Electrolyte, lithium ion battery and power-related equipment

Abstract

The invention provides an electrolyte, a lithium ion battery and power related equipment, and relates to the field of lithium ion batteries. The electrolyte comprises a solvent, and the solvent comprises cyclic carbonate and linear carbonate; the cyclic carbonate is PC (Polycarbonate), and the linear carbonate comprises EMC (Electro Magnetic Compatibility) and DMC (Dimethyl Carbonate); the mass ratio of the PC to the EMC to the DMC is (14-15): (5.5-6.5): (54-56). The electrolyte does not contain EC, a more compact and more stable interfacial film can be formed through mutual cooperation of a specific content and a specific type of solvent, the high-temperature cycle performance of the battery is remarkably improved, the gas production phenomenon is inhibited, and an unexpected high-temperature low-gas production effect is obtained.

Description

Technical Field

[0001] This application relates to the field of lithium-ion batteries, and more particularly to an electrolyte, a lithium-ion battery, and an electrical device. Background Technology

[0002] High-nickel ternary cathode materials (Ni content ≥ 90%) have broad application prospects in the power and energy storage fields due to their high specific energy characteristics. However, under high-temperature cycling conditions, this system generally suffers from electrolyte decomposition and intensified side reactions, leading to a large amount of gas evolution, cell swelling, premature CID flipping, and ultimately battery failure.

[0003] Existing electrolytes used in lithium batteries suffer from the following technical problems: Currently used electrolyte formulations generally contain a high proportion of ethylene carbonate (EC). While this helps form a good SEI on the negative electrode surface, it is easily oxidized and decomposed by the positive electrode surface at high temperatures, or undergoes side reactions on the negative electrode surface, further increasing gas generation. Previous studies have improved cycle stability by introducing additives such as FEC (fluoroethylene carbonate), LiDFOB (lithium difluorooxalate borate), and TVSi (1,3-propenesulfonate lactone), but gas generation at high temperatures remains significant.

[0004] Therefore, developing an electrolyte that can reduce high-temperature side reactions and suppress gas production is crucial for promoting the application of lithium-ion batteries. Summary of the Invention

[0005] The purpose of this application is to provide an electrolyte, a lithium-ion battery, and an electrical device to solve the above-mentioned problems.

[0006] To achieve the above objectives, this application adopts the following technical solution: An electrolyte comprising a solvent, said solvent comprising cyclic carbonates and linear carbonates; The cyclic carbonate is PC, and the linear carbonate includes EMC and DMC; The mass ratio of PC to EMC and DMC is (14~15): (5.5~6.5): (54~56).

[0007] According to an embodiment of this application, based on the total mass of the electrolyte, the content of PC is 14-15 wt%, the content of EMC is 5.5-6.5 wt%, and the content of DMC is 54-56 wt%.

[0008] According to embodiments of this application, the electrolyte further includes lithium salt; The lithium salt includes LiPF6.

[0009] According to an embodiment of this application, the content of the lithium salt in the electrolyte is 14~15 wt%.

[0010] According to embodiments of this application, the electrolyte further includes additives, which include at least one of FEC, LiPO2F2, TMSP, LiDFOB, TPP, and PST.

[0011] According to an embodiment of this application, the additive is present in an amount of 5-12.5 wt% in the electrolyte.

[0012] According to embodiments of this application, the content of FEC in the electrolyte is 5-10 wt%; And / or, the content of LiPO2F2 in the electrolyte is 0-0.5 wt%; And / or, the TMSP content in the electrolyte is 0-0.5 wt%; And / or, the content of LiDFOB in the electrolyte is 0-0.5 wt%; And / or, the TPP content in the electrolyte is 0-0.5 wt%; And / or, the content of PST in the electrolyte is 0-0.5 wt%.

[0013] This application also provides a lithium-ion battery, including the electrolyte described above.

[0014] According to embodiments of this application, the lithium-ion battery further includes a positive electrode and a negative electrode; The positive electrode includes a positive electrode active material, which is LiNi. x Co y Mn z L( 1-x-y-z O2, wherein L includes at least one of Al, Sr, Mg, Ti, Ca, Zr, Zn, Si, and Fe, 0.9 ≤ x < 1, 0 <y≤1,0≤z<1,0<x+y+z≤1。

[0015] This application also provides an electrical device, including the lithium-ion battery described above.

[0016] Compared with the prior art, the beneficial effects of this application include: This application provides an electrolyte free of ethylene carbonate (EC), improving upon the technical problems of traditional electrolytes, such as numerous side reactions and severe gas generation at high temperatures. Specifically, this application, by removing ethylene carbonate (EC), considered a key film-forming agent in traditional electrolytes, overcomes the technical prejudice that the lack of EC leads to ineffective solid electrolyte interphase (SEI) film formation, resulting in severe negative electrode lithium plating, capacity decay, and gas generation problems. The electrolyte of this application, free of EC, through specific amounts and combinations with specific types of solvents, can form a denser and more stable interfacial film, thereby significantly improving the high-temperature cycle performance of the battery, suppressing gas generation, and achieving an unexpected high-temperature, low-gas generation effect. Moreover, the electrolyte of this application does not impair the battery's cycle life at high temperatures. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0018] Figure 1 This is a comparison chart of the internal gas pressure of the batteries in the embodiment and the comparative example after 200 cycles at 45°C. Figure 2 This is a comparison chart showing the relationship between the number of CID rotation cycles and capacity retention rate of the batteries in the examples and comparative examples at 45°C; Figure 3 This is a comparison chart showing the relationship between the number of CID rotation cycles and capacity retention rate of the batteries in the examples and comparative examples at 60°C. Detailed Implementation

[0019] As used in this article: "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0020] The conjunction "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for associated conventional impurities. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0021] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0022] In these embodiments, unless otherwise specified, the portions and percentages are all by weight.

[0023] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has "a" parts by mass and component B has "b" parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (where K is any number representing a multiplier). It is important to understand that, unlike parts by mass, the sum of the mass parts of all components is not limited to 100 parts.

[0024] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0025] This application provides an electrolyte comprising a solvent, wherein the solvent comprises cyclic carbonates and linear carbonates; The cyclic carbonate is PC (propylene carbonate), and the linear carbonate includes EMC (ethyl methyl carbonate) and DMC (dimethyl carbonate). The mass ratio of PC to EMC and DMC is (14~15): (5.5~6.5): (54~56).

[0026] For example, the mass ratio of PC to EMC and DMC can be any value between 14:5.5:54, 14.5:6:55, 14.65:6:55, 15:6.5:56, or (14~15):(5.5~6.5):(54~56).

[0027] Based on the fact that the formation of solvent-anion pairs in the electrolyte is crucial for ion transport and interfacial stability, and considering the finding that solvent-anion pairing preferentially occurs in DMC rather than EC, the electron-deficient hydrogen (δ-hydrogen) in the solvent molecule... +The positive charge of H is the driving force for the formation of the "solvent-anion pair". Because the methylene (-CH2-) hydrogen atom in the ethyl moiety of the EMC molecule is strongly inductively influenced by the adjacent oxygen, its δ... + The positive charge of hydrogen (H) is significantly stronger than that of the methyl hydrogen in the DMC molecule. Therefore, using a combination of EMC and DMC in the electrolyte can form a stronger and more stable long-range "solvent-anion pair" network than using DMC alone. This enhanced network significantly improves the thermodynamic stability and interfacial compatibility of the electrolyte. Simultaneously, the retention of DMC prevents the network from becoming overly dense due to EMC dominance, thus maintaining a high ion mobility.

[0028] The EMC / DMC mass ratio design follows the scientific principle of the "coordination number rule," achieving superior overall performance by adjusting the solvent ratio. Specifically, this ratio significantly increases the total proportion of low coordination number solvents (LCNS, especially low-viscosity DMC), enhancing the formation of anion-induced solvation structures. Simultaneously, the high proportion of DMC significantly reduces the overall viscosity of the electrolyte, thereby greatly optimizing ionic conductivity.

[0029] When the PC content is within a reasonable range, it helps form a stable and dense solid electrolyte interphase (SEI) film on the graphite anode surface, effectively suppressing further side reactions between the solvent and the anode. Maintaining suitable viscosity ensures that lithium ions have a high migration rate and conductivity in the electrolyte, thereby guaranteeing the battery's rate performance and capacity, avoiding graphite layer peeling caused by solvent co-intercalation, ensuring the stability of the anode structure, and thus extending the battery's cycle life. When the PC content is too high, it can cause PC and lithium ions to co-intercalate at the graphite anode, resulting in graphite layer peeling and instability of the solid electrolyte interphase (SEI) film, thus accelerating battery capacity decay, voltage drop, and thickness expansion. When the PC content is too low, the electrolyte system has a high viscosity, which may lead to an overall high electrolyte viscosity and unsatisfactory ionic conductivity.

[0030] In traditional EC-based electrolytes, EC values ​​are around 0.8V (vs Li / Li). + Nearby, it is reduced to form organic lithium carbonate (such as (CH2OCO2Li)2), which is the main component of the SEI membrane.

[0031] The reduction potential of PC is similar to that of EC (~0.9V), making it an effective film-forming solvent. The decomposition products of PC, such as CH3CH(OCO2Li)CH2(OCO2Li) lithium propylene glycol dicarbonate, constitute the organic matrix framework of the SEI film, ensuring its flexibility. Therefore, the electrolyte of this application can still form a stable SEI film even without EC.

[0032] This application provides a high-temperature, low-gas-producing electrolyte with a simple formulation and superior performance. The electrolyte formulation of this application is simple and does not require the addition of other expensive functional additives (such as VC, FEC, DTD, etc.). The better effect is achieved simply by removing EC and adjusting the PC ratio, which reduces the potential side reactions caused by the decomposition of functional additives, lowers production costs, and improves the consistency and stability of electrolyte batches.

[0033] According to an embodiment of this application, based on the total mass of the electrolyte, the content of PC is 14-15 wt%, the content of EMC is 5.5-6.5 wt%, and the content of DMC is 54-56 wt%.

[0034] With a PC content within the aforementioned range, the low-temperature performance of the electrolyte can be effectively improved. Specifically, PC has a melting point of -48.8°C, while EC has a melting point of 36.4°C; PC's melting point is lower than EC's. Electrolytes containing EC rapidly become viscous or even solidify at low temperatures, while PC-based electrolytes retain their fluidity. Moreover, PC has a lower viscosity than EC. Therefore, the electrolyte of this application can maintain good fluidity and ion mobility in low-temperature environments, which helps maintain the battery's low-temperature conductivity.

[0035] For example, the PC content in the electrolyte is 14 wt%, 14.5 wt%, 14.65 wt%, 15 wt%, or any value between 14 and 15 wt%; the EMC content in the electrolyte is 5.5 wt%, 6 wt%, 6.5 wt%, or any value between 5.5 and 6.5 wt%; and the DMC content in the electrolyte is 54 wt%, 55 wt%, 56 wt%, or any value between 54 and 56 wt%.

[0036] According to embodiments of this application, the electrolyte further includes lithium salt; The lithium salt includes LiPF6 (lithium hexafluorophosphate). The decomposition products of lithium salt LiPF6 during cycling (such as Li...) x PF y O z The participation of LiF in the construction of SEI films helps to enhance the stability of SEI films and improve their ionic conductivity.

[0037] According to an embodiment of this application, the lithium salt content in the electrolyte is 14-15 wt%. For example, the lithium salt content in the electrolyte is 14 wt%, 14.5 wt%, 15 wt%, or any value between 14 and 15 wt%.

[0038] According to embodiments of this application, the electrolyte further includes additives, which include at least one of FEC, LiPO2F2 (lithium difluorophosphate), TMSP (tris(trimethylsilane)phosphate), LiDFOB (lithium difluorooxalate borate), TPP (triphenyl phosphate), and PST (1,3-propenesulfonate lactone).

[0039] According to embodiments of this application, the additive content in the electrolyte is 5-12.5 wt%. For example, the additive content in the electrolyte is 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, 10 wt%, 10.5 wt%, 11 wt%, 11.5 wt%, 12 wt%, 12.5 wt%, or any value between 5 and 12.5 wt%.

[0040] According to embodiments of this application, the content of FEC (fluoroethylene carbonate) in the electrolyte is 5-10 wt%; the reduction potential of FEC (~1.2V) is higher than that of PC and EC, therefore FEC will preferentially undergo reduction decomposition reaction. The formation of a LiF-rich interface layer on the graphite anode surface helps to improve the stability of the solid electrolyte interphase (SEI) film.

[0041] For example, the content of FEC in the electrolyte is 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt%, 8wt%, 8.5wt%, 9wt%, 9.5wt%, 10wt%, or any value between 5-10wt%.

[0042] The content of LiPO2F2 in the electrolyte is 0-0.5wt%; for example, the content of LiPO2F2 in the electrolyte is 0, 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, or any value between 0-0.5wt%.

[0043] The TMSP content in the electrolyte is 0-0.5 wt%; for example, the TMSP content in the electrolyte is 0, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or any value between 0 and 0.5 wt%.

[0044] The content of LiDFOB in the electrolyte is 0-0.5 wt%; for example, the content of LiDFOB in the electrolyte is 0, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or any value between 0 and 0.5 wt%.

[0045] The TPP content in the electrolyte is 0-0.5 wt%; for example, the TPP content in the electrolyte is 0, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or any value between 0 and 0.5 wt%.

[0046] The content of PST in the electrolyte is 0-0.5 wt%. For example, the content of PST in the electrolyte is 0, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or any value between 0 and 0.5 wt%.

[0047] This application also provides a lithium-ion battery, including the electrolyte described above.

[0048] According to embodiments of this application, the lithium-ion battery further includes a positive electrode and a negative electrode; The positive electrode includes a positive electrode active material, which is LiNi. x Co y Mn z L( 1-x-y-z O2, wherein L includes at least one of Al, Sr, Mg, Ti, Ca, Zr, Zn, Si, and Fe, 0.9 ≤ x < 1, 0 <y≤1,0≤z<1,0<x+y+z≤1。

[0049] In some embodiments, the positive electrode active material is LiNi 0.9 Co 0.05 Mn 0.05 O2 and LiNi 0.93 Co 0.05 Mn 0.02 O2 is mixed in a mass ratio of 70:30.

[0050] In some embodiments, the negative electrode includes a negative electrode active material, which includes a composite material of pre-lithiated silicon oxide and graphite.

[0051] In some embodiments, the lithium-ion battery further includes a separator, the separator including a base film and a coating layer located on at least one side of the base film; The base membrane includes any one of polyethylene (PE) membrane, polypropylene (PP) membrane, and composite membrane formed of polyethylene (PE) membrane and polypropylene (PP) membrane. The composite membrane includes stacked PP membrane and PE membrane, or the composite membrane includes stacked PP membrane, PE membrane and PP membrane.

[0052] In some embodiments, the coating layer comprises Al2O3.

[0053] This application also provides an electrical device, including the lithium-ion battery described above.

[0054] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0055] Example 1 Example 1 provides an electrolyte comprising the following components: PC = 14.65 wt%, EMC = 6 wt%, DMC = 55 wt%, FEC = 8 wt%, LiPO2F2 = 0.5 wt%, TMSP = 0.5 wt%, LiDFOB = 0.5 wt%, TPP = 0.5 wt%, PST = 0.35 wt%, and LiPF6 = 14 wt%.

[0056] Comparative Example 1 The difference between Comparative Example 2 and Example 1 is that the PC in Example 1 is replaced with EC of the same mass. Everything else is the same as Example 1.

[0057] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that 14.65 wt% of PC in Example 1 was replaced with 8.65 wt% of EC and 6 wt% of PC. Everything else was the same as in Example 1.

[0058] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the PC content is 29.65 wt% and the DMC content is 40 wt%. Everything else is the same as in Example 1.

[0059] The electrolytes of Example 1 and Comparative Examples 1-3 were assembled into batteries under the same conditions. Specifically, the following steps were included: LiNi... 0.9 Co 0.05 Mn 0.05 O2 and LiNi 0.93 Co 0.05 Mn 0.02 O2 was mixed at a mass ratio of 70:30 to obtain the positive electrode active material. This material was then mixed with conductive carbon black and the binder polyvinylidene fluoride, and dispersed in N-methyl-2-pyrrolidone to obtain the positive electrode slurry. The slurry was uniformly coated onto both sides of an aluminum foil. After drying, rolling, and vacuum drying, aluminum leads were welded using an ultrasonic welder to obtain the positive electrode plate.

[0060] A pre-lithiated silica and graphite composite material, conductive carbon black, styrene-butadiene rubber binder, and carboxymethyl cellulose are mixed in an appropriate ratio and dispersed in deionized water to obtain a negative electrode slurry. The negative electrode slurry is coated on both sides of a copper foil, dried, calendered, and vacuum dried, and then nickel leads are welded using an ultrasonic welder to obtain a negative electrode plate.

[0061] A ceramic membrane (9-micron base film + 2-micron Al2O3 ceramic layer) with Al2O3 coated on one side is used.

[0062] The prepared positive electrode sheet, separator, and negative electrode sheet are wound on an automatic winding machine to obtain a bare battery. The bare battery is placed in a cylindrical steel shell, and the negative electrode terminal and cover terminal are welded on. The electrolyte prepared in the examples and comparative examples is injected into the dried battery cells, and then sealed, placed, pre-charged, aged, and separated to complete the preparation of the lithium-ion secondary battery (21700-5.3Ah).

[0063] The lithium-ion batteries were tested under the same conditions, and the test results are shown in Table 1 below.

[0064] Table 1. Electrochemical performance test results of the examples and comparative examples.

[0065] From Table 1 and Figure 1 , Figure 2 and Figure 3 As can be seen, in the cyclic test at 45°C, Example 1 showed CID flip after 1256 cycles (capacity retention = 71.04%); Comparative Example 1 showed CID flip after 1167 cycles (capacity retention = 73.01%); Comparative Example 2 showed CID flip after 1253 cycles (capacity retention = 71.34%); and Comparative Example 3 showed CID flip after 695 cycles (capacity retention = 69.93%).

[0066] It can be seen that under high-temperature cycling conditions of 45℃, the electrolyte of this application can significantly reduce the amount of gas evolution, extend the number of CID flip cycles, and maintain excellent cycling performance and impedance stability.

[0067] In the 60°C cycling test, Example 1 showed CID flip after 416 cycles (capacity retention = 83.18%), Comparative Example 1 showed CID flip after 285 cycles (capacity retention = 88.98%), Comparative Example 2 showed CID flip after 331 cycles (capacity retention = 88.25%), and Comparative Example 3 showed CID flip after 352 cycles (capacity retention = 84.20%).

[0068] Compared with Comparative Example 1 (conventional EC-containing formulation), the electrolyte of Example 1, after 200 cycles at 45°C (100% SOC, 0.5C / 1C), showed a 9.29% decrease in internal pressure (from 0.323 MPa to 0.293 MPa).

[0069] Compared to Comparative Example 1 (conventional EC-containing formulation), the electrolyte of Example 1 under high-temperature cycling conditions at 60°C (2.75-4.15V, 0.5C / 1C) had a CID flip-off delay of 131 cycles.

[0070] Comparing the EIS and DRT results of the battery before and after 200 cycles in Example 1. The semicircle (R) in the high-frequency region of the Nyquist plot. SEI ) and R in DRT SEI The peak remained stable after 200 cycles with minimal increase. The stable, low-growth interfacial impedance directly demonstrates the stability of the SEI film structure during cycling.

[0071] In Example 1, the battery achieved an average coulombic efficiency of 87% during the first week of pre-charging (comparable to commercial EC-based electrolytes), indicating the formation of an effective SEI film. During subsequent long-term cycling, the coulombic efficiency remained consistently above 70%. This high and stable coulombic efficiency implies a stable SEI film and minimal side reactions.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0073] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the foregoing claims, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. An electrolyte, characterized in that, Includes solvents, said solvents including cyclic carbonates and linear carbonates; The cyclic carbonate is PC, and the linear carbonate includes EMC and DMC; The mass ratio of PC to EMC and DMC is (14~15): (5.5~6.5): (54~56).

2. The electrolyte according to claim 1, characterized in that, Based on the total mass of the electrolyte, the content of PC is 14~15wt%, the content of EMC is 5.5~6.5wt%, and the content of DMC is 54~56wt%.

3. The electrolyte according to claim 1, characterized in that, The electrolyte also includes lithium salt; The lithium salt includes LiPF6.

4. The electrolyte according to claim 3, characterized in that, The lithium salt content in the electrolyte is 14~15 wt%.

5. The electrolyte according to claim 1, characterized in that, The electrolyte also includes additives, which include at least one of FEC, LiPO2F2, TMSP, LiDFOB, TPP, and PST.

6. The electrolyte according to claim 5, characterized in that, The additive is present in the electrolyte at a concentration of 5-12.5 wt%.

7. The electrolyte according to claim 5, characterized in that, The FEC content in the electrolyte is 5-10 wt%; And / or, the content of LiPO2F2 in the electrolyte is 0-0.5 wt%; And / or, the TMSP content in the electrolyte is 0-0.5 wt%; And / or, the content of LiDFOB in the electrolyte is 0-0.5 wt%; And / or, the TPP content in the electrolyte is 0-0.5 wt%; And / or, the content of PST in the electrolyte is 0-0.5 wt%.

8. A lithium-ion battery, characterized in that, Includes the electrolyte according to any one of claims 1-7.

9. The lithium-ion battery according to claim 8, characterized in that, The lithium-ion battery also includes a positive electrode and a negative electrode; The positive electrode includes a positive electrode active material, which is LiNi. x Co y Mn z L( 1-x-y-z O2, wherein L includes at least one of Al, Sr, Mg, Ti, Ca, Zr, Zn, Si, and Fe, 0.9 ≤ x < 1, 0 <y≤1,0≤z<1,0<x+y+z≤1。 10. An electrical-related device, characterized in that, Including the lithium-ion battery as described in claim 8 or 9.

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