Electrolyte, battery, and electric device
By using an electrolyte containing a first additive in a sodium-ion battery, a low-resistance, dense SEI film is formed, solving the problem of poor SEI film stability and improving the battery's cycle performance and lifespan.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- BYD CO LTD
- Filing Date
- 2025-12-23
- Publication Date
- 2026-07-02
AI Technical Summary
The SEI film in existing sodium-ion batteries has poor stability, resulting in poor battery cycle performance and affecting its long-term use.
An electrolyte containing a first additive is used to promote the formation of a low-impedance, dense and stable SEI film. By using a compound with the general chemical formula (1) and other additives, the migration kinetics of sodium ions are improved, the contact between the electrolyte and the electrode is suppressed, and side reactions are reduced.
It significantly improves the room temperature cycling performance and other performance characteristics of sodium-ion batteries, extends battery life, reduces system impedance, and promotes the full utilization of the positive and negative electrode capacity.
Smart Images
Figure CN2025144573_02072026_PF_FP_ABST
Abstract
Description
Electrolytes, batteries and electrical equipment
[0001] Priority information
[0002] This application claims priority and benefits to patent application No. 202411948969.1, filed with the China National Intellectual Property Administration on December 26, 2024, the entire contents of which are incorporated herein by reference. Technical Field
[0003] This disclosure relates to the field of battery technology, and in particular to an electrolyte, a battery, and an electrical device. Background Technology
[0004] In related technologies, the key to improving the cycle performance of sodium-ion batteries lies in the construction of a low-impedance, high-toughness solid electrolyte interphase (SEI) membrane. An effective SEI membrane can significantly reduce system impedance, exhibit high sodium-ion migration kinetics, promote the full utilization of the positive and negative electrode capacities, and simultaneously suppress side reactions between the electrolyte and the electrode plates, thereby achieving a comprehensive improvement in the cycle performance and even the overall performance of sodium-ion batteries. However, the SEI membrane in sodium-ion batteries using conventional electrolytes has poor stability, which is detrimental to the long-term stable use of sodium-ion batteries.
[0005] Public content
[0006] This disclosure aims to at least address one of the technical problems existing in the prior art. To this end, one object of this disclosure is to provide an electrolyte employing a first additive that can promote the formation of a low-resistance, dense, and stable SEI film, thereby promoting the stable performance of the negative electrode capacity of the battery.
[0007] Another object of this disclosure is to provide a battery using the above-described electrolyte.
[0008] Another object of this disclosure is to provide an electrical device using the aforementioned battery.
[0009] According to an embodiment of the first aspect of this disclosure, the electrolyte includes a first additive, the first additive comprising a compound having the general chemical formula (1):
[0010] In formula (1), R1 and R2 are independently selected from hydrogen atoms, halogen atoms, C1-C10 alkyl groups, C1-C10 alkoxy groups, C2-C10 carboxylic acid ester groups, C2-C10 carbonate groups, C1-C10 fluoro or brominated alkyl groups, C1-C10 fluoro or brominated alkoxy groups, C2-C10 fluoro or brominated carboxylic acid ester groups or C2-C10 fluoro or brominated carbonate groups or groups having the chemical structure shown in general formula (2):
[0011] In equation (2), n is a natural number greater than or equal to 0.
[0012] According to the electrolyte of this disclosure, by using an electrolyte containing a first additive, it is possible to promote the formation of a low-resistance and dense SEI film at the positive and negative electrodes. The SEI film has a high sodium ion migration kinetics, which promotes the capacity utilization of the positive and negative electrodes. At the same time, it can effectively isolate the contact between the electrolyte and the electrode, suppress the occurrence of side reactions, thereby significantly improving the room temperature cycle performance of the sodium-ion battery and other performance characteristics.
[0013] According to some embodiments of this disclosure, the electrolyte further includes a second additive, the second additive comprising at least one of tris(trimethylsilane) phosphate, tris(trimethylsilyl) phosphite, and tris(trimethylsilane) borate.
[0014] According to some embodiments of this disclosure, the content of the first additive is 0.1% to 10% by mass percentage; and / or, the content of the second additive is 0.1% to 10% by mass percentage.
[0015] According to some embodiments of this disclosure, R1 and R2 are independently selected from groups having the general chemical formula (2):
[0016] In equation (2), n is a natural number greater than or equal to 0.
[0017] According to some embodiments of this disclosure, the electrolyte further includes 5 wt% to 45 wt% of sodium salt and 45 wt% to 94.7 wt% of solvent.
[0018] According to some embodiments of this disclosure, the sodium salt includes at least one of sodium hexafluorophosphate, sodium perchlorate, sodium bis(trifluoromethanesulfonyl)imide, sodium bis(fluorosulfonyl)imide, sodium trifluoromethanesulfonate, sodium difluorooxalateborate, sodium bis(oxalateborate), sodium hexafluoroarsenate, sodium tetrafluoroborate, sodium nitrate, and sodium chloride.
[0019] According to some embodiments of this disclosure, the solvent includes at least one selected from ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, 1,3-dioxolane, methyl acetate, ethyl propionate, propyl propionate, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, N,N-dimethylformamide, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, and bis(2,2,2-trifluoroethyl) ether.
[0020] According to some embodiments of this disclosure, the electrolyte further includes a third additive, said third additive comprising at least one selected from fluoroethylene carbonate, vinylene carbonate, 1,3-propane sulpholactone, propylene sulfate, propylene-1,3-sulfonyl lactone, ethylene sulfate, methanedisulfonate, succinate, adiponitrile, trimethyl phosphate, triphenyl phosphate, trifluoromethylsilane, ethoxy(pentafluoro)cyclotriphosphazene, and biphenyl.
[0021] According to some embodiments of this disclosure, the content of the third additive is 0.1% to 10% by mass percentage.
[0022] The battery according to a second aspect embodiment of the present disclosure includes the electrolyte described in the first aspect embodiment above.
[0023] According to some embodiments of this disclosure, the battery includes a sodium-ion battery.
[0024] The electrical device according to a third aspect of the present disclosure includes the battery described in the second aspect of the present disclosure.
[0025] Additional aspects and advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description
[0026] The above and / or additional aspects and advantages of this disclosure will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0027] Figure 1 is a performance comparison chart of the batteries in Example 1 and Example 2 prepared according to the electrolyte of this disclosure;
[0028] Figure 2 is a performance comparison chart of the batteries in Example 1 and Example 3 prepared according to the electrolyte of this disclosure;
[0029] Figure 3 is a performance comparison chart of the batteries prepared according to the electrolyte of this disclosure in Examples 1, 3 and 4;
[0030] Figure 4 is a performance comparison chart of the batteries in Examples 2 and 5 prepared according to the electrolyte of this disclosure;
[0031] Figure 5 is a performance comparison chart of the batteries prepared according to the electrolyte of this disclosure in Examples 2 and 6-8;
[0032] Figure 6 is a performance comparison chart of the batteries prepared according to the electrolyte of this disclosure in Examples 6, 9 and 10;
[0033] Figure 7 is a compositional analysis diagram of the negative electrode SEI film of the battery prepared according to the electrolyte in Example 2 of this disclosure.
[0034] Figure 8 is a compositional analysis diagram of the positive electrode CEI film of the battery prepared according to the electrolyte in Example 2 of this disclosure.
[0035] Detailed description
[0036] The embodiments of this disclosure are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The electrolyte according to the first aspect of this disclosure is described below with reference to Figures 1-3. In the following description of this application, the electrolyte used in a sodium-ion battery is used as an example.
[0037] According to the electrolyte of the first aspect of this disclosure, the electrolyte includes a first additive, the first additive including a compound having the general chemical formula (1):
[0038] In formula (1), R1 and R2 are independently selected from hydrogen atoms, halogen atoms, C1-C10 alkyl groups, C1-C10 alkoxy groups, C2-C10 carboxylic acid ester groups, C2-C10 carbonate groups, C1-C10 fluoro or brominated alkyl groups, C1-C10 fluoro or brominated alkoxy groups, C2-C10 fluoro or brominated carboxylic acid ester groups or C2-C10 fluoro or brominated carbonate groups or groups having the chemical structure shown in general formula (2):
[0039] In equation (2), n is a natural number greater than or equal to 0.
[0040] In other words, R1 and R2 in equation (1) can be the same group or different groups. n can be a natural number such as 0, 1, 2, ... For example, R 1、 When R2 is independently selected from a halogenated group, it can generate more sodium halide inorganic substances during SEI film formation, improving the stability of the SEI film. Using an electrolyte with a first additive can promote the formation of a low-resistance and dense SEI film at both the positive and negative electrodes. The SEI film has high sodium ion migration kinetics, promoting the full utilization of the positive and negative electrode capacities. Simultaneously, it can effectively isolate the electrolyte from the electrode, suppressing side reactions, thereby significantly improving the room-temperature cycle performance of sodium-ion batteries and enhancing other performance characteristics. An effective SEI film can significantly reduce system impedance, possess high sodium ion migration kinetics, promote the full utilization of the positive and negative electrode capacities, and effectively isolate the electrolyte from the electrode, suppressing side reactions, thus achieving a comprehensive improvement in the cycle performance and even the overall performance of sodium-ion batteries.
[0041] According to the electrolyte of this disclosure, by using an electrolyte containing a first additive, it is possible to promote the formation of a low-resistance and dense SEI film at the positive and negative electrodes. The SEI film has a high sodium ion migration kinetics, which promotes the capacity utilization of the positive and negative electrodes. At the same time, it can effectively isolate the contact between the electrolyte and the electrode, suppress the occurrence of side reactions, thereby significantly improving the room temperature cycle performance of the sodium-ion battery and other performance characteristics.
[0042] According to some embodiments of this disclosure, the electrolyte further includes a second additive, which includes at least one of tris(trimethylsilane) phosphate (TMSP), tris(trimethylsilyl) phosphite (TMSPi), and tris(trimethylsilane) borate (TMSB).
[0043] For example, the second additive is a dehydrating or HF-removing additive. When R1 and R2 are independently selected from silicon-free groups, the combined use of the first and second additives can promote the formation of compounds containing Na2SO4 / ROSO3Na (mainly), Na2SO3 / ROSO2Na, or Na2S / Na. x The low impedance, dense and stable SEI film composed of S and other components promotes the stable performance of the negative electrode capacity and suppresses the occurrence of side reactions between the electrode sheet and the electrolyte, thereby achieving ultra-long stable cycling.
[0044] According to some embodiments of this disclosure, the content of the first additive is 0.1% to 10% by mass percentage; and / or, the content of the second additive is 0.1% to 10% by mass percentage. That is, when the electrolyte includes a first electrolyte, the content of the first electrolyte is 0.1% to 10%. When the electrolyte includes a first electrolyte and a second electrolyte, the contents of the first electrolyte and the second electrolyte are respectively 0.1% to 10%. This setting is reasonable for the content of the first and second additives. Combined with the experimental results of the embodiments described below (Table 1), it can be seen that when the content of the first additive is between 0.1% and 10%, the electrolyte has better performance, which is beneficial to the performance of the electrolyte and thus beneficial to its use. Furthermore, it can also reduce the amount of electrolyte added, reducing costs. When the contents of the first additive and the second additive are respectively between 0.1% and 10%, the performance of the electrolyte is further improved, thus making the use of the electrolyte even more beneficial.
[0045] According to some embodiments of this disclosure, R1 and R2 are independently selected from groups having the general chemical formula (2):
[0046] In equation (2), n is a natural number greater than or equal to 0.
[0047] For example, when n equals 0, the structural formula of the first additive is as follows:
[0048] When the first additive has the above-mentioned chemical structure, the electrolyte performance is superior. When both R1 and R2 are silane substituents, on the one hand, the silane group can effectively remove H2O and HF, improving the density of the SEI film; on the other hand, it synergistically forms a more stable SEI film with the sulfonic acid group, especially stabilizing the positive electrode CEI film. Combined with the results in Table 1, it can be seen that the sodium-ion battery using this electrolyte exhibits high capacity retention after 500 cycles, significantly suppressing the side reactions caused by contact between the electrode plates and the electrolyte in the sodium-ion battery.
[0049] According to some embodiments of this disclosure, the electrolyte further includes 5 wt%-45 wt% sodium salt and 45 wt%-94.7 wt% solvent (or the balance being solvent). The sodium salt has a mass percentage of 4-45%. The sodium salt includes at least one of sodium hexafluorophosphate, sodium perchlorate, sodium bis(trifluoromethanesulfonyl)imide, sodium bis(fluorosulfonyl)imide, sodium trifluoromethanesulfonate, sodium difluorooxalateborate, sodium bis(oxalateborate), sodium hexafluoroarsenate, sodium tetrafluoroborate, sodium nitrate, and sodium chloride.
[0050] For example, the concentration of sodium salt is 0.5 mol / L to 5 mol / L. This setting, using the aforementioned sodium salt to prepare the electrolyte, is beneficial for the use of the electrolyte and for maximizing its performance. Furthermore, sodium-ion batteries made using the electrolyte of this application have advantages such as lower cost, excellent cycle performance, good high and low temperature performance, and safety, which are conducive to the long-term use of sodium-ion batteries. In addition, the aforementioned sodium salt is widely available and easily purchased, thus facilitating the preparation of the electrolyte.
[0051] According to some embodiments of this disclosure, the solvent includes at least one selected from ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, 1,3-dioxolane, methyl acetate, ethyl propionate, propyl propionate, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, N,N-dimethylformamide, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, and bis(2,2,2-trifluoroethyl) ether. Therefore, using the above-mentioned solvents facilitates the dissolution of sodium salts, the first additive, and the second additive, thereby facilitating the preparation of the electrolyte and simplifying the operation. Furthermore, the dissolution rate is fast and the dissolution effect is good. In addition, the use of the above-mentioned solvents has no effect on the performance of the electrolyte, which is beneficial to the performance of the electrolyte.
[0052] According to some embodiments of this disclosure, the electrolyte further includes a third additive, which includes at least one selected from fluoroethylene carbonate, vinylene carbonate, 1,3-propane sulpholactone, propylene sulfate, propylene-1,3-sulfonyl lactone, ethylene sulfate, methanedisulfonate, succinate, adiponitrile, trimethyl phosphate, triphenyl phosphate, trifluoromethylsilane, ethoxy(pentafluoro)cyclotriphosphazene, and biphenyl.
[0053] In other words, depending on the application requirements of the electrolyte, other film-forming additives, flame-retardant additives, and overcharge protection additives can also be included. In other words, different types of additives can be added according to the different application scenarios of sodium-ion batteries. For example, adding 1,3-propanesulfonyl lactone and fluoroethylene carbonate can improve the battery's high-temperature cycle stability; adding biphenyl additives can improve the battery's overcharge protection performance; adding phosphorus-containing additives such as trimethyl phosphate and triphenyl phosphate can improve battery safety performance, and so on. Furthermore, the materials for the aforementioned third additives are readily available, which is beneficial for electrolyte preparation.
[0054] According to some embodiments of this disclosure, the content of the third additive is 0.1% to 10% by mass percentage. In other words, the mass percentage of the third additive is w, where w satisfies: 0.1% ≤ w ≤ 10%. This setting ensures a reasonable amount of the third additive. When the electrolyte includes multiple components such as the first additive, second additive, third additive, sodium salt, and solvent, the synergistic effect of these components can comprehensively improve battery performance, thus benefiting battery use.
[0055] A battery according to a second aspect embodiment of the present disclosure, such as a sodium-ion battery, includes the electrolyte according to the first aspect embodiment described above.
[0056] According to the battery of the second aspect of this disclosure, by using the above-described electrolyte, the room temperature cycle performance of the sodium-ion battery can be significantly improved, as well as other performance characteristics of the sodium-ion battery, which is beneficial for the long-term use of the sodium-ion battery. For example, including a sodium-ion battery in the battery is beneficial for maximizing the performance of the sodium-ion battery.
[0057] The electrical device according to a third aspect of the present disclosure includes a battery according to the second aspect of the present disclosure.
[0058] According to the third aspect of this disclosure, the electrical equipment using the aforementioned battery improves its performance. Examples of such electrical equipment include vehicles, aircraft, ships, computers, energy storage cabinets, etc.
[0059] The embodiments of this disclosure are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain this disclosure, and should not be construed as limiting this disclosure. In addition, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known to others. For reaction conditions not listed, they are also readily available to those skilled in the art.
[0060] The electrolyte and battery of this disclosure are illustrated through exemplary embodiments and comparative examples. The performance of the batteries of Examples 1-10 and Comparative Examples 1-3 is tested below.
[0061] The calculation method for capacity division and first-efficiency is as follows: At room temperature, the fresh battery is charged to 3.6V at a constant current and constant voltage of 1C, and the cutoff current is 0.05C. The formation charging capacity is recorded. After standing for 10 minutes, the battery is discharged to 1.5V at a constant current of 1C. The capacity division discharge capacity is recorded.
[0062] The initial efficiency is calculated using the following formula: Initial efficiency = Discharge capacity / Formation charge capacity.
[0063] Battery cycle performance test: The battery is charged and discharged at a current density of 1C, the test voltage range is 1.5 to 3.6V, and the test temperature is 25℃.
[0064] The capacity retention rate is calculated using the following formula: Current cycle capacity retention rate = Current cycle discharge capacity / First cycle discharge capacity.
[0065] Example 1
[0066] (1) Preparation of electrolyte
[0067] First, propylene carbonate (PC), ethylene carbonate (EC), and diethyl carbonate (DEC) were mixed in a mass ratio of 20:10:70 to prepare a mixed solvent. The water in the mixed solvent was removed using a molecular sieve. 1 mol / L sodium hexafluorophosphate was added in batches to the dry and anhydrous mixed solvent while stirring. After cooling, 2 wt% of [4,4'-bis(1,3,2-dioxothionane)]2,2,2',2'-tetraoxide (BDTT) was added as the first additive to finally obtain a clear, colorless, and transparent electrolyte for sodium-ion batteries.
[0068] Among them, the above BDTT is the compound in formula (1) when R1 and R2 are both selected from hydrogen atoms.
[0069] (2) Preparation of positive electrode
[0070] A positive electrode material, such as sodium iron phosphate pyrophosphate (NFPP), a binder, such as polyvinylidene fluoride (PVDF), and a conductive agent, such as acetylene black (SuperP), are mixed in a mass ratio of 8:1:1, and a certain amount of N-methylpyrrolidone (NMP) is added to make a positive electrode slurry. The solid content of the slurry is adjusted to about 50%. After degassing and sieving, the slurry is uniformly coated on the surface of aluminum foil. After drying, rolling, and cutting, a positive electrode sheet is obtained.
[0071] (3) Preparation of negative electrode
[0072] The negative electrode material hard carbon (HC), the composite binder styrene-butadiene rubber (SBR) / carboxymethyl cellulose (CMC) and the conductive agent acetylene black (SuperP) are mixed in a mass ratio of 8:1:1, and deionized water is added to prepare the negative electrode slurry. The solid content is adjusted to about 45%, and after degassing and sieving, it is uniformly coated on the surface of aluminum foil. After drying, rolling and cutting, the negative electrode sheet is obtained.
[0073] (4) Battery manufacturing
[0074] The negative electrode, separator, and positive electrode are stacked in sequence to form a cell, which is then packaged in an aluminum-plastic shell. After the cell is baked to remove moisture, the electrolyte prepared in (1) is injected into the soft-pack battery. After aging, formation, and capacity testing, a soft-pack sodium-ion battery is obtained.
[0075] (5) Performance Testing
[0076] Examples 2-5
[0077] The main difference from Example 1 is the different additives (i.e., whether to add a second and third additive, and the choice of the type and amount of additives), as shown in Table 1.
[0078] Example 6
[0079] The main difference from Example 2 is the different sodium salt.
[0080] Example 7
[0081] The main difference from Example 2 is the different solvent and sodium salt.
[0082] Example 8
[0083] The main difference from Example 7 is the different solvent.
[0084] Example 9
[0085] The main difference from Example 2 is that the content of the first additive is different.
[0086] Example 10
[0087] The main difference from Example 2 is that the content of the first additive is different.
[0088] Comparative Examples 1-3
[0089] The main difference from Example 3 is the different additives. That is, the electrolyte does not include the first additive. Information on the specific additives is shown in Table 1.
[0090] The charging performance of the batteries prepared in Examples 1-10 and Comparative Examples 1-3 was measured, and the results are shown in Table 1.
[0091] Table 1
[0092] It should be noted that BTMSBDTD refers to 6-[2,2-dioxane-5-(trimethylsilyl)-2λ6-1,3,2-dioxane-4-yl]-4-(trimethylsilyl)-2λ6-1,3,2-dioxane-2,2-dione, that is, the compound in formula (1) where R1 and R2 are both selected from silane groups. FEC refers to fluoroethylene carbonate (third additive). DEGDME refers to diethylene glycol dimethyl ether. TFE refers to 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether. DTD refers to vinyl sulfate.
[0093] Referring to Figures 1-6 and the data from Examples 1-8 in Table 1, it can be seen that the battery prepared using the electrolyte containing the first additive exhibits a high capacity retention rate after 500 cycles at 1C room temperature. According to Examples 1 and 3, the battery prepared in Example 3 shows a higher capacity retention rate after 500 cycles at room temperature, indicating superior performance. Comparing Examples 1, 2, and Comparative Example 1, it is evident that the capacity retention rate after 500 cycles at room temperature is significantly reduced when the electrolyte without the first additive is used, resulting in decreased battery performance. Comparing Examples 1 and 3, it is evident that when the first additive does not contain silane groups, and is used in conjunction with a TMSP additive containing silane groups, the battery exhibits a higher capacity retention rate after 500 cycles at room temperature, indicating superior performance. Comparing Examples 1 and Comparative Example 1, and Examples 3 and Comparative Example 2, it is evident that when BDTT of this application is used as the first additive, the capacity retention rate after 500 cycles at 1C room temperature is significantly increased. Comparing Comparative Example 3 and Example 4, it is evident that the capacity retention rate of the electrolyte without the first additive is significantly reduced after 500 cycles at room temperature, resulting in decreased battery performance. Compared to Example 3, Example 4 shows a decrease in capacity retention rate after 500 cycles at 1C room temperature with the addition of the third additive, FEC. This is because FEC increases battery impedance, generally leading to a decrease in room temperature cycle capacity retention. Therefore, the third additive can be added as needed to improve overall battery performance. For example, while adding FEC may reduce capacity retention rate after 600 cycles at 1C room temperature, it can improve the high-temperature performance of the electrolyte, thus enhancing overall battery performance.
[0094] SEI membrane characterization
[0095] Referring to Figures 7 and 8, due to the presence of sulfate groups, BTMSBDTD as the first additive promotes the formation of an SEI film containing more Na2SO4 / ROSO3Na, Na2SO4 / ROSO3Na, and Na2S on the negative electrode side, and an CEI film containing more Na2SO4 / ROSO3Na and Na2SO4 / ROSO3Na on the positive electrode side. Simultaneously, the presence of trimethylsilyl groups promotes the formation of more inorganic C3H9Si products on the positive electrode side, and trimethylsilyl groups also remove H2O and HF, promoting the densification of the SEI film. Considering all these factors, BTMSBDTD as the first additive promotes the formation of stable negative electrode SEI films and positive electrode CEI films, ensuring sufficient and stable negative electrode capacity, suppressing continuous side reactions between the electrode and the electrolyte, and thus achieving stable cycle performance.
[0096] The sodium-ion battery, other components of the electrical equipment, and operation according to the embodiments of this disclosure are known to those skilled in the art and will not be described in detail here.
[0097] In the description of this disclosure, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure.
[0098] In the description of this disclosure, "multiple" means two or more.
[0099] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.
[0100] Although embodiments of this disclosure have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this disclosure, the scope of which is defined by the claims and their equivalents.
Claims
1. An electrolyte, wherein, The first additive includes a compound having the general chemical formula (1): In formula (1), R1 and R2 are independently selected from hydrogen atoms, halogen atoms, C1-C10 alkyl groups, C1-C10 alkoxy groups, C2-C10 carboxylic acid ester groups, C2-C10 carbonate groups, C1-C10 fluoro or brominated alkyl groups, C1-C10 fluoro or brominated alkoxy groups, C2-C10 fluoro or brominated carboxylic acid ester groups or C2-C10 fluoro or brominated carbonate groups or groups having the chemical structure shown in general formula (2): In equation (2), n is a natural number greater than or equal to 0.
2. The electrolyte according to claim 1, wherein, The product also includes a second additive by weight percentage, the second additive comprising at least one of tris(trimethylsilane) phosphate, tris(trimethylsilyl) phosphite and tris(trimethylsilane) borate.
3. The electrolyte according to claim 2, wherein, The content of the first additive is 0.1% to 10% by mass percentage; and / or, The content of the second additive is 0.1% to 10% by mass percentage.
4. The electrolyte according to any one of claims 1 to 3, wherein, R1 and R2 are independently selected from groups having the general chemical formula (2): In equation (2), n is a natural number greater than or equal to 0.
5. The electrolyte according to any one of claims 1 to 4, wherein, It also includes 5wt%-45wt% sodium salt and 45wt%-94.7wt% solvent.
6. The electrolyte according to claim 5, wherein, The sodium salt includes at least one of sodium hexafluorophosphate, sodium perchlorate, sodium bis(trifluoromethanesulfonyl)imide, sodium bis(fluorosulfonyl)imide, sodium trifluoromethanesulfonate, sodium difluorooxalateborate, sodium bis(oxalateborate), sodium hexafluoroarsenate, sodium tetrafluoroborate, sodium nitrate, and sodium chloride.
7. The electrolyte according to claim 5, wherein, The solvent includes at least one selected from ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, 1,3-dioxolane, methyl acetate, ethyl propionate, propyl propionate, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, N,N-dimethylformamide, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, and bis(2,2,2-trifluoroethyl) ether.
8. The electrolyte according to any one of claims 1 to 7, wherein, Also includes: The third additive includes at least one selected from fluoroethylene carbonate, vinylene carbonate, 1,3-propane sulpholactone, propylene sulfate, propylene-1,3-sulfonyl lactone, vinyl sulfate, methanedisulfonate, succinate, adiponitrile, trimethyl phosphate, triphenyl phosphate, trifluoromethylsilane, ethoxy(pentafluoro)cyclotriphosphazene, and biphenyl.
9. The electrolyte according to claim 8, wherein, The content of the third additive is 0.1% to 10% by mass percentage.
10. A battery, wherein, Includes the electrolyte according to any one of claims 1 to 9.
11. The battery according to claim 10, wherein, The battery includes a sodium-ion battery.
12. An electrical appliance, wherein, Includes the battery according to claim 10 or 11.