Electrolyte, battery and electric device

Abstract

The embodiment of the present application provides electrolyte, a battery and a power utilization device, the electrolyte comprises a lithium salt, a first additive and a second additive, the lithium salt comprises lithium hexafluorophosphate, the second additive is lithium fluorosulfonate, and the first additive has a structure as shown in formula (1). The first additive and the second additive synergistically form an organic-inorganic composite CEI film on the positive electrode, and at the same time, an inorganic SEI film with high ion conductivity is formed on the negative electrode, the CEI film and the SEI film can reduce the side reaction between the electrode and the electrolyte, and then reduce the destruction of the electrode surface structure and the decomposition of the electrolyte, improve the cycle performance of the battery; and the inorganic SEI film with high ion conductivity can improve the transmission rate of conductive ions, and then improve the power performance of the battery, so that the battery can have better cycle performance and power performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to an electrolyte, a battery and a power utilization device. BACKGROUND

[0002] In recent years, with the transformation of global energy structure, secondary batteries such as lithium ion batteries and sodium ion batteries have become the core technology in the fields of energy storage and mobile energy due to their cyclic charge-discharge characteristics.

[0003] However, in the related art, the electrolyte of the battery is prone to side reactions with the electrode during multiple charge-discharge cycles, causing the surface structure of the electrode to be gradually damaged, and thus leading to rapid capacity decay of the battery and deterioration of the cycle performance of the battery. Meanwhile, the ion conductivity of the traditional electrolyte is limited, and ions cannot be quickly transported during charge-discharge of the battery, thereby reducing the power performance of the battery. The battery cannot have both good cycle performance and power performance, and further improvement is needed. SUMMARY

[0004] Embodiments of the application provide an electrolyte, a battery and a power utilization device, which are intended to at least partially solve the aforementioned technical problems.

[0005] In a first aspect, embodiments of the application provide an electrolyte, the electrolyte comprising a lithium salt, a first additive and a second additive, the lithium salt comprising lithium hexafluorophosphate, the second additive being lithium fluorosulfate, and the first additive having a structure as shown in the following formula (1):

[0006] Formula (1).

[0007] In an embodiment, the mass ratio of the first additive to the second additive is (0.5-8):1.

[0008] In an embodiment, the mass percentage of the first additive in the electrolyte is 0.05%-2%; and / or

[0009] the mass percentage of the second additive in the electrolyte is 0.05%-2%.

[0010] In an embodiment, the mass percentage of the first additive in the electrolyte is 0.1%-1.5%; and / or

[0011] the mass percentage of the second additive in the electrolyte is 0.1%-1%.

[0012] In an embodiment, the electrolyte further comprises a lithium salt and / or a solvent.

[0013] In an embodiment, the mass percentage of the lithium salt in the electrolyte is 10%-15%.

[0014] In an embodiment, the solvent includes at least one of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, propylene carbonate, ethylene carbonate, ethyl acetate, propyl acetate, methyl propionate, methyl acetate, ethyl propionate, propyl propionate, ethyl butyrate, methyl propyl carbonate, gamma-butyrolactone, and gamma-valerolactone.

[0015] In a second aspect, the embodiments of the present application also provide a battery comprising the electrolyte as described above.

[0016] The embodiments of the present application have the following beneficial effects:

[0017] The embodiments of the present application provide an electrolyte. The electrolyte includes a lithium salt, a first additive, and a second additive. The lithium salt includes lithium hexafluorophosphate. The second additive is lithium fluorosulfate. The first additive has a structure as shown in formula (1). The first additive is preferentially subjected to an electrochemical oxidation reaction at a positive electrode due to a high oxidation potential. A benzene ring structure of the first additive is subjected to oxidative dehydrogenation polymerization to form a polyaniline phenyl derivative. A composite cathode electrolyte interface film (CEI film) containing inorganic matter and the phenyl derivative is constructed. The phenyl derivative significantly improves flexibility and mechanical strength of the CEI film. The positive electrode active material lattice stability is maintained through mechanical support. The electrolyte contact is reduced and high-temperature gas production is inhibited. The organic reinforced CEI film effectively makes up for the positive electrode film forming defects (poor flexibility and weak mechanical support) caused by the insufficient oxidation stability of lithium fluorosulfate. At the same time, the first additive has a reduction decomposition tendency at a negative electrode. Sulfur / f luorine species (such as FSI - derivative) of the first additive generates Li2S (lithium sulfide), Li3N (lithium nitride), and other high-impedance inorganic matter under the catalysis of LiPF6 (lithium hexafluorophosphate) hydrolysis products. The inorganic matter may damage the uniformity of a solid electrolyte interface film (SEI film) and degrade ion conduction. The sulfonate (-SO3 - ) of lithium fluorosulfate reduces the lithium ion desolvation energy barrier through strong coordination competition. The low reduction potential of lithium fluorosulfate is prior to the decomposition products of LiPF6 and the first additive at the negative electrode. A dense inorganic SEI film skeleton mainly composed of lithium sulfite and lithium fluoride is quickly formed. The process inhibits the reduction decomposition of the first additive through electron competition and reduces the doping of the decomposition products of the first additive by using the dense SEI physical barrier.

[0018] The first additive and the second additive cooperatively realize bidirectional defect compensation. The first additive overcomes the positive electrode protection short board of lithium fluorosulfate. Lithium fluorosulfate reduces the risk of negative electrode damage of the first additive. The CEI film and the SEI film cooperatively inhibit electrode-electrolyte side reactions and structural damage, significantly improving the cycle performance. The negative electrode high-ionic-conductivity SEI film accelerates ion transmission to improve the power performance. Finally, the cycle and power performance are cooperatively optimized. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person skilled in the art without creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation described herein is only used to illustrate and explain the present application, and is not used to limit the present application. In the present application, the orientation words such as “upper” and “lower” generally refer to the upper and lower in the actual use or working state of the device; and “inner” and “outer” refer to the outline of the device.

[0020] In the related art, the battery cannot have good cycle performance and power performance at the same time, and needs to be further improved.

[0021] The electrolyte provided by the embodiments of the present application includes a lithium salt, a first additive and a second additive. The lithium salt includes lithium hexafluorophosphate. The second additive is lithium fluorosulfate. The first additive has a structure as shown in the following formula (1):

[0022] Formula (1).

[0023] In the present embodiment, the electrolyte includes a first additive and a second additive. The second additive has a sulfonate ion, and the first additive has a structure as shown in formula (1). The first additive preferentially undergoes an electrochemical oxidation reaction at the positive electrode due to a high oxidation potential. The benzene ring structure of the first additive is oxidatively dehydrogenated and polymerized to form a phenyl derivative such as polyaniline, thereby constructing a composite cathode electrolyte interface film (CEI film) containing inorganic matter and a phenyl derivative. The phenyl derivative significantly improves the flexibility and mechanical strength of the CEI film, maintains the stability of the positive active material lattice through mechanical support, reduces the contact of the electrolyte, and inhibits gas production at high temperature. The organic reinforced CEI film effectively makes up for the positive electrode film forming defects (poor flexibility and weak mechanical support) caused by the insufficient oxidation stability of lithium fluorosulfate. At the same time, the first additive has a reduction decomposition tendency at the negative electrode. The sulfur / f luorine-containing species (such as FSI - derivative) of the first additive generates high-impedance inorganic matter such as Li2S (lithium sulfide) and Li3N (lithium nitride) under the catalysis of LiPF6 (lithium hexafluorophosphate) hydrolysis products, which may damage the uniformity of the solid electrolyte interface film (SEI film) and degrade the ion conduction. The sulfonate (-SO3 -) by strong coordination competition to reduce the lithium ion desolvation energy barrier, its low reduction potential is prior to LiPF6 and the first additive decomposition product in the negative electrode reduction, quickly form a dense inorganic SEI film skeleton with lithium sulfite and lithium fluoride as the main ion conductive; the process inhibits the first additive reduction decomposition by electron competition, and reduces the first additive decomposition product doping by using the dense SEI physical barrier.

[0024] The first additive and the second additive achieve bidirectional defect compensation: the first additive overcomes the positive electrode protection short board of lithium fluorosulfonate, and lithium fluorosulfonate reduces the risk of negative electrode damage of the first additive. The CEI film and the SEI film cooperate to inhibit the electrode-electrolyte side reaction and structural damage, and significantly improve the cycle performance; the negative electrode high-conductive ion SEI film accelerates ion transmission to improve the power performance, and finally realizes the cooperative optimization of cycle and power performance.

[0025] In an embodiment, the mass ratio of the first additive and the second additive is (0.5-8):1. Alternatively, the mass ratio of the first additive and the second additive can be any one of 0.5:1, 1:1, 3:1, 5:1, 7:1, 8:1, or a range between any two of them, which is not limited herein.

[0026] In the present embodiment, when the mass ratio of the first additive and the second additive is less than 0.5:1, it is easy to cause the content of the first additive to be too small, the content of the second additive to be too much, the content of the phenyl derivative such as polyaniline in the positive electrode CEI film to be insufficient, the compactness of the CEI film to decrease, and the CEI film to present a porous structure (the porosity of the CEI film >40%). Anions in the electrolyte can easily embed into the positive electrode lattice through the pores of the CEI film to induce a layered structure phase change, and reduce the diffusion coefficient (the diffusion coefficient of the conductive ion decreases to 10 -12 cm 2 / s) and transmission rate of the conductive ion; at the same time, the excessive second additive competes for electrons at the positive electrode interface, and the SO3 2- radicals can catalyze solvent decomposition, the battery gas production increases (the battery gas production increases by 2 times), and transition metal dissolution is accelerated, and the dissolved ions can migrate to the negative electrode to catalyze SEI film decomposition, resulting in battery swelling (the battery swelling rate is more than 5%). When the mass ratio of the first additive and the second additive is greater than 8:1, it is easy to cause the content of the first additive to be too much, the content of the second additive to be too small, and the effect of the second additive on inhibiting the reduction reaction of the first additive in the negative electrode to be unsatisfactory. A large amount of phenyl derivatives generated by the reduction reaction of the first additive in the negative electrode region easily form cross-linked polymers (the molecular weight of the cross-linked polymer >5000 Da), block the conductive ion transmission channel (the pore size of the transmission channel <1 nm), and increase the SEI film interface impedance (the interface impedance increases from 20Ω·cm 2 to 100Ω·cm 2) and the content of inorganic components such as sulfide oxides and lithium fluoride in the SEI film is reduced (the mass percentage of lithium fluoride in the SEI film is reduced to less than 30%), which easily leads to accelerated growth of lithium dendrites (the length of lithium dendrites is increased to 10 μm), the electronic tunneling effect causes continuous reduction of electrolyte to produce gas (the gas production rate is 0.3 mL / Ah / cycle), and the battery is expanded (the thickness expansion rate of the battery is more than 8%). Therefore, by setting the mass ratio of the first additive to the second additive to (0.5-8): 1, the battery can have better cycle performance and power performance.

[0027] In this embodiment, when the mass ratio of the first additive to the second additive is set to (0.5-8): 1, in the positive electrode CEI film, the mass percentage of lithium fluoride in the CEI film is 30%-50%, and the mass percentage of polyaniline in the CEI film is 50%-70%. In the negative electrode SEI film, the mass percentage of lithium fluoride in the SEI film is 70%-90%, and the mass percentage of lithium sulfite in the SEI film is 10%-30%. Among them, lithium fluoride and lithium sulfite can improve the conductivity of the interface film and reduce the interface impedance, polyaniline can improve the flexibility and mechanical strength of the CEI film, reduce the contact between the electrolyte and the electrode material, and inhibit the decomposition of the electrolyte to produce gas under high temperature working conditions. The first additive and the second additive can synergistically achieve dynamic balance of the interface film, and the battery has better cycle performance and power performance. After the battery is cycled at a high voltage of 4.4 V for 1000 cycles, the capacity retention rate is >85%, the gas production amount is <0.05 mL / Ah, and the interface impedance is stably at 20 Ω·cm 2 within.

[0028] Among them, the content of lithium sulfite, lithium fluoride and polyaniline in the CEI film and the SEI film can be analyzed by X-ray photoelectron spectroscopy. The analysis depth is about 5 nm-10 nm, and the content of lithium sulfite, lithium fluoride and polyaniline and other components in the interface film is determined by peak fitting.

[0029] In an embodiment, the mass percentage of the first additive in the electrolyte is 0.05%-2%. Alternatively, the mass percentage of the first additive in the electrolyte can be any one of 0.05%, 0.1%, 0.5%, 1%, 1.3%, 1.6%, 2% or a range between any two of them, which is not limited herein. Preferably, the mass percentage of the first additive in the electrolyte is 0.1%-1.5%.

[0030] In this embodiment, by setting the mass percentage of the first additive in the electrolyte to 0.05%-2%, it can be ensured that the first additive can form a high-ionic-conductivity inorganic SEI film skeleton on the negative electrode and inhibit the side reaction of the second additive on the negative electrode; at the same time, the oxidation of the second additive to generate SO3 2-The free radicals, in turn, reduce the side reactions generated by the second additive in the battery.

[0031] In an embodiment, the mass percentage of the second additive in the electrolyte is 0.05%-2%. Alternatively, the mass percentage of the second additive in the electrolyte can be any one of 0.05%, 0.1%, 0.5%, 1%, 1.3%, 1.6%, 2%, or a range between any two of them, without limitation. Preferably, the mass percentage of the second additive in the electrolyte is 0.1%-1%.

[0032] In the present embodiment, the mass percentage of the second additive in the electrolyte is set to 0.05%-2%, which can ensure that the second additive can form a dense CEI film containing phenyl derivatives such as polyaniline at the positive electrode, reducing the contact of the electrolyte with the electrode material; at the same time, reducing the reduction reaction of the first additive at the negative electrode region to generate phenyl derivatives, in turn, reducing the blockage of the conductive ion transmission channel of the SEI film by the cross-linked polymers formed between the phenyl derivatives, ensuring that the SEI film has a lower interface impedance.

[0033] In an embodiment, the first additive and the second additive can be purchased directly or prepared by oneself. Specifically, the first additive is N-phenyl bisfluorosulfone imide, and N-phenyl bisfluorosulfone imide (CAS No.: 1622206-83-0) and lithium fluorosulfonate can be purchased directly.

[0034] In an embodiment, the electrolyte further includes a lithium salt, and the mass percentage of the lithium salt in the electrolyte is 10%-15%. Alternatively, the mass percentage of the lithium salt in the electrolyte can be any one of 10%, 11%, 12%, 13%, 14%, 15%, or a range between any two of them, without limitation. In the present embodiment, the mass percentage of the lithium salt in the electrolyte is set in the above range, which can make the electrolyte have a better ion conductivity.

[0035] In an embodiment, the electrolyte further includes a solvent, and the solvent includes at least one of dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, propylene carbonate, ethylene carbonate, ethyl acetate, propyl acetate, methyl propionate, methyl acetate, ethyl propionate, propyl propionate, ethyl butyrate, methyl propyl carbonate, γ-butyrolactone, and γ-valerolactone.

[0036] The present application also provides a battery including the electrolyte as described above. In the present embodiment, the battery can include a lithium ion battery or a sodium ion battery, and the type of the battery is not limited herein.

[0037] The application also provides a power consumption device comprising the electrolyte or the battery.

[0038] The above scheme is further described in combination with specific embodiments. The embodiments of the application are described in detail as follows:

[0039] Embodiment 1

[0040] 1. Preparation of the electrolyte

[0041] In an argon atmosphere glove box (water content <1 ppm, oxygen content <1 ppm), ethylene carbonate (EC), methyl ethyl carbonate (EMC) and dimethyl carbonate (DMC) are mixed uniformly according to a mass ratio of 30:40:30 to obtain a solvent, and then lithium hexafluorophosphate (LiPF6), a first additive and a second additive are added to the solvent, dissolved and mixed uniformly to obtain an electrolyte; wherein:

[0042] The mass percentage of lithium hexafluorophosphate (LiPF6) in the electrolyte is 12.5%;

[0043] The mass percentage of the first additive in the electrolyte is 1%;

[0044] The second additive is lithium fluorosulfonate, and the mass percentage of the second additive in the electrolyte is 0.5%;

[0045] The rest is the solvent.

[0046] 2. Preparation of the positive electrode sheet

[0047] Lithium iron phosphate, conductive agent CNT (conductive carbon nanotube), conductive agent SP (conductive carbon black) and binder PVDF (polyvinylidene fluoride) are uniformly dispersed in NMP (N-methyl pyrrolidone) solvent according to a mass ratio of 96:0.5:1.0:2.5, and after stirring in a vacuum environment for a period of time, a positive electrode slurry with a solid content of 60% is obtained. The positive electrode slurry is uniformly coated on both surfaces of an aluminum foil, the electrode sheet is dried, and then rolled according to a rolling density of 2.45 g / cm 3 The positive electrode sheet is finally die-cut into a specified size.

[0048] 3. Preparation of the negative electrode sheet

[0049] The graphite, SP (conductive carbon black), binder CMC (carboxymethyl cellulose) and binder SBR (styrene-butadiene rubber emulsion) were uniformly dispersed in deionized water at a mass ratio of 96.0:1.0:1.0:2.0, and a mixed uniform negative electrode slurry with a solid content of 60% was obtained after sufficient stirring in a vacuum environment. The negative electrode slurry was uniformly coated on both surfaces of the copper foil, the electrode piece was dried, and the electrode piece was pressed to a thickness of 0.1 mm at a pressure of 1.6 g / cm 3 The compaction density was rolled, and finally the negative electrode piece was die-cut to a specified size

[0050] 4. Preparation of a lithium ion battery

[0051] The positive electrode piece, the polyethylene separator and the negative electrode piece prepared above were stacked in order, with the separator between the positive electrode piece and the negative electrode piece to play a role of isolation, to assemble the stacked battery. The positive tab was connected to the positive electrode piece, and the negative tab was connected to the negative electrode piece, to obtain an electrode assembly. The electrode assembly was placed in an aluminum foil packaging bag, and the positive tab and the negative tab were led out from the internal space of the aluminum foil packaging bag to the external space of the aluminum foil packaging bag. Vacuum drying was performed at 85°C for 48 hours, the electrolyte prepared above was injected, and the injection coefficient was 3.0 g / Ah. After vacuum packaging, formation, aging, and other processes, a lithium ion battery was obtained. The upper limit voltage of the formation was 3.9V, the formation temperature was 45°C, and the standing time of the formation was 2 hours. The aging temperature was 45°C, and the standing time of the aging was 24 hours. The capacity was 0.1C charged to 4.35V, and then left for 5 minutes. Then, the capacity was 0.1C discharged to 3.0V, and then the above steps were repeated 3 times to obtain the lithium ion battery.

[0052] The preparation method of the lithium ion battery of Example 2-25 and Comparative Example 1-4 was the same as that of Example 1, except that the electrolyte composition was different, as shown in Table 1.

[0053] Table 1

[0054]

[0055] Test method

[0056] The lithium ion batteries prepared in Examples 1-25 and Comparative Examples 1-4 were tested for electrochemical performance, and the specific method was as follows:

[0057] (1) High-temperature cycle performance test:

[0058] The lithium ion battery was subjected to 1500 cycles of charge and discharge at 1C current at 45°C, and the capacity retention rate (%) = (1500th discharge capacity / 1st discharge capacity) x 100%.

[0059] (2) Low-temperature discharge performance test method:

[0060] One lithium ion battery was placed in an environment at 25°C, and charged at a current of 1C to an upper limit cutoff voltage, and the cutoff current was 0.05C. Then, the battery was discharged at a current of 1C to a lower limit cutoff voltage, and the discharge capacity at room temperature at this time was recorded as C1. Then, the battery was again charged at a current of 1C to an upper limit cutoff voltage, and the cutoff current was 0.05C. The fully charged battery was placed in a low-temperature constant-temperature oven at -20±2°C for 5h, and then discharged at a current of 0.5C to a lower limit cutoff voltage, and the discharge capacity at this time was recorded as C2. The capacity retention rate = (C2 / C1) x 100%.

[0061] (3) High-temperature storage for 30 days capacity retention rate

[0062] The 1C discharge capacity of the lithium ion battery was recorded as C0, and then the battery was placed in a 60°C oven for storage for 30 days. After the storage time ended, the lithium ion battery was taken out and cooled to room temperature, and discharged at a current of 1C to 2V at 25°C. The discharge capacity was recorded as C1. The calculation method of the high-temperature storage capacity retention rate is as follows:

[0063] High-temperature storage capacity retention rate (%) = (discharge capacity after storage C1 / 1C discharge capacity C0 during capacity grading) x 100%.

[0064] The test results are shown in Table 2 below:

[0065] Table 2

[0066]

[0067] As can be seen from the test results in Table 2, compared with Comparative Examples 1-4, the capacity retention rate after 30 days of high-temperature storage, the capacity retention rate after 1500 cycles at 45°C, and the low-temperature discharge capacity retention rate of the lithium ion batteries prepared in Examples 1-25 are all improved. It is shown that by adding the first additive and the second additive to the electrolyte, the second additive is lithium fluorosulfonate, and the first additive has a structure as shown in formula (1). The first additive can preferentially undergo an electrochemical oxidation reaction at the positive electrode to form a cathode electrolyte interface film (CEI film) with inorganic matter and phenyl derivatives such as polyaniline, reducing the contact between the electrolyte and the electrode material and inhibiting the decomposition of the electrolyte under high-temperature working conditions. The second additive can quickly occupy the active sites of the negative electrode and preferentially form an inorganic SEI film skeleton with high ionic conductivity mainly composed of lithium sulfite and lithium fluoride on the surface of the negative electrode, reducing the side reaction between the first additive and the negative electrode. At the same time, the second additive inhibits the reduction reaction of the first additive through electron competition, reducing the influence of the decomposition products of the first additive on the conductivity of the SEI film. The synergistic effect of the first additive and the second additive forms an organic-inorganic composite CEI film at the positive electrode, and at the same time, an inorganic SEI film with high ionic conductivity is formed at the negative electrode. The CEI film and the SEI film can reduce the side reaction between the electrode and the electrolyte, thereby reducing the destruction of the electrode surface structure and the decomposition of the electrolyte, and improving the cycle performance of the battery. The inorganic SEI film with high ionic conductivity can improve the transmission rate of conductive ions, thereby improving the power performance of the battery, so that the battery can have good cycle performance and power performance.

[0068] As can be seen from the comparison of Examples 1-16 and Examples 17-25, setting the mass ratio of the first additive to the second additive to (0.5-8):1 can ensure that the battery has good cycle performance and power performance.

[0069] As can be seen from the comparison of Examples 1-12, Examples 15-16, Example 23, and Example 25, controlling the mass percentage of the first additive in the electrolyte in the range of 0.05%-2% can ensure that the battery has good cycle performance.

[0070] As can be seen from the comparison of Examples 1-12, Examples 13-14, Examples 24-25, controlling the mass percentage of the second additive in the electrolyte in the range of 0.05%-2% can ensure that the battery has good cycle performance.

[0071] The above has carried out the detailed introduction to the embodiment of the application, the principle and implementation mode of the application have been described by applying specific examples in this paper, the above embodiment description is only used for helping understanding the method of the application and its core idea; at the same time, for the person skilled in the art, according to the idea of the application, there will be changes in specific implementation mode and application range, and the above is described, the content of the specification should not be understood as the limitation of the application.

Claims

1. An electrolyte, characterized in that: The electrolyte includes a lithium salt, a first additive, and a second additive. The lithium salt includes lithium hexafluorophosphate, the second additive is lithium fluorosulfonate, and the structure of the first additive is shown in the following formula (1): Formula (1); The mass ratio of the first additive and the second additive is (0.5-8): 1; The mass percentage of the first additive in the electrolyte is 0.05%-2%; The mass percentage of the second additive in the electrolyte is 0.05%-2%.

2. The electrolyte according to claim 1, characterized in that The mass percentage of the first additive in the electrolyte is 0.1%-1.5%; and / or The mass percentage of the second additive in the electrolyte is 0.1%-1%.

3. The electrolyte according to claim 1 or 2, characterized in that The electrolyte further includes a solvent.

4. The electrolyte according to claim 1, characterized in that The mass percentage of the lithium salt in the electrolyte is 10%-15%.

5. The electrolyte according to claim 3, characterized in that The solvent includes at least one of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, propylene carbonate, ethylene carbonate, ethyl acetate, propyl acetate, methyl propionate, methyl acetate, ethyl propionate, propyl propionate, ethyl butyrate, methylpropyl carbonate, γ-butyrolactone and γ-valerolactone.

6. A battery, characterized in that: The electrolyte comprises the electrolyte according to any one of claims 1 to 5.

7. An electrical device, characterized in that: Comprising the battery according to claim 6.

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