HK40004607A - Nitrile-substituted silanes and electrolyte compositions and electrochemical devices containing them - Google Patents

Description

Nitrile-substituted silanes and electrolyte compositions and electrochemical devices containing the same

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application with application number 201480003489.6. The application date of the mother case is 6 months and 4 days 2014; the invention provides nitrile-substituted silanes and electrolyte compositions and electrochemical devices comprising the same. Priority of provisional application serial No. 61/830,851 filed on 6/4/2013, incorporated herein by reference.

Technical Field

The present application relates to nitrile-substituted silanes and electrolyte compositions and electrochemical devices comprising the same.

Background

The liquid electrolyte in Li-ion batteries is typically comprised of Ethylene Carbonate (EC) and one or more co-solvents such as dimethyl carbonate (DMC),Lithium salt in organic solvent blends of diethyl carbonate (DEC) or Ethyl Methyl Carbonate (EMC), typically LiPF₆. Unfortunately, LiPF₆Are unstable in these carbonate solvents above 60 ℃ and at charging voltages above 4.3 volts. Operation of Li-ion batteries above these temperatures or voltages results in rapid degradation of the electrode materials and battery performance. Furthermore, current Li-ion electrolyte solvents exhibit a flash point of about 35 ℃ and are a major source of energy released during extreme Li-ion battery failures. In view of these important limitations, current electrolytes are impeding the development of advanced Li-ion batteries for use in all applications, including portable products, electric vehicles (EDVs) and utility scales. The dramatic reduction in battery failure rates also requires large Li-ion batteries to effectively serve applications in EDVs and grid storage.

Thus, there is a long-felt and unmet need for improved electrolyte solutions in energy storage devices, such as Li-ion batteries.

Disclosure of Invention

Disclosed herein are Organosilicon (OS) compounds useful as electrolyte solvents in electrochemical devices and other applications.

Generally, OS compounds are environmentally friendly, nonflammable, high temperature resistant materials. These characteristics make OS materials well suited for use as electrolyte solvents, adhesives, and coatings in energy storage devices. The OS-based electrolyte is compatible with all lithium (Li) based electrochemical systems including primary and rechargeable batteries (i.e., Li-ion, Li-air) and capacitors (i.e., super/ultra-capacitors). The approach to designing OS-based electrolytes into Li batteries includes limited changes in battery design, and these electrolytes can be incorporated into production runs with existing manufacturing processes and equipment.

The OS compounds described herein can be used as liquid electrolyte solvents that replace carbonate-based solvent systems in conventional Li-ion batteries. OS-based solvents provide significant improvements in the performance and abuse resistance of Li-ion batteries, including increased thermal stability for longer life at high temperatures, increased electrolyte flash point for improved safety, increased voltage stability to allow the use of high voltage cathode materials and achieve higher energy densities, reduced battery failure rates consistent with the demand for large Li batteries for EDV and grid storage applications, and compatibility with materials currently used in Li-ion batteries that are readily adopted in current designs. Electric Double Layer Capacitor (EDLC) devices have also demonstrated the functionality of OS-based electrolytes. The OS compounds described herein can be used in OS-based electrolyte blends to meet the needs of particular applications in industrial, military, and consumer product devices.

The objects and advantages of the compounds and electrolyte formulations will appear more fully from the detailed description and drawings that follow.

Disclosed herein are compounds of formula I or formula II:

formula I

Formula II

Wherein R is¹、R²And R³Are identical or different and are independently selected from C₁-C₆Linear or branched alkyl and halogen;

"spacer" is absent or selected from C₁-C₆Linear or branched alkylene, alkenylene or alkynylene, provided that when "spacer" is absent, Y is present;

y is absent or selected from- (O-CH)₂-CH₂)_n-and

，

wherein each subscript "n" is the same or different and is an integer of from 1 to 15, and subscript "x" is an integer of from 1 to 15; and

each R⁴Are the same or different and are selected from the group consisting of cyano (-CN), cyanate (-OCN), isocyanate (-NCO), thiocyanate (-SCN) and isothiocyanate (-NCS).

Also specifically disclosed herein are compounds of formula I wherein a "spacer" is present, and Y is- (O-CH)₂-CH₂)_n-. Additionally, specifically disclosed herein are compounds wherein a "spacer" is present and Y is

。

Additionally, disclosed herein are those wherein "spacer" is absent, and Y is- (O-CH)₂-CH₂)_n-a compound of (a).

Also disclosed herein are compounds having a structure as shown in any one of formulas II, III, IV, and V:

in the formula II, the compound is shown in the specification,

in the formula (III), the compound is shown in the formula,

formula IV

And

the compound of the formula V is shown in the specification,

wherein R is¹、R²And R³Are identical or different and are independently selected from C₁-C₆Linear or branched alkyl and halogen; the "spacer" being C₁-C₆Linear or branched alkylene, alkenylene, or alkynylene; each R⁴Are the same or different and are selected from cyano (-CN), cyanate (-OCN), isocyanate (-NCO), thiocyanate (-SCN) and isothiocyanate (-NCS); each subscript "n" is the same or different and is an integer of from 1 to 15; "x" is an integer from 1 to 15. Also included herein are electrolyte compositions comprising one or more compounds of formula I, II, III, IV, V in combination with a salt, preferably a lithium-containing salt, as described herein.

R¹、R²And R³Can be optionally selected from C₁-C₃Alkyl, chloro and fluoro; and R⁴And optionally cyano.

When the compound comprises formula II, R¹And R³Can be optionally selected from C₁-C₃Alkyl (or simply methyl), chloro and fluoro. Each "n" is optionally and independently an integer from 1 to 5. R⁴And optionally cyano.

When the compound comprises formula III, R¹、R²And R³Can be optionally selected from C₁-C₃Alkyl, chloro and fluoro. In some forms of the compound of formula II, R¹、R²And R³At least one of (a) is halogen; in other forms of the compound of formula II, R¹、R²And R³Is halogen. The "spacer" can optionally be C₂-C₄Linear or branched alkylene. R⁴And optionally cyano.

When the compound comprises formula IV, R¹、R²And R³Can be optionally selected from C₁-C₃Alkyl, chloro and fluoro. In some forms of the compound of formula II, R¹、R²And R³At least one of (a) is halogen; in other forms of the compound of formula II, R¹、R²And R³Is halogen. The "spacer" can optionally be C₂-C₄Linear or branched alkylene. R⁴And optionally cyano. In certain forms of the compounds of formula II, "x" may optionally be 1 to 4.

When the compound comprises formula V, R¹、R²And R³Can be optionally selected from C₁-C₃Alkyl, chloro and fluoro. In some forms of the compound of formula II, R¹、R²And R³At least one of (a) is halogen; in other forms of the compound of formula II, R¹、R²And R³Is halogen. The "spacer" can optionally be C₂-C₄Linear or branched alkylene. R⁴And optionally cyano. In certain forms of the compounds of formula II, "x" may optionally be 1 to 4.

In all forms of the compounds, "halogen" includes fluorine, chlorine, bromine and iodine. Fluorine and chlorine are preferred halogen substituents. The term "lithium salt-containing" specifically includes, but is not limited to, LiClO₄、LiBF₄、LiAsF₆、LiPF₆、LiCF₃SO₃、Li(CF₃SO₂)₂N、Li(CF₃SO₂)₃C、LiN(SO₂C₂F₅)₂Lithium alkyl fluorophosphates and lithium bis (chelated) borate.

Also disclosed herein are electrolyte compositions comprising one or more organosilicon compounds as described in the preceding paragraphs. Also disclosed herein are electrochemical devices comprising such electrolyte compositions. The compounds disclosed herein are very useful for formulating electrolytes for all kinds of charge-storage devices, such as batteries (cells), batteries (batteries), capacitors, and the like.

Drawings

FIG. 1A depicts a LiPF-containing formulation₆、LiBF₄Or F1S of LiTFSI₃MN at Current Density (mA/cm)²) Comparative Voltage (V vs. Li/Li)⁺) Oxidation stability in (1). FIG. 1B depicts an enlarged view of the same data shown in FIG. 1A.

Fig. 2A and 2B depict runs in duplicate to determine with LiPF₆、LiBF₄Or F1S of LiTFSI₃MN at Current Density (mA/cm)²) Comparative voltage (V vs. Li/Li)⁺) Reduction stability in (1).

FIG. 3A depicts a 1M-containing LiPF₆F1S₃MN or F1S₃M2 at Current Density (mA/cm)²) Comparative voltage (V vs. Li/Li)⁺) Oxidation stability in (1). Fig. 3B depicts an enlarged view of the same data shown in fig. 3A.

FIG. 4 depicts a 1M-containing LiPF₆F1S₃MN or F1S₃M2 at Current Density (mA/cm)²) Comparative voltage (V vs. Li/Li)⁺) Reduction stability in (1).

FIGS. 5A and 5B depict LiPF-containing formulations₆F1S₃Thermal stability of MN. Fig. 5A depicts an enlarged view of the same data shown in fig. 5B.

FIG. 6 depicts a LiPF containing formulation₆F1S₃Thermal stability of M2.

FIG. 7 depicts F1S containing LiTFSI₃Thermal stability of MN.

FIG. 8 depicts LiBF containing₄F1S₃Thermal stability of MN.

FIG. 9 depicts pure F1S₃Thermal stability of MN.

FIG. 10 depicts DF1S with 20% EC and VC/LiBOB₃Thermal stability of MN.

Figure 11 depicts the improved stability of F1S3MN electrolyte compared to a carbonate control electrolyte heated with a delithiated NCA cathode.

Fig. 12 depicts the discharge capacity at 30 ℃ at various discharge rates (C-rates) of batteries containing various electrolyte solvents.

Fig. 13 depicts the structure of the test cell.

Fig. 14 depicts the discharge capacity at 55 c at various discharge rates of a battery containing the same electrolyte solvent shown in fig. 12.

Fig. 15 depicts the structure of an EDLC device.

Fig. 16 depicts the performance of EDLC devices comprising DF1S2MN electrolyte containing TEA-BF 4.

Fig. 17 depicts the performance of EDLC devices containing various electrolyte solvents containing TBP-PF 6.

FIG. 18 depicts 1M LiPF containing₆Or 1ND1N at current density (mA/cm) of 1M Litfsi²) Comparative Voltage (V vs. Li/Li)⁺) Oxidation stability in (1).

FIG. 19 depicts 1M LiPF containing₆Or 1ND1N at current density (mA/cm) of 1M Litfsi²) Comparative Voltage (V vs. Li/Li)⁺) Stability of reduction in

FIGS. 20A and 20B depict the use of 1ND1N and 1M LiPF₆Or current density (mA/cm) cyclically scanned from 0-6V and from 6-0V by 1M LiTFSI²) Comparative voltage (V vs. Li/Li)⁺). Fig. 20A depicts the first cycle. Fig. 20B depicts the second cycle.

FIG. 21A depicts a 1M-containing LiPF₆F1S₃MN or 1ND1N at Current Density (mA/cm)²) Comparative voltage (V vs. Li/Li)⁺) Oxidation stability in (1). Fig. 21B depicts an enlarged view of the same data shown in fig. 21A.

FIG. 22A depicts F1S containing 1M LiTFSI₃MN or 1ND1N at Current Density (mA/cm)²) Comparative Voltage (V vs. Li/Li)⁺) Oxidation stability in (1). Fig. 22B depicts an enlarged view of the same data shown in fig. 22A.

FIG. 23 is a mass spectrum illustrating the thermal stability of pure 1ND 1N.

FIG. 24 is a diagram illustrating a LiPF-containing compound₆Thermal stability mass spectrum of 1ND 1N.

FIG. 25A depicts an expanded view of the mass spectral curve described with respect to FIG. 24 from 24-30 m/z. FIG. 25B depicts an enlarged view of the mass spectral curve from 49-55 m/z described with respect to FIG. 24.

FIG. 26 depicts the thermal stability of 1ND1N containing LiTFSI, Vinylene Carbonate (VC), and lithium bis (oxalato) borate (LiBOB).

FIG. 27 depicts LiBF containing₄Thermal stability of 1ND 1N.

Fig. 28 depicts the discharge capacity of batteries containing various electrolytes at various discharge rates.

Fig. 29 depicts a comparison of the discharge capacity of the first cycle and the 50 th cycle for cells containing various other electrolyte solvents.

FIG. 30A depicts a composition containing 1ND1N-LiPF₆-discharge capacity of the electrolyte-based cell at various discharge rates. Fig. 30B depicts the discharge capacity at various discharge rates of a cell containing 1ND 1N-LiTFSI-based electrolyte.

FIG. 31 is a graph of 1ND1N with peak assignment¹H-NMR spectra (in CDCl)₃In (1).

FIG. 32 is F1S with peak assignment₃Of MN¹H-NMR spectra (in CDCl)₃In (1).

FIG. 33 is DF1S with peak assignment₂Of MN¹H-NMR spectra (in CDCl)₃In (1).

FIG. 34 is DF1S with peak assignment₃Of MN¹H-NMR spectra (in CDCl)₃In (1).

FIG. 35 is F1S with peak assignment₃cMN of¹H-NMR spectra (in CDCl)₃In (1).

FIG. 36 is 1S with peak assignment₃Of MN¹H-NMR spectra (in CDCl)₃In (1).

Detailed Description

Throughout the specification, several shorthand abbreviations will be used in order to more easily designate the various organosilicon compounds. The following convention was used:

nNDnthe N compound has the general formula:

wherein R is¹And R³Are identical or different and are independently selected from C₁-C₆Alkyl radical, each R²Are the same or different and are independently selected from the group consisting of cyano (-CN), cyanate (-OCN), isocyanate (-NCO), thiocyanate (-SCN) and isothiocyanate (-NCS), and the two subscripts "n" are the same or different integers and are independently in the range of from 1 to 15. Thus, for example, 1ND1N is where R¹And R³Is methyl (i.e., C)₁) And compounds in which both subscripts "n" are 1.

FnSnThe MN compound has the general formula:

wherein R is¹、R²And R³Are identical or different and are independently selected from C₁-C₆Alkyl (preferably methyl) and halogen (preferably F), "spacer" is C1-C6 linear orBranched divalent hydrocarbon groups (i.e., alkylene, alkenylene, alkynylene), and R⁴Selected from cyano (-CN), cyanate (-OCN), isocyanate (-NCO), thiocyanate (-SCN) and isothiocyanate (-NCS). Is called SnThe compounds of MN have the same structure, wherein R¹、R²And R³Are identical or different and are independently selected from C₁-C₆Alkyl (preferably methyl).

Related compounds disclosed herein have the following structure:

and

wherein R is¹、R²And R³Are identical or different and are independently selected from C₁-C₆Alkyl (preferably methyl) and halogen (preferably F), "spacer" is a C1-C6 linear or branched divalent hydrocarbon radical (i.e., alkylene, alkenylene, alkynylene), R⁴Selected from the group consisting of cyano (-CN), cyanate (-OCN), isocyanate (-NCO), thiocyanate (-SCN) and isothiocyanate (-NCS), and "x" is an integer of from 1 to 15, preferably from 1 to 4.

The compounds disclosed herein can be made by several different routes. The general methods that can be used to prepare the compounds are listed below:

each R group is as defined herein; "n" is a positive integer.

The compounds disclosed herein can also be prepared via the following route:

the compounds disclosed herein are also prepared by several specific routes, including the following reaction schemes:

and

and

and

and

and

and

(R⁴as defined above) and

。

LiTFSI is a commercial product supplied by several international suppliers:

。

the elements and method steps described herein may be used in any combination whether or not explicitly described.

All combinations of method steps as used herein may be performed in any order unless otherwise indicated or clearly implied to the contrary by the context in which the combination is referred to.

As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

As used herein, a range of values is intended to include each and every value and subset of values subsumed within that range, whether or not specifically disclosed. Furthermore, these numerical ranges should be construed as providing support for a claim directed to any number and subset of numbers within the range. For example, disclosure from 1-10 should be considered to support a range from 2-8, from 3-7, from 5-6, from 1-9, from 3.6-4.6, from 3.5-9.9, and so forth.

All patents, patent publications, and publications by peer review (i.e., "references") cited herein are expressly incorporated by reference to the same extent as if each individual reference were specifically and individually indicated to be incorporated by reference. In the event of conflict between the present disclosure and a cited reference, the present disclosure controls.

It is to be understood that the compounds and compositions disclosed herein are not limited to the particular constructions and arrangements of parts illustrated and described herein, but include such modifications as fall within the scope of the claims.

The compounds disclosed herein are organosilicon compounds having shared structural features in the form of one or more terminal substituents that contain carbon-nitrogen double or triple bonds, such as cyano (R-C ≡ N), cyanate (R-O-C ≡ N), isocyanate (R-N = C = O), thiocyanate (R-S-C ≡ N), and/or isothiocyanate (R-N = C = S). Included among the preferred compounds are the following structures:

the above structures are all described with a terminal cyano group. This is for simplicity only. Similar compounds having terminal cyanate, isocyanate, or thiocyanate moieties in place of cyano moieties are expressly within the scope of the present disclosure. Likewise, halogenated compounds are described above as fluorinated compounds. Analogous compounds with other halogen substituents (chlorine, bromine and/or iodine) instead of fluorine atomsWithin the scope of the present disclosure. For each compound listed, two alternative system designations are provided (the first designating the primary core as nitrile and the second designating the primary core as silane for each pair of designations). Additionally, each compound has been given an abbreviated name, where DF = difluoro, TF = trifluoro, and "Sn"referred to as the alkylene spacer between the silicon atom and the terminal cyanate, isocyanate or thiocyanate moiety and" n "represents the number of carbon atoms in the spacer. The physical properties of the selected silicone (OS) compounds are listed in table 1.

As shown in table 1, with the addition of fluorine and the reduction of spacer length, the viscosity decreased, the conductivity increased and the flash point became lower. DF1S₂MN has the lowest viscosity and the highest conductivity.

TABLE 1 physical Properties (20% EC, additive, 1M LiPF)₆)

Pure 1ND2, 1ND1, 1ND1N and F1S₃The physical properties of MN, and of electrolyte solutions containing these solvents, are shown in table 2:

table 2: physical characteristics of solvent and electrolyte

In addition to the organosilicon compounds disclosed herein, the electrolyte compositions of the present invention may also include conventional non-silicon co-solvents. For example, the electrolyte composition of the present invention may include a nitrile and a carbonate ester, such as acetonitrile, Ethylene Carbonate (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC), or Ethyl Methyl Carbonate (EMC). The electrolyte compositions of the present invention may include non-silicon co-solvents in a wide range of concentrations, including, but not limited to, about 1 wt% to about 40 wt%. Examples of suitable co-solvent concentrations include about 1 wt%, about 5 wt%, about 10 wt%, about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 40 wt%, or ranges between and including any of the foregoing amounts.

Examples

F1S₃MN synthesis:

scheme 1 description F1S₃And (5) synthesizing MN. [ F ]]Indicating fluorinating agents, e.g. HF, NH₄FHF or other fluorinating agents. NH (NH)₄FHF is preferably used as fluorinating agent for laboratory scale synthesis. If HF is used, the only by-product is HCl. Synthetic F1S₃The MN compound was washed from the solid salt with hexane, distilled, dried with CaO, and distilled again.

Scheme 2 describes the use of NH₄FHF as fluorinating agent for synthesizing F1S₃And (5) MN flow. Using Karstedt's catalyst (platinum (0) -1, 3-divinyl-1, 1,3, 3-tetramethyldisiloxane Complex solution, product classification No. 479519, Sigma-Aldrich, St. Louis, Mo.), approximately 3% substitution occurred on the second carbon to yield iso F1S₃And (5) MN. Iso F1S₃MN has a ratio of F1S₃MN has a lower boiling point and a large portion thereof can be separated by fractional distillation.

Scheme 3 depicts the use of Cl1S₃Alternative Synthesis of MN intermediate F1S₃Shorter flows for the MN. Cl1S₃MN intermediate is available from Gelest, Inc. (product code SIC2452.0, 11 East Steel Road, Morrisville, PA). Using Cl1S₃The MN intermediate reduces the time spent during synthesis.

Scheme 4 also describes another synthesis of F1S₃And (5) MN flow. As shown in scheme 1, [ F ]]Denotes fluorinating agents, e.g. HF, NH₄FHF or other fluorinating agents. The use of HF as a fluorinating agent in this synthetic scheme will not produce solid by-products, so hexane extraction and filtration of the solid are not required. The only by-product is HCl.

Scheme 5 depicts yet another synthesis F1S₃And (5) MN flow. As shown in scheme 1, [ F ]]Denotes fluorinating agents, e.g. HF, NH₄FHF or other fluorinating agents.

F1S₃And (3) synthesis of MN:

in a preferred route, allyl cyanide is heated to about 100 ℃ with a small amount of Karstedt's catalyst. Dimethylchlorosilane was added dropwise and refluxed for 4 hours. After cooling to room temperature, the mixture was fluorinated at room temperature using 1 mol equivalent of ammonium bifluoride. Cold hexane was added to the mixture, the solid was filtered off and the solvent was evaporated. Calcium oxide was added to the crude product and distilled at 45-55 deg.C under vacuum of 0.4 torr to afford the desired product F1S₃MN。

Determination of electrochemical stability of the organosilicon materials:

computational chemistry methods are used to calculate the electrochemical properties of various organosilicon molecules. The inventors used the GAMESS program developed by the Gordon research group at Iowa State University for molecular orbital calculations (Density Function principles (DFT) molecular orbital calculations) of Density Function Theory (DFT) at Iowa State University. HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energy levels, which correlate with the reduction and oxidation potentials of the compounds, calculated as B3LYP/DZV levels.

The oxidative stability of electrolytes containing organosilicon solvents was determined in a 3-electrode cell using Linear Sweep Voltammetry (LSV) or Cyclic Voltammetry (CV). The platinum microelectrode was used as the working electrode and lithium metal as both the counter and reference electrodes. The potential of the system increased from Open Circuit Voltage (OCV) to 6 or 8V (vs. Li/Li +) at a sweep rate of 10 mV/s. The resulting current density (mA/cm) was recorded at each potential²) A larger current indicates an oxidation reaction (i.e., lower oxidation stability). For linear sweep voltammetry, 8V was used as the final potential to evaluate the basic oxidative stability of the material over a wide voltage range. For cyclic voltammetry, the material was evaluated in multiple scans using 6V at potentials more relevant for conventional battery applications. Multiple scans were performed in cyclic voltammetry experiments to determine the reversibility and irreversibility of any reactions observed.

The reduction stability of the electrolyte containing the silicone solvent was determined using Linear Sweep Voltammetry (LSV) in a 3-electrode cell. A glassy carbon electrode is used as the working electrode and lithium metal is used as both the counter and reference electrodes. The potential of the system decreases from an open circuit voltage (OCV, typically 3V) to 0.1V (vs. Li/Li +) at a sweep rate of 10 mV/s. The resulting current density (mA/cm) was recorded at each potential²) A larger current indicates a reduction reaction (i.e., lower reduction stability). Two scans were performed to assess whether the reductive process was reversible or irreversible (i.e., passivation).

F1S₃Electrochemical stability of MN:

F1S₃MN and F1S₃The molecular orbital diagram (not shown) of M2 revealed that the energy difference between the Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO) for F1S₃MN (9.07 eV) ratio for F1S₃M2 (8.20 eV) is larger. F1S₃MN also has a ratio of F1S₃M2 (-6.84 eV) higher oxidation potential (-8.75 eV).

FIGS. 1A and 1B depict LiPF-containing formulations₆、LiBF₄Or F1S of LiTFSI₃MN at Current Density (mA/cm)²) Contrast voltage (Vvs. Li/Li)⁺) Oxidation stability in (1). At room temperature, a working electrode (Pt), a counter electrode (Li) and a reference electrode (Li/Li) are used⁺) And oxidation stability was tested at a scan rate of 10 mV/s. FIG. 1B depicts an enlarged view of the same data shown in FIG. 1A. F1S₃MN-LiPF₆The electrolyte showed the best oxidation stability with 1 mA/cm at 7.3V²In contrast, for F1S₃MN-LiBF₄And F1S₃MN-LiTFSI is respectively at 1 mA/cm of 6.8V and 6.2V²The current density of (1).

FIGS. 2A and 2B depict LiPF containing formulations₆、LiBF₄Or F1S of LiTFSI₃MN at Current Density (mA/cm)²) Contrast voltage (Vvs. Li/Li)⁺) Reduction stability in (1). At room temperature, a working electrode (Pt), a counter electrode (Li) and a reference electrode (Li/Li) are used⁺) And the reduction stability was tested at a scan rate of 10 mV/s. Fig. 2A and 2B are two independent scans. F1S₃MN-LiPF₆The electrolyte shows the best reduction stability.

FIGS. 3A and 3B depict a 1M-containing LiPF₆F1S₃MN or F1S₃M2 at Current Density (mA/cm)²) Comparative Voltage (V vs. Li/Li)⁺) Oxidation stability in (1). At room temperature, a working electrode (Pt), a counter electrode (Li) and a reference electrode (Li/Li) are used⁺) And oxidation stability was tested at a scan rate of 10 mV/s. Fig. 3B depicts an enlarged view of the same data shown in fig. 3A. F1S₃MN demonstrated relative to F1S₃Improved oxidative stability of M2.

FIG. 4 depicts a 1M-containing LiPF₆F1S₃MN or F1S₃M2 and containing LiPF₆In two separate scans at current density (mA/cm)²) Comparative voltage (V vs. Li/Li)⁺) Reduction stability in (1). At room temperature, a working electrode (Pt), a counter electrode (Li) and a reference electrode (Li/Li) are used⁺) And the reduction stability was tested at a scan rate of 10 mV/s. F1S₃MN authentication with F1S₃M2 compared to less resistance to reduction.

Determination of the thermal stability of the pure solvent & formulated electrolyte:

the thermal stability of both the neat silicone solvent and the electrolyte composition was determined as follows: approximately 0.75 mL of the liquid sample was heated in a sealed cell under an argon purge. An atmospheric sampling mass spectrometer is purged with argon gas, where very low levels of any gas phase impurities and/or decomposition products can be detected using electron impact mass spectrometry (EI-MS). The samples were held at temperature levels (30, 55, 70, 100, 125, 150, 175 and 200 ℃) relevant to battery application for 1 hour prior to assay. The gas phase decomposition products were identified by comparing the fragmentation patterns obtained from EI-MS and NIST standards. After the heating experiment (and detection/collection of all gas phase products), the remaining liquid sample was analyzed via NMR spectroscopy for quantitative analysis of the degree of decomposition. The multiple nuclei were examined to fully analyze all components of the system, including the silicone solvent, any carbonate co-solvent, all additives and lithium salt (if present).

F1S₃Thermal stability of MN:

FIGS. 5A and 5B depict LiPF-containing formulations₆F1S₃Thermal stability of MN. So that F1S₃MN-LiPF₆The electrolyte (batch number ZP815-01) was exposed to temperatures ranging from 30 ℃ to 175 ℃ and analyzed by electron impact mass spectrometry (EI-MS) and nuclear magnetic resonance spectroscopy (NMR) for gaseous and liquid decomposition products, respectively. The temperature at which the hump appears is noted. F1S₃MN showed no significant gas and/or liquid phase decomposition up to 175 ℃. Me₂SiF₂At 10At a temperature of 0-125 ℃ at 81 m/z, and MeSiF₃Occurs at 85 m/z at a temperature of 150 ℃ and 175 ℃. However, the 81 m/z and 85 m/z peaks did not consistently occur at 100-175 ℃. In addition to this, the present invention is,¹h NMR analysis showed no decomposition after heating to 175 ℃. Thus, F1S₃MN did not show consistent decomposition up to 175 ℃. Fig. 5A depicts an enlarged view of the same data shown in fig. 5B.

FIG. 6 depicts a LiPF containing formulation₆F1S₃Thermal stability of M2. So that F1S₃M2-LiPF₆The electrolyte is exposed to temperatures ranging from 30 ℃ to 150 ℃ and the decomposition products are analyzed by mass spectrometry. The temperature at which the hump appears is noted. F1S₃M2 shows decomposition at temperatures ≥ 125 ℃. The decomposition products include Me₂SiF₂And 1, 4-dioxane.¹H NMR analysis showed about 6% decomposition at 150 ℃. These results, in combination with those discussed in relation to fig. 5A and 5B, indicate that F1S₃MN is the ratio F1S₃M2 is more thermally stable.

FIG. 7 depicts F1S containing LiTFSI₃Thermal stability of MN. F1S₃MN-LiTFSI electrolyte was exposed to temperatures ranging from 30 ℃ to 185 ℃ and analyzed by mass spectrometry for decomposition products. The temperature at which the hump appears is noted. The gas phase peak was observed at a temperature of 150 ℃ or higher. Observation of F1S at 117 and 102 matching patterns (matched patterns)₃MN-LiBF₄Peaks of electrolyte and pure solvent (see fig. 8 and 9).

FIG. 8 depicts LiBF containing₄F1S₃Thermal stability of MN. So that F1S₃MN-LiBF₄The electrolyte is exposed to temperatures ranging from 30 ℃ to 200 ℃ and the decomposition products are analyzed by mass spectrometry. The temperature at which the hump appears is noted. The gas phase peak was observed at a temperature of 175 ℃ or higher. Observation of pure solvent and F1S in 117 and 102 matching patterns₃Peaks of MN-LiTFSI electrolyte (see FIGS. 7 and 9).¹H NMR analysis showed no fluorinated decomposition products and<0.5% of non-fluorinated hydrolyzate.

FIG. 9 depicts pure F1S₃Thermal stability of MN. So that F1S₃Exposure of MN electrolyte to ranges from 30 deg.C to 19 deg.CTemperature of 5 ℃ and analysis of the decomposition products by mass spectrometry. The temperature at which the hump appears is noted. The gas phase peak was observed at a temperature of 150 ℃ or higher. Me was observed at 150 ℃₂SiF₂(96/81 m/z), but the other peaks are independent of the product.¹H NMR analysis showed no fluorinated decomposition products and<0.5% hydrolysis.

The above data shows F1S₃MN is the most thermally stable LiPF-containing₆The OS solvent of (2).

DF1S₃And (3) synthesis of MN:

commercial 3-cyanopropyldichloromethylsilane (CAS number 1190-16-5; Sigma Aldrich, St. Louis, MO, US) was fluorinated with ammonium difluoride at room temperature. Cold hexane was then added to the mixture. The solid was filtered off and the solvent was evaporated. Calcium oxide was added to the crude product. The solvent was distilled at a temperature between 35-45 deg.C under a vacuum of 0.4 torr to give the desired product in very high purity (-99.8%) and about 90% yield.

DF1S₂And (3) synthesis of MN:

acrylonitrile was mixed with N, N' -tetramethylethylenediamine and copper (I) oxide in a flask and heated to 60 ℃. Dichloromethylsilane was then added dropwise and refluxed overnight. After cooling to room temperature, the mixture was distilled under vacuum (43 ℃, 0.2 torr) to afford the dichloro intermediate (DCl 1S)₂MN). This intermediate was fluorinated using 1.2 mol equivalents of ammonium bifluoride at room temperature or 1.2 mol equivalents of sodium bifluoride at 130 ℃. Dichloromethane was then added and the solid filtered off. The solvent was evaporated and the crude product was distilled under vacuum. Triethylamine and molecular sieves were added to the product and distilled at 25-33 ℃ under vacuum of 0.1 torr to give very high purity: (>99%) and largeThe desired product is obtained in about 75% yield.

DF1S₃Thermal stability of MN:

FIG. 10 depicts a LiPF containing formulation₆DF1S₃Thermal stability of MN. DF1S₃MN-LiPF₆The electrolyte (ZP990-01) was exposed to temperatures from 30 ℃ to 150 ℃ and analyzed by electron impact mass spectrometry (EI-MS) and nuclear magnetic resonance spectroscopy (NMR) for gas and liquid decomposition products, respectively. DF1S₃MN showed no significant gas and/or liquid phase decomposition up to 150 ℃.

Differential Scanning Calorimetry (DSC) evaluation of resistance to abuse heat:

with F1S in the presence of a delithiated cathode material₃DSC measurements were performed on MN and carbonate-based electrolytes to evaluate the potential effect of resistance to thermal abuse, which may translate into safety advantages in full cell format. Higher starting temperature, lower total heat output, and lower peak heat output are all effective, suggesting improved abuse behavior in full cell format.

FIG. 11 depicts LiPF containing₆And various carbonate co-solvents F1S₃Thermal stability of MN and LiPF containing₆The carbonates of (c) were compared against the electrolyte. The cells containing each electrolyte were charged to 4.25V and then disassembled. The lithium nickel cobalt aluminum oxide (NCA) cathode was rinsed with diethylene carbonate and allowed to dry. Each sample containing 5 mg of active material and 2 mg of fresh electrolyte was sealed in a stainless steel DSC pan. DSC scans at a rate of 2 ℃/min showed that the carbonate control electrolyte reacted at a much lower onset temperature than any silicone electrolyte blend. Additionally, electrolytes in which silicone substituted EMC had much lower peak heat output than the control electrolyte.

Preparing an electrolyte:

the blending of the electrolyte was done in a moisture-free (<5ppm) and oxygen-free (<20ppm) argon glove box. All electrolyte components, including solvents, salts and additives, were completely dried and stored in a glove box prior to mixing. Solvent moisture was monitored periodically by Karl Fischer measurement (Karl Fischer measurement) to ensure that moisture levels were maintained at <20 ppm. Generally, the solvent is first weighed into a separate vial and mixed until homogeneous. 70% of the solvent was added to a volumetric flask. Lithium (or other) salt was added slowly and stirred via a magnetic stir bar until completely dissolved. Any other additives (i.e. VC, LiBOB) are then added slowly and stirred until the solution is homogeneous. The stir bar was removed and a portion of the remaining solvent was added to complete the volumetric metering requirements. The stir bar was placed back in the flask and the electrolyte was stirred until uniform. After mixing is complete, the electrolyte is dispensed into a dry vial or a ready-to-use container for storage.

F1S in lithium ion battery₃Performance of MN

Fig. 12 depicts the discharge capacity at 30 ℃ of batteries containing various electrolyte solvents. 3 different electrolyte solvents were tested in a series of cycles at different discharge rates in a 2032-sized coin cell battery pack (as the pack stack in fig. 13) containing a graphite anode, a lithium nickel cobalt aluminum oxide (NCA) cathode, and a "2500" -type separator plate available from Celgard, LLC (Charlotte, NC). The 3 electrolyte solvents are: (1) control EPA6 carbonate electrolyte (triangles) containing 1:1 volume of Ethylene Carbonate (EC) and diethyl carbonate (DEC); (2) containing 79% of F1S₃MN、20% EC、1 M LiPF₆And Solid Electrolyte Interphase (SEI) -forming additive F1S₃MN-based electrolyte (square); and (3) contains 79% F1S₃M2、20% EC、1 M LiPF₆And SEI-Forming additive F1S₃M2-based electrolyte (circular). As shown in FIG. 12, F1S₃The MN-based electrolyte is equivalent to 4-fold EPA 6.

Fig. 14 depicts the discharge capacity at 55 ℃ of a cell containing the same electrolyte as shown in fig. 12 and described for fig. 12. The cells were assembled in the same manner and cycled at C/2 rate. As shown in FIG. 14, F1S₃MN-BASED SOLVENT AND CARBONATE COMPARATIONS AND F1S₃M2-based electrolyte havingImproved cycling stability at 55 ℃.

In electric double layer capacitor cells F1S₃MN and DF1S₂Performance of MN:

a symmetrical Electric Double Layer Capacitor (EDLC) was assembled into a CR2032 coin cell as depicted in fig. 15. A glass fiber separator (AP40, Merck Millipore) was sandwiched between two AC cloth electrodes with 100 μ L of electrolyte added to the separator. Tetraethylammonium tetrafluoroborate (TEA-BF)₄Alfa Aesar, 99%) and tetrabutylphosphonium hexafluorophosphate (TBP-PF₆Sigma Aldrich,. gtoreq.99.0%) was used as salt. F1S₃MN (99.4%) and DF1S₂MN (99.8%) silicone solvent was prepared from silatron. Acetonitrile (AN, Sigma Aldrich, anhydrous, 99.8%) was used as co-solvent.

Zorflex FM 10100% Activated Carbon (AC) cloth from Calgon Carbon was used for both electrodes. FM10 has a surface area of 1000-2000 m2/g, a thickness of 0.5 mm, and an area density of 120 g/m 2. AC cloth was punched into 15 mm diameter disks and used directly as electrodes without any binder or conductive additive.

The performance of EDLC cells was tested by Cyclic Voltammetry (CV) using a Biologic BMP300 potentiostat. The temperature change controlled in the oven was 0.1 ℃. The Cyclic Voltammetry (CV) response of the EDLC cell was performed between 0 and 3V at a scan rate of 10 mV/s. The normalized specific capacitance (C) is derived from the following equation [1,2 ]:

whereiniIs the flow of electricity, and the temperature of the gas,vis the scan rate and m is the mass of one electrode.

FIG. 16 shows a composition comprising TEA-BF₄Cyclic voltammograms (voltamograms) of EDLC cells with OS electrolyte of salt. Electrolyte ZX1193 comprises DF1S dissolved in 70 vol%₂1.0M TEA-BF of MN and 30 volume percent acetonitrile₄. Electrolyte ZX1190 comprises D dissolved in a mixtureF1S₂0.8MTEA-BF of MN and acetonitrile solvent (60:40 volume ratio)₄. EDLC cells containing both electrolyte formulations showed regular and symmetric features for the 0 horizontal axis, indicating the non-redox or faradaic properties of the cells.

FIG. 17 shows a TBP-containing composition comprising PF₆Cyclic voltammograms of EDLC cells with ZX1170 and ZX1184 electrolytes of salt. Electrolyte ZX1170 has a solvent of F1S₃1.2M TBP-PF in MN₆And electrolyte ZX1184 has a solubility in DF1S₂1.2M TBP-PF in MN₆. Non-redox or faradaic properties can also be observed from EDLC cells containing both electrolyte ZX1170 and ZX1184 formulations.

1ND1N Synthesis:

scheme 6 describes the synthetic scheme for 1ND 1N. 1ND1N can not be replaced by sodium (Na), calcium oxide (CaO) or calcium hydride (CaH)₂) Chemically drying.

Electrochemical stability of 1ND 1N:

for the molecular orbital plots (not shown) of 1ND1N and 1ND1, it was revealed that the energy difference between the Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO) was 7.88eV for 1ND1N (LUMO = 0.21 eV; HOMO = -7.88eV) and 8.36 eV for 1ND1 (LUMO = 1.63 eV; HOMO = -6.73 eV). 1ND1N has greater oxidative stability but lower reduction resistance than 1ND 1.

FIG. 18 depicts 1M LiPF containing₆Or 1ND1N at current density (mA/cm) of 1M Litfsi²) Comparative Voltage (V vs. Li/Li)⁺) Oxidation stability in (1). At room temperature, a working electrode (Pt), a counter electrode (Li) and a reference electrode (Li/Li) are used⁺) And oxidation stability was tested at a scan rate of 10 mV/s.

FIG. 19 depicts 1M LiPF containing₆Or 1ND1N at current density (mA/cm) of 1M Litfsi²) Comparative Voltage (V vs. Li/Li)⁺) Reduction stability in (1). At room temperature, a working electrode (Pt), a counter electrode (Li) and a reference electrode (Li/Li) are used⁺) And the reduction stability was tested at a scan rate of 10 mV/s. Two independent scans of each electrolyte are shown.

FIGS. 20A and 20B depict the use of 1ND1N and 1M LiPF₆Or current density (mA/cm) cyclically scanned from 0-6V and from 6-0V by 1M LiTFSI²) Comparative voltage (V vs. Li/Li)⁺). Fig. 20A depicts the first cycle. Fig. 20B depicts the second cycle.

FIGS. 21A and 21B depict a 1M-containing LiPF₆F1S₃MN or 1ND1N at Current Density (mA/cm)²) Contrast voltage (Vvs. Li/Li)⁺) Oxidation stability of (3). At room temperature, a working electrode (Pt), a counter electrode (Li) and a reference electrode (Li/Li) are used⁺) And oxidation stability was tested at a scan rate of 10 mV/s. Fig. 21B depicts an enlarged view of the same data shown in fig. 21A. F1S₃MN-LiPF₆The electrolyte had a 1 mA/cm voltage at 7.3V²Current density, and 1ND1N-LiPF₆The electrolyte had a 1 mA/cm at 7.2V²The current density.

FIGS. 22A and 22B depict F1S containing 1M LiTFSI₃MN or 1ND1N at Current Density (mA/cm)²) Contrast voltage (Vvs. Li/Li)⁺) Oxidation stability in (1). At room temperature, a working electrode (Pt), a counter electrode (Li) and a reference electrode (Li/Li) are used⁺) And oxidation stability was tested at a scan rate of 10 mV/s. FIG. 22B depicts an enlarged view of the same data shown in FIG. 22A. F1S₃MN-LiTFSI electrolyte has 1 mA/cm at 6.2V²Current density, and 1ND1N-LiTFSI electrolyte has 1 mA/cm at 6.5V²The current density.

Thermal stability of 1ND 1N:

fig. 23 depicts the thermal stability of pure 1ND 1N. 1ND1N was exposed to temperatures ranging from 30 ℃ to 189 ℃ and the decomposition products were analyzed by mass spectrometry. 1ND1N shows no liquid or gas phase decomposition products up to 189 ℃.¹H NMRShows decomposition of 5% to 5%.

FIG. 24 depicts LiPF containing₆Thermal stability of 1ND 1N. 1ND1N-LiPF₆The electrolyte is exposed to temperatures ranging from 30 ℃ to 150 ℃ and the decomposition products are analyzed by mass spectrometry. The temperature at which the hump appears is noted. 1ND1N shows gas phase decomposition ≥ 70 ℃ but no vigorous reaction is observed up to 150 ℃. Me occurs at a temperature of 125-150 DEG C₂SiF₂(81 m/z) (96g/mol) and a peak at 52/53 m/z, which is suspected of being acrylonitrile (53 g/mol). No 1, 4-dioxane gas was observed at 150 ℃.¹H NMR analysis showed 50.6% 1ND1N remaining at 125 ℃ and 58% remaining at 150 ℃. At 125 ℃, the presence of 39.7% of the fluorinated product F1NM1N (comparison 2.3% in the unheated sample), 1.6% Me was observed₂SiF₂(control 0% in the unheated sample), and 2.95% hydrolysis (control 5.5% in the unheated sample). The presence of 41% of the fluorination product F1NM1N (comparison 2.3% in the unheated sample), 1.7% Me was observed at 150 ℃₂SiF₂(control 0% in the unheated sample), and 5.0% hydrolysis (control 5.5% in the unheated sample).

For identification, 1ND1N-LiPF was heated at 125-₆A peak observed at 52/53 m/z, heated 1ND1N-LiPF₆The mass spectral distribution of (A) was compared to the mass spectral distribution of National Institute of Standards and Technology (NIST) standards for 2-acrylonitrile and hydrogen cyanide. FIG. 25A depicts an expanded view of the mass spectral distribution from 24-30 m/z as described with respect to FIG. 24. FIG. 25B depicts an expanded view of the mass spectral distribution from 49-55 m/z with respect to FIG. 24. Note the temperature at which the hump appears in fig. 25A and 25B. The peaks at 51, 52 and 53 m/z in FIG. 25B indicate that acrylonitrile is likely present. The presence of HCN cannot be unequivocally confirmed or denied due to the presence of peaks at 26 and 27 m/z in the NIST spectrum. The spectrum in FIG. 25A shows a greater peak density at 26 m/z compared to 27 m/z, which supports the presence of acrylonitrile. However, the amplitude of the peak at 27 m/z is greater than would be expected for acrylonitrile alone.

FIG. 26 depicts a composition comprising LiTFSI,Thermal stability of 1ND1N of Vinylene Carbonate (VC) and lithium bis (oxalato) borate (LiBOB). 1ND1N-LiTFSI-VC-LiBOB was exposed to temperatures ranging from 30 ℃ to 185 ℃ and the decomposition products were analyzed by mass spectrometry. 1ND1N-LiTFSI-VC-LiBOB showed no gas phase decomposition products up to 185 ℃.¹H NMR showed that the hydrolysis increased from 3% (in the unheated sample) to 18.7% (after heating), most likely due to a delay before NMR analysis was performed.

FIG. 27 depicts LiBF containing₄Thermal stability of 1ND 1N. 1ND1N-LiBF₄Exposed to temperatures ranging from 30 ℃ to 125 ℃ and analyzed by mass spectrometry for decomposition products. The temperature at which the hump appears is noted. The gas phase product is discharged at the temperature of more than or equal to 30 ℃. As expected, Me was observed₂SiF₂(81 m/z) (96 g/mol). No acrylonitrile was observed.¹H NMR showed 3.7% hydrolysis and 34.2% fluorination product (group 3 peaks).¹⁹F NMR showed that all F in the system was bound to Si. Not remaining BF₄. There was not enough F to completely decompose 1ND1N (-5M 1ND1N vs 4M F).

Although in the heated 1ND1N-LiBF₄In the sample, no acrylonitrile was observed by mass spectrometry, but it was observed in the unheated control (70 ppm). This indicates the presence of LiBF at room temperature₄1ND1N is unstable. NMR analysis revealed that heating hardly increased decomposition, as shown in the table below:

performance of 1ND1N in battery:

fig. 28 depicts the discharge capacity of batteries containing various electrolytes at various discharge rates. The electrolyte solvent is: (1)1ND 1N; (2) 1ND1N (1ND1N _ EC) with 20% Ethylene Carbonate (EC) co-solvent; and (3) 1ND2 (1ND2_ EC) with 20% EC co-solvent. All formulations also contained SEI-forming additives and 1M LiPF₆And (3) salt. As shown in fig. 28, the 20% EC co-solvent improved the performance of 1ND 1N. 1ND with 20% EC cosolvent1N shows a decrease in performance at all discharge rates compared to 1ND 2.

Fig. 29 depicts the discharge capacity of batteries containing various other electrolyte solvents. The electrolyte solvent is: (1) containing 20% EC co-solvent, 1M LiPF₆And SEI-Forming additive 1ND1N (1ND 1N-EC-LiPF₆Shown in fig. 29 as 1ND1N _ EC); (2) 1ND1N containing 20% EC co-solvent, 1M LiTFSI and SEI-forming additives (1ND1N-EC-LiTFSI, shown in fig. 29 as 1ND1N _ T); and (3) 1M LiPF with 20% EC co-solvent₆And SEI-Forming additive 1ND2 (1ND2-EC-LiPF₆Shown in fig. 29 as CP 597-07). 1ND1N-EC-LiPF₆Combination and 1ND1N-EC-LiTFSI combination shows with 1ND2-EC-LiPF₆Combining comparable properties.

FIGS. 30A and 30B depict a composition containing 1ND1N-LiPF, respectively₆Discharge capacity of cells of-base electrolyte or 1ND 1N-LiTFSI-base electrolyte at various discharge rates. For each experiment, CR2032 coin cells with a soft America (cockaysville, MD) NCA cathode, a graphite anode, and 2500 separator plates from Celgard, LLC (Charlotte, NC) were used. The cells were charged to 4.1V using a constant current/constant voltage (CCCV) program at C/5, C/2, 1C, or 2C rates. The cells were discharged to 3.0V with constant current per cycle at the same rate they were once charged. In FIG. 30A, 1ND1N-LiPF₆-the base electrolyte solution comprises 1M LiPF₆And 1ND1N (batch ZP780-01), and charging/discharging was carried out at 30 ℃ or 55 ℃. In fig. 30B, the 1ND 1N-LiTFSI-based electrolyte solution contained 1M LiTFSI and 1ND1N, batch (ZT781-01), and charge/discharge was performed at 30 ℃, 55 ℃, or 70 ℃. As shown in FIGS. 30A and 30B, 1ND 1N-LiTFSI-based electrolyte showed a ratio to 1ND1N-LiPF₆Better rate performance of the base electrolyte.

Physical properties of OS solvent and electrolyte solution:

table 1 above shows selected Organosilicon (OS) compounds (1S)₃MN、F1S₃MN、F1S₃cMN、DF1S₃MN、DF1S₂MN and F1S₃M2) as pure solvent and as formulated electrolyte solutionPhysical properties. Table 2 above shows pure 1ND1N, 1ND1, 1ND2 and F1S₃MN and various electrolyte compositions containing them. In both tables, conductivity has units of mS/cm, viscosity has units of cP, and flash point is in degrees Celsius.

In CDCl₃Middle pairs of 1ND1N, 1ND1N and DF1S₂MN、DF1S₃MN、F1S₃cMN and 1S₃Proton of MN (¹H) NMR spectra are presented in FIGS. 31-36, respectively. For selected compounds containing fluorine atoms, in CDCl₃Neutralizing DMSO-d₆Middle collection¹⁹F-NMR data. The results are tabulated below:

and (4) conclusion:

F1S₃both MN and 1ND1N are suitable for use as electrolyte solvents in Li-ion batteries. F1S₃MN and DF1S₂MN has demonstrated a function as an electrolyte solvent in EDLC devices.

F1S containing all salts tested₃MN shows extremely high thermal stability¹H NMR measurement). F1S₃MN shows any LiPF containing₆The highest thermal stability (175 ℃) of OS of (1), and no decomposition is observed. As pure solvent, containing LiBF₄And F1S containing LiTFSI₃MN produces gas phase products. These gas phase products can be attributed to low levels of F1S₃The MN evaporates. And F1S₃M2 comparison, F1S₃MN shows increased voltage stability (higher oxidation potential with wide window). F1S₃MN provides equivalent performance to EPA6 at up to 4C rates. LiBOB in F1S without cosolvent₃Has limited solubility in MN (<0.03M), but with the use of a co-solvent (i.e. 20% EC), LiBOB solubility increases: (>0.1M)。F1S₃The decomposition product of MN is Me₂SiF₂And MeSiF₃Both of which are gases.

1ND1N doingEither as pure solvent or in combination with the LiTFSI electrolyte showed no gas phase decomposition up to 185-190 ℃. The combination of 1ND1N with LiTFSI electrolyte showed promise of reaching 70 ℃ and higher. Containing LiPF₆1ND1N ratio of (1) to (1) containing LiPF₆1ND1 or 1ND2 are more thermally stable. Which forms acrylonitrile above 125 ℃. As with other spacer-free compounds, 1ND1N was reacted with LiBF at room temperature₄And (4) reacting. However, there was not enough F to completely decompose 1ND1N, and it did not form acrylonitrile. The rate capability of 1ND1N is slightly lower than 1ND 2.

Claims (36)

1. A compound of formula I or formula II:

formula I

Formula II

Wherein R is¹、R²And R³Are identical or different and are independently selected from C₁-C₆Linear or branched alkyl and halogen;

"spacer" is absent or selected from C₁-C₆Linear or branched alkylene, provided that when "spacer" is absent, Y is present;

y is absent or selected from- (O-CH)₂-CH₂)_n-and

，

wherein each subscript "n" is the same or different and is an integer of from 1 to 15, and subscript "x" is an integer of from 1 to 15; and

each R⁴Are the same or different and are selected from the group consisting of cyanate (-OCN), isocyanate (-NCO), thiocyanate (-SCN) and isothiocyanate (-NCS).

2. The compound of claim 1, having a structure as shown in formula I:

formula I.

3. The compound of claim 2, wherein a "spacer" is present, and Y is- (O-CH)₂-CH₂)_n-。

4. The compound of claim 2 wherein a "spacer" is present and Y is

。

5. The compound of claim 2, wherein "spacer" is absent, and Y is- (O-CH)₂-CH₂)_n-。

6. The compound of claim 1, having a structure as shown in formula II:

formula II.

7. The compound of claim 6, wherein R¹And R³Is selected from C₁-C₃Alkyl, chloro and fluoro.

8. The compound of claim 6, wherein R¹And R³Is methyl.

9. The compound of claim 6, wherein each "n" is independently 1-5.

10. The compound of claim 1, having a structure as shown in formula III:

formula III.

11. The compound of claim 10, wherein R¹、R²And R³Is selected from C₁-C₃Alkyl, chloro and fluoro.

12. The compound of claim 10, wherein R¹、R²And R³At least one of (a) and (b) is halogen.

13. The compound of claim 10, wherein R¹、R²And R³Is halogen.

14. The compound of claim 10 wherein "spacer" is C₂-C₄Linear or branched alkylene.

15. The compound of claim 1, having a structure as shown in formula IV:

formula IV.

16. The compound of claim 15, wherein R¹、R²And R³Is selected from C₁-C₃Alkyl, chloro and fluoro.

17. The compound of claim 15, wherein R¹、R²And R³At least one of (a) and (b) is halogen.

18. The compound of claim 15, wherein R¹、R²And R³Is halogen.

19. The compound of claim 15, wherein "spacer" is C₂-C₄Linear or branched alkylene.

20. The compound of claim 15, wherein "x" is 1-4.

21. The compound of claim 1, having a structure as shown in formula V:

formula V.

22. The compound of claim 21, wherein R¹、R²And R³Is selected from C₁-C₃Alkyl, chloro and fluoro.

23. The compound of claim 21, wherein R¹、R²And R³At least one of (a) and (b) is halogen.

24. The compound of claim 21, wherein R¹、R²And R³Is halogen.

25. The compound of claim 21, wherein "spacer" is C₂-C₄Linear or branched alkylene.

26. The compound of claim 21, wherein "x" is 1-4.

27. An electrolyte composition comprising a compound as described in claim 1 in combination with a lithium-containing salt.

28. An electrochemical device comprising the electrolyte composition as recited in claim 27.

29. An electrolyte composition comprising a compound as recited in claim 6 in combination with a lithium-containing salt.

30. An electrochemical device comprising an electrolyte composition as recited in claim 29.

31. An electrolyte composition comprising a compound as recited in claim 10 in combination with a lithium-containing salt.

32. An electrochemical device comprising an electrolyte composition as recited in claim 31.

33. An electrolyte composition comprising a compound as recited in claim 15 in combination with a lithium-containing salt.

34. An electrochemical device comprising the electrolyte composition as recited in claim 33.

35. An electrolyte composition comprising a compound as recited in claim 21 in combination with a lithium-containing salt.

36. An electrochemical device comprising the electrolyte composition as recited in claim 35.