Epoxy-modifying additives for lithium-ion batteries

Abstract

Disclosed are electrolytes containing epoxide-functionalized organic compounds and epoxide-functionalized organic compound additives suitable for use in electrochemical energy storage devices that are useful for reducing battery resistance, extending cycle life, and improving high temperature performance. TIFF2023542818000022.tif109151

Description

[Technical Field]

[0001] cross reference This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 63 / 071,020, filed August 27, 2020, which is incorporated herein by reference in its entirety.

[0002] Field The present disclosure relates to epoxide-functionalized organic compounds useful for reducing battery resistance, extending cycle life, and improving high temperature performance; electrolytes containing the epoxide-functionalized organic compound additives; and electrochemical energy storage devices containing these electrolytes. [Background technology]

[0003] background Li-ion batteries are widely used in home appliances, electric vehicles (EVs), and energy storage systems (ESSs) and smart grids. Recently, Li-ion batteries with voltages above 4.35 V have gained importance due to their higher capacity and subsequent energy density. However, the stability of positive electrode materials at these potentials is reduced by increased oxidation. This can lead to electrochemical oxidation of the material, resulting in gas generation and reduced battery performance. Positive electrode active materials capable of lithium ion intercalation / deintercalation can dissolve in the nonaqueous electrolyte, causing structural destruction of the material and increasing interfacial resistance. These Li-ion batteries are also typically exposed to extreme temperatures during operation. The SEI (solid-electrolyte interface) layer formed on the negative electrode gradually decomposes at high temperatures, thus triggering more irreversible reactions and resulting in capacity loss. Similarly, the CEI (positive electrode-electrolyte interface) also loses stability at high temperatures. These reactions occur at the positive and negative electrodes during cycling and are generally more severe at higher temperatures due to faster kinetics. Next-generation Li-ion batteries used in consumer electronics, EVs, and ESS will require significant improvements in electrolyte components compared to current state-of-the-art Li-ion batteries.

[0004] The primary function of an electrolyte is the shuttling of positive and negative ions between battery electrodes. Historically, researchers have focused on developing battery electrodes, with limited development of electrolytes. Traditional Li-ion batteries use carbonate-based electrolytes, which have a large potential window through which lithium ions can be transported. These electrolytes require functional additives to passivate the negative electrode and form a stable SEI, as well as additives to stabilize the positive electrode. At the same time, additives must be designed and developed to enable stable and safe cycling of high-pressure, high-energy Li-ion batteries.

[0005] As the industry moves toward high-energy cathode materials for high-energy batteries, stable, efficient, and safe cycling of the battery over a wide voltage window is necessary. Li-ion battery electrolytes can be tailored based on their application by adding different cosolvents and additives. This tunability has enabled the development of different additives for high-voltage stability and safety of Li-ion cells. Another aspect of high-voltage Li-ion battery electrolyte development is the design and optimization of additives that stabilize the cathode by polymerizing to form CEI. The development of such additives may enable higher-energy cathode materials and thus improve the energy storage capacity of Li-ion cells.

[0006] Herein, we report epoxide-functionalized organic compounds as additives for lithium-ion batteries. As electrolyte additives, these functionalized molecules enable the formation of CEIs, which protect the cathode and electrolyte from decomposition at high potentials. Cells containing this additive in the electrolyte enable safe, long-cycle, and high-energy lithium-ion batteries.

[0007] Korean Patent KR 1535071 (Patent Document 1) of Chungnam National University Industry Collaboration Foundation reports the use of 2-oxiraneacetonitrile as an element of electrolyte for lithium secondary batteries. Therefore, it is necessary to incorporate new additives to improve the performance of lithium ion batteries. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Korean Patent No. KR 1535071 Summary of the Invention

[0009] overview According to one aspect of the present disclosure, there is provided an electrolyte for an electrochemical energy storage device, comprising: an epoxide-functionalized organic compound additive; an aprotic organic solvent system; and a metal salt.

[0010] According to another aspect of the present disclosure, there is provided an electrolyte for an electrochemical energy storage device, comprising: an epoxide-functionalized organic compound additive; an aprotic organic solvent system; a metal salt; and at least one additional additive.

[0011] According to another aspect of the present disclosure, there is provided an electrochemical energy storage device comprising: a positive electrode; a negative electrode; a separator; and an electrolyte comprising an epoxide-functionalized organic compound additive, an aprotic organic solvent system, and a metal salt.

[0012] In accordance with another aspect of the present disclosure, there is provided an electrolyte for an electrochemical energy storage device, comprising: an epoxide-functionalized organic compound additive; an aprotic organic solvent system; a metal salt; and at least one additional additive; wherein the aprotic organic solvent comprises a linear or cyclic carbonate, a carboxylic acid ester, a nitrite, an ether, a sulfone, a sulfoxide, a ketone, a lactone, a dioxolane, a glyme, a crown ether, a siloxane, a phosphate ester, a phosphite, a mono- or polyphosphazene, or a mixture thereof.

[0013] According to another aspect of the present disclosure, there is provided an electrolyte for an electrochemical energy storage device, comprising: an epoxide-functionalized organic compound additive; an aprotic organic solvent system; a metal salt; and at least one additional additive; wherein the cation of the metal salt is aluminum, magnesium, or an alkali metal such as lithium or sodium.

[0014] According to another aspect of the present disclosure, there is provided an electrolyte for an electrochemical energy storage device, comprising: an epoxide-functionalized organic compound additive; an aprotic organic solvent system; a metal salt; and at least one additional additive; wherein the additional additive comprises a compound containing at least one unsaturated carbon-carbon bond, a carboxylic acid anhydride, a sulfur-containing compound, a phosphorus-containing compound, a boron-containing compound, a silicon-containing compound, or a mixture thereof.

[0015] According to another aspect of the present disclosure, there is provided an electrochemical energy storage device electrolyte comprising: an aprotic organic solvent system; a metal salt; and at least one epoxide-functionalized organic compound additive of Formula I, II, III, IV, V, or VI herein.

[0016] According to another aspect of the present disclosure, there is provided an electrochemical energy storage device comprising: a positive electrode; a negative electrode; an electrolyte of the present disclosure; and a separator.

[0017] These and other aspects of the present disclosure will become apparent upon review of the following detailed description and appended claims. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a graph showing the dQ / dV profiles of electrolytes tested in the NMC811 / Gr cell of the present disclosure; [Figure 2] FIG. 2 is a graph showing the dQ / dV profiles of electrolytes tested in the NMC622 / Gr cell of the present disclosure; [Figure 3]FIG. 3 shows the room temperature cycle life characteristics of electrolytes tested in NMC622 / Gr cells of the present disclosure; and [Figure 4] FIG. 4 shows the 45° C. cycle life characteristics of the electrolytes tested in the NMC622 / Gr cell of the present disclosure; [Figure 5] FIG. 5 shows the cycle life characteristics of a 1.6 Ah NMC811 / Gr cell at 25° C. during cycling at 1 C for charge and discharge; and [Figure 6] FIG. 6 is a graph of capacity retention of 5.0 Ah NMC811 / Gr cells containing CE101, CE102, and EE101. DETAILED DESCRIPTION OF THE INVENTION

[0019] Detailed Description The technology of the present disclosure relates generally to lithium-ion (Li-ion) battery electrolytes. In particular, the present disclosure is directed to epoxide-functionalized organic compounds containing at least one oxygen-phosphorus bond, electrolytes containing these additive materials, and electrochemical energy storage devices containing the electrolytes.

[0020] This disclosure describes a Li-ion battery electrolyte containing an electrolyte additive that can overcome the challenge of cathode stability in Li-ion batteries, particularly those containing high-nickel-content cathode materials at high voltages. Current state-of-the-art Li-ion batteries contain cathode materials with low nickel content, operating at high voltages, or high nickel content but operating at low voltages. State-of-the-art electrolytes are tailored to these conditions, and researchers have recently begun to focus on enabling high-nickel, high-voltage battery cathodes with novel electrolyte formulations. There is a need to develop electrolytes for cycling Li-ion cells with high-voltage, high-nickel cathodes. This technology is based on an innovative additive containing an epoxide-functionalized organic compound that can improve the stability of high-voltage, high-energy cathodes. The electrolyte additive forms a unique cathode-electrolyte interface (CEI) that does not overly passivate the cathode when used with light loads. Additionally, the improved CEI improves high-temperature performance and storage stability without adversely affecting performance at room temperature.

[0021] In one embodiment, the electrochemical energy storage device electrolyte comprises: a) an aprotic organic solvent system; b) a metal salt; c) an epoxide-functionalized organic compound material additive; and d) at least one additional additive.

[0022] In one aspect of the present disclosure, the molecular structures of at least six epoxide-functionalized organic compound additives of formula I, II, III, IV, V, or VI are shown below: TIFF0007761285000001.tif19662 formula, X is oxygen or sulfur; n is an integer ranging from 1 to 8; R1, R2, R3, R4, and R5 are Independently, halogen, C1~C 12 Substituted or unsubstituted alkyl group or C6-C 14 an oxygen or sulfur atom further bonded to the aryl group; Independently C1~C 12 Substituted or unsubstituted alkyl group or C6-C 14 aryl group wherein any hydrogen or carbon atom can be unsubstituted or independently substituted with an epoxide, halogen, alkyl, alkoxy, perfluorinated alkyl, silyl, siloxy, silane, sulfoxide, amide, azo, ether, or thioether group, or combinations thereof; R6 and R7 are Independently, C1~C 12 Substituted or unsubstituted alkyl group or C6-C 14 an oxygen or sulfur atom further bonded to the aryl group; Independently C1~C 12 Substituted or unsubstituted alkyl group or C6-C 14 aryl group wherein any hydrogen or carbon atom can be unsubstituted or independently substituted with an epoxide, halogen, alkyl, alkoxy, perfluorinated alkyl, silyl, siloxy, silane, sulfoxide, amide, azo, ether, or thioether group, or combinations thereof; and R8, R9, and R10 are independently hydrogen, C1-C 12 It is selected from alkyl, heteroalkyl, perfluoroalkyl, alkenyl, aryl or alkoxy groups.

[0023] Specific examples of molecules of the present disclosure are shown below: TIFF0007761285000002.tif12128R=F, Glycidyl difluorophosphite R=CH3, glycidyl dimethyl phosphite R=CF3, glycidyl bis(trifluoromethyl)phosphite R=CH2CH3, glycidyl diethyl phosphite R = CH2CF3, glycidyl bis(2,2,2-trifluoroethyl) phosphite R = CF2CF3, glycidyl bis(perfluoroethyl) phosphite R=CH(CH3)2, glycidyl diisopropyl phosphite R = CH(CF3)2, glycidyl bis(1,1,1,3,3,3-hexafluoro-2-propyl) phosphite TIFF0007761285000003.tif209165TIFF0007761285000004.tif45165These examples are merely illustrative and are not intended to limit the disclosure of the appended claims.

[0024] The addition of epoxide-functionalized organic compounds to Li-ion battery systems allows for the polymerization or oxidation of the epoxide at the surface of the cathode at elevated temperatures. The resulting polyether film coordinates with the cathode material and inhibits further oxidative degradation of remaining electrolyte components that would otherwise occur in contact with the cathode material. The inclusion of phosphorus-oxygen bonds ensures good coordination with high-nickel, high-energy cathode materials.

[0025] The present disclosure also includes methods for the synthesis of epoxide-functionalized organic compounds and the use of such molecules in lithium-ion battery electrolytes, which provide greater stability to the electrolyte and positive electrode at higher operating potentials.

[0026] In one aspect of the present disclosure, the electrolyte further comprises 10% to 30% by weight of a lithium salt, such as Li(AsF6); Li(PF6); Li(CF3CO2); Li(C2F5CO2); Li(CF3SO3); Li[N(CP3SO2)2]; Li[C(CF3SO2)3]; Li[N(SO2C2F5)2]; Li(ClO4); Li(BF4); Li(PO2F2); Li[PF2(C2O4)2]; Li[PF4C2O4]; lithium alkyl fluorophosphate; Li[B(C2O4)2]; Li[BF2C2O4]; Li2[B 12 Z 12-j H j ];Li2[B 10 X 10-j' H j' or a mixture of any two or more of these, where Z is independently a halogen in each occurrence, j is an integer from 0 to 12, and j' is an integer from 1 to 10.

[0027] In one aspect of the present disclosure, the electrolyte solution further comprises an aprotic organic solvent system selected from linear or cyclic carbonates, carboxylic acid esters, nitrites, ethers, sulfones, sulfoxides, ketones, lactones, dioxolanes, glymes, crown ethers, siloxanes, phosphate esters, phosphites, mono- or polyphosphazenes, or mixtures thereof, in the range of 60% to 90% by weight.

[0028] Examples of aprotic solvents for forming the electrolyte include, but are not limited to, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, dipropyl carbonate, propylene carbonate, ethylene carbonate, fluoroethylene carbonate, bis(trifluoroethyl) carbonate, bis(pentafluoropropyl) carbonate, trifluoroethyl methyl carbonate, pentafluoroethyl methyl carbonate, heptafluoropropyl methyl carbonate, perfluorobutyl methyl carbonate, trifluoroethyl ethyl carbonate, pentafluoroethyl ethyl carbonate, heptafluoropropyl ethyl carbonate, perfluorobutyl methyl carbonate, Examples of suitable solvents include fluorobutyl ethyl carbonate, fluorinated oligomers, methyl propionate, ethyl propionate, butyl propionate, dimethoxyethane, triglyme, dimethylvinylene carbonate, tetraethylene glycol, dimethyl ether, polyethylene glycol, triphenyl phosphate, tributyl phosphate, hexafluorocyclotriphosphazene, 2-ethoxy-2,4,4,6,6-pentafluoro-1,3,5,2-5,4-5,6-5 triazatriphosphinine, triphenyl phosphite, sulfolane, dimethyl sulfoxide, ethyl methyl sulfone, ethyl vinyl sulfone, allyl methyl sulfone, divinyl sulfone, fluorophenyl methyl sulfone, and gamma butyrolactone.

[0029] In one aspect of the present disclosure, the electrolyte solution further comprises at least one additional additive to protect the electrode and the electrolyte solution from deterioration.Therefore, the electrolyte solution of the present technology may comprise an additive that is reduced or polymerized on the surface of the electrode to form a passivation film on the surface of the electrode.In some embodiments, the electrolyte solution of the present technology further comprises a mixture of two kinds of additives.

[0030] In one embodiment, the additive is a substituted or unsubstituted linear, branched, or cyclic hydrocarbon containing at least one oxygen atom and at least one aryl, alkenyl, or alkynyl group. The passivation film formed from such an additive can also be formed from a substituted aryl compound or a substituted or unsubstituted heteroaryl compound, where the additive contains at least one oxygen atom.

[0031] Representative additives include glyoxal bis(diallyl acetal), tetra(ethylene glycol) divinyl ether, 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane, 2,4,6-triallyloxy-1,3,5-triazine, 1,3,5-triacryloylhexahydro-1,3,5-triazine, 1,2-divinyl furoate, 1,3-butadiene carbonate, 1-vinylazetidin-2-one, 1-vinylaziridin-2-one, 1-vinylpiperidin-2-one, 1-vinylpyrrolidin-2-one, 2,4-divinyl-1,3-dioxane, 2-amino-3-vinylcyclohexanone, 2-amino-3-vinylcyclohexanone, and 2-amino-3-vinylcyclohexanone. -3-Vinylcyclopropanone, 2-amino-4-vinylcyclobutanone, 2-amino-5-vinylcyclopentanone, 2-aryloxy-cyclopropanone, 2-vinyl-[1,2]oxazetidine, 2-vinylaminocyclohexanol, 2-vinylaminocyclopropanone, 2-vinyloxetane, 2-vinyloxy-cyclopropanone, 3-(N-vinylamino)cyclohexanone, 3,5-divinylfuroate, 3-vinylazetidin-2-one, 3-vinylaziridin-2-one, 3-vinylcyclobutanone, 3-vinylcyclopentanone, 3-vinyloxaziridine, 3-vinyloxetane, 3-vinylpyrrolidin-2-one, 2-vinyl-1,3-dioxolane, acrolein diethyl acetal, acrolein dimethyl acetal, 4,4-Divinyl-3-dioxolan-2-one, 4-vinyltetrahydropyran, 5-vinylpiperidin-3-one, allyl glycidyl ether, butadiene monoxide, butyl vinyl ether, dihydropyran-3-one, divinyl butyl carbonate, divinyl carbonate, divinyl crotonate, divinyl ether, divinyl ethylene carbonate, divinyl ethylene silicate, divinyl ethylene sulfate, divinyl ethylene sulfite, divinyl methoxypyrazine, divinyl methyl phosphate, divinyl propylene carbonate, ethyl phosphe The additives include vinyl esters such as vinyl esters of ... For example, the additive may be a (divinyl)-(methoxy)(trifluoro)cyclotriphosphazene, (trivinyl)(difluoro)(methoxy)cyclotriphosphazene, (vinyl)(methoxy)(tetrafluoro)cyclotriphosphazene, (aryloxy)(tetrafluoro)(methoxy)cyclotriphosphazene, (methylsulfonyl)cyclotriphosphazene, or (diaryloxy)(trifluoro)(methoxy)cyclotriphosphazene compound or a mixture of two or more such compounds.

[0032] In some embodiments, the additive is a sulfur-containing compound, a phosphorus-containing compound, a boron-containing compound, a silicon-containing compound, a fluorine-containing compound, a nitrogen-containing compound, a compound containing at least one unsaturated carbon-carbon bond, a carboxylic acid anhydride, or a mixture thereof. In some embodiments, the additive is vinyl carbonate, vinyl ethylene carbonate, or a mixture of any two or more such compounds. Further, the additive is present in an amount ranging from 0.01% to 10% by weight.

[0033] In some embodiments, the additive is a fully or partially halogenated phosphate ester compound, an ionic liquid, or a mixture thereof. Halogenated phosphate esters can include 4-fluorophenyldiphenylphosphate, 3,5-difluorophenyldiphenylphosphate, 4-chlorophenyldiphenylphosphate, trifluorophenylphosphate, heptafluorobutyldiphenylphosphate, trifluoroethyldiphenylphosphate, bis(trifluoroethyl)phenylphosphate, and phenylbis(trifluoroethyl)phosphate. The ionic liquid may include tris(N-ethyl-N-methylpyrrolidinium)thiophosphate bis(trifluoromethylsulfonyl)imide, tris(N-ethyl-N-methylpyrrolidinium)phosphate bis(trifluoromethylsulfonyl)imide, tris(N-ethyl-N-methylpiperidinium)thiophosphate bis(trifluoromethylsulfonyl)imide, tris(N-ethyl-N-methylpiperidinium)phosphate bis(trifluoromethylsulfonyl)imide, N-methyl-trimethylsilylpyrrolidinium bis(trifluoromethylsulfonyl)imide, or N-methyl-trimethylsilylpyrrolidinium hexafluorophosphate. Additionally, the additive may be present in the range of 0.01% to 10% by weight.

[0034] In another aspect of the present disclosure, an electrochemical energy storage device is provided, comprising a positive electrode, a negative electrode, and an electrolyte comprising the ionic liquid described herein. In one embodiment, the electrochemical energy storage device is a lithium secondary battery. In some embodiments, the secondary battery is a lithium battery, a lithium ion battery, a lithium sulfur battery, a lithium air battery, a sodium ion battery, or a magnesium battery. In some embodiments, the electrochemical energy storage device is an electrochemical cell such as a capacitor. In some embodiments, the capacitor is an asymmetric capacitor or a supercapacitor. In some embodiments, the electrochemical cell is a primary cell. In some embodiments, the primary cell is a lithium / MnO2 battery or a Li / poly(carbon monofluoride) battery.

[0035] In one embodiment, a secondary battery is provided that includes a positive electrode and a negative electrode separated from one another by a porous separator and an electrolyte solution described herein.

[0036] Suitable cathodes include, but are not limited to, lithium metal oxides, spinel, olivine, carbon-coated olivine, LiFePO4, LiCoO2, LiNiO2, LiMn 0.5 Ni 0.5 O2, LiMn 0.3 Co 0.3 Ni 0.3 O2, LiMn2O4, LiFeO2, LiNi x Co y Met z O2, A n' B2(XO4)3, vanadium oxide, lithium peroxide, sulfur, polysulfides, lithium carbon monofluoride (LiCF x(also known as ZnO, Mg, Ti, B, Ga, Si, Mn, or Co) or a mixture of any two or more thereof, where Met is Al, Mg, Ti, B, Ga, Si, Mn, or Co; A is Li, Ag, Cu, Na, Mn, Fe, Co, Ni, Cu, or Zn; B is Ti, V, Cr, Fe, or Zr; X is P, S, Si, W, or Mo; and where 0≦x≦0.3, 0≦y≦0.5, and 0≦z≦0.5 and 0≦n′≦0.3. According to some embodiments, the spinel is Li 1+x Mn 2-z Met''' y O 4-m X' n where Met''' is Al, Mg, Ti, B, Ga, Si, Ni, or Co; X' is S or F; and where 0≦x≦0.3, 0≦y≦0.5, 0≦z≦0.5, 0≦m≦0.5, and 0≦n≦0.5. In another embodiment, the olivine is a spinel manganese oxide having the formula: 1+x Fe 1z Met'' y PO 4-m X' n where Met″ is Al, Mg, Ti, B, Ga, Si, Ni, Mn, or Co; X′ is S or F; and where 0≦x≦0.3, 0≦y≦0.5, 0≦z≦0.5, 0≦m≦0.5, and 0≦n≦0.5.

[0037] Suitable negative electrodes include, for example, lithium metal, graphite materials, amorphous carbon, carbon nanotubes, Li4Ti5O 12 , tin alloys, silicon, silicon alloys, intermetallic compounds, or a mixture of any two or more such materials. Suitable graphite materials include natural graphite, artificial graphite, graphitized mesocarbon microbeads (MCMB) and graphite fibers, as well as any amorphous carbon material. In some embodiments, the negative and positive electrodes are separated from each other by a porous separator.

[0038] Lithium battery separators are often microporous polymer films. Examples of polymers for forming the film include polypropylene, polyethylene, nylon, cellulose, nitrocellulose, polysulfone, polyacrylonitrile, polyvinylidene fluoride, polybutene, or copolymers or mixtures of any two or more such polymers. In some examples, the separator is an electron-beam-treated microporous polyolefin separator. The electron treatment can increase the separator's deformation temperature and therefore its thermal stability at high temperatures. Additionally or alternatively, the separator can be a shutdown separator. The shutdown separator can have a trigger temperature above about 130°C to allow the electrochemical cell to operate at temperatures up to about 130°C.

[0039] The present disclosure is further illustrated by reference to the following specific examples, it being understood that these examples are offered by way of illustration and are not intended to limit the scope of the disclosure or the appended claims. [Example]

[0040] Example 1 - Synthesis of oxiran-2-ylmethyl diphenyl phosphate TIFF0007761285000005.tif30138 To a 100 mL three-necked RBF equipped with a stir bar, thermocouple, water-cooled condenser, and N2 inlet, 6 mL of glycidol in dichloromethane (DCM) was added. 2 mL of Et3N in DCM was added to the flask. 3 mL of diphenylphosphoryl chloride in DCM was added to the flask. A small amount of white smoke was observed, and a slight exotherm to 24.1 °C was also observed. The reaction mixture was stirred overnight at room temperature (RT). After stirring the reaction mixture for approximately 15 minutes at RT, some white solid precipitate formed. Deionized (DI) water was added to the flask to dissolve the white solid precipitate. The entire mixture was poured into a separatory funnel. The organic phase was extracted twice with DCM, separated, combined, and dried over MgSO4. The solvent was then removed on a rotary evaporator. 1.8 g of crude oil was recovered. The crude oil was purified by column chromatography on silica gel eluting with DCM to give a pure colorless oil, 0.8 g.

[0041] Example 2 - Synthesis of monooxiranemethylpentachlorophosphazene TIFF0007761285000006.tif20137 Glycidol in 12 mL of MeCN was added to a 100 mL three-necked RBF equipped with a stir bar, thermocouple, water-cooled condenser, and N2 inlet. K3PO4 was added to the flask. K3PO4 was not soluble in MeCN. While stirring at room temperature, phosphonitrilic chloride trimer was added to the flask. The reaction mixture was heated to 60 °C and stirred at 60 °C for 1 day. The reaction mixture turned pink while stirring at 60 °C. The MeCN was then removed on a rotary evaporator, and the remainder of the mixture was transferred to a separatory funnel. Deionized water and DCM were added to the funnel. The organic phase was extracted twice with DCM, separated, combined, and dried over MgSO4. The solvent was removed on a rotary evaporator. Yield: yellow oil, 1.8g.

[0042] Example 3 - Synthesis of Glycidyl Difluorophosphite TIFF0007761285000007.tif16129Step A: Synthesis of glycidyl dichlorophosphite TIFF0007761285000008.tif27166 A 250 mL three-necked flask equipped with a magnetic stir bar, N2 inlet, HCl gas outlet to the base bath, and thermocouple was charged with phosphorus trichloride and DCM (20 mL). The flask was placed in an ice-water bath. With stirring at 5 °C, a solution of glycidol in DCM (5 mL) was added slowly via syringe over 4 h. An exotherm below 15.0 °C was maintained, and no gas evolution was observed. The mixture was allowed to warm slowly to RT, stirred for 1 h, and the solvent was removed by rotary evaporation. Crude yield: 12.2 g (>99%) of a colorless oil. The oil was distilled under reduced pressure: pot, 120 °C; steam, 75 °C; pressure, 1.0 mmHg. Yield: colorless oil, 6.8g (55%).

[0043] Step B: Synthesis of glycidyl difluorophosphite TIFF0007761285000009.tif27166 Antimony(III) fluoride and hexane (25 mL) were added to a 250 mL three-neck flask equipped with a magnetic stir bar, N2 inlet, and thermocouple. The flask was placed in an ice-water bath. With stirring at 5 °C, a solution of the Step A product in hexane (5 mL) was added slowly via syringe. A mild exotherm was observed. The mixture was allowed to warm slowly to RT and stirred for 2 h. A thick yellow oil settled to the bottom (presumably SbCl3). The solvent was separated from the yellow oil and removed by rotary evaporation. Crude yield: colorless oil, 4.4 g (80%). The oil was flushed with nitrogen for 30 min and transferred to a dry vial in a glovebox.

[0044] Example 4 - Electrolyte Formulation for NMC811 / Gr Cell The electrolyte formulation was prepared in a dry argon-filled glove box by mixing all electrolyte components in a glass vial and stirring for 24 hours to ensure complete dissolution of all solids. The epoxide-based additive material was a 3:7 volumetric mixture of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and Li dissolved therein. +A base electrolyte formulation containing 1 M lithium hexafluorophosphate (LiPF6) as the ion-conducting salt is added. Vinylene carbonate (VC) is used as the standard negative electrode SEI-forming additive, and 1,3-propane sultone (PaS) is used as a comparative example. The electrolyte formulation is shown in Table A.

[0045] Table A: Electrolyte Formulations TIFF0007761285000010.tif59166

[0046] Example 5 - Electrochemical Cell Data for NMC811 / Gr Cell The prepared electrolyte formulation was used as the electrolyte in 1.8 Ah Li-ion pouch cells containing NMC811 as the positive electrode active material and graphite as the negative electrode active material. The cell operating voltage window was 4.2 to 2.8 V. 6 g of electrolyte was added to each cell and allowed to soak in the cell for 1 hour. The cells were vacuum sealed and left at room temperature for 24 hours. The cells were then charged to 3.7 V at a C / 50 rate, stored in a 60 °C storage cabinet for 12 hours to open the epoxide, and then degassed and vacuum sealed. After degassing, the cells were charged and discharged twice between 4.2 and 2.8 V at a C / 10 rate. The results are summarized in Table B. The initial capacity loss (iCL) was calculated based on the first cycle coulombic efficiency, and the reported discharge capacity is that of the final cycle of formation. AC-IR is the internal resistance measured at a frequency of 1 kHz. It is clear that the addition of 1 wt% of the epoxide-based additive increases the AC-IR and therefore reduces the initial discharge capacity compared to the comparative example. However, the dQ / dV profile in Figure 1 shows a distinctive SEI layer on the negative electrode surface compared to the comparative example. The dQ / dV profile of EE1 shows a distinctive broad reaction shoulder at 2.75 V, which is not present in the cells with the other electrolytes.

[0047] (Table B) Initial cell data for NMC811 / Gr cells TIFF0007761285000011.tif45160

[0048] The cells were then subjected to a high-temperature storage test. The cells were charged to 100% state of charge at 4.2 V and placed in an environmental chamber set at 60°C. The cells were measured for AC-IR, thickness, and capacity recovery every two weeks. A summary of the results is shown in Table C. As can be seen in Table C, all cells exhibited increased internal resistance, some expansion due to gassing, and capacity loss. However, Representative Example EE1 exhibits improvements in all three key factors compared to the comparative examples, particularly reduced cell thickness growth and improved capacity recovery.

[0049] (Table C) Storage data for NMC811 / Gr cells TIFF0007761285000012.tif46160

[0050] Example 6 - Electrolyte Formulation for NMC622 / Gr Cell The electrolyte formulation was prepared in a dry argon-filled glove box by mixing all electrolyte components in a glass vial and stirring for 24 hours to ensure complete dissolution of all solids. The epoxide-based additive material was a 3:7 volumetric mixture of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and Li dissolved therein. + A base electrolyte formulation containing 1 M lithium hexafluorophosphate "LiPF6" as the ionically conductive salt is added. Vinylene carbonate "VC" and fluoroethylene carbonate "FEC" are used as standard negative electrode SEI-forming additives. The electrolyte formulation is shown in Table D.

[0051] Table D: Electrolyte Formulations TIFF0007761285000013.tif71160

[0052] Example 7 - Electrochemical Cell Data for NMC622 / Gr Cell The prepared electrolyte formulation was used as the electrolyte in 200 mAh Li-ion pouch cells containing lithium nickel manganese cobalt oxide (NMC622) as the positive electrode active material and graphite as the negative electrode active material. 0.9 mL of the electrolyte formulation was added to each cell and allowed to soak in the cell for 1 hour. The cells were vacuum sealed and subjected to a primary charge at 25°C for 10 hours before soaking. The cells were then charged to 3.8 V at a C / 25 rate, degassed, and subsequently vacuum sealed. After degassing, the cells were charged and discharged twice between 4.45 and 3.0 V at a C / 10 rate. The results are summarized in Table E. The initial capacity loss (iCL) was calculated based on the first cycle coulombic efficiency (CE), and the reported discharge capacity is that of the final cycle at a C / 5 rate. AC-IR is the internal resistance measured at a frequency of 1 kHz. With the addition of 1 wt% epoxide-based additive, the initial cell data is very similar to that of the reference electrolyte. However, in the dQ / dV profile of Figure 2, an earlier response is seen with the epoxide additive of the present disclosure.

[0053] (Table E) Initial cell data for NMC622 / Gr cells TIFF0007761285000014.tif38160

[0054] As can be seen from the data in Figures 3 and 4, the EE2 cell exhibits more stable cycle life characteristics during cycling at room temperature and 45°C compared to the CE3 cell. The CE3 cell experiences rapid capacity loss even at RT due to its higher cutoff voltage, while the EE2 cell is more stable. Thus, the disclosed epoxiside-based molecules improve the stability of high-voltage positive electrodes operating at higher cutoff voltages.

[0055] Example 8 - Electrolyte for NMC811 / Gr Cell The epoxide-functional additive was prepared by mixing ethylene carbonate (EC) and ethyl methyl carbonate (EMC) in a 3:7 weight ratio with Li dissolved therein. +A base electrolyte formulation containing 1 M lithium hexafluorophosphate (LiPF6) as the ionically conductive salt is added. Comparative Example 4 (CE4) consists of the base formulation. Specific Example 4 (EE4) uses a representative example molecule of the present disclosure. A summary of the electrolyte components and additives used is provided in Table F.

[0056] Table F: Electrolyte Formulations for NMC811 / Gr Cells TIFF0007761285000015.tif38128

[0057] Specific example 1 has the following structure: TIFF0007761285000016.tif17128

[0058] Example 9 - Electrochemical Cell Data for NMC811 / Gr Cell The prepared electrolyte formulation was used as the electrolyte in 1.6 Ah Li-ion pouch cells containing NMC811 as the positive electrode active material and artificial graphite as the negative electrode active material. The cell operating voltage window was 4.2 to 2.7 V. 6 g of electrolyte was added to each cell and allowed to soak in the cell for 1 hour. The cells were vacuum-sealed and left at room temperature for 24 hours. The cells were then charged to 3.7 V at a C / 25 rate, degassed, and then vacuum-sealed. After degassing, the cells were charged and discharged twice at a C / 10 rate between 4.2 and 2.7 V, and then charged and discharged 300 times at a 1C rate at 25 °C between 4.2 and 2.7 V. Figure 5 shows the cycle life characteristics of the 1.6 Ah NMC811 / Gr cell at 25 °C during cycling at a 1C rate. It is clear that the addition of the epoxide-functional additive significantly improved the cyclability of the NMC811 / Gr cell compared to the comparative example. Capacity retention after 300 cycles is higher for the EE4 cells compared to the CE4 cells, and this data is summarized in Table G.

[0059] (Table G) Data for NMC811 / Gr cells after 300 cycles TIFF0007761285000017.tif39128

[0060] Example 10 - Electrolyte for NMC811 / Gr Cell The epoxide additive was a 3:7 weight ratio mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC), and Li dissolved therein. + A base electrolyte formulation containing 1 M lithium hexafluorophosphate (LiPF6) as the ionically conductive salt is added. Comparative Example 101 (CE101) consists of a base formulation containing vinylene carbonate (VC), and Comparative Example 102 (CE102) contains propane sultone (PaS) along with a VC dosage. Specific Example 101 (EE101) uses a representative molecule of the present disclosure in addition to VC. A summary of the electrolyte components and additives is provided in Table H.

[0061] Table H: Electrolyte Formulations for NMC811 / Gr Cells TIFF0007761285000018.tif77160

[0062] Example 11 - Electrochemical Cell Data for NMC811 / Gr Cell The prepared formulation was used as the electrolyte in 5.0 Ah Li-ion pouch cells containing NMC811 as the positive electrode active material and graphite as the negative electrode active material. The cell operating voltage window was 4.2 to 2.8 V. 15 g of electrolyte was added to each cell and immersed in the cell for 1 hour. After sealing, the cells were charged to 3.7 V at a C / 25 rate, degassed, and then vacuum sealed. After degassing, the cells were charged and discharged twice between 4.2 and 2.8 V at a C / 10 rate, then charged and discharged 600 times between 4.2 and 2.8 V at a 0.5C rate at 25 °C, or subjected to a high-temperature storage test. Figure 6 shows the cycle life characteristics of the 5.0 Ah NMC811 / Gr cell at 45 °C during cycling at a 0.5C rate. The capacity retention of the EE101 cell was comparable to that of the CE101 and CE102 cells, with approximately 75% retention after 600 cycles. The cells subjected to the high temperature storage test were charged to 4.2 V to 100% state of charge and placed in an environmental chamber set at 60°C. The cells were measured for AC-IR, thickness, and capacity recovery every two weeks. A summary of the results is shown in Table I. As can be seen in Table I, all cells exhibited an increase in internal resistance, some expansion due to gassing, and capacity loss. However, example EE101 exhibited the lowest increase in AC-IR and a significantly lower increase in cell thickness than CE101. CE102 exhibited a lower increase in AC-IR, but the EE101 cell had a lower thickness after 10 weeks of storage.

[0063] Table I: Storage data for 5.0 Ah NMC811 / Gr cells including CE101, CE102, and EE101 TIFF0007761285000019.tif46160

[0064] While various embodiments have been shown and described in detail herein, it will be apparent to those skilled in the art that various modifications, additions, substitutions, etc. may be made without departing from the spirit of the disclosure, and therefore are deemed to be within the scope of the disclosure as defined in the appended claims. The present invention provides, for example, the following items. (Item 1) Aprotic organic solvent systems; Metal salts; and Formula I, II, III, IV, V or VI:

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Claims

1. Aprotic organic solvent system; metal salts; and Formula II, III, IV, V or VI: 【Chemistry 1】 at least one epoxide-functionalized organic compound additive of During the ceremony, n is an integer ranging from 1 to 8; X is oxygen or sulfur for Formulas III, IV and V; X is sulfur for Formulas II and VI; R1, R2, R3, R4, and R5 are independently halogen, C １ ~C １２ Substituted or unsubstituted alkyl group or C ６ ~C １４ an oxygen or sulfur atom further bonded to the aryl group, C １ ~C １２ Substituted or unsubstituted alkyl group or C ６ ~C １４ is an aryl group; wherein any hydrogen or carbon atom can be unsubstituted or independently substituted with a halogen, alkyl, alkoxy, perfluorinated alkyl, silyl, siloxy, silane, sulfoxide, amido, azo, ether, or thioether group, or combinations thereof; R6 and R7 are Independently, C １ ~C １２ Substituted or unsubstituted alkyl group or C ６ ~C １４ an oxygen or sulfur atom further bonded to the aryl group; Independently C １ ~C １２ Substituted or unsubstituted alkyl group or C ６ ~C １４ aryl group wherein any hydrogen or carbon atom can be unsubstituted or independently substituted with an epoxide, halogen, alkyl, alkoxy, perfluorinated alkyl, silyl, siloxy, silane, sulfoxide, amide, azo, ether, or thioether group, or combinations thereof; and R8, R9, and R10 are independently hydrogen, C １ ~C １２ selected from alkyl, heteroalkyl, perfluoroalkyl, alkenyl, aryl or alkoxy groups; Epoxide-functionalized organic compound additives 1. An electrochemical energy storage device electrolyte comprising:

2. 10. The electrolyte of claim 1, wherein the at least one epoxide-functionalized organic compound additive is present in the electrolyte at a concentration of 0.01% to 10% by weight.

3. 2. The electrolyte of claim 1, wherein the aprotic organic solvent system comprises a linear or cyclic carbonate, a carboxylic acid ester, a nitrite, an ether, a sulfone, a ketone, a lactone, a dioxolane, a glyme, a crown ether, a siloxane, a phosphate ester, a phosphite, a mono- or polyphosphazene, or a mixture thereof.

4. 10. The electrolyte of claim 1, wherein the aprotic organic solvent system is present in the electrolyte at a concentration of 60% to 90% by weight.

5. 2. The electrolyte of claim 1, wherein the cation of the metal salt is an alkali metal.

6. 6. The electrolyte of claim 5, wherein the alkali metal is lithium or sodium.

7. 2. The electrolyte of claim 1, wherein the cation of the metal salt is aluminum or magnesium.

8. 10. The electrolyte of claim 1, wherein the metal salt is present in the electrolyte at a concentration of 10% to 30% by weight.

9. The electrolyte of claim 1 further comprising at least one additional additive.

10. 10. The electrolyte of claim 9, wherein the at least one additional additive comprises a sulfur-containing compound, a phosphorus-containing compound, a boron-containing compound, a silicon-containing compound, a fluorine-containing compound, a nitrogen-containing compound, a compound containing at least one unsaturated carbon-carbon bond, a carboxylic acid anhydride, or a mixture thereof.

11. 10. The electrolyte of claim 9, wherein the at least one additional additive comprises a partially or fully halogenated phosphate ester compound, an ionic liquid, (methylsulfonyl)cyclotriphosphazene, or a mixture thereof.

12. 12. The electrolyte solution of claim 11, wherein the partially or fully halogenated phosphate ester compound is 4-fluorophenyl diphenyl phosphate, 3,5-difluorophenyl diphenyl phosphate, 4-chlorophenyl diphenyl phosphate, trifluorophenyl phosphate, heptafluorobutyl diphenyl phosphate, trifluoroethyl diphenyl phosphate, bis(trifluoroethyl)phenyl phosphate, or phenyl bis(trifluoroethyl)phosphate.

13. The electrolyte solution according to claim 11, wherein the ionic liquid is tris(N-ethyl-N-methylpyrrolidinium)thiophosphate bis(trifluoromethylsulfonyl)imide, tris(N-ethyl-N-methylpyrrolidinium)phosphate bis(trifluoromethylsulfonyl)imide, tris(N-ethyl-N-methylpiperidinium)thiophosphate bis(trifluoromethylsulfonyl)imide, or tris(N-ethyl-N-methylpiperidinium)phosphate bis(trifluoromethylsulfonyl)imide.

14. 10. The electrolyte of claim 9, wherein the at least one additional additive is present in the electrolyte at a concentration of 0.01% to 10% by weight.

15. Positive electrode; Negative electrode; The electrolyte solution of claim 1; and Separator 1. An electrochemical energy storage device comprising:

16. 16. The device of claim 15, wherein the positive electrode comprises lithium metal oxide, spinel, olivine, carbon-coated olivine, vanadium oxide, lithium peroxide, sulfur, polysulfides, lithium carbon monofluoride, or mixtures thereof.

17. The lithium metal oxide is LiCoO ２ , LiNiO ２ , LiNi ｘ Co ｙ Met ｚ O ２ , LiMn ０．５ Ni ０．５ O ２ , LiMn ０．１ Co ０．１ Ni ０．８ O ２ , LiMn ０．２ Co ０．２ Ni ０．６ O ２ , LiMn ０．３ Co ０．２ Ni ０．５ O ２ , LiMn ０．３３ Co ０．３３ Ni ０．３３ O ２ , LiMn ２ O ４ , LiFeO ２ , Li １＋ｘ 'Ni α Mn β Co γ Met' δ O ２－ｚ 'F ｚ ', or A ｎ 'B ２ (XO ４ ) ３ wherein Met is Al, Mg, Ti, B, Ga, Si, Mn, or Co; Met′ is Mg, Zn, Al, Ga, B, Zr, or Ti; A is Li, Ag, Cu, Na, Mn, Fe, Co, Ni, Cu, or Zn; B is Ti, V, Cr, Fe, or Zr; X is P, S, Si, W, or Mo; and wherein 0≦x≦0.3, 0≦y≦0.5, 0≦z≦0.5, 0≦x′≦0.4, 0≦α≦1, 0≦β≦1, 0≦γ≦1, 0≦δ≦0.4, 0≦z′≦0.4 and 17. The device of claim 16, wherein 0≦n′≦3.

18. The negative electrode is made of lithium metal, graphite material, amorphous carbon, Li ４ Ti ５ O １２ 17. The device of claim 16, comprising a tin alloy, silicon, a silicon alloy, an intermetallic compound, or a mixture thereof.

19. Lithium battery, lithium-ion battery, lithium-sulfur battery, lithium-air battery, sodium-ion battery, magnesium battery, lithium / MnO ２ 16. The device of claim 15, comprising a battery or a Li / poly(carbon monofluoride) battery.

20. The device of claim 15 comprising an electrochemical cell.

21. 16. The device of claim 15, wherein the separator comprises a porous separator separating the negative and positive electrodes from each other.

22. 16. The device of claim 15, wherein the porous separator comprises an electron beam treated microporous polyolefin separator or a microporous polymer film comprising nylon, cellulose, nitrocellulose, polysulfone, polyacrylonitrile, polyvinylidene fluoride, polypropylene, polyethylene, polybutene, or a copolymer or mixture of any two or more such polymers.

23. 16. The device of claim 15, wherein the aprotic organic solvent system comprises a linear or cyclic carbonate, a carboxylic acid ester, a nitrite, an ether, a sulfone, a ketone, a lactone, a dioxolane, a glyme, a crown ether, a siloxane, a phosphate ester, a phosphite, a mono- or polyphosphazene, or a mixture thereof.

24. 16. The device of claim 15, wherein the aprotic organic solvent system is present in the electrolyte at a concentration of 60% to 90% by weight.

25. 16. The device of claim 15, wherein the cation of the metal salt is an alkali metal.

26. 26. The device of claim 25, wherein the alkali metal is lithium or sodium.

27. 16. The device of claim 15, wherein the cation of the metal salt is aluminum or magnesium.

28. 16. The device of claim 15, wherein the metal salt is present in the electrolyte at a concentration of 10% to 30% by weight.

29. 16. The device of claim 15, wherein the electrolyte further comprises at least one additional additive.

30. 30. The device of claim 29, wherein the at least one additional additive comprises a sulfur-containing compound, a phosphorus-containing compound, a boron-containing compound, a silicon-containing compound, a fluorine-containing compound, a nitrogen-containing compound, a compound containing at least one unsaturated carbon-carbon bond, a carboxylic acid anhydride, or a mixture thereof.

31. 30. The device of claim 29, wherein the at least one additional additive comprises a partially or fully halogenated phosphate ester compound, an ionic liquid, (methylsulfonyl)cyclotriphosphazene, or a mixture thereof.

32. 32. The device of claim 31, wherein the halogenated phosphate ester compound is 4-fluorophenyl diphenyl phosphate, 3,5-difluorophenyl diphenyl phosphate, 4-chlorophenyl diphenyl phosphate, trifluorophenyl phosphate, heptafluorobutyl diphenyl phosphate, trifluoroethyl diphenyl phosphate, bis(trifluoroethyl)phenyl phosphate, or phenyl bis(trifluoroethyl) phosphate.

33. 32. The device of claim 31 , wherein the ionic liquid is tris(N-ethyl-N-methylpyrrolidinium)thiophosphate bis(trifluoromethylsulfonyl)imide, tris(N-ethyl-N-methylpyrrolidinium)phosphate bis(trifluoromethylsulfonyl)imide, tris(N-ethyl-N-methylpiperidinium)thiophosphate bis(trifluoromethylsulfonyl)imide, tris(N-ethyl-N-methylpiperidinium)phosphate bis(trifluoromethylsulfonyl)imide, N-methyl-trimethylsilylpyrrolidinium bis(trifluoromethylsulfonyl)imide, or N-methyl-trimethylsilylpyrrolidinium hexafluorophosphate.

34. 30. The device of claim 29, wherein the at least one additional additive is present in the electrolyte at a concentration of 0.01% to 10% by weight.

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