Electrolyte additive, electrolyte, battery and electrical device

Abstract

Electrolyte additive for a battery with a silicon-based negative electrode, wherein the electrolyte additive comprises the following: a first additive, wherein the first additive comprises tetravinylsilane and tris[ethenyl(dimethyl)silyl]phosphate; and a first lithium salt, wherein the first lithium salt comprises lithium tetrafluoro(oxalato)phosphate.

Description

[0001] The application claims priority over Chinese patent application No. 202311637451.1 entitled “ELECTROLYTE ADDITIVE, ELECTROLYTE, BATTERY, AND ELECTRIC DEVICE”, filed with the Chinese National Administration of Intellectual Property on December 1, 2023, the entire contents of which are incorporated herein by reference. TECHNICAL AREA

[0002] The present disclosure relates to the field of electrolytes and in particular to an electrolyte additive, an electrolyte, a battery and an electrical device. BACKGROUND

[0003] Against the backdrop of increasing attention to the depletion of non-renewable energy sources and problems related to environmental pollution, renewable, clean energy carriers have rapidly developed. Due to advantages such as high specific energy, long service life, and low self-discharge, lithium-ion batteries are widely used in consumer electronics, energy storage, and traction batteries. A typical battery includes a positive electrode plate, a negative electrode plate, an electrolyte, and a separator. The electrolyte in a lithium-ion battery consists of a solvent, a lithium salt electrolyte, and an electrolyte additive. Adding the electrolyte additive can effectively improve cycle life, performance after high-temperature storage, and other battery characteristics.However, conventional electrolyte additives still face certain problems in practical applications.

[0004] It should be noted that the foregoing statements are intended to provide only technical background information in connection with the present disclosure and do not necessarily reflect the state of the art. SUMMARY

[0005] In a first aspect of the present disclosure, an electrolyte additive for a battery with a silicon-based negative electrode is provided. The electrolyte additive comprises a first additive and a first lithium salt. The first additive comprises tetravinylsilane and tris[ethenyl(dimethyl)silyl]phosphate. The first lithium salt comprises lithium tetrafluoro(oxalato)phosphate. Thus, the electrolyte containing the electrolyte additive can improve the cycle life and high-temperature performance of the battery.

[0006] In some embodiments, the electrolyte additive contains a mass fraction of tetravinylsilane (a) and a mass fraction of lithium tetrafluoro(oxalato)phosphate (b), where a / b ranges from 0.05 to 20. This improves the cycle life of the battery containing the electrolyte additive.

[0007] In some embodiments, the electrolyte additive contains a mass fraction of lithium tetrafluoro(oxalato)phosphate (b) and a mass fraction of tris[ethenyl(dimethyl)silyl]phosphate (c), where b / c ranges from 0.05 to 20. This allows for improved performance after high-temperature storage of the battery containing the electrolyte additive.

[0008] In some embodiments, the electrolyte additive further includes a second additive. This second additive comprises at least one high-temperature additive, a film-forming additive for negative electrodes, a lithium salt additive, or a water / acid scavenger additive. This allows for improvements in the rated power, high-temperature performance, and lifespan of the battery containing the electrolyte additive.

[0009] In some embodiments, the second additive meets at least one of the following conditions: the high-temperature additive includes at least one of 1,3-propanesultone, ethylene sulfate, or ethylene sulfite; the film-forming additive for negative electrodes includes at least one of vinylene carbonate, fluoroethylene carbonate, or vinylethylene carbonate; the lithium salt additive includes at least one of lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium difluorobis(oxalato)phosphate, lithium tetrafluoroborate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(pentafluoroethanesulfonyl)imide, lithium trifluoromethanesulfonate, or lithium difluorophosphate; or the water / acid scavenger additive includes at least one of tris(trimethylsilyl)borate or tris(trimethylsilyl)phosphate. Thus, the rated performance, high-temperature performance, and lifetime of the battery containing the electrolyte additive can be further improved.

[0010] In a second aspect of the present disclosure, an electrolyte is provided. The electrolyte includes the electrolyte additive described above. Consequently, the electrolyte exhibits all the features and advantages of the electrolyte additive described above, which are not described in detail herein.

[0011] In some embodiments, the electrolyte further comprises a solvent and an electrolyte lithium salt. The electrolyte lithium salt contains at least one of lithium hexafluorophosphate or lithium bis(fluorosulfonyl)imide. Consequently, the ionic conductivity and long-term stability of the electrolyte can be improved.

[0012] In some embodiments, the mass fraction of the electrolyte lithium salt in the electrolyte ranges from 12% to 18%. Consequently, the ionic conductivity of the electrolyte can be further improved.

[0013] In some embodiments, a mass fraction of tetravinylsilane in the electrolyte ranges from 0.1% to 2%. Consequently, the cycle performance of the battery containing the electrolyte can be improved.

[0014] In some embodiments, a mass fraction of lithium tetrafluoro(oxalato)phosphate in the electrolyte ranges from 0.1% to 2%. Consequently, the cycle performance of the battery containing the electrolyte can be improved.

[0015] In some embodiments, the mass fraction of tris[ethenyl(dimethyl)silyl]phosphate in the electrolyte ranges from 0.1% to 2%. Consequently, the performance of the battery containing the electrolyte can be improved after high-temperature storage.

[0016] In some embodiments, the mass fraction of the second additive ranges from 0.5% to 3%. Consequently, the rated power, high-temperature performance, and service life of the battery containing the electrolyte can be improved.

[0017] In a third aspect of the present disclosure, a battery is provided. The battery includes the electrolyte additive or electrolyte described above. Consequently, the battery possesses all the features and advantages of the electrolyte additive and electrolyte described above, which are not described in detail in this document.

[0018] In some embodiments, the battery further includes a negative electrode plate. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer, arranged on at least one side of the negative electrode plate. The negative electrode active material layer comprises a negative electrode active material. In some embodiments, the mass fraction of the element silicon in the electrolyte ranges from 3% to 50%. Consequently, the energy density of the battery can be improved.

[0019] In a fourth aspect of the present disclosure, an electrical device is provided. The electrical device includes the battery described above. Consequently, the electrical device has all the features and advantages of the battery described above that are not described in detail in this document. DETAILED DESCRIPTION

[0020] Unless otherwise defined, all technical and scientific terms used herein have the meanings generally understood by a person skilled in the art in the field to which this disclosure belongs. The terms used herein serve only to describe certain embodiments and are not intended to limit the scope of this disclosure. Unless otherwise specified, numerical values ​​of various parameters mentioned herein may be measured using various measurement methods commonly used in the field (for example, measurement may be carried out using the methods set forth in the embodiments of this disclosure).

[0021] The words “comprise / include” and “exhibit” used in the description and claims of the present disclosure are open-ended expressions, meaning that they include the content specified herein but do not exclude other aspects.

[0022] In the description of this disclosure, all numbers disclosed herein are approximate values, regardless of whether the words "about" or "approximately" are used. The difference may be 10% or less, or any difference considered appropriate by a person skilled in the art for each numerical value, for example, a difference of 1%, 2%, 3%, 4%, or 5%.

[0023] In the description of this disclosure, the words "first" and "second" are used solely for descriptive purposes and cannot be understood as indicating or implying any relative meaning or implicitly indicating the number of specified technical features. Consequently, the expressions "the first feature" and "the second feature" may include one or more of the features.

[0024] In the description of this disclosure, the expression “A and / or B” can encompass any of three situations: only A, only B, or both A and B. A and B are used merely as examples and can represent any technical features connected by “and / or” in this description.

[0025] The amount of electrolyte additives constitutes only a small fraction of the electrolyte in a lithium-ion battery. A suitable amount of additives can form a solid electrolyte interface (SEI) on the surface of an active material at the negative electrode and a cathode electrolyte interface (CEI) on the surface of an active material at the positive electrode. SEI and CEI form films on the surfaces of the active materials at the negative and positive electrodes, respectively, effectively reducing the problem of side reactions that occur after direct contact between the active materials and the electrolyte.

[0026] The electrolyte additive tetravinylsilane exhibits a high HOMO energy level and consequently forms a predominantly Si-C organic polymer film on the interface of the positive electrode's active material in the electrolyte before the solvent is added, after the battery's capacity classification is complete. This reduces direct contact between the positive electrode's active material and the electrolyte, effectively minimizing degradation and gas generation by other electrolyte components at the positive electrode interface under high voltage, as well as corrosion by acids and structural degradation of the positive electrode's active material. As a result, the cycle life of the lithium-ion battery can be significantly improved. Furthermore, tetravinylsilane also contributes to film formation on the positive electrode interlayer (SEI).However, the SEI film formed by tetravinylsilane is thick and uneven in thickness, which increases the battery's internal resistance and impairs its rated performance. Furthermore, if a silicon-based material is used as the active material of the negative electrode, lithium atoms penetrate a silicon crystal due to the unsatisfactory uniformity of the tetravinylsilane SEI film structure, forming Li. 15 Si4, which results in some lithium ions being unable to participate in another charge-discharge cycle of the battery, causing an irreversible loss of capacity in the battery.

[0027] Lithium tetrafluoro(oxalato)phosphate exhibits a potential for earlier SEI film formation compared to tetravinylsilane, meaning that it forms a film sooner. Consequently, lithium tetrafluoro(oxalato)phosphate can preferentially form an inorganic film on the surface of the active material of the negative electrode. This film should be rich in phosphates and LiF and exhibit high uniformity of thickness. This can prevent the penetration of lithium atoms into the silicon crystal and the formation of Li 15The silicon-based material inhibits Si4. This allows the battery's capacity to be maintained during the charge-discharge cycle, thus improving its cycle life. After the formation of the SEI film by lithium tetrafluoro(oxalato)phosphate, tetravinylsilane forms a predominantly Si-C organic polymer film on the outer surface of the inorganic film, rich in phosphates and LiF. These substances together reduce the impedance of the negative electrode.

[0028] Furthermore, free fluoride ions in lithium tetrafluoro(oxalato)phosphate combine with free hydrogen ions in the electrolyte to form hydrofluoric acid, resulting in a relatively high overall acidity of the electrolyte. During long-term high-temperature storage (for example, at an ambient temperature of 40 °C, the temperature of the battery of an electric vehicle parked outdoors can reach 70 °C), the hydrofluoric acid attacks both the active material of the positive electrode and the active material of the negative electrode, causing serious side reactions that lead to a voltage drop in the battery and a significant reduction in the capacity retention rate.

[0029] A Si-O bond and a Si-C=C bond in tris[ethenyl(dimethyl)silyl]phosphate (CAS No.: 113419-25-3) break down upon reaction with the hydrofluoric acid in the electrolyte, contributing to a reduction in acidity. Furthermore, tris[ethenyl(dimethyl)silyl]phosphate also promotes the formation of the CEI film and the SEI film. The addition of tris[ethenyl(dimethyl)silyl]phosphate can effectively reduce the adverse increase in electrolyte acidity caused by lithium tetrafluoro(oxalato)phosphate and improve the electrolyte's resistance to high temperatures, thus enhancing the battery's high-temperature performance.

[0030] In a first aspect of the present disclosure, an electrolyte additive for a battery with a silicon-based negative electrode is provided. The electrolyte additive comprises a first additive and a first lithium salt. The first additive comprises tetravinylsilane and tris[ethenyl(dimethyl)silyl]phosphate. The first lithium salt comprises lithium tetrafluoro(oxalato)phosphate. In the present disclosure, the combination of tetravinylsilane, tris[ethenyl(dimethyl)silyl]phosphate, and lithium tetrafluoro(oxalato)phosphate not only facilitates the formation of the SEI film and the CEI film, both of which exhibit low interfacial impedance, thus improving the cycle performance of the battery containing this additive combination, but it also significantly improves the performance after high-temperature storage of the battery containing the silicon-based negative electrode, thereby broadening the battery's application scenarios.

[0031] In some embodiments, the electrolyte additive contains a mass fraction of tetravinylsilane a, and a mass fraction of lithium tetrafluoro(oxalato)phosphate b, where a / b ranges from 0.05 to 20.

[0032] For example, a / b can be 0.05, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5 or 20.

[0033] By rationally determining the proportions of tetravinylsilane and lithium tetrafluoro(oxalato)phosphate, the formation of a uniform and robust CEI and SEI film for a battery system containing the silicon-based negative electrode is facilitated.

[0034] Compared to other lithium salt additives, lithium tetrafluoro(oxalato)phosphate exhibits a lower film formation potential, a lower tendency to decompose and gas formation, and excellent chemical stability.

[0035] In some embodiments, the electrolyte additive contains a mass fraction of lithium tetrafluoro(oxalato)phosphate (b) and a mass fraction of tris[ethenyl(dimethyl)silyl]phosphate (c), where b / c ranges from 0.05 to 20. This allows for improved performance after high-temperature storage of the battery containing the electrolyte additive.

[0036] For example, b / c can be 0.05, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5 or 20.

[0037] Compared to other additives containing Si-O bonds and Si-C=C bonds, Tris[ethenyl(dimethyl)silyl]phosphate exhibits excellent chemical stability, higher ionic conductivity, and greater compatibility.

[0038] In some embodiments, the electrolyte additive further includes a second additive. The second additive includes at least one of a high-temperature additive, a film-forming additive for negative electrodes, a lithium salt additive, or a water / acid scavenger additive.

[0039] Adding the second additive can improve the rated power, high-temperature cycle performance, and lifespan of the battery containing the electrolyte additive.

[0040] In some embodiments, the high-temperature additive includes at least one of 1,3-propanesultone (PS), 1,3-propanesultone (PST), ethylene sulfate (DTD) or ethylene sulfite (ES).

[0041] Adding the high-temperature additive can improve the high-temperature resistance of the electrolyte.

[0042] In some embodiments, the film-forming additive for negative electrodes includes at least one of vinylene carbonate (VC), fluoroethylene carbonate (FEC) or vinylethylene carbonate (VEC).

[0043] By adding the film-forming additive for negative electrodes, the formation of SEI film can be improved and the uniformity of SEI film formation can be optimized.

[0044] In some embodiments, the lithium salt additive includes at least one of lithium bis(oxalato)borate (LiBOB), lithium difluoro(oxalato)borate (LiODFB), lithium difluorobis(oxalato)phosphate (LiODFP), lithium tetrafluoroborate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(pentafluoroethanesulfonyl)imide, lithium trifluoromethanesulfonate or lithium difluorophosphate (LiPO2F2).

[0045] By adding the lithium salt additive, the solubility of the lithium salt in the electrolyte is improved, the stability of the electrolyte at high temperatures is improved, the ionic conductivity of the electrolyte is increased, the hydrolysis of the electrolyte under humid conditions is reduced, and the oxidation of the electrolyte is suppressed.

[0046] In some embodiments, the water / acid scavenger additive includes at least one of tris(trimethylsilyl)borate (TMSB) or tris(trimethylsilyl)phosphate (TMSP).

[0047] By adding the water / acid scavenger additive, reactions with water and acidic substances, such as hydrofluoric acid, can occur in the electrolyte, thus reducing the influence of water and / or acids on the electrolyte's stability. Furthermore, after rinsing with water and acid, the water / acid scavenger additive can also contribute to the formation of the SEI and CEI films.

[0048] In a second aspect of the present disclosure, an electrolyte is provided. The electrolyte includes the electrolyte additive described above. Consequently, the electrolyte exhibits all the features and advantages of the electrolyte additive described above, which are not described in detail herein.

[0049] In some embodiments, the electrolyte further comprises a solvent and an electrolyte lithium salt. The electrolyte lithium salt comprises at least one of lithium hexafluorophosphate or lithium bis(fluorosulfonyl)imide.

[0050] The solvent is a key component of the electrolyte. The solvent should provide high solubility for the lithium salt, enabling the electrolyte to exhibit high ionic conductivity.

[0051] When the electrolyte lithium salt dissolves in the electrolyte solvent, lithium ions are released. These lithium ions form a solvation structure with the electrolyte, which facilitates rapid migration of the lithium ions.

[0052] In some embodiments, the mass fraction of the electrolyte lithium salt in the electrolyte ranges from 12% to 18%.

[0053] For example, the mass fraction of the electrolyte lithium salt in the electrolyte can be 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15%, 15.5%, 16%, 16.5%, 17%, 17.5% or 18%.

[0054] If the mass fraction of the electrolyte lithium salt in the electrolyte decreases within the aforementioned range, the electrolyte lithium salt can dissolve sufficiently in the electrolyte solvent, resulting in high ionic conductivity and low costs for the production of the electrolyte.

[0055] In some embodiments, the solvent may include at least one of ethylene carbonate (ES), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), ethyl propionate, propyl propionate, methyl acetate, ethyl acetate, propyl acetate or methyl propionate.

[0056] The solvent in the electrolyte serves as an important carrier for ion transport. After dissolving the lithium electrolyte salt in the solvent, the electrolyte exhibits high electronic conductivity. Consequently, selecting the appropriate solvent can improve the battery's lifespan and charge / discharge frequency.

[0057] In some embodiments, a mass fraction of the solvent in the electrolyte of 50% to 80% is sufficient.

[0058] For example, the mass fraction of the solvent in the electrolyte can be 55%, 57%, 60%, 63%, 65%, 67%, 70%, 73%, 75%, 77% or 80%.

[0059] In some embodiments, the mass fraction of tetravinylsilane in the electrolyte ranges from 0.1% to 2%.

[0060] For example, the mass fraction of tetravinylsilane in the electrolyte can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, or 2.0%.

[0061] If the mass fraction of tetravinylsilane in the electrolyte ranges from 0.1% to 2%, the tetravinylsilane content is moderate, allowing for sufficient CEI film formation with adequate thickness. Furthermore, after the tetravinylsilane is consumed during CEI film formation, a smaller amount remains, which can reduce gas generation from side reactions and tetravinylsilane decomposition.

[0062] In some embodiments, a mass fraction of lithium tetrafluoro(oxalato)phosphate in the electrolyte ranges from 0.1% to 2%.

[0063] For example, the mass fraction of lithium tetrafluoro(oxalato)phosphate in the electrolyte can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% or 2.0%.

[0064] If the mass fraction of lithium tetrafluoro(oxalato)phosphate in the electrolyte ranges from 0.1% to 2%, lithium tetrafluoro(oxalato)phosphate can form a uniform SEI film earlier than tetravinylsilane, which inhibits direct film formation of tetravinylsilane on the surface of the active material of the negative electrode and improves the uniformity of the thickness of the SEI film.

[0065] In some embodiments, the mass fraction of tris[ethenyl(dimethyl)silyl]phosphate in the electrolyte ranges from 0.1% to 2%. Consequently, the performance of the battery containing the electrolyte can be improved after high-temperature storage.

[0066] For example, the mass fraction of tris[ethenyl(dimethyl)silyl]phosphate in the electrolyte can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% or 2.0%.

[0067] When the mass fraction of tris[ethenyl(dimethyl)silyl]phosphate in the electrolyte ranges from 0.1% to 2%, tris[ethenyl(dimethyl)silyl]phosphate can effectively consume acidic substances in the electrolyte, such as hydrofluoric acid, which at high temperatures effectively reduces side reactions between each of the active material of the positive electrode and the active material of the negative electrode as well as the acidic substances and improves the cycle performance and high-temperature performance of the battery.

[0068] In some embodiments, the mass fraction of the second additive ranges from 0.5% to 3%.

[0069] For example, the mass fraction of the second additive in the electrolyte can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, or 3.0%.

[0070] If the second additive contains the high-temperature additive, a mass fraction of the high-temperature additive in the electrolyte of, for example, 0% to 2% is sufficient.

[0071] If the second additive contains the film-forming additive for negative electrodes, a mass fraction of the film-forming additive for negative electrodes in the electrolyte of, for example, 0.5% to 3% is sufficient.

[0072] If the second additive contains the lithium salt additive, a mass fraction of the lithium salt additive in the electrolyte of, for example, 0% to 1% is sufficient.

[0073] If the second additive contains the water / acid scavenger additive, a mass fraction of the water / acid scavenger additive in the electrolyte of, for example, 0% to 1% is sufficient.

[0074] In a third aspect of the present disclosure, a battery is provided. The battery includes the electrolyte additive or electrolyte described above. Consequently, the battery possesses all the features and advantages of the electrolyte additive and electrolyte described above, which are not described in detail in this document.

[0075] Under normal circumstances, a battery contains a positive electrode plate, a negative electrode plate, an electrolyte, and a separator. During charging or discharging, active ions move between the positive and negative electrode plates by intercalating into and deintercalating from them. The electrolyte acts as a conductor for ions between the positive and negative electrode plates. The separator is placed between the positive and negative electrode plates and primarily serves to prevent short circuits between them while allowing ions to flow through.

[0076] In some embodiments, the battery further includes a negative electrode plate. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer, arranged on at least one side of the negative electrode plate. The negative electrode active material layer comprises a negative electrode active material. In some embodiments, the mass fraction of the element silicon in the electrolyte ranges from 3% to 50%.

[0077] By increasing the specific capacity of the active material in the negative electrode, the battery's energy density can be effectively improved. The specific capacity of a conventional graphite-based material has already reached its theoretical upper limit (372 mAh / g), while a maximum theoretical specific capacity of a silicon-based negative electrode material can reach 4,200 mAh / g, making silicon-based materials extremely promising for use. During charging or discharging, the silicon-based negative electrode material undergoes significant volume changes.During repeated charge-discharge cycles, excessive volume expansion and contraction of the silicon-based negative electrode material leads to repeated tearing and reformation of the silicon-based negative electrode, which continuously consumes the electrolyte and results in unsatisfactory cycle performance of the battery.

[0078] In the present disclosure, by optimizing the composition of the electrolyte additive on the surface of the silicon-based active material of the negative electrode, a SEI film with high structural stability can be formed. Even if the silicon-based active material of the negative electrode undergoes significant volume changes during charge-discharge cycles, the SEI film can still effectively adhere to the surface of the active material of the negative electrode, which effectively reduces electrolyte consumption caused by repeated tearing and reformation of the SEI film and improves the cycle performance of the battery.

[0079] In some embodiments, the battery includes a positive electrode plate. The positive electrode plate includes a current collector for the positive electrode and an active material layer for the positive electrode, arranged on at least one side surface of the positive electrode plate. The active material layer for the positive electrode comprises an active material for the positive electrode. The active material for the positive electrode contains a mass fraction of nickel greater than or equal to 40%.

[0080] If the mass fraction of the element nickel in the active material of the positive electrode decreases within the aforementioned range, the cost of the active material of the positive electrode is low, and the capacity per gram of the active material of the positive electrode is significantly improved.

[0081] Preferably, the active material of the positive electrode corresponds to the general formula Li a Ni b Co cM16M2 e O f R g , where 1≤a≤1,2, 0,6 <b<1, 0<c<1, 0<d<1, 0≤e≤0,2, b+c+d+e=1, 1<f<2, 0≤g≤1, f+g=2; beinhaltet M1 Mn und / oder Al, beinhaltet M2 mindestens eines von Zr, Zn, Cu, Cr, Mg, Fe, V, Ti, Sr, Sb, Y, W oder Nb und beinhaltet R mindestens eines von N, F, S oder Cl.

[0082] In some embodiments, the active material of the positive electrode can be at least one of LiNi. 0,7 Co 0,1 Mn 0,2 O2 (NCM712), LiNi 0,8 Co 0,1 Mn 0,1 O2 (NCM811), LiNi 0,8 Co 0,15 Al 0,05 O2 or LiNi 0,9 Co 0,05 Mn 0,05 O2 is included. In this way, the capacity per gram of the positive electrode active material can be further improved, and the cost of the positive electrode active material can be reduced.

[0083] During charging or discharging of the battery, deintercalation and consumption of lithium can occur. As the battery is discharged to different states, the lithium content in the active material of the positive electrode varies accordingly. In the listing of the active materials of the positive electrode in the present disclosure, a molar content of lithium refers to an initial state of the material. As the active material of the positive electrode is used in the battery and undergoes cyclic charging and discharging, the molar content of lithium changes.

[0084] In the list of active materials of the positive electrode in the present disclosure, the molar content of O is merely a theoretical state variable. During the cyclic charging and discharging of the battery, the release of lattice oxygen from the active material of the positive electrode causes a change in the molar content of oxygen.

[0085] In some embodiments of the present disclosure, the positive electrode current collector may include a metal foil or a composite material current collector. The metal foil may, for example, be an aluminum foil. The composite material current collector may include a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. The composite material current collector may be formed by forming a metallic material (e.g., aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy) on a polymer substrate material (e.g., polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE)).

[0086] In some embodiments, the active material layer of the positive electrode may optionally comprise a binder. The binder may, for example, comprise at least one of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene propylene terpolymer, vinylidene fluoride-hexafluoropropylene tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, or fluorine-containing acrylate resin.

[0087] In some embodiments, the active material layer of the positive electrode may optionally comprise a conductive medium. For example, the conductive medium may include at least one made of superconducting carbon, acetylene black, carbon black, ketone black, a carbon dot, a carbon nanotube, graphene, or a carbon nanofiber.

[0088] In some embodiments, the negative electrode plate includes a negative electrode current collector and a negative electrode active material layer arranged on at least one surface of the negative electrode current collector. The negative electrode active material layer comprises a negative electrode active material. The negative electrode active material can comprise at least one of synthetic graphite, natural graphite, soft carbon, hard carbon, a mesocarbon microbead, a silicon-based material, a tin-based material, or lithium titanate.

[0089] In some embodiments, the active material layer of the negative electrode may further comprise a binder, a conductive agent, and other additives. For example, the binder may comprise at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), or carboxymethyl chitosan (CMCS); the conductive agent may comprise at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, a carbon dot, a single-walled carbon nanotube, graphene, or a carbon nanofiber; the additives may include a thickening agent such as sodium carboxymethyl cellulose (CMC-Na).

[0090] The present disclosure does not specifically limit the type of separator. Any porous separator with satisfactory chemical and mechanical stability may be selected. For example, the separator material may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, or polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film.

[0091] The battery of the present disclosure can be in the form of a battery cell, a battery module or a battery pack.

[0092] In some embodiments, battery cells can be assembled into a battery module. The battery module can contain one or more battery cells. Based on the application and the capacity of the battery module, a person skilled in the art can select a specific number of battery cells.

[0093] In some embodiments, battery modules can also be assembled into a battery pack. The battery pack can contain one or more battery modules. Based on the application and the capacity of the battery pack, a person skilled in the art can select a specific number of battery modules.

[0094] In a fourth aspect of the present disclosure, an electrical device is provided. The electrical device includes the battery described above. Consequently, the electrical device has all the features and advantages of the battery described above that are not described in detail in this document.

[0095] The battery cell, battery module, or battery pack can be used as an energy source or energy storage unit for the electrical device. The electrical device can include, but is not limited to, a mobile device (e.g., a mobile phone, a laptop computer, etc.), an electric vehicle (e.g., a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc.), an electric train, a ship, a satellite, an energy storage system, etc.

[0096] The battery, battery module or battery pack can be selected based on a usage requirement of the electrical device.

[0097] According to one embodiment, the electrical device can be a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, etc. To meet the electrical device's requirements for high energy and high energy density, a battery pack or battery module can be used.

[0098] According to another embodiment, the electrical device can be a mobile phone, a tablet computer, a laptop computer, etc. Such electrical devices generally require a slim design and low weight, and consequently, a battery cell can be used as the energy source.

[0099] The solutions of this disclosure are described below with reference to specific examples. It should be noted that the examples described below serve only to illustrate this disclosure and should not be interpreted as limiting its scope. Where no specific techniques or conditions are indicated in the examples, the procedures are to be carried out according to the techniques and conditions described in the literature of the relevant field or according to the product description. The reagents or instruments used without reference to the manufacturers are all conventional products that can be purchased commercially. Example 1: Production of the positive electrode plate:

[0100] The positive electrode active material NCM811, the binder polyvinylidene fluoride (PVDF), and the conductive agent acetylene black were mixed at a mass ratio of 96.5:2:1.5. N-methylpyrrolidone (NMP) was added and stirred using a vacuum mixer until the mixture became a positive electrode slurry with homogeneous fluidity. The positive electrode slurry was applied evenly to two surfaces of an aluminum foil. The aluminum foil coated with the positive electrode slurry was dried in an oven at 120 °C for 8 hours. Finally, the dried aluminum foil was rolled and joints were incorporated to create the positive electrode plate. Production of the negative electrode plate:

[0101] The active material of the negative electrode, synthetic graphite, silicon monoxide, sodium carboxymethylcellulose (CMC-Na), styrene-butadiene rubber, conductive carbon black (SP), and single-walled carbon nanotube (SWCNT), was mixed in a mass ratio of 79.5:15:1:1.5:1:0.5. Deionized water was added. The mixture was stirred in a vacuum mixer to obtain a negative electrode slurry. The negative electrode slurry was applied evenly to two surfaces of a copper foil. The copper foil coated with the negative electrode slurry was air-dried at room temperature and then transported to an oven and dried at 80 °C for 10 hours. Subsequently, cold pressing and jointing were performed to obtain the negative electrode plate. Production of an electrolyte:

[0102] In an argon-filled glovebox (humidity <10 ppm, oxygen <1 ppm), the solvents EC:EMC:DEC were mixed uniformly based on a mass ratio of 3:5:2. A thoroughly dried electrolyte lithium salt LiPF6 with a mass fraction of 14.5% and electrolyte additives were rapidly added to the mixed solvent. The electrolyte additives comprised the first additive and the first lithium salt. The first additive was tetravinylsilane and tris[ethenyl(dimethyl)silyl]phosphate (CAS No.: 113419-25-3). The first lithium salt was lithium tetrafluoro(oxalato)phosphate. The types and mass fractions of the additives in the electrolyte are shown in Table 1. After thorough mixing, the mixture was stirred uniformly to obtain the electrolyte. Manufacturing the separator:

[0103] A polyethylene separator with a thickness of 8 µm was selected. Manufacturing a lithium-ion battery:

[0104] The manufactured positive electrode plate, separator, and negative electrode plate were wound together to create an unimpregnated raw cell. This raw cell was then placed in an outer casing. The prepared electrolyte was injected into the dried raw cell. After processes such as vacuum sealing, curing, forming, molding, and sorting, the lithium-ion battery was complete.

[0105] The lithium-ion batteries in Examples 2 to 36 and Comparative Examples 1 to 7 were all manufactured on the basis of the manufacturing process described above, with the differences shown in Table 1.

[0106] Examples 2 to 6 differ from example 1 in the amount of lithium tetrafluoro(oxalato)phosphate.

[0107] Examples 7 to 11 differ from example 3 in the amount of tetravinylsilane.

[0108] Example 12 differs from Example 2 in the amount of tetravinylsilane.

[0109] Examples 13 to 17 differ from example 3 in the amount of lithium tetrafluoro(oxalato)phosphate.

[0110] Example 18 differs from Example 2 in the amount of tris[ethenyl(dimethyl)silyl]phosphate.

[0111] Example 19 differs from Example 5 in the amount of tris[ethenyl(dimethyl)silyl]phosphate.

[0112] Examples 20 to 28 differ from example 3 in one substance and one quantity of the second additive.

[0113] Examples 29 to 31 differ from Example 1 in the use of different active materials for the negative electrode. Specifically, in Examples 29, 30, and 31, natural graphite, hard carbon, and lithium titanate, respectively, were used as replacements for the synthetic graphite used in Example 1.

[0114] Examples 32 and 33 differ from Example 1 in the use of different active materials for the positive electrode. Specifically, LiNi was used in Examples 32 and 33 to replace the NCM811 in Example 1. 0,7 Co 0,1 Mn 0,2 O2 or LiNi 0,9 Co 0,05 Mn 0,05 O2 is used.

[0115] Examples 34 to 36 differ from Example 1 in the use of different negative electrode plates.

[0116] Specifically, in Example 34, the active material of the negative electrode—artificial graphite, silicon monoxide, sodium carboxymethylcellulose (CMC-Na), styrene-butadiene rubber, conductive carbon black (SP), and single-walled carbon nanotube (SWCNT)—was mixed based on a mass ratio of 91.5:3:1:1.5:1:0.5. Deionized water was added. The mixture was stirred in a vacuum mixer to obtain the slurries for the negative electrode.

[0117] In Example 35, the active material of the negative electrode—artificial graphite, silicon monoxide, sodium carboxymethylcellulose (CMC-Na), styrene-butadiene rubber, conductive carbon black (SP), and single-walled carbon nanotube (SWCNT)—was mixed based on a mass ratio of 74.5:20:1:1.5:1:0.5. Deionized water was added. The mixture was stirred in a vacuum mixer to obtain the slurry for the negative electrode.

[0118] In Example 36, the active material of the negative electrode—artificial graphite, silicon monoxide, sodium carboxymethylcellulose (CMC-Na), styrene-butadiene rubber, conductive carbon black (SP), and single-walled carbon nanotube (SWCNT)—was mixed based on a mass ratio of 64.5:30:1:1.5:1:0.5. Deionized water was added. The mixture was stirred in a vacuum mixer to obtain the slurry for the negative electrode.

[0119] Comparison examples 1 to 7 differ from example 3 as follows: In comparison example 1, neither the first additive nor the first lithium salt was added; in comparison example 2, neither lithium tetrafluoro(oxalato)phosphate nor tris[ethenyl(dimethyl)silyl]phosphate was added; in comparison example 3, neither tetravinylsilane nor tris[ethenyl(dimethyl)silyl]phosphate was added; in comparison example 4, neither tetravinylsilane nor lithium tetrafluoro(oxalato)phosphate was added; in comparison example 5, no tris[ethenyl(dimethyl)silyl]phosphate was added; in comparison example 6, no lithium tetrafluoro(oxalato)phosphate was added; in comparison example 7, no tetravinylsilane was added. Table 1 Nr. Mass fraction (%) in the electrolyte Substance and mass fraction (%) of the second additive away b / c Tetravinylsilane Lithium tetrafluoro-(oxalato)phosphate Tris[ethenyl(dimethyl)silyl]phosphate Example 1 0,1 0,05 0,5 PS, 1; FEC, 10; VC, 0.5 2 0,1 Example 2 0,1 0,1 0,5 PS, 1; FEC, 10; VC, 0.5 1 0,2 Example 3 0,1 0,5 0,5 PS, 1; FEC, 10; VC, 0.5 0,2 1 Example 4 0,1 1 0,5 PS, 1; FEC, 10; VC, 0.5 0,1 2 Example 5 0,1 2 0,5 PS, 1; FEC, 10; VC, 0.5 0,05 4 Example 6 0,1 3 0,5 PS, 1; FEC, 10; VC, 0.5 0,03 6 Example 7 0,5 0,5 0,5 PS, 1; FEC, 10; VC, 0.5 1 1 Example 8 1 0,5 0,5 PS, 1; FEC, 10; VC, 0.5 2 1 Example 9 2 0,5 0,5 PS, 1; FEC, 10; VC, 0.5 4 1 Example 10 0,05 0,5 0,5 PS, 1; FEC, 10; VC, 0.5 0,1 1 Example 11 2,5 0,5 0,5 PS, 1; FEC, 10; VC, 0.5 5 1 Example 12 2 0,1 0,5 PS, 1; FEC, 10; VC, 0.5 20 0,2 Example 13 0,1 0,5 0,05 PS, 1; FEC, 10; VC, 0.5 0,2 10 Example 14 0,1 0,5 0,1 PS, 1; FEC, 10; VC, 0.5 0,2 5 Example 15 0,1 0,5 1 PS, 1; FEC, 10; VC, 0.5 0,2 0,5 Example 16 0,1 0,5 2 PS, 1; FEC, 10; VC, 0.5 0,2 0,25 Example 17 0,1 0,5 2,5 PS, 1; FEC, 10; VC, 0.5 0,2 0,2 Example 18 0,1 0,1 2 PS, 1; FEC, 10; VC, 0.5 1 0,05 Example 19 0,1 2 0,1 PS, 1; FEC, 10; VC, 0.5 0,05 20 Example 20 0,1 0,5 0,5 PS, 1; DTD, 1; VC, 0.5 0,2 1 Example 21 0,1 0,5 0,5 PS, 1; DTD, 1; TMSP, 0,2 1 0,3 Example 22 0,1 0,5 0,5 PST, 0.5; TMSB, 0.3; LiODFP, 0.3 0,2 1 Example 23 0,1 0,5 0,5 PS, 1; ES, 0,3; LiODFB,0,3 0,2 1 Example 24 0,1 0,5 0,5 PST, 0.5; TMSB, 0.3; LiPO2F2, 0.3 0,2 1 Example 25 0,1 0,5 0,5 \ 0,2 1 Example 26 3 0,1 0,1 PS, 1; FEC, 10; VC, 0.5 30 1 Example 27 0,9 0,09 3 PS, 1; FEC, 10; VC, 0.5 10 0,03 Example 28 1,5 3 0,1 PS, 1; FEC, 10; VC, 0.5 0,5 30 Example 29 0,1 0,05 0,5 PS, 1; FEC, 10; VC, 0.5 2 0,1 Example 30 0,1 0,05 0,5 PS, 1; FEC, 10; VC, 0.5 2 0,1 Example 31 0,1 0,05 0,5 PS, 1; FEC, 10; VC, 0.5 2 0,1 Example 32 0,1 0,05 0,5 PS, 1; FEC, 10; VC, 0.5 2 0,1 Example 33 0,1 0,05 0,5 PS, 1; FEC, 10; VC, 0.5 2 0,1 Example 34 0,1 0,05 0,5 PS, 1; FEC, 10; VC, 0.5 2 0,1 Example 35 0,1 0,05 0,5 PS, 1; FEC, 10; VC, 0.5 2 0,1 Example 36 0,1 0,05 0,5 PS, 1; FEC, 10; VC, 0.5 2 0,1 Comparative example 1 \ \ \ PS, 1; FEC, 1; VC, 0.5 \ \ Comparative example 2 0,1 \ \ PS, 1; FEC, 1; VC, 0.5 \ \ Comparative example 3 \ 0,5 \ PS, 1; FEC, 1; VC, 0.5 \ \ Comparative example 4 \ \ 0,5 PS, 1; FEC, 1; VC, 0.5 \ \ Comparative example 5 0,1 0,5 \ PS, 1; FEC, 1; VC, 0.5 0,2 \ Comparative example 6 0,1 \ 0,5 PS, 1; FEC, 1; VC, 0.5 \ \ Comparative example 7 \ 0,5 0,5 PS, 1; FEC, 1; VC, 0.5 \ 1

[0120] Electrochemical performance tests were performed on the lithium-ion batteries obtained in the preceding comparison examples and examples. The test results are shown in Table 2. (1) Test after storage at 60 °C: The received battery was placed in an environment at 25 °C and discharged at a constant current of 1 C to a cut-off voltage of 2.75 V. The capacity was recorded as the initial capacity Q1. The battery was allowed to rest for 5 min, then charged at a constant current of 1 C and a constant voltage to an upper voltage limit of 4.2 V with a cut-off current of 0.05 C. An initial battery voltage was measured as V1. The lithium-ion battery was placed in a high-temperature chamber at a temperature of 60 °C and then left to rest for 30 days. The battery was removed and placed at room temperature for 4 hours. When the battery temperature had dropped to room temperature, the battery voltage V2 was measured. Then the battery was discharged at a constant current of 1 C to a cut-off voltage of 2.75 V. The capacity was recorded as Q2.The battery was left to rest for 5 minutes, then charged with a constant current of 1C and a constant voltage up to the upper voltage limit of 4.2V with a cutoff current of 0.05C. The capacity was measured as Q3. The following formulas were used: voltage drop = V1 - V2, and capacity maintenance rate = Q2 / Q1 × 100%. (2) EIS test at -20 °C: The battery was charged with a constant current of 1 C and a constant voltage up to the upper voltage limit of 4.2 V with a cutoff current of 0.05 C. The fully charged battery was left to rest for 10 hours at -20 °C. An EIS test was performed. A potential was set to a resting voltage. A sinusoidal voltage amplitude ranged from 1 mV to 10 mV. A sampling frequency ranged from 0.1 Hz to 1,000,000 Hz. Using the test data obtained, an installation analysis was performed with the Z-view software to determine the SEI film impedance R. SEI to obtain. (3) Cycle test at 45 °C: The battery was placed in an environment of (45 ± 2) °C and left to rest for 3 hours. It was then charged at a constant current of 1 C and constant voltage up to the upper voltage limit of 4.2 V with a cut-off current of 0.05 C. After the battery was fully charged, it was left to rest for 5 minutes and then discharged at a constant current of 1 C down to the cut-off voltage of 2.75 V. The highest discharge capacity within the first three cycles was recorded as the initial capacity Q3. After 300 cycles, the discharge capacity of the last cycle, Q4, was recorded. The calculation formula was: Capacity maintenance rate (%) = Q4 / Q3 × 100%

[00131] Table 2 Nr. Voltage drop after storage at 60 °C (V) Capacity retention rate after storage at 60 °C (%) R SEI / mΩ Capacity maintenance rate per cycle at 45 °C (%) Example 1 0,062 81,22 10,3 83,2 Example 2 0,058 85,89 9 87,45 Example 3 0,053 88,94 8,4 90,55 Example 4 0,058 86,02 8,5 91,67 Example 5 0,06 84,33 8,7 92,33 Example 6 0,069 79,23 9,6 86,32 Example 7 0,05 90,02 9,3 88,21 Example 8 0,049 89,78 9,2 87,89 Example 9 0,047 90,56 8,6 88,56 Example 10 0,076 78,34 10,6 83,25 Example 11 0,069 76,84 11,4 85,14 Example 12 0,046 87,04 8,1 90,86 Example 13 0,067 80,13 11,1 85,1 Example 14 0,058 85,51 8,2 86,77 Example 15 0,057 84,89 8,5 88,36 Example 16 0,058 83,67 8,8 87,22 Example 17 0,061 83,01 10,1 84,38 Example 18 0,06 83,3 9 86,57 Example 19 0,048 89,61 8,3 87,99 Example 20 0,054 89,05 8,5 89,65 Example 21 0,053 88,78 8,4 90,01 Example 22 0,053 89,12 8,5 90,23 Example 23 0,054 89,1 8,4 89,76 Example 24 0,052 88,8 8,5 89,69 Example 25 0,055 87,69 8,3 90,11 Example 26 0,084 75,25 10,9 81,56 Example 27 0,082 75,62 11,1 81,82 Example 28 0,081 75,44 11,3 82,15 Example 29 0,061 81,41 10,2 83,24 Example 30 0,060 81,46 10,3 83,30 Example 31 0,061 81,25 10,4 83,18 Example 32 0,063 81,10 10,4 83,16 Example 33 0,062 81,31 10,2 83,30 Example 34 0,061 81,16 10,3 83,32 Example 35 0,061 81,06 10,4 83,19 Example 36 0,063 81,27 10,2 83,17 Comparative example 1 0,092 73,34 14,8 72,88 Comparative example 2 0,09 74,66 13,7 75,56 Comparative example 3 0,088 74,48 11,8 76,24 Comparative example 4 0,085 74,55 13,2 77,12 Comparative example 5 0,091 74,03 11,6 81,34 Comparative example 6 0,087 74,12 12,5 80,67 Comparative example 7 0,086 74,79 11,6 79,85

[0121] Table 2 shows that in Examples 1 to 36, the electrolyte contained a combination of electrolyte additives, including tetravinylsilane, tris[ethenyl(dimethyl)silyl]phosphate, and lithium tetrafluoro(oxalato)phosphate. The impedance of the SEI film on the surface of the active material of the negative electrode was low. The internal resistance of the battery was low. Electrolyte decomposition and gas generation could be effectively suppressed. The battery exhibited satisfactory cycle performance and performance after high-temperature storage. In Comparative Example 1, the first additive and the first lithium salt of the present disclosure were not added to the electrolyte; in this case, the impedance of the SEI film of the battery was high, and the battery exhibited unsatisfactory cycle performance and performance after high-temperature storage. In Comparative Example 2, only tetravinylsilane was added to the electrolyte.Due to the unsatisfactory uniformity of the SEI film formed by the tetravinylsilane on the surface of the negative electrode's active material, the SEI film's impedance remained high. In comparative example 3, only lithium tetrafluoro(oxalato)phosphate was added to the electrolyte, which helped reduce the SEI film's impedance on the surface of the negative electrode's active material, but had only a minor effect on improving the battery's cycle life. In comparative example 4, only tris[ethenyl(dimethyl)silyl]phosphate was added to the electrolyte, which improved the battery's performance after high-temperature storage, but only marginally improved the battery's cycle life and the SEI film's impedance on the surface of the negative electrode's active material.In comparative example 5, both tetravinylsilane and lithium tetrafluoro(oxalato)phosphate were added to the electrolyte, resulting in low SEI film impedance and effective suppression of electrolyte decomposition and gas generation. Furthermore, the battery exhibited satisfactory cycle performance but unsatisfactory performance after high-temperature storage. In comparative example 6, both tetravinylsilane and tris[ethenyl(dimethyl)silyl]phosphate were added to the electrolyte, resulting in satisfactory battery cycle performance. Due to the absence of lithium tetrafluoro(oxalato)phosphate, which has the potential for earlier film formation than tetravinylsilane, the SEI film impedance on the surface of the negative electrode's active material was high, and the battery's internal resistance was high.In comparative example 7, both lithium tetrafluoro(oxalato)phosphate and tris[ethenyl(dimethyl)silyl]phosphate were added to the electrolyte, which helped to improve the performance after high-temperature storage and the impedance of the battery's SEI film. However, since the decomposition and gas generation of the electrolyte could not be effectively suppressed, the battery's cycle performance was unsatisfactory.

[0122] It should be noted that the foregoing embodiments are only examples and that the present disclosure is not limited to them. Embodiments with substantially the same composition as the technical concept, which have the same functional effect within the scope of the technical solutions of the present disclosure, are included within the technical scope of the present disclosure. Without deviating from the scope of the essence of the present disclosure, various modifications conceivable by a person skilled in the art may be applied to the embodiments, or some or all of the technical features contained therein may be replaced with equivalent ones. Such modifications or replacements do not result in the essential character of the corresponding technical solutions deviating from the scope of the technical solutions of various embodiments of the present disclosure.All these modifications and substitutions are included within the scope of the appended claims and in the description of the present disclosure.

[0123] The technical features mentioned in each embodiment can be arbitrarily combined without any conflict. The present disclosure is not limited to the specific embodiments disclosed herein and encompasses all technical solutions that fall within the scope of the appended claims. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CH 202311637451.1

[0001]

Claims

[1] Electrolyte additive for a battery with a silicon-based negative electrode, the electrolyte additive comprising: a first additive, wherein the first additive comprises tetravinylsilane and tris[ethenyl(dimethyl)silyl]phosphate; and a first lithium salt, wherein the first lithium salt comprises lithium tetrafluoro(oxalato)phosphate. [2] Electrolyte additive according to claim 1, wherein the electrolyte additive contains a mass fraction of tetravinylsilane a and a mass fraction of lithium tetrafluoro(oxalato)phosphate b, wherein a / b ranges from 0.05 to 20. [3] Electrolyte additive according to claim 1 or 2, wherein the electrolyte additive contains a mass fraction of lithium tetrafluoro(oxalato)phosphate b and a mass fraction of tris[ethenyl(dimethyl)silyl]phosphate c, wherein b / c ranges from 0.05 to 20. [4] Electrolyte additive according to any one of claims 1 to 3, further comprising a second additive, wherein the second additive comprises at least one of a high-temperature additive, a film-forming additive for negative electrodes, a lithium salt additive or a water / acid scavenger additive. [5] Electrolyte additive according to claim 4, wherein the second additive meets at least one of the following conditions: The high-temperature additive comprises at least one of 1,3-propanesultone, 1,3-propenesultone, ethylene sulfate or ethylene sulfite; The film-forming additive for negative electrodes comprises at least one of vinylene carbonate, fluoroethylene carbonate or vinylethylene carbonate; The lithium salt additive comprises at least one of lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium difluorobis(oxalato)phosphate, lithium tetrafluoroborate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(pentafluoroethanesulfonyl)imide, lithium trifluoromethanesulfonate or lithium difluorophosphate; or The water / acid scavenger additive comprises at least one of tris(trimethylsilyl)borate or tris(trimethylsilyl)phosphate. [6] Electrolyte comprising the electrolyte additive according to any one of claims 1 to 5. [7] Electrolyte according to claim 6, further comprising a solvent and an electrolyte lithium salt, wherein the electrolyte lithium salt comprises at least one of lithium hexafluorophosphate or lithium bis(fluorosulfonyl)imide. [8] Electrolyte according to claim 7, wherein the mass fraction of the electrolyte lithium salt in the electrolyte ranges from 12% to 18%. [9] Electrolyte according to any one of claims 6 to 8, wherein the mass fraction of tetravinylsilane in the electrolyte ranges from 0.1% to 2%. [10] Electrolyte according to any one of claims 6 to 9, wherein the mass fraction of lithium tetrafluoro(oxalato)phosphate in the electrolyte ranges from 0.1% to 2%. [11] Electrolyte according to any one of claims 6 to 10, wherein the mass fraction of tris[ethenyl(dimethyl)silyl]phosphate in the electrolyte ranges from 0.1% to 2%. [12] Electrolyte according to any one of claims 6 to 11, wherein the mass fraction of the second additive in the electrolyte ranges from 0.5% to 3%. [13] Battery comprising the electrolyte additive according to any one of claims 1 to 5 or the electrolyte according to any one of claims 6 to 12. [14] Battery according to claim 13, further comprising a negative electrode plate, wherein the negative electrode plate comprises a negative electrode current collector and an active material layer of the negative electrode, arranged on at least one side of the negative electrode plate, wherein the active material layer of the negative electrode comprises an active material of the negative electrode, wherein a mass fraction of the element silicon in the active material of the negative electrode ranges from 3% to 50%. [15] Electrical device comprising the battery according to claim 13 or 14.