrolyte. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 20 wt%, and less than or equal to 80 wt%). Other ranges are also possible. In some embodiments, a total amount of the fluorinated cyclic carbonates and fluorinated linear esters in the electrolyte is in one or more of the above-referenced ranges.

[0125] In some embodiments, an electrolyte comprises one or more fluorinated cyclic carbonates, one or more unfluorinated linear esters, and one or more fluorinated ethers. In some embodiments, a weight ratio of the one or more fluorinated cyclic carbonates to a combined weight of the one or more unfluorinated linear esters and the one or more fluorinated ethers is greater than or equal to 0.25, greater than or equal to 0.3, greater than or equal to 0.35, greater than or equal to 0.4, greater than or equal to 0.45, greater than or equal to 0.5, greater than or equal to 0.55, greater than or equal to 0.6, greater than or equal to 0.65, greater than or equal to 0.7, greater than or equal to 0.75, greater

[0126] #14755643vlthan or equal to 0.8, greater than or equal to 0.85, greater than or equal to 0.9, or greater than or equal to 0.95. In some embodiments, a weight ratio of the one or more fluorinated cyclic carbonates to a combined weight of the one or more unfluorinated linear esters and the one or more fluorinated ethers is less than or equal to 1, less than or equal to 0.95, less than or equal to 0.9, less than or equal to 0.85, less than or equal to 0.8, less than or equal to 0.75, less than or equal to 0.7, less than or equal to 0.65, less than or equal to 0.6, less than or equal to 0.55, less than or equal to 0.5, less than or equal to 0.45, less than or equal to 0.4, less than or equal to 0.35, or less than or equal to 0.3. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.25 and less than or equal to 1). Other ranges are also possible. In some embodiments, a total amount of the fluorinated cyclic carbonates and unfluorinated linear esters in the electrolyte is in one or more of the above-referenced ranges.

[0127] In some embodiments, an electrolyte comprises one or more unfluorinated linear esters and one or more fluorinated ethers. According to some embodiments, a weight ratio of the one or more unfluorinated linear esters to the one or more fluorinated ethers is greater than or equal to 0.25, greater than or equal to 0.3, greater than or equal to 0.35, greater than or equal to 0.4, greater than or equal to 0.45, greater than or equal to 0.5, greater than or equal to 0.55, greater than or equal to 0.6, greater than or equal to 0.65, greater than or equal to 0.7, greater than or equal to 0.75, greater than or equal to 0.8, greater than or equal to 0.85, greater than or equal to 0.9, greater than or equal to 0.95, greater than or equal to 1, greater than or equal to 1.1, greater than or equal to 1.2, greater than or equal to 1.3, greater than or equal to 1.4, greater than or equal to 1.5, greater than or equal to 1.6, greater than or equal to 1.7, greater than or equal to 1.8, greater than or equal to 1.9, greater than or equal to 2, greater than or equal to 2.1, greater than or equal to 2.2, greater than or equal to 2.3, greater than or equal to 2.4, greater than or equal to 2.5, greater than or equal to 2.6, greater than or equal to 2.7, greater than or equal to 2.8, greater than or equal to 2.9, greater than or equal to 3, greater than or equal to 3.1, greater than or equal to 3.2, greater than or equal to 3.3, greater than or equal to 3.4, greater than or equal to 3.5, greater than or equal to 3.6, greater than or equal to 3.7, greater than or equal to 3.8, or greater than or equal to 3.9. In some embodiments, a weight ratio of the one or more unfluorinated linear esters to the one or more fluorinated ethers is less than or equal to 4, less than or equal to 3.9, less

[0128] #14755643vlthan or equal to 3.8, less than or equal to 3.7, less than or equal to 3.6, less than or equal to 3.5, less than or equal to 3.4, less than or equal to 3.3, less than or equal to 3.2, less than or equal to 3.1, less than or equal to 3, less than or equal to 2.9, less than or equal to 2.8, less than or equal to 2.7, less than or equal to 2.6, less than or equal to 2.5, less than or equal to 2.4, less than or equal to 2.3, less than or equal to 2.2, less than or equal to 2.1, less than or equal to 2, less than or equal to 1.9, less than or equal to 1.8, less than or equal to 1.7, less than or equal to 1.6, less than or equal to 1.5, less than or equal to 1.4, less than or equal to 1.3, less than or equal to 1.2, less than or equal to 1.1, less than or equal to 1, less than or equal to 0.95, less than or equal to 0.9, less than or equal to 0.85, less than or equal to 0.8, less than or equal to 0.75, less than or equal to 0.7, less than or equal to 0.65, less than or equal to 0.6, less than or equal to 0.55, less than or equal to 0.5, less than or equal to 0.45, less than or equal to 0.4, less than or equal to 0.35, or less than or equal to 0.3. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.25 and less than or equal to 4). Other ranges are also possible. In some embodiments, a weight ratio of all of the unfluorinated linear esters in the electrolyte to all of the fluorinated ethers in the electrolyte is in one or more of the above -referenced ranges.

[0129] In some embodiments, an electrolyte comprises one or more unfluorinated linear esters and one or more fluorinated linear esters. According to some embodiments, a weight ratio of the one or more unfluorinated linear esters to the one or more fluorinated linear esters is greater than or equal to 0.25, greater than or equal to 0.3, greater than or equal to 0.35, greater than or equal to 0.4, greater than or equal to 0.45, greater than or equal to 0.5, greater than or equal to 0.55, greater than or equal to 0.6, greater than or equal to 0.65, greater than or equal to 0.7, greater than or equal to 0.75, greater than or equal to 0.8, greater than or equal to 0.85, greater than or equal to 0.9, greater than or equal to 0.95, greater than or equal to 1, greater than or equal to 1.1, greater than or equal to 1.2, greater than or equal to 1.3, greater than or equal to 1.4, greater than or equal to 1.5, greater than or equal to 1.6, greater than or equal to 1.7, greater than or equal to 1.8, greater than or equal to 1.9, greater than or equal to 2, greater than or equal to 2.1, greater than or equal to 2.2, greater than or equal to 2.3, greater than or equal to 2.4, greater than or equal to 2.5, greater than or equal to 2.6, greater than or equal to 2.7, greater than or equal to 2.8, greater than or equal to 2.9, greater than or equal to 3,

[0130] #14755643vlgreater than or equal to 3.1, greater than or equal to 3.2, greater than or equal to 3.3, greater than or equal to 3.4, greater than or equal to 3.5, greater than or equal to 3.6, greater than or equal to 3.7, greater than or equal to 3.8, or greater than or equal to 3.9. In some embodiments, a weight ratio of the one or more unfluorinated linear esters to the one or more fluorinated linear esters is less than or equal to 4, less than or equal to 3.9, less than or equal to 3.8, less than or equal to 3.7, less than or equal to 3.6, less than or equal to 3.5, less than or equal to 3.4, less than or equal to 3.3, less than or equal to 3.2, less than or equal to 3.1, less than or equal to 3, less than or equal to 2.9, less than or equal to 2.8, less than or equal to 2.7, less than or equal to 2.6, less than or equal to 2.5, less than or equal to 2.4, less than or equal to 2.3, less than or equal to 2.2, less than or equal to 2.1, less than or equal to 2, less than or equal to 1.9, less than or equal to 1.8, less than or equal to 1.7, less than or equal to 1.6, less than or equal to 1.5, less than or equal to 1.4, less than or equal to 1.3, less than or equal to 1.2, less than or equal to 1.1, less than or equal to 1, less than or equal to 0.95, less than or equal to 0.9, less than or equal to 0.85, less than or equal to 0.8, less than or equal to 0.75, less than or equal to 0.7, less than or equal to 0.65, less than or equal to 0.6, less than or equal to 0.55, less than or equal to 0.5, less than or equal to 0.45, less than or equal to 0.4, less than or equal to 0.35, or less than or equal to 0.3. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.25 and less than or equal to 4). Other ranges are also possible. In some embodiments, a weight ratio of all of the unfluorinated linear esters in the electrolyte to all of the fluorinated linear esters in the electrolyte is in one or more of the above-referenced ranges.

[0131] In some embodiments, an electrolyte comprises one or more fluorinated cyclic carbonates, one or more unfluorinated linear esters, and one or more fluorinated sulfonamides. According to some embodiments, a weight ratio of the one or more fluorinated cyclic carbonates to the combined weight of the one or more unfluorinated linear esters and the one or more fluorinated sulfonamides is greater than or equal to 0.25, greater than or equal to 0.3, greater than or equal to 0.35, greater than or equal to 0.4, greater than or equal to 0.45, greater than or equal to 0.5, greater than or equal to 0.55, greater than or equal to 0.6, greater than or equal to 0.65, greater than or equal to 0.7, greater than or equal to 0.75, greater than or equal to 0.8, greater than or equal to 0.85, greater than or equal to 0.9, or greater than or equal to 0.95. In some embodiments,

[0132] #14755643vla weight ratio of the one or more fluorinated cyclic carbonates to the combined weight of the one or more unfluorinated linear esters and the one or more fluorinated sulfonamides is less than or equal to 1, less than or equal to 0.95, less than or equal to 0.9, less than or equal to 0.85, less than or equal to 0.8, less than or equal to 0.75, less than or equal to 0.7, less than or equal to 0.65, less than or equal to 0.6, less than or equal to 0.55, less than or equal to 0.5, less than or equal to 0.45, less than or equal to 0.4, less than or equal to 0.35, or less than or equal to 0.3. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.25 and less than or equal to 1). Other ranges are also possible. In some embodiments, a weight ratio of all of the fluorinated cyclic carbonates in the electrolyte to the combined weight of all of the unfluorinated linear esters and all of the fluorinated sulfonamides in the electrolyte is in one or more of the abovereferenced ranges.

[0133] In some embodiments, an electrolyte comprises one or more unfluorinated linear esters and one or more fluorinated sulfonamides (e.g., one or more N, N di-alkyl sulfamoyl fluorides). According to some embodiments, a weight ratio of the one or more unfluorinated linear esters to the one or more fluorinated sulfonamides is greater than or equal to 0.25, greater than or equal to 0.3, greater than or equal to 0.35, greater than or equal to 0.4, greater than or equal to 0.45, greater than or equal to 0.5, greater than or equal to 0.55, greater than or equal to 0.6, greater than or equal to 0.65, greater than or equal to 0.7, greater than or equal to 0.75, greater than or equal to 0.8, greater than or equal to 0.85, greater than or equal to 0.9, greater than or equal to 0.95, greater than or equal to 1, greater than or equal to 1.1, greater than or equal to 1.2, greater than or equal to 1.3, greater than or equal to 1.4, greater than or equal to 1.5, greater than or equal to 1.6, greater than or equal to 1.7, greater than or equal to 1.8, greater than or equal to 1.9, greater than or equal to 2, greater than or equal to 2.1, greater than or equal to 2.2, greater than or equal to 2.3, greater than or equal to 2.4, greater than or equal to 2.5, greater than or equal to 2.6, greater than or equal to 2.7, greater than or equal to 2.8, greater than or equal to 2.9, greater than or equal to 3, greater than or equal to 3.1, greater than or equal to 3.2, greater than or equal to 3.3, greater than or equal to 3.4, greater than or equal to 3.5, greater than or equal to 3.6, greater than or equal to 3.7, greater than or equal to 3.8, or greater than or equal to 3.9. In some embodiments, a weight ratio of the one or more unfluorinated linear esters to the one or more fluorinated

[0134] #14755643vlsulfonamides is less than or equal to 4, less than or equal to 3.9, less than or equal to 3.8, less than or equal to 3.7, less than or equal to 3.6, less than or equal to 3.5, less than or equal to 3.4, less than or equal to 3.3, less than or equal to 3.2, less than or equal to 3.1, less than or equal to 3, less than or equal to 2.9, less than or equal to 2.8, less than or equal to 2.7, less than or equal to 2.6, less than or equal to 2.5, less than or equal to 2.4, less than or equal to 2.3, less than or equal to 2.2, less than or equal to 2.1, less than or equal to 2, less than or equal to 1.9, less than or equal to 1.8, less than or equal to 1.7, less than or equal to 1.6, less than or equal to 1.5, less than or equal to 1.4, less than or equal to 1.3, less than or equal to 1.2, less than or equal to 1.1, less than or equal to 1, less than or equal to 0.95, less than or equal to 0.9, less than or equal to 0.85, less than or equal to 0.8, less than or equal to 0.75, less than or equal to 0.7, less than or equal to 0.65, less than or equal to 0.6, less than or equal to 0.55, less than or equal to 0.5, less than or equal to 0.45, less than or equal to 0.4, less than or equal to 0.35, or less than or equal to 0.3. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.25 and less than or equal to 4). Other ranges are also possible. In some embodiments, a weight ratio of all of the unfluorinated linear esters in the electrolyte to all of the fluorinated sulfonamides in the electrolyte is in one or more of the abovereferenced ranges. In some embodiments, an electrolyte comprises one or more fluorinated cyclic carbonates, one or more unfluorinated linear esters, and one or more fluorinated esters (e.g., one or more fluorinated linear esters). According to some embodiments, a weight ratio of the one or more fluorinated cyclic carbonates to the combined weight of the one or more unfluorinated linear esters and the one or more fluorinated esters is greater than or equal to 0.25, greater than or equal to 0.3, greater than or equal to 0.35, greater than or equal to 0.4, greater than or equal to 0.45, greater than or equal to 0.5, greater than or equal to 0.55, greater than or equal to 0.6, greater than or equal to 0.65, greater than or equal to 0.7, greater than or equal to 0.75, greater than or equal to 0.8, greater than or equal to 0.85, greater than or equal to 0.9, or greater than or equal to 0.95. In some embodiments, a weight ratio of the one or more fluorinated cyclic carbonates to the combined weight of the one or more unfluorinated linear esters and the one or more fluorinated esters is less than or equal to 1, less than or equal to 0.95, less than or equal to 0.9, less than or equal to 0.85, less than or equal to 0.8, less than or equal to 0.75, less than or equal to 0.7, less than or equal to 0.65, less

[0135] #14755643vlthan or equal to 0.6, less than or equal to 0.55, less than or equal to 0.5, less than or equal to 0.45, less than or equal to 0.4, less than or equal to 0.35, or less than or equal to 0.3. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.25 and less than or equal to 1). Other ranges are also possible. In some embodiments, a weight ratio of all of the fluorinated cyclic carbonates in the electrolyte to the combined weight of all of the unfluorinated linear esters and all of the fluorinated esters in the electrolyte is in one or more of the above-referenced ranges.

[0136] In some embodiments, an electrolyte comprises one or more unfluorinated linear esters and one or more fluorinated esters. According to some embodiments, a weight ratio of the one or more unfluorinated linear esters to the one or more fluorinated esters is greater than or equal to 0.25, greater than or equal to 0.3, greater than or equal to 0.35, greater than or equal to 0.4, greater than or equal to 0.45, greater than or equal to 0.5, greater than or equal to 0.55, greater than or equal to 0.6, greater than or equal to 0.65, greater than or equal to 0.7, greater than or equal to 0.75, greater than or equal to 0.8, greater than or equal to 0.85, greater than or equal to 0.9, greater than or equal to 0.95, greater than or equal to 1, greater than or equal to 1.1, greater than or equal to 1.2, greater than or equal to 1.3, greater than or equal to 1.4, greater than or equal to 1.5, greater than or equal to 1.6, greater than or equal to 1.7, greater than or equal to 1.8, greater than or equal to 1.9, greater than or equal to 2, greater than or equal to 2.1, greater than or equal to 2.2, greater than or equal to 2.3, greater than or equal to 2.4, greater than or equal to 2.5, greater than or equal to 2.6, greater than or equal to 2.7, greater than or equal to 2.8, greater than or equal to 2.9, greater than or equal to 3, greater than or equal to 3.1, greater than or equal to 3.2, greater than or equal to 3.3, greater than or equal to 3.4, greater than or equal to 3.5, greater than or equal to 3.6, greater than or equal to 3.7, greater than or equal to 3.8, or greater than or equal to 3.9. In some embodiments, a weight ratio of the one or more unfluorinated linear esters to the one or more fluorinated esters is less than or equal to 4, less than or equal to 3.9, less than or equal to 3.8, less than or equal to 3.7, less than or equal to 3.6, less than or equal to 3.5, less than or equal to 3.4, less than or equal to 3.3, less than or equal to 3.2, less than or equal to 3.1, less than or equal to 3, less than or equal to 2.9, less than or equal to 2.8, less than or equal to 2.7, less than or equal to 2.6, less than or equal to 2.5, less than or equal to 2.4, less than or equal to 2.3, less than or equal to 2.2, less than or equal to

[0137] #14755643vl2.1, less than or equal to 2, less than or equal to 1.9, less than or equal to 1.8, less than or equal to 1.7, less than or equal to 1.6, less than or equal to 1.5, less than or equal to 1.4, less than or equal to 1.3, less than or equal to 1.2, less than or equal to 1.1, less than or equal to 1, less than or equal to 0.95, less than or equal to 0.9, less than or equal to 0.85, less than or equal to 0.8, less than or equal to 0.75, less than or equal to 0.7, less than or equal to 0.65, less than or equal to 0.6, less than or equal to 0.55, less than or equal to 0.5, less than or equal to 0.45, less than or equal to 0.4, less than or equal to 0.35, or less than or equal to 0.3. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.25 and less than or equal to 4). Other ranges are also possible. In some embodiments, a weight ratio of all of the unfluorinated linear esters in the electrolyte to all of the fluorinated esters in the electrolyte is in one or more of the above-referenced ranges.

[0138] In some embodiments, an electrolyte comprises one or more fluorinated cyclic carbonates, one or more unfluorinated linear esters, and one or more fluorinated ethers. According to some embodiments, a weight ratio of the one or more fluorinated cyclic carbonates to the combined weight of the one or more unfluorinated linear esters and the one or more fluorinated ethers is greater than or equal to 0.5, greater than or equal to 0.55, greater than or equal to 0.6, greater than or equal to 0.65, greater than or equal to 0.7, greater than or equal to 0.75, greater than or equal to 0.8, greater than or equal to 0.85, greater than or equal to 0.9, or greater than or equal to 0.95. In some embodiments, a weight ratio of the one or more fluorinated cyclic carbonates to the combined weight of the one or more unfluorinated linear esters and the one or more fluorinated ethers is less than or equal to 1, less than or equal to 0.95, less than or equal to 0.9, less than or equal to 0.85, less than or equal to 0.8, less than or equal to 0.75, less than or equal to 0.7, less than or equal to 0.65, less than or equal to 0.6, or less than or equal to 0.55.

[0139] Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.5 and less than or equal to 1). Other ranges are also possible. In some embodiments, a weight ratio of all of the fluorinated cyclic carbonates in the electrolyte to the combined weight of all of the unfluorinated linear esters and all of the fluorinated ethers in the electrolyte is in one or more of the above-referenced ranges.

[0140] In some embodiments, an electrolyte comprises one or more fluorinated cyclic carbonates and one or more unfluorinated linear esters. According to some embodiments,

[0141] #14755643vla weight ratio of the one or more fluorinated cyclic carbonates to the one or more unfluorinated linear esters is greater than or equal to 0.3, greater than or equal to 0.35, greater than or equal to 0.4, greater than or equal to 0.45, greater than or equal to 0.5, greater than or equal to 0.55, greater than or equal to 0.6, greater than or equal to 0.65, greater than or equal to 0.7, greater than or equal to 0.75, greater than or equal to 0.8, greater than or equal to 0.85, greater than or equal to 0.9, greater than or equal to 0.95, greater than or equal to 1, greater than or equal to 1.2, greater than or equal to 1.4, greater than or equal to 1.6, greater than or equal to 1.8, greater than or equal to 2, greater than or equal to 2.2, greater than or equal to 2.4, greater than or equal to 2.6, greater than or equal to 2.8, greater than or equal to 3, greater than or equal to 3.2, greater than or equal to 3.4, greater than or equal to 3.6, greater than or equal to 3.8, greater than or equal to 4, greater than or equal to 4.2, greater than or equal to 4.4, greater than or equal to 4.6, or greater than or equal to 4.8. In some embodiments, a weight ratio of the one or more fluorinated cyclic carbonates to the one or more unfluorinated linear esters is less than or equal to 5, less than or equal to 4.8, less than or equal to 4.6, less than or equal to 4.4, less than or equal to 4.2, less than or equal to 4, less than or equal to 3.8, less than or equal to 3.6, less than or equal to 3.4, less than or equal to 3.2, less than or equal to 3, less than or equal to 2.8, less than or equal to 2.6, less than or equal to 2.4, less than or equal to 2.2, less than or equal to 2, less than or equal to 1.8, less than or equal to 1.6, less than or equal to 1.4, less than or equal to 1.2, less than or equal to 1, less than or equal to 0.95, less than or equal to 0.9, less than or equal to 0.85, less than or equal to 0.8, less than or equal to 0.75, less than or equal to 0.7, less than or equal to 0.65, less than or equal to 0.6, less than or equal to 0.55, less than or equal to 0.5, less than or equal to 0.45, less than or equal to 0.4, or less than or equal to 0.35. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.3 and less than or equal to 5). Other ranges are also possible. In some embodiments, a weight ratio of all of the fluorinated cyclic carbonates in the electrolyte to all of the unfluorinated linear esters in the electrolyte is in one or more of the abovereferenced ranges.

[0142] In some embodiments, an electrolyte comprises one or more fluorinated cyclic carbonates and one or more fluorinated ethers. According to some embodiments, a weight ratio of the one or more fluorinated cyclic carbonates to the one or more

[0143] #14755643vlfluorinated ethers is greater than or equal to 0.3, greater than or equal to 0.35, greater than or equal to 0.4, greater than or equal to 0.45, greater than or equal to 0.5, greater than or equal to 0.55, greater than or equal to 0.6, greater than or equal to 0.65, greater than or equal to 0.7, greater than or equal to 0.75, greater than or equal to 0.8, greater than or equal to 0.85, greater than or equal to 0.9, greater than or equal to 0.95, greater than or equal to 1, greater than or equal to 1.2, greater than or equal to 1.4, greater than or equal to 1.6, greater than or equal to 1.8, greater than or equal to 2, greater than or equal to 2.2, greater than or equal to 2.4, greater than or equal to 2.6, greater than or equal to 2.8, greater than or equal to 3, greater than or equal to 3.2, greater than or equal to 3.4, greater than or equal to 3.6, greater than or equal to 3.8, greater than or equal to 4, greater than or equal to 4.2, greater than or equal to 4.4, greater than or equal to 4.6, or greater than or equal to 4.8. In some embodiments, a weight ratio of the one or more fluorinated cyclic carbonates to the one or more fluorinated ethers is less than or equal to 5, less than or equal to 4.8, less than or equal to 4.6, less than or equal to 4.4, less than or equal to 4.2, less than or equal to 4, less than or equal to 3.8, less than or equal to 3.6, less than or equal to 3.4, less than or equal to 3.2, less than or equal to 3, less than or equal to 2.8, less than or equal to 2.6, less than or equal to 2.4, less than or equal to 2.2, less than or equal to 2, less than or equal to 1.8, less than or equal to 1.6, less than or equal to 1.4, less than or equal to 1.2, less than or equal to 1, less than or equal to 0.95, less than or equal to 0.9, less than or equal to 0.85, less than or equal to 0.8, less than or equal to 0.75, less than or equal to 0.7, less than or equal to 0.65, less than or equal to 0.6, less than or equal to 0.55, less than or equal to 0.5, less than or equal to 0.45, less than or equal to 0.4, or less than or equal to 0.35. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.3 and less than or equal to 5). Other ranges are also possible. In some embodiments, a weight ratio of all of the fluorinated cyclic carbonates in the electrolyte to all of the fluorinated ethers in the electrolyte is in one or more of the above-referenced ranges.

[0144] In some embodiments, an electrolyte comprises one or more fluorinated cyclic carbonates and one or more fluorinated sulfonamides. According to some embodiments, a weight ratio of the one or more fluorinated cyclic carbonates to the one or more fluorinated sulfonamides is greater than or equal to 0.3, greater than or equal to 0.35, greater than or equal to 0.4, greater than or equal to 0.45, greater than or equal to 0.5,

[0145] #14755643vlgreater than or equal to 0.55, greater than or equal to 0.6, greater than or equal to 0.65, greater than or equal to 0.7, greater than or equal to 0.75, greater than or equal to 0.8, greater than or equal to 0.85, greater than or equal to 0.9, greater than or equal to 0.95, greater than or equal to 1, greater than or equal to 1.2, greater than or equal to 1.4, greater than or equal to 1.6, greater than or equal to 1.8, greater than or equal to 2, greater than or equal to 2.2, greater than or equal to 2.4, greater than or equal to 2.6, greater than or equal to 2.8, greater than or equal to 3, greater than or equal to 3.2, greater than or equal to 3.4, greater than or equal to 3.6, greater than or equal to 3.8, greater than or equal to 4, greater than or equal to 4.2, greater than or equal to 4.4, greater than or equal to 4.6, or greater than or equal to 4.8. In some embodiments, a weight ratio of the one or more fluorinated cyclic carbonates to the one or more fluorinated sulfonamides is less than or equal to 5, less than or equal to 4.8, less than or equal to 4.6, less than or equal to 4.4, less than or equal to 4.2, less than or equal to 4, less than or equal to 3.8, less than or equal to 3.6, less than or equal to 3.4, less than or equal to 3.2, less than or equal to 3, less than or equal to 2.8, less than or equal to 2.6, less than or equal to 2.4, less than or equal to 2.2, less than or equal to 2, less than or equal to 1.8, less than or equal to 1.6, less than or equal to 1.4, less than or equal to 1.2, less than or equal to 1, less than or equal to 0.95, less than or equal to 0.9, less than or equal to 0.85, less than or equal to 0.8, less than or equal to 0.75, less than or equal to 0.7, less than or equal to 0.65, less than or equal to 0.6, less than or equal to 0.55, less than or equal to 0.5, less than or equal to 0.45, less than or equal to 0.4, or less than or equal to 0.35. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.3 and less than or equal to 5). Other ranges are also possible. In some embodiments, a weight ratio of all of the fluorinated cyclic carbonates in the electrolyte to all of the fluorinated sulfonamides in the electrolyte is in one or more of the abovereferenced ranges.

[0146] In some embodiments, an electrolyte comprises one or more fluorinated cyclic carbonates and one or more fluorinated esters. According to some embodiments, a weight ratio of the one or more fluorinated cyclic carbonates to the one or more fluorinated esters is greater than or equal to 0.3, greater than or equal to 0.35, greater than or equal to 0.4, greater than or equal to 0.45, greater than or equal to 0.5, greater than or equal to 0.55, greater than or equal to 0.6, greater than or equal to 0.65, greater

[0147] #14755643vlthan or equal to 0.7, greater than or equal to 0.75, greater than or equal to 0.8, greater than or equal to 0.85, greater than or equal to 0.9, greater than or equal to 0.95, greater than or equal to 1, greater than or equal to 1.2, greater than or equal to 1.4, greater than or equal to 1.6, greater than or equal to 1.8, greater than or equal to 2, greater than or equal to 2.2, greater than or equal to 2.4, greater than or equal to 2.6, greater than or equal to 2.8, greater than or equal to 3, greater than or equal to 3.2, greater than or equal to 3.4, greater than or equal to 3.6, greater than or equal to 3.8, greater than or equal to 4, greater than or equal to 4.2, greater than or equal to 4.4, greater than or equal to 4.6, or greater than or equal to 4.8. In some embodiments, a weight ratio of the one or more fluorinated cyclic carbonates to the one or more fluorinated esters is less than or equal to 5, less than or equal to 4.8, less than or equal to 4.6, less than or equal to 4.4, less than or equal to 4.2, less than or equal to 4, less than or equal to 3.8, less than or equal to 3.6, less than or equal to 3.4, less than or equal to 3.2, less than or equal to 3, less than or equal to 2.8, less than or equal to 2.6, less than or equal to 2.4, less than or equal to 2.2, less than or equal to 2, less than or equal to 1.8, less than or equal to 1.6, less than or equal to 1.4, less than or equal to 1.2, less than or equal to 1, less than or equal to 0.95, less than or equal to 0.9, less than or equal to 0.85, less than or equal to 0.8, less than or equal to 0.75, less than or equal to 0.7, less than or equal to 0.65, less than or equal to 0.6, less than or equal to 0.55, less than or equal to 0.5, less than or equal to 0.45, less than or equal to 0.4, or less than or equal to 0.35. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.3 and less than or equal to 5). Other ranges are also possible. In some embodiments, a weight ratio of all of the fluorinated cyclic carbonates in the electrolyte to all of the fluorinated esters in the electrolyte is in one or more of the above-referenced ranges.

[0148] In some embodiments, an electrolyte comprises one or more unfluorinated linear esters and one or more fluorinated ethers. According to some embodiments, a weight ratio of the one or more unfluorinated linear esters to the one or more fluorinated ethers is greater than or equal to 0.25, greater than or equal to 0.3, greater than or equal to 0.35, greater than or equal to 0.4, greater than or equal to 0.45, greater than or equal to 0.5, greater than or equal to 0.55, greater than or equal to 0.6, greater than or equal to 0.65, greater than or equal to 0.7, greater than or equal to 0.75, greater than or equal to 0.8, greater than or equal to 0.85, greater than or equal to 0.9, greater than or equal to 0.95,

[0149] #14755643vlgreater than or equal to 1, greater than or equal to 1.1, greater than or equal to 1.2, greater than or equal to 1.3, greater than or equal to 1.4, greater than or equal to 1.5, greater than or equal to 1.6, greater than or equal to 1.7, greater than or equal to 1.8, greater than or equal to 1.9, greater than or equal to 2, greater than or equal to 2.1, greater than or equal to 2.2, greater than or equal to 2.3, greater than or equal to 2.4, greater than or equal to 2.5, greater than or equal to 2.6, greater than or equal to 2.7, greater than or equal to 2.8, greater than or equal to 2.9, greater than or equal to 3, greater than or equal to 3.1, greater than or equal to 3.2, greater than or equal to 3.3, greater than or equal to 3.4, greater than or equal to 3.5, greater than or equal to 3.6, greater than or equal to 3.7, greater than or equal to 3.8, or greater than or equal to 3.9. In some embodiments, a weight ratio of the one or more unfluorinated linear esters to the one or more fluorinated ethers is less than or equal to 4, less than or equal to 3.9, less than or equal to 3.8, less than or equal to 3.7, less than or equal to 3.6, less than or equal to 3.5, less than or equal to 3.4, less than or equal to 3.3, less than or equal to 3.2, less than or equal to 3.1, less than or equal to 3, less than or equal to 2.9, less than or equal to 2.8, less than or equal to 2.7, less than or equal to 2.6, less than or equal to 2.5, less than or equal to 2.4, less than or equal to 2.3, less than or equal to 2.2, less than or equal to 2.1, less than or equal to 2, less than or equal to 1.9, less than or equal to 1.8, less than or equal to 1.7, less than or equal to 1.6, less than or equal to 1.5, less than or equal to 1.4, less than or equal to 1.3, less than or equal to 1.2, less than or equal to 1.1, less than or equal to 1, less than or equal to 0.95, less than or equal to 0.9, less than or equal to 0.85, less than or equal to 0.8, less than or equal to 0.75, less than or equal to 0.7, less than or equal to 0.65, less than or equal to 0.6, less than or equal to 0.55, less than or equal to 0.5, less than or equal to 0.45, less than or equal to 0.4, less than or equal to 0.35, or less than or equal to 0.3. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.25 and less than or equal to 4). Other ranges are also possible. In some embodiments, a weight ratio of all of the unfluorinated linear esters in the electrolyte to all of the fluorinated ethers in the electrolyte is in one or more of the above -referenced ranges.

[0150] In some embodiments, an electrolyte may comprise a variety of suitable total amounts of fluorinated solvents. For example, in some embodiments, the total amount of fluorinated solvents in an electrolyte is greater than or equal to 30 wt%, greater than or

[0151] #14755643vlequal to 35 wt%, greater than or equal to 40 wt%, greater than or equal to 45 wt%, greater than or equal to 50 wt%, greater than or equal to 55 wt%, greater than or equal to 60 wt%, or greater than or equal to 65 wt% of the electrolyte. In some embodiments, the total amount of fluorinated solvents in an electrolyte is less than or equal to 70 wt%, less than or equal to 65 wt%, less than or equal to 60 wt%, less than or equal to 55 wt%, less than or equal to 50 wt%, less than or equal to 45 wt%, less than or equal to 40 wt%, or less than or equal to 35 wt% of the electrolyte. Combinations of the above-referenced ranges are also possible (e.g., greater than or equal to 30 wt% and less than or equal to 70 wt%). Other ranges are also possible.

[0152] According to some embodiments, an electrolyte comprises a salt (e.g., a lithium salt). Examples of ionic electrolyte salts for use in the electrolyte of the electrochemical cells described herein include, but are not limited to, LiSCN, LiBr, Lil, lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsFe), LiSOsCFs, LiSOsCHs, lithium tetrafluoroborate (LiBF4), LiB(Ph)4, lithium hexafluorophosphate (LiPFe), lithium trifluoromethanesulfonate (LiCFjSCF), Li SChCFs , lithium bis(trifhioromethanesulfonyl)imide (LiN SChCF?^), LiC(CnF2n+iSO2)3, wherein n is an integer in the range of from 1 to 20, LiN(SO2F)2, LiAlF4, LiNCF, Li2SiFe, LiSbFe, LiAlCL, LiBF2(C2O4), lithium bis-oxalatoborate (LiBOB), and / or salts of the general formula (CnF2n+iSO2)mXLi with n being an integer in the range of from 1 to 20, m being 1 when X is selected from oxygen or sulfur, m being 2 when X is selected from nitrogen or phosphorus, and m being 3 when X is selected from carbon or silicium. Other electrolyte salts that may be useful include lithium poly sulfides (Li2Sx), and lithium salts of organic polysulfides (LiSxR)n, where x is an integer from 1 to 20, n is an integer from 1 to 3, and R is an organic group, and those disclosed in U.S. Patent No. 5,538,812 to Lee et al., which is incorporated herein by reference in its entirety for all purposes.

[0153] In some embodiments, an electrolyte may comprise a salt in any of a variety of amounts. In some embodiments, the salt may be present in the electrolyte in an amount of greater than or equal to 0.1 wt%, greater than or equal to 0.5 wt%, greater than or equal to 1 wt%, greater than or equal to 2 wt%, greater than or equal to 3 wt%, greater than or equal to 4 wt%, greater than or equal to 5 wt%, greater than or equal to 6 wt%, greater than or equal to 7 wt%, greater than or equal to 8 wt%, greater than or equal to 9 wt%, greater than or equal to 10 wt%, greater than or equal to 11 wt%, greater than or

[0154] #14755643vlequal to 12 wt%, greater than or equal to 13 wt%, or greater than or equal to 14 wt% of the electrolyte. In some embodiments, the salt may be present in the electrolyte in an amount of less than or equal to 15 wt%, less than or equal to 14 wt%, less than or equal to 13 wt%, less than or equal to 12 wt%, less than or equal to 11 wt%, less than or equal to 10 wt%, less than or equal to 9 wt%, less than or equal to 8 wt%, less than or equal to 7 wt%, less than or equal to 6 wt%, less than or equal to 5 wt%, less than or equal to 4 wt%, less than or equal to 3 wt%, less than or equal to 2 wt%, less than or equal to 1 wt%, or less than or equal to 0.5 wt% of the electrolyte. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.1 wt% and less than or equal to 15 wt%). Other ranges are also possible.

[0155] In some embodiments, wherein the electrolyte comprises multiple salts (e.g., LiBF4 and LiPFe; LiFSI, LiBF4, and LiPFe), each salt may independently be present in the electrolyte in an amount that corresponds to the foregoing ranges and / or all of the salts together may make up an amount of the electrolyte that corresponds to the foregoing ranges. In some such cases, the amounts of each salt may be equal to each other. In other such cases, the amounts of each salt may be different from each other.

[0156] In some embodiments, the molar ratio of the total amount of coordinating solvent in the electrolyte to the total amount of salt in the electrolyte is greater than or equal to 1, greater than or equal to 1.1, greater than or equal to 1.2, greater than or equal to 1.3, greater than or equal to 1.4, greater than or equal to 1.5, greater than or equal to 1.6, greater than or equal to 1.7, greater than or equal to 1.8, or greater than or equal to 1.9. In some embodiments, the molar ratio of the total amount of coordinating solvent in the electrolyte to the total amount of salt in the electrolyte is less than or equal to 2, less than or equal to 1.9, less than or equal to 1.8, less than or equal to 1.7, less than or equal to 1.6, less than or equal to 1.5, less than or equal to 1.4, less than or equal to 1.3, less than or equal to 1.2, or less than or equal to 1.1. Combinations of the above-referenced ranges are also possible (e.g., greater than or equal to 1 and less than or equal to 2, or greater than or equal to 1.2 and less than or equal to 1.8). Other ranges are also possible.

[0157] For example, in some embodiments, an electrolyte may comprise a LiPFe in any of a variety of amounts. In some embodiments, the LiPFe may be present in the electrolyte in an amount of greater than or equal to 0.1 wt%, greater than or equal to 0.5 wt%, greater than or equal to 1 wt%, greater than or equal to 2 wt%, greater than or equal

[0158] #14755643vlto 3 wt%, greater than or equal to 4 wt%, greater than or equal to 5 wt%, greater than or equal to 6 wt%, greater than or equal to 7 wt%, greater than or equal to 8 wt%, greater than or equal to 9 wt%, greater than or equal to 10 wt%, greater than or equal to 11 wt%, greater than or equal to 12 wt%, greater than or equal to 13 wt%, or greater than or equal to 14 wt% of the electrolyte. In some embodiments, the LiPFe may be present in the electrolyte in an amount of less than or equal to 15 wt%, less than or equal to 14 wt%, less than or equal to 13 wt%, less than or equal to 12 wt%, less than or equal to 11 wt%, less than or equal to 10 wt%, less than or equal to 9 wt%, less than or equal to 8 wt%, less than or equal to 7 wt%, less than or equal to 6 wt%, less than or equal to 5 wt%, less than or equal to 4 wt%, less than or equal to 3 wt%, less than or equal to 2 wt%, less than or equal to 1 wt%, or less than or equal to 0.5 wt% of the electrolyte. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.1 wt% and less than or equal to 15 wt%). Other ranges are also possible.

[0159] For example, in some embodiments, an electrolyte may comprise a LiFSI in any of a variety of amounts. In some embodiments, the LiFSI may be present in the electrolyte in an amount of greater than or equal to 20 wt%, greater than or equal to 25 wt%, greater than or equal to 30 wt%, or greater than or equal to 35 wt% of the electrolyte. In some embodiments, the LiFSI may be present in the electrolyte in an amount of less than or equal to 40 wt%, less than or equal to 35 wt%, less than or equal to 30 wt%, or less than or equal to 25 wt% of the electrolyte. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 20 wt% and less than or equal to 40 wt%). Other ranges are also possible.

[0160] For example, in some embodiments, an electrolyte may comprise a LiBF4 in any of a variety of amounts. In some embodiments, the LiBF4 may be present in the electrolyte in an amount of greater than or equal to 0.1 wt%, greater than or equal to 0.5 wt%, greater than or equal to 1 wt%, greater than or equal to 2 wt%, greater than or equal to 3 wt%, greater than or equal to 4 wt%, greater than or equal to 5 wt%, greater than or equal to 6 wt%, greater than or equal to 7 wt%, greater than or equal to 8 wt%, greater than or equal to 9 wt%, greater than or equal to 10 wt%, greater than or equal to 11 wt%, greater than or equal to 12 wt%, greater than or equal to 13 wt%, or greater than or equal to 14 wt% of the electrolyte. In some embodiments, the LiBF4 may be present in the electrolyte in an amount of less than or equal to 15 wt%, less than or equal to 14 wt%,

[0161] #14755643vlless than or equal to 13 wt%, less than or equal to 12 wt%, less than or equal to 11 wt%, less than or equal to 10 wt%, less than or equal to 9 wt%, less than or equal to 8 wt%, less than or equal to 7 wt%, less than or equal to 6 wt%, less than or equal to 5 wt%, less than or equal to 4 wt%, less than or equal to 3 wt%, less than or equal to 2 wt%, less than or equal to 1 wt%, or less than or equal to 0.5 wt% of the electrolyte. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.1 wt% and less than or equal to 15 wt%, or greater than or equal to 0.1 wt% and less than or equal to 2 wt%). Other ranges are also possible. In some embodiments, the LiBF4 is included in the electrolyte in a relatively small amount, e.g., less than or equal to 5 wt%, less than or equal to 4 wt%, less than or equal to 3 wt% of the electrolyte, or so forth as described in the foregoing ranges.

[0162] In some embodiments, an electrolyte comprises prop-l-ene-l,3-sultone and LiBF4. Without wishing to be bound by any particular theory, it is believed that this combination may be unexpectedly and particularly beneficial for localized high-concentration electrolytes. Each of these species on their own may affect the solvation of ions, sometimes undesirably displacing anions or solvent molecules from the primary solvation shell and / or produce new coordinated clusters. This disruption may disadvantageously increase the amount of free solvent present in the electrolyte and / or lead to the formation of separated ion pairs. When such effects occur, they may vitiate the advantages of localized high-concentration electrolytes described elsewhere herein, result in the inclusion of more organic content in the SEI and / or the CEI, result in SEIs and / or CEIs that are less stable, increase interfacial impedance, and / or reduce cycle life. However, it is believed that, although each of prop-l-ene-l,3-sultone and LiBF4 on its own may produce one or more such effects, both species together may reduce gassing (which is believed to be due to the CEI including fewer organic species), and / or enhance cycle life (which is believed to be due to reduced polarization) when present in certain electrolytes.

[0163] According to some embodiments, a weight ratio of the prop-l-ene-l,3-sultone to the LiBF4 is greater than or equal to 0.5, greater than or equal to 0.6, greater than or equal to 0.7, greater than or equal to 0.8, greater than or equal to 0.9, greater than or equal to 1, greater than or equal to 1.1, greater than or equal to 1.2, greater than or equal to 1.3, greater than or equal to 1.4, greater than or equal to 1.5, greater than or equal to

[0164] #14755643vl1.6, greater than or equal to 1.7, greater than or equal to 1.8, or greater than or equal to 1.9. According to some embodiments, a weight ratio of the prop-l-ene-l,3-sultone to the LiBF4 is less than or equal to 2, less than or equal to 1.9, less than or equal to 1.8, less than or equal to 1.7, less than or equal to 1.6, less than or equal to 1.5, less than or equal to 1.4, less than or equal to 1.3, less than or equal to 1.2, less than or equal to 1.1, less than or equal to 1, less than or equal to 0.9, less than or equal to 0.8, less than or equal to 0.7, or less than or equal to 0.6. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 0.5 and less than or equal to 2). Other ranges are also possible.

[0165] In some embodiments, an electrolyte comprises prop-l-ene-l,3-sultone and LiBF4. According to some embodiments, prop-l-ene-l,3-sultone and LiBF4 together make up greater than or equal to 1 wt%, greater than or equal to 1.5 wt%, greater than or equal to 2 wt%, greater than or equal to 2.5 wt%, greater than or equal to 3 wt%, greater than or equal to 3.5 wt%, greater than or equal to 4 wt%, greater than or equal to 4.5 wt%, greater than or equal to 5 wt%, greater than or equal to 5.5 wt%, greater than or equal to 6 wt%, greater than or equal to 6.5 wt%, greater than or equal to 7 wt%, greater than or equal to 7.5 wt%, greater than or equal to 8 wt%, greater than or equal to 8.5 wt%, greater than or equal to 9 wt%, or greater than or equal to 9.5 wt% of the electrolyte. According to some embodiments, prop-l-ene-l,3-sultone and LiBF4 together make up less than or equal to 10 wt%, less than or equal to 9.5 wt%, less than or equal to 9 wt%, less than or equal to 8.5 wt%, less than or equal to 8 wt%, less than or equal to 7.5 wt%, less than or equal to 7 wt%, less than or equal to 6.5 wt%, less than or equal to 6 wt%, less than or equal to 5.5 wt%, less than or equal to 5 wt%, less than or equal to 4.5 wt%, less than or equal to 4 wt%, less than or equal to 3.5 wt%, less than or equal to 3 wt%, less than or equal to 2.5 wt%, less than or equal to 2 wt%, or less than or equal to 1.5 wt% of the electrolyte. Combinations of the foregoing ranges are possible (e.g., greater than or equal to 1 wt% and less than or equal to 10 wt% of the electrolyte). Other ranges are also possible.

[0166] An electrolyte of an electrochemical cell may comprise some and / or all of the foregoing components. In some embodiments, the electrolyte may comprise a fluorinated ester, an unfluorinated carbonate, a fluorinated ether, a sultone, and / or one or more salts. According to some embodiments, the electrolyte may comprise a fluorinated cyclic carbonate, an unfluorinated linear ester, and a fluorinated ether. In some embodiments,

[0167] #14755643vlthe electrolyte comprises a fluorinated cyclic carbonate, an unfluorinated linear ester, and a fluorinated sulfonamide (e.g., a N, N di-alkyl sulfamoyl fluoride). In some embodiments, the electrolyte comprises a fluorinated cyclic carbonate, an unfluorinated linear ester, and a fluorinated ester. In some embodiments, the electrolyte comprises a fluorinated ether, a fluorinated sulfonamide (e.g., a N, N di-alkyl sulfamoyl fluoride), a fluorinated ester, a sultone, and / or a salt such as LiBF4. In some embodiments, the electrolyte may comprise FEC, EMC, HFE, LiPFe, PES, and / or LiBF4. In some embodiments, the electrolyte may comprise FEC, EMC, HFE, LiPFe, PES, LiN(SO2F)2, and / or LiBF4. In some embodiments, the electrolyte may comprise a fluorinated ester, an unfluorinated carbonate, a sulfonamide, and / or one or more salts. In some embodiments, the electrolyte may comprise FEC, EMC, N,N-dimethylsulfamoyl fluoride, and LiPFe.

[0168] A variety of electrodes can be used in the embodiments described herein. In some embodiments, an electrochemical cell comprises an anode (e.g., a first electrode), which may comprise an anode active material. For example, an electrode may be an anode and may comprise a lithium-containing material, wherein lithium is the anode active material. Suitable anode active materials (e.g., for use in electrodes that are anodes) include, but are not limited to, lithium metal such as lithium foil and lithium deposited onto a conductive substrate, and lithium alloys (e.g., lithium-aluminum alloys and lithium-tin alloys). Methods for depositing an anode active material (e.g., an alkali metal such as lithium) onto a substrate may include methods such as thermal evaporation, sputtering, jet vapor deposition, and laser ablation. In some embodiments, where an electrode comprises a lithium foil, the lithium foil can be laminated to a current collector by a lamination process.

[0169] In some embodiments (e.g., when the electrochemical cell is a lithium-metal cell), an electrochemical cell comprises an electrode from which lithium ions are liberated during discharge and into which the lithium ions are integrated (e.g., intercalated) during charge. In some embodiments, an electrode that is an anode comprises an anode active material that is a lithium intercalation compound (e.g., a compound that is capable of reversibly inserting lithium ions at lattice sites and / or interstitial sites). In some embodiments, the anode active material comprises carbon. In some cases, the anode active material is or comprises a graphitic material (e.g., graphite). A graphitic material generally refers to a material that comprises a plurality of layers of

[0170] #14755643vlgraphene (i.e., layers comprising carbon atoms covalently bonded in a hexagonal lattice). Adjacent graphene layers are typically attracted to each other via van der Waals forces, although covalent bonds may be present between one or more sheets in some cases. In some cases, the carbon-comprising anode active material is or comprises coke (e.g., petroleum coke). In some embodiments, the anode active material comprises silicon, lithium, and / or any alloys of combinations thereof. In some embodiments, the anode active material comprises lithium titanate (Li4Ti50i2, also referred to as “LTO”), tincobalt oxide, or any combinations thereof.

[0171] In some embodiments, an anode-active material containing lithium present in an electrode (e.g., an anode) comprises greater than or equal to 50% by weight of lithium. In some embodiments, the anode-active material containing lithium present in an electrode comprises greater than or equal to 75% or greater than or equal to 90% by weight of lithium. Additional materials (e.g., anode active materials and / or cathode active materials, as described elsewhere herein) and arrangements suitable for use in an electrode are described, for example, in U.S. Patent Publication No. 2010 / 0035128 to Scordilis-Kelley et al. filed on August 4, 2009, entitled “Application of Force in Electrochemical Cells,” which is incorporated herein by reference in its entirety for all purposes.

[0172] In some cases, the lithium metal / lithium metal alloy may be present during only a portion of charge / discharge cycles. For example, the cell can be constructed without any lithium metal / lithium metal alloy on a first current collector, and the lithium metal / lithium metal alloy may subsequently be deposited on the first current collector during a charging step. In some embodiments, lithium may be completely depleted after discharging such that lithium is present during only a portion of the charge / discharge cycle.

[0173] In some embodiments, an electrochemical cell comprises a cathode (e.g., a second electrode) that comprises a cathode active material. Examples of cathode active materials include, but are not limited to, one or more metal oxides, electroactive transition metal chalcogenides, electroactive conductive polymers, sulfur, carbon and / or combinations thereof. In some embodiments, the cathode comprises a nickel cobalt manganese (NCM) cathode. In some embodiments, the cathode comprises a lithium iron

[0174] #14755643vlphosphate (LFP), lithium cobalt oxide (LCO), lithium manganese oxide (LMO), and / or a lithium manganese iron phosphate (LMFP) cathode.

[0175] In some embodiments, an intercalation electrode (e.g., a lithium-intercalation electrode) may be used as the cathode active material. Non-limiting examples of suitable materials that may intercalate ions of a cathode active material (e.g., alkaline metal ions) include metal oxides, titanium sulfide, and iron sulfide. In some embodiments, an electrode (e.g., a cathode) is an intercalation electrode comprising a lithium transition metal oxide (e.g., a nickel-containing intercalation compound, an LCO and / or NMC electrode) and / or a lithium transition metal phosphate (e.g., LFP and / or LMFP). Nonlimiting examples of lithium transition metal oxides and phosphates include LixCo02 (e.g., Lii.iCo02, which is an LCO electrode), LixNiO2, LixMnO2, LixMn2O4 (e.g., Lii.osMmCU), LixCoP04, LixMnP04. For the preceding materials, x may be greater than or equal to 0 and less than or equal to 2. x is typically greater than or equal to 1 and less than or equal to 2 when the electrochemical cell is fully discharged, and less than 1 when the electrochemical cell is fully charged. In some embodiments, a fully charged electrochemical cell may have a value of x that is greater than or equal to 1 and less than or equal to 1.05, greater than or equal to 1 and less than or equal to 1.1, or greater than or equal to 1 and less than or equal to 1.2.

[0176] Further non-limiting examples of lithium transition metal oxides include LiCoxNi(i-x)02 where x is less than or equal to 1, and LiCoxNiyMn(i-x-y)02 (e.g., an NMC electrode) where x and y are less than or equal to 1 and (e.g., LiNimMnmCoi Ch, LiNi3 / 5Mm / 5Coi / 502, LiNi4 / 5Mm / ioCoi / io02, LiNii^M / ioCoi / sCL). For example, x (and y) may each independently be between 0.05 and 0.8. Further examples of lithium transition metal oxides and phosphates include LixNiPO4, where (0 < x < 1), LiMnxNiyO4 where (x + y = 2) (e.g., LiMm.5Nio.5O4), LiNixCoyAlz02 where (x + y + z =1), LiFePO4 (i.e., a lithium iron phosphate electrode, an LFP electrode), and combinations thereof. In some embodiments, a cathode active material within an electrode (e.g., a cathode) comprises lithium transition metal phosphates (e.g., LiFePO4), which can, in some embodiments, be substituted with borates and / or silicates. In some embodiments, a cathode active material within an electrode (e.g., a cathode) comprises lithium transition metal phosphates (e.g., an LFP electrode) and another transition metal, e.g., substituting manganese for a portion of the iron in an LFP electrode to form a LMFP electrode.

[0177] #14755643vlIn some embodiments, the cathodes (e.g., the second electrode) comprising a lithium transition metal oxide comprise nickel. In some embodiments, nickel makes up at least 80 wt%, at least 82 wt%, at least 84 wt%, at least 86 wt%, at least 88 wt%, at least 90 wt%, at least 92 wt%, at least 94 wt%, at least 96 wt%, or at least 98 wt% of the cathode and / or the cathode active material.

[0178] In some embodiments, a cathode active material comprises one or more chalcogenides. As used herein, the term “chalcogenides” pertains to compounds that contain one or more of the elements of oxygen, sulfur, and selenium. Examples of suitable transition metal chalcogenides include, but are not limited to, the electroactive oxides, sulfides, and selenides of transition metals selected from the group consisting of Mn, V, Cr, Ti, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta, W, Re, Os, and Ir. In some embodiments, a transition metal chalcogenide is selected from the group consisting of the electroactive oxides of nickel, manganese, cobalt, and vanadium, and the electroactive sulfides of iron. In some embodiments, a cathode includes one or more of the following materials: manganese dioxide, iodine, silver chromate, silver oxide and vanadium pentoxide, copper oxide, copper oxyphosphate, lead sulfide, copper sulfide, iron sulfide, lead bismuthate, bismuth trioxide, cobalt dioxide, copper chloride, manganese dioxide, and carbon.

[0179] In some embodiments, a cathode active material comprises an electroactive conductive polymer. Examples of suitable electroactive conductive polymers include, but are not limited to, electroactive and electronically conductive polymers selected from the group consisting of polypyrroles, polyanilines, polyphenylenes, polythiophenes, and polyacetylenes. Examples of conductive polymers include polypyrroles, polyanilines, and polyacetylenes.

[0180] The anode active and / or cathode active material of an electrode (e.g., an anode or a cathode) may be present in an amount of 20% to 100% by weight of the electrode. In some embodiments, the amount of anode active and / or cathode active materials is in the range of 5-30% by weight of the electrode. In another embodiment, the amount of anode active and / or cathode active material in the electrode is in the range of 20% to 90% by weight of the electrode. In some embodiments, the anode active and cathode active materials described herein may be modified (e.g., via vapor deposition or slurry method) with one or more of a metal or a metal-containing compounds. Non-limiting examples of

[0181] #14755643vlsuch metal-containing compound include, but are not limited to, AI2O3, Z1O2, SiCh, AIF3, TiCh, LiAlCh, and various metals (e.g., Al).

[0182] An electrochemical cell may comprise an appropriate number of electrodes. In some embodiments, for example, an electrochemical cell comprises a first electrode that is an anode, and a second electrode that is a cathode. In some embodiments, the electrochemical cell does not initially contain a first electrode. For example, an electrochemical cell may be configured such that a first electrode (e.g., an anode) is not formed until the electrochemical cell is initially charged, according to some embodiments. Thus, the electrochemical cell may comprise one or more electrodes.

[0183] In some embodiments, an electrochemical cell includes a separator. The separator generally comprises a polymeric material (e.g., polymeric material that does or does not swell upon exposure to electrolyte). In some embodiments, the separator is located between the first electrode and the second electrode (e.g., the anode and the cathode).

[0184] Pores of a separator may be partially or substantially filled with liquid electrolyte. Separators may be supplied as porous free-standing films which are interleaved with the first electrode and / or the second electrode (e.g., the anode and the cathode) during the fabrication of cells. It is also possible that the porous separator layer may be applied directly to the surface of one of the electrodes, in some embodiments, for example, as described in PCT Publication No. WO 99 / 33125 to Carlson et al. and in U.S. Patent No.

[0185] 5,194,341 to Bagley et al.

[0186] Examples of suitable solid porous separator materials include, but are not limited to, polyolefins, such as, for example, polyethylenes (e.g., SETELA™ made by Tonen Chemical Corp) and polypropylenes, glass fiber filter papers, and ceramic materials. For example, in some embodiments, the separator comprises a microporous polyethylene film. Further examples of separators and separator materials suitable for use in the electrochemical cells described herein are those comprising a microporous xerogel layer, for example, a microporous pseudo-boehmite layer, which may be provided either as a free standing film or by a direct coating application on one of the electrodes (e.g., the second electrode), as described in U.S. Patent Nos. 6,153,337 and 6,306,545 by Carlson et al. Solid electrolytes and gel electrolytes may also function as a separator in addition to their electrolyte function.

[0187] #14755643vl-M- Separators may comprise a polymeric material (e.g., polymeric material that does or does not swell upon exposure to electrolyte). In some embodiments, the separator is located between the electrolyte and an electrode (e.g., between the electrolyte and a first electrode, between the electrolyte and a second electrode, between the electrolyte and the first electrode, or between the electrolyte and the second electrode).

[0188] A separator can be made of a variety of materials. The separator may be polymeric in some instances, or formed of an inorganic material (e.g., glass fiber filter papers) in other instances. Examples of suitable separator materials include, but are not limited to, polyolefins (e.g., polyethylenes, poly(butene-l), poly(n-pentene-2), polypropylene, polytetrafluoroethylene), polyamines (e.g., polyethylene imine) and polypropylene imine (PPI)); polyamides (e.g., polyamide (Nylon), poly(e-caprolactam) (Nylon 6), poly(hexamethylene adipamide) (Nylon 66)), polyimides (e.g., polyimide, polynitrile, and poly(pyromellitimide-l,4-diphenyl ether) (Kapton®) (NOMEX®) (KEVLAR®)); polyether ether ketone (PEEK); vinyl polymers (e.g., polyacrylamide, poly(2-vinyl pyridine), poly(N-vinylpyrrolidone), poly(methylcyanoacrylate), poly (ethylcyanoacrylate), poly(butylcyanoacrylate), poly(isobutylcyanoacrylate), poly (vinyl acetate), poly (vinyl alcohol), poly (vinyl chloride), poly (vinyl fluoride), poly(2-vinyl pyridine), vinyl polymer, polychlorotrifluoro ethylene, and poly(isohexylcynaoacrylate)); polyacetals; polyesters (e.g., polycarbonate, polybutylene terephthalate, polyhydroxybutyrate); polyethers (polyethylene oxide) (PEO), polypropylene oxide) (PPO), poly(tetramethylene oxide) (PTMO)); vinylidene polymers (e.g., polyisobutylene, poly(methyl styrene), poly(methylmethacrylate) (PMMA), poly(vinylidene chloride), and poly(vinylidene fluoride)); polyaramides (e.g., poly(imino-l,3-phenylene iminoisophthaloyl) and poly(imino-l,4-phenylene iminoterephthaloyl)); polyheteroaromatic compounds (e.g., polybenzimidazole (PBI), polybenzobisoxazole (PBO) and polybenzobisthiazole (PBT)); polyheterocyclic compounds (e.g., polypyrrole); polyurethanes; phenolic polymers (e.g., phenolformaldehyde); polyalkynes (e.g., poly acetylene); polydienes (e.g., 1,2-polybutadiene, cis or trans- 1,4-polybutadiene); polysiloxanes (e.g., poly(dimethylsiloxane) (PDMS), poly(diethylsiloxane) (PDES), polydiphenylsiloxane (PDPS), and polymethylphenylsiloxane (PMPS)); and inorganic polymers (e.g., polyphosphazene, polyphosphonate, polysilanes, poly silazanes). In some embodiments, the polymer may

[0189] #14755643vlbe selected from poly(n-pentene-2), polypropylene, polytetrafluoroethylene, polyamides (e.g., polyamide (Nylon), poly(e-caprolactam) (Nylon 6), poly(hexamethylene adipamide) (Nylon 66)), polyimides (e.g., polynitrile, and poly(pyromellitimide-l,4-diphenyl ether) (Kapton®) (NOMEX®) (KEVLAR®)), polyether ether ketone (PEEK), and combinations thereof. In some embodiments, the separator may comprise a polymeric material coated with a ceramic material. In some embodiments, the ceramic material may be coated on one side of the polymeric material or on both sides of the polymeric material. In certain embodiments, the ceramic material comprises an oxide, a phosphate, and / or a sulfate. Non-limiting examples of ceramic materials that may be coated on one or both sides of the separator include alumina, boehmite, and BaSCU.

[0190] In some embodiments, an electrochemical cell comprises a protective layer over the cathode active and / or anode active material of the electrode (e.g., a first electrode, a second electrode). Generally, a “protective layer” is a layer of material that protects the anode active and / or cathode active material of the electrode from non-electrochemical chemical reactions or other unfavorable interaction with species within the electrochemical cell. An electrode of the electrochemical cell may comprise one or more coatings or layers formed from polymers, ceramics, and / or glasses. The coating may serve as a protective layer and may serve different functions. For example, the protective layer can be configured to prevent chemical reaction or other unfavorable interaction between the electrode active material and a species within the electrolyte and / or between the electrode active material and a side product of the electrochemical reaction within the electrochemical cell. Functions of the protective layer may include preventing the formation of dendrites during recharging which could otherwise cause short circuiting, preventing reaction of the electrode active material with electrolyte, and improving cycle life. Examples of such protective layers include those described in: U.S. Patent No. 8,338,034 to Affinito et al. and U.S. Patent Publication No. 2015 / 0236322 to Laramie at al., each of which is incorporated herein by reference in its entirety for all purposes.

[0191] According to some embodiments, the protective layer is over the anode active material of an anode. For example, the protective layer is disposed between the anode and the separator, according to some embodiments. In some such embodiments, the protective layer may be in direct contact with the anode active material of the anode.

[0192] #14755643vlAccording to some embodiments, the protective layer is over the cathode active material of a cathode.

[0193] The electrochemical cells described herein may comprise one or more current collectors, as mentioned above. In some cases, the electrochemical cells comprise an anodic current collector (e.g., first current collector 52 in FIG. 1A). The anodic current collector may be electronically coupled to an anode and / or a plurality of anode portions of the electrochemical device.

[0194] In some embodiments, the electrochemical cells described herein comprise a cathodic current collector (e.g., second current collector 54 in FIG. 1A). The cathodic current collector may be electronically coupled to a cathode and / or a plurality of cathode portions of the electrochemical cell.

[0195] In some embodiments, an electrolyte is or comprises a fluid electrolyte (e.g., a liquid; an electrolyte that comprises a solvent) that can be added at any suitable point in the fabrication process. In some cases, the electrochemical cell is fabricated by providing a first electrode and optionally a second electrode (e.g., an anode and a cathode), applying an anisotropic force component normal to the active surface of the first electrode and / or second electrode, and subsequently adding the fluid electrolyte such that the electrolyte is in electrochemical communication with the first electrode and the optional second electrode, if present. In other cases, the fluid electrolyte is added to the electrochemical cell prior to or simultaneously with the application of an anisotropic force component, after which the electrolyte is in electrochemical communication with the first electrode and the optional second electrode, if present. In some embodiments, the fluid electrolyte is added to the electrochemical cell without the application of anisotropic force, and no anisotropic force is subsequently applied.

[0196] In some embodiments, an electrochemical cell comprising an electrolyte as described elsewhere herein may be cycled. Cycling generally refers to performing one or more charge / discharge cycles using the electrochemical cell. In some embodiments, the cycling of the electrochemical cell forms an SEI on a surface of at least one electrode (e.g., an anode and / or cathode) present in the electrochemical cell. In some embodiments, cycling the electrochemical cell forms and SEI on an active surface of an anode. In some embodiments, the cycling of the electrochemical cell is performed under an anisotropic force normal to a surface of an electrode of the electrochemical cell

[0197] #14755643vlcomprising lithium metal. In some embodiments, the cycling performance of the electrochemical cell comprising an electrolyte as described herein while applying an anisotropic force to the electrochemical cell improves relative to an electrochemical cell having a different electrolyte and / or an electrochemical cell that has no anisotropic force applied during cycling.

[0198] In some embodiments, the electrical resistance of the electrochemical cell decreases during cycling. For example, in some embodiments, after undergoing 50 cycles, the electrical resistance of the electrochemical cell is at least 20%, at least 30%, at least 40%, or at least 50% less than the initial resistance of the electrochemical cell.

[0199] In some embodiments, an amount of lithium may be lost during cycling (e.g., becomes electrolytically inactive). In some embodiments, an amount of lithium loss per cycle (e.g., from the anode) is less than or equal to 0.03 microns, less than or equal to 0.025 microns, less than or equal to 0.02 microns, less than or equal to 0.015 microns, or less than or equal to 0.01 microns. In some embodiments, an amount of lithium loss (e.g., from the anode) per Ah is less than or equal to 0.1 micron, less than or equal to 0.9 microns, less than or equal to 0.08 microns, less than or equal to 0.07 microns, less than or equal to 0.06 microns, less than or equal to 0.05 microns, less than or equal to 0.04 microns, less than or equal to 0.03 microns, less than or equal to 0.02 microns, or less than or equal to 0.01 microns.

[0200] In some embodiments, the electrochemical cell has a figure of merit that is equal to a product of a depth of discharge of the electrochemical cell and a cycle life of the electrochemical cell. In some embodiments, the figure of merit of the electrochemical cell is greater than or equal to 8.

[0201] In some embodiments, it can be advantageous to apply an anisotropic force to the electrochemical cells described herein during charge and / or discharge. In some embodiments, the electrochemical cells and / or the electrodes described herein can be configured to withstand an applied anisotropic force (e.g., a force applied to enhance the morphology of an electrode within the cell) while maintaining their structural integrity. The electrodes described herein may be a part of an electrochemical cell that is adapted and arranged such that, during at least one period of time during charge and / or discharge of the cell, an anisotropic force with a component normal to the active surface of an electrode within the electrochemical cell (e.g., an anode comprising lithium metal and / or

[0202] #14755643vla lithium alloy) is applied to the cell. In one set of embodiments, the applied anisotropic force can be selected to enhance the morphology of an electrode (e.g., an anode such as a lithium metal and / or a lithium alloy anode). As understood in the art, an “anisotropic force” is a force that is not equal in all directions.

[0203] In some such cases, an anisotropic force comprises a component normal to an active surface of an electrode (e.g., a first electrode such as a cathode, a second electrode such as an anode) within an electrochemical cell. As used herein, the term “active surface” is used to describe a surface of an electrode at which electrochemical reactions may take place. A force with a “component normal” to a surface is given its ordinary meaning as would be understood by those of ordinary skill in the art and includes, for example, a force which at least in part exerts itself in a direction substantially perpendicular to the surface. For example, in the case of a horizontal table with an object resting on the table and affected only by gravity, the object exerts a force essentially completely normal to the surface of the table. If the object is also urged laterally across the horizontal table surface, then it exerts a force on the table which, while not completely perpendicular to the horizontal surface, includes a component normal to the table surface. Those of ordinary skill will understand other examples of these terms, especially as applied within the description of this document. In the case of a curved surface (for example, a concave surface or a convex surface), the component of the anisotropic force that is normal to an active surface of an electrode may correspond to the component normal to a plane that is tangent to the curved surface at the point at which the anisotropic force is applied. The anisotropic force may be applied, in some cases, at one or more pre-determined locations, optionally distributed over the active surface of the anode. In some embodiments, the anisotropic force is applied uniformly over the active surface of the first electrode (e.g., an anode) and / or the second electrode (e.g., a cathode).

[0204] Referring back to FIG. 1A, which illustrates an exemplary electrochemical cell as described herein, a force may be applied in the direction of arrow 58. Arrow 60 illustrates the component of force 58 that is normal to cathode active surface portion 56 of cathode 44 as well as anode active surface 50 of anode 42. In some embodiments, some or all of the force may be applied in direction 60 to be normal to the anode active surface 50 and the cathode active surface 56.

[0205] #14755643vlAny of the electrochemical cell properties and / or performance metrics described herein may be achieved, alone or in combination with each other, while an anisotropic force is applied to the electrochemical cell (e.g., during charge and / or discharge of the cell) during charge and / or discharge. In some embodiments, the anisotropic force applied to the electrode, to the electrochemical cell (e.g., during at least one period of time during charge and / or discharge of the cell) can include a component normal to an active surface of an electrode (e.g., an anode such as a lithium metal and / or lithium alloy anode within the electrochemical cell). In some embodiments, the component of the anisotropic force that is normal to the active surface of the electrode defines a pressure of greater than or equal to 1 kg / cm2, greater than or equal to 2 kg / cm2, greater than or equal to 4 kg / cm2, greater than or equal to 6 kg / cm2, greater than or equal to 8 kg / cm2, greater than or equal to 10 kg / cm2, greater than or equal to 12 kg / cm2, greater than or equal to 14 kg / cm2, greater than or equal to 16 kg / cm2, greater than or equal to 18 kg / cm2, greater than or equal to 20 kg / cm2, greater than or equal to 22 kg / cm2, greater than or equal to 24 kg / cm2, greater than or equal to 26 kg / cm2, greater than or equal to 28 kg / cm2, greater than or equal to 30 kg / cm2, greater than or equal to 32 kg / cm2, greater than or equal to 34 kg / cm2, greater than or equal to 36 kg / cm2, greater than or equal to 38 kg / cm2, greater than or equal to 40 kg / cm2, greater than or equal to 42 kg / cm2, greater than or equal to 44 kg / cm2, greater than or equal to 46 kg / cm2, or greater than or equal to 48 kg / cm2. In some embodiments, the component of the anisotropic force normal to the active surface may, for example, define a pressure of less than or equal to 50 kg / cm2, less than or equal to 48 kg / cm2, less than or equal to 46 kg / cm2, less than or equal to 44 kg / cm2, less than or equal to 42 kg / cm2, less than or equal to 40 kg / cm2, less than or equal to 38 kg / cm2, less than or equal to 36 kg / cm2, less than or equal to 34 kg / cm2, less than or equal to 32 kg / cm2, less than or equal to 30 kg / cm2, less than or equal to 28 kg / cm2, less than or equal to 26 kg / cm2, less than or equal to 24 kg / cm2, less than or equal to 22 kg / cm2, less than or equal to 20 kg / cm2, less than or equal to 18 kg / cm2, less about 16 kg / cm2, less than or equal to 14 kg / cm2, less than or equal to 12 kg / cm2, less than or equal to 10 kg / cm2, less than or equal to 8 kg / cm2, less than or equal to 6 kg / cm2, less than or equal to 4 kg / cm2, or less than or equal to 2 kg / cm2. Combinations of the above-referenced ranges are also possible (e.g., greater than or equal to 1 kg / cm2and less than or equal to 50 kg / cm2). Other ranges are possible.

[0206] #14755643vlAnisotropic forces applied during charge and / or discharge as described herein may be applied using any method known in the art. In some embodiments, the force may be applied using compression springs. Forces may be applied using other elements (either inside or outside a containment structure) including, but not limited to Belleville washers, machine screws, pneumatic devices, and / or weights, among others. In some cases, cells may be pre-compressed before they are inserted into containment structures, and, upon being inserted to the containment structure, they may expand to produce a net force on the cell. Suitable methods for applying such forces are described in detail, for example, in U.S. Patent No. 9,105,938, which is incorporated herein by reference in its entirety.

[0207] In some embodiments, an electrochemical cell described herein is included in a battery. Generally, a battery comprises a first electrochemical cell and a second electrochemical cell — one or both of which may include an electrode that has an electrolyte as described elsewhere herein. A battery may comprise greater than or equal to 2, greater than or equal to 3, greater than or equal to 4, greater than or equal to 5, greater than or equal to 6, greater than or equal to 7, greater than or equal to 8, greater than or equal to 9, greater than or equal to 10, greater than or equal to 15, greater than or equal to 25, or more electrochemical cells.

[0208] In some embodiments, the electrochemical cells and batteries (e.g., rechargeable batteries) described in this disclosure can be used to provide power to an electric vehicle or otherwise be incorporated into an electric vehicle. As a non-limiting example, an electrochemical cell and / or a battery described in this disclosure (e.g., comprising lithium metal and / or lithium alloy electrochemical cells) can, in some embodiments, be used to provide power to a drive train of an electric vehicle. The vehicle may be any suitable vehicle, adapted for travel on land, sea, and / or air. For example, the vehicle may be an automobile, truck, motorcycle, boat, helicopter, airplane, and / or any other suitable type of vehicle. FIG. 2 shows a cross-sectional schematic diagram of electric vehicle 101 in the form of an automobile comprising battery 100, in accordance with some embodiments. Battery 100 can, in some instances, provide power to a drive train of electric vehicle 101.

[0209] The term “aliphatic,” as used herein, includes both saturated and unsaturated, nonaromatic, straight chain (i.e., unbranched), branched, acyclic, and cyclic (i.e.,

[0210] #14755643vlcarbocyclic) hydrocarbons, which are optionally substituted with one or more functional groups. As will be appreciated by one of ordinary skill in the art, “aliphatic” is intended herein to include, but is not limited to, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, and cycloalkynyl moieties. Likewise, the term “heteroaliphatic” refers to heteroalkyl, heteroalkenyl, heteroalkynyl, and heterocyclic groups. Thus, as used herein, the term “alkyl” includes straight, branched and cyclic alkyl groups. An analogous convention applies to other generic terms such as “alkenyl”, “alkynyl”, and the like. Furthermore, as used herein, the terms “alkyl”, “alkenyl”, “alkynyl”, and the like encompass both substituted and unsubstituted groups. In some embodiments, as used herein, “aliphatic” is used to indicate those aliphatic groups (cyclic, acyclic, substituted, unsubstituted, branched or unbranched) having 1-20 carbon atoms. Aliphatic group substituents include, but are not limited to, any of the substituents described herein, that result in the formation of a stable moiety (e.g., aliphatic, alkyl, alkenyl, alkynyl, hetero aliphatic, heterocyclic, aryl, heteroaryl, acyl, oxo, imino, thiooxo, cyano, isocyano, amino, azido, nitro, hydroxyl, thiol, halo, aliphaticamino, heteroaliphaticamino, alkylamino, heteroalkylamino, arylamino, heteroarylamino, alkylaryl, arylalkyl, aliphaticoxy, heteroaliphaticoxy, alkyloxy, heteroalkyloxy, aryloxy, heteroaryloxy, aliphaticthioxy, heteroaliphaticthioxy, alkylthioxy, heteroalkylthioxy, arylthioxy, heteroarylthioxy, acyloxy, and the like, each of which may or may not be further substituted).

[0211] The term “alkyl” refers to the radical of saturated aliphatic groups, including straight-chain alkyl groups, branched-chain alkyl groups, cycloalkyl (alicyclic) groups, alkyl substituted cycloalkyl groups, and cycloalkyl substituted alkyl groups. The alkyl groups may be optionally substituted, as described more fully below. Examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, 2-ethylhexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like.

[0212] The term “haloaliphatic” refers to an aliphatic group, wherein one or more hydrogen atoms, such as one to 10 hydrogen atoms, are independently replaced with a halogen atom, such as fluoro, bromo, chloro, or iodo.

[0213] The term “haloheteroaliphatic” refers to a heteroaliphatic group, wherein one or more hydrogen atoms, such as one to 10 hydrogen atoms, are independently replaced with a halogen atom, such as fluoro, bromo, chloro, or iodo.

[0214] #14755643vlThe terms “amine” and “amino” refer to both unsubstituted and substituted amines, e.g., a moiety that can be represented by the general formula: N(R’)(R”)(R”’) wherein R’, R”, and R’” each independently represent a group permitted by the rules of valence.

[0215] The terms “acyl,” “carboxyl group,” or “carbonyl group” are recognized in the art and can include such moieties as can be represented by the general formula:

[0216]

[0217] wherein W is H, OH, O-alkyl, O-alkenyl, or a salt thereof. Where W is O-alkyl, the formula represents an “ester.” On the other hand, where W is alkyl, the above formula represents a “ketone” group. Where W is hydrogen, the above formula represents an “aldehyde” group.

[0218] As used herein, the term "heteroaromatic" or “heteroaryl" means a monocyclic or polycyclic heteroaromatic ring (or radical thereof) comprising carbon atom ring members and one or more heteroatom ring members (such as, for example, oxygen, sulfur or nitrogen). Typically, the heteroaromatic ring has from 5 to about 14 ring members in which at least 1 ring member is a heteroatom selected from oxygen, sulfur, and nitrogen. In another embodiment, the hetero aromatic ring is a 5 or 6 membered ring and may contain from 1 to about 4 heteroatoms. In another embodiment, the heteroaromatic ring system has a 7 to 14 ring members and may contain from 1 to about 7 heteroatoms. Representative heteroaryls include pyridyl, furyl, thienyl, pyrrolyl, oxazolyl, imidazolyl, indolizinyl, thiazolyl, isoxazolyl, pyrazolyl, isothiazolyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, triazolyl, pyridinyl, thiadiazolyl, pyrazinyl, quinolyl, isoquinolyl, indazolyl, benzoxazolyl, benzofuryl, benzothiazolyl, indolizinyl, imidazopyridinyl, isothiazolyl, tetrazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, benzothiadiazolyl, benzoxadiazolyl, carbazolyl, indolyl, tetrahydroindolyl, azaindolyl, imidazopyridyl, qunizaolinyl, purinyl, pyrrolo[2,3]pyrimidyl, pyrazolo[3,4]pyrimidyl, benzo (b)thienyl, and the like. These heteroaryl groups may be optionally substituted with one or more substituents.

[0219] The term “substituted” is contemplated to include all permissible substituents of organic compounds, “permissible” being in the context of the chemical rules of valence known to those of ordinary skill in the art. In some cases, “substituted” may generally

[0220] #14755643vlrefer to replacement of a hydrogen with a substituent as described herein. However, “substituted,” as used herein, does not encompass replacement and / or alteration of a key functional group by which a molecule is identified, e.g., such that the “substituted” functional group becomes, through substitution, a different functional group. For example, a “substituted phenyl” must still comprise the phenyl moiety and cannot be modified by substitution, in this definition, to become, e.g., a heteroaryl group such as pyridine. In a broad aspect, the permissible substituents include acyclic and cyclic, branched and unbranched, carbocyclic and heterocyclic, aromatic and nonaromatic substituents of organic compounds. Illustrative substituents include, for example, those described herein. The permissible substituents can be one or more and the same or different for appropriate organic compounds. For purposes of this invention, the heteroatoms such as nitrogen may have hydrogen substituents and / or any permissible substituents of organic compounds described herein which satisfy the valencies of the heteroatoms. This invention is not intended to be limited in any manner by the permissible substituents of organic compounds.

[0221] Examples of substituents include, but are not limited to, alkyl, aryl, aralkyl, cyclic alkyl, heterocycloalkyl, hydroxy, alkoxy, aryloxy, perhaloalkoxy, aralkoxy, heteroaryl, heteroaryloxy, heteroarylalkyl, heteroaralkoxy, azido, amino, halogen, alkylthio, oxo, acyl, acylalkyl, carboxy esters, carboxyl, carboxamido, nitro, acyloxy, aminoalkyl, alkylaminoaryl, alkylaryl, alkylaminoalkyl, alkoxyaryl, arylamino, aralkylamino, alkylsulfonyl, carboxamidoalkylaryl, carboxamidoaryl, hydroxyalkyl, haloalkyl, alkylaminoalkylcarboxy, aminocarboxamidoalkyl, alkoxyalkyl, perhaloalkyl, arylalkyloxyalkyl, and the like.

[0222] It should be understood that when a portion (e.g., layer, structure, region) is “on”, “adjacent”, “above”, “over”, “overlying”, or “supported by” another portion, it can be directly on the portion, or an intervening portion (e.g., layer, structure, region) also may be present. Similarly, when a portion is “below” or “underneath” another portion, it can be directly below the portion, or an intervening portion (e.g., layer, structure, region) also may be present. A portion that is “directly on”, “directly adjacent”, “immediately adjacent”, “in direct contact with”, or “directly supported by” another portion means that no intervening portion is present. It should also be understood that when a portion is referred to as being “on”, “above”, “adjacent”, “over”, “overlying”, “in contact with”,

[0223] #14755643vl“below”, or “supported by” another portion, it may cover the entire portion or a part of the portion.

[0224] In some embodiments, electrochemical cells are described.

[0225] In some embodiments, an electrochemical cell comprises an electrode comprising lithium metal and an electrolyte, wherein the electrolyte comprises a fluorinated cyclic carbonate, an unfluorinated linear ester, and a fluorinated ether, wherein a weight ratio of the fluorinated cyclic carbonate to a combined weight of the unfluorinated linear ester and the fluorinated ether is greater than or equal to 0.25 and less than or equal to 1, and wherein a weight ratio of the unfluorinated linear ester to the fluorinated ether is greater than or equal to 0.25 and less than or equal to 4.

[0226] In some embodiments, an electrochemical cell comprises an electrode comprising lithium metal and an electrolyte, wherein the electrolyte comprises a fluorinated cyclic carbonate, an unfluorinated linear ester, and a fluorinated sulfonamide, wherein a weight ratio of the fluorinated cyclic carbonate to a combined weight of the unfluorinated linear ester and the fluorinated sulfonamide is greater than or equal to 0.25 and less than or equal to 1, and wherein a weight ratio of the unfluorinated linear ester to the fluorinated sulfonamide is greater than or equal to 0.25 and less than or equal to 4.

[0227] In some embodiments, an electrochemical cell comprises an electrode comprising lithium metal and an electrolyte, wherein the electrolyte comprises a fluorinated cyclic carbonate, an unfluorinated linear ester, and a fluorinated linear ester, wherein a weight ratio of the fluorinated cyclic carbonate to a combined weight of the unfluorinated linear ester and the fluorinated linear ester is greater than or equal to 0.25 and less than or equal to 1, and wherein a weight ratio of the unfluorinated linear ester to the fluorinated linear ester is greater than or equal to 0.25 and less than or equal to 4.

[0228] In some embodiments, methods are described. In some embodiments, the method comprises cycling an electrochemical cell, wherein the electrochemical cell comprises an electrode comprising lithium metal, the electrochemical cell comprises an electrolyte, the electrolyte comprises a sultone and LiBF4, the electrolyte comprises a fluorinated ether, a fluorinated sulfonamide, and / or a fluorinated ester, and the cycling is performed under an anisotropic force normal to a surface of the electrode comprising lithium metal.

[0229] The following applications are incorporated herein by reference, in their entirety, for all purposes: U.S. Publication No. US-2007-0221265-A1 published on September 27,

[0230] #14755643vl2007, filed as U.S. Application No. 11 / 400,781 on April 6, 2006, and entitled “RECHARGEABLE LITHIUM / WATER, LITHIUM / AIR BATTERIES”; U.S.

[0231] Publication No. US-2009-0035646-A1, published on February 5, 2009, filed as U.S. Application No. 11 / 888,339 on July 31, 2007, and entitled “SWELLING INHIBITION IN BATTERIES”; U.S. Publication No. US-2010-0129699-A1 published on May 17, 2010, filed as U.S. Application No. 12 / 312,764 on February 2, 2010; patented as U.S. Patent No. 8,617,748 on December 31, 2013, and entitled “SEPARATION OF ELECTROLYTES”; U.S. Publication No. US-2010-0291442-A1 published on November 18, 2010, filed as U.S. Application No. 12 / 682,011 on July 30, 2010, patented as U.S. Patent No. 8,871,387 on October 28, 2014, and entitled “PRIMER FOR BATTERY ELECTRODE”; U.S. Publication No. US-2009-0200986-A1 published on August 13, 2009, filed as U.S. Application No. 12 / 069,335 on February 8, 2008, patented as U.S. Patent No. 8,264,205 on September 11, 2012, and entitled “CIRCUIT FOR CHARGE AND / OR DISCHARGE PROTECTION IN AN ENERGY-STORAGE DEVICE”; U.S. Publication No. US-2007-0224502-A1 published on September 27, 2007, filed as U.S. Application No. 11 / 400,025 on April 6, 2006, patented as U.S. Patent No. 7,771,870 on August 10, 2010, and entitled “ELECTRODE PROTECTION IN BOTH AQUEOUS AND NON-AQUEOUS ELECTROCHEMICAL CELLS, INCLUDING RECHARGEABLE LITHIUM BATTERIES”; U.S. Publication No. US-2008-0318128-A1 published on December 25, 2008, filed as U.S. Application No.

[0232] 11 / 821,576 on June 22, 2007, and entitled “LITHIUM ALLOY / SULFUR BATTERIES”; U.S. Publication No. US-2002-0055040-A1 published on May 9, 2002, filed as U.S. Application No. 09 / 795,915 on February 27, 2001, patented as U.S. Patent No. 7,939,198 on May 10, 2011, and entitled “NOVEL COMPOSITE CATHODES, ELECTROCHEMICAL CELLS COMPRISING NOVEL COMPOSITE CATHODES, AND PROCESSES FOR FABRICATING SAME”; U.S. Publication No. US-2006-0238203-A1 published on October 26, 2006, filed as U.S. Application No. 11 / 111,262 on April 20, 2005, patented as U.S. Patent No. 7,688,075 on March 30, 2010, and entitled “LITHIUM SULFUR RECHARGEABLE BATTERY FUEL GAUGE SYSTEMS AND METHODS”; U.S. Publication No. US-2008-0187663-A1 published on August 7, 2008, filed as U.S. Application No. 11 / 728,197 on March 23, 2007, patented as U.S. Patent No. 8,084,102 on December 27, 2011, and entitled “METHODS

[0233] #14755643vlFOR CO-FLASH EVAPORATION OF POLYMERIZABLE MONOMERS AND NONPOL YMERIZABLE CARRIER SOLVENT / SALT MIXTURES / SOLUTIONS”; U.S. Publication No. US-2011-0006738-Al published on January 13, 2011, filed as U.S. Application No. 12 / 679,371 on September 23, 2010, and entitled “ELECTROLYTE ADDITIVES FOR LITHIUM BATTERIES AND RELATED METHODS”; U.S.

[0234] Publication No. US-2011-0008531-Al published on January 13, 2011, filed as U.S. Application No. 12 / 811,576 on September 23, 2010, patented as U.S. Patent No.

[0235] 9,034,421 on May 19, 2015, and entitled “METHODS OF FORMING ELECTRODES COMPRISING SULFUR AND POROUS MATERIAL COMPRISING CARBON”; U.S. Publication No. US-2010-0035128-A1 published on February 11, 2010, filed as U.S. Application No. 12 / 535,328 on August 4, 2009, patented as U.S. Patent No.

[0236] 9,105,938 on August 11, 2015, and entitled “APPLICATION OF FORCE IN ELECTROCHEMICAL CELLS”; U.S. Publication No. US-2011-0165471-A9 published on July 15, 2011, filed as U.S. Application No. 12 / 180,379 on July 25, 2008, and entitled “PROTECTION OF ANODES FOR ELECTROCHEMICAL CELLS”; U.S. Publication No. US-2006-0222954-A1 published on October 5, 2006, filed as U.S. Application No.

[0237] 11 / 452,445 on June 13, 2006, patented as U.S. Patent No. 8,415,054 on April 9, 2013, and entitled “LITHIUM ANODES FOR ELECTROCHEMICAL CELLS”; U.S.

[0238] Publication No. US-2010-0239914-A1 published on September 23, 2010, filed as U.S. Application No. 12 / 727,862 on March 19, 2010, and entitled “CATHODE FOR LITHIUM BATTERY”; U.S. Publication No. US-2010-0294049-A1 published on November 25, 2010, filed as U.S. Application No. 12 / 471,095 on May 22, 2009, patented as U.S. Patent No. 8,087,309 on January 3, 2012, and entitled “HERMETIC SAMPLE HOLDER AND METHOD FOR PERFORMING MICROANALYSIS UNDER CONTROLLED ATMOSPHERE ENVIRONMENT”; U.S. Publication No. US-2011-0076560-Al published on March 31, 2011, filed as U.S. Application No.

[0239] 12 / 862,581 on August 24, 2010, and entitled “ELECTROCHEMICAL CELLS COMPRISING POROUS STRUCTURES COMPRISING SULFUR”; U.S. Publication No. US-2011-0068001-Al published on March 24, 2011, filed as U.S. Application No.

[0240] 12 / 862,513 on August 24, 2010, and entitled “RELEASE SYSTEM FOR ELECTROCHEMICAL CELLS”; U.S. Publication No. US-2012-0048729-A1 published on March 1, 2012, filed as U.S. Application No. 13 / 216,559 on August 24, 2011, and

[0241] #14755643vlentitled “ELECTRICALLY NON-CONDUCTIVE MATERIALS FOR ELECTROCHEMICAL CELLS”; U.S. Publication No. US-2011-0177398-Al published on July 21, 2011, filed as U.S. Application No. 12 / 862,528 on August 24, 2010, patented as U.S. Patent No. 10,629,947 on April 21, 2020, and entitled “ELECTROCHEMICAL CELL”; U.S. Publication No. US-2011-0070494-Al published on March 24, 2011, filed as U.S. Application No. 12 / 862,563 on August 24, 2010, and entitled “ELECTROCHEMICAL CELLS COMPRISING POROUS STRUCTURES COMPRISING SULFUR”; U.S. Publication No. US-2011-0070491-Al published on March 24, 2011, filed as U.S. Application No. 12 / 862,551 on August 24, 2010, and entitled “ELECTROCHEMICAL CELLS COMPRISING POROUS STRUCTURES COMPRISING SULFUR”; U.S. Publication No. US-2011-0059361-Al published on March 10, 2011, filed as U.S. Application No. 12 / 862,576 on August 24, 2010, patented as U.S. Patent No. 9,005,809 on April 14, 2015, and entitled “ELECTROCHEMICAL CELLS COMPRISING POROUS STRUCTURES COMPRISING SULFUR”; U.S. Publication No. US-2012-0052339-A1 published on March 1, 2012, filed as U.S.

[0242] Application No. 13 / 216,579 on August 24, 2011, and entitled “ELECTROLYTE MATERIALS FOR USE IN ELECTROCHEMICAL CELLS”; U.S. Publication No. US-2012-0070746-A1 published on March 22, 2012, filed as U.S. Application No.

[0243] 13 / 240,113 on September 22, 2011, and entitled “LOW ELECTROLYTE ELECTROCHEMICAL CELLS”; U.S. Publication No. US-2011-0206992-Al published on August 25, 2011, filed as U.S. Application No. 13 / 033,419 on February 23, 2011, and entitled “POROUS STRUCTURES FOR ENERGY STORAGE DEVICES”; U.S.

[0244] Publication No. US-2012-0082872-A1 published on April 5, 2012, filed as U.S.

[0245] Application No. 13 / 249,605 on September 30, 2011, and entitled “ADDITIVE FOR ELECTROLYTES”; U.S. Publication No. US-2012-0082901-A1 published on April 5, 2012, filed as U.S. Application No. 13 / 249,632 on September 30, 2011, and entitled “LITHIUM-BASED ANODE WITH IONIC LIQUID POLYMER GEL”; U.S.

[0246] Publication No. US-2013-0164635-A1 published on June 27, 2013, filed as U.S.

[0247] Application No. 13 / 700,696 on March 6, 2013, patented as U.S. Patent No. 9,577,243 on February 21 2017, and entitled “USE OF EXPANDED GRAPHITE IN LITHIUM / SULPHUR BATTERIES”; U.S. Publication No. US-2013-0017441-A1 published on January 17, 2013, filed as U.S. Application No. 13 / 524,662 on June 15,

[0248] #14755643vl2012, patented as U.S. Patent No. 9,548,492 on January 17, 2017, and entitled “PLATING TECHNIQUE FOR ELECTRODE”; U.S. Publication No. US-2013-0224601-A1 published on August 29, 2013, filed as U.S. Application No. 13 / 766,862 on February 14, 2013, patented as U.S. Patent No. 9,077,041 on July 7, 2015, and entitled “ELECTRODE STRUCTURE FOR ELECTROCHEMICAL CELL”; U.S. Publication No. US-2013-0252103-A1 published on September 26, 2013, filed as U.S. Application No. 13 / 789,783 on March 8, 2013, patented as U.S. Patent No. 9,214,678 on December 15, 2015, and entitled “POROUS SUPPORT STRUCTURES, ELECTRODES CONTAINING SAME, AND ASSOCIATED METHODS”; U.S. Publication No. US-2015-0287998-A1 published on October 8, 2015, filed as U.S. Application No.

[0249] 14 / 743,304 on June 18, 2015, patented as U.S. Patent No. 9,577,267 on February 21, 2017, and entitled “ELECTRODE STRUCTURE AND METHOD FOR MAKING SAME”; U.S. Publication No. US-2013-0095380-A1 published on April 18, 2013, filed as U.S. Application No. 13 / 644,933 on October 4, 2012, patented as U.S. Patent No. 8,936,870 on January 20, 2015, and entitled “ELECTRODE STRUCTURE AND METHOD FOR MAKING THE SAME”; U.S. Publication No. US-2012-0052397-A1 published on March 1, 2012, filed as U.S. Application No. 13 / 216,538 on August 24, 2011, patented as U.S. Patent No. 9,853,287 on December 26, 2017, and entitled “ELECTROLYTE MATERIALS FOR USE IN ELECTROCHEMICAL CELLS”; U.S. Publication No. US-2014-0123477-A1 published on May 8, 2014, filed as U.S.

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[0255] Application No. 15 / 727,438 on October 6, 2017, and entitled “PRESSURE AND / OR TEMPERATURE MANAGEMENT IN ELECTROCHEMICAL SYSTEMS”; U.S. Publication No. US-2014-0193713-A1 published on July 10, 2014, filed as U.S.

[0256] Application No. 14 / 150,196 on January 8, 2014, patented as U.S. Patent No. 9,531,009 on December 27, 2016, and entitled “PASSIVATION OF ELECTRODES IN ELECTROCHEMICAL CELLS”; U.S. Publication No. US-2014-0127577-A1 published on May 8, 2014, filed as U.S. Application No. 14 / 068,333 on October 31, 2013, patented as U.S. Patent No. 10,243,202 on March 26, 2019, and entitled “POLYMERS FOR USE AS PROTECTIVE LAYERS AND OTHER COMPONENTS IN ELECTROCHEMICAL CELLS”; U.S. Publication No. US-2015-0318539-A1 published on November 5, 2015, filed as U.S. Application No. 14 / 700,258 on April 30, 2015, patented as U.S. Patent No. 9,711,784 on July 18, 2017, and entitled “ELECTRODE FABRICATION METHODS AND ASSOCIATED SYSTEMS AND ARTICLES”; U.S. Publication No. US-2014-0272565-A1 published on September 18, 2014, filed as U.S.

[0257] #14755643vlApplication No. 14 / 209,396 on March 13, 2014, patented as U.S. Patent No. 10,862,105 on December 8, 2020 and entitled “PROTECTED ELECTRODE STRUCTURES”; U.S. Publication No. US-2015-0010804-A1 published on January 8, 2015, filed as U.S.

[0258] Application No. 14 / 323,269 on July 3, 2014, patented as U.S. Patent No. 9,994,959 on June 12, 2018, and entitled “CERAMIC / POLYMER MATRIX FOR ELECTRODE PROTECTION IN ELECTROCHEMICAL CELLS, INCLUDING RECHARGEABLE LITHIUM BATTERIES”; U.S. Publication No. US-2015-0162586-A1 published on June 11, 2015, filed as U.S. Application No. 14 / 561,305 on December 5, 2014, and entitled “NEW SEPARATOR”; U.S. Publication No. US-2015-0044517-A1 published on February 12, 2015, filed as U.S. Application No. 14 / 455,230 on August 8, 2014, patented as U.S. Patent No. 10,020,479 on July 10, 2018, and entitled “SELF-HEALING ELECTRODE PROTECTION IN ELECTROCHEMICAL CELLS”; U.S. Publication No. US-2015-0236322-A1 published on August 20, 2015, filed as U.S. Application No.

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[0262] Application No. 15 / 343,890 on November 4, 2016, and entitled “LAYER COMPOSITE AND ELECTRODE HAVING A SMOOTH SURFACE, AND ASSOCIATED METHODS”; U.S. Publication No. US-2017-0141442-A1 published on May 18, 2017, filed as U.S. Application No. 15 / 349,140 on November 11, 2016, and entitled “ADDITIVES FOR ELECTROCHEMICAL CELLS”; patented as U.S. Patent No.

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[0270] Application No. 15 / 765,362 on April 2, 2018, and entitled “NON-AQUEOUS ELECTROLYTES FOR HIGH ENERGY LITHIUM-ION BATTERIES”; U.S.

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[0272] Application No. 16,527,903 on July 31, 2019, and entitled “MULTIPLEXED CHARGE DISCHARGE BATTERY MANAGEMENT SYSTEM”; U.S. Publication No. US-2020-0220146-A1 published July 9, 2020, filed as U.S. Application No. 16 / 724,586 on December 23, 2019, and entitled “ISOLATABLE ELECTRODES AND ASSOCIATED ARTICLES AND METHODS”; U.S. Publication No. US-2020-0220149-A1 published

[0273] #14755643vlJuly 9, 2020, filed as U.S. Application No. 16 / 724,596 on December 23, 2019, and entitled “ELECTRODES, HEATERS, SENSORS, AND ASSOCIATED ARTICLES AND METHODS”; U.S. Publication No. US-2020-0220197-A1 published July 9, 2020, filed as U.S. Application No. 16 / 724,612 on December 23, 2019, and entitled “FOLDED ELECTROCHEMICAL DEVICES AND ASSOCIATED METHODS AND SYSTEMS”, U.S. Publication No. US-2020-0373578-A1 published November 26, 2020, filed as U.S. Application No. 16 / 879,861 on May 21, 2020, and entitled “ELECTROCHEMICAL DEVICES INCLUDING POROUS LAYERS”, U.S.

[0274] Publication No. US-2020-0373551-Al published November 26, 2020, filed as U.S. Application No. 16 / 879,839 on May 21, 2020, and entitled “ELECTRICALLY COUPLED ELECTRODES, AND ASSOCIATED ARTICLES AND METHODS”, U.S. Publication No. US-2020-0395585-A1 published December 17, 2020, filed as U.S.

[0275] Application No. 16 / 057,050 on August 7, 2018, and entitled “LITHIUM-COATED SEPARATORS AND ELECTROCHEMICAL CELLS COMPRISING THE SAME”, U.S. Publication No. US-2021-0057753-A1 published February 25, 2021, filed as U.S. Application No. 16 / 994,006 on August 14, 2020, and entitled “ELECTROCHEMICAL CELLS AND COMPONENTS COMPRISING THIOL GROUP-CONTAINING SPECIES”, U.S. Publication No. US-2021-0135297-A1 published on May 6, 2021, filed as U.S. Application No. 16 / 670,905 on October 31, 2019, and entitled SYSTEM AND METHOD FOR OPERATING A RECHARGEABLE ELECTROCHEMICAL CELL OR BATTERY”, U.S. Publication No. US-2021-0138673-A1 published on May 13, 2021, filed as U.S. Application No. 17 / 089,092 on November 4, 2020, and entitled “ELECTRODE CUTTING INSTRUMENT”, U.S. Publication No. US-2021-0135294-A1 published on May 6, 2021, filed as U.S. Application No. 16 / 670,933 on October 31, 2019, patented as U.S. Patent No. 11,056,728 on July 6, 2021 and entitled “SYSTEM AND METHOD FOR OPERATING A RECHARGEABLE ELECTROCHEMICAL CELL OR BATTERY”; U.S. Publication No. US-2021-0151839-A1 published on May 20, 2021, filed as U.S. Application No. 16 / 952,177 on November 19, 2020, and entitled “BATTERIES, AND ASSOCIATED SYSTEMS AND METHODS”; U.S. Publication No. US-2021-0151830-A1 published on May 20, 2021, filed as U.S. Application No. 16 / 952,235 on November 19, 2020, and entitled “BATTERIES WITH COMPONENTS INCLUDING CARBON FIBER, AND ASSOCIATED SYSTEMS AND METHODS”;

[0276] #14755643vlU.S. Publication No. US-2021-0151817-A1 published on May 20, 2021, filed as U.S. Application No. 16 / 952,228 on November 19, 2020, and entitled “BATTERY ALIGNMENT, AND ASSOCIATED SYSTEMS AND METHODS”; U.S. Publication No. US-2021-0151841-A1 published on May 20, 2021, filed as U.S. Application No. 16 / 952,240 on November 19, 2020, and entitled “SYSTEMS AND METHODS FOR APPLYING AND MAINTAINING COMPRESSION PRESSURE ON ELECTROCHEMICAL CELLS”; U.S. Publication No. US-2021-0151816-A1 published on May 20, 2021, filed as U.S. Application No. 16 / 952,223 on November 19, 2020, and entitled “THERMALLY INSULATING COMPRESSIBLE COMPONENTS FOR BATTERY PACKS”; U.S. Publication No. US-2021-0151840-A1 published on May 20, 2021, filed as U.S. Application No. 16 / 952,187 on November 19, 2020, and entitled “COMPRESSION SYSTEMS FOR BATTERIES”; U.S. Publication No. US-2021-0193984-A1 published on June 24, 2021, filed as U.S. Application No. 17 / 125,124 on December 17, 2020, and entitled “SYSTEMS AND METHODS FOR FABRICATING LITHIUM METAL ELECTRODES”; U.S. Publication No. US-2021-0193985-A1 published on June 24, 2021, filed as U.S. Application No. 17 / 125,110 on December 17, 2020, and entitled “LITHIUM METAL ELECTRODES AND METHODS”; U.S.

[0277] Publication No. US-2021-0193996-A1 published on June 24, 2021, filed as U.S.

[0278] Application No. 17 / 125,070 on December 17, 2020, and entitled “LITHIUM METAL ELECTRODES”; U.S. Publication No. US-2021-0194069-A1 published on June 24, 2021, filed as U.S. Application No. 17 / 126,390 on December 18, 2020, and entitled “SYSTEMS AND METHODS FOR PROVIDING, ASSEMBLING, AND MANAGING INTEGRATED POWER BUS FOR RECHARGEABLE ELECTROCHEMICAL CELL OR BATTERY”; U.S. Publication No. US-2021-0218243 published on July 15, 2021, filed as U.S. Application No. 17 / 126,424 on December 18, 2020, and entitled “SYSTEMS AND METHODS FOR PROTECTING A CIRCUIT, RECHARGEABLE ELECTROCHEMICAL CELL, OR BATTERY”; U.S. Publication No. 2022-0069593 published on March 3, 2022, filed as U.S. Application No. 17 / 463,467 filed on August 31, 2021, and entitled “Multiplexed Battery Management System”; U.S. Publication No.

[0279] 2022-0048121 published on February 17, 2022, filed as U.S. Application No. 17 / 397,114 filed on August 9, 2021, and entitled “Ultrasonic Blade for Cutting a Metal”, U.S.

[0280] Publication No. 2022-0115715 published on April 14, 2022, filed as U.S. Application

[0281] #14755643vlNo. 17 / 479,299 filed on September 20, 2021 and entitled “Electrolytes for Reduced Gassing”.

[0282] The following examples are intended to illustrate certain embodiments of the present invention, but do not exemplify the full scope of the invention.

[0283] EXAMPLES EXAMPLE 0

[0284] The following examples describe embodiments generally related to the electrochemical cells disclosed herein. Unless otherwise noted, the electrochemical cells Examples 1-5 were prepared by using the following materials and methods. The anode was commercially available Li foil (2 milliinches-thick (2 mil thick, approximately 50.8 micrometers thick)) from Rockwood Lithium. Only half of the Li foil was available for use as the anode in each electrochemical cell. Accordingly, a thickness of 1 milliinch (approximately 25.4 micrometers) of the Li foil was available for cycling per electrochemical cell (e.g., 1 milliinch (approximately 25.4 micrometers)) of Li foil thickness per cathode). The porous separator used in the electrochemical cells was a 9 pm-thick polyethylene separator (Entek EP). The cathode used was a lithium intercalation cathode coated on 12 pm-thick aluminum substrate with active cathode material loading of approximately 9-17 mg / cm2 / side of the aluminum substrate.

[0285] The above components were assembled in a stacked three-layer structure of anode / separator / cathode / separator / anode. The total active cathode surface area was 100 cm2. After sealing the cell components in a foil pouch, 0.4-0.5 mL of the appropriate electrolyte was added, whereafter the cell package was vacuum sealed. These cells were allowed to soak in the electrolyte for 24-72 hours unrestrained and then 12 kg / cm2pressure was applied to the cells. All cells went through 4 formation cycles. During the first three cycles, the charge voltage cut-off was 4.35 V and the cells were charged at 30 mA (approximately C / 12), which was tapered down to 3 mA, and then discharged at C / 3 rate. During the fourth cycle, the cells were charged to 4.3 V, with the remaining parameters remaining the same as the first three cycles. Subsequent charge and discharge

[0286] #14755643vlcycling was performed under the following condition unless otherwise noted: C / 3 or 1C charge to 4.3V, followed by taper at 4.3V to 10 mA; 4C / 3 or 4C discharge to 3.2V.

[0287] A summary of the example cells having different electrolyte compositions are given in Table 1 and are described in more detail below. Each cell described in Table 1 was constructed as outlined above, unless otherwise noted. Each cell included a 2 milliinch thick Li metal anode, the same type of lithium intercalation cathode, and was cycled under pressure. Cell 7 in Table 1 included the lithium intercalation cathode in a higher amount than the other tested cells in an attempt to generate more gas during cycling.

[0288] Table 1: Electrolyte composition present in the example Cells.

[0289]

[0290] EXAMPLE 1

[0291] Cells 1-4 from Table 1 are described in this Example. The data show the synergistic combination of prop-l-ene-l,3-sultone (PES), LiBF4, and a fluorinated ether improve cell performance. The cells were prepared as described above. Electrolytes from Cells 1 and 2 both contained a fluorinated cyclic carbonate solvent (FEC) and a unfluorinated linear ester cosolvent (EMC) with a salt: LiPFe. The electrolyte in Cell 2 further comprised a sultone (PES) and LiBF4. Electrolytes in Cells 3 and 4 were similar to electrolytes in Cells 1 and 2, respectively, but each electrolyte in Cells 3 and 4 further comprised an additional fluorinated cosolvent (e.g., a fluorinated ether, HFE). Cells 1

[0292] #14755643vland 3 did not contain the PES and LiBF4. Cells 2 and 4 tested whether the presence of PES and LiBF4 improved cell performance in the absence and presence of a fluorinated cosolvent (e.g., fluorinated ether), respectively.

[0293] FIG. 3 is a plot of discharge capacity as a function of charge-discharge cycle for Cells 1 and 2. FIG. 4 is a plot of the 5-minute discharge resistance as a function of charge-discharge cycle for Cells 1 and 2. Note that the data shown in FIGS. 3 and 4 were collected and are plotted in triplicate. FIGS. 3 and 4 show that the presence of the sultone (PES) and EiBF4 in Cell 2, e.g., the difference between Cells 1 and 2, results in a quick loss of capacity during charge-discharge cycling (FIG. 3) due to a rise in the cell polarization (e.g., resistance) that occurs before charge-discharge cycle 20 (FIG. 4) in Cell 2, relative to Cell 1.

[0294] FIGS. 5 and 6 are similar to the plots shown in FIGS. 3 and 4, but demonstrate data related to Cells 3 and 4. Additionally, note that the data shown in FIGS. 5 and 6 were collected and are plotted in triplicate. FIG. 5 shows that the presence of the sultone (PES) and EiBF4 in Cell 4, e.g., the difference between Cells 3 and 4, results in an improvement in retained capacity as a function of charge-discharge cycle in Cell 4, relative to Cell 3. This is consistent with the data shown in FIG. 6, and therefore demonstrates the polarization buildup in the presence of the sultone (PES) and EiBF4 in Cell 4 is slower than in the absence of the sultone (PES) and EiBF4 in Cell 3. This is a surprising result in view of the data of FIGS. 3 and 4, which show the presence of the sultone (PES) and EiBF4 may be detrimental to cell performance in some instances. That is, as shown in the results gathered using Cell 4, the combination of the sultone (PES), EiBF4, and an additional fluorinated cosolvent (e.g., fluorinated ether, HFE) in the electrolyte of Cell 4 improved the charge-discharge cycling performance of the cell.

[0295] EXAMPLE 2

[0296] Cells 5 and 6 from Table 1 are described in this Example. The data show the addition of PES and LiBF4 to the electrolyte improves cell performance. The cells were prepared as described above. Electrolytes from Cells 5 and 6 both contained a fluorinated cyclic carbonate solvent (FEC), an unfluorinated linear ester cosolvent (EMC), and a fluorinated cosolvent (e.g., a fluorinated ether, HFE). The electrolytes of each cell

[0297] #14755643vlcontain two salts: LiPFe and LiFSI. The electrolyte in Cell 6 further comprised a sultone (PES) and LiBF4.

[0298] FIG. 7 is a plot of discharge capacity as a function of charge-discharge cycle for Cells 5 and 6. FIG. 8 is a plot of the 5-minute discharge resistance as a function of charge-discharge cycle for Cells 5 and 6. Note that the data shown in FIGS. 7 and 8 were collected and are plotted in duplicate. FIG. 7 shows that the presence of the sultone (PES) and LiBF4 in Cell 6, e.g., the difference between Cells 5 and 6, results in an improvement in retained capacity as a function of charge-discharge cycle in Cell 6, relative to Cell 5. The result in FIG. 7 is consistent with the data shown in FIG. 8, which shows the polarization build up in Cell 6 is slower than the build up in Cell 5, which can be attributed to the presence of the sultone (PES) and LiBF4 in Cell 6, e.g., the difference between Cells 5 and 6. The results of FIGS. 7 and 8 further corroborate the results shown in FIGS. 5 and 6 in that the presence of the sultone (PES) and LiBF4 in the electrolyte of a cell improves the cells performance if there is additionally a fluorinated cosolvent (e.g., a fluorinated ether, HFE).

[0299] FIG. 9 is a box plot of the volume of gas generated within the Cells 5 and 6 following the 29thcharge-discharge cycle and storage of the electrochemical cell at 100% state of charge for 60 hours at 72 °C. Each of Cells 5 and 6 were tested in triplicate. The box plot shows the minimum and maximum measured values for each cell, the “x” is the mean, and the midline through the box represents the median. In this case, Cell 6 produced less gas (e.g., reduced thermal gassing) than Cell 5. This again can be attributed to the presence of the sultone (PES) and LiBF4 in Cell 6 compared to Cell 5.

[0300] To add further context to FIG. 9, FIG. 10 shows a similar plot of the volume of gas generated within electrochemical cells following the 29thcharge-discharge cycle and storage of the electrochemical cell at 100% state of charge for 60 hours at 72 °C, but in this case, Cell 7 from Table 1 is analyzed. Gas generation data for variations of Cell 7 where (1) PES is present, (2) LiBF4 is present, and (3) PES and LiBF4 are present is additionally shown in FIG. 10. Each of the cells were tested in triplicate. The box plot shows the minimum and maximum measured values for each cell, the “x” is the mean, and the midline through the box represents the median. FIG. 10 shows that the volume of gas generated by the Cell 7 remains relatively constant despite the addition of PES and / or LiBF4 in the absence of the fluorinated cosolvent (e.g., a fluorinated ether, HFE)

[0301] #14755643vlas in Cell 6, thereby indicating the combination of the PES, LiBF4, and the fluorinated cosolvent (e.g., fluorinated ether, HFE) synergistically improves cell performance.

[0302] EXAMPLE 3

[0303] Cells 8 and 9 from Table 1 are described in this Example. The data show the addition of PES and LiBF4 to the electrolyte improves cell performance. The cells were prepared and cycled as described above. Electrolytes from Cells 8 and 9 both contained a fluorinated cyclic carbonate solvent (FEC), an unfluorinated linear ester cosolvent (DMC), and a fluorinated cosolvent (e.g., a fluorinated ether, TTE). The electrolytes each contain two salts: LiPFe and LiFSI. The electrolyte in Cell 9 further comprised a sultone (PES) and LiBF4.

[0304] FIG. 11 is a plot of discharge capacity as a function of charge-discharge cycle for Cells 8 and 9. A single replicate for Cell 8 is plotted. The data for Cell 9 is plotted in duplicate. FIG. 11 shows that the presence of the sultone (PES) and LiBF4 in Cell 9, e.g., the difference between Cells 8 and 9, result in an improvement in retained capacity as a function of charge-discharge cycle in Cell 9, relative to Cell 8. The result indicates that the presence of the sultone (PES) and LiBF4 in the electrolyte of an electrochemical cell improves the cells performance if there is additionally a fluorinated cosolvent (e.g., a fluorinated ether, TTE).

[0305] EXAMPLE 4

[0306] Cells 10 and 11 from Table 1 are described in this Example. The data show the addition of PES and LiBF4 to the electrolyte improves cell performance. The cells were prepared and cycled as described above. Electrolytes from Cells 10 and 11 both contained a fluorinated cyclic carbonate solvent (FEC), an unfluorinated linear ester cosolvent (DMC), and a fluorinated cosolvent (e.g., a fluorinated ether, HFE). The electrolytes in each cell each contained two salts: LiPFe and LiFSI. The electrolyte in Cell 11 further comprised a sultone (PES) and LiBF4.

[0307] FIG. 12 is a plot of discharge capacity as a function of charge-discharge cycle for Cells 10 and IL A single replicate corresponding to each electrochemical cell is plotted in the figure. FIG. 12 shows that the presence of the sultone (PES) and LiBF4 in Cell 11, e.g., the difference between Cells 10 and 11, result in an improvement in retained

[0308] #14755643vlcapacity as a function of charge-discharge cycle in Cell 11, relative to Cell 10. The result shows that the presence of the sultone (PES) and LiBF4 in the electrolyte of an electrochemical cell improves the cells’ performance if there is additionally a fluorinated cosolvent (e.g., a fluorinated ether, HFE).

[0309] FIG. 13 is a box plot of the volume of gas generated within the Cells 10 and 11 following the 29thcharge-discharge cycle and storage of the electrochemical cell at 100% state of charge for 60 hours at 72 °C. Each of the cells were tested in triplicate. The box plot shows the minimum and maximum measured values for each cell, the “x” is the mean, and the midline through the box represents the median. In this case, Cell 11 produced less gas (e.g., reduced thermal gassing) than Cell 10. This again can be attributed to the presence of the sultone (PES) and LiBF4 in Cell 11 compared to Cell 10.

[0310] EXAMPLE 5

[0311] Cells 12 and 13 from Table 1 are described in this Example. The data show the addition of a fluorinated ether, PES, and LiBF4 to the electrolyte improves cell performance under harsh cycling conditions. The cells were prepared as described above. Electrolytes from Cells 12 and 13 both contained a fluorinated cyclic carbonate solvent (FEC), an unfluorinated linear ester cosolvent (DMC), and a salt: LiPFe. The electrolyte in Cell 12 further comprised a sultone (PES), LiBF4, and a fluorinated cosolvent (e.g., a fluorinated ether, HFE). Cells 12 and 13 were cycled under harsh cycling conditions. Specifically, the cells were cycled through the 4 formation cycles as previously described, with subsequent charge cycles at C / 3 to 10% state of charge (SOC), 3.4C from 10% SOC to 90% SOC, and C / 3 from 90% SOC until reaching a cell voltage of 4.3 V, followed by a tapering down to 10 mA. The charging cycle was followed by discharge at 1C from 4.3 V to 90% SOC, then 3.4C from 90% SOC to a cell voltage 3.2 V, and C / 2 to 3.2 V. Following completion of 45 charge-discharge cycles, the cells were stored at 95% SOC at room temperature for 1 week, and then additional cycles were performed using the same conditions for cycles 5-45. Under similar conditions, conventional electrochemical cells typically produce high surface area lithium.

[0312] FIG. 14 is a plot of discharge capacity as a function of charge-discharge cycle for Cells 12 and 13. FIG. 15 is a plot of the 5-minute discharge resistance as a function of charge-discharge cycle for Cells 12 and 13. The data for each electrochemical cell is

[0313] #14755643vl-H-plotted in triplicate in FIGS. 14 and 15. FIG. 14 shows that the presence of the fluorinated cosolvent (e.g., HFE), sultone (PES), and LiBF4 in Cell 12, e.g., the differences between Cells 12 and 13, result an improvement in retained capacity as a function of charge-discharge cycle in Cell 12, relative to Cell 13. The result in FIG. 14 corresponds to the data shown in FIG. 15, which shows the polarization build up in Cell 12 is slower than the build-up in Cell 13, and can be attributed to the presence of the fluorinated cosolvent (e.g., HFE), sultone (PES), and LiBF4 in Cell 12, e.g., the differences between Cells 12 and 13. The results of FIGS. 14 and 15 further indicate that the presence of the fluorinated cosolvent (e.g., HFE), sultone (PES), and LiBF4 in the electrolyte of an electrochemical cell improves the cells performance under harsh cycling conditions. For instance, the data suggest the formation of an SEI that is more protective to the lithium metal anode, thereby mitigating the formation of high surface area lithium and improving cell performance.

[0314] EXAMPLE 6

[0315] Unless otherwise noted, the electrochemical cells of Examples 7-15 were prepared and tested by using the following materials and methods. Symmetric cells using two substantially identical lithium film electrodes disposed on current collectors were constructed, with the electrode surface area of each electrode being 4.5 cm x 4.191 cm (i.e., approximately 18.9 cm2) and the lithium film being 20 microns thick. The electrodes were assembled in pouch cells with a separator placed between the two electrodes. After assembly, different electrolyte solutions as detailed below were included within the cells.

[0316] The cells were cycled using a charge / discharge current of 8 mA (i.e., a current density of 0.42 mA / cm2). The depth of discharge during cycling was 16%, corresponding to 3.2 microns of the 20-micron thick lithium electrodes participating in the plating / stripping of the electrodes during cycling. Unless otherwise noted, cycling continued until the voltage difference between the electrodes exceeded an absolute value of 2 V (i.e., + / - 2V), indicating lithium depletion from the electrode.

[0317] A summary of the different electrolyte compositions for each of the tested cells is given in Table 2. Each cell described in Table 2 was constructed as outlined above, unless otherwise noted.

[0318] #14755643vlTable 2: Electrolyte composition of Example cells.

[0319]

[0320] #14755643vl

[0321]

[0322] EXAMPLE 7

[0323] Cells 14-17 from Table 2 are described in this Example. The data show the effects of the addition of a PES and / or LiBF4 to an electrolyte containing fluorinated ether (i.e., HFE in this Example). Specifically, the results show the addition of either LiBF4 or PES was detrimental, but the addition of both LiBF4 or PES improved results during cycling. The cells were prepared as described above. Electrolytes from Cells 14-17 each included a fluorinated cyclic carbonate solvent (FEC), an unfluorinated linear ester cosolvent (EMC), a fluorinated ether (HFE), and a salt (LiPFe). The electrolyte in Cell 15 further comprised a sultone (PES). The electrolyte in Cell 16 further comprised LiBF4. The electrolyte in Cell 17 further comprised a sultone (PES) and LiBF4.

[0324] FIG. 16 is a plot of cell voltage as a function of charge-discharge cycle for Cells 14-17. The data for each electrochemical cell is plotted in duplicate. FIG. 16 shows the initial polarization at the first cycle for Cell 15 was higher than for Cells 14, 16, and 17. Additionally, between cycles 10 and 20, an increase of the observed cell voltage was observed in Cells 14 and 16. In contrast, no increase in polarization between cycles 10 and 20 was observed for Cell 17, indicating formation of a favorable SEI. This indicates a synergistic effect between the electrolyte components and the presence of both a sultone (PES) and LiBF4.

[0325] As noted above, the cells were cycled until the voltage difference between the electrodes exceeded an absolute value of 2 V. Cells 15 and 16 exhibited such an increase in cell voltage around cycle 130 and 190, respectively, whereas the voltage exceeded 2V in both Cells 14 and 17 at approximately cycle 200. This again indicates a synergy between the electrolyte components and the presence of both a sultone (PES) and LiBF4.

[0326] The figure of merit (FOM), which is an identification of the lithium reactivity induced polarization, can be calculated in these symmetric lithium cells by the following

[0327] #14755643vlequation: FOM = Depth of Discharge (DOD) * total cycles. Accordingly, the FOM for the best performing Cells 14 and 17 is approximately 31.

[0328] EXAMPLE 8

[0329] Cells 18-21 from Table 2 are described in this Example. The data show the effects of the addition of a PES and / or LiBF4 to an electrolyte absent a fluorinated ether (i.e., HFE in this Example). Specifically, relative to the results in Example 7, the results show the absence of the fluorinated ether was generally detrimental to the formation of an SEI. That is, more lithium was consumed absent the fluorinated ether, generally resulting in an early onset of increased voltage (i.e., lithium depletion). The cells were prepared as described above. Electrolytes from Cells 18-21 each included a fluorinated cyclic carbonate solvent (FEC), an unfluorinated linear ester cosolvent (EMC), and a salt (LiPFe). The electrolyte in Cell 19 further comprised a sultone (PES). The electrolyte in Cell 20 further comprised LiBF4. The electrolyte in Cell 21 further comprised a sultone (PES) and LiBF4.

[0330] FIG. 17 is a plot of cell voltage as a function of charge-discharge cycle for Cells 18-21. The data for each electrochemical cell is plotted in duplicate. Generally, these cells underperformed relative to Cells 14-17. FIG. 17 shows Cells 19 and 21 exhibited a sharp increase in polarization around cycle 25. In contrast, the absence of the sultone (PES) and LiBF4 in Cell 18 and the addition of only LiBF4 in Cell 20 resulted in better performance when compared to Cells 19 and 21, specifically delaying the onset of increased polarization until after 100 cycles. The FOM for Cells 19 and 21 is approximately 4. Comparing Cells 14, 17, 18 and 21, it can be appreciated that the combination of PES and LiBF4 resulted in a synergistic improvement in cycle life in electrolytes comprising a fluorinated ether (as Cell 17 performed better than Cell 14), but decreased cycle life in the absence of a fluorinated ether (as Cell 21 performed worse than Cell 18).

[0331] EXAMPLE 9

[0332] Cells 22-25 from Table 2 are described in this Example. The data show the effects of the addition of a PES and / or LiBF4 to an electrolyte containing fluorinated ether (i.e., HFE in this Example) and LiFSI. Specifically, the results were similar to those

[0333] #14755643vlshown in Example 7, which indicated the addition of both LiBF4 or PES led to the formation of a favorable and more stable SEI. The cells were prepared as described above. Electrolytes from Cells 22-25 each included a fluorinated cyclic carbonate solvent (FEC), an unfluorinated linear ester cosolvent (EMC), a fluorinated ether (HFE), and two salts (LiPFe and LiFSI). The electrolyte in Cell 23 further comprised a sultone (PES). The electrolyte in Cell 24 further comprised LiBF4. The electrolyte in Cell 25 further comprised a sultone (PES) and LiBF4.

[0334] FIG. 18 is a plot of cell voltage as a function of charge-discharge cycle for Cells 22-25. The data for each electrochemical cell is plotted in duplicate. FIG. 18 shows the initial polarization at the first cycle for Cell 23 was higher than for Cells 22, 24, and 25. Additionally, between cycles 10 and 20, an increase of the overpotential was observed in Cells 22 and 24. In contrast, generally no increase in polarization between cycles 10 and 20 was observed for Cells 23 or 25, indicating formation of a favorable SEI. Cell 25 showed the best performance of these cells (i.e., cycle life). Accordingly, this indicates a synergistic effect between electrolyte components and the presence of both a sultone (PES) and LiBF4.

[0335] EXAMPLE 10

[0336] Cells 26-29 from Table 2 are described in this Example. The data show the effects of the addition of a PES and / or LiBF4 to an electrolyte containing LiFSI but absent a fluorinated ether (i.e., HFE in this Example). The cells were prepared as described above. Electrolytes from Cells 26-29 each included a fluorinated cyclic carbonate solvent (FEC), an unfluorinated linear ester cosolvent (EMC), and two salt (LiPFe and LiFSI). The electrolyte in Cell 27 further comprised a sultone (PES). The electrolyte in Cell 28 further comprised LiBF4. The electrolyte in Cell 29 further comprised a sultone (PES) and LiBF4.

[0337] FIG. 19 is a plot of cell voltage as a function of charge-discharge cycle for Cells 26-29. The data for each electrochemical cell is plotted in duplicate. As compared to Cells 19 and 21 in FIG. 17, FIG. 19 shows the presence of LiFSI in Cells 27 and 29 showed a synergistic effect with PES, lowering the lithium consumption and thus extending the lifetime of the cells. In contrast, the addition of the LiFSI had a negative impact on cells containing no additives or only LiBF4 (i.e., compared to Cells 18 and 20

[0338] #14755643vlin FIG. 17), as the cycle lifetime in FIG. 19 for Cells 26 and 28 was approximately 100-120 cycles. This is shorter than the approximately 150 cycle lifetime for Cells 18 and 20 in FIG. 17.

[0339] EXAMPLE 11

[0340] Cells 30-33 from Table 2 are described in this Example. The data show the effects of the low amounts of FEC present in the electrolyte. The cells were prepared as described above. Electrolytes from Cells 30-33 each included a fluorinated cyclic carbonate solvent (FEC), an unfluorinated linear ester cosolvent (EMC), a fluorinated ether (HFE), and a salt (LiPFe). The electrolyte in Cell 31 further comprised a sultone (PES). The electrolyte in Cell 32 further comprised LiBF4. The electrolyte in Cell 33 further comprised a sultone (PES) and LiBF4.

[0341] FIG. 20 is a plot of cell voltage as a function of charge-discharge cycle for Cells 30-33. The data for each electrochemical cell is plotted in triplicate. Generally, the performance of these cells was poor, demonstrating short lifetimes in each case. This was attributed to the presence of the small amount of fluorinated cyclic carbonate (FEC), relative to larger amounts present in Cells 14-29. More specifically, the beneficial effects of the additives (PES and / or LiBF4) and the fluorinated ether (HFE) for forming a favorable SEI was not observed, which was attributed to the low FEC content.

[0342] EXAMPLE 12

[0343] Cells 34-37 from Table 2 are described in this Example. The data show the effects of the low amounts of FEC present in the electrolyte, but also in the presence of LiFSI. The cells were prepared as described above. Electrolytes from Cells 34-37 each included a fluorinated cyclic carbonate solvent (FEC), an unfluorinated linear ester cosolvent (EMC), a fluorinated ether (HFE), and two salts (LiPFe and LiFSI). The electrolyte in Cell 35 further comprised a sultone (PES). The electrolyte in Cell 36 further comprised LiBF4. The electrolyte in Cell 37 further comprised a sultone (PES) and LiBF4.

[0344] FIG. 21 is a plot of cell voltage as a function of charge-discharge cycle for Cells 34-37. The data for each electrochemical cell is plotted in triplicate. Generally, the performance of these cells was poor, demonstrating short lifetimes in each case. Again,

[0345] #14755643vlthis was attributed to the presence of the small amount of fluorinated cyclic carbonate (FEC), relative to larger amounts present in Cells 14-29. However, in Cell 34 it was observed that the presence of LiFSI without the additives (i.e., no PES or LiBF4) improved the SEI formation while reducing lithium consumption, thereby improving cell cycle lifetime, relative to Cell 30 in FIG. 20 that was identical other than lacking LiFSI.

[0346] Again, as in Example 11, the beneficial effects of the additives (PES and / or LiBF4) and the fluorinated ether (HFE) for forming a favorable SEI was not observed, and was attributed to the low FEC content.

[0347] EXAMPLE 13

[0348] Cells 38-41 from Table 2 are described in this Example. The data show the effects of low amounts of FEC and high amounts of HFE present in the electrolyte. The cells were prepared as described above. Electrolytes from Cells 38-41 each included a fluorinated cyclic carbonate solvent (FEC), an unfluorinated linear ester cosolvent (EMC), a fluorinated ether (HFE), and a salt (LiPFe). The electrolyte in Cell 39 further comprised a sultone (PES). The electrolyte in Cell 40 further comprised LiBF4. The electrolyte in Cell 41 further comprised a sultone (PES) and LiBF4.

[0349] FIG. 22 is a plot of cell voltage as a function of charge-discharge cycle for Cells 38-41. The data for each electrochemical cell is plotted in triplicate. Generally, the performance of these cells was poor, demonstrating short lifetimes in each Cell. Again, this was attributed to the presence of the small amount of fluorinated cyclic carbonate (FEC), relative to larger amounts present in Cells 14-29. However, Cells 39-41 exhibited beneficial effects between the additives (PES and / or LiBF4) and the fluorinated ether (HFE) for forming a favorable SEI, with extending cycling lifetime compared to Cell 38 without either additive. The improvements observed in the presence of the additives is attributed to the high HFE content present within the cells, despite the low FEC content.

[0350] EXAMPLE 14

[0351] Cells 42-45 from Table 2 are described in this Example. The data show the effects of low amounts of FEC and high amounts of HFE present in the electrolyte, also in the presence of LiFSI. The cells were prepared as described above. Electrolytes from Cells 42-45 each included a fluorinated cyclic carbonate solvent (FEC), an unfluorinated

[0352] #14755643vllinear ester cosolvent (EMC), a fluorinated ether (HFE), and two salts (LiPFe and LiFSI). The electrolyte in Cell 43 further comprised a sultone (PES). The electrolyte in Cell 44 further comprised LiBF4. The electrolyte in Cell 45 further comprised a sultone (PES) and LiBF4.

[0353] FIG. 23 is a plot of cell voltage as a function of charge-discharge cycle for Cells 42-45. The data for Cells 42 and 43 is plotted in triplicate, whereas the data for Cells 44 and 45 is plotted in duplicate. The addition of LiFSI, relative to the cells in Example 13, resulted in an improved performance in the absence of additives in Cell 42. However, the beneficial effects between the additives (PES and / or LiBF4) and the fluorinated ether (HFE) for forming a favorable SEI was no longer observed in Cells 43-45.

[0354] EXAMPLE 15

[0355] The SEI of Cells 5 and 6 from Table 1 are characterized in this Example. The data show the effects of the presence of the additives in the electrolyte on the resulting SEI formed on both the lithium electrodes and the separators of the cells. The cells were prepared as described above. Electrolytes from Cells 5 and 6 each included a fluorinated cyclic carbonate solvent (FEC), an unfluorinated linear ester cosolvent (EMC), a fluorinated ether (HFE), and two salts (LiPFe and LiFSI). The electrolyte in Cell 6 further included a sultone (PES) and LiBF4. The cells were cycled to form the SEI, whereafter the SEI of each cell was characterized.

[0356] FIG. 24 is an X-ray diffraction (XRD) depth profile of the SEI on each of Cells 5 and 6, which plots the (area of LiF / area of Li2O and LON mixture) versus the incident angle in degrees. The data shows the presence of the PES and LiBF4 additives in the electrolyte of Cell 6 resulted in an SEI having more LiF than that formed in Cell 5 in the absence of the PES and LiBF4 additives. Additionally, the SEI composition varied over the depth of thickness, having more LiF in the outer layer of the SEI in Cell 6 with the PES and LiBF4 additives present.

[0357] FIG. 25A shows an image and corresponding XRD spectrum obtained from the SEI present on the lithium film of Cell 5. FIG. 25B shows an image and corresponding XRD spectrum obtained from the SEI present on the separator of Cell 5. The XRD plot in FIG. 25A is recorded as a function of incident angle of the X-ray source (i.e., from 0.1 to 5 degrees relative from the investigated surface). The peaks associated with the

[0358] #14755643vlunderlying Li in FIG. 25A are indicated as such, and the arrows indicate peaks present due to the SEI. FIG. 25B shows background XRD spectrum of the separator without an SEI, as well as XRD spectrum recorded for the separator with the SEI. Similarly to FIG.

[0359] 25A, the peaks indicated with arrows are present due to the SEI. The XRD spectra of the SEI in each instance was deconvoluted and determined to contain Li, LiF, and LON, whereas Li2O was not identified.

[0360] FIG. 26A shows an image and corresponding XRD spectrum obtained from the SEI present on the lithium film of Cell 6. FIG. 26B shows an image and corresponding XRD spectrum obtained from the SEI present on the separator of Cell 6. The XRD plots in each of FIGS. 26A-26B are recorded as a function of incident angle of the X-ray source (i.e., from 0.1 to 5 degrees relative from the investigated surface). Relative to FIGS. 25A-25B, the new peaks in FIGS. 26A-26B associated with the additives in the XRD spectrum are indicated with arrows. These peaks are associated with differences in the composition of the resulting SEI in the presence and absence of the additives. This difference in SEI composition is associated with the improved cycling performance in the presence of the additives observed in FIG. 7.

[0361] EXAMPLE 16

[0362] A summary of the different electrolyte compositions for each of the cells described in Examples 17 and 18 is given in Table 3. Each cell described in Table 3 was constructed as outlined above, unless otherwise noted.

[0363] Table 3: Electrolyte composition of Example cells.

[0364]

[0365] #14755643vl

[0366]

[0367] EXAMPLE 17

[0368] This Example compares the gas generated by electrochemical cells including Electrolytes 1-4 during thermal storage.

[0369] The electrochemical cells were prepared and tested by using the following materials and methods.

[0370] Cells using 12 micron-thick vapor-deposited lithium electrodes disposed on current collectors were constructed. The cells further included an NCM cathode and a ceramic-coated separator positioned between the lithium electrode and the NCM cathode. After assembly, different localized high-concentration electrolytes as detailed above were included within the cells.

[0371] The cells were sequentially subjected to a formation procedure, degassed, sealed, cycled, and then stored. The formation procedure involved performing four cycles during which the cells were charged at C / 12 to 4.3 V, tapered to 1 / 20 of the charge current, and then discharged at C / 3 to 3.2 V. The cells were cycled 25 times, ending on the 25thcharge, by the following procedure: charging at C / 3 to 4.3 V, tapering to 1 / 20 of the charge current, and then discharging at 4C / 3 to 3.2 V. The cells were then stored at 72 °C for 60 hours. At the conclusion of the storage procedure, the volume of the gas generated was measured.

[0372] The volume of gas generated for each electrochemical cell is shown in FIG. 27. As can be seen from FIG. 27, the electrochemical cells including Electrolytes 1 and 3 generated appreciably more gas than the electrochemical cells including Electrolytes 2 and 4. This indicates that the presence of both PES and LiBF4 in the electrolyte reduced gas generation.

[0373] EXAMPLE 18

[0374] This Example compares the cycling performance of electrochemical cells including Electrolytes 5 and 6.

[0375] The electrochemical cells were prepared and tested by using the following materials and methods.

[0376] #14755643vlCells using 15 micron-thick vapor-deposited lithium electrodes disposed on current collectors were constructed. The cells further included an NCM cathode and a ceramic-coated separator positioned between the lithium electrode and the NCM cathode. After assembly, different localized high-concentration electrolytes as detailed above were included within the cells.

[0377] The cells were sequentially subjected to a formation procedure and then cycled. The formation procedure involved performing four cycles during which the cells were charged at C / 12 to 4.3 V, tapered to 1 / 20 of the charge current, and then discharged at C / 3 to 3.2 V. The cells were then cycled by the following procedure: charging at C / 3 to 4.3 V, tapering to 1 / 20 of the charge current, and then discharging at 4C / 3 to 3.2 V.

[0378] FIG. 28 shows the discharge capacity as a function of cycle life for electrochemical cells including Electrolytes 5 and 6 and FIG. 29 shows the polarization as a function of cycle life for each such electrochemical cell. As can be seen from FIGS.

[0379] 28 and 29, the inclusion of PES and EiBF4 in the cell including Electrolyte 6 resulted in enhanced cycle life and decreased cell polarization. The increased cycle life was particularly surprising because the electrochemical cell including Electrolyte 6 exhibited higher lithium consumption in comparison to the electrochemical cell including Electrolyte 5, indicating that the decreased cell polarization likely resulted in the extended cycle life.

[0380] EXAMPLE 19

[0381] This Example compares the cycling performance of electrochemical cells including Electrolytes 1, 2, 5, and 6.

[0382] The electrochemical cells were prepared as described in Example 18. Their rate capacities were then measured during discharge at 6C and during discharge at C / 2. The ratio of the former to the latter was obtained, and the results are shown in FIG. 30. As can be seen in FIG. 30, in these electrochemical cells, the presence of PES and LiBF4 resulted in relatively higher rate capabilities during discharge at 6C for these electrolytes.

[0383] While several embodiments of the present invention have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and / or structures for performing the functions and / or obtaining the results and / or

[0384] #14755643vlone or more of the advantages described herein, and each of such variations and / or modifications is deemed to be within the scope of the present invention. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and / or configurations will depend upon the specific application or applications for which the teachings of the present invention is / are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the invention may be practiced otherwise than as specifically described and claimed. The present invention is directed to each individual feature, system, article, material, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, and / or methods, if such features, systems, articles, materials, and / or methods are not mutually inconsistent, is included within the scope of the present invention.

[0385] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0386] The phrase “and / or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified unless clearly indicated to the contrary. Thus, as a non-limiting example, a reference to “A and / or B,” when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A without B (optionally including elements other than B); in another embodiment, to B without A (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0387] As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as being inclusive, i.e., the inclusion

[0388] #14755643vlof at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0389] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and / or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0390] As used herein, “wt%” is an abbreviation of weight percentage.

[0391] Some embodiments may be embodied as a method, of which various examples have been described. The acts performed as part of the methods may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include different (e.g., more or less) acts than those that are described, and / or that may involve performing some acts simultaneously, even though the acts are shown as being performed sequentially in the embodiments specifically described above.

[0392] #14755643vlUse of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.

[0393] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

[0394] #14755643vl

Claims

CLAIMSWhat is claimed is:

1. An electrochemical cell, comprising:an electrode comprising lithium metal; anda localized high-concentration electrolyte, wherein the localized high-concentration electrolyte comprises:a coordinating solvent;a non- solvating diluent;a sultone; andLiBF4.

2. A method, comprising:cycling an electrochemical cell, wherein:the electrochemical cell comprises an electrode comprising lithium metal; the electrochemical cell comprises a localized high-concentration electrolyte; andthe localized high-concentration electrolyte comprises a coordinating solvent, a non-solvating diluent, a sultone, and LiBF4.

3. An electrochemical cell, comprising:an electrode comprising lithium metal; andan electrolyte, wherein:the electrolyte comprises a fluorinated cyclic carbonate, an unfluorinated linear ester, and a fluorinated ether,a weight ratio of the fluorinated cyclic carbonate to a combined weight of the unfluorinated linear ester and the fluorinated ether is greater than or equal to 0.25 and less than or equal to 1; anda weight ratio of the unfluorinated linear ester to the fluorinated ether is greater than or equal to 0.25 and less than or equal to 4.

4. An electrochemical cell, comprising:#14755643vlan electrode comprising lithium metal; andan electrolyte, wherein:the electrolyte comprises a fluorinated cyclic carbonate, an unfluorinated linear ester, and a fluorinated sulfonamide,a weight ratio of the fluorinated cyclic carbonate to a combined weight of the unfluorinated linear ester and the fluorinated sulfonamide is greater than or equal to 0.25 and less than or equal to 1; anda weight ratio of the unfluorinated linear ester to the fluorinated sulfonamide is greater than or equal to 0.25 and less than or equal to 4.

5. An electrochemical cell, comprising:an electrode comprising lithium metal; andan electrolyte, wherein:the electrolyte comprises a fluorinated cyclic carbonate, an unfluorinated linear ester, and a fluorinated linear ester,a weight ratio of the fluorinated cyclic carbonate to a combined weight of the unfluorinated linear ester and the fluorinated linear ester is greater than or equal to 0.25 and less than or equal to 1; anda weight ratio of the unfluorinated linear ester to the fluorinated linear ester is greater than or equal to 0.25 and less than or equal to 4.

6. A method, comprising:cycling an electrochemical cell, wherein:the electrochemical cell comprises an electrode comprising lithium metal; the electrochemical cell comprises an electrolyte;the electrolyte comprises a sultone and LiBF4;the electrolyte comprises a fluorinated ether, a fluorinated sulfonamide, and / or a fluorinated ester; andthe cycling is performed under an anisotropic force normal to a surface of the electrode comprising lithium metal.#14755643vl7. An electrochemical cell or method as in any one of the preceding claims, wherein the fluorinated cyclic carbonate and fluorinated ether together make up greater than or equal to 20 wt% and less than or equal to 80 wt% of the electrolyte.

8. An electrochemical cell or method as in any one of the preceding claims, wherein the fluorinated cyclic carbonate and fluorinated ether together make up greater than or equal to 40 wt% and less than or equal to 74 wt% of the electrolyte.

9. An electrochemical cell or method as in any one of the preceding claims, wherein the fluorinated cyclic carbonate and fluorinated sulfonamide together make up greater than or equal to 20 wt% and less than or equal to 80 wt% of the electrolyte.

10. An electrochemical cell or method as in any one of the preceding claims, wherein the fluorinated cyclic carbonate and fluorinated sulfonamide together make up greater than or equal to 40 wt% and less than or equal to 74 wt% of the electrolyte.

11. An electrochemical cell or method as in any one of the preceding claims, wherein the fluorinated cyclic carbonate and fluorinated linear ester together make up greater than or equal to 20 wt% and less than or equal to 80 wt% of the electrolyte.

12. An electrochemical cell or method as in any one of the preceding claims, wherein the fluorinated cyclic carbonate and fluorinated linear ester together make up greater than or equal to 40 wt% and less than or equal to 74 wt% of the electrolyte.

13. An electrochemical cell or method as in any one of the preceding claims, wherein the fluorinated cyclic carbonate comprises fluoroethylene carbonate.

14. An electrochemical cell or method as in any one of the preceding claims, wherein the unfluorinated linear ester is an unfluorinated linear carbonate.#14755643vl15. An electrochemical cell or method as in any one of the preceding claims, wherein the unfluorinated linear carbonate comprises ethylmethyl carbonate, dimethyl carbonate, and / or diethyl carbonate.

16. An electrochemical cell or method as in any one of the preceding claims, wherein the unfluorinated linear ester is a carbonate ester17. An electrochemical cell or method as in any one of the preceding claims, wherein the carbonate ester is methyl acetate, ethyl acetate, n-propyl acetate, z-propyl acetate, n-butyl acetate, z-butyl acetate, methyl propionate, and / or methyl butyrate.

18. An electrochemical cell or method as in any one of the preceding claims, wherein the fluorinated ether comprises 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethylether.

19. An electrochemical cell or method as in any one of the preceding claims, wherein the fluorinated ether comprises l,l,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether.

20. An electrochemical cell or method as in any one of the preceding claims, wherein the fluorinated sulfonamide is a N, N di-alkyl sulfamoyl fluoride and comprises N,N-dimethylsulfamoyl fluoride and / or N,N-diethylsulfamoyl fluoride.

21. An electrochemical cell or method as in any one of the preceding claims, wherein the electrolyte comprises a fluorinated ester.

22. An electrochemical cell or method as in any one of the preceding claims, wherein the fluorinated ester comprises 2,2,2, trifluoroethyl acetate, trifluoroethyl butyrate, and / or trifluoroethyl propionate.

23. An electrochemical cell or method as in any one of the preceding claims, wherein the weight ratio of the fluorinated cyclic carbonate to the combined weight of the unfluorinated linear ester and the fluorinated ether is greater than or equal to 0.5 and less than or equal to 1.#14755643vl24. An electrochemical cell or method as in any one of the preceding claims, wherein the weight ratio of the fluorinated cyclic carbonate to the combined weight of the unfluorinated linear ester and the fluorinated sulfonamide is greater than or equal to 0.5 and less than or equal to 1.

25. An electrochemical cell or method as in any one of the preceding claims, wherein the weight ratio of the fluorinated cyclic carbonate to the combined weight of the unfluorinated linear ester and the fluorinated ester is greater than or equal to 0.5 and less than or equal to 1.

26. An electrochemical cell or method as in any one of the preceding claims, wherein a weight ratio of the fluorinated cyclic carbonate to the unfluorinated linear ester is greater than or equal to 0.3 and less than or equal to 5.

27. An electrochemical cell or method as in any one of the preceding claims, wherein a weight ratio of the fluorinated cyclic carbonate to the fluorinated ether is greater than or equal to 0.3 and less than or equal to 5.

28. An electrochemical cell or method as in any one of the preceding claims, wherein a weight ratio of the fluorinated cyclic carbonate to the fluorinated sulfonamide is greater than or equal to 0.3 and less than or equal to 5.

29. An electrochemical cell or method as in any one of the preceding claims, wherein a weight ratio of the fluorinated cyclic carbonate to the fluorinated ester is greater than or equal to 0.3 and less than or equal to 5.

30. An electrochemical cell or method as in any one of the preceding claims, wherein a weight ratio of the unfluorinated linear ester to the fluorinated ether is greater than or equal to 0.25 and less than or equal to 4.#14755643vl31. An electrochemical cell or method as in any one of the preceding claims, wherein a weight ratio of the unfluorinated linear ester to the fluorinated sulfonamide is greater than or equal to 0.25 and less than or equal to 4.

32. An electrochemical cell or method as in any one of the preceding claims, wherein a weight ratio of the unfluorinated linear ester to the fluorinated ester is greater than or equal to 0.25 and less than or equal to 4.

33. An electrochemical cell or method as in any one of the preceding claims, wherein the electrolyte comprises a sultone.

34. An electrochemical cell or method as in any one of the preceding claims, wherein the sultone is prop-l-ene-l,3-sultone.

35. An electrochemical cell or method as in any one of the preceding claims, wherein the sultone is 1,3-propane sultone.

36. An electrochemical cell or method as in any one of the preceding claims, wherein the electrolyte comprises a salt.

37. An electrochemical cell or method as in any one of the preceding claims, wherein the salt comprises LiBF4.

38. An electrochemical cell or method as in any one of the preceding claims, wherein a weight ratio of the prop-l-ene-l,3-sultone to the LiBF4 is greater than or equal to 0.5 and less than or equal to 2.

39. An electrochemical cell or method as in any one of the preceding claims, wherein the prop-l-ene-l,3-sultone and the LiBF4 together make up greater than or equal to 1 wt% and less than or equal to 10 wt% of the electrolyte.#14755643vl40. An electrochemical cell or method as in any one of the preceding claims, wherein the salt comprises LiPFe.

41. An electrochemical cell or method as in any one of the preceding claims, wherein the salt comprises LiFSI.

42. A method comprising cycling any of the preceding electrochemical cells.

43. A method as in any preceding claim, wherein the cycling is performed under an anisotropic force with a component normal to a surface of the electrode comprising lithium metal.

44. An electrochemical cell or method as in any one of the preceding claims, wherein the electrochemical cell further comprises a second electrode.

45. An electrochemical cell or method as in any one of the preceding claims, wherein the second electrode comprises an NCM cathode.

46. An electrochemical cell or method as in any one of the preceding claims, wherein the second electrode comprises an LFP, LCO, and / or LMFP cathode.

47. An electrochemical cell or method as in any one of the preceding claims, wherein nickel makes up at least 80 wt% of the second electrode.

48. An electrochemical cell or method as in any one of the preceding claims, wherein the electrochemical cell has a figure of merit of greater than or equal to 8, and wherein the figure of merit is equal to a product of a depth of discharge of the electrochemical cell and a cycle life of the electrochemical cell.

49. An electrochemical cell or method as in any one of the preceding claims, wherein the electrical resistance of the electrochemical cell decreases during cycling.#14755643vl50. An electrochemical cell or method as in any one of the preceding claims, wherein, after undergoing 50 cycles, the electrical resistance of the electrochemical cell is at least 20% less than the initial resistance of the electrochemical cell.

51. An electrochemical cell or method as in any one of the preceding claims, wherein, after undergoing 50 cycles, the electrical resistance of the electrochemical cell is at least 50% less than the initial resistance of the electrochemical cell.

52. An electrochemical cell or method as in any one of the preceding claims, wherein an amount of lithium loss per cycle is less than or equal to 0.03 microns.

53. An electrochemical cell or method as in any one of the preceding claims, wherein an amount of lithium loss per Ah is less than or equal to 0.1 micron.

54. An electrochemical cell or method as in any one of the preceding claims, wherein fluorinated solvents make up less than or equal to 70 wt% of the electrolyte.

55. An electrochemical cell or method as in any one of the preceding claims, wherein fluorinated carbonates make up less than or equal to 50 wt% of the electrolyte.

56. An electrochemical cell or method as in any one of the preceding claims, wherein coordinating solvents make up greater than or equal to 10 wt% and less than or equal to 35 wt% of the electrolyte.

57. An electrochemical cell or method as in any one of the preceding claims, wherein unfluorinated ethers make up greater than or equal to 10 wt% and less than or equal to 35 wt% of the electrolyte.

58. An electrochemical cell or method as in any one of the preceding claims, wherein the electrolyte comprises a coordinating solvent.#14755643vl59. An electrochemical cell or method as in any one of the preceding claims, wherein the electrolyte comprises two or more coordinating solvents.

60. An electrochemical cell or method as in any one of the preceding claims, wherein the coordinating solvent is an unfluorinated ether and / or the coordinating solvents comprise one or more unfluorinated ethers.

61. An electrochemical cell or method as in any one of the preceding claims, wherein the coordinating solvent is dimethoxyethane and / or wherein the coordinating solvents comprise dimethoxyethane.

62. An electrochemical cell or method as in any one of the preceding claims, wherein dimethoxyethane makes up greater than or equal to 0 wt% and less than or equal to 25 wt% of the electrolyte.

63. An electrochemical cell or method as in any one of the preceding claims, wherein the coordinating solvent is diethoxyethane and / or wherein the coordinating solvents comprise diethoxyethane.

64. An electrochemical cell or method as in any one of the preceding claims, wherein diethoxyethane makes up greater than or equal to 0 wt% and less than or equal to 25 wt% of the electrolyte.

65. An electrochemical cell or method as in any one of the preceding claims, wherein non-solvating diluents make up greater than or equal to 30 wt% and less than or equal to 70 wt% of the electrolyte.

66. An electrochemical cell or method as in any one of the preceding claims, wherein fluorinated ethers make up greater than or equal to 30 wt% and less than or equal to 70 wt% of the electrolyte.#14755643vl67. An electrochemical cell or method as in any one of the preceding claims, wherein the electrolyte comprises a non-solvating diluent.

68. An electrochemical cell or method as in any one of the preceding claims, wherein the electrolyte comprises two or more non-solvating diluents.

69. An electrochemical cell or method as in any one of the preceding claims, wherein the non-solvating diluent is a fluorinated ether and / or the non-solvating diluents comprise one or more fluorinated ethers.

70. An electrochemical cell or method as in any one of the preceding claims, wherein the non-solvating diluent is l,l,2,2-tetrafhioroethyl-2,2,3,3-tetrafluoropropylether and / or wherein the non-solvating diluents comprise l,l,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether.

71. An electrochemical cell or method as in any one of the preceding claims, wherein 1.1.2.2-tetrafhioroethyl-2,2,3,3-tetrafluoropropylether makes up greater than or equal to 0 wt% and less than or equal to 70 wt% of the electrolyte.

72. An electrochemical cell or method as in any one of the preceding claims, wherein the non-solvating diluent is 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethylether and / or wherein the non-solvating diluents comprise l,l,2,2-tetrafluoroethyl-2,2,2-trifluoroethylether.

73. An electrochemical cell or method as in any one of the preceding claims, wherein 1.1.2.2-tetrafluoroethyl 2,2,2-trifluoroethylether makes up greater than or equal to 0 wt% and less than or equal to 20 wt% of the electrolyte.

74. An electrochemical cell or method as in any one of the preceding claims, wherein the non-solvating diluent is bis(2,2,2-trifluoroethyl)ether and / or the non-solvating diluents comprise bis(2,2,2-trifluoroethyl)ether.#14755643vl75. An electrochemical cell or method as in any one of the preceding claims, wherein bis(2,2,2-trifluoroethyl)ether makes up greater than or equal to 0 wt% and less than or equal to 20 wt% of the electrolyte.

76. An electrochemical cell or method as in any one of the preceding claims, wherein 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethylether and bis(2,2,2-trifluoroethyl)ether together make up greater than or equal to 0 wt% and less than or equal to 20 wt% of the electrolyte.

77. An electrochemical cell or method as in any one of the preceding claims, wherein additives make up greater than or equal to 0.5 wt% and less than or equal to 5 wt% of the electrolyte.

78. The electrochemical cell or method as in any one of the preceding claims, wherein the additives comprise 1,3 propane sultone, 1,4-butane sultone, 1,3,2 dioxathiolane 2,2 dioxide, 1,5,2,4-dioxadithiane 2,2,4,5-tetraoxide, and / or LiBF4.

79. An electrochemical cell or method as in any one of the preceding claims, wherein the sultone makes up greater than or equal to 0.1 wt% and less than or equal to 2 wt% of the electrolyte.

80. An electrochemical cell or method as in any one of the preceding claims, wherein the sultone is prop-l-ene-l,3-sultone.

81. An electrochemical cell or method as in any one of the preceding claims, wherein prop-l-ene-l,3-sultone makes up greater than or equal to 0.1 wt% and less than or equal to 2 wt% of the electrolyte.

82. An electrochemical cell or method as in any one of the preceding claims, wherein LiBF4 makes up greater than or equal to 0.1 wt% and less than or equal to 2 wt% of the electrolyte.#14755643vl83. An electrochemical cell or method as in any one of the preceding claims, wherein the electrolyte comprises LiFSI.

84. An electrochemical cell or method as in any one of the preceding claims, wherein LiFSI makes up greater than or equal to 20 wt% and less than or equal to 40 wt% of the electrolyte.

85. An electrochemical cell or method as in any one of the preceding claims, wherein the electrolyte comprises methylene methanedisulfonate.

86. An electrochemical cell or method as in any one of the preceding claims, wherein methylene methanedisulfonate makes up greater than or equal to 0 wt% and less than or equal to 2 wt% of the electrolyte.#14755643vl

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