Lithium battery electrolyte

Abstract

Aspects of the present disclosure are directed to improving the cycle life and stability of electrochemical cells. Electrolytes and electrochemical cells, including those used in rechargeable lithium batteries, are generally provided. In some embodiments, the electrolytes and electrochemical cells include asymmetric sulfonamides. Also, according to some embodiments, the electrolytes and electrochemical cells include carbonates.

Description

[Technical field]

[0001] Describes electrolytes and electrochemical cells in general, including those used in rechargeable lithium batteries. [Background technology]

[0002] In recent years, there has been much interest in developing high energy density rechargeable Li-ion batteries that use intercalated lithium compounds as cathode active materials. In such cells, current electrolytes are typically based on solutions of lithium salts or carbonate electrolytes. In particular, these electrolytes typically degrade rapidly during repeated charge / discharge cycles. Thus, rechargeable batteries using such electrolytes generally exhibit limited cycle life. Thus, electrochemical cell and electrolyte and / or other improvements to improve cycle life would be beneficial. Summary of the Invention

[0003] Aspects of the present disclosure are directed to improving the cycle life and stability of electrochemical cells. Electrolytes and electrochemical cells, including those used in rechargeable lithium batteries, are generally provided. In some embodiments, the electrolytes and electrochemical cells include asymmetric sulfonamides. The electrolytes and electrochemical cells also include carbonates, according to some embodiments. The subject matter of the present invention includes, 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.

[0004] Some aspects are directed to electrochemical cells. In some embodiments, the electrochemical cell includes a first electrode comprising lithium; a first solvent comprising an asymmetric sulfonamide; and a second solvent, where the second solvent comprises both a cyclic carbonate and a linear carbonate, where the asymmetric sulfonamide has the formula (I): [ka] [In the formula, R 1 and R 2 may be the same or different and each independently represents an unsubstituted, branched or unbranched aliphatic chain; a silyl substituent; or R 1 and R 2 are selected from those which link to form an N-linked heterocycle; R 1 is selected from unsubstituted, branched or unbranched aliphatic chains, R 1 contains n carbon atoms, n being an integer between 1 and 10, R 2 is selected from unsubstituted, branched, or unbranched aliphatic chains, R 2 contains m carbon atoms, m being an integer between 1 and 10, R 1 and R 2 are linked to form an N-linked heterocycle, the N-linked heterocycle contains j carbon atoms, where j is an integer from 2 to 11; R 1 and / or R 2 is a silyl substituent, said silyl substituent is SiR 4 3, R 4 is an unsubstituted, branched or unbranched aliphatic chain containing k carbon atoms, k being an integer between 1 and 10, and R 3 is an electron-withdrawing species.

[0005] Another aspect is directed to an electrochemical cell. In some embodiments, the electrochemical cell includes an electrode comprising lithium; and an asymmetric sulfonamide; wherein the asymmetric sulfonamide has the formula (I): [ka] [In the formula, R 1 and R 2 may be the same or different and each represents an unsubstituted, branched or unbranched aliphatic chain; a silyl substituent; or R 1 and R 2 are selected from those which link to form an N-linked heterocycle; R 1 is selected from unsubstituted, branched or unbranched aliphatic chains, R 1 contains n carbon atoms, n being an integer between 1 and 10, and R 2 is a silyl substituent, R 2 is selected from unsubstituted, branched or unbranched aliphatic chains, R 2 contains m carbon atoms, m being an integer between 1 and 10, and R 1 is a silyl substituent, R 1 and R 2 are linked to form an N-linked heterocycle, the N-linked heterocycle contains j carbon atoms, where j is an integer from 2 to 11; R 1 and / or R 2 is a silyl substituent, said silyl substituent is SiR 4 3, R 4 is an unsubstituted, branched or unbranched aliphatic chain containing k carbon atoms, k being an integer between 1 and 10, and R 3 is an electron-withdrawing species.

[0006] Other advantages and novel features of the present invention will become apparent from the following detailed description of various non-limiting embodiments of the invention when considered in conjunction with the accompanying figures. In the event that the present specification and a document incorporated by reference include conflicting and / or inconsistent disclosure, the present specification shall control. [Brief description of the drawings]

[0007] Non-limiting embodiments of the present invention are illustratively described 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 shown is typically represented by a single numeral. Also, for clarity, not every component is shown in every figure, and not every component of each embodiment of the present invention is shown, unless illustration is necessary for those skilled in the art to understand the invention.

[0008] [Figure 1A] FIG. 1A is a cross-sectional schematic diagram of an exemplary electrochemical cell according to some embodiments. [Figure 1B] FIG. 1B is a cross-sectional schematic diagram of an exemplary electrochemical cell according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] One of the fundamental problems in battery technology is the limited cycle life of rechargeable electrochemical cells. Currently, electrolytes used in lithium intercalation cathode batteries produce cells with limited cycle life. Furthermore, the high reactivity of lithium metal means that lithium-based battery technology often faces problems of thermal runaway and gassing, which can limit the usefulness of these electrochemical cells. The present disclosure is directed to innovative electrochemical cells and electrolytes that can improve the cycle life and stability of batteries, according to some embodiments. In some embodiments, electrolytes including asymmetric sulfonamides, as described below, can advantageously improve the cycle life and stability of electrochemical cells and / or reduce undesirable gassing. In some aspects, novel asymmetric sulfonamides are described. According to some embodiments, the asymmetric sulfonamides perform unexpectedly well when combined with carbonates in the electrolyte of an electrochemical cell.

[0010] The embodiments described herein may be used in connection with electrochemical cells of any suitable type of battery, such as electrochemical cells of lithium-ion or lithium-based batteries (e.g., batteries including a lithium-ion electrode and a lithium metal counter electrode). In some embodiments, the electrochemical cell is a primary (non-rechargeable) battery. In other embodiments, the electrochemical cell is a secondary (rechargeable) battery. Some embodiments relate to lithium rechargeable batteries. Additionally, while embodiments of the present invention are particularly useful for improving the cycle life and stability of electrochemical cells, the embodiments described herein may also be applicable to other applications where an electrolytic solvent is desired.

[0011] The electrochemical cells described herein may include an electrode (e.g., a first electrode). In some embodiments, the electrode (e.g., a first electrode) is an anode, as described in more detail below. In some embodiments, the electrode is a cathode, as described in more detail below. The electrode may include lithium, according to some embodiments (e.g., when the electrode is part of a lithium-ion battery). FIGS. 1A-1B present cross-sectional schematics of an electrochemical cell, according to some embodiments. In FIGS. 1A-1B, electrochemical cells 100 and 101 include an electrode 102, which may include lithium, as well as an optional first current collector 110 and an optional second current collector 112. The electrochemical cell, according to some embodiments, further includes an electrolyte. For example, in FIGS. 1A-1B, electrolyte 104 is present. In some cases, at least a portion of the electrolyte is present in the separator (e.g., the pores of the separator). According to some embodiments, the electrochemical cell includes two electrodes (e.g., a first electrode and a second electrode). For example, in FIG. 1B, electrochemical cell 101 includes a first electrode 102 and a second electrode 108.

[0012] In some embodiments, the optional layer may be disposed proximate (e.g., adjacent) to an electrode. In some embodiments, the optional layer may be disposed between the first electrode and the second electrode. In some embodiments, the optional layer is disposed between the second electrode and the electrolyte. For example, in FIG. 1B, the optional layer 106 is disposed proximate to the second electrode 108, between the first electrode 102 and the second electrode 108, and between the second electrode 108 and the electrolyte 104. In some embodiments, the optional layer includes a protective layer as described herein. Additionally or alternatively, in some embodiments, the optional layer may be a polymer layer (e.g., a separator) that is conductive to or allows the passage of ions, such as lithium ions, as described in more detail below. In some embodiments, there may be two or more optional layers (e.g., two or more protective layers, a protective layer and a separator). Other configurations are possible.

[0013] As mentioned above, the electrochemical cells described herein may include an electrolyte. The electrolyte may function as a medium for the storage and transport of ions, and in the special case of solid and gel electrolytes, these materials may further function as a separator between the first and second electrodes (e.g., anode and cathode). Any liquid, solid, or gel material capable of storing and transporting ions may be used, provided that the material facilitates the transport of ions (e.g., lithium ions) between the first and second electrodes (e.g., anode and cathode). The electrolyte is electronically non-conductive to prevent short circuits between the first and second electrodes. In some embodiments, the electrolyte may include a non-solid electrolyte.

[0014] The electrolytes described herein may include a solvent (e.g., a first solvent). The solvent may be a polar solvent. In some embodiments, the solvent (e.g., a liquid electrolyte solvent) is a non-aqueous solvent. The solvent may include a variety of liquids, including, by way of non-limiting example, sulfonamide-based, ether-based, and / or carbonate-based organic solvents.

[0015] In some embodiments, the solvent (e.g., the first solvent) comprises an asymmetric sulfonamide. For example, in some aspects, the solvent is an asymmetric sulfonamide. According to some embodiments, the asymmetric sulfonamide has the formula (I): [ka] [In the formula, R 1 is selected from unsubstituted, branched or unbranched aliphatic chains, R 1 contains n carbon atoms, n being an integer between 1 and 10, R 2 is selected from unsubstituted, branched, or unbranched aliphatic chains, R 2 contains m carbon atoms, m being an integer between 1 and 10, R 1 and R2 are linked to form an N-linked heterocycle, the N-linked heterocycle contains j carbon atoms, where j is an integer from 2 to 11; R 1 and / or R 2 is a silyl substituent, said silyl substituent is SiR 4 3, R 4 is an unsubstituted, branched or unbranched aliphatic chain containing k carbon atoms, k being an integer between 1 and 10, and R 3 is an electron-withdrawing species.

[0016] In some embodiments, a series of compositions comprising asymmetric sulfonamides are provided. In some embodiments, the series of compositions comprising asymmetric sulfonamides have a formula as described herein (e.g., Formula (I) shown above), where R 1 and R 2 may be the same or different and each represents an unsubstituted, branched or unbranched aliphatic chain; a silyl substituent; or R 1 and R 2 are linked to form an N-linked heterocycle. According to some embodiments of the asymmetric sulfonamides described herein, R 1 and R 2 are the same. In other embodiments of the asymmetric sulfonamides described herein, R 1 and R 2 According to some embodiments, R 1 and R 2 are both unbranched aliphatic chains.

[0017] R 1 In these or other compositions or formulas where R 1 is selected from unsubstituted, branched or unbranched aliphatic chains, R 1contains n carbon atoms, where n is an integer between 1 and 10 (e.g., 2 or more, 4 or more, 6 or more, 8 or more, and / or 8 or less, 6 or less, 4 or less). For example, in some cases, n=1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0018] R 1 In these or other compositions or formulas where R 1 When is a silyl substituent, the silyl substituent may have the form SiR 4 3. R 4 In these or other compositions or formulas where 4 is independently an unsubstituted, branched or unbranched aliphatic chain containing k carbon atoms, where k is an integer between 1 and 10 (e.g., 2 or more, 4 or more, 6 or more, 8 or more, and / or 8 or less, 6 or less, 4 or less). For example, in some cases, k=1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0019] R 2 In these or other compositions or formulas where R 2 is selected from unsubstituted, branched or unbranched aliphatic chains, R 2 contains m carbon atoms, where m is an integer from 1 to 10 (e.g., 2 or more, 4 or more, 6 or more, 8 or more, and / or 8 or less, 6 or less, 4 or less). For example, in some cases, m=1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0020] R 2 In these or other compositions or formulas where R 2 When is a silyl substituent, the silyl substituent may have the form SiR 4 3. R 4 In these or other compositions or formulas where 4is independently an unsubstituted, branched or unbranched aliphatic chain containing k carbon atoms, where k is an integer between 1 and 10 (e.g., 2 or more, 4 or more, 6 or more, 8 or more, and / or 8 or less, 6 or less, 4 or less). For example, in some cases, k=1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0021] For example, in some embodiments, R 1 is a silyl substituent, R 2 is an aliphatic chain or R 2 is a silyl substituent, R 1 is an aliphatic chain. Such examples, according to some embodiments, have the formula (II): [ka]

[0022] In some such embodiments, the asymmetric sulfonamide has a structure according to formula (III): [ka]

[0023] In some embodiments, R 3 is an electron-withdrawing species as described herein. One such example is N-ethyl-N-trimethylsilyltrifluoromethylsulfonamide (Et(MeSi)NSOCF), which is an electron-withdrawing species R 3 is -CF3. The synthesis of this compound is described in Example 1 below.

[0024] In some embodiments, the unsymmetrical sulfonamide has a structure according to formula (IV): [ka] where R (of formula I) 2 As shown, R 1 In some such embodiments, R 1is selected from unsubstituted, branched or unbranched aliphatic chains. Examples include asymmetric sulfonamides having the formula (V): [ka]

[0025] In some embodiments, R 3 is an electron-withdrawing species as described herein. One such example is N,N-dimethylfluorosulfonamide (Me2NSO2F), which has an electron-withdrawing species R 3 is -F. Another example is N,N-dimethyltrifluoromethylsulfonamide (Me2NSO2CF3), in which the electron-withdrawing species R 3 is -CF3. Another embodiment of such an unsymmetrical sulfonamide has the structure shown in formula (VI): [ka]

[0026] For example, N,N-diethyltrifluoromethylsulfonamide (Et2NSO2CF3) is an electron-withdrawing species R 3 is -CF3. R 1 Some embodiments in which is a branched aliphatic chain have a structure according to formula (VII): [ka]

[0027] For example, N,N-diisopropyltrifluoromethylsulfonamide (iPr2NSO2CF3), where the electron-withdrawing species R 3 is -CF3.

[0028] In some embodiments, R 1 and R 2 are different and are each independently selected from an unsubstituted, branched or unbranched aliphatic chain. For example, some asymmetric sulfonamides have the structure shown in formula (VIII): [ka]

[0029] Such examples include N,N-ethylmethyltrifluoromethylsulfonamide (EtMeNSO2CF3), which is an electron-withdrawing species R 3 is -CF3.

[0030] In some embodiments, R 1 and R 2 are different and are each independently selected from an unsubstituted, branched or unbranched aliphatic chain. For example, some asymmetric sulfonamides have the structure shown in formula (IX): [ka]

[0031] Such examples include N,N-ethylmethyltrifluoromethylsulfonamide (EtMeNSO2CF3), which is an electron-withdrawing species R 3 is -CF3.

[0032] R 1 and R 2 In compositions or formulas in which are linked to form an N-linked heterocycle, in some embodiments the N-linked heterocycle comprises j carbon atoms, where j is an integer from 2 to 11 (e.g., 2 or more, 4 or more, 6 or more, 8 or more, and / or 8 or less, 6 or less, 4 or less). For example, in some cases j=2, 3, 4, 5, 6, 7, 8, 9, 10, or 11.

[0033] The N-linked heterocycle may be saturated or unsaturated, according to some embodiments. For example, in some embodiments, the N-linked heterocycle includes one or more double bonds (e.g., along the backbone of the ring). According to some embodiments, the N-linked heterocycle includes an aromatic structure (e.g., a heteroaromatic ring). For example, in some embodiments, the N-linked heterocycle is an N-linked heterocycle. As an example, the N-linked heterocycle has the formula (X), according to some embodiments: [ka]

[0034] In some embodiments, R 3 is an electron-withdrawing species as described herein. In some such embodiments, the electron-withdrawing species R 3 The unsymmetrical sulfonamide pyrrolylperfluorobutylsulfonamide, in which R is -CF, is an integer from 1 to 9. The synthesis of this compound is described in Example 2 below.

[0035] In some embodiments, the N-linked heterocycle contains one or more heteroatoms. For example, the N-linked heterocycle may contain two, three, four, or more heteroatoms. According to some embodiments, the first heteroatom is nitrogen as shown in formula (I). According to some embodiments, the second heteroatom is also a nitrogen atom. For example, according to some embodiments, the N-linked heterocycle has formula (XI): [ka]

[0036] In some embodiments, R 3 is an electron-withdrawing species as described herein. In some such embodiments, the electron-withdrawing species R 3 The synthesis of this compound is described in Example 3 below.

[0037] R 3 In these or other compositions or formulas where R 3 R is an electron withdrawing species. An electron withdrawing species in the context of sulfonamides herein generally refers to a group that draws electrons away from a sulfur atom. For example, a fluorine atom is an electron withdrawing species relative to a sulfur atom. 3 If is an electron-withdrawing species, it may contribute to the polarity of the asymmetric sulfonamide. The electron-withdrawing species described herein may have different polarities and reactivities, as detailed below. The electron-withdrawing species may be charged or uncharged.

[0038] In one embodiment, the electron-withdrawing species included in the asymmetric sulfonamide can be selected from a number of different groups. For example, the electron-withdrawing species incorporated into the asymmetric sulfonamide can include, but is not limited to, halogen atoms (e.g., F, Cl), substituted or unsubstituted, branched or unbranched haloaliphatic (e.g., CF, -CF), -CN, -COOR, -C(=O)R, -CON(R), -CONR, -NO, -SOR, -CH ... 31 , -SO(OR1)2, -SO(OR1)H, -SO1, -SOR 21 , -PO(OR1)2, -PO(OR1)H, protonated amine groups (e.g., -NR3 + and -NH3 + ), or a substituted aromatic group. In some embodiments, the substituted aromatic group may be a halogen atom (e.g., F, Cl), a substituted or unsubstituted, branched or unbranched haloaliphatic (e.g., -CF, -CF), -CN, -COOR, -C(=O)R, -CON(R), -CONR, -NO, -SOR 31 , -SO(OR1)2, -SO(OR1)H, -SO1, -SOR 21 , -PO(OR1)2, -PO(OR1)H, and / or protonated amine groups (e.g., -NR3 + and -NH3 + ).

[0039] Without wishing to be bound by theory, each of the above groups may be R 3 Regardless of the specific functionality of R, R may exhibit electron-withdrawing properties. 3 may be electron-withdrawing or electron-donating, or in some cases, neither electron-withdrawing nor electron-donating.

[0040] The solvent may include other non-aqueous liquid electrolyte solvents. Non-limiting examples of non-aqueous liquid electrolyte solvents include, but are not limited to, non-aqueous organic solvents, such as carbonates (described in more detail below), N-methylacetamide, acetonitrile, acetals, ketals, esters, sulfones, sulfites, sulfolane, aliphatic ethers, cyclic ethers, glymes, polyethers, phosphate esters, siloxanes, dioxolanes (e.g., 1,3-dioxolanes), N-alkylpyrrolidones, bis(trifluoromethanesulfonyl)imides, substituted versions thereof, and blends thereof. Fluorinated derivatives of these are also useful as liquid electrolyte solvents.

[0041] In some embodiments, the electrolyte includes a second solvent (e.g., a co-solvent). In some embodiments, the presence of the second solvent in the electrolyte can improve the properties of the electrochemical cell, such as cycle life, overcharge stability, and / or thermal stability, and / or reduce undesirable behavior, such as gassing during cycling. Without wishing to be bound by theory, the presence of the second solvent (e.g., a co-solvent) can improve the solubility of species (e.g., salts) in the electrolyte. In some embodiments, the second solvent is a polar solvent. However, it should be understood that in some embodiments, the first solvent and / or the second solvent may be, independently, a polar solvent or a non-polar solvent.

[0042] According to some embodiments, the second solvent comprises a carbonate. In some embodiments, the carbonate is a linear carbonate. In some embodiments, the carbonate is a cyclic carbonate. According to some embodiments, the second solvent comprises one or more carbonates. For example, according to certain embodiments, the second solvent comprises a first carbonate and a second carbonate. In the context of the present disclosure, it is inventively recognized that in some embodiments, the presence of both a cyclic carbonate and a linear carbonate in the electrolyte can unexpectedly improve the properties of the electrochemical cell, as described in more detail below. However, in other embodiments, the second solvent is absent or does not comprise a carbonate. In some embodiments, the second solvent can comprise another (e.g., carbonate-free) non-aqueous solvent, as described herein.

[0043] In some embodiments, the first carbonate is a linear carbonate and the second carbonate is a cyclic carbonate. For example, the second solvent may include a mixture of dimethyl carbonate (linear carbonate) and fluoroethylene carbonate (cyclic carbonate). In some embodiments, the first carbonate is a cyclic carbonate and the second carbonate is a linear carbonate. The first carbonate and the second carbonate may also be of the same type. For example, in some embodiments, the second solvent includes one or more linear carbonates. In some embodiments, the second solvent includes one or more cyclic carbonates. Additional combinations including two or more carbonates are also possible.

[0044] In some embodiments, an electrochemical cell comprising a first solvent comprising an unsymmetrical sulfonamide (e.g., an unsymmetrical sulfonamide having any one of Formulas I-XI) and a second solvent comprising one or more carbonates (e.g., linear carbonates and / or cyclic carbonates) may advantageously increase the cycle life, overcharge stability, and / or thermal stability of the electrochemical cell, as described in more detail below.

[0045] In some embodiments, the carbonate (e.g., the first carbonate) is a linear carbonate. The linear carbonate, according to some embodiments, has the chemical structure (XII): [ka] [In the formula, R 5 and R 6 may 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 containing 1 to 10 carbon atoms (e.g., 2 or more, 4 or more, 6 or more, 8 or more, and / or 10 or less, 8 or less, 6 or less, 4 or less). For example, in some cases, R 5 contains 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. 6 , 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. For example, the carbonate may be dimethyl carbonate or ethyl methyl carbonate.

[0046] In some embodiments, the carbonate (e.g., the second carbonate) is a cyclic carbonate. The cyclic carbonate, according to some embodiments, has the chemical structure (XIII): [ka] [In the formula, R 7 is a heterocyclic ring formed by linking two oxygen atoms and is selected from unsubstituted unbranched aliphatic; substituted or unsubstituted unbranched haloaliphatic; or substituted or unsubstituted unbranched haloheteroaliphatic chains containing 1 to 10 carbon atoms (e.g., 2 or more, 4 or more, 6 or more, 8 or more, and / or 10 or less, 8 or less, 6 or less, 4 or less). For example, in some cases, R 7, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. For example, the cyclic carbonate may be fluoroethylene carbonate.

[0047] According to some embodiments, the solvents (e.g., the first solvent and the second solvent) form part of the electrolyte. In some embodiments, the solvents form, in total, 10 wt% or more, 20 wt% or more, 30 wt% or more, 40 wt% or more, 50 wt% or more, 60 wt% or more, 70 wt% or more, 80 wt% or more, 90 wt% or more, 95 wt% or more of the electrolyte. In some embodiments, the solvents form, in total, 99 wt% or less, 95 wt% or less, 90 wt% or less, 80 wt% or less, 70 wt% or less, 60 wt% or less, 50 wt% or less, 40 wt% or less, or less. Combinations of these ranges are also possible. For example, according to some embodiments, the solvents form, in total, 10 wt% or more and 99 wt% or less of the electrolyte. As another example, according to some embodiments, the solvents form, in total, 30 wt% or more and 70 wt% or less of the electrolyte.

[0048] In the context of the present disclosure, it has been inventively recognized that, in some embodiments, an electrochemical cell in which a first solvent comprises an asymmetric sulfonamide and a second solvent comprises both a cyclic carbonate and a linear carbonate has unexpected advantages over electrochemical cells that comprise only linear carbonates and / or cyclic carbonates. These advantages include, according to some embodiments, higher cycle life, higher overcharge stability, higher thermal stability, and / or reduced gassing, as compared to cells having electrolytes that do not comprise an asymmetric sulfonamide, a linear carbonate, and a cyclic carbonate.

[0049] In some such embodiments, the molar ratio of linear carbonate to cyclic carbonate is 0:1 or more, 1:10 or more, 1:9 or more, 1:8 or more, 1:7 or more, 1:5 or more, 1:4 or more, 1:3 or more, 1:2 or more, 1:1 or more, 2:1 or more, 3:1 or more, 4:1 or more, 5:1 or more, 6:1 or more, or 10:1 or more. In some such embodiments, the molar ratio of linear carbonate to cyclic carbonate is 20:1 or less, 10:1 or less, 6:1 or less, 5:1 or less, 4:1 or less, 3:1 or less, 2:1 or less, 1:1 or less, 1:2 or less, 1:3 or less, 1:4 or less, 1:5 or less, 1:7 or less, 1:8 or less, 1:9 or less, 1:10 or less. Combinations of the above ranges are also possible. For example, the molar ratio of linear carbonate to cyclic carbonate in the second solvent may be from 0:1 to 20:1 in some embodiments. As another example, the molar ratio of linear carbonate to cyclic carbonate may be from 1:6 to 1:3 in some embodiments. Other compositions of organic solvents are possible.

[0050] In some embodiments in which both carbonate and asymmetric sulfonamide are present, the molar ratio between the carbonate and asymmetric sulfonamide is 0:1 or more, 1:10 or more, 1:9 or more, 1:8 or more, 1:7 or more, 1:5 or more, 1:4 or more, 1:3 or more, 1:2 or more, 1:1 or more, 2:1 or more, 3:1 or more, 4:1 or more, 5:1 or more, 6:1 or more, 10:1 or more. In some such embodiments, the molar ratio between the carbonate and asymmetric sulfonamide is 20:1 or less, 10:1 or less, 6:1 or less, 5:1 or less, 4:1 or less, 3:1 or less, 2:1 or less, 1:1 or less, 1:2 or less, 1:3 or less, 1:4 or less, 1:5 or less, 1:7 or less, 1:8 or less, 1:9 or less, 1:10 or less. Combinations of the above ranges are also possible. For example, the molar ratio between the carbonate and the asymmetric sulfonamide in the electrochemical cell may be 0:1 or more and 20:1 or less, according to some embodiments. In some embodiments, the carbonate is a linear carbonate. In some embodiments, the carbonate is a cyclic carbonate. In some embodiments, the carbonate is a combination of linear and cyclic carbonates (e.g., the carbonate is the total amount of carbonate including linear and cyclic carbonates in the molar ratios described above). In some embodiments in which both linear and cyclic carbonates are present, each type of carbonate may be independently present in one or more of the molar ratios described above with respect to the asymmetric sulfonamide. Other compositions of organic solvents are possible.

[0051] In some embodiments, electrochemical cells comprising the asymmetric sulfonamides and carbonates (e.g., linear carbonates, cyclic carbonates) described herein exhibit improved cycle life as compared to other equivalent electrochemical cells that do not contain both the asymmetric sulfonamides and carbonates. In some embodiments, electrochemical cells comprising the asymmetric sulfonamides, linear carbonates, and cyclic carbonates described herein exhibit improved cycle life as compared to other equivalent electrochemical cells that do not contain both the asymmetric sulfonamides, linear carbonates, and cyclic carbonates.

[0052] In some embodiments, electrochemical cells comprising the asymmetric sulfonamides and carbonates described herein exhibit cycle lives that are 1.2 times or more, 1.5 times or more, 1.7 times or more, 2 times or more, 3 times or more, 5 times or more, 10 times or more, 15 times or more, 20 times or more, 25 times or more, 30 times or more, or 40 times or more. In some embodiments, electrochemical cells comprising the asymmetric sulfonamides and carbonates described herein exhibit cycle lives that are 50 times or less, 40 times or less, 30 times or less, 20 times or less, 10 times or less, or 3 times or less than the cycle life of an otherwise equivalent electrochemical cell that does not include the asymmetric sulfonamides and / or carbonates. Combinations of the above ranges are also possible (e.g., 1.2 times or more, 50 times or less). Other ranges are also possible.

[0053] In some embodiments, electrochemical cells comprising the asymmetric sulfonamides, linear carbonates, and cyclic carbonates described herein exhibit cycle lives that are 1.2 or more, 1.5 or more, 1.7 times, 2 times or more, 3 times or more, 5 times or more, 10 times or more, 15 times or more, 20 times or more, 25 times or more, 30 times or more, or 40 times or more. In some embodiments, electrochemical cells comprising the asymmetric sulfonamides, linear carbonates, and cyclic carbonates exhibit cycle lives that are 50 or less, 40 or less, 30 or less, 20 or less, 10 or less, or 3 or less than the cycle life of an otherwise equivalent electrochemical cell that does not include one or more or all of the asymmetric sulfonamides, linear carbonates, and cyclic carbonates. Combinations of the above ranges are also possible (e.g., 1.2 times or more and 50 times or less). Other ranges are also possible.

[0054] In some embodiments, the solvents described herein can be incorporated into gel polymer electrolytes. Liquid electrolyte solvents are useful as plasticizers for gel polymer electrolytes, i.e., electrolytes that include one or more polymers that form a semi-solid network. Examples of useful gel polymer electrolytes include, but are not limited to, those that include one or more polymers selected from polyethylene oxide, polypropylene oxide, polyacrylonitrile, polysiloxane, polyimide, polyphosphazene, polyether, sulfonated polyimide, perfluorinated membranes (NAFION resins), polydivinyl polyethylene glycol, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polysulfone, polyethersulfone, derivatives thereof, copolymers thereof, crosslinked and network structures thereof, and blends thereof, and optionally one or more plasticizers. In some embodiments, the gel polymer electrolyte includes 10-20%, 20-40%, 60-70%, 70-80%, 80-90%, or 90-95% by volume of liquid electrolyte.

[0055] In some embodiments, one or more solid polymers can be used to form the electrolyte. Examples of useful solid polymer electrolytes include, but are not limited to, those that include one or more polymers selected from polyethers, polyethylene oxides, polypropylene oxides, polyimides, polyphosphazenes, polyacrylonitriles, polysiloxanes, derivatives thereof, copolymers thereof, crosslinked structures and network structures of the above, and blends of the above.

[0056] In some embodiments, an electrochemical cell includes a first electrode comprising lithium; a first solvent comprising an asymmetric sulfonamide; and a second solvent, where the second solvent comprises both a cyclic carbonate and a linear carbonate, and the asymmetric sulfonamide has the formula (I), where R 1 and R 2 may be the same or different and each independently represents an unsubstituted, branched or unbranched aliphatic chain, a silyl substituent, or R1 and R 2 are selected from those which join to form an N-linked heterocycle, where R 1 is selected from unsubstituted, branched or unbranched aliphatic chains, R 1 contains n carbon atoms, n being an integer between 1 and 10, R 2 is selected from unsubstituted, branched or unbranched aliphatic chains, R 2 contains m carbon atoms, m being an integer between 1 and 10, 1 and R 2 are linked to form an N-linked heterocycle, the N-linked heterocycle contains j carbon atoms, j being an integer between 2 and 11, inclusive, where R 1 and / or R 2 is a silyl substituent, the silyl substituent is SiR 4 3, where R 4 is an unsubstituted, branched or unbranched aliphatic chain containing k carbon atoms, where k is an integer between 1 and 10; and 3 is an electron-withdrawing species.

[0057] In some embodiments, an electrochemical cell includes a first electrode comprising lithium; and an asymmetric sulfonamide, where the asymmetric sulfonamide has the formula (I); where R 1 and R 2 may be the same or different and each represents an unsubstituted, branched or unbranched aliphatic chain, a silyl substituent, or R 1 and R 2 are selected from those which join to form an N-linked heterocycle, where R 1 is selected from unsubstituted, branched or unbranched aliphatic chains, R 1 contains n carbon atoms, n being an integer between 1 and 10, R 2 is a silyl substituent; R 2 is selected from unsubstituted, branched or unbranched aliphatic chains, R 2 contains m carbon atoms, m being an integer between 1 and 10, 1is a silyl substituent; R 1 and R 2 when R are linked to form an N-linked heterocycle, the N-linked heterocycle contains j carbon atoms, j being an integer from 2 to 11; 1 and / or R 2 is a silyl substituent, the silyl substituent is SiR 4 3, where R 4 is an unsubstituted, branched or unbranched aliphatic chain containing k carbon atoms, where k is an integer between 1 and 10; and 3 is an electron-withdrawing species. In some embodiments, the second solvent comprises both cyclic and linear carbonates.

[0058] In some embodiments described above and herein, the molar ratio between the linear carbonate and the cyclic carbonate is 1:6 to 1:3. 1 and R 2 and are both unbranched aliphatic chains. In some embodiments described above and herein, the electrochemical cell may further include a second electrode. In some embodiments, the second electrode may be a lithium intercalation electrode. In some embodiments, R 1 and R 2 are linked to form an N-linked heterocycle. 1 and / or R 2 is a silyl substituent. In some embodiments, electrochemical cells comprising asymmetric sulfonamides exhibit improved cycle life. As used herein, the cycle life of an electrochemical cell is the number of charge-discharge cycles that an electrochemical cell can undergo before its capacity falls below a threshold value. The threshold value may be any suitable percentage of the initial charge of the electrochemical cell. For example, according to some embodiments, the cycle life of an electrochemical cell is the number of charge-discharge cycles that an electrochemical cell can undergo before its capacity falls below 90%, 80%, 70%, 60%, 57%, 55%, 50%, or 25% of its initial capacity.

[0059] In some embodiments, electrochemical cells comprising the asymmetric sulfonamides described herein exhibit cycle lives of 100 or more, 150 or more, 200 or more, 250 or more, 300 or more, 350 or more, 400 or more, 450 or more, 500 or more, 600 or more, 700 or more, 800 or more, 900 or more, 1000 or more, 1100 or more, 1200 or more, 1300 or more, 1500 or more, 2000 or more. In some embodiments, the electrochemical cells comprising the asymmetric sulfonamides described herein exhibit a cycle life of 5000 cycles or less, 4000 cycles or less, 3000 cycles or less, 2000 cycles or less, 1500 cycles or less, 1400 cycles or less, 1300 cycles or less, 1200 cycles or less, 1100 cycles or less, 1000 cycles or less, 900 cycles or less, 800 cycles or less, 700 cycles or less, 600 cycles or less, or about 500 cycles or less. Combinations of the above ranges are possible. For example, in some embodiments, the electrochemical cells comprising the asymmetric sulfonamides described herein exhibit a cycle life of 100 to 5000 cycles before their capacity falls below 60%. As another example, in some embodiments, the electrochemical cells comprising the asymmetric sulfonamides described herein exhibit a cycle life of 400 to 1500 cycles before their capacity falls below 57%. Other ranges are possible.

[0060] In some embodiments, electrochemical cells comprising asymmetric sulfonamides as described herein exhibit improved cycle life (all other factors being equal) compared to an otherwise equivalent electrochemical cell that does not comprise an asymmetric sulfonamide. In some embodiments, electrochemical cells comprising asymmetric sulfonamides as described herein exhibit cycle life that is 1.2 times or more, 1.5 times or more, 1.7 times or more, 2 times or more, 3 times or more, 5 times or more, 10 times or more, 15 times or more, 20 times or more, 25 times or more, 30 times or more, or 40 times or more than the cycle life of an otherwise equivalent electrochemical cell that does not comprise an asymmetric sulfonamide. In some embodiments, electrochemical cells comprising asymmetric sulfonamides as described herein exhibit cycle life that is 50 times or less, 40 times or less, 30 times or less, 20 times or less, 10 times or less, or 3 times or less than the cycle life of an otherwise equivalent electrochemical cell that does not comprise an asymmetric sulfonamide. Combinations of the above ranges are also possible (e.g., 1.2 times or more, 50 times or less). Other ranges are also possible.

[0061] A commonly considered feature in the design of batteries (such as lithium batteries) is overcharge stability. During overcharge, electrochemical cells often experience gassing, as described in more detail below. In the overcharged state, the electrochemical cell maintains a high voltage (overcharge voltage) and the temperature increases. During overcharge, electrochemical cells often experience gassing. High overcharge stability, as indicated by a higher overcharge voltage and / or a lower maximum observed temperature during overcharge, is advantageous for electrochemical cells according to some embodiments, as these characteristics make the electrochemical cell safer and more stable during normal use.

[0062] According to some embodiments, the electrochemical cell comprising the asymmetric sulfonamide has a higher overcharge voltage than the electrochemical cell not comprising the asymmetric sulfonamide. According to some embodiments, the electrochemical cell comprising the asymmetric sulfonamide has an overcharge voltage of 12V or more, 13V or more, 14V or more, 15V or more, 15.5V or more. According to some embodiments, the electrochemical cell comprising the asymmetric sulfonamide has an overcharge voltage of 20V or less, 18V or less, 17V or less, 16V or less, 15.5V or less, 15V or less, 14V or less, 13V or less, or less. Combinations of these ranges are also possible. For example, according to some embodiments, the electrochemical cell comprising the asymmetric sulfonamide has an overcharge voltage of 12V or more and 20V or less.

[0063] According to some embodiments, the electrochemical cell has a maximum observed temperature during overcharge of 150° C. or less, 120° C. or less, 102° C. or less, 100° C. or less, 98° C. or less, 95° C. or less, or 92° C. or less. According to some embodiments, the electrochemical cell has a maximum observed temperature during overcharge of 30° C. or more, 40° C. or more, or 50° C. or more. Combinations of these ranges are also possible. For example, according to some embodiments, the electrochemical cell has a maximum observed temperature during overcharge of 30° C. or more and 150° C. or less.

[0064] A particular problem with lithium batteries is thermal runaway, which is observed at high temperatures, e.g. 150-230 °C, and leads to the complete destruction of the battery. To prevent such thermal runaway, various methods have been proposed, such as coating the electrodes with polymers. However, these methods usually lead to a dramatic decrease in capacity. The decrease in capacity is due in particular to the formation of lithium dendrites during charging, volume changes during charging and discharging, etc.

[0065] In some embodiments, the electrochemical cells described herein can be cycled at relatively high temperatures without experiencing thermal runaway. The term "thermal runaway" is understood by those skilled in the art and refers to a situation in which an electrochemical cell cannot dissipate heat generated during charging and discharging fast enough to prevent uncontrollable temperature rise in the cell. Often, a positive feedback loop occurs during thermal runaway (e.g., the electrochemical reaction generates heat, which increases the rate of the electrochemical reaction, leading to further heat generation), and the electrochemical cell may catch fire. In some embodiments, the electrolyte (e.g., the composition of the electrolyte, which may include the asymmetric sulfonamide) can be configured such that thermal runaway is not observed at the relatively high operating temperature of the electrochemical cell. In some embodiments, this is related to the thermal stability and / or non-flammability of the asymmetric sulfonamide at high temperatures.

[0066] In some embodiments, the electrolyte can be configured to allow the electrochemical cell to operate (e.g., continuously charge and discharge) at temperatures up to about 130° C., up to about 150° C., up to about 170° C., up to about 190° C., up to about 200° C., up to about 205° C., up to about 210° C., up to about 215° C., or up to about 230° C. (e.g., as measured at an exterior surface of the electrochemical cell) without the electrochemical cell experiencing thermal runaway. In some embodiments, the electrochemical cell can be operated at any of the above temperatures without catching fire. In some embodiments, the electrochemical cells described herein can be operated at relatively high temperatures (e.g., any of the above temperatures) without experiencing thermal runaway and without employing auxiliary cooling mechanisms (e.g., heat exchangers external to the electrochemical cell, active fluid cooling external to the electrochemical cell, etc.).

[0067] In some existing systems, electrolyte degradation can result in the generation of gaseous by-products, also known as gassing. Gassing in electrochemical cells is usually at least partially dependent on the electrolyte composition. Without wishing to be bound by theory, gassing electrochemical cells are often believed to occur as a result of oxidation of the electrolyte on the cathode side of the electrochemical cell.

[0068] As described herein, the use of asymmetric sulfonamides in electrolyte solutions may reduce gas generation during operation of electrochemical cells compared to electrochemical cells that do not contain asymmetric sulfonamides. In some embodiments, the amount of gas formed by electrochemical cells that contain asymmetric sulfonamides is reduced by 5% or more, 8% or more, 10% or more, 13% or more, 14% or more, all other factors being equal, compared to electrochemical cells that do not contain asymmetric sulfonamides. The electrolytes described herein may reduce the number of gases generated by electrochemical cells (e.g., in lithium-based batteries) compared to electrochemical cells that do not contain these electrolytes. In some embodiments, reduced gas generation is associated with the lower reactivity of asymmetric sulfonamides with electroactive materials (e.g., lithium metal).

[0069] The amount (e.g., volume) of gaseous products produced in the electrochemical cell can be determined using a fluid displacement method, in which the volume of water displaced by the battery before cycling is compared to the volume of water displaced by the battery after cycling, and the volume difference is assumed to be equal to the volume of gas produced during cycling. This method was used to calculate the gas generation amount, as described in more detail in Example 4. One advantage of this method is that the volume of the electrochemical cell (e.g., before cycling, after cycling) can be determined without opening the electrochemical cell (e.g., assembled electrochemical cell, closed electrochemical cell), and can be used to determine the volume of the electrochemical cell and the volume of the gaseous products produced.

[0070] In some embodiments, the electrolyte comprises a fluid electrolyte (e.g., liquid) that can be added at any suitable time in the manufacturing process. In some cases, the electrochemical cell is made by providing a first electrode and a second electrode (e.g., an anode and a cathode), applying a component of anisotropic force perpendicular to the active surface of the first electrode and / or the second electrode, and then adding a fluid electrolyte such that the electrolyte is in electrochemical communication with the first electrode and the second electrode (e.g., the anode and the cathode). In other aspects, the fluid electrolyte is added to the electrochemical cell before or simultaneously with the application of the component of the anisotropic force, and then the electrolyte is in electrochemical communication with the first electrode and the second electrode (e.g., the anode and the cathode). In some embodiments, the fluid electrolyte is added to the electrochemical cell without the application of an anisotropic force, and then the anisotropic force is not applied.

[0071] According to some embodiments, the electrolyte comprises a salt (e.g., a lithium salt). Examples of electrolyte salts for use in the electrochemical devices described herein (e.g., the electrochemical cells described herein) include, but are not limited to, lithium bis(fluorosulfonyl)imide (LiSCN), LiBr, LiI, lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), LiSO3CF3, LiSO3CH3, lithium tetrafluoroborate (LiBF4), LiB(Ph)4, lithium hexafluorophosphate (LiPF6), lithium trifluoromethanesulfonate (LiCF3SO3), LiC(SO2CF3)3, lithium bis(trifluoromethanesulfonyl)imide (LiN(SO2CF3)2), and lithium bis(fluorosulfonyl)imide (LiFSI). Other electrolyte salts that may be useful include lithium polysulfide (Li2S x ), and lithium salts of organic polysulfides (LiS x R) nwhere x is an integer from 1 to 20, n is an integer from 1 to 3, and R is an organic group, including those disclosed in U.S. Pat. No. 5,538,812 to Lee et al., which is incorporated by reference in its entirety for all purposes.

[0072] In some embodiments, the electrolyte comprises one or more room temperature ionic liquids. Room temperature ionic liquids, when present, typically comprise one or more cations and one or more anions. Non-limiting examples of suitable cations include lithium cations and / or one or more quaternary ammonium cations, such as imidazolium cations, pyrrolidinium cations, pyridinium cations, tetraalkylammonium cations, pyrazolium cations, piperidinium cations, pyridazinium cations, pyrimidinium cations, pyrazinium cations, oxazolium cations, and trizolium cations. Non-limiting examples of suitable anions include trifluoromethylsulfonate (CF3SO3 - ), bis(fluorosulfonyl)imide (N(FSO2)2 - , bis(trifluoromethylsulfonyl)imide ((CF3SO2)N2 - , bis(perfluoroethylsulfonyl)imide ((CF3CF2SO2)N2 - and tris(trifluoromethylsulfonyl)methide ((CF3SO2)C3 - Non-limiting examples of suitable ionic liquids include N-methyl-N-propylpyrrolidinium / bis(fluorosulfonyl)imide and 1,2-dimethyl-3-propylimidazolium / bis(trifluoromethanesulfonyl)imide. In some embodiments, the electrolyte comprises both a room temperature ionic liquid and a lithium salt. In other embodiments, the electrolyte comprises a room temperature ionic liquid and does not comprise a lithium salt.

[0073] According to some embodiments, the salt forms part of the electrolyte. In some embodiments, the salt forms 2 wt% or more, 5 wt% or more, 10 wt% or more, 15 wt% or more, 20 wt% or more, 30 wt% or more, 40 wt% or more of the electrolyte. In some embodiments, the salt forms 80 wt% or less, 70 wt% or less, 60 wt% or less, 50 wt% or less, 40 wt% or less, 30 wt% or less, 20 wt% or less, 15 wt% or less, 10 wt% or less, 5 wt% or less of the electrolyte. Combinations of these ranges are also possible. For example, according to some embodiments, the salt forms 80 wt% or more and 5 wt% or less of the electrolyte.

[0074] The electrolyte may include one or more ionic electrolyte salts to provide ionic conductivity and one or more liquid electrolyte solvents, gel polymer materials, or polymer materials. Suitable non-aqueous electrolytes may include organic electrolytes including one or more materials selected from the group consisting of liquid electrolytes, gel polymer electrolytes, and solid polymer electrolytes. Examples of non-aqueous electrolytes for lithium batteries are described by Dorniney in Lithium Batteries, New Materials, Developments and Perspectives, Chapter 4, pp. 137-165, Elsevier, Amsterdam (1994). Examples of gel polymer electrolytes and solid polymer electrolytes are described by Alamgir et al. in Lithium Batteries, New Materials, Developments and Perspectives, Chapter 3, pp. 93-136, Elsevier, Amsterdam (1994). Liquid electrolyte compositions that can be used in the batteries described herein are described in U.S. patent application Ser. No. 12 / 312,764, entitled "Separation of Electrolytes," by Mikhaylik et al., filed May 26, 2009, which is hereby incorporated by reference in its entirety.

[0075] A variety of materials can be used as the second electrode (e.g., second electrode 108 of FIG. 1B) in the electrochemical cells described herein. For example, the second electrode (e.g., anode) can include a lithium-containing material, with lithium being the electroactive material. Suitable electroactive materials (e.g., for use as the anode active material in the second electrodes described herein) include, but are not limited to, lithium metal, such as lithium foil or lithium deposited on a conductive substrate, and lithium alloys (e.g., lithium-aluminum alloys and lithium-tin alloys). Methods for depositing the negative electrode material (e.g., an alkali metal, such as lithium) on a substrate include methods such as thermal evaporation, sputtering, jet deposition, laser ablation, and the like. Alternatively, when the second electrode includes lithium foil, or a lithium foil and a substrate, they can be laminated together to form an electrode by a lamination process as known in the art.

[0076] In some embodiments, the second electrode (e.g., anode) is an electrode where lithium ions are released during discharge and integrated (e.g., intercalated) during charging. In some embodiments, the anode active material is a lithium intercalation compound (e.g., a compound that can reversibly insert lithium ions into lattice sites and / or interstitial sites). In some embodiments, the anode active material includes carbon. In some embodiments, the anode active material is or includes a graphitic material (e.g., graphite). A graphitic material generally refers to a material that includes multiple layers of graphene (i.e., layers that include carbon atoms covalently bonded in a hexagonal lattice). Adjacent graphene layers are typically attracted to each other via van der Waals forces, although in some cases there may be covalent bonds between one or more sheets. In some embodiments, the carbon-containing anode active material is or includes coke (e.g., petroleum coke). In some embodiments, the anode active material includes any alloy of silicon, lithium, and / or combinations thereof. In some embodiments, the anode active material is lithium titanate (Li4Ti5O 12 , also known as "LTO"), tin-cobalt oxide, or a combination thereof.

[0077] In one embodiment, the electroactive lithium-containing material of the second electrode (e.g., anode) comprises greater than 50% lithium by weight. In another embodiment, the electroactive lithium-containing material of the second electrode comprises greater than 75% lithium by weight. In yet another embodiment, the electroactive lithium-containing material of the second electrode comprises greater than 90% lithium by weight. Additional materials and configurations suitable for use in the second electrode are described, for example, in U.S. Patent Publication No. 2010 / 0035128 to Scordilis-Kelley et al., entitled "Application of Forces in Electrochemical Cells," filed Aug. 4, 2009, which is incorporated herein by reference in its entirety for all purposes.

[0078] In some cases, lithium metal / lithium metal alloy may be present for only part of the charge / discharge cycle. For example, a cell may be constructed with no lithium metal / lithium metal alloy present on a current collector (e.g., a second current collector), and then lithium metal / lithium metal alloy may be deposited on the second current collector during a charging step. In some embodiments, lithium may be completely depleted after discharge, such that lithium is present for only part of the charge / discharge cycle.

[0079] A variety of first electrodes (e.g., cathodes) may also be used in the embodiments described herein (e.g., as first electrode 102 in FIG. 1B). In some embodiments, the first electrode (e.g., cathode) comprises a treated nickel-containing intercalation compound. In some embodiments, the electroactive material of the first electrode (e.g., cathode) comprises one or more additional cathode active materials in addition to the treated nickel-containing intercalation compound. Examples of additional 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.

[0080] In some embodiments, the cathode active material comprises one or more metal oxides. In some embodiments, an intercalation electrode (e.g., lithium intercalation electrode, lithium intercalation electrode) may be used. Non-limiting examples of suitable materials that can intercalate the ions (e.g., alkali metal ions) of the electroactive material include metal oxides, titanium sulfide, and iron sulfide. In some embodiments, the first electrode (e.g., cathode) is an intercalation electrode that comprises a lithium transition metal oxide or a lithium transition metal phosphate. Additional examples include Li x CoO2 (e.g., Li 1.1 CoO2), Li x NiO2, Li x MnO2, Li x Mn2O4 (e.g., Li 1.05Mn2O4), Li x CoPO4, Li x MnPO4, LiCo x Ni (1-x) O2, and LiCo x Ni y Mn (1-x-y) O2 (e.g., LiNi 1 / 3 Mn 1 / 3 Co 1 / 3 O2, LiNi 3 / 5 Mn 1 / 5 Co 1 / 5 O2, LiNi 4 / 5 Mn 1 / 10 Co 1 / 10 O2, LiNi 1 / 2 Mn 3 / 10 Co 1 / 5 O2). X can be 0 to 2, inclusive. X is typically 1 to 2, inclusive, when the electrochemical device is fully discharged, and 1 to 2, inclusive, when the electrochemical device is fully charged. In some embodiments, a fully charged electrochemical device can have a value of x that is 1 to 1.05, 1 to 1.1, or 1 to 1.2, inclusive. Further examples include (0 <x≦1)であるLi x NiPO4, (x+y=2) LiMn x NiO y4 (For example, LiMn 1.5 Ni 0.5 O4), (x+y+z=1) LiNi x Co y Al z O2, LiFePO4, where (x+y+z=1), and combinations thereof. In some embodiments, the electroactive material in the first electrode (e.g., cathode) comprises a lithium transition metal phosphate (e.g., LiFePO4), which in some embodiments can be substituted with a borate and / or a silicate.

[0081] A first electrode (e.g., cathode) of the present invention may comprise about 20-100% by weight of electroactive first electrode material (e.g., measured after an appropriate amount of solvent has been removed from the first electrode active layer and / or after the layer has been appropriately cured). In one embodiment, the amount of nickel-containing intercalation compound ranges from 5-30% by weight of the first electrode. In another embodiment, the amount of nickel-containing intercalation compound in the first electrode ranges from 20% to 90% by weight of the first electrode.

[0082] In some embodiments, an electrode (e.g., a second electrode, an anode) of an electrochemical device may include one or more coatings or layers formed from polymers, ceramics, and / or glasses. The coatings act as protective layers and can perform different functions. These functions can include preventing the formation of dendrites during recharge that could otherwise cause short circuits, preventing reactions between the electrode active material and the electrolyte, and improving cycle life. Examples of such protective layers include those described in U.S. Pat. No. 8,338,034 to Affinito et al. and U.S. Patent Publication No. 2015 / 0236322 to Laramie et al., each of which is incorporated herein by reference in its entirety for all purposes.

[0083] In some embodiments, the electrochemical cell includes a separator. The separator generally includes a polymeric material (e.g., a polymeric material that may or may not swell when exposed to an electrolyte). In some embodiments, the separator is located between a first electrode and a second electrode (e.g., an anode and a cathode).

[0084] The pores of the separator may be partially or substantially filled with liquid electrolyte. The separator may be provided as a porous free-standing film that is interleaved with the first electrode and / or second electrode (e.g., anode and cathode) during cell fabrication. Alternatively, a porous separator layer may be applied directly to one surface of the electrodes, as described, for example, in PCT Publication No. WO 99 / 33125 to Carlson et al. and U.S. Patent No. 5,194,341 to Bagley et al.

[0085] A variety of separator materials are known in the art. Examples of suitable solid porous separator materials include, but are not limited to, polyolefins such as polyethylene (e.g., Tonen Chemical's SETELA™) and polypropylene, glass fiber filter paper, 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 devices (including electrochemical cells) described herein include microporous xerogel layers, such as microporous pseudoboehmite layers, as described in U.S. Patent Nos. 6,153,337 and 6,306,545 by Carlson et al., which can be provided either as a free-standing film or by coating application directly on one of the electrodes (e.g., the second electrode). Solid electrolytes and gel electrolytes function as separators in addition to electrolyte functions.

[0086] The separator generally comprises a polymeric material (e.g., a polymeric material that may or may not swell when exposed to an electrolyte). In some embodiments, the separator is disposed 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 a first electrode, or between the electrolyte and a second electrode).

[0087] The separator can be made of a variety of materials. In some embodiments, the separator can be polymeric, and in other embodiments, the separator can be formed of an inorganic material (e.g., fiberglass filter paper). Examples of suitable separator materials include polyolefins (e.g., polyethylene, poly(butene-1), poly(n-pentene-2), polypropylene, polytetrafluoroethylene), polyamines (e.g., poly(ethyleneimine) and polypropyleneimine (PPI)); polyamides (e.g., polyamide (nylon), poly(ε-caprolactam) (nylon 6), poly(hexamethylene adipamide) (nylon 66)), polyimides (e.g., polyimide, polynitrile, poly(pyromellitimide-1), poly(pyromellitimide-2), ... , 4-diphenyl ether) (Kapton®), (NOMEX®), (KEVLAR®), etc.; polyether ether ketone (PEEK); vinyl polymers (e.g., polyacrylamide, poly(2-vinylpyridine), poly(N-vinylpyrrolidone), poly(methyl cyanoacrylate), poly(ethyl cyanoacrylate), poly(butyl cyanoacrylate), poly(isobutyl cyanoacrylate), poly(vinyl acetate), poly(vinyl alcohol), poly(vinyl chloride), etc.) poly(vinyl fluoride), poly(2-vinylpyridine), vinyl polymers, polychlorotrifluoroethylene, and poly(isohexyl cyanoacrylate); polyacetals; polyesters (e.g., polycarbonate, polybutylene terephthalate, polyhydroxybutyrate); polyethers (poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO), poly(tetramethylene oxide) (PTMO)); vinylidene polymers (e.g., polyisobutylene, poly(methylene poly(vinylidene fluoride), poly(methyl methacrylate) (PMMA), poly(vinylidene chloride) and poly(vinylidene fluoride); polyaramids (e.g., poly(imino-1,3-phenyleneiminoisophthaloyl) and poly(imino-1,4-phenyleneiminoterephthaloyl)); polyheteroaromatics (e.g., polybenzimidazole (PBI), polybenzobisoxazole (PBO) and polybenzobisthiazole (PBT)); polyheterocyclics (e.g., polypyrrole); polyurethanes;These include, but are not limited to, phenolic polymers (e.g., phenol-formaldehyde); polyalkynes (e.g., polyacetylene); 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., polyphosphazenes, polyphosphonates, polysilanes, polysilazanes). In some embodiments, the polymer may be selected from poly(n-pentene-2), polypropylene, polytetrafluoroethylene, polyamides (e.g., polyamide (nylon), poly(ε-caprolactam) (nylon 6), poly(hexamethylene adipamide) (nylon 66)), polyimides (e.g., polynitrile, poly(pyromellitimide-1,4-diphenyl ether) (Kapton®) (NOMEX®) (KEVLAR®)), polyether ether ketone (PEEK), and combinations thereof;

[0088] In some embodiments, the electrochemical cell includes a protective layer over the electroactive material of the electrode (e.g., first electrode, second electrode). In general, a "protective layer" is a layer of material that protects the electrode active material in the electrode from non-electrochemical chemical reactions or other undesirable interactions with species in the electrochemical cell. For example, the protective layer can be configured to prevent chemical reactions or other undesirable interactions between the electrode active material and species in the electrolyte, and / or between the electrode active material and by-products of the electrochemical reactions in the electrochemical cell. According to some embodiments, the protective layer overlies the electroactive material of the second electrode (e.g., anode). For example, according to some embodiments, the protective layer is disposed between the second electrode (e.g., anode) and a separator.

[0089] In some embodiments, the electrochemical cells described herein include a first current collector (e.g., first current collector 110 of FIGS. 1A-1B). The first current collector may be electronically coupled to a first electrode and / or a plurality of first electrode portions of the electrochemical cell.

[0090] The electrochemical cells described herein may include one or more current collectors, as described above. In some cases, the electrochemical cells include a second current collector (e.g., optional second current collector 112 of FIGS. 1A-1B). The second current collector may be electronically coupled to a second electrode and / or a plurality of second electrode portions of the electrochemical cell.

[0091] In some embodiments, it may be advantageous to apply an anisotropic force to the electrochemical cell described herein during charging and / or discharging. The electrochemical cell may include an electrolyte comprising an asymmetric sulfonamide described herein. In some embodiments, the electrochemical cell and / or electrode described herein may be adapted to withstand an applied anisotropic force (e.g., a force applied to reinforce the morphology of the electrode in the cell) while maintaining its structural integrity. The electrodes described herein may be part of an electrochemical cell adapted and arranged such that an anisotropic force having a component perpendicular to the active surface of the electrode (e.g., an anode comprising lithium metal and / or lithium alloy) in the electrochemical cell is applied to the cell during at least one period during charging and / or discharging of the cell. In one set of embodiments, the applied anisotropic force may be selected to reinforce the morphology of the electrode (e.g., an anode such as a lithium metal and / or lithium alloy anode). As understood in the art, an "anisotropic force" is a force that is not equal in all directions.

[0092] In such cases, the anisotropic force includes a component perpendicular to the active surface of the electrodes (e.g., the first electrode, such as the cathode, the second electrode, such as the anode) in the electrochemical cell. In this specification, the term "active surface" is used to refer to the surface of the electrode where an electrochemical reaction can occur. A force having a "normal component" relative to the surface is given its ordinary meaning as understood by those skilled in the art, and includes, for example, a force that exerts itself at least partially in a direction substantially perpendicular to the surface. For example, if an object rests on a horizontal table and is only influenced by gravity, the object exerts a force in a direction substantially completely perpendicular to the surface of the table. If the object is also biased laterally across the surface of the horizontal table, the object exerts a force on the table that is not completely perpendicular to the horizontal surface, but includes a component perpendicular to the surface of the table. Those skilled in the art will understand other examples of these terms, especially those that apply in the description herein. In the case of a curved surface (e.g., concave or convex), the component of the anisotropic force perpendicular to the active surface of the electrode may correspond to a component perpendicular to a plane tangent to the curved surface at the point where the anisotropic force is applied. The anisotropic force may be applied at one or more predetermined locations, optionally distributed randomly on the active surface of the anode. In some embodiments, the anisotropic force is applied uniformly across the active surfaces of the first electrode (e.g., cathode) and / or the second electrode (e.g., anode).

[0093] Any of the electrochemical cell properties and / or performance metrics described herein may be achieved, alone or in combination with one another, during the application of an anisotropic force to the electrochemical cell during charging and / or discharging (e.g., during charging and / or discharging of the cell). In some embodiments, the anisotropic force applied to an electrode, to an electrochemical cell (e.g., during at least one period during charging and / or discharging of the cell) may include a component perpendicular to an active surface of the electrode (e.g., an anode, such as a lithium metal and / or lithium alloy anode in an electrochemical cell). In some embodiments, the component of the anisotropic force perpendicular to the active surface of the electrode is greater than or equal to 1 kg / cm. 2 More than 2kg / cm 2 Above 4kg / cm2 More than 6kg / cm 2 More than 8kg / cm 2 More than 10kg / cm 2 More than 12kg / cm 2 More than 14kg / cm 2 Above,16kg / cm 2 Above,18kg / cm 2 Above,20kg / cm 2 Above, 22kg / cm 2 Above,24kg / cm 2 Over,26kg / cm 2 Above,28kg / cm 2 Above,30kg / cm 2 Above,32kg / cm 2 Above,34kg / cm 2 Above, 36kg / cm or above, 38kg / cm 2 More than 40kg / cm 2 More than 42kg / cm 2 More than 44kg / cm 2 Above, 46kg / cm 2 or more, or 48kg / cm 2 In some embodiments, the component of the anisotropic force perpendicular to the active surface is greater than or equal to, for example, 50 kg / cm 2 Below, 48kg / cm 2 Below, 46kg / cm 2 Below, 44kg / cm 2 Below, 42kg / cm 2 Below, 40kg / cm 2 Below, 38kg / cm 2 Below, 36kg / cm 2 Below, 34kg / cm 2 Below, 32kg / cm 2 Below 30kg / cm 2 Below,28kg / cm 2 Below,26kg / cm 2 Below,24kg / cm 2 Below,22kg / cm 2 Below,20kg / cm or less 2 ,18kg / cm 2 Below, 16kg / cm 2 Below, 14kg / cm 2 Below, 12kg / cm2 Below, 10kg / cm 2 Below, 8kg / cm 2 Below 6kg / cm 2 Below, 4kg / cm 2 or less than 2kg / cm 2 The following pressures can be specified. Combinations of the above ranges are also possible (e.g. 1 kg / cm 2 More than 50kg / cm 2 (See below). Other ranges are possible.

[0094] The anisotropic forces applied during charging and / or discharging as described herein may be applied using any method known in the art. In some embodiments, the forces may be applied using compression springs. The forces may be applied using other elements (either internal or external to the containment structure), including, but not limited to, Belleville washers, machine screws, pneumatic devices, and / or weights, among others. In some cases, the cells are pre-compressed before being inserted into the containment structure, and expand upon insertion into the containment structure to generate a net force on the cells. Suitable methods for applying such forces are described in detail, for example, in U.S. Pat. No. 9,105,938, which is incorporated herein by reference in its entirety.

[0095] The term "aliphatic" as used herein includes both saturated and unsaturated, non-aromatic, straight-chain (i.e., unbranched), branched, acyclic, and cyclic (i.e., carbocyclic) hydrocarbons, which are optionally substituted with one or more functional groups. As will be appreciated by those skilled in the art, "aliphatic" is intended herein to include, but is not limited to, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, and cycloalkynyl moieties. Similarly, the term "heteroaliphatic" refers to heteroalkyl, heteroalkenyl, heteroalkynyl, and heterocyclic groups. Thus, the term "alkyl" as used herein includes straight-chain, branched, and cyclic alkyl groups. A similar convention applies to other general terms, such as "alkenyl," "alkynyl," and the like. Additionally, 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 refer to an aliphatic group (cyclic, acyclic, substituted, unsubstituted, branched or unbranched) having 1-20 carbon atoms. Substituents of aliphatic groups 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, heteroaliphatic, heterocyclic, aryl, heteroaryl, acyl, oxo, imino, thioxo, cyano, isocyano, amino, azido, nitro, hydroxyl, thiol, halo, aliphatic amino, heteroaliphatic amino, alkylamino, heteroalkylamino, arylamino, heteroarylamino, alkylaryl, arylalkyl, aliphaticoxy, heteroaliphaticoxy, alkyloxy, heteroalkyloxy, aryloxy, heteroaryloxy, aliphaticthioxy, heteroaliphaticthioxy, alkylthioxy, heteroalkylthioxy, arylthioxy, heteroarylthioxy, acyloxy, etc., each of which may be further substituted or unsubstituted).

[0096] 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. Alkyl groups may be optionally substituted, as described in more detail 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. A "heteroalkyl" group is an alkyl group in which at least one atom is a heteroatom (e.g., oxygen, sulfur, nitrogen, phosphorus, and the like) and the remaining atoms are carbon atoms. Examples of heteroalkyl groups include, but are not limited to, alkoxy, poly(ethylene glycol)-, alkyl substituted amino, tetrahydrofuranyl, piperidinyl, morpholinyl, and the like.

[0097] The terms "alkenyl" and "alkynyl" refer to unsaturated aliphatic groups analogous to the alkyl groups described above, but which contain at least one double or triple bond respectively. "Heteroalkenyl" and "heteroalkynyl" refer to alkenyl and alkynyl groups, as described herein, in which one or more atoms is a heteroatom (e.g., oxygen, nitrogen, sulfur, etc.).

[0098] The term "haloaliphatic" refers to an aliphatic group in which one or more hydrogen atoms, for example, 1 to 10 hydrogen atoms, are independently replaced with a halogen atom, such as fluoro, bromo, chloro, iodo, and the like.

[0099] The term "haloheteroaliphatic" refers to a heteroaliphatic group in which one or more hydrogen atoms, such as 1 to 10 hydrogen atoms, are independently replaced with a halogen atom, such as fluoro, bromo, chloro, or iodo.

[0100] The term "haloalkyl" refers to a substituted alkyl group in which one or more of the hydrogen atoms are independently replaced with a halogen, such as fluoro, bromo, chloro, or iodo. In some embodiments, the haloalkyl moiety has 1 to 8 carbon atoms ("C 1-8 In some embodiments, the haloalkyl moiety is a moiety having 1 to 6 carbon atoms ("C 1-6 In some embodiments, the haloalkyl moiety has 1 to 4 carbon atoms ("C 1-4 In some embodiments, the haloalkyl moiety has 1 to 3 carbon atoms ("C 1-3 In some embodiments, the haloalkyl moiety has 1 to 2 carbon atoms ("C 1-2 Examples of haloalkyl groups include, -CHF2, -CH2F, -CF3, -CH2CF3, -CF2CF3, -CF2CF2CF3, -CCl3, -CFCl2, -CF2Cl, and the like.

[0101] The term "aryl" refers to an aromatic carbocyclic group having a single ring (e.g., phenyl), multiple rings (e.g., biphenyl), or multiple condensed rings, at least one of which is aromatic (e.g., 1,2,3,4-tetrahydronaphthyl, naphthyl, anthryl, or phenanthryl), all of which are optionally substituted. A "heteroaryl" group is an aryl group in which at least one ring atom in the aromatic ring is a heteroatom and the remaining ring atoms are carbon atoms. Examples of heteroaryl groups include furanyl, thienyl, pyridyl, pyrrolyl, N-lower alkyl pyrrolyl, pyridyl N-oxide, pyrimidyl, pyrazinyl, imidazolyl, indolyl, and the like, all of which are optionally substituted.

[0102] The terms "amine" and "amino" refer to both unsubstituted and substituted amines, such as those of the general formula: N(R')(R'')(R'') [wherein R', R'' and R''' each independently represent a group permitted by the valence rules.]

[0103] The terms "acyl group," "carboxyl group," or "carbonyl group" are art-recognized and can be understood to have the general formula: [ka] wherein W is H, OH, O-alkyl, O-alkenyl, or a salt thereof. When W is O-alkyl, the formula represents an "ester." The moiety may include a moiety represented by the formula: When W is OH, the formula represents a "carboxylic acid." In general, when the oxygen atom in the above formula is replaced with sulfur, the formula represents a "thiolcarbonyl" group. When W is S-alkyl, the formula represents a "thiol carboxylic acid." On the other hand, when W is alkyl, the formula represents a "ketone" group. When W is hydrogen, the formula represents an "aldehyde" group.

[0104] As used herein, the term "heteroaromatic" or "heteroaryl" refers to a monocyclic or polycyclic heteroaromatic ring (or radical thereof) containing carbon atom ring members and one or more heteroatom ring members (e.g., oxygen, sulfur, or nitrogen, etc.). Typically, the heteroaromatic ring has 5 to about 14 ring members, with at least one ring member being a heteroatom selected from oxygen, sulfur, and nitrogen. In another embodiment, the heteroaromatic ring may be a 5- or 6-membered ring and contain 1 to about 4 heteroatoms. In another embodiment, the heteroaromatic ring system may have 7 to 14 ring members and contain 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, knizaolinyl, 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.

[0105] The term "substituted" is intended to include all permissible substituents of organic compounds, with "permissible" being in the context of chemical rules of valency known to those skilled in the art. In some cases, "substituted" may generally refer to the replacement of hydrogen with a substituent as described herein. However, as used herein, "substituted" does not encompass the replacement and / or change of the primary functional group by which the molecule is identified, such as, for example, the "substituted" functional group becoming a different functional group through substitution. For example, a "substituted phenyl" must still include a phenyl moiety, and cannot, by this definition, be modified by substitution to become, for example, a heteroaryl group such as pyridine. In a broad aspect, permissible substituents include acyclic and cyclic, branched and unbranched, carbocyclic and heterocyclic, aromatic and nonaromatic substituents of organic compounds. Exemplary substituents include, for example, those described herein. Permissible substituents can be one or more and can be the same or different for appropriate organic compounds. For purposes of this invention, heteroatoms such as nitrogen may have hydrogen substituents and / or any permissible substituents of organic compounds described herein which satisfy the valences of the heteroatoms. This invention is not intended to be limited in any manner by the permissible substituents of organic compounds.

[0106] 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, carboxyester, carboxyl, carboxamido, nitro, acyloxy, aminoalkyl, alkylaminoaryl, alkylaryl, alkylaminoalkyl, alkoxyaryl, arylamino, aralkylamino, alkylsulfonyl, carboxamidoalkylaryl, carboxamidoaryl, hydroxyalkyl, haloalkyl, alkylaminoalkylcarboxy, aminocarboxamidoalkyl, alkoxyalkyl, perhaloalkyl, arylalkyloxyalkyl, and the like.

[0107] When a part (e.g., a layer, structure, region) is referred to as "on," "adjacent," "above," "over," or "supported by" another part, it should be understood that there can be intervening parts (e.g., layers, structures, regions) directly present in the part. Similarly, when a part is "below" or "underneath" another part, the part can be directly below the part, or there can be intervening parts (e.g., layers, structures, regions) as well. A part is "directly," "directly adjacent," "immediately adjacent," "in direct contact with," or "directly supported by" another part means that there are no intervening parts. It should also be understood that when a part is referred to as being "on," "above," "adjacent," "over," "overlaying," "abutting," "under" or "supported by" another part, it may cover the entire part or only a portion of the part.

[0108] The following examples are intended to illustrate some embodiments of the present invention, but do not exemplify the full scope of the invention. EXAMPLES

[0109] Example 1 This example describes the synthesis of the unsymmetrical sulfonamide N-ethyl-N-trimethylsilyl trifluoromethylsulfonamide (Et(Me3Si)NSO2CF3). Under an inert atmosphere, anhydrous triflic (130.4 g, 77.74 mL, 0.462 mol) was added dropwise to a 2 M solution of ethylamine in tetrahydrofuran (50 g, 554.51 mL, 1.109 mol) cooled to -70 °C. The reaction mixture was allowed to warm to room temperature and stirred for 12 h. The solvent was evaporated, 500 mL H2O was added to the residue, and the resulting mixture was extracted with CHCl2. The extract was dried over CaCl2 for several hours. The solvent was distilled at atmospheric pressure. Vacuum distillation (bp 81 °C / 15 mmHg) gave 36.82 g (45% yield) of N-ethyl trifluoromethylsulfonamide. 1 HNMR in CDCl3: 1.26 ppm, 3H(t 3 J=7.2Hz), 3.35ppm, 2H(q 3 J=7.2Hz), 5.31ppm, 1 H(s), 13 CNMRinCDCl3:15.7ppm(CH3),39.92ppm(CH2),119.9ppm(CF3)(q 1 JC-F=320.8Hz), 19 FNMR in CDCl3: -77.97 ppm(s).

[0110] At room temperature under argon atmosphere, N-ethyltrifluoromethylsulfonamide (18.46 g, 0.104 mol) was dissolved in 150 mL of tetrahydrofuran, and KH (4.179 g, 0.104 mol) was added in portions while stirring, and stirring was continued for 12 h. To the potassium salt formed, Me3SiCl (11.32 g, 13.22 mL, 0.104 mol) was added, and the reaction mixture was stirred at room temperature for 12 h. The resulting reaction mixture was filtered to remove the precipitate. The solvent was distilled at atmospheric pressure. Vacuum distillation (bp 57 °C / 15 mmHg) gave 14.258 g (55% yield) of the desired product. 1 HNMRinCDCl3:0.40ppm,9H(sSiMe3),1.28ppm,3H(t 3 J=7.1Hz), 3.36ppm, 2H(q 3 J=7.1Hz), 13 CNMRinCDCl3:0.97ppm(SiMe3),17.41ppm(CH3),43.39ppm(CH2),120.08ppm(CF3)(q 1 JC-F=323.18Hz), 19 FNMR in CDCl3: -76.68 ppm(s), 29 SiNMR in CDCl3: 21.12 ppm(s).

[0111] Example 2 This example describes the synthesis of pyrrolyl perfluorobutylsulfonamide, an unsymmetrical sulfonamide containing an N-linked heterocycle. This compound was synthesized by the following protocol. Perfluorobutylsulfonyl fluoride (12.4 g, 0.04 mol) was added in portions to a stirred suspension of lithium pyrophosphate (prepared from pyrrole and MeLi) (3 g, 0.04 mol) in 150 mL of diethyl ether under inert atmosphere to form a reaction mixture. The reaction mixture was stirred at room temperature for 12 hours. The reaction mixture was poured into 500 mL of water and the resulting aqueous layer was extracted with diethyl ether (2x75 mL) and methylene chloride (75 mL). The combined extracts were dried over anhydrous sodium sulfate. The solvent was removed at atmospheric pressure. The resulting residue was distilled in vacuum (bp 22 oC / 0.7mmHg), yield 54.2% (7.78g). 1 HNMRinCDCl3:6.47ppm,2Hm,7.14ppm2Hm, 13 CNMRinCDCl3:115.66ppm(2CH),122.67ppm(2CH),107-123ppm(m,C4F9), 19 FNMRinCDCl3:-126.12ppm(m,CF2),-121.20ppm(m,CF2),-111.04ppm(m,CF2),-80.98ppm(tt,CF3, 3 J F-F =9.8Hz, 4 J F-F =2.3Hz).

[0112] Example 3 This example describes the synthesis of imidazolyl perfluorobutylsulfonamide, an unsymmetrical sulfonamide containing an N-linked heterocycle. This compound was synthesized by the following protocol. Perfluorobutylsulfonyl fluoride (12.4 g, 0.04 mol) was added in portions to a stirred suspension of Li imidazolate (prepared from imidazole and MeLi) (3 g, 0.04 mol) in 150 mL of diethyl ether under inert atmosphere to form a reaction mixture. The reaction mixture was stirred at room temperature for 12 h. The reaction mixture was poured into 500 mL of water and the resulting aqueous layer was extracted with diethyl ether (2x75 mL) and methylene chloride (75 mL). The combined extracts were dried over anhydrous sodium sulfate. The solvent was removed at atmospheric pressure. The resulting residue was distilled in vacuum (bp 22 o C / 0.7mmHg) and a yield of 56.1% was obtained. 1 HNMRinCDCl3:7.28ppm,1Hdd(3J=1.8Hz,4J=0.8Hz),7.39ppm1Hm,8.04ppm1Hm, 13 CNMRinCDCl3:119.35ppm(1CH),132.74ppm(1CH),138.41ppm(1CH),105-120ppm(m,C4F9), 19FNMRinCDCl3:-126.29ppm(m,CF2),-121.09ppm(m,CF2),-110.41ppm(m,CF2),-81.21ppm(tt,CF3, 3 J F-F =9.7Hz, 4 J F-F =2.1Hz).

[0113] Example 4 In this embodiment, NCM811 (LiNi 0.8 Co 0.1 Mn 0.1 The authors compare the performance of exemplary electrolytes including asymmetric sulfonamides, linear carbonates, and cyclic carbonates in a cell containing a 1000-millimeter thick O2 cathode, a 50-micrometer thick lithium anode, and a 9-micrometer thick polyolefin separator. The effective electrode area of ​​the cell is 99.4 cm. 2 The electrolyte was 0.5 mL. The composition of each electrolyte is shown in Table 1. The asymmetric sulfonamides used were N,N-dimethylfluorosulfonamide (Me2NSO2F), N,N-diethyltrifluoromethylsulfonamide (Et2NSO2CF3), N,N-dimethyltrifluoromethylsulfonamide (Me2NSO2CF3), and N-ethyl-N-trimethylsilyltrifluoromethylsulfonamide (Et(Me3Si)NSO2CF3). Unlike electrolytes 1-3, electrolytes 4-5 contain lithium bis(fluorosulfonyl)imide (LiFSI) instead of lithium hexafluorophosphate (LiPF6). In addition, electrolyte 4 contains ethylmethylcarbonate instead of dimethylcarbonate as the linear carbonate. For reference, a carbonate electrolyte without asymmetric sulfonamide was also analyzed (electrolyte 6). During the electrical tests, the cells were loaded with 12 kg / cm 2A pressure of 10 ...

[0114] [Table 1]

[0115] Example 5 In this embodiment, NCM811 (LiNi 0.8 Co 0.1 Mn 0.1 The overcharge stability of exemplary electrolytes including asymmetric sulfonamides, linear carbonates, and cyclic carbonates is compared in a cell containing a 0.1% CrO2 cathode, a 50 micrometer thick lithium anode, and a 9 micrometer thick polyolefin separator. The effective electrode area of ​​the cell is 1280 cm. 2 The electrolyte was 7 mL. The composition of each electrolyte is shown in Table 2. The unsymmetrical sulfonamides used were N,N-dimethylfluorosulfonamide (Me2NSO2F), N,N-diethyltrifluoromethylsulfonamide (Et2NSO2CF3), and N,N-dimethyltrifluoromethylsulfonamide (Me2NSO2CF3). For reference, a carbonate electrolyte without unsymmetrical sulfonamide was also analyzed (electrolyte 6). During electrical testing, the cells were loaded with 12 kg / cm 2The cells were charged at 4.35 V with a charge current of 0.5 A and discharged at 3.2 V with a discharge current of 2 A. Initially, the cells had a charge storage capacity of 6 Ah. The cells were subjected to four charge-discharge cycles and charged to 100% state of charge (SOC) before the overcharge test. The overcharge test was performed for 60 minutes with a charge current of 18 A. The cell voltage and temperature were monitored during the test. Three cells were tested for each electrolyte. Table 2 shows the average test data. The results indicate that the electrolytes containing asymmetric sulfonamides have a favorable relationship between higher maximum voltage during overcharge (i.e., overcharge voltage) and lower temperature.

[0116] [Table 2]

[0117] Example 6 In this embodiment, NCM811 (LiNi 0.8 Co 0.1 Mn 0.1 The thermal stability of exemplary electrolytes containing asymmetric sulfonamides, linear carbonates, and cyclic carbonates was compared in a cell containing a 02) cathode, a 50 micrometer thick lithium anode, and a 9 micrometer thick polyolefin separator. The cell was identical to the cell used in Example 5. During electrical testing, the cell was loaded with 12 kg / cm 2 A pressure of 0.5 A was applied to the battery. Charging was performed at 4.35 V with a charge current of 0.5 A and discharging was performed at 3.2 V with a discharge current of 2 A. Initially, the cell had a charge storage capacity of 6 Ah. The cell was subjected to four charge-discharge cycles and charged to 100% state of charge (SOC) before thermal stability testing. Thermal stability testing was performed by increasing the temperature from 20° C. at a rate of 5° C. / min until the cell underwent thermal runaway. The temperatures at which thermal runaway occurred are shown in Table 3. These results indicate that the presence of unsymmetrical sulfonamides is favorably associated with an increase in the thermal runaway temperature of at least 10° C.

[0118] [Table 3]

[0119] Example 7 In this example, exemplary cells for gas generation are compared. The cells were identical to those used in Example 5 (only the reference Electrolyte 6 and Electrolyte 8 cells were prepared in this experiment). During electrical testing, the cells were rated at 12 kg / cm 2 The cells were subjected to a pressure of 0.5 A at 4.35 V and 2 A at 3.2 V. Initially, the cell had a charge storage capacity of 6 Ah. The cells were subjected to four charge-discharge cycles and charged to 100% state of charge (SOC) before the gassing test. The gassing test was performed in three stages: 1. Cell volume V1 was measured at 20°C before exposure to high temperature; 2. The cells were stored at 72°C for 60 hours; 3. The cell was cooled to 20°C and the new cell volume V2 was measured.

[0120] The increase in cell volume (V2-V1) is mainly due to gas evolution during high temperature storage. During testing, the cell with reference electrolyte 6 showed a volume increase of 33.32 mL, while the cell with electrolyte 8 showed a volume increase of 28.53 mL. This indicates that the cell with electrolyte 8 showed less gas evolution, indicating that unsymmetrical sulfonamides may favorably suppress gas evolution in electrochemical cells.

[0121] Example 8 In this embodiment, NCM811 (LiNi 0.8 Co 0.1 Mn 0.1 The performance of an exemplary electrolyte containing an asymmetric sulfonamide and a cyclic carbonate was compared to the cyclic carbonate alone in a cell containing a 0.1% CrO2 cathode, a 50 micrometer thick lithium anode, and a 9 micrometer thick polyolefin separator. The effective electrode area of ​​the cell was 99.4 cm. 2The electrolyte was 0.5 mL. The composition of each electrolyte is shown in Table 4. The unsymmetrical sulfonamide was N,N-diethyltrifluoromethylsulfonamide (Et2NSO2CF3). During electrical testing, the cells were loaded with 12 kg / cm 2 The cells were charged at 4.4 V with a charge current of 75 mA and discharged at 3.0 V with a discharge current of 300 mA. Initially, the cells had a charge storage capacity of 123 mAh. The cells were cycled until they reached a charge storage cutoff capacity of 70 mAh, and the cycle life (the number of charges until the charge storage cutoff capacity was reached) was determined at this point. Three cells per electrolyte were tested. The results show that the cycle life of the cells containing the asymmetric sulfonamide was longer than that of the cells containing the reference electrolyte. These results show that the asymmetric sulfonamide and fluoroethylene carbonate can produce cells with high cycle life in some embodiments. For example, compared to reference electrolyte 6 in Example 4, electrolytes 10 and 11 had better cycle life. Unexpectedly, however, the cycle lives of cells comprising a combination of an asymmetric sulfonamide, a linear carbonate, and a cyclic carbonate exceeded those of cells containing electrolytes lacking one of these components, and the lowest cycle life of such combinations, electrolyte 2 (cycle life: 1039 cycles), exceeded the cycle life of the electrolytes reported in this disclosure by more than a factor of two.

[0122] [Table 4]

[0123] Example 9 In this embodiment, NCM811 (LiNi 0.8 Co 0.1 Mn 0.1The performance of an exemplary electrolyte containing an asymmetric sulfonamide and a cyclic carbonate is compared to a linear carbonate alone in a cell containing a 02 (O2) cathode, a 50 micrometer thick lithium anode, and a 9 micrometer thick polyolefin separator. Additionally, the example compares the performance of an electrolyte containing the symmetric sulfonamide, N,N,N',N'-tetraethylsulfamide (Et2NSO2NEt2), to that containing the asymmetric sulfonamide. The cell has an active electrode area of ​​99.4 cm2. 2 The electrolyte was 0.5 mL. The composition of each electrolyte is shown in Table 4. The unsymmetrical sulfonamides used were N,N-diisopropyltrifluoromethylsulfonamide (iPr2NSO2CF3), N,N-diethyltrifluoromethylsulfonamide (Et2NSO2CF3), N,N-dimethyltrifluoromethylsulfonamide (Me2NSO2CF3), and N,N-ethylmethyltrifluoromethylsulfonamide (EtMeNSO2CF3). During electrical testing, the cells were loaded with 12 kg / cm 2 A pressure of 1000 mA was applied. Charging was performed at 4.4 V with a charge current of 75 mA, and discharging was performed at 3.0 V with a discharge current of 300 mA. Initially, the cell had a charge storage capacity of 123 mAh. The cells were cycled until they reached a charge storage cutoff capacity of 70 mAh, and the cycle life (number of charges until the charge storage cutoff capacity was reached) was determined at this point. Three cells per electrolyte were tested. Unexpectedly, the cycle life of cells containing combinations of asymmetric sulfonamides, linear carbonates, and cyclic carbonates exceeded the cycle life of cells containing electrolytes lacking any of these components, and the shortest cycle life of such combinations, electrolyte 2 (cycle life: 1039 cycles), exceeded the cycle life of the electrolytes reported here by more than four times.

[0124] [Table 5]

[0125] Although several embodiments of the invention have been described and illustrated herein, those skilled in the art can readily envision various other means and / or structures for performing the functions and / or results and / or obtaining one or more advantages described herein, and each such variation and / or modification 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 on the particular use or application for which the teachings of the present invention are / are used. Those skilled in the art will recognize, or be able to ascertain with no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Thus, the foregoing embodiments are presented by way of example only, and it will be understood that within the scope of the appended claims and their equivalents, 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. Furthermore, any combination of two or more such features, systems, articles, materials, and / or methods is within the scope of the present invention, provided that such features, systems, articles, materials, and / or methods are not mutually inconsistent.

[0126] The indefinite articles "a" and "an," as used in the specification and claims, unless clearly indicated to the contrary, should be understood to mean "at least one."

[0127] The term "and / or" as used herein and in the claims should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are conjunctive in some cases and disjunctive in other cases. Other elements may be optionally present other than the elements specifically identified by the "and / or" clause, whether related or unrelated to the specifically identified elements, unless expressly indicated to the contrary. Thus, as a non-limiting example, a reference to "A and / or B," when used in combination with open-ended language such as "comprising," can refer to, in one embodiment, A without B (optionally including elements other than B); in another embodiment, B without A (optionally including elements other than A); in yet another embodiment, both A and B (optionally including other elements); and so forth.

[0128] As used herein 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., including at least one, but not more than one, of a number or list of elements, and optionally further including items not in the list. Only terms clearly indicating the contrary, such as "only one of," "exactly one of," or, when used in the claims, "consisting of," refer to the inclusion of exactly one element of a number or list of elements. In general, the term "or" as used herein shall be interpreted as indicating exclusive alternatives (i.e., "one or the other, but not both") only when preceded by an exclusive term, such as "either," "one of," "only one of," or "exactly one of." "Consisting essentially of," as used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0129] As used herein and in the claims, the phrase "at least one" referring to a list of one or more elements should be understood to mean at least one element selected from any one or more elements in the list of elements, but not necessarily including at least one of each and every element specifically listed in the list of elements, and not excluding any combination of elements in the list of elements. This definition also allows that elements other than those specifically identified in the list of elements to which the phrase "at least one" refers may optionally be present, whether or not related to the specifically identified elements. 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 one or more, A, where B is absent (and optionally including elements other than B); in another embodiment, to at least one, optionally one or more, B, where A is absent (and optionally including elements other than A); in yet another embodiment, to at least one, optionally one or more, A, and at least one, optionally one or more, B (and optionally including other elements); etc.

[0130] As used herein, "wt%" is an abbreviation for weight percent. As used herein, "at%" is an abbreviation for atomic percent. In the claims, the use of ordinal terms such as "first," "second," "third," etc. to modify claim elements does not, in and of itself, imply a priority, precedence, or order of one claim element relative to other claim elements, or the chronological order in which acts of a method are performed, but is merely used as a label to distinguish one claim element having a certain name from another element having the same name (but using an ordinal term) to distinguish between claim elements.

[0131] As in the specification above, in the claims, all transitional words such as "comprising," "including," "carrying," "having," "involving," "holding," and the like are understood to be open-ended, i.e., meaning including but not limited to. As provided for in the United States Patent Office Manual of Patent Examining Procedure, Section 211.03, only the transitional phrases "consisting of" and "consisting essentially of" must be closed or semi-closed transitional phrases, respectively.

Claims

1. a first electrode comprising lithium; a first solvent comprising an asymmetric sulfonamide; and a second solvent; the second solvent includes both cyclic and linear carbonates; The unsymmetrical sulfonamide has the formula (I): 【Chemistry 1】 [In the formula, R １ and R ２ may be the same or different and each independently represents an unsubstituted, branched or unbranched aliphatic chain; a silyl substituent; or R １ and R ２ are selected from those which link to form an N-linked heterocycle; R １ is selected from unsubstituted, branched or unbranched aliphatic chains, R １ contains n carbon atoms, n being an integer between 1 and 10, R ２ is selected from unsubstituted, branched or unbranched aliphatic chains, R ２ contains m carbon atoms, m being an integer between 1 and 10, R １ and R ２ are linked to form an N-linked heterocycle, the N-linked heterocycle contains j carbon atoms, where j is an integer from 2 to 11; R １ and / or R ２ is a silyl substituent, said silyl substituent is SiR ４ ３ and R ４ is an unsubstituted, branched or unbranched aliphatic chain containing k carbon atoms, k being an integer between 1 and 10, inclusive; and R ３ is an electron-withdrawing species.

2. an electrode comprising lithium, and containing asymmetric sulfonamides, The unsymmetrical sulfonamide has the formula (I): 【Chemistry 2】 [In the formula, R １ and R ２ may be the same or different and each represents an unsubstituted, branched or unbranched aliphatic chain; a silyl substituent; or R １ and R ２ are selected from those which link to form an N-linked heterocycle; R １ is selected from unsubstituted, branched or unbranched aliphatic chains, R １ contains n carbon atoms, n being an integer between 1 and 10, and R ２ is a silyl substituent, R ２ is selected from unsubstituted, branched or unbranched aliphatic chains, R ２ contains m carbon atoms, m being an integer between 1 and 10, and R １ is a silyl substituent, R １ and R ２ are linked to form an N-linked heterocycle, the N-linked heterocycle contains j carbon atoms, where j is an integer from 2 to 11, R １ and / or R ２ is a silyl substituent, said silyl substituent is SiR ４ ３ and R ４ is an unsubstituted, branched or unbranched aliphatic chain containing k carbon atoms, k being an integer between 1 and 10, inclusive; and R ３ is an electron-withdrawing species.

3. The electron withdrawing species may be a halogen atom, a substituted or unsubstituted, branched or unbranched haloaliphatic, -CN, -COOR １ , -C(=O)R １ , -CON(R １ ) ２ , -CONR １ H, -NO ２ , -SO ３ R １ , -SO(OR １ ) ２ , -SO(OR １ ) H, -SOR １ , -SO ２ R １ , -PO(OR １ ) ２ , -PO(OR １ ) H, a protonated amine group (e.g., —NR ３ ＋ and -NH ３ ＋ 3. The electrochemical cell of claim 1 or 2, wherein:

4. The substituted aromatic group may be a halogen atom, a substituted or unsubstituted, branched or unbranched haloaliphatic group, -CN, -COOR １ , -C(=O)R １ , -CON(R １ ) ２ , -CONR １ H, -NO ２ , -SO ３ R １ , -SO(OR １ ) ２ , -SO(OR １ ) H, -SOR １ , -SO ２ R １ , -PO(OR １ ) ２ , -PO(OR １ ) H, and / or protonated amine groups (e.g., —NR ３ ＋ and -NH ３ ＋ 4. The electrochemical cell of claim 3 comprising:

5. R １ and R ２ 3. The electrochemical cell of claim 1 or 2, wherein both of said alkyl groups are unbranched aliphatic chains.

6. When R 1 is selected from an unsubstituted, branched or unbranched aliphatic chain, n is 4 or less; When R 2 is selected from an unsubstituted, branched or unbranched aliphatic chain, m is 4 or less; When R 1 and R 2 join to form an N-linked heterocycle, j is 7 or less; and / or 3. An electrochemical cell according to claim 1 or 2, wherein when R 1 and / or R 2 are silyl substituents, k is 4 or less.

7. 3. The electrochemical cell of claim 1 or 2, wherein k is 4 or less.

8. R １ 3. The electrochemical cell of claim 1 or 2, wherein is a silyl substituent.

9. R ２ 3. The electrochemical cell of claim 1 or 2, wherein is a silyl substituent.

10. R １ and R ２ 3. The electrochemical cell of claim 1 or 2, wherein:

11. The linear carbonate has the chemical structure (II): 【Chemistry 3】 [In the formula, R ５ and R ６ may be the same or different and are both selected from unsubstituted, branched or unbranched aliphatic; substituted or unsubstituted, branched or unbranched haloaliphatic; or substituted or unsubstituted, branched or unbranched haloheteroaliphatic chains containing 1 to 10 carbon atoms.

12. The cyclic carbonate has the chemical structure (III): 【Chemistry 4】 [In the formula, R ７ wherein R is a heterocyclic ring linking two oxygen atoms and is selected from an unsubstituted, unbranched aliphatic; a substituted or unsubstituted, unbranched halo aliphatic; or a substituted or unsubstituted, unbranched haloheteroaliphatic chain containing 1 to 10 carbon atoms.

13. 2. The electrochemical cell of claim 1, wherein the molar ratio of linear carbonate to cyclic carbonate is from 0:1 to 10:

1.

14. 2. The electrochemical cell of claim 1, wherein the molar ratio of linear carbonate to cyclic carbonate is from 1:6 to 1:

3.

15. 2. The electrochemical cell of claim 1 wherein the linear carbonate is dimethyl carbonate or ethyl methyl carbonate.

16. 2. The electrochemical cell of claim 1 wherein the cyclic carbonate is fluoroethylene carbonate.

17. The electrochemical cell of claim 1 , wherein the electrochemical cell further comprises a salt.

18. 3. The electrochemical cell of claim 1 or 2, further comprising a second electrode.

19. 10. The electrochemical cell of claim 1 , wherein the first electrode is a lithium intercalation cathode.

20. 20. The electrochemical cell of claim 18, wherein the second electrode comprises lithium.

21. 21. The electrochemical cell of claim 20, wherein the second electrode comprises lithium metal or a lithium metal alloy.

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