Electrolyte of compound containing nitrogen and sulfur atoms and energy storage device containing electrolyte

Abstract

The invention provides an electrolyte of a compound containing nitrogen and sulfur atoms and an energy storage device containing the electrolyte, and belongs to the technical field of electrochemical energy storage. The electrolyte of the compound containing nitrogen and sulfur atoms comprises an electrolyte, an organic solvent and an additive, the additive comprises a nitrogen and sulfur atom-containing compound with a structure as shown in a formula I. By adding the nitrogen and sulfur atom-containing compound with the structure as shown in the formula I in the electrolyte, the cycle life of the obtained energy storage device can be obviously prolonged while good first charge-discharge efficiency, high-rate discharge performance, low-temperature discharge characteristic and high-temperature storage performance are maintained, the safety performance is good, and the comprehensive performance is excellent.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrochemical energy storage, in particular to an electrolyte containing a nitrogen and sulfur atom compound and an energy storage device comprising the same. BACKGROUND

[0002] Currently, sodium batteries and lithium batteries use film-forming agents for positive and negative electrodes. The negative electrode uses an oxidizing agent with electron-accepting ability, such as vinyl sulfate, which is reduced to an organic sulfur-containing salt film during formation. The positive electrode uses a reducing agent with electron-donating ability, such as tris(trimethylsilyl) phosphate (TMSP), which is oxidized to a phosphate film during formation. The current film-forming technology has the following problems: (1) The film-forming agents for positive and negative electrodes consume active ions during the first formation process, reducing the first charge / discharge efficiency and the battery capacity performance. (2) The negative electrode film-forming agent with high reactivity is unstable. For example, vinyl sulfate (DTD) is an unstable compound formed from sulfur trioxide and ethylene oxide, which can undergo a self-decomposition reaction. To reduce the self-decomposition reaction rate, it needs to be stored at low temperature, and the shelf life is short. (3) There is an interaction between the negative electrode film-forming agent with high electrochemical reactivity and the positive electrode film-forming agent. When they are mixed together, they will react with each other over time, reducing the film-forming effect.

[0003] Lu et al. (Lu Y, Cao Q, Zhang W. et al. Breaking the molecular symmetricity of sulfonimide anions for high-performance lithium metal batteries under extreme cycling conditions [J]. Nature Energy, 2025, 10(2): 191-204. DOI: 10.1038 / s41560-024-01679-4.) designed and synthesized a class of asymmetric sulfonimidate lithium salt LiSTFSI, which can construct anion-derived interfacial chemistry on the positive electrode surface, with ultra-high power discharge performance and low temperature characteristics. However, the asymmetric salt structure is complex, the synthesis cost is high, and it is difficult to popularize in industry. Zheng et al. (Zheng T, Zhu B, Xiong J, et al. When audience takes stage: Pseudo-localized-high-concentration electrolyte with lithium nitrate as the only salt enables lithium metal batteries with excellent temperature and cathode adaptability [J]. Energy Storage Materials, 2023, 59(000): 10. DOI: 10.1016 / j.ensm.2023.102782.) developed a high-concentration electrolyte PLHCE, which selected inexpensive and less corrosive lithium nitrate (LiNO3) as the only salt. Since LiNO3 is difficult to dissolve in most carbonate solvents such as ethylene carbonate (EC), propylene carbonate (PC), fluoroethylene carbonate (FEC), and dimethyl carbonate (DMC), triethyl phosphate (TEP) was used to dissolve lithium nitrate, which has a high donor number and is suitable for high temperature and high pressure applications.Liao et al. (Liao C, Han L, Wang W, et al. Non-Flammable Electrolyte with Lithium Nitrate as the Only Lithium Salt for Boosting Ultra-Stable Cycling and Fire-Safety Lithium Metal Batteries [J]. Advanced functional materials, 2023. DOI: 10.1002 / adfm.202212605.) used LiNO3 as a lithium salt dissolved in TEP and FEC co-solvents for lithium metal battery systems, which can exhibit good fire resistance and stable long cycle performance. However, the above-mentioned scheme all has the problem that LiNO3 is difficult to dissolve in ester solvents that can withstand high voltage, so that it is difficult to play its due role due to the small amount of dissolution. And dissolved in TEP, it is difficult to meet the requirements of practical application due to the strong deterioration of TEP on battery performance.

[0004] Therefore, it is of great significance to design and develop a simple electrolyte structure that can make the energy storage device have good charge-discharge cycle performance, excellent high-low temperature characteristics and safety. SUMMARY

[0005] To solve the above technical problems, the present application provides an electrolyte containing a nitrogen and sulfur atom compound and an energy storage device containing the same. The electrolyte containing a nitrogen and sulfur atom compound can improve the first charge-discharge efficiency, storage performance, charge performance of the battery, large-rate discharge performance, charge-discharge cycle life of the obtained energy storage device, and also has excellent high-low temperature characteristics and safety performance, while it can also reduce the internal resistance of the energy storage device.

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides an electrolyte containing a nitrogen and sulfur atom compound, which comprises an electrolyte, an organic solvent and an additive; the additive comprises a nitrogen and sulfur atom compound with the structure of formula I:

[0008]

[0009] wherein R1 is selected from substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C2-C6 alkenyl, substituted or unsubstituted C2-C6 alkynyl, substituted or unsubstituted C6-C20 aryl;

[0010] R2 is selected from halogen, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C2-C6 alkenyl, substituted or unsubstituted C2-C6 alkynyl, substituted or unsubstituted C6-C20 aryl;

[0011] X is selected from alkali metal;

[0012] The substituted substituent is selected from at least one of fluorine, C1-C4 alkyl, C1-C4 alkoxy or C2-C4 alkenyl.

[0013] The energy storage device composed of the electrolyte can obtain a lower internal resistance, and can significantly improve the cycle life and safety performance while maintaining good first charge-discharge efficiency, high-rate discharge performance, low-temperature discharge characteristics and high-temperature storage performance, and has excellent comprehensive performance.

[0014] The sulfur and nitrogen-containing compound in the application is an asymmetric compound composed of a nitrogen atom center group and a sulfur atom center group, wherein the nitrogen-containing group is easily reduced to a lithium-nitrogen compound on the negative electrode, and the sulfur-containing group is suspended in the electrolyte, and the oxygen on the sulfur-oxygen double bond is negatively charged, which can pierce the solvated lithium ion bubble, and introduce lithium ions into the negative electrode or the electrolyte, greatly reducing the interface resistance of lithium ion transmission; similarly, the sulfur-containing group is oxidized to a sulfate salt and solidified on the positive electrode surface, and the nitrogen-containing group is suspended in the electrolyte, and the oxygen on the nitrogen-oxygen double bond plays a similar role, thereby forming a double-layer inorganic CEI derived from anions, which has excellent mechanical stability and accelerated interface kinetics. By introducing the nitrogen and sulfur-containing compound with the specific structure as an additive into the electrolyte, the lithium ion soft pack battery formed thereby can exhibit unprecedented energy and power density under various extreme temperature and current conditions, thereby ensuring good battery performance, and also having excellent flame resistance and stable long cycle performance.

[0015] In the application, the C1-C6 alkyl can be C1, C2, C3, C4, C5 or C6 alkyl, the C2-C6 alkenyl can be C2, C3, C4, C5 or C6 alkenyl, the C2-C6 alkynyl can be C2, C3, C4, C5 or C6 alkynyl, and the C6-C20 aryl can be C6, C8, C10, C12, C14, C16, C18 or C20 aryl.

[0016] The following is a preferred technical solution of the application, but is not a limitation on the technical solutions provided by the application. Through the following preferred technical solution, the purpose and beneficial effects of the application can be better achieved and realized.

[0017] R1is selected from any one of methyl, ethyl or fluorine-substituted C1-C2 alkyl;

[0018] R2is selected from any one of F, methyl, ethyl or fluorine-substituted C1-C2 alkyl;

[0019] X is any one of Li, Na or K.

[0020] As a preferred technical solution of the present application, the mass percentage content of the additive is 0.2-15% based on 100% of the mass percentage content of the electrolyte, for example, it can be 0.2%, 0.4%, 0.6%, 0.8%, 1%, 3%, 5%, 8%, 10%, 12% or 15%, and specific point values between the above point values, limited by the length and for the sake of simplicity, the present application does not exhaustively list the specific point values included in the range, and further preferably 0.5%-10%.

[0021] In the present application, the mass percentage content of the additive is 0.2-15%, if its mass percentage content is too high, a uniformly dispersed dispersion liquid cannot be obtained due to solubility; if its mass percentage content is too low, it is difficult to play a role in improving the performance of the battery. At the same time, the mass percentage content of the additive is in the range of 0.2-15%, and as its mass percentage content increases, its safety performance gradually increases. Further, when the mass percentage content of the additive is preferably 0.5-10%, the battery obtained has better excellent electrochemical performance and safety performance and other comprehensive performance. When its mass percentage content is lower than the preferred range, the concentration in the electrolyte is low, and the role of the nitrogen-containing sulfur compound cannot be fully played; when its mass percentage content is higher than the preferred range, the viscosity of the electrolyte is large, the resistance increases, and the conductivity decreases, which is not conducive to the transport of lithium ions in the electrolyte.

[0022] Preferably, the electrolyte comprises any one of X'ClO4 (high chloride), X'PF6 (hexafluorophosphate), X'BF4 (tetrafluoroborate), X'TFSI (bis-trifluoromethylsulfonylimide), X'FSI (bis-fluorosulfonylimide), X'BOB (bis-oxalate borate), X'ODFB (difluoro-oxalate borate), X'SO3CF3 (trifluoromethanesulfonate), X'AsF6 (hexafluoroarsenate) or X'NO3 (nitrate), or a combination of at least two thereof, wherein X' is selected from any one of Li, Na or K.

[0023] Preferably, the electrolyte is present in an amount of 8-35% by mass, for example, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, or 35%, and specific point values between the foregoing are included, to the extent that the specific point values included in the range are not recited herein due to the length of this specification and in the interest of brevity.

[0024] Preferably, the organic solvent includes any one or a combination of at least two of carbonates, carboxylic acid esters, fluorinated carboxylic acid esters, propionic acid esters, fluoroether compounds, or aromatic hydrocarbons.

[0025] Preferably, the carbonates include halogenated carbonates and / or non-halogenated carbonates.

[0026] Preferably, the non-halogenated carbonates include any one or a combination of at least two of vinyl carbonate, propylene carbonate, diethyl carbonate, dimethyl carbonate, or methyl ethyl carbonate.

[0027] Preferably, the halogenated carbonates include any one or a combination of at least two of fluorinated vinyl carbonate, difluorinated vinyl carbonate, bisfluorinated propylene carbonate, trifluorinated ethyl acetate, trifluoroethyl methyl carbonate, trifluoromethyl vinyl carbonate, 4-trifluoromethyl vinyl carbonate, chlorinated vinyl carbonate, bis(2,2,2-trifluoroethyl) carbonate, trifluoropropionic acid methyl ester, 3,3,3-trifluorinated ethyl acetate, 2-trifluoromethyl benzoic acid methyl ester, 4,4,4-trifluorobutyric acid ethyl ester, or 1,1,1,3,3,3-hexafluoroisopropyl propenoic acid ester.

[0028] Preferably, the carboxylic acid esters include halogenated carboxylic acid esters and / or non-halogenated carboxylic acid esters.

[0029] Preferably, the non-halogenated carboxylic acid esters include any one or a combination of at least two of propyl butyrate, propyl acetate, isopropyl acetate, butyl propionate, isopropyl propionate, ethyl butyrate, methyl propionate, ethyl propionate, or propyl propionate.

[0030] Preferably, the halogenated carboxylic acid esters include any one or a combination of at least two of fluorinated propyl butyrate, fluorinated propyl acetate, fluorinated isopropyl acetate, fluorinated butyl propionate, fluorinated isopropyl propionate, fluorinated ethyl butyrate, fluorinated methyl propionate, fluorinated ethyl propionate, or fluorinated propyl propionate.

[0031] Preferably, the fluoroether compound has a number of carbon atoms ≤ 7, for example, 1, 2, 3, 4, 5, 6, or 7, and specific point values between the foregoing are included, to the extent that the specific point values included in the range are not recited herein due to the length of this specification and in the interest of brevity.

[0032] Preferably, the aromatic hydrocarbon includes halogenated aromatic hydrocarbon and / or non-halogenated aromatic hydrocarbon.

[0033] Preferably, the halogenated aromatic hydrocarbon includes any one or a combination of at least two of monofluorobenzene, difluorobenzene, 1,3,5-trifluorobenzene, trifluoromethylbenzene, 2-fluorotoluene or 2,4-dichlorotrifluorotoluene.

[0034] Preferably, the mass percentage of the organic solvent is 60-85% based on 100% of the mass percentage of the electrolyte, for example, can be 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82% or 85%, and specific point values between the above point values, limited to the length and for the sake of simplicity, the present application will not be listed in the range of specific point values included.

[0035] As a preferred technical solution of the present application, the electrolyte further comprises an additive.

[0036] Preferably, the additive includes any one or a combination of at least two of vinyl carbonate (VC), 1,3-propane sulfonate lactone (PS), tris(trimethylsilyl)borate (TMSB), propylene-1,3-sulfonate lactone (PST), methane disulfonate methylene (MMDS) or fluorinated ethylene carbonate (FEC).

[0037] Preferably, the mass percentage of the additive is 0.5-2% based on 100% of the mass percentage of the electrolyte, for example, can be 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8% or 2%, and specific point values between the above point values, limited to the length and for the sake of simplicity, the present application will not be listed in the range of specific point values included.

[0038] In the second aspect, the present application provides an energy storage device, and the battery includes the electrolyte containing nitrogen and sulfur atom compound according to the first aspect.

[0039] Preferably, the energy storage includes lithium ion battery, sodium ion battery, potassium ion battery or super capacitor.

[0040] Preferably, the negative electrode material of the lithium ion battery includes any one or a combination of at least two of graphite, soft carbon, hard carbon, single crystal silicon and graphite composite material, silicon monoxide and graphite composite material, lithium titanate or di-niobium pentoxide.

[0041] It should be noted that the preparation method of the lithium ion battery in the present application is not particularly limited, and the commonly used preparation methods in the art are applicable, including but not limited to the following preparation methods: the positive electrode uses a binder PVDF-S5130, a composite conductive agent Super-P / KS-6 (mass ratio Super-P:KS-6=2:1), an 811 nickel cobalt manganese ternary positive electrode material or a lithium cobaltate positive electrode material, and a solvent NMP (N-methyl-2-pyrrolidone), the negative electrode uses C-P15, a conductive agent Super-P solvent CMC, H2O, and a binder SBR as raw materials, and a slurry is prepared by using a wet slurry process respectively, the positive electrode is adjusted to a viscosity of 10000-13000 mPa·s, the negative electrode is adjusted to a viscosity of 1500-3000 mPa·s, the N / P ratio is designed to be 1.12, the capacity is 1.6-1.8 Ah, and then the lithium ion battery is prepared by coating, slicing, rolling, slitting, drying at 140℃ for 8h, pasting a tape, winding the battery core, drying at 80℃ for 48h, and then injecting and sealing the electrolyte according to the following different electrolyte formulations, standing for 24h, forming, primary final sealing, aging, secondary final sealing, to obtain a lithium ion soft package battery.

[0042] Compared with the prior art, the present application has at least the following beneficial effects:

[0043] (1) The present application introduces a nitrogen and sulfur atom-containing compound having a structure shown in formula I as an additive into the electrolyte by designing the composition of the electrolyte, so that the energy storage device composed of the electrolyte can obtain a lower internal resistance, while maintaining good first charge and discharge efficiency, high-rate discharge performance, low-temperature discharge characteristics and high-temperature storage performance, and significantly improves the cycle life and safety performance, and has excellent comprehensive performance.

[0044] (2) The lithium ion battery of the electrolyte of the nitrogen and sulfur atom-containing compound provided by the present application has a first charge and discharge efficiency of 86.3-87.3%, a DCIR internal resistance of 44.8-48.9 mΩ, a 3C discharge rate at room temperature of 79.4-84.7%, a 1C discharge rate at-20℃ of 80.2-83.9%, a cycle capacity retention rate of 86.9-90.8% for 800 cycles of 1C charge / 1C discharge at room temperature, a cycle capacity retention rate of 86.7-88.9% for 800 cycles of 1C charge / 1C discharge at 45℃, a capacity retention rate of 96.2-98.6% for storage at 55℃ for 7 days, a capacity recovery rate of 98.6-99.6%, and high safety. DETAILED DESCRIPTION

[0045] In order to facilitate the understanding of the present application, the present application lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present application and should not be regarded as a specific limitation on the present application.

[0046] The reagents and raw materials used in the following examples and comparative examples are commercially available unless otherwise specified. The nitrogen and sulfur atom-containing compound additives used in the examples and comparative examples are purchased from Shijiazhuang Shengtai Material Co., Ltd. (purity is greater than 99.8%). The structures of Formula II and Formula III are as follows:

[0047]

[0048] Examples 1-10 and Comparative Examples 1-5

[0049] Examples 1-10 and Comparative Examples 1-5 each provide an electrolyte, and the preparation method of the electrolyte includes the following steps:

[0050] The organic solvent is obtained by mixing ethylene carbonate (EC), methyl ethylene carbonate (EMC), and diethyl carbonate (DEC) in a mass ratio of 3:5:2, and then adding electrolyte, additives, and additive aids and mixing uniformly to obtain the electrolyte. The additive aid consists of 1% by mass of vinylene carbonate (VC) and 1% by mass of 1,3-propane sultone (PS). The electrolyte and the additives and the corresponding mass percentages are shown in Table 1, with the unit being “%”.

[0051] Table 1

[0052]

[0053] In the table, “-” represents that the component is not added.

[0054] The electrolytes described in Examples 1-10 and Comparative Examples 1-5 are assembled into soft-pack batteries for performance testing, wherein the negative electrode is graphite (Shanshan P15), and the positive electrode is NCM811 nickel-cobalt-manganese ternary. The battery used for testing has a nominal capacity of 1.80 Ah. The test standards / methods are as follows:

[0055] (1) First charge-discharge efficiency: After the battery is injected and left standing, it is charged at 0.02C for 2h, at 0.05C for 2h, and at 0.2C to 3.75V, then left standing for 24h of aging; then charged at 0.2C to 4.2V, and then charged at 4.2V constant voltage until the current drops to 0.02C cutoff, and the total capacity of the cumulative charge is recorded as A1. The capacity of the fully charged battery discharged at 0.2C to 2.75V is recorded as A2. A2 / A1 is the first charge-discharge efficiency.

[0056] (2) Internal resistance test: The battery is discharged at 3C (5.4A) current for 10s at 50% SOC, and the voltage change is recorded as ΔV. ΔV / 5.4A is the DCIR internal resistance.

[0057] (3) Discharge rate performance: 1C current is 1.8A, 3C current is 5.4A; the charge and discharge potential range is 2.75-4.2V. The discharge rate at normal temperature 25±1℃ of 3C is the ratio of the capacity C2 discharged by 3C constant current to the capacity C1 discharged by 1C constant current.

[0058] (4) Low-temperature discharge performance: the 1C (1.8A) discharge capacity at normal temperature 25±1℃ is recorded as C1, after full charging at 4.2V, the battery is frozen at-20℃ for 4h, then discharged to 2.75V at 1C (1.8A), the discharge capacity is recorded as C2. The discharge rate at-20±1℃ is C2 / C1.

[0059] (5) Cycle performance: the charge and discharge potential range is 2.75-4.2V, the charge current is 1C (1.8A) to 4.2V, the 4.2V constant voltage charging is stopped until the cutoff current is ≤0.02C (0.036A), after standing for 5min, the 1C (1.8A) discharging is to 2.75V, and standing for 5min; so the cycle charging and discharging.

[0060] (6) High-temperature storage performance: the 1C (1.8A) discharge capacity at normal temperature 25±1℃ is recorded as C1, after full charging at 4.2V, the battery is stored at 55±1℃ for 7 days, then discharged to 2.75V at 1C (1.8A) at 25±1℃, the discharge capacity is recorded as C2. After full charging at 25±1℃, the 1C (1.8A) discharging is to 2.75V, the discharge capacity is recorded as C3. C2 / C1 is the capacity retention rate, and C3 / C1 is the capacity recovery rate.

[0061] (7) Safety performance: the hot box test is that 10 batteries in full charge state are placed in an explosion-proof box at 130℃ for 30min; the needle puncture test is that 5 batteries in full charge state are punctured in the center of the battery with a 3mm steel needle at a speed of 10mm / s in an explosion-proof box.

[0062] The test results are shown in Tables 2-4.

[0063] Table 2

[0064]

[0065]

[0066] Table 3

[0067]

[0068] Table 4

[0069]

[0070]

[0071] From the test results, it can be seen that:

[0072] (1) From Examples 1 to 10, it can be seen that, when the additive of the nitrogen and sulfur atom-containing compound having the structure shown in Formula I is added to the electrolyte, the battery obtained has improved performance in various aspects, and has excellent comprehensive performance. The first charge-discharge efficiency is 86.3-87.3%, the DCIR internal resistance is 44.8-48.9 mΩ, the 3C discharge rate at room temperature is 79.4-84.7%, the 1C discharge rate at -20°C is 80.2-83.9%, the cycle capacity retention rate of 800 cycles of 1C charge / 1C discharge at room temperature is 86.9-90.8%, the cycle capacity retention rate of 800 cycles of 1C charge / 1C discharge at 45°C is 86.7-88.9%, the capacity retention rate after storage at 55°C for 7 days is 96.2-98.6%, the capacity recovery rate is 98.6-99.6%, and the safety is high.

[0073] (2) From Examples 1 to 8, it can be seen that, in the present application, as the mass percentage of the additive of the nitrogen and sulfur atom-containing compound in the electrolyte increases, the safety performance gradually increases. When the mass percentage reaches 10%, no fire or explosion occurs in the hot box test and the needle test, indicating that the electrolyte provided by the present application has high safety. Further, when the mass percentage is 0.5-10%, the comprehensive performance is better, indicating that by controlling the mass percentage of the additive of the nitrogen and sulfur atom-containing compound having the structure shown in Formula I, the present application can further improve the comprehensive performance of the obtained battery, especially the cycle performance, thereby improving the service life.

[0074] (3) From the comparison of Example 4 with Comparative Example 1 and Comparative Example 3, Example 5 with Comparative Example 4, and Example 1 with Comparative Example 5, it can be seen that the DCIR internal resistance of the batteries obtained in Comparative Example 1, Comparative Example 3, Comparative Example 4 and Comparative Example 5 is all higher than 50 mΩ, the cycle capacity retention rate of 800 cycles of 1C charge / 1C discharge at room temperature is at most 82.5%, the cycle capacity retention rate of 800 cycles of 1C charge / 1C discharge at 45°C is less than 80%, and the capacity retention rate after storage at 55°C for 7 days is at most 95.5%, indicating that compared with the prior art, the use of the additive of the nitrogen and sulfur atom-containing compound in the present application helps to reduce the internal resistance of the obtained battery, which can significantly improve the cycle life while maintaining good first charge-discharge efficiency, high-rate discharge performance, low-temperature discharge characteristics and high-temperature storage performance. Further, compared with Examples 1-10, the safety performance measured in Comparative Example 1, Comparative Example 3, Comparative Example 4 and Comparative Example 5 is significantly worse, indicating that the addition of the additive of the nitrogen and sulfur atom-containing compound to the electrolyte in the present application can significantly improve the safety of the obtained battery.

[0075] (4) By comparing Example 5 with Comparative Example 2, it can be seen that the battery obtained in Comparative Example 2, in which the additive of the nitrogen and sulfur atom-containing compound having the structure shown in Formula I is not added to the electrolyte, has obviously poorer comprehensive performance, especially the resistance is significantly higher, and the normal temperature or high temperature cycle performance and safety performance are significantly deteriorated, indicating that by adding the additive of the nitrogen and sulfur atom-containing compound having the structure shown in Formula I to the electrolyte, the cycle life and safety of the obtained battery can be obviously improved, and the comprehensive performance is excellent.

[0076] In summary, by designing the composition of the electrolyte and introducing the nitrogen and sulfur atom-containing compound having the structure shown in Formula I as an additive into the electrolyte, the energy storage device composed of the electrolyte can obtain a lower internal resistance, and at the same time, the cycle life and safety performance are obviously improved while maintaining good first charge-discharge efficiency, high-rate discharge performance, low-temperature discharge characteristics and high-temperature storage performance, and the comprehensive performance is excellent.

[0077] The above merely describes the specific embodiments of the present application, but the protection scope of the present application is not limited thereto. It should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the present application can be easily conceived by those skilled in the art, and all such changes or replacements fall within the protection scope and disclosure scope of the present application.

Claims

1. An electrolyte solution of a nitrogen-sulfur atomized compound, characterized by, The electrolyte comprises an electrolyte, an organic solvent and an additive; the additive comprises a nitrogen and sulfur atom-containing compound with a structure shown in Formula I: R1 is selected from substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C2-C6 alkenyl, substituted or unsubstituted C2-C6 alkynyl, substituted or unsubstituted C6-C20 aryl; R2 is selected from halogen, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C2-C6 alkenyl, substituted or unsubstituted C2-C6 alkynyl, substituted or unsubstituted C6-C20 aryl; X is selected from alkali metals; The substituted substituent is selected from at least one of fluorine, C1-C4 alkyl, C1-C4 alkoxy or C2-C4 alkenyl.

2. The electrolyte solution of the nitrogen-sulfur atom-containing compound according to claim 1, characterized by, R1 is selected from any one of methyl, ethyl or fluorine-substituted C1-C2 alkyl; R2 is selected from any one of F, methyl, ethyl or fluorine-substituted C1-C2 alkyl; X is any one of Li, Na or K.

3. The electrolyte solution of the nitrogen-sulfur atom-containing compound according to claim 1 or 2, characterized by, The mass percentage of the additive is 0.2-15% based on 100% of the mass percentage of the electrolyte.

4. The electrolyte solution of the nitrogen-sulfur atom-containing compound according to claim 3, characterized by, The mass percentage of the additive is 0.5-10% based on 100% of the mass percentage of the electrolyte.

5. The electrolyte solution of the nitrogen-sulfur atom-containing compound according to any one of claims 1 to 4, characterized by, The electrolyte comprises any one of X'ClO4, X'PF6, X'BF4, X'TFSI, X'FSI, X'BOB, X'ODFB, X'SO3CF3, X'AsF6 or X'NO3 or a combination of at least two thereof, wherein X' is selected from any one of Li, Na or K.

6. The electrolyte solution of the nitrogen-sulfur atom-containing compound according to any one of claims 1 to 5, characterized by, The mass percentage of the electrolyte is 8-35% based on 100% of the mass percentage of the electrolyte.

7. The electrolyte solution of the nitrogen-sulfur atom-containing compound according to any one of claims 1 to 6, characterized by, The organic solvent comprises any one of carbonates, carboxylic acid esters, fluorinated carboxylic acid esters, propionic acid esters, fluorinated ethers or aromatic hydrocarbons or a combination of at least two thereof.

8. The electrolyte solution of the nitrogen-sulfur atom-containing compound according to any one of claims 1 to 7, characterized by, The mass percentage of the organic solvent is 60-85% based on 100% of the mass percentage of the electrolyte.

9. An energy storage device, characterized by, The energy storage device comprises the electrolyte of the nitrogen and sulfur atom-containing compound according to any one of claims 1-8.

10. The energy storage device of claim 9, wherein, The energy storage device comprises a lithium ion battery, a sodium ion battery, a potassium ion battery or a supercapacitor. Preferably, the negative electrode material of the lithium ion battery comprises any one of graphite, soft carbon, hard carbon, a composite of single-crystal silicon and graphite, a composite of silicon monoxide and graphite, lithium titanate or di-niobium pentoxide or a combination of at least two thereof.

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