Functionalized crown ethers for lithium-ion batteries

Abstract

Disclosed is an electrolyte containing a functionalized crown ether suitable for use in an electrochemical energy storage device, which is useful for reducing battery resistance, increasing cycle life, and improving high-temperature performance. According to one aspect of the present disclosure, a new class of compounds and an electrolyte for an electrochemical energy storage device are provided. The electrolyte comprises a functionalized crown ether; an aprotic organic solvent; and a metal salt. According to another aspect of the present disclosure, an electrolyte for an electrochemical energy storage device is provided, the electrolyte comprising a functionalized crown ether; an aprotic organic solvent; a metal salt; and at least one additive.

Description

[Technical Field]

[0001] cross reference This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 63 / 392,025, filed July 25, 2022, which is incorporated herein by reference in its entirety.

[0002] Field The present disclosure relates to functionalized crown ethers useful for reducing battery resistance, increasing cycle life, and improving high temperature performance; electrolytes containing the functionalized crown ethers; and electrochemical energy storage devices utilizing the electrolytes. [Background technology]

[0003] background Li-ion batteries are widely used in consumer electronics, electric vehicles (EVs), and energy storage systems (ESSs) and smart grids. In recent years, Li-ion batteries with voltages above 4.35 V have become increasingly important due to the benefits of higher capacity and subsequent energy density. However, the stability of cathode materials at these potentials decreases due to increased oxidation. This can result in electrochemical oxidation of the material and gas generation, which can adversely affect battery performance. Cathode active materials capable of lithium ion insertion / extraction can dissolve in non-aqueous electrolytes, resulting in structural decomposition of the material and increased interfacial resistance. These Li-ion batteries are also typically exposed to extreme temperatures during their operation. The SEI (solid-electrolyte interface) layer formed on the anode gradually decomposes at high temperatures, thus leading to more irreversible reactions and capacity loss. Similarly, the CEI (cathode-electrolyte interface) also loses stability at high temperatures. These reactions occur at the positive and negative electrodes during cycling and are generally more intense at higher temperatures due to faster kinetics. Next-generation Li-ion batteries for use in consumer electronics, EVs, and ESSs will require significant improvements in electrolyte composition compared to current state-of-the-art Li-ion batteries.

[0004] The primary function of an electrolyte is the shuttling of cations and anions between battery electrodes. Until now, researchers have focused on developing battery electrodes, limiting electrolyte development. Traditional Li-ion batteries use carbonate-based electrolytes with a large electrochemical window through which lithium ions can be transported. These electrolytes require functional additives to passivate the anode and form a stable SEI, as well as additives to stabilize the cathode. At the same time, there is a need to design and develop additives that enable stable and safe cycling of high-voltage, high-energy Li-ion batteries.

[0005] As the industry moves toward higher energy cathode materials for higher energy batteries, stable, efficient, and safe cycling of the battery over a wide voltage window is essential. Li-ion battery electrolytes can be tailored by the addition of various co-solvents and additives based on their application. This tunability has enabled the development of various additives for high voltage stability and safety of Li-ion cells. The literature has reported on crown ethers capable of coordinating with metal ions as additives, which may have a wide range of beneficial effects, from improving lithium solvation to reducing charge transfer resistance and capturing dissolved manganese ions from the cathode (Ochida, M.; Doi, T.; Domi, Y.; Tsubouchi, S.; Nakagawa, H.; Yamanaka, T.; Abe, T.; Ogumi, Z.J. Electrochem. Soc. 2013, 160, A410; Xu, K. Chem. Rev. 2004, 104, 4303). Japanese Patent JP2000195548A reports the use of crown ethers and azacrown ethers as components of electrolytes for lithium secondary batteries. U.S. Patent No. 9,130,231 reports the use of crown ethers as components of microporous separators for lithium-ion batteries. Chinese patent CN103613576 reports the synthesis of macrocyclic cyclic sulfates. Herein, functionalized crown ethers are reported as additives for Li-ion batteries. These molecules, when added to the electrolyte, enable stabilization of the cathode and holistic electrolyte system. Cells containing this additive in the electrolyte enable safe, high-energy Li-ion batteries with long cycle life. Therefore, there is a need to incorporate these novel additives to improve the performance of Li-ion batteries. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-195548 [Patent Document 2] U.S. Patent No. 9,130,231 [Patent Document 3] Chinese Patent No. 103613576 [Non-patent literature]

[0007] [Non-Patent Document 1] Ochida, M.; Doi, T.; Domi, Y.; Tsubouchi, S.; Nakagawa, H.; Yamanaka, T.; Abe, T.; Ogumi, ZJ Electrochem. Soc. 2013, 160, A410, Xu, K. Chem. Rev. 2004, 104, 4303 Summary of the Invention [Means for solving the problem]

[0008] overview According to one aspect of the present disclosure, a new class of compounds and electrolytes for electrochemical energy storage devices are provided, the electrolytes comprising a functionalized crown ether; an aprotic organic solvent; and a metal salt.

[0009] According to another aspect of the present disclosure, there is provided an electrolyte for an electrochemical energy storage device, the electrolyte comprising: a functionalized crown ether; an aprotic organic solvent; a metal salt; and at least one additive.

[0010] According to another aspect of the present disclosure, there is provided an electrochemical energy storage device comprising: a cathode; an anode; a separator; and an electrolyte comprising a functionalized crown ether, an aprotic organic solvent, and a metal salt.

[0011] According to another aspect of the present disclosure, there is provided an electrolyte for an electrochemical energy storage device, the electrolyte comprising: a functionalized crown ether; an aprotic organic solvent; a metal salt; and at least one additive, wherein the aprotic organic solvent comprises an open-chain or cyclic carbonate, carboxylic acid ester, nitrite, ether, sulfone, sulfoxide, ketone, lactone, dioxolane, glyme, crown ether, siloxane, phosphate ester, phosphite, monophosphazene, or polyphosphazene, or a mixture thereof.

[0012] According to another aspect of the present disclosure, an electrolyte for an electrochemical energy storage device is provided, the electrolyte comprising: a functionalized crown ether; an aprotic organic solvent; a metal salt; and at least one additive, wherein the cation of the metal salt is aluminum, magnesium, or an alkali metal, such as lithium or sodium.

[0013] According to another aspect of the present disclosure, there is provided an electrolyte for an electrochemical energy storage device, the electrolyte comprising: a functionalized crown ether; an aprotic organic solvent; a metal salt; and at least one additive, wherein the 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.

[0014] These and other aspects of the present disclosure will become evident upon review of the following detailed description and claims appended hereto. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 shows the differential capacity profile of the cell formation relative to the dQ / dV profile of the electrolytes tested in the NMC622 / Gr cell.

[0016] [Figure 2] FIG. 2 shows the room temperature cycle life characteristics of the electrolytes tested in the NMC622 / Gr cell in a cycle life plot.

[0017] [Figure 3] Figure 3 shows the differential capacity profile of the cell formation relative to the dQ / dV profile of the electrolytes tested in the NMC811 / SiO+Gr cell.

[0018] [Figure 4] Figure 4 shows the room temperature cycle life characteristics of the electrolytes tested in the NMC811 / SiO+Gr cell in a cycle life plot. DETAILED DESCRIPTION OF THE INVENTION

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

[0020] This disclosure describes a Li-ion battery electrolyte containing an electrolyte formulation that can overcome the cathode stability challenge in Li-ion batteries, particularly those containing high-voltage, high-nickel cathode materials. Current state-of-the-art Li-ion batteries contain cathode materials with low nickel content that operate at high voltages, or high nickel content that operate at low voltages. Current state-of-the-art electrolytes are tuned for 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 electrolyte solutions for the cycling of Li-ion cells containing high-voltage, high-nickel cathodes. This technology is based on an innovative functionalized crown ether that, when incorporated into the electrolyte, can improve the stability of high-voltage, high-energy cathodes. When used at low weight loadings, the electrolyte ether forms a unique cathode-electrolyte interface (CEI) without overpassivating the cathode. Additionally, the improved CEI improves high-temperature performance and storage stability without any room-temperature effects.

[0021] In some embodiments, the electrochemical energy storage device electrolyte comprises: a) an aprotic organic solvent; b) a metal salt; and c) a functionalized crown ether compound material. In some embodiments, the functionalized crown ether compound material is present in a concentration of 0.01 wt % to 10 wt % of the electrolyte.

[0022] In one embodiment of the present disclosure, the molecular structure of at least one functionalized crown ether organic compound according to Formula I, II, or III [ka] [ka] (In the formula, n is an integer ranging from 1 to 8, X is independently oxygen or sulfur; R is independently halogen, C1-C 12 Substituted or unsubstituted alkyl groups, or C6-C 14 an oxygen or sulfur atom further bonded to the aryl group, Any hydrogen atom may be replaced with an epoxide, halogen, alkyl, alkoxy, perfluorinated alkyl, silyl, siloxy, silane, sulfoxide, amide, azo, ether, and thioether group or a combination thereof, and the carbon atoms may be unsubstituted or substituted with an epoxide, halogen, alkyl, alkoxy, perfluorinated alkyl, silyl, siloxy, silane, sulfoxide, amide, azo, ether, and thioether group or a combination thereof.

[0023] Specific examples of molecules according to the present disclosure are listed below. [ka] [ka] [ka] These examples are merely illustrative and are not intended to limit the disclosure of the following claims.

[0024] The addition of functionalized crown ethers to Li-ion battery systems allows for the sequestration of metal ions and stabilization of the cathode surface. This suppresses further oxidative decomposition of the remaining electrolyte components that would otherwise occur upon contact with the cathode material. The inclusion of phosphorus-oxygen bonds can ensure good coordination with high-nickel, high-energy cathode materials.

[0025] The present disclosure also includes methods for synthesizing functionalized crown ethers and the use of such molecules in lithium-ion battery electrolytes, which impart greater stability to the electrolyte and cathodes operating at higher potentials.

[0026] In some aspects of the present disclosure, the electrolyte includes a metal salt. In some embodiments, the metal salt is present in the electrolyte in a range of 10% to 30% by weight. In some embodiments, the cation of the metal salt is aluminum, magnesium, or an alkali metal, such as lithium or sodium. For example, 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 mixtures of any two or more of these, where Z is independently in each occurrence a halogen, j is an integer from 0 to 12, and j' is an integer from 1 to 10.

[0027] In some aspects of the present disclosure, the electrolyte comprises an aprotic organic solvent selected from open-chain or cyclic carbonates, carboxylic acid esters, nitrites, ethers, sulfones, sulfoxides, ketones, lactones, dioxolanes, glymes, crown ethers, siloxanes, phosphate esters, phosphites, monophosphazenes or polyphosphazenes, or mixtures thereof. In some embodiments, the solvent is present in the electrolyte in an amount ranging from 50% to 90% by weight.

[0028] Examples of aprotic solvents for producing electrolytes include 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 ethyl carbonate. Examples of suitable amines include, but are not limited to, fluorinated oligomers, methyl propionate, ethyl propionate, butyl propionate, dimethoxyethane, triglyme, 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 some embodiments of the present disclosure, the electrolyte further comprises at least one additive for protecting the electrodes and the electrolyte from decomposition. Thus, the electrolyte 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.

[0030] In some embodiments, 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 when 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 ... N-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 phosphate, methoxy-o-terphenyl, methyl phosphate, oxetan-2-yl-vinylamine, oxiranyl vinylamine, vinyl carbonate, vinyl crotonate, vinyl cyclopentanone, vinyl ethyl 2-furoate, vinyl ethylene carbonate, vinyl ethylene silicate, vinyl ethylene sulfate, vinyl ethylene sulfite, vinyl methacrylate, vinyl phosphate, vinyl 2-furoate, vinyl cyclopropanone (vinyl, Cylo propanone), vinyl ethylene oxide, β-vinyl-γ-butyrolactone, or a mixture of any two or more of these. In some embodiments, the additive can be a cyclotriphosphazene substituted with F, alkyloxy, alkenyloxy, aryloxy, methoxy, allyloxy groups, sulfonic acid groups, or a combination thereof. For example, the additive can 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 the range of 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. Examples of ionic liquids 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, and N-methyl-trimethylsilylpyrrolidinium hexafluorophosphate. Additionally, additives may be present in the range of 0.01% to 10% by weight.

[0034] 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, for example, 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 some embodiments, a secondary battery is provided that includes a positive electrode and a negative electrode separated from one another using a porous separator, and an electrolyte described herein.

[0036] Suitable cathode materials for secondary batteries containing the electrolytes described herein include vanadium oxide, lithium peroxide, sulfur, polysulfides, lithium carbon monofluoride (LiCF x (also known as SiO2), or a mixture of any two or more of these, carbon coated olivine cathodes, e.g., LiFePO4, lithium metal oxides, e.g., LiCoO2, LiNiO2, LiNi x Co y Met z O2, LiMn 0.5 Ni 0.5 O2, LiMn 0.1 Co 0.1 Ni 0.8 O2, LiMn 0.2 Co 0.2 Ni 0.6 O2, LiMn 0.3 Co 0.2 Ni 0.5 O2, LiMn 0.33 Co 0.33 Ni 0.33 O2, LiMn2O4, LiFeO2, Li 1+x’ Ni α Mn β Co γ Met' δO 2-z’ F z’ , or A n’ Examples of suitable olivine cathodes include, but are not limited to, B2(XO4)3, where 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; and X is P, S, Si, W, or Mo; and 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 0≦n'≦3. In other embodiments, the olivine cathode is 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 0≦x≦0.3, 0≦y≦0.5, 0≦z≦0.5, 0≦m≦0.5, and 0≦n≦0.5.

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

[0038] In some embodiments, the anode is a composite anode containing an active material, such as silicon or a silicon alloy, and a conductive polymer coating around the active material. The active material may be in the form of silicon particles having a particle size between about 1 nm and about 100 μm. Other suitable active materials include, but are not limited to, hard carbon, graphite, tin, and germanium particles. The polymer coating material can be cyclized using a heat treatment at temperatures between 200°C and 400°C, thereby converting the polymer into a ladder compound by crosslinking the polymer chains. Specific polymers that can be used include, but are not limited to, polyacrylonitrile (PAN), in which nitrile bonds (C≡N) are converted to double bonds (C═N) upon cyclization. The polymer material forms an elastic yet robust film, allowing for controlled fragmentation / pulverization of the silicon particles within the polymer matrix. In addition, the PAN matrix also provides a pathway for Li-ion migration, thereby enhancing the conductivity of the composite anode. The resulting anode material can overcome the expansion and conductivity challenges of silicon-based anodes by, for example, including a binder that can prevent silicon particle expansion and a conductive additive that provides a path for Li-ion migration. In some embodiments, the polymer is about 10% to 40% by weight of the anode composite. Further description of these Si-PAN composite anodes is provided in U.S. Pat. Nos. 10,573,884 and 10,707,481, both of which are incorporated herein by reference in their entireties.

[0039] Separators for lithium batteries are often microporous polymer membranes. Examples of polymers for forming the membranes include polypropylene, polyethylene, nylon, cellulose, nitrocellulose, polysulfone, polyacrylonitrile, polyvinylidene fluoride, polybutene, or copolymers or blends of any two or more such polymers. In some cases, the separator is an electron beam-treated microporous polyolefin separator. The electron treatment can increase the separator's deformation temperature and thus enhance its thermal stability at high temperatures. Additionally or alternatively, the separator can be a shutdown separator. A shutdown separator can have a trigger temperature greater than about 130°C, allowing the electrochemical cell to operate at temperatures up to about 130°C.

[0040] The present disclosure is further illustrated with 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 claims that follow. [Example]

[0041] Example A Synthesis of triethylene glycol-thiolane [ka] 1. To a 100 mL 3-neck flask equipped with a magnetic stir bar, water-cooled condenser, N2 inlet, and thermocouple was added triethylene glycol and dichloromethane (DCM) (20 mL). Triethylamine was added via pipette and an exotherm to 24 °C was observed. The mixture was cooled to 0 °C in an ice bath. 2. While stirring at 0°C, thionyl chloride was added slowly dropwise via syringe. A maximum exotherm to 15°C was observed, and a white solid ppt (triethylamine-HCl) rapidly formed. Once the addition was complete, the ice bath was removed. The colorless mixture was allowed to slowly warm to room temperature and stirred for 1 hour. 3. DI water (2 x 20 mL) was added and the mixture was poured into a separatory funnel. The organic phase was extracted into DCM, separated, dried over MgSO4, filtered, and the solvent removed by rotary evaporation to an oil. The oil was pumped under high vacuum. The oil was passed through a 0.45 mm GMF filter and dried in a vacuum oven (5 mbar, 60 °C). Yield: dense, colorless oil, 2.5 g (99%). FTIR:2870, 1198, 873, 698cm -1

[0042] Example B Synthesis of triethylene glycol phenyl phosphate [ka] 1. To a 40 mL vial equipped with a magnetic stir bar and thermocouple was added triethylene glycol and DCM (10 mL). Triethylamine was added via pipette and no exotherm was observed. 2. While stirring at room temperature, phenyl dichlorophosphate was added slowly dropwise via syringe. An exotherm to 42°C was observed and a white solid, ppt (triethylamine-HCl), rapidly formed. The pale yellow mixture was allowed to slowly warm to room temperature and stirred for 1 hour. 3. DI water (2 x 10 mL) was added and the mixture was poured into a separatory funnel. The organic phase was extracted into DCM, separated, washed with 5% HCl (5 mL), separated, dried over MgSO4, and the solvent removed by rotary evaporation to an oil. Crude product yield: dense yellow oil, 1.6 g (>99%). FTIR:3459, 2970, 1735, 1364, 1219, 931, 525cm -1 .

[0043] Example C Electrolyte for NMC622 / Gr cells The electrolyte formulation was prepared by combining all electrolyte components in a glass vial in a dry argon-filled glovebox and stirring for 24 hours to ensure complete dissolution of the salts. A 3:7 by weight mixture of ethylene carbonate "EC" and ethyl methyl carbonate "EMC" and Li + A functionalized crown ether is added to a base electrolyte formulation containing 1 M lithium hexafluorophosphate (LiPF6) dissolved therein as the ionically conductive salt. Conventional additives such as vinylene carbonate (VC) and fluoroethylene carbonate (FEC) are added. Comparative Example 1 (CE1) as shown in Table A. Embodiment Example 1 (EE1) uses a representative example molecule according to the present disclosure. The electrolyte components and additives used are summarized in Table A. [Table A]

[0044] Example D NMC622 / Gr cell electrochemical data The prepared electrolyte formulation was used as the electrolyte in 200 mAh Li-ion pouch cells containing lithium nickel manganese cobalt oxide (NMC622) cathode active material and graphite as the anode active material. 0.9 mL of electrolyte formulation was added to each cell and allowed to soak for 1 hour. The cells were vacuum sealed and subjected to a primary charge of 10 hours at 25°C before wetting. 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, and the results are summarized in Table B. The dQ / dV profile is shown in Figure 1, which demonstrates that the addition of the functionalized crown ether results in a reduction peak at 2.4 V during the initial charge of the cell. This additional reduction peak indicates a change in the resulting SEI. AC-IR is the internal resistance measured at 1 kHz, and the reported discharge capacity refers to the final first discharge at a C / 10 rate. The cells containing the EE1 electrolyte had lower AC-IR values compared to CE1, which is a result of the additive in the electrolyte. [Table B] The cells were then charged and discharged 200 times between 4.45 and 3.0 V at a 0.5 C rate at 25 °C. As can be seen in Figure 2, the discharge capacity retention of the cells containing EE1 electrolyte was comparable to that of the cells containing CE1, indicating that the functionalized crown ether additive can perform similarly to conventional commercial additive blends. The capacity retention values are summarized in Table C. [Table C]

[0045] Example E Electrolyte for NMC811 / SiO+Gr cells The electrolyte formulations were prepared in a dry, argon-filled glovebox by combining all electrolyte components in a glass vial and stirring for 24 hours to ensure a completely homogeneous mixture. The individual components of the electrolyte formulation were EC, EMC, FEC, 1,3-propane sultone (PaS), ethylene sulfate (ESA), LiPF, lithium difluorophosphate (LFO), lithium bis(oxalato)borate (LiBOB), and 1,3,6,9-tetraoxa-2-thiacycloundecane-2,2-dioxide (EFCE). The base formulation for all tested formulations was 1 M LiPF in EC / EMC (30 / 70 by weight) solvent, containing 1.0 wt% LFO, 1 wt% LiBOB, 5 wt% FEC, 0.5 wt% PaS, and 0.5 wt% ESA. The example embodiment uses EFCE, a representative molecule according to the present disclosure, at a concentration of 1.0 weight percent and is readily miscible in solution. The electrolyte components and additives used are summarized in Table D. [Table D]

[0046] Example F NMC811 / SiO+Gr cell electrochemical data The prepared electrolyte formulation was used as the electrolyte in 900 mAh Li-ion pouch cells containing lithium nickel manganese cobalt oxide (NMC811) cathode active material and graphite (combined with silicon dioxide in a 9:1 ratio) as the anode active material. To each cell, 2.5 mL of electrolyte formulation was added and allowed to soak for 1 hour. The cells were vacuum sealed and subjected to a primary charge at 25 °C for 24 hours before wetting. The cells were then charged to 4.2 V at a C / 10 rate and discharged to 2.7 V at a C / 10 rate, after which they were degassed and subsequently vacuum sealed. After degassing, the cells were charged and discharged twice between 4.2 and 2.7 V at a C / 10 rate, and the results are summarized in Table E. The dQ / dV profile is shown in Figure 3, which demonstrates that the addition of the functionalized crown ether results in a reduction shoulder at 2.8 V during the initial charge of the cell. This additional reduction peak indicates a change in the SEI that occurs. AC-IR is the internal resistance measured at 1 kHz, and the reported discharge capacity is for the final first discharge at a C / 10 rate. The direct current internal resistance (DCIR) was then collected by applying a 10-second 1 C discharge pulse to the cell and measuring the cell voltage drop. Cells containing EE2 electrolyte had lower AC-IR and DCIR values compared to CE2, which is a result of the functionalized crown in the electrolyte. [Table E]

[0047] The cells were then charged and discharged 200 times between 4.2 and 2.7 V at a 1.0 C rate at 25 °C. As can be seen in Figure 4, the discharge capacity retention of the cells containing EE2 electrolyte was comparable to that of the cells containing CE2, indicating that the functionalized crown ether additive can perform similarly to conventional commercial additive blends. The capacity retention values are summarized in Table F. [Table F]

[0048] 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, and the like may be made without departing from the spirit of the disclosure and are therefore considered to be within the scope of the present disclosure as defined in the claims that follow.

Claims

1. an aprotic organic solvent; a metal salt; and at least one compound according to Formula I, II, or III, 【Chemistry 8】 During the ceremony, n is an integer ranging from 2 to 8; X is independently oxygen or sulfur; R is independently halogen, C １ ~C １２ a 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 a substituted or unsubstituted alkyl group, or C ６ ~C １４ is an aryl group, Any hydrogen atom may be replaced with an epoxide, halogen, alkyl, alkoxy, perfluorinated alkyl, silyl, siloxy, silane, sulfoxide, amide, azo, ether, and thioether group or a combination thereof, and the carbon atoms may be unsubstituted or substituted with an epoxide, halogen, alkyl, alkoxy, perfluorinated alkyl, silyl, siloxy, silane, sulfoxide, amide, azo, ether, and thioether group or a combination thereof; Electrochemical energy storage device electrolyte.

2. The at least one compound according to Formula I, II, or III has the following structure: 【Chemistry 9】 10. The electrolyte of claim 1, wherein

3. 10. The electrolyte of claim 1, wherein the at least one compound according to Formula I, II, or III is present in a concentration of 0.01% to 10% by weight of the electrolyte.

4. 2. The electrolyte of claim 1, wherein the aprotic organic solvent comprises an open-chain or cyclic carbonate, carboxylic acid ester, nitrite, ether, sulfone, ketone, lactone, dioxolane, glyme, crown ether, siloxane, phosphate ester, phosphite, monophosphazene or polyphosphazene, or mixtures thereof.

5. 2. The electrolyte of claim 1, wherein the aprotic organic solvent is present in a concentration of 50% to 90% by weight of the electrolyte.

6. 10. The electrolyte of claim 1, wherein the cation of the metal salt is an alkali metal.

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

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 additive.

10. 10. The electrolyte of claim 9, wherein the at least one 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, an epoxide, or a mixture thereof.

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

12. a cathode; an anode; The electrolyte of claim 1; Separator and 1. An electrochemical energy storage device comprising:

13. 13. The device of claim 12, wherein the cathode comprises lithium metal oxide, spinel, olivine, carbon-coated olivine, vanadium oxide, lithium peroxide, sulfur, lithium polysulfide, lithium carbon monofluoride, or a mixture thereof.

14. 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 14. The device of claim 13, 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 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 0≦h′≦3.

15. The anode may be made of lithium metal, graphite material, amorphous carbon, Li ４ Ti ５ O １２ 13. The device of claim 12, comprising a tin alloy, silicon, a silicon alloy, an intermetallic compound, or a mixture thereof.

16. 16. The device of claim 15, wherein the anode is a composite anode comprising silicon or a silicon alloy as an active material and a conductive polymer coating around the active material.

17. 17. The device of claim 16, wherein the conductive polymer is polyacrylonitrile (PAN).

18. The device of claim 12 , wherein the separator comprises a porous separator separating the anode and the cathode from each other.

19. 20. The device of claim 18, wherein the porous separator comprises an electron beam treated microporous polyolefin separator or a microporous polymer membrane comprising nylon, cellulose, nitrocellulose, polysulfone, polyacrylonitrile, polyvinylidene fluoride, polypropylene, polyethylene, polybutene, or a copolymer or blend of any two or more such polymers.

20. 13. The device of claim 12, wherein the aprotic organic solvent comprises an open-chain or cyclic carbonate, carboxylic acid ester, nitrite, ether, sulfone, ketone, lactone, dioxolane, glyme, crown ether, siloxane, phosphate ester, phosphite, monophosphazene or polyphosphazene, or mixtures thereof.

21. The device of claim 12, wherein the aprotic organic solvent is present in the electrolyte at a concentration of 50% to 90% by weight.

22. The device of claim 12 wherein the cation of the metal salt is an alkali metal.

23. 23. The device of claim 22, wherein the alkali metal is lithium or sodium.

24. The device of claim 12, wherein the metal salt is present in the electrolyte at a concentration of 10% to 30% by weight.

25. The device of claim 12 , wherein the electrolyte further comprises at least one additive.

26. 26. The device of claim 25, wherein the at least one 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, an epoxide, or a mixture thereof.

27. 26. The device of claim 25, wherein the at least one additive is present in the electrolyte at a concentration of 0.01% to 10% by weight.

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