Cosalt systems with solvents containing sulfonyl groups, electrolytes made therefrom, and electrochemical devices made using such electrolytes

Abstract

An electrolyte for an electrochemical device having an alkali metal anode having an anode active material comprising an alkali metal is disclosed, wherein the electrolyte includes at least one sulfonyl solvent and a co-salt system. The co-salt system includes a relatively high concentration of a lithium cation primary salt and a relatively low concentration of a secondary salt. The secondary salt and its concentration are selected to increase the solubility of the primary salt. The concentration of the secondary salt can be increased to increase the solubility of the primary salt until the presence of the secondary salt begins to decrease the overall performance of the electrolyte. The primary salt can include two or more lithium cation salts, and the secondary salt can include two or more salts.

Description

[0001] Relevant application data This application claims the benefit of priority to U.S. Provisional Patent Application Serial No. 63 / 558,023, filed February 26, 2024, entitled “Co-Salt Systems with Sulfonyl-Containing Solvents, Electrolytes Made Therewith, and Electrochemical Devices Made Using Such Electrolytes,” which is incorporated herein by reference in its entirety.

[0002] Areas of publicly available content This disclosure generally relates to the field of electrolytes for use in electrochemical devices. In particular, this disclosure relates to co-salt systems having sulfonyl solvents, electrolytes made therefrom, and electrochemical devices made using such electrolytes.

[0003] background Lithium-ion batteries are widely used in many applications, such as portable electronic devices and electric vehicles. However, existing lithium-ion batteries with graphite anodes do not always meet the diverse performance requirements of certain applications. The energy density of lithium-ion batteries has approached its theoretical energy density boundary. Using batteries with a 375 mAh g⁻¹… -1 The high specific capacity of graphite anodes is a major reason for the relatively low energy density of existing lithium-ion batteries, and therefore, the exploration of new anode materials may lead to improvements in the performance of these batteries. In recent years, lithium metal anodes have gained attention due to their relatively high specific capacity (3860 mAh g⁻¹). -1 and the lowest potential (0 V relative to Li / Li) + Therefore, lithium metal anodes have attracted a lot of attention.

[0004] However, lithium metal anode technology faces several challenges, particularly relatively short cycle life and lithium dendrite formation. The cycle life of lithium metal batteries is related to the coulombic efficiency (CE) of lithium metal plating / stripping on the anode side of the battery. Despite significant efforts to improve the performance of lithium metal batteries, most electrolytes developed to date have relatively low CE values ​​(<99.4%), thus resulting in relatively short battery cycle life.

[0005] Overview of publicly available content An electrolyte for an electrochemical device having an alkali metal anode having an alkali metal-containing anolyte active material, wherein the electrolyte comprises at least one sulfonyl solvent, a primary salt, and a secondary salt, wherein the primary salt is a Li cation salt and is at a first concentration, and wherein the secondary salt has a second concentration lower than the first concentration.

[0006] Alternatively or alternatively, the initial concentration of the primary salt is greater than 1 molarity.

[0007] Alternatively or alternatively, the second concentration of the secondary salt is between 0.1% and 30% by weight.

[0008] Alternatively or alternatively, the primary salt is LiFSI, and the secondary salt is LiTFSI.

[0009] Alternatively or alternatively, the primary salt is LiFSI, and the secondary salt is KFSI.

[0010] Alternatively or alternatively, the primary salt is LiFSI, and the secondary salt is LiHFDF.

[0011] Alternatively, the primary salt is LiFSI, and the anion of the secondary salt is TFSI. - .

[0012] Alternatively, the primary salt is LiFSI, and the anion of the secondary salt is FSI. - .

[0013] Alternatively, the primary salt is LiFSI, and the secondary salt anion is HFDF. - .

[0014] Alternatively or alternatively, the cation of the secondary salt is selected from the group consisting of: Li, Na, K, Rb, Cs, Ag, Mg, and In.

[0015] Alternatively or alternatively, the anion of the secondary salt is selected from the group consisting of: tetrafluoroborate (BF4), hexafluorophosphate (PF6), difluorophosphate (DFP), cyclodifluoromethane-1,1-bis(sulfonyl)imide (DMSI), 4,4,5,5-tetrafluoro-1,3,2-dithiazolyl-1,1,3,3-tetraoxide (CTFSI), hexamethyldisilazide (HMDS), and difluoro(oxalate)borate (DFOB).

[0016] Alternatively or alternatively, the sulfonyl solvent is a sulfonamide solvent.

[0017] Alternatively or additionally, the sulfonyl group includes at least one sulfonyl (-SO2-) group, each sulfonyl (-SO2-) group having a double bond between each oxygen atom.

[0018] Alternatively or alternatively, the electrolyte has a total salt concentration ranging from about 1.0 M to about 5.5 M.

[0019] Alternatively or alternatively, the electrolyte has a total salt concentration ranging from about 1.0 M to about 4.5 M.

[0020] Alternatively or additionally, the electrolyte has a salt-solvent molar ratio in the range of about 1:7 to about 1:1.

[0021] An electrochemical cell is provided, comprising an alkali metal anode having an alkali metal-containing anolyte active material; a cathode; a separator located between the alkali metal anode and the cathode; and any electrolyte as described herein, operatively connected to each of the alkali metal anode and the cathode.

[0022] Alternatively or alternatively, a multicell battery is provided, comprising more than one electrochemical cell as described herein; a pair of output terminals; and an electrical connection that electrically connects more than one electrochemical cell to the pair of output terminals.

[0023] A method for preparing an electrolyte for a lithium metal battery cell is disclosed. The method includes selecting a sulfonyl solvent; selecting a primary salt having a lithium cation; dissolving the primary salt in the solvent to form a primary salt solution having a primary salt concentration; selecting a secondary salt; and dissolving the secondary salt in the primary salt solution to form a co-salt solution having a secondary salt concentration. The secondary salt concentration is selected such that it increases the primary salt concentration up to a peak secondary salt concentration beyond which the overall performance of the electrolyte for the lithium metal battery cell deteriorates.

[0024] Alternatively or alternatively, the overall performance of the electrolyte used in a lithium metal battery cell is determined based on the number of battery cycles and cycle life in the absence of a short circuit.

[0025] Furthermore, an electrolyte for an electrochemical device is provided, the electrochemical device having an alkali metal anode having an alkali metal-containing anode active material, wherein the electrolyte comprises at least one sulfonyl solvent, a primary salt and a secondary salt, wherein the primary salt comprises lithium cations and has a primary salt concentration, and wherein the secondary salt has a second salt concentration lower than the primary salt concentration.

[0026] Alternatively or concurrently, the sulfonyl solvent is one or more solvents selected from the group consisting of: CH2=CHSO2F, CH2=CHSO2CF3, (CH3)2NSO2F, FSO2N(CH3)SO2F, (CH3)(CH2=CHCH2)NSO2N(CH3)2, CH3CH=CHSO2N(CH3)(CH2CH3), C6H4FSO2CH2CF3, FCH2SO2CH=CHCH2F, CH2FCH=CHCF2SO2N(SO2F)2, FSO2N(CH3)(CH2CH3), FSO2N(CH2CH3)2 and CF3SO2F.

[0027] Alternatively or additionally, the sulfonyl solvent is one or more solvents selected from the group consisting of: CH2SO2N(CH3)(SO2CH2-), CF2SO2N(CH2CH=CH2)(CF2), (FCH2=CH)CHSO2N(CH3)CH(CH=CH2), CH2SO2N(CH3)CH2CH2, CH2CH2SO2N(CH2CH3)CH2CH2 and CF2SO2N(CH3)SO2CF2.

[0028] Alternatively or alternatively, the sulfonyl solvent is one or more solvents selected from the group consisting of: FSO2N[(CH2)2OCH3]2, FSO2N[(CH2)2OCH3][CH3], CF3SO2N[(CH2)2OCH3]2 and CF3SO2N[(CH2)2OCH3][CH3].

[0029] Alternatively or alternatively, the sulfonyl solvent is one or more solvents selected from the group consisting of FSO2N(CH2)4, CF3SO2N(CH2)4 and FSO2N(CH2CH2)2O.

[0030] Alternatively or concurrently, the anion of the secondary salt is selected from the group consisting of borate anions, sulfonamide anions, sulfonamide anions, phosphate anions, amide anions, and antimonate anions.

[0031] Alternatively or concurrently, the primary salt is selected from the group consisting of: LiFSI, LiTFSI, lithium (fluorosulfonyl)(trifluoromethanesulfonyl)amide, lithium bis(pentafluoroethanesulfonyl)imide, lithium cyclodifluoromethane-1,1-bis(sulfonyl)imide, 4,4,5,5-tetrafluoro-1,3,2-dithiazolyl-1,1,3,3-tetraoxide, lithium 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonylimide, lithium perchlorate, lithium tetrafluoroborate, lithium hexafluorophosphate, lithium hexafluoroantimonyate, lithium trifluoromethanesulfonate, lithium 2-trifluoromethyl-4,5-dicyanoimidazolium, lithium tetracyanoborate, lithium bis(oxalate)borate, lithium difluoro(oxalate)borate, lithium difluoro(bis(oxalate)phosphate), lithium polysulfide, lithium difluorophosphate, LiFSI-polymer and LiTFSI-polymer.

[0032] Alternatively or concurrently, the secondary salt is selected from the group consisting of: LiFSI, LiTFSI, lithium (fluorosulfonyl)(trifluoromethanesulfonyl)amide, lithium bis(pentafluoroethanesulfonyl)imide, lithium cyclodifluoromethane-1,1-bis(sulfonyl)imide, 4,4,5,5-tetrafluoro-1,3,2-dithiazolyl-1,1,3,3-tetraoxide, lithium 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonylimide, lithium perchlorate, lithium tetrafluoroborate, lithium hexafluorophosphate, lithium hexafluoroantimonyate, lithium trifluoromethanesulfonate, lithium 2-trifluoromethyl-4,5-dicyanoimidazolium, lithium tetracyanoborate, lithium bis(oxalate)borate, lithium difluoro(oxalate)borate, lithium difluoro(bis(oxalate)phosphate), lithium polysulfide, lithium difluorophosphate, LiFSI-polymer and LiTFSI-polymer. Brief description of the attached diagram For the purpose of illustrating this disclosure, the accompanying drawings illustrate aspects of one or more embodiments of this disclosure. However, it should be understood that this disclosure is not limited to the precise arrangements and tools shown in the drawings, in which: Figure 1 It is a graph of capacity retention relative to cycle number determined for pouch cells under fast charging conditions according to the present disclosure, wherein one group of cells contains a single salt electrolyte and another group of cells contains a dual salt electrolyte. Figure 2 This is a graph showing the capacity retention relative to the number of cycles for lithium nickel manganese cobalt pouch cells containing a single-salt electrolyte and lithium nickel manganese cobalt pouch cells containing electrolytes with two salts. Figure 3 This is a bar graph showing the cathode CE percentage of a 3 / 4 layer copper-nickel-manganese-cobalt (NMC) anodeless cell containing 1) a single salt electrolyte and 2) a co-salt electrolyte; Figure 4A This is a graph showing the discharge capacity of a Li+ NMC pouch cell containing a single salt electrolyte and a pouch cell containing a co-salt electrolyte relative to the number of cycles. Figure 4B It is about Figure 4A A graph depicting the coulombic efficiency of a Li+ NMC battery relative to the number of cycles; Figure 5A This is a schematic cross-sectional view of an electrochemical energy storage battery manufactured in accordance with the present disclosure; Figure 5B This is a schematic diagram of an energy storage battery system manufactured in accordance with the present disclosure; Figure 6 It is a graph showing the discharge capacity of batteries with dual-salt electrolytes and batteries containing single-salt electrolytes relative to the number of cycles. Figure 7A This is a graph showing the percentage of discharge capacity relative to the number of cycles for a Li+ NMC pouch cell containing a single salt electrolyte, a pouch cell containing a first dual-salt electrolyte, and a pouch cell containing a second dual-salt electrolyte under fast-charge testing; and Figure 7B yes Figure 7A A graph showing the percentage of reverse coulombic efficiency (RCE) of different pouch cells relative to the number of cycles.

[0034] Detailed Explanation In the context of lithium metal batteries, the limited cycle life is partly attributed to the low CE of the lithium anode, which is detrimental to batteries with most conventional electrolytes during cycling. Furthermore, some conventional electrolytes are stable relative to the lithium metal anode but oxidatively unstable with respect to the 4V cathode material, especially at temperatures above room temperature (e.g., > ~20°C). Some conventional electrolytes can remain in the liquid phase and maintain moderate conductivity at room temperature and higher temperatures (e.g., >45°C), but they do not perform well at low temperatures (e.g., <0°C) due to salt precipitation, phase separation, and electrolyte freezing.

[0035] The electrolytes disclosed herein, comprising a co-salt system in a sulfonyl-containing solvent, can lead to fewer side reactions with lithium, resulting in a reduction in lithium deposition surface area, a significant increase in the CE of lithium plating / stripping, suppression of lithium dendrite growth, and minimization of solvent oxidative decomposition at high voltages (>4.5 V) and / or high temperatures (>45 °C). These electrolytes can be used individually and in various combinations over a wide temperature range to provide significant improvements in cycle life, as well as high-temperature and low-temperature stability. The cycle stability of these sulfonyl-containing co-salt electrolytes has been demonstrated in different test schemes. Lithium metal batteries and lithium metal accumulators incorporating these sulfonyl-containing co-salt electrolytes can exhibit improved cycle life, energy density, and safety.

[0036] An electrolyte for an electrochemical device is disclosed, the device comprising an alkali metal anode having an anolyte containing an alkali metal, wherein the electrolyte comprises at least one sulfonyl solvent and a co-salt system. The co-salt system comprises a relatively high concentration of a primary Li cation salt and a relatively low concentration of a secondary salt. The secondary salt and its concentration are selected to increase the solubility of the primary salt. The concentration of the secondary salt may be increased to increase the solubility of the primary salt until the presence of the secondary salt begins to degrade the overall performance of the electrolyte. The primary salt may comprise two or more Li cation salts selected from those disclosed below, and the secondary salt may comprise two or more salts selected from those disclosed below.

[0037] In some implementations, the molar concentration of the primary salt is greater than 1 molar concentration.

[0038] In some implementations, the concentration of the secondary salt is between 0.1% by weight and 30% by weight.

[0039] In some embodiments, the primary salt is lithium bis(fluorosulfonyl)imide (LiFSI), and the secondary salt is lithium bis(trifluoromethane)sulfonylimide (LiTFSI).

[0040] In some embodiments, the primary salt is LiFSI and the secondary salt is potassium bis(fluorosulfonyl)imide (KFSI).

[0041] In some embodiments, the primary salt is LiFSI, and the secondary salt is lithium 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonylimide (LiHFDF).

[0042] In some embodiments, the cation of the secondary salt is selected from the group consisting of: Li, Na, K, Rb, Cs, Ag, Mg, and In.

[0043] In some embodiments, the anion of the secondary salt is selected from the group consisting of: bis(fluorosulfonyl)imide (FSI), bis(trifluoromethanesulfonyl)imide (TFSI), tetrafluoroborate (BF4), hexafluorophosphate (PF6), difluorophosphate (DFP), hexafluoropropane-1,3-disulfonylimide (HFDF), cyclodifluoromethane-1,1-bis(sulfonyl)imide (DMSI), 4,4,5,5-tetrafluoro-1,3,2-dithiazolyl-1,1,3,3-tetraoxide (CTFSI), hexamethyldisilazane (HMDS), and difluoro(oxalate)borate (DFOB).

[0044] In some implementations, the solvent is a sulfonamide solvent.

[0045] In some aspects, this disclosure relates to sulfonyl-containing cosalt electrolytes for use in electrochemical devices, such as primary and secondary batteries, supercapacitors, and others. The sulfonyl-containing cosalt electrolytes of this disclosure are particularly effective for use in secondary alkali metal batteries (AMBs), such as lithium metal batteries (LMBs), where the anode is non-intercalated (e.g., plated / stripped type) and comprises an alkali metal (e.g., lithium (Li), sodium (Na), potassium (K)) or alloy thereof as the anode active material.

[0046] The sulfonyl cosalt electrolyte may contain A) at least one sulfonyl solvent, which comprises molecules each including at least one sulfonyl (-SO2-) group, each molecule having a double bond (i.e., O=S=O) between each oxygen atom and sulfur atom, along with two substituents R. n (n = 2), and a nitrogen atom optionally bonded to at least one SO2 group; B) a primary (or major) Li cation salt at a relatively high concentration, preferably more than 1 mole, most commonly LiFSI; and C) at least one additional secondary salt at a concentration lower than that of the primary salt, preferably ranging from as low as 0.1 wt% to as high as 30 wt%. Secondary salts may contain a variety of metal cations and various anions, including Li, Na, K, Rb, Cs, Ag, Mg, or In, and anions including FSI, TFSI, tetrafluoroborate (BF4), hexafluorophosphate (PF6), difluorophosphate (DFP), hexafluoropropane-1,3-disulfonylimide (HFDF), cyclodifluoromethane-1,1-bis(sulfonyl)imide (DMSI), 4,4,5,5-tetrafluoro-1,3,2-dithiazolyl-1,1,3,3-tetraoxide (CTFSI), hexamethyldisilazane (HMDS), and difluoro(oxalate)borate (DFOB), as well as other anions. Detailed examples of the chemical structures of certain components of the sulfonyl-containing co-salt systems of this disclosure are presented below.

[0047] The sulfonyl-containing cosalt electrolytes of this disclosure may include a sulfonyl-containing solvent, at least two cosalts suitable for the intended electrochemical device, and optionally one or more other components, such as one or more additives and / or diluents, which are added to improve one or more properties or characteristics of the sulfonyl-containing cosalt electrolyte without altering the fundamental properties and characteristics of the sulfonyl-containing cosalt electrolyte without such additives. In the context of AMB, at least one salt will typically include the associated alkali metal as a cation. Further, non-exhaustive examples of cosalt combinations for the sulfonyl-containing cosalt electrolytes of this disclosure are presented below.

[0048] The benefits to AMBs (including LMBs) resulting from the use of the sulfonyl-containing cosalt electrolyte of this disclosure include, individually and / or in various combinations thereof, depending on the circumstances discussed. The sulfonyl-containing cosalt electrolyte of this disclosure can exhibit extremely high stability to alkali metal anodes (e.g., Li-metal anodes) (e.g., alkali metal (e.g., Li) plating / stripping coulombic efficiency (CE) greater than about 99.0% or greater than about 99.5%) and high oxidation resistance (e.g., oxidation voltage greater than about 4.3 V or greater than about 4.8 V), which can lead to improved cycle performance relative to AMBs (including LMBs) utilizing sulfonyl-only solvents, solvent systems, or conventional non-sulfonyl solvent systems. The sulfonyl-containing cosalt electrolyte can provide very high chemical and electrochemical stability at both the cathode and anode in AMBs such as LMBs, enhanced wide-temperature performance, non-flammability, low cost, high safety, and / or good compatibility with battery manufacturing and processing. While the sulfonyl cosalt electrolytes of this disclosure are particularly useful for AMB, their uses are not limited thereto.

[0049] Not bound by any particular theory, the embodiments of the sulfonyl-containing co-salt electrolytes of this disclosure are currently considered to function in any one or more of a variety of ways, depending on the specific co-salt added to the sulfonyl solvent. For example, one of the TFSI salts may function by increasing the solubility of the primary salt without requiring an additional solvent or co-solvent. As another example, one of the HFDF salts may function by altering the coordination structure of the Li cation, resulting in preferential reduction of the primary salt anion, which may lead to an improved interfacial layer on the surface of the Li metal anode. As yet another example, one of the FSI salts may function by increasing the stability of the cathode. When two or more salts are dissolved in a sulfonyl solvent to produce an electrolyte as described herein, other co-salts among the various co-salts discussed below may have the same or other mechanisms for improving electrolyte performance.

[0050] As used herein, the primary salt is the salt with the highest concentration and is selected based on its effectiveness for a given application (e.g., as part of the electrolyte in an AMB). This effectiveness can be increased by increasing the solubility of the primary salt, as disclosed herein, which can be achieved by including a secondary salt at a relatively low concentration. For a given application (i.e., a specific battery), the secondary salt will be less effective than the primary salt, and therefore at a certain threshold concentration, the secondary salt can lead to a reduction in the overall effectiveness of the co-salt electrolyte. In the most preferred embodiment, the concentration of the secondary salt is selected such that the peak effectiveness of the electrolyte is achieved (i.e., the maximum benefit is obtained from the increased solubility of the primary salt before further increases in the secondary salt concentration begin to reduce this effectiveness).

[0051] Exemplary sulfonyl solvents for co-salt electrolyte systems The sulfonyl co-salt system of this disclosure comprises at least one sulfonyl solvent having any of the following common chemical structures: Structure 1 (R1-SO2-R2): in: Each of R1 and R2 can be: -F; -CF3; -N(SO2F)2; -N(CH3)SO2F;-N[(CH2) x CH3)][(CH2) y CH3)] (x = 0 to 3, y = 0 to 3); -N[(CH2) x CH3][(CH2) y CH=CH(CH2) z -H] (x = 0 to 2, y = 1 to 3, z = 0 to 3); -(CH2) x CH=CH(CH2) y -H (x = 0 to 3, y = 0 to 3); -C6H 5-x F x (x = 0 to 5); -(CH2) x (CH 2-y F y ) z CH 3-w F w (x = 0 to 2, y = 1 to 2, z = 0 to 2, w = 0 to 3); -(CH2) x (CH 2-y F y ) z F (x = 0 to 2, y = 0 to 2, z = 0 to 2); or -(CH2) x CH=CH(CH 2-y F y ) z F (x = 0 to 3, y = 0 to 2, z = 0 to 2); and R1 ≠ R2 or R1 = R2.

[0052] The following are exemplary sulfonyl solvents having general structure 1: 1) R1 is -CH=CH2, R2 is -F, and the solvent is CH2=CHSO2F; 2) R1 is -CH=CH2, R2 is -CF3, and the solvent is CH2=CHSO2CF3; 3) R1 is -N(CH3)2, R2 is -F, and the solvent is (CH3)2NSO2F; 4) R1 is -NCH3SO2F, R2 is F, and the solvent is FSO2N(CH3)SO2F; 5) R1 is -N(CH3)(CH2CH=CH2), R2 is -N(CH3)2, and the solvent is (CH3)(CH2=CHCH2)NSO2N(CH3)2; 6) R1 is -CH=CHCH3, R2 is -N(CH3)(CH2CH3), and the solvent is CH3CH=CHSO2N(CH3)(CH2CH3); 7) R1 is -C6H4F, R2 is -CH2CF3, and the solvent is C6H4FSO2CH2CF3; 8) R1 is -CH2F, R2 is -CH=CHCH2F, and the solvent is FCH2SO2CH=CHCH2F; 9) R1 is -CF2CHCH=CHCH2F, R2 is -N(SO2F)2, and the solvent is CH2FCH=CHCF2SO2N(SO2F)2; 10) R1 is -C6H5, R2 is F, and the solvent is C6H5SO2F; 11) R1 is F, R2 is N(CH3)(CH2CH3), and the solvent is FSO2N(CH3)(CH2CH3); 12) R1 is F, R2 is N(CH2CH3)2, and the solvent is FSO2N(CH2CH3)2; and 13) R1 is CF3, R2 is F, and the solvent is CF3SO2F.

[0053] The compounds of the aforementioned examples of structure 1 include: .

[0054] Other solvents may include structure 2 (-R3-SO2N-R5SO2-R4-) and structure 3 (-R3-SO2N-(R5)R4-): [Structure 2] [Structure 3] in: R3 and R4 are connected in a ring shape by covalent bonds as shown in structures 2 and 3 above, respectively; Each of R3 and R4 can be any of the following: -CF2-; -CH2-; -CH((CH2)x H 1-y F y )- (x = 0 to 3, y = 0 to 1); -CF((CH2) x H 1-y F y )- (x = 0 to 3, y = 0 to 1); or -CH((CH 2-x F x ) y CH=CH 1-z F z (CH 2-x’ F x’ ) v H 1-w F w )- (x = 0 to 2, x' = 0 to 2, y = 0 to 2, z = 0 to 1, v = 0 to 2, w = 0 to 1); Where R3 ≠ R4 or R3 = R4; and R5 can be any of the following: -(CH2) x CH3 (x = 0 to 3); or -(CH2) x CH=CH2 (x = 1 to 3).

[0055] The following are exemplary sulfonyl solvents having general structure 2 or general structure 3: 1) R3 is -CH2-, R4 is -CH2-, R5 is -CH3, and the solvent is CH2SO2N(CH3)(SO2CH2-); 2) R3 is -CF2-, R4 is -CF2-, R5 is -CH2CH=CH2, and the solvent is -CF2SO2N(CH2CH=CH2)(CF2)-; 3) R is -CH(CH=CH2F)-, R4 is -CH(CH=CH2)-, R5 is -CH3, and the solvent is -(FCH2=CH)CHSO2N(CH3)CH(CH=CH2)-; 4) R3 is -CH2-, R4 is -CH2CH2-, R5 is -CH3, and the solvent is -CH2SO2N(CH3)CH2CH2-; 5) R3 is -CH2CH2-, R4 / R7 is -CH2CH2-, R5 is -CH2CH3, and the solvent is -CH2CH2SO2N(CH2CH3)CH2CH2-; and 6) R3 is -CF2-, R4 is CF2, R5 is CH3, and the solvent is -CF2SO2N(CH3)SO2CF2-.

[0056] Exemplary compounds of structure 2 include: .

[0057] Exemplary compounds of structure 3 include: .

[0058] Other solvents may include structure 4 (R6-SO2N-(R7)(R8)): in: R6 can be -(CH2) x (CH 2-y F y ) z F (x = 0 to 2, y = 0 to 2, z = 0 to 2); R7 can be -(CH2) x O(CH2) y CH3 (x=2 to 4, y=0 to 2); and R8 can be: -(CH2) x CH3 (x=0 to 3); or -(CH2) x O(CH2) y CH3 (x=2 to 4, y=0 to 2).

[0059] The following are exemplary sulfonyl solvents having the general structure 4: 1) R6 is -F, R7 is -(CH2)2OCH3, R8 is -(CH2)2OCH3, and the solvent is FSO2N[(CH2)2OCH3]2; 2) R6 is -F, R7 is -(CH2)2OCH3, R8 is -CH3, and the solvent is FSO2N[(CH2)2OCH3][CH3]; 3) R6 is -CF3, R7 is -(CH2)2OCH3, R8 is -(CH2)2OCH3, and the solvent is CF3SO2N[(CH2)2OCH3]2; and 4) R6 is -CF3, R7 is -(CH2)2OCH3, R8 is -CH3, and the solvent is CF3SO2N[(CH2)2OCH3][CH3].

[0060] Exemplary compounds of structure 4 include: .

[0061] Other solvents may include structure 5 ((R9)R 10 -SO2): in: R9 can be -(CH2) x (CH 2-y F y ) z F (x = 0 to 2, y = 0 to 2, z = 0 to 2); and R 10 The inner ring consists of a nitrogen-containing ring, an oxygen-containing ring, a hydrocarbon-only ring, or a mixture of nitrogen and oxygen rings, and R 10 It could be: -N(CH2)4 (1-pyrrolidinyl five-membered ring); -N(CH2)5 (1-piperidinyl six-membered ring); -N(CH2CH2)2O (4-morpholino six-membered ring); -C5H9 (cyclopentane); -C6H 11 (Cyclohexane); -C4H7O (2-tetrahydrofuran or 3-tetrahydrofuran); or Its fluorinated analogues.

[0062] The following are exemplary sulfonyl solvents with general structure 5: 1) R9 is -F, R 10 It is -N(CH2)4, and the solvent is FSO2N(CH2)4 (five-membered ring); 2) R9 is -CF3, R 10 It is -N(CH2)4 (five-membered ring), and the solvent is CF3SO2N(CH2)4 (five-membered ring); 3) R9 is -F, R 10 It is -N(CH2CH2)2O (six-membered ring), and the solvent is FSO2N(CH2CH2)2O (six-membered ring).

[0063] Exemplary compounds of structure 5: .

[0064] The sulfonyl co-salt system of this disclosure may comprise one of these sulfonyl solvents or a mixture of two or more of the sulfonyl solvents disclosed herein, including both linear sulfonyl solvents and cyclic sulfonyl solvents, wherein each solvent comprises, for example, from about 0.05% to about 99.95% of the total amount of the sulfonyl solvent by volume, by weight or by molar ratio, or from about 5% to about 50% of the total amount of the sulfonyl solvent by volume, by weight or by molar ratio.

[0065] Exemplary salts for co-salt electrolyte systems As mentioned above, the sulfonyl-containing cosalt systems and sulfonyl-containing cosalt electrolytes of this disclosure comprise one or more non-primary (or secondary) salts mixed with a primary salt in a solvent to form a cosalt system or cosalt electrolyte. As mentioned, examples of cations that can be used in these sulfonyl-containing cosalt systems and sulfonyl-containing cosalt electrolytes include, but are not limited to, alkali metal cations, alkaline earth metal cations, transition metal cations, and post-transition metal cations. Examples of anions that can be used in sulfonyl-containing cosalt systems and sulfonyl-containing cosalt electrolytes include, but are not limited to, borate-containing anions and derivatives, sulfonamide-containing anions and derivatives, sulfonylimide-containing anions and derivatives, phosphate-containing anions and derivatives, amide-containing anions and derivatives, and antimonate-containing anions and derivatives. The amount of cosalt in the sulfonyl-containing cosalt system can, for example, range from about 0.05% to about 99.95% of the total salt by volume, by weight, or by molar ratio. The general chemical structures of specific exemplary cosalts that can be used as cosalts are presented below.

[0066] Exemplary borate anions Borate cosalts can, for example, have the following structure: 6 (B-R1(R2)(R3)(R4)): Within structure 6, each of R1, R2, R3, and R4 can independently be -H, -F, or -OC. x H y CH z F a (x = 1-8, y = 2x, z = 0-3, a = 3-z), -OCOCOO (cyclic oxalate structure), or any combination of the listed structures.

[0067] Exemplary sulfonamide-containing anions The co-salt containing sulfonamide can, for example, have the following structure 7 (R5-SO2N-R6): Within structure 7, each of R5 and R6 can independently be -H, -F, or -CH. x F y (x = 0-3, y = 3-x), -C x H y F z CH a F b (x = 1-8, y = 2x, z = 2x - y, a = 0-3, b = 3-a), -C x H y [OCz H a ] n (x = 1-8, y = 2x, z = 1-4, a = 2z, n = 1-8) or any combination of the listed structures.

[0068] Exemplary sulfonamide-containing anions The co-salt containing sulfonamide can, for example, have the following structure 8 (R7-SO2N-SO2-R8): Within structure 8, each of R7 and R8 can independently be -H, -F, or -CH. x F y (x = 0-3, y = 3-x), -C x H y F z CH a F b (x = 1-8, y = 2x, z = 2x - y, a = 0-3, b = 3-a), -C x H y [OC z H a ] n (x = 1-8, y = 2x, z = 1-4, a = 2z, n = 1-8) or any combination of the listed structures.

[0069] Exemplary phosphate-containing anions Exemplary phosphate-containing co-salts may, for example, have the following structure: 9 (R9-PO2-R 10 ) or Structure 10 (PR 11 (R 12 (R) 13 (R) 14 (R) 15 (R) 16 )): [Structure 9] [Structure 10] In each of structures 9 and 10, R9, R 10 R 11 R 12 R 13 R 14 R 15 and R 16 Each of these can independently be any of the following: -F, -CH x F y(x = 0-3, y = 3-x), -OCOCOO (cyclic oxalate structure), -OC x H y F z CH a F b (x = 1-8, y = 0-16, F = 16-x, a = 0-3, b = 3-a), -SiC3H9, or any combination of the listed structures.

[0070] Exemplary amide anion Amide cosalts can have the following structure 11 (R 17 -NR 18 ): Within structure 11, R 17 and R 18 Each of these can independently be any one of the following: -H, -SiC3H9, -C x H y F z CH a F b (x = 1-8, y = 0-16, z = 16-y, a = 0-3, b = 3-a) or any combination listed here.

[0071] Exemplary antimonate co-salts Antimonate co-salts can, for example, have the following structure: 12(Sb-R) 19 (R 20 (R) 21 (R) 22 (R) 23 (R) 24 )): Within structure 12, R 19 R 20 R 21 R 22 R 23 and R 24 It can be any of the following: -F, -CH x F y (x = 0-3, y = 3-x), -C x H y F z CH a F b (x = 1-8, y = 0-16, z = 16-y, a = 0-3, b = 3-a) or any combination listed here.

[0072] Exemplary sulfonyl cosalt electrolytes In some embodiments, one or more of the following salts may be combined with any of the sulfonyl-containing solvents described above to form a co-salt electrolyte: lithium sulfonylimide [e.g., linear structures: lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium (fluorosulfonyl)(trifluoromethanesulfonyl)-amide (LiFTA), lithium bis(pentafluoroethanesulfonyl)imide (LiBETI), and cyclic structures: lithium cyclodifluoromethane-1,1-bis(sulfonyl)imide (LiDMSI), 4,4,5,5-tetrafluoro-1,3,2-dithiazolyl-1,1,3,3-lithium tetraoxide (LiCTFSI), 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonyl] Lithium imide (LiHFDF), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium hexafluorophosphate (LiPF6), lithium hexafluoroantimonyate (LiSbF6), lithium trifluoromethanesulfonate (LiTF), lithium 2-trifluoromethyl-4,5-dicyanimidazolium (LiTDI), lithium tetracyanoboronate (LiB(CN)4), lithium bis(oxalate)borate (LiBOB), lithium difluoro(oxalate)borate (LiDFOB), lithium difluoro(bis(oxalate)phosphate) (LiDFOP), lithium polysulfides, lithium difluorophosphate (LiDFP), other organolithium salts (e.g., organolithium, lithium alkoxides, lithium amides, lithium imide, lithium thiols, lithium phosphonates, etc.), and lithium polymer salts (e.g., LiFSI-polymer and LiTFSI-polymer). Furthermore, the lithium cation in any of the salts mentioned above can be replaced by different metal cations such as Na, K, Rb, Cs, Mg, Zn, Al, Ag, and In.

[0073] In some embodiments, two or more of the salts listed above may be part of a sulfonyl-containing co-salt electrolyte with a concentration ranging from about 0.1 M to about 5.5 M. In some embodiments, the salt concentration ranges from about 0.5 M to about 4.5 M. It should also be noted that the sulfonyl-containing solvent co-salt system of this disclosure is suitable for lithium-ion batteries and lithium-ion rechargeable batteries. In some examples of lithium-ion batteries and lithium-ion rechargeable batteries, the salt-solvent molar ratio can range from about 1:7 to about 1:1.

[0074] Exemplary electrochemical device: Embodiments of this disclosure include sulfonyl-containing cosalt electrolytes, each of which is manufactured using any one or more of the sulfonyl-containing solvent systems described above, including any exemplary mixtures; and two or more salts, including lithium-based salts and / or mixtures thereof listed above, and any salts or mixtures thereof based on alkali metals other than lithium, such as sodium or potassium.

[0075] Embodiments of this disclosure also include electrochemical devices, such as batteries and supercapacitors, each comprising a co-salt electrolyte having a sulfonyl-containing solvent manufactured according to aspects of this disclosure. Exemplary batteries include LMBs, lithium-ion batteries, and batteries based on alkali metals other than lithium (i.e., AMBs), such as sodium metal batteries or potassium metal batteries, and other batteries. Those skilled in the art will understand that many different configurations of electrochemical devices having a sulfonyl-containing solvent co-salt electrolyte manufactured according to this disclosure can be utilized, and all suitable conventional electrochemical device configurations are incorporated herein as the basis for electrochemical devices manufactured according to this disclosure, including conventional configurations of electrochemical devices comprising a sulfonyl-containing solvent co-salt electrolyte manufactured according to this disclosure.

[0076] As an example, Figure 5A The figure illustrates an exemplary energy storage battery 100 manufactured according to aspects of this disclosure. Those skilled in the art will readily understand that the energy storage battery 100 may be, for example, a battery cell (e.g., a lithium metal battery cell or a battery based on another alkali metal chemistry, etc.) or a supercapacitor battery. Furthermore, those skilled in the art will readily understand that... Figure 5A Only some basic functional components of battery 100 are illustrated, and real-world examples of batteries such as secondary storage batteries or supercapacitors will typically be shown in a stacked or wound configuration comprising multiple instances of layered components. Furthermore, those skilled in the art will understand that energy storage battery 100 will include other components, such as one or more seals, thermal shutdown layers and / or vents, and other components provided for ease of illustration. Figure 5A Not shown in the image.

[0077] In this example, battery 100 includes an anode 104 and a cathode 108 spaced apart from each other, and includes corresponding active materials 104a and 108a and a pair of corresponding current collectors 104c and 108c. Current collectors 104c and 108c are electrically connected to corresponding electrical terminals 112b and 112a, such as tabs in a pouch configuration. At least one porous dielectric separator 116 is located between the anode 104 and the cathode 108 to electrically separate the anode and cathode, but allow ions of a co-salt electrolyte 120 having a sulfonyl-containing solvent to flow through it. As will be understood, electrolyte 120 can be any co-salt electrolyte having a sulfonyl-containing solvent described herein, or can be manufactured by a person skilled in the art using only the disclosure (including the appended claims) as guidance without excessive experimentation.

[0078] As those skilled in the art will understand, depending on the type and design of the battery 100, each of the anode 104 and cathode 108 comprises one or more suitable materials, which are chosen based on whether the battery is being charged or discharged via a co-salt electrolyte 120 having a sulfonyl group in the form of a solvent that gains or loses ions. Each of the active materials 104a and 108a can be any suitable material used for the anode 104 and cathode 108, respectively. Examples of anode active material 104a may include alkali metal-based materials such as pure lithium, pure sodium, pure potassium, and their alloys, among others. Examples of cathode active material 108a include crystalline oxides containing multiple amounts of cobalt, nickel, and manganese, among many other cathode active materials. Each of the current collectors 104c and 108c can be made of any suitable conductive material, such as copper or aluminum, or any combination thereof. The porous separator 116 can be made of any suitable dielectric material, such as polymers (e.g., PP, PE, PP / PE blends, etc.), among others; and can be coated or uncoated as needed to meet certain designs. It can be used to construct... Figure 5A Various battery and supercapacitor configurations of the battery 100 are known in the art. The novelty of the battery 100 lies in the co-salt electrolyte 120 having a sulfonyl-containing solvent, manufactured according to this disclosure, if any such known configuration is used.

[0079] Figure 5B The figure illustrates an exemplary multi-cell battery 150 manufactured according to the present disclosure. In this example, the battery 150 includes more than one electrochemical storage cell 154 (e.g., 154a, 154b to 154) electrically connected to each other via suitable electrical connections 158. n The supplied batteries are 154a to 154a. nThe quantity can be any number suitable for a specific application, such as 2 to 100 or more. The electrical connection 158 can be for connecting batteries 154a to 154... n The batteries 150 are interconnected by any connection required to meet the design requirements of the application discussed. For example, electrical connection 158 can be a series connection, a parallel connection, or a combination of both. Furthermore, batteries 154a to 154... n The batteries can be grouped into one or more groups, and each such group can be part of a corresponding battery module. In such cases, electrical connection 158 can include electrical connections between modules. Those skilled in the art will readily understand the types and means of physical connections required to implement electrical connection 158, which can include, but are not limited to, tab-to-tab connections, busbar connections, wiring connections, and harness connections, among others. Fundamentally, there is no limitation on the type of electrical connection that can be part of electrical connection 158. In this example, electrical connection 158 is electrically connected to a pair of battery output terminals 162a and 162b, which will be connected to an electrical load and / or power source (both not shown) during battery deployment. Not shown are many other components that may be included on the exemplary battery 150, such as, but not limited to, a battery management system, a sensor system, an emergency disconnect unit, and a module controller, among others.

[0080] Experimental results This section contains exemplary formulations of sulfonyl cosalt electrolytes manufactured according to this disclosure, and results of cycle life tests from batteries containing these electrolytes compared to batteries containing a single salt electrolyte. These exemplary formulations are merely illustrative, and those skilled in the art will be able to readily manufacture other formulations without excessive experimentation when using this disclosure as guidance.

[0081] Combinations of N,N-dimethylsulfonyl fluoride (DMSF), lithium bis(fluorosulfonyl)imide (LiFSI), and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) have been developed to form exemplary sulfonyl-containing co-salt systems according to this disclosure. Importantly, it has been demonstrated that pouch electrochemical cells containing LiFSI + LiTFSI in a DMSF co-salt electrolyte can suppress short circuits for over 175 fast-charge cycles. This is in comparison to tests of similar cells containing sulfonyl solvents and single-salt electrolytes, which only experience short circuits after 110 cycles. Test results revealing this ~50% improvement are presented in... Figure 1 middle, Figure 1This is a graph showing the capacity retention of a pouch cell relative to the number of cycles under fast-charging conditions (1.3 C–0.5 C for charging and 0.4 C for discharging). The first cell (its result is shown as the dark line marked 10 on the graph) is a Li+Ni-metal-Cobalt (NMC) pouch cell containing an electrolyte with a single salt, LiFSI in a single solvent, N,N-dimethylsulfonyl fluoride (DMSF). The second cell (its result is shown as the lighter line marked 20 on the graph) is a Li+NMC pouch cell containing an electrolyte with two salts, LiFSI + lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), which is also dissolved in DMSF as a single solvent. As can be seen in the graph, the pouch cell with the dual-salt electrolyte exhibits greater cycle stability and greater resistance to short circuits than the pouch cell with the single-salt electrolyte. Batteries containing a LiFSI + LiTFSI co-salt electrolyte exhibited improved cycle life compared to single-salt electrolytes. The salts in the co-salt electrolyte consisted of 3.3 M LiFSI (primary) and 0.06 M LiTFSI (secondary) in DMSF solvent. The salts in the single-salt electrolyte had a concentration of 2.9 M LiFSI in DMSF solvent.

[0082] Combinations of LiFSI and LiTFSI co-salts in DTMS solvent have been developed to form the co-salt system according to this disclosure. Importantly, it has been demonstrated that pouch-type electrochemical cells containing the LiFSI + LiFSI co-salt electrolyte can achieve a cycle life exceeding 175 C / 3 charge-C / 3 discharge cycles. This is in comparison to tests of similar cells containing LiFSI as the sole salt, which only experienced an 80% capacity decrease after 140 cycles. Test results revealing this ~28% improvement are presented in… Figure 2 middle, Figure 2 This is a graph showing the capacity retention (percentage) relative to the number of cycles for a Li+NMC pouch cell containing an electrolyte with a single salt (LiFSI) in N,N-dimethyltrifluoromethanesulfonamide (DTMS) (the results are shown by the lighter line marked 11 on the graph) and a pouch cell containing an electrolyte with two salts, namely LiFSI+LiTFSI in DTMS (the results are shown by the dark line marked 21 on the graph). Figure 2 The battery with a LiFSI + LiTFSI co-salt electrolyte exhibits improved cycle life compared to a battery containing a single-salt electrolyte. The salts in the co-salt electrolyte have concentrations of 2.1 M LiFSI and 1 M LiTFSI in DTMS solvent, respectively. The single-salt electrolyte has a concentration of 2.1 M LiFSI in DTMS solvent.

[0083] The cathode coulombic efficiency (CE) of an electrochemical cell is directly related to its cycle life. Figure 3 This is a bar graph showing the average cathode coulombic efficiency (CE) percentage of a 3 / 4 layer copper (Cu)-NMC anodeless cell under both C / 3 charging and C / 3 discharging conditions, for cells containing a single-salt electrolyte (LiFSI in DMSF, bar 13) and a co-salt electrolyte (LiFSI + KFSI in DMSF, bar 23). The graph illustrates the improved cathode coulombic efficiency (CE) of the cell with the LiFSI + KFSI co-salt electrolyte. The salt concentrations used in the co-salt-based electrolyte are 4.0 M LiFSI and 0.5 M KFSI in DMSF. The salt concentration used in the single-salt electrolyte is 2.9 M LiFSI in DMSF.

[0084] In production Figure 1 and Figure 2 The same type of Li-NMC battery used in the tests summarized in the paper was used to test the LiFSI + LiTFSI co-salt electrolyte relative to the LiFSI single salt electrolyte. Figure 4A The graph shows the discharge capacity versus cycle number of a Li+NMC pouch cell containing a single salt electrolyte with LiFSI in DMSF (results are shown as the dark line marked 14) and a pouch cell containing a co-salt electrolyte, namely LiFSI + LiTFSI in DMSF (results are shown as the lighter line marked 24). The cycle stability of the cell containing the LiFSI + LiTFSI co-salt electrolyte is better than that of the cell containing the LiFSI single salt electrolyte. Figure 4B It is about Figure 4A The graphs depicting the coulombic efficiency of Li+ NMC batteries relative to the number of cycles show the results for pouch cells containing a single salt (LiFSI) electrolyte as line 15, and the results for batteries containing a co-salt electrolyte (LiFSI + LiTFSI) as line 25. Figure 4B The results show that batteries containing a LiFSI + LiTFSI cosalt electrolyte exhibit a slower decrease in coulombic efficiency compared to batteries containing a LiFSI single-salt electrolyte. This is consistent with... Figure 4A The cycling stability shown is consistent. In this test, the solvent used for the co-salt electrolyte was DMSF, and the salt had concentrations of 3.3 M LiFSI and 0.06 M LiTFSI. The same solvent was used in the single-salt electrolyte, and the salt had a concentration of 2.9 M LiIFSI.

[0085] Figure 6This is a graph showing the discharge capacity versus cycle number of a Li+ NMC pouch cell (results shown as the lighter line marked 26) containing an electrolyte with a LiFSI + 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonylimide lithium (LiHFDF) dual-salt system in N-ethyl-N-methylsulfonyl fluoride (EMSF) + DMSF solvent at 25°C under 1C charging and C / 3 discharging conditions, and a cell containing a LiFSI single-salt electrolyte with the same solvent system (results shown as the dark line marked 16). Figure 6 As can be seen, all batteries containing a co-salt electrolyte (i.e., LiFSI (3.0M) + LiHFDF (0.8M) co-salt electrolyte in DMSF) exhibit better cycle stability and do not experience short circuits under fast-charging conditions. In contrast, batteries containing a single salt electrolyte (i.e., LiFSI (2.9M)-DMSF electrolyte) show worse cycle stability and only experience short circuit issues after 120 cycles.

[0086] Figure 7A This is a graph showing the percentage of discharge capacity relative to the number of cycles for a Li+ NMC pouch cell comprising: 1) a 3.1 M LiFSI single-salt electrolyte (solid lines marked 30a-30c) in a DMSF + N-ethyl-N-methylsulfonyl fluoride (EMSF) cosolvent (volume ratio DMSF:EMSF = 3:1) under fast-charge testing (1.3C-0.5C for charging and 0.4C for discharging); 2) a 3.3 M LiFSI + 0.06 M LiTFSI dual-salt electrolyte (dashed lines marked 31a-31c) contained in DMSF; and 3) a 3.4 M LiFSI + 0.75 M KFSI dual-salt electrolyte (dotted dashed lines marked 32a-32c) contained in DMSF. Figure 7A As can be seen, by adjusting the dual-salt characteristics and concentration, further improvements to the dual-salt electrolyte under fast-charging conditions can be achieved. In this embodiment, by changing the secondary salt in DMSF from LiTFSI to KFSI, short circuits under fast-charging conditions were eliminated, and the cycle life was significantly improved to nearly 250 cycles.

[0087] Figure 7BThis is a graph showing the percentage of reverse coulombic efficiency (RCE) relative to the number of cycles for pouch cells with different electrolytes. The results (shown as the solid line marked 33) of a Li+ NMC pouch cell containing a 3.1M LiFSI single-salt electrolyte in a DMSF + N-ethyl-N-methylsulfonyl fluoride (EMSF) cosolvent (volume ratio DMSF:EMSF = 3:1) will be compared with those of a pouch cell with a dual-salt electrolyte. The first pouch cell contains a dual-salt electrolyte of 3.3M LiFSI + 0.06M LiTFSI in DMSF (shown as the dashed line marked 34), and the second pouch cell contains a dual-salt electrolyte of 3.4M LiFSI + 0.75M KFSI in DMSF (shown as the dotted dashed line marked 35). Compared to pouch cells with a single salt electrolyte, both types of pouch cells with dual salt electrolytes typically exhibit reduced RCE growth and delayed or no short circuits.

[0088] It should be noted that throughout this disclosure, the term “about” when used with a corresponding numerical value refers to ±20% of that value, typically ±10% of that value, typically ±5% of that value, and more typically ±2% of that value. In some embodiments, the term “about” may mean the value itself.

[0089] Various modifications and additions can be made without departing from the spirit and scope of the invention. Features of each of the various embodiments described above can be suitably combined with features of other described embodiments to provide multiple combinations of features in associated new embodiments. Furthermore, while various individual embodiments have been described above, what has been described herein is merely illustrative of the application of the principles of the invention. Additionally, although specific methods herein may be described and / or described as being performed in a particular order, the order is highly variable within the scope of ordinary art to achieve aspects of this disclosure. Therefore, this description is intended to be made by way of example only and not to otherwise limit the scope of the invention.

[0090] Exemplary embodiments have been disclosed above and illustrated in the accompanying drawings. Those skilled in the art will understand that various changes, omissions, and additions can be made to the specific disclosure herein without departing from the spirit and scope of the invention.

Claims

1. An electrolyte for use in an electrochemical device, the electrochemical device having an alkali metal anode, the alkali metal anode having an anode active material comprising an alkali metal, the electrolyte comprising: At least one sulfonyl solvent; A primary salt, wherein the primary salt is a lithium (Li) cation salt and is at a first concentration; and Secondary salt, wherein the secondary salt has a second concentration lower than the first concentration.

2. The electrolyte according to claim 1, wherein the first concentration of the primary salt is greater than 1 molar concentration.

3. The electrolyte of claim 2, wherein the second concentration of the secondary salt is between 0.1% by weight and 30% by weight.

4. The electrolyte according to claim 3, wherein the primary salt is lithium bis(fluorosulfonyl)imide (LiFSI) and the secondary salt is lithium bis(trifluoromethane)sulfonylimide (LiTFSI).

5. The electrolyte according to claim 3, wherein the primary salt is LiFSI and the secondary salt is potassium bis(fluorosulfonyl)imide (KFSI).

6. The electrolyte according to claim 3, wherein the primary salt is LiFSI and the secondary salt is lithium 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonylimide (LiHFDF).

7. The electrolyte according to claim 3, wherein the primary salt is LiFSI, and the anion of the secondary salt is bis(trifluoromethanesulfonyl)imide (TFSI). - ).

8. The electrolyte according to claim 3, wherein the primary salt is LiFSI, and the anion of the secondary salt is bis(fluorosulfonyl)imide (FSI). - ).

9. The electrolyte according to claim 3, wherein the primary salt is LiFSI, and the anion of the secondary salt is hexafluoropropane-1,3-disulfonylimide (HFDF). - ).

10. The electrolyte according to any one of claims 7-9, wherein the cation of the secondary salt is selected from the group consisting of: Li, Na, K, Rb, Cs, Ag, Mg and In.

11. The electrolyte according to claim 3, wherein the anion of the secondary salt is selected from the group consisting of: tetrafluoroborate (BF4), hexafluorophosphate (PF6), difluorophosphate (DFP), cyclodifluoromethane-1,1-bis(sulfonyl)imide (DMSI), 4,4,5,5-tetrafluoro-1,3,2-dithiazolyl-1,1,3,3-tetraoxide (CTFSI), hexamethyldisilazane (HMDS), and difluoro(oxalate)borate (DFOB).

12. The electrolyte according to any one of claims 1-11, wherein the at least one sulfonyl solvent is a sulfonamide solvent.

13. The electrolyte according to any one of claims 1-11, wherein at least one sulfonyl group comprises at least one sulfonyl (-SO2-) group, each sulfonyl (-SO2-) group having a double bond between each oxygen atom.

14. The electrolyte according to any one of claims 1-13, wherein the electrolyte has a total salt concentration from about 1.0 M to about 5.5 M.

15. The electrolyte according to any one of claims 1-13, wherein the electrolyte has a total salt concentration from about 1.0 M to about 4.5 M.

16. The electrolyte according to any one of claims 1-13, wherein the electrolyte has a salt-solvent molar ratio in the range of about 1:7 to about 1:

1.

17. An electrochemical battery, comprising: Alkali metal anode, which has an anode active material containing alkali metal; cathode; A partition is located between the alkali metal anode and the cathode; as well as The electrolyte according to any one of claims 1 to 16 is operatively connected to each of the alkali metal anode and the cathode.

18. A multi-cell storage battery, comprising: More than one electrochemical cell according to claim 17; A pair of output terminals, and An electrical connection portion that electrically connects the more than one electrochemical cell to the pair of output terminals.

19. A method for preparing an electrolyte for a lithium metal battery cell, comprising: Choose a sulfonyl solvent; Select a primary salt having a lithium cation; The primary salt is dissolved in the solvent to form a primary salt solution with a primary salt concentration; Choose secondary salts; as well as The secondary salt is dissolved in the primary salt solution to form a co-salt solution with a secondary salt concentration, wherein the secondary salt concentration is selected such that the secondary salt concentration increases the primary salt concentration up to a peak secondary salt concentration, beyond which the overall performance of the electrolyte of the lithium metal battery cell decreases.

20. The method of claim 19, wherein the overall performance of the electrolyte used in the lithium metal battery cell is determined based on lifetime cycles and cycle life in the absence of short circuits.

21. An electrolyte for an electrochemical device having an alkali metal anode having an alkali metal-containing anode active material, the electrolyte comprising: At least one sulfonyl solvent; A primary salt, wherein the primary salt comprises a Li cation and has a primary salt concentration; and Secondary salt, wherein the secondary salt has a second salt concentration lower than that of the primary salt.

22. The electrolyte according to claim 21, wherein the sulfonyl solvent is one or more solvents selected from the group consisting of: CH2=CHSO2F, CH2=CHSO2CF3, (CH3)2NSO2F, FSO2N(CH3)SO2F, (CH3)(CH2=CHCH2)NSO2N(CH3)2, CH3CH=CHSO2N(CH3)(CH2CH3), C6H4FSO2CH2CF3, FCH2SO2CH=CHCH2F, CH2FCH=CHCF2SO2N(SO2F)2, FSO2N(CH3)(CH2CH3), FSO2N(CH2CH3)2 and CF3SO2F.

23. The electrolyte according to claim 21, wherein the sulfonyl solvent is one or more solvents selected from the group consisting of: CH2SO2N(CH3)(SO2CH2-), CF2SO2N(CH2CH=CH2)(CF2), (FCH2=CH)CHSO2N(CH3)CH(CH=CH2), CH2SO2N(CH3)CH2CH2, CH2CH2SO2N(CH2CH3)CH2CH2 and CF2SO2N(CH3)SO2CF2.

24. The electrolyte according to claim 21, wherein the sulfonyl solvent is one or more solvents selected from the group consisting of: FSO2N[(CH2)2OCH3]2, FSO2N[(CH2)2OCH3][CH3], CF3SO2N[(CH2)2OCH3]2 and CF3SO2N[(CH2)2OCH3][CH3].

25. The electrolyte according to claim 21, wherein the sulfonyl solvent is one or more solvents selected from the group consisting of: FSO2N(CH2)4, CF3SO2N(CH2)4 and FSO2N(CH2CH2)2O.

26. The electrolyte according to claim 21, wherein the anion of the secondary salt is selected from the group consisting of borate anions, sulfonamide anions, sulfonamide anions, phosphate anions, amide anions, and antimonate anions.

27. The electrolyte according to claim 21, wherein the primary salt is selected from the group consisting of: LiFSI, LiTFSI, lithium (fluorosulfonyl)(trifluoromethanesulfonyl)amide, lithium bis(pentafluoroethanesulfonyl)imide, lithium cyclodifluoromethane-1,1-bis(sulfonyl)imide, 4,4,5,5-tetrafluoro-1,3,2-dithiazolyl-1,1,3,3-tetraoxide, lithium 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonylimide, lithium perchlorate, lithium tetrafluoroborate, lithium hexafluorophosphate, lithium hexafluoroantimonyate, lithium trifluoromethanesulfonate, lithium 2-trifluoromethyl-4,5-dicyanoimidazolium, lithium tetracyanoborate, lithium bis(oxalate)borate, lithium difluoro(oxalate)borate, lithium difluoro(bis(oxalate)phosphate), lithium polysulfide, lithium difluorophosphate, LiFSI-polymer, and LiTFSI-polymer.

28. The electrolyte according to claim 21, wherein the secondary salt is selected from the group consisting of: LiFSI, LiTFSI, lithium (fluorosulfonyl)(trifluoromethanesulfonyl)amide, lithium bis(pentafluoroethanesulfonyl)imide, lithium cyclodifluoromethane-1,1-bis(sulfonyl)imide, 4,4,5,5-tetrafluoro-1,3,2-dithiazolyl-1,1,3,3-tetraoxide, lithium 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonylimide, lithium perchlorate, lithium tetrafluoroborate, lithium hexafluorophosphate, lithium hexafluoroantimonyate, lithium trifluoromethanesulfonate, lithium 2-trifluoromethyl-4,5-dicyanoimidazolium, lithium tetracyanoborate, lithium bis(oxalate)borate, lithium difluoro(oxalate)borate, lithium difluoro(bis(oxalate)phosphate), lithium polysulfide, lithium difluorophosphate, LiFSI-polymer, and LiTFSI-polymer.

Images