Electrolyte compositions and materials for safe high voltage lithium / sodium ion batteries

Abstract

Electrolyte compositions and materials are provided to promote stable cycling of LiNi < 0.8 > Mn < 0.1 > Co < 0.1 > O < 2 > / / graphite batteries at 4.7 V conditions. The electrolyte composition includes LiPF6, DEC, and MPIE in a molar ratio of 1: 3.94: 6.11, and FEC (referred to as s-DEC MPIE) in an addition amount of 4.67%. Due to the inherent incombustibility of the electrolyte containing fluorinated ether, the safety performance of the Ah-grade lithium ion soft package battery is improved, so that the soft package battery is ensured to pass a strict nail penetration test, and the thermal runaway temperature is increased by 20 DEG C in an acceleration calorimeter test. The electrolyte composition shows good industrial compatibility, and the ultrahigh pressure stability and safety performance are greatly improved from the material level to the actual Ah soft package battery level.

Description

Background Technology

[0001] Lithium-ion batteries (LIBs) have revolutionized the way we use energy and are now used in a wide range of portable electronic devices, electric vehicles (EVs), and energy storage stations in our daily lives. 1,2 Recently, in order to address the range anxiety of EVs, the energy density requirements for lithium-ion batteries (LIBs) have increased. This will require a higher cutoff voltage (>4.5V), which will squeeze more lithium out of the cathode crystal. + This will increase energy density by approximately 20%. 3,4 However, traditional electrolytes cannot achieve this goal because continuous parasitic interfacial reactions occur when the voltage exceeds 4.3V. 5,6 Although many strategies have been reported, including adding additives... 7–9 Cathode interface modification 10–13 and solvent molecule design 14–16 However, the performance above 4.5V is still unsatisfactory.

[0002] As energy density increases, safety should be the top priority, because when batteries are abused, all energy will be more easily converted into heat, which will eventually ignite organic vapors and lead to thermal runaway. 17 To inertize organic solvents such as ethylene carbonate (EC) or diethyl carbonate (DEC), the use of flame-retardant (FR) materials has been proposed to control flammability by utilizing free radical scavengers. 18,19 Although they demonstrate significant performance in flame ignition tests, there are few reports of practical demonstrations of safe Ah-class batteries under thermal and mechanical abuse conditions. These challenges can be attributed to two main factors. First, the addition of flame-retardant (FR) materials often compromises interfacial stability. 20 This will increase heat release and ultimately accelerate thermal runaway. 21 Secondly, due to the physical properties of electrolytes (such as viscosity) and their extremely high price, the recommended electrolytes are incompatible with current industry technologies. 22,23 . Summary of the Invention

[0003] Embodiments of the present invention relate to safe high-voltage electrolyte compositions and materials for lithium / sodium-ion batteries.

[0004] According to one embodiment of the present invention, an electrolyte composition for lithium / sodium-ion batteries is provided. The composition comprises: a salt; a solvent; a fluoride; and additives. The salt content is between 5% and 20% by weight. The salt may include: lithium hexafluorophosphate (LiPF6, CAS: 21324-40-3), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI, CAS: 90076-65-6), lithium bis(fluorosulfonyl)imide (LiFSI, CAS: 171611-11-3), sodium hexafluorophosphate (NaPF6, CAS: 21324-39-0), sodium bis(trifluoromethanesulfonyl)imide (NaTFSI, CAS: 91742-21-1), sodium bis(fluorosulfonyl)imide (NaFSI, CAS: 100669-96-3), or any combination thereof. Furthermore, the solvent content is between 10% and 40% by weight. The solvent comprises one or more organic liquids having carbonate or ether groups. Furthermore, the weight percentage of fluoride is between 30% and 80%. The fluoride includes one or more fluorinated ethers, fluorocarbons, or fluorinated esters. Additionally, the weight percentage of additives is between 0% and 10%. The additives are one or more selected from the group consisting of unsaturated carbonates, unsaturated sulfonates, silicon-based compounds, and lithium salts.

[0005] In another embodiment of the present invention, a method for preparing an electrolyte for a lithium / sodium-ion battery is provided, the method comprising: dissolving a first predetermined amount of LiPF6 in a second predetermined amount of diethyl carbonate (DEC) solvent to form a clear solution; adding a third predetermined amount of perfluoroisobutyl methyl ether (MPIE), a fourth predetermined amount of fluoroethylene carbonate (FEC), and a fifth predetermined amount of DEC to a sixth predetermined amount of the clear solution to form a mixture; and uniformly mixing the mixture. The first predetermined amount may be 3 mmol. The second predetermined amount may be 1 ml. The third predetermined amount may be 4 g. The fourth predetermined amount may be 0.19 ml. The fifth predetermined amount may be 0.38 ml. The sixth predetermined amount may be 1 ml. Attached Figure Description

[0006] Figure 1A-1B The diagram shows oxidative stability curves of commercially available and s-DEC MPIE electrolytes according to an embodiment of the present invention, wherein... Figure 1A The leakage current of the electrolyte is shown after being charged to 5V and held for 48 hours. Figure 1B The voltage curves of the two electrolytes are shown after charging to 4.7V and then letting them stand for 3 hours.

[0007] Figure 2A-2D The diagram illustrates LiNi at 4.7V, according to an embodiment of the present invention. 0.8 Mn 0.1 Co 0.1The graphs show the cycle stability of O2 / / graphite (811 / / Gr) batteries in commercially available and s-DEC MPIE electrolytes. Figure 2A The charge-discharge curves of the battery in a commercially available electrolyte from the first to the 500th cycle are shown; among them, Figure 2B The charge-discharge curves of the battery in s-DECMPIE electrolyte from the first to the 500th cycle are shown; among them, Figure 2C The cycling performance of the battery in commercially available and s-DEC MPIE electrolytes is shown at a 2C rate; where, Figure 2D The battery's cycle performance at 1C in commercially available and s-DEC MPIE electrolytes is shown under a pause procedure (charged to 4.7V and left to rest for 3 hours).

[0008] Figures 3A-3B The following graph shows the cycling performance of a 1Ah pouch cell according to an embodiment of the present invention in commercially available and s-DEC MPIE electrolytes, wherein... Figure 3A The cycle performance of a 1Ah pouch cell after three formation cycles at a voltage of 2.7-4.7V and a current of 300mA using a commercially available electrolyte is shown; among them, Figure 3B The cycling performance of a 1Ah pouch cell in s-DECMPIE electrolyte at a voltage of 2.7–4.7 V and a current of 300 mA is shown.

[0009] Figure 4A-4J The results of cathode interface characterization according to an embodiment of the present invention are shown, wherein, Figures 4A-4B LiNi was shown 0.8 Mn 0.1 Co 0.1 Transmission electron microscopy characterization of the O2 cathode after 100 cycles in a commercial electrolyte at voltages of 2.7–4.7 V; among which, Figure 4C The electrochemical impedance spectroscopy (EIS) spectra of the 811 / / Gr battery after 50 and 200 cycles in a commercially available electrolyte are shown; among them, Figure 4D-4E LiNi was shown 0.8 Mn 0.1 Co 0.1 The O2 cathode was characterized by transmission electron microscopy after 100 cycles in s-DEC MPIE electrolyte at voltages of 2.7–4.7 V; among which, Figure 4F The electrochemical impedance spectroscopy (EIS) spectra of the 811 / / Gr battery after 50 and 200 cycles are shown; among them, Figure 4G-4J The X-ray photoelectron spectra of the F 1s, Li 1s, C 1s, and O 1s orbitals on the cathode are shown after 100 cycles in commercially available and s-DEC MPIE electrolytes.

[0010] Figures 5A-5F The results of a safety demonstration test of the s-DEC MPIE electrolyte according to an embodiment of the present invention are shown, wherein, Figure 5A It shows 5℃s -1 Differential scanning calorimetry (DSC) tests were performed on charged NCM811 and lithium-ion graphite in a gold-plated crucible using 1 µl of electrolyte at a heating rate of [value missing]. Figure 5B The voltage and temperature profiles of a 1Ah pouch cell using a commercially available electrolyte during nail penetration tests are shown, along with digital images of the pouch cell after the nail penetration tests; Figure 5C The voltage and temperature profiles of a 1Ah pouch cell using s-DEC MPIE electrolyte during a nail penetration test are shown, along with a digital image of the pouch cell after the nail penetration test; and in which, Figure 5D-5F Accelerated calorimetry testing of a 1Ah pouch cell using commercially available and s-DECMPIE electrolyte is shown. Detailed Implementation

[0011] Embodiments of the present invention relate to an electrolyte composition for lithium / sodium ion batteries and a method for preparing the electrolyte.

[0012] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. As used herein, the singular forms "an," "a," and "the" are intended to include both the plural and singular forms unless the context clearly indicates otherwise. It will be further understood that the terms "comprising" and / or "including" as used herein specify the presence of the stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof.

[0013] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the relevant art and in the context of this disclosure, and shall not be interpreted in an idealized or overly formal manner unless expressly defined herein.

[0014] When the term “about” is used in conjunction with a numerical value in this document, it should be understood that the value may be between 90% and 110% of that value, i.e., the value may be + / - 10% of the stated value. For example, “about 1 kg” means 0.90 kg to 1.1 kg.

[0015] Electrolytes, considered the "blood of electrochemistry," play a crucial role in lithium / sodium-ion batteries. However, traditional electrolyte solvents (carbonates) exhibit low oxidative stability (below 4.3V vs. Li). + The high flammability of Li (Li) hinders its energy density and safety performance.

[0016] To enable compatibility with ultra-high voltages and safe use in practical batteries, an electrolyte composition is provided comprising a LiPF6 salt, a DEC solvent, perfluoroisobutyl methyl ether (MPIE), and a fluoroethylene carbonate (FEC) additive. This electrolyte exhibits superior oxidation resistance and supports LiNi... 0.8 Mn 0.1 Co 0.1 O2 / / Stable cycling of graphite batteries at 4.7V. Furthermore, due to the significant addition of flammable inert MPIE, this electrolyte enabled a 1Ah pouch cell to successfully pass a nail penetration test without ignition and significantly reduced thermal runaway temperature by 20°C in accelerated calorimetry (ARC) testing. o C. This low-cost electrolyte composition exhibits excellent industrial compatibility and demonstrates great commercial potential for ultra-high voltage and practically safe batteries.

[0017] Materials and methods Materials: Lithium hexafluorophosphate (LiPF6, 98%), diethyl carbonate (DEC, 98%), and ethylene carbonate (EC, 98%) were purchased from TCI. Fluorinated ethylene carbonate (FEC, 99%) was purchased from Canrd. Perfluoroisobutyl methyl ether (MPIE) was purchased from ShangFluoro. Salts were used as is, and all solvents were dried over 4 Å molecular sieves for at least 4 days before use.

[0018] Electrodes and dry-state pouch cell: NCM811 cathode (8.3 mg cm⁻¹) -2 ) and graphite anode (5.8 mg cm -2 The electrodes were purchased from Canrd. These electrodes were packaged into 12mm and 13mm diameter disks and were ready for use after being dried overnight in a vacuum oven. Approximately 1Ah of dry-state NCM811 / / Gr pouch cells were purchased from Canrd and LiFun New Energy, with NCM811 cathode loading of 13-15 mg cm⁻¹. -2 The dimensions are approximately 51mm*66mm.

[0019] Electrolyte preparation: To prepare the s-DEC MPIE electrolyte, 3 mmol of LiPF6 was first dissolved in 1 ml of DEC solvent to form a clear solution. Then, 4 g of MPIE, 0.19 ml of FEC, and 0.38 ml of DEC were added to the 1 ml solution. All components were mixed uniformly to obtain the s-DEC MPIE electrolyte. A commercially available electrolyte was prepared by dissolving LiPF6 in a mixture of EC and DEC (weight ratio 3:7) to obtain EC DEC containing 1 M LiPF6.

[0020] Electrochemical characteristics: CR2032 coin cells were assembled in a glove box with oxygen and moisture concentrations below 0.1 ppm. A 19 mm Celgard 2500 separator was sandwiched between an NCM 811 cathode and a graphite anode. 40 µl of electrolyte was added to ensure separator wettability. Charge-discharge was performed by cycling at 0.2C for 3 cycles, 0.5C for 5 cycles, and 1C for 5 cycles at 2.7–4.7 V, followed by a subsequent cycle at 2C, where 1C equals 200 mA g. -1 For the pause procedure, charge the battery to 4.7V, then let it rest for 3 hours, and then discharge it at a rate of 1C. For the manufacture of pouch batteries, first, use 3.8g Ah... -1 Electrolyte was injected into the dry-state pouch cell, which was then sealed and left to stand overnight. The pouch cell was vacuum-sealed and cycled under pressure in a stainless steel pouch cell clamp. For commercially available electrolytes, the pouch cell was first charged and discharged for three cycles at 200 mA within a voltage range of 2.7–4.5 V. After degassing and vacuum sealing, the pouch cell was ready for subsequent long-term cycling. Leakage current testing was performed as follows: one cycle of charge and discharge was performed at 0.2 C between 2.7–4.7 V, followed by charging to 5 V and holding for 48 hours. EIS testing was conducted at frequencies from 200 kHz to 0.1 Hz. All electrochemical measurements were performed on a NEWARE battery testing system (NEWARE Technologies) and a VMP3 electrochemical testing device (Bio-Logic, France).

[0021] Material characterization: XPS was performed on Thermo Scientific K-Alpha+ using Al Kα radiation. The cycled cathode sample was then subjected to Ar... + XPS data were collected every 10 seconds after sputtering for 30 seconds. The obtained XPS values ​​were calibrated using C 1s at 284.8 eV. The morphology of the cycled cathode samples was studied using a high-resolution transmission electron microscope (JEM-3200FS, JEOL). DSC tests were performed in a DSC200F3 at a heating rate of 10 K min from 25 °C to 400 °C.-1 .

[0022] Safety features: A nail puncture test was conducted using the following method: a 5mm diameter nail (nail taper: 30 degrees) was driven into the nail at a 20mm penetration. -1 The moving part punctured a fully charged pouch cell (charged to 4.5V after one cycle at 0.2C). Two thermocouples were installed at the top and bottom of the pouch cell near the puncture site to record temperature changes. The ARC test used a heat-wait-search mode with a temperature increment of 5°C and a waiting time of 30 minutes.

[0023] result The electrolyte composition comprises LiPF6, DEC, MPIE, and FEC, wherein the molar ratio of LiPF6, DEC, and MPIE is 1:3.94:6.11, and the amount of FEC added is 4.67%. This electrolyte composition is referred to as s-DEC MPIE. The control group is a commercially available electrolyte (1M LiPF6, EC: DEC = 3:7, by weight). To compare high-pressure stability, [the following was observed] in LiNi... 0.8 Mn 0.1 Co 0.1 Leakage current and self-discharge tests were performed on the O2 / / graphite (811 / / Gr) button cell, such as Figure 1A-1B As shown. After charging to 5V and maintaining that voltage for 48 hours, the measured leakage current of the battery in the commercially available electrolyte was 4.2 µA mg. -1 The measured value of s-DEC MPIE was 1.3 µA mg. -1 ,like Figure 1A As shown. Self-discharge testing also showed a significant voltage difference after charging to 4.7V and then resting for 3 hours. (As illustrated...) Figure 1B As shown, the terminal voltage of the battery in s-DEC MPIE is 50 mV higher than that in commercially available electrolytes. These results indicate a reduction in parasitic reactions at the cathode interface and demonstrate that the antioxidant performance of s-DEC MPIE is significantly superior to that of commercially available electrolytes.

[0024] LiNi using commercially available and s-DEC MPIE electrolytes 0.8 Mn 0.1 Co 0.1 Cyclic performance tests were conducted on the O2 / / graphite battery to further evaluate the oxidative stability of the two electrolytes, such as... Figure 2A-2D As shown. Figure 2A As shown, when using a commercially available electrolyte, significant degradation can be detected at 4.7V based on the charge-discharge curve. However, when the commercially available electrolyte is replaced with the s-DEC MPIE electrolyte, as... Figure 2BAs shown, the noticeable degradation and polarization are negligible, indicating a significant improvement in the oxidation resistance of the s-DECMPIE electrolyte. Antioxidant electrolytes play a crucial role in battery performance. From Figure 2C Similar results were obtained in the s-DEC MPIE. The battery exhibited excellent cycle stability, cycling 1289 times before reaching 80% of its initial capacity, compared to 384 cycles for batteries using commercially available electrolytes. To simulate real-world applications of lithium-ion batteries, the battery was exposed to a fully charged state for 3 hours during cycling to accelerate its degradation. 24 . Figure 2D It was shown that batteries using commercially available electrolytes could not withstand 182 cycles, while batteries using s-DEC MPIE exhibited stable performance of over 500 cycles, achieving a high-voltage calendar life of 2,500 hours.

[0025] In addition, 1Ah commercially available dry-state pouch cells without electrolyte were collected to demonstrate the industry compatibility and commercialization potential of the s-DEC MPIE electrolyte. 3.8 g Ah was injected. -1 After the electrolyte is sealed, the pouch cell battery with the commercially available electrolyte is first subjected to three charge-discharge cycles for formation. Then, the formation gas is evacuated, and the pouch cell battery is resealed for further cycling. Pouch cells using commercially available electrolytes show significant degradation before 100 cycles, and after 100 cycles, they suddenly deteriorate due to a rapid decrease in coulombic efficiency. Figure 3A As shown, this may be attributed to the low oxidation stability of commercially available electrolytes and the parasitic reactive gases that accumulate inside pouch cells. 25,26 For pouch cells using s-DEC MPIE electrolytes, such as Figure 3B As shown, it can be directly cycled without a formation process, and the changes detected in the charge-discharge curves from the 1st to the 120th cycle are negligible, exhibiting perfect capacity retention and high voltage stability.

[0026] To further demonstrate the interfacial stability of the s-DEC MPIE electrolyte, transmission electron microscopy (TEM) was used. After 100 cycles in a commercially available electrolyte, as... Figures 4A-4B As shown, a non-uniform and relatively thick cathode-electrolyte interphase (CEI) of approximately 5.2 nm can be clearly detected in the TEM image, indicating severe parasitic reactions during high-voltage cycling. The thick interphase layer blocks lithium-ion transport channels, leading to increased resistance and rapid degradation. In contrast, the TEM image of the cathode after 100 cycles in the s-DEC MPIE electrolyte shows a uniform CEI layer of approximately 1.5 nm thick covering the cathode, indicating significant protection and isolation between the cathode and the electrolyte. Figure 4D-4F As shown. CEI evolution can also be assessed using the first half-circle of electrochemical impedance spectroscopy (EIS), such as... Figure 4C and Figure 4F As shown 27–29 After 200 cycles in a commercially available electrolyte, the resistance (R) of the CEI layer at the cathode... SEI The resistance was significantly higher than after 50 cycles, indicating that the CEI layer gradually thickened. However, the R of the battery in the s-DEC MPIE electrolyte was significantly higher. SEI The interfacial composition remained almost unchanged between 50 and 200 cycles, indicating that the s-DEC MPIE electrolyte possesses excellent interfacial stability and superior oxidation resistance. X-ray photoelectron spectroscopy (XPS) was used to investigate the interfacial composition within the CEI layer, with XPS data collected every 10 seconds during Ar+ sputtering. Compared to cathodes cycled in commercially available electrolytes, the cathode surface cycled in the s-DEC MPIE electrolyte showed more LiF signal (F 1s at 685.0 eV and Li 1s at 56.4 eV). 30,31 And less organic component signal CO (C 1s at 286.5 eV) 32 ,like Figure 4G , 4H As shown in Figure 4I, due to the wide band gap of LiF (13.6 eV), the increased LiF content and reduced organic components from the s-DEC MPIE electrolyte in the CEI layer can significantly improve electronic insulation properties and enhance oxidation stability. 33 .like Figure 4J As shown, in Ar + Thirty seconds after sputtering, a TM-O signal (O 1s at 530.0 eV) was clearly visible on the cathode surface circulating in a commercially available electrolyte. 34 This indicates that an initial reaction occurred between the commercially available electrolyte and the cathode surface, resulting in the embedding of transition metal material within the CEI layer.

[0027] The safety performance of the s-DEC MPIE electrolyte was fully demonstrated from the material level to the actual Ah pouch battery level. The overall exothermic performance was evaluated using differential scanning calorimetry (DSC). A charged NCM cathode, an electrolyte-containing separator, and charged graphite were sealed in a gold-plated crucible in the form of a coin cell and incubated at 10 °C for [time missing]. -1 Heating rate. DSC testing using a commercially available electrolyte showed a sharp exothermic peak at 220°C, such as... Figure 5A As shown, this illustrates the reaction trends at unstable interfaces in commercially available electrolytes. (As...) Figure 5BAs shown, the heat release in the s-DEC MPIE electrolyte is delayed by 20°C, and the exothermic rate is much slower, which further demonstrates the electrolyte's antioxidant capacity and more stable interface containing derived LiF. A nail penetration test was conducted on a 1Ah 811 / / Gr pouch battery after charging to study its actual safety performance under mechanical abuse conditions. The pouch battery using the commercially available electrolyte caught fire within 3 seconds of nail penetration, with the temperature rising to 450°C. The pouch battery was severely charred, as shown in the image. Figure 5A As shown. The pouch cell using the s-DEC MPIE electrolyte remained intact after the nail puncture, with the temperature slowly rising to 80°C and then cooling to room temperature, as... Figure 5B As shown, the thermal abuse of a 1Ah pouch cell after charging was studied using accelerated calorimetry (ARC). The onset temperature T1 and thermal runaway temperature T2 were used to describe the cell's thermal behavior. 17,35 .like Figure 5D As shown, the T1 of the pouch cell using s-DEC MPIE electrolyte is 116°C, approximately 20°C higher than comparable commercially available products. This indicates that eliminating the reducing components of EC or LiFSI can significantly increase the onset temperature in practical battery systems. Additionally, as... Figure 5D As shown, the T2 (cathode oxygen release and reaction temperature) of the pouch cell using s-DEC MPIE electrolyte is 8°C higher than that of commercially available cells, further demonstrating the effective interface and higher oxidation stability of the s-DEC MPIE electrolyte at the cathode. Figure 5E As shown, the use of s-DEC MPIE electrolyte also significantly reduced the temperature rise rate, attributed to the large addition of MPIE containing flame radical scavengers. Therefore, s-DEC MPIE electrolyte exhibits excellent safety performance from the material level to the practical Ah pouch cell level.

[0028] According to embodiments of the present invention, the s-DEC MPIE electrolyte exhibits significantly improved oxidation stability compared to commercially available electrolytes, thereby supporting extremely stable cycle performance of NCM811 / / Gr batteries at 4.7V. Furthermore, the electrolyte of the present invention demonstrates significant safety performance from the material level to the Ah pouch cell level, ensuring that Ah pouch cells pass the nail penetration test and that the thermal runaway temperature in the ARC test is 20°C higher than that of commercially available electrolytes. The s-DEC MPIE electrolyte also exhibits good industrial compatibility in terms of physical properties and cost, thus possessing enormous scalability potential for the commercial application of lithium / sodium-ion batteries.

[0029] Example 1. An electrolyte composition for lithium / sodium ion batteries, the composition comprising: At least one salt; At least one solvent; At least one fluoride; and Optionally, one or more additives may be used.

[0030] Example 2. The composition according to Example 1, wherein the weight percentage of the salt is between 5% and 20%.

[0031] Example 3. The composition according to Example 1, wherein the salt comprises: lithium hexafluorophosphate (LiPF6, CAS: 21324-40-3), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI, CAS: 90076-65-6), lithium bis(fluorosulfonyl)imide (LiFSI, CAS: 171611-11-3), sodium hexafluorophosphate (NaPF6, CAS: 21324-39-0), sodium bis(trifluoromethanesulfonyl)imide (NaTFSI, CAS: 91742-21-1), and sodium bis(fluorosulfonyl)imide (NaFSI, CAS: 100669-96-3).

[0032] Example 4. The composition according to Example 1, wherein the weight percentage of the solvent is between 10% and 40%.

[0033] Example 5. The composition according to Example 1, wherein the solvent comprises one or more organic liquids having carbonate or ether groups.

[0034] Example 6. The composition according to Example 5, wherein the carbonate or ether group includes, but is not limited to: Carbonates:

[0035] ether:

[0036] Example 7. The composition according to Example 1, wherein the weight percentage of the fluoride is between 30% and 80%.

[0037] Example 8. The composition according to Example 1, wherein the fluoride comprises one or more fluorinated ethers, fluorocarbons, or fluorinated esters.

[0038] Example 9. The composition according to Example 8, wherein one or more fluorinated ethers, fluorocarbons, or fluorinated esters include, but are not limited to: Fluorinated ethers:

[0039] Fluorocarbons / fluorinated esters:

[0040] Example 10. The composition according to Example 1, wherein the weight percentage of the additive is less than or equal to 10%.

[0041] Example 11. The composition according to Example 1, wherein one or more additives are selected from unsaturated carbonates, unsaturated sulfonates, silicon-based compounds or lithium salts.

[0042] Example 12. The composition according to Example 11, wherein one or more unsaturated carbonates, unsaturated sulfonates, silicon-based compounds, or lithium salts include, but are not limited to: additive:

[0043] Example 13. A method for preparing an electrolyte for lithium / sodium-ion batteries, the method comprising: A first predetermined amount of LiPF6 is dissolved in a second predetermined amount of DEC solvent to form a clear solution; A third predetermined amount of MPIE, a fourth predetermined amount of FEC, and a fifth predetermined amount of DEC are added to a sixth predetermined amount of clarified solution to form a mixture; and Mix the mixture thoroughly.

[0044] Example 14. The method according to Example 13, wherein the first predetermined amount is 3 mmol.

[0045] Example 15. The method according to Example 13, wherein the second predetermined amount is 1 ml.

[0046] Example 16. The method according to Example 13, wherein the third predetermined amount is 4g.

[0047] Example 17. The method according to Example 13, wherein the fourth predetermined amount is 0.19 ml.

[0048] Example 18. The method according to Example 13, wherein the fifth predetermined amount is 0.38 ml.

[0049] Example 19. The method according to Example 13, wherein the sixth predetermined amount is 1 ml.

[0050] All patents, patent applications, provisional applications and publications mentioned or cited herein are incorporated in their entirety as references, including all figures and tables, provided that they do not contradict the express teachings of this specification.

[0051] It should be understood that the examples and embodiments described herein are for illustrative purposes only, and those skilled in the art can make various modifications or alterations based thereon. All such modifications or alterations should be covered within the spirit and scope of this application and the appended claims. Furthermore, any element or limitation of any invention or embodiment disclosed herein may be combined with any element or limitation (alone or in any combination) of any and / or all other inventions or embodiments disclosed herein, and all such combinations are covered within the scope of this invention, but are not limited thereto.

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Claims

1. An electrolyte composition for lithium / sodium-ion batteries, said composition comprising: At least one salt; At least one solvent; At least one fluoride; as well as Optionally, one or more additives may be used.

2. The composition according to claim 1, wherein, The salt contains between 5% and 20% by weight.

3. The composition according to claim 1, wherein, The salt is selected from one or more of the following: lithium hexafluorophosphate (LiPF6, CAS: 21324-40-3), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI, CAS: 90076-65-6), lithium bis(fluorosulfonyl)imide (LiFSI, CAS: 171611-11-3), sodium hexafluorophosphate (NaPF6, CAS: 21324-39-0), sodium bis(trifluoromethanesulfonyl)imide (NaTFSI, CAS: 91742-21-1), and sodium bis(fluorosulfonyl)imide (NaFSI, CAS: 100669-96-3).

4. The composition according to claim 1, wherein, The solvent accounts for between 10% and 40% by weight.

5. The composition according to claim 1, wherein, The solvent includes one or more organic liquids having carbonate or ether groups.

6. The composition according to claim 5, wherein, The solvent comprising one or more carbonate or ether groups is selected from one or more of the following: Carbonates: ether: 。 7. The composition according to claim 1, wherein, The weight percentage of the fluoride is between 30% and 80%.

8. The composition according to claim 1, wherein, The fluoride includes one or more fluorinated ethers or fluorocarbons / fluorinated esters.

9. The composition according to claim 8, wherein, The fluorinated ether or fluorocarbon / fluorinated ester is selected from one or more of the following: Fluorinated ethers: Fluorocarbons / fluorinated esters: 。 10. The composition according to claim 1, wherein, The additive's weight percentage is less than or equal to 10%.

11. The composition according to claim 1, wherein, The additive is selected from one or more of the group consisting of unsaturated carbonates, unsaturated sulfonates, silicon-based compounds and lithium salts.

12. The composition according to claim 11, wherein, The one or more unsaturated carbonates, unsaturated sulfonates, silicon-based compounds, or lithium salts are selected from: additive: 。 13. A method for preparing an electrolyte for lithium / sodium-ion batteries, the method comprising: A first predetermined amount of LiPF6 is dissolved in a second predetermined amount of DEC solvent to form a clear solution; A third predetermined amount of MPIE, a fourth predetermined amount of FEC, and a fifth predetermined amount of DEC are added to a sixth predetermined amount of the clarified solution to form a mixture; as well as Mix the mixture evenly.

14. The method according to claim 13, wherein, The first predetermined amount is 3 mmol.

15. The method according to claim 13, wherein, The second predetermined amount is 1 ml.

16. The method according to claim 13, wherein, The third predetermined amount is 4g.

17. The method according to claim 13, wherein, The fourth predetermined amount is 0.19 ml.

18. The method according to claim 13, wherein, The fifth predetermined amount is 0.38 ml.

19. The method according to claim 13, wherein, The sixth predetermined amount is 1 ml.

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