Electrolyte, lithium ion battery and electric device

Abstract

The application provides an electrolyte, a lithium ion battery and a power utilization device, the electrolyte comprising an additive, the additive comprising a compound shown in formula I: by adopting the additive, the self-extinguishing time of the electrolyte can be reduced, the safety performance of the battery is improved, and the electrochemical performance of the battery is not affected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to an electrolyte, a lithium ion battery and a power utilization device. BACKGROUND

[0002] In recent years, environmental pollution and depletion of fossil energy have become increasingly serious, and human demand for new energy is becoming more and more urgent. The development of new energy cannot be separated from energy storage devices. At present, the most widely used energy storage device is a lithium ion battery, which has the advantages of high energy density, long cycle life, high power density, and small environmental pollution, and is not only widely used in portable electronic devices, but also gradually becomes the main power energy of electric vehicles. However, in recent years, there have been many reports of fires and even explosions caused by power batteries, and the safety problem of lithium ion batteries has attracted widespread attention. The main reason for such accidents is the thermal runaway caused by exothermic reaction under misuse conditions, and improving the safety of electrolyte is an important means to improve the safety of battery.

[0003] The current high-safety electrolyte mainly optimizes the selection, design and optimization of functional electrolyte additives of the main salt of the electrolyte. The principle of the current related technical solutions is to block the follow-up reaction after the battery generates heat, and to shorten the electrolyte combustion time, but it cannot reduce the heat generation of the battery and reduce the probability of battery thermal runaway, which is limited for improving the safety of the battery. In addition, the use of flame-retardant additives often requires a large amount of addition to achieve the effect of flame retardation, which will significantly increase the impedance and seriously affect the performance of the battery.

[0004] Therefore, the high-safety electrolyte related technology still needs to be improved. SUMMARY

[0005] The present application aims to at least partially solve one of the technical problems in the related art. To this end, the present application provides an electrolyte with excellent safety, a lithium ion battery and a power utilization device.

[0006] In a first aspect of the present application, an electrolyte is provided. According to an embodiment of the present application, the electrolyte comprises an additive, and the additive comprises a compound represented by Formula I:

[0007]

[0008] wherein R1 is selected from any one of H, F, alkyl, fluoroalkyl, alkoxy and fluoroalkoxy;

[0009] each L1 is independently selected from any one of -O-R2, -B-R3, -N-R4R5;

[0010] R2, R3, R4, R5are each independently selected from any one of optionally substituted alkyl, optionally substituted haloalkyl, optionally substituted alkoxy, optionally substituted haloalkoxy and optionally substituted phenyl; the substituents on the above groups are each independently selected from at least one of alkyl, haloalkyl, alkoxy, haloalkoxy, phenyl, oxygen-containing heterocycle, nitrogen-containing heterocycle and sulfur-containing heterocycle; the halogen in the haloalkyl, haloalkoxy is each independently selected from at least one of F, Cl and Br.

[0011] By using the above-mentioned additive, the self-extinguishing time of the electrolyte can be reduced, the thermal stability of the electrolyte can be improved, the safety performance of the battery can be improved, and the electrochemical performance of the battery is basically not negatively affected. Specifically, the non-flammable additive obtained by using the phosphazene monomer containing unsaturated double bonds in the above-mentioned additive greatly reduces the safety risk of causing fire. In summary, the above-mentioned electrolyte of the present application can efficiently conduct lithium ions, can generate a uniform and dense SEI film with high ion conductivity on the negative electrode, has a wide electrochemical window, and has excellent safety performance.

[0012] According to an embodiment of the present application, R1is selected from H, F, C 1～6 alkyl, C 1～6 fluoroalkyl, C 1～6 alkoxy and C 1～6 fluoroalkoxy; R2, R3, R4, R5are each independently selected from any one of optionally substituted C 1～6 alkyl, optionally substituted C 1～6 haloalkyl, optionally substituted C 1～6 alkoxy, optionally substituted C 1～6 haloalkoxy and optionally substituted phenyl; the substituents on the above groups are each independently selected from at least one of C 1～6 alkyl, C 1～6 haloalkyl, C 1～6 alkoxy, C 1～6 haloalkoxy, phenyl, oxygen-containing heterocycle, nitrogen-containing heterocycle and sulfur-containing heterocycle.

[0013] According to an embodiment of the present application, R1is selected from C 1～6 alkyl; each L1is each independently selected from any one of -O-R2, -N-R4R5; R2, R4, R5are each independently selected from C 1～6 alkyl, C 1～6 haloalkyl.

[0014] According to an embodiment of the present application, the above-mentioned additive can include at least one of the following compounds:

[0015]

[0016] Specifically, the above specific compound is used to reduce the self-extinguishing time of the electrolyte, improve the electrochemical performance of the battery, and better inhibit the high-temperature gas production of the battery. Meanwhile, the compound is easy to obtain.

[0017] According to the embodiments of the present application, the mass percentage of the additive in the electrolyte is 1% to 10%, and specifically, it can be 0.2% to 2%. Within the above content range, the flammability of the electrolyte can be effectively reduced, and the self-extinguishing time of the electrolyte can be reduced. Meanwhile, the battery impedance will not be increased due to the relatively large amount of addition, and the battery performance will not be severely affected.

[0018] According to the embodiments of the present application, the electrolyte further comprises an organic solvent, and the organic solvent comprises ethylene carbonate. The mass percentage of the ethylene carbonate in the electrolyte is 10% to 22%, and preferably 14% to 18%. By optimizing the type and ratio of the organic solvent, the heat production of the battery can be effectively reduced, and thus the probability of thermal runaway of the battery can be reduced. In combination with the above additive, the flammability can be reduced while reducing the probability of thermal runaway, and the self-extinguishing time of the electrolyte can be further reduced. Meanwhile, the battery performance will not be affected. The electrolyte is suitable for the electrolyte of a high-energy-density and high-safety hybrid chemical system battery, and can effectively improve the safety problems such as the byproduct reaction heat and the explosion of the battery cell when the battery experiences thermal runaway.

[0019] According to the embodiments of the present application, the organic solvent further comprises at least one of propylene carbonate, dimethyl carbonate, fluorinated ethylene carbonate, diethyl carbonate, methyl ethyl carbonate, dimethyl carbonate, and fluorinated diethyl carbonate. The above solvents have better solvation, which is beneficial to optimizing the battery performance. Meanwhile, the above solvents have better lithium ion transmission performance, and thus the lithium ion battery using the electrolyte has better electrochemical performance.

[0020] According to the embodiments of the present application, the mass percentage of the organic solvent in the electrolyte is 60% to 85%.

[0021] According to the embodiments of the present application, the electrolyte further comprises an electrolyte salt, and the electrolyte salt comprises at least one of lithium bis(trifluoromethylsulfonyl)imide, lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide, lithium perchlorate, lithium difluoro(oxalato)borate, lithium bis(oxalato)borate, lithium difluorophosphate, lithium difluoro(dioxalato)phosphate, and lithium tetrafluoroborate. Thus, better ion transmission performance, electrical conductivity, stability, and compatibility with electrode materials can be provided, and thus the lithium ion battery using the electrolyte has better electrochemical performance.

[0022] According to the embodiments of the present application, the mass percentage of the electrolyte salt in the electrolyte is 10% to 20%. Thus, the ion transmission performance, electrical conductivity, stability, and compatibility with electrode materials of the electrolyte are all better.

[0023] In a second aspect, the present application provides a lithium ion battery. According to embodiments of the present application, the lithium ion battery comprises the electrolyte as described above. The lithium ion battery has low heat generation, low risk of thermal runaway, and excellent thermal stability and safety due to the poor flammability and short self-extinguishing time of the electrolyte.

[0024] In a third aspect, the present application provides an electric device. According to embodiments of the present application, the electric device comprises the lithium ion battery as described above. The electric device has all the features and advantages of the lithium ion battery as described above, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a structural schematic diagram of an electrolyte self-extinguishing time testing device of the present application. DETAILED DESCRIPTION

[0026] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0027] In a first aspect, the present application provides an electrolyte. According to embodiments of the present application, the electrolyte comprises an additive, wherein the additive comprises a compound represented by Formula I:

[0028]

[0029] wherein R1 is selected from any one of H, F, alkyl, fluoroalkyl, alkoxy and fluoroalkoxy;

[0030] each L1 is independently selected from any one of -O-R2, -B-R3, -N-R4R5;

[0031] each of R2, R3, R4 and R5 is independently selected from any one of optionally substituted alkyl, optionally substituted haloalkyl, optionally substituted alkoxy, optionally substituted haloalkoxy and optionally substituted phenyl; each of the substituents on the above groups is independently selected from at least one of alkyl, haloalkyl, alkoxy, haloalkoxy, phenyl, oxygen-containing heterocycle, nitrogen-containing heterocycle and sulfur-containing heterocycle; and each of the halogens in the haloalkyl and haloalkoxy is independently selected from at least one of F, Cl and Br.

[0032] By using the additive, the self-extinguishing time of the electrolyte can be reduced, the electrochemical performance of the battery can be improved, and the cost of the battery can be reduced. Meanwhile, the additive has the effect of inhibiting the production of gas at high temperature of the battery, further improving the safety performance of the battery. Specifically, the non-flammable additive obtained by using the phosphazene monomer containing an unsaturated double bond greatly reduces the safety risk of causing fire. In summary, the electrolyte has the effects of efficiently conducting lithium ions, generating a uniform and dense SEI film with high ion conductivity on the negative electrode, having a wide electrochemical window, and having excellent safety performance.

[0033] According to an embodiment of the present application, R1 is selected from H, F, C 1～6 alkyl, C 1～6 fluoroalkyl, C 1～6 alkoxy, and C 1～6 fluoroalkoxy;

[0034] R2, R3, R4, R5 are each independently selected from one of optionally substituted C 1～6 alkyl, optionally substituted C 1～6 haloalkyl, optionally substituted C 1～6 alkoxy, optionally substituted C 1～6 haloalkoxy, and optionally substituted phenyl, the substituents on the above groups are each independently selected from one of C 1～6 alkyl; C 1～6 haloalkyl; C 1～6 alkoxy; C 1～6 haloalkoxy, phenyl, oxygen-containing heterocycle, nitrogen-containing heterocycle, and sulfur-containing heterocycle.

[0035] According to an embodiment of the present application, R1 is selected from C 1～6 alkyl; each L1 is independently selected from one of -O-R2, -N-R4R5; R2, R4, R5 are each independently selected from one of C 1～6 alkyl; C 1～6 haloalkyl.

[0036] According to an embodiment of the present application, the additive can include at least one of the following compounds:

[0037]

[0038] Specifically, by using the specific compounds, the effects of reducing the self-extinguishing time of the electrolyte, improving the electrochemical performance of the battery, and inhibiting the production of gas at high temperature of the battery are better, and the compounds are easy to obtain and have low cost.

[0039] According to the embodiment of the present application, the mass percentage of the additive in the electrolyte is 1% to 10%, specifically 0.2% to 2%, for example, 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%, and the like. Within the above content range, the flammability of the electrolyte can be effectively reduced, the self-extinguishing time of the electrolyte is reduced, and the battery impedance is not increased due to the large amount of addition, which does not seriously affect the battery performance.

[0040] According to the embodiment of the present application, the electrolyte further comprises an organic solvent, the organic solvent comprises ethylene carbonate, and the mass percentage of the ethylene carbonate in the electrolyte is 10% to 22%, preferably 14% to 18%. For example, it can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, and the like. By optimizing the type and proportion of the organic solvent, the heat generation of the battery can be effectively reduced, thereby reducing the probability of battery thermal runaway. In combination with the above-mentioned additive, the flammability can be reduced while reducing the probability of thermal runaway, the self-extinguishing time of the electrolyte is further reduced, and the battery performance is basically not affected. The electrolyte is suitable for electrolyte of high-energy-density and high-safety hybrid chemical system battery, and can effectively improve the safety problems such as side reaction heat generation and cell explosion of the electrolyte when the battery is in thermal runaway.

[0041] According to the embodiment of the present application, the organic solvent further comprises at least one of propylene carbonate, dimethyl carbonate, fluoroethylene carbonate, diethyl carbonate, methyl ethyl carbonate, dimethyl carbonate, and fluoro-diethyl carbonate. The above-mentioned solvents have better solvation, which is beneficial to optimizing the battery performance, and have better lithium ion transmission performance, thereby making the lithium ion battery using the electrolyte have better electrochemical performance.

[0042] According to the embodiment of the present application, the mass percentage of the organic solvent in the electrolyte is 60% to 85%, specifically 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, and the like.

[0043] According to embodiments of this application, the electrolyte further includes an electrolyte salt, which includes at least one selected from lithium bis(trifluoromethanesulfonyl)imide, lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide, lithium perchlorate, lithium difluorooxalate borate, lithium bis(oxalate borate), lithium difluorophosphate, lithium difluorodioxalate phosphate, and lithium tetrafluoroborate. This provides superior ion transport performance, suitable conductivity, stability, and compatibility with electrode materials, resulting in lithium-ion batteries using this electrolyte exhibiting superior electrochemical performance.

[0044] According to embodiments of this application, the electrolyte salt has a mass percentage content of 10% to 20% in the electrolyte, specifically such as 10%, 11%, 2%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc. Therefore, the electrolyte exhibits superior ion transport performance, conductivity, stability, and compatibility with electrode materials.

[0045] In a second aspect, this application provides a lithium-ion battery. According to an embodiment of this application, the lithium-ion battery includes the electrolyte described above. This lithium-ion battery generates low heat, has a low risk of thermal runaway, and the electrolyte exhibits poor flammability and a short self-extinguishing time, thus possessing excellent thermal stability and safety.

[0046] It is understood that, in addition to the electrolyte mentioned above, the lithium-ion battery may also include an electrode assembly and an outer packaging. The electrode assembly and the electrolyte are contained in the outer packaging. The electrode assembly may include a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. Specifically, it may be a stacked electrode assembly or a wound electrode assembly.

[0047] The positive electrode sheet may include a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector. The positive electrode film layer includes a positive active material, a conductive agent, and a binder.

[0048] The positive electrode active material includes, but is not limited to, lithium transition metal oxides and / or lithium phosphates with an olivine structure. Specifically, lithium transition metal oxides include lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides (such as NCM333, NCM523, NCM211, NCM622, NCM811), and lithium nickel cobalt aluminum oxides (such as LiNi). 0.85 Co 0.15 Al 0.05 O2) or combinations thereof; lithium phosphates with olivine structures, including but not limited to lithium iron phosphate (such as LiFePO4), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium manganese iron phosphate (such as LiMn)x Fe 1-x PO4, 0 < x < 1), at least one of a lithium iron manganese phosphate and a composite material of lithium iron manganese phosphate and carbon.

[0049] The positive electrode conductive agent can include one or more of super P, conductive graphite, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers, and embodiments of the present application are not limited thereto.

[0050] The positive electrode binder can include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyacrylic acid (PAA), polyvinyl alcohol (PVA), ethylene-vinyl acetate copolymer (EVA), styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC), sodium alginate (SA), polymethacrylic acid (PMA), and carboxymethyl chitosan (CMCS).

[0051] The positive electrode current collector can employ a metal foil or a composite current collector. For example, as the metal foil, an aluminum foil can be employed. The composite current collector can include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0052] In some embodiments, the negative electrode tab includes a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector, the negative electrode film layer including a negative electrode active material.

[0053] The negative electrode current collector can employ a metal foil or a composite current collector. For example, as the metal foil, a copper foil can be employed. The composite current collector can include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector can be formed by forming a metal material (such as copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0054] The negative electrode active material can include one or more of a carbon-based material, a silicon-based material, a tin-based material, and lithium titanate. The carbon-based material can include one or more of graphite (such as artificial graphite, natural graphite, etc.), soft carbon, and hard carbon. The silicon-based material can include one or more of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can include one or more of elemental tin, a tin oxide compound, and a tin alloy.

[0055] The negative electrode film layer can include a negative electrode binder. As an example, the negative electrode binder can include one or more of styrene butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS), without being limited thereto in this embodiment.

[0056] The negative electrode film layer can further include a negative electrode conductive agent. As an example, the negative electrode conductive agent can include one or more of super P, conductive graphite, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers, without being limited thereto in this embodiment.

[0057] It can be understood that the specific type of the battery is not particularly limited, and can be a primary battery or a secondary battery. The shape of the battery can be a cylindrical battery, a square battery, or any other shape of battery, etc. According to the outer packaging, the battery can be a hard-shell battery, a soft-pack battery, etc.

[0058] In a third aspect, the present application provides a use electric device. According to an embodiment of the present application, the use electric device includes the lithium ion battery described above. The use electric device has all the features and advantages of the lithium ion battery described above, which will not be repeated here.

[0059] According to an embodiment of the present application, the specific type of the use electric device is not particularly limited. As an example, the use electric device can include a mobile device (such as a mobile phone, a notebook computer, etc.), an electric vehicle (such as 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 and a satellite, an energy storage system, etc., but is not limited thereto.

[0060] Embodiments of the present application will be described in detail below.

[0061] Embodiment 1

[0062] Preparation of electrolyte: EC was weighed according to 12% of the total electrolyte mass, and the remaining solvent was supplemented by DEC and EMC, and uniformly mixed to obtain an organic solvent. LiPF6 required for preparing an electrolyte with a lithium salt concentration of about 1M was weighed, and the LiPF6 was slowly added to the organic solvent, fully dissolved, and then 5wt% of compound 1 was added, continuously stirred until dissolved, and prepared into a lithium ion battery electrolyte. The mass ratio of the electrolyte formula is shown in Table 1.

[0063] Preparation of soft-pack battery: the negative electrode surface density of the graphite negative electrode material was 180 g m -2 , and the compacted density was 1.56 g m -3 ; the positive electrode material was selected as lithium iron phosphate, and the positive electrode surface density was 390 g m-2 The positive electrode sheet, the separator, and the negative electrode sheet are stacked in order with the separator between the positive electrode sheet and the negative electrode sheet to obtain a bare battery cell. The bare battery cell is placed in an aluminum plastic film package, and the electrolyte prepared above is injected into the dried battery cell, which is left to stand at room temperature, thereby completing the preparation of the lithium ion soft package battery.

[0064] Examples 2-11

[0065] The same as Example 1, and the specific differences are shown in Table 1.

[0066] Comparative Examples 1-3

[0067] The same as Example 1, and the specific differences are shown in Table 1.

[0068] Table 1

[0069]

[0070]

[0071] Performance detection:

[0072] 1. Battery cycle performance test: the battery after formation is charged at a current of 0.5C to 3.8V under constant current and constant voltage, the cut-off current of constant voltage charging is 0.05C, and then discharged at a current of 0.5C to 2.0V, and the capacity retention rate test result is shown in Table 2.

[0073] 2. Self-extinguishing time test: the electrolyte in each example and comparative example is used to measure the self-extinguishing time using the electrolyte self-extinguishing device shown in Figure 1 The diameter of the ball is 0.3-0.5cm, and the amount of electrolyte absorbed is 0.05-0.10g. The time from burning to extinguishing per unit weight of electrolyte is recorded, i.e. the recording unit of self-extinguishing time is s·g -1 .

[0074] Table 2

[0075]

[0076] According to the data in Table 2, after using the additive of the present application, the battery performance is flat, and the performance difference of each group is very small, which indicates that the electrolyte in the present application does not significantly affect the cycle performance of the battery.

[0077] As can be seen from Table 2, when the EC content is reduced from 22% (Comparative Example 2) to 12%, the self-extinguishing time is significantly reduced (Comparative Example 1), and further reduced after adding the flame-retardant additive (Example 1). Compared with Comparative Example 2, the self-extinguishing time is reduced by 5% TTFP, but is still lower than that of Example, which proves that the additive compound 1 in Example 1 is more effective in reducing the self-extinguishing time compared with TTFP.

[0078] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. Furthermore, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples, without contradiction.

[0079] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and the person skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. An electrolyte, characterized by, The additive comprises a compound shown in Formula I: Formula I wherein R1is selected from any one of H, F, alkyl, fluoroalkyl, alkoxy and fluoroalkoxy; each L1is independently selected from any one of -O-R2, -B-R3, -N-R4R5; R2, R3, R4, R5are each independently selected from any one of optionally substituted alkyl, optionally substituted haloalkyl, optionally substituted alkoxy, optionally substituted haloalkoxy and optionally substituted phenyl; the substituents on R2, R3, R4, R5are each independently selected from at least one of alkyl, haloalkyl, alkoxy, haloalkoxy, phenyl, oxygen-containing heterocycle, nitrogen-containing heterocycle and sulfur-containing heterocycle; the halogen in haloalkyl, haloalkoxy is each independently selected from at least one of F, Cl and Br.

2. The electrolyte according to claim 1, characterized in that, R1is selected from H, F, C 1~6 alkyl, C 1~6 fluoroalkyl, C 1~6 alkoxy and C 1~6 fluoroalkoxy; R2, R3, R4, R5 are each independently selected from the group consisting of optionally substituted C 1~6 alkyl, optionally substituted C 1~6 haloalkyl, optionally substituted C 1~6 alkoxy, optionally substituted C 1~6 haloalkoxy, and optionally substituted phenyl, the substituents on R2, R3, R4, R5 are each independently selected from the group consisting of C 1~6 alkyl, C 1~6 haloalkyl, C 1~6 alkoxy, C 1~6 haloalkoxy, phenyl, oxygen-containing heterocycle, nitrogen-containing heterocycle, and sulfur-containing heterocycle.

3. The electrolyte of claim 1, wherein R1is selected from C 1~6 alkyl; each L1is independently selected from any one of -O-R2, -N-R4R5; R2, R4, R5are each independently selected from C 1~6 alkyl, C 1~6 any of the halogenated alkyl groups.

4. The electrolyte of claim 1, wherein The additive comprises at least one of the following compounds: 1 2。 5. The electrolyte of claim 1, wherein The mass percentage content of the additive is 1% to 10% based on the total mass of the electrolyte.

6. The electrolyte according to claim 5, characterized in that The mass percentage content of the additive is 0.2% to 2% based on the total mass of the electrolyte.

7. The electrolyte of claim 1, wherein The organic solvent further comprises at least one of propylene carbonate, dimethyl carbonate, fluoroethylene carbonate, diethyl carbonate, methyl ethyl carbonate, dimethyl carbonate, fluoro-diethyl carbonate.

8. The electrolyte of claim 7, wherein, The mass percentage content of the organic solvent is 60% to 85% based on the total mass of the electrolyte.

9. The electrolyte of claim 7, wherein, The electrolyte salt further comprises at least one of lithium bis-trifluoromethanesulfonylimide, lithium hexafluorophosphate, lithium bisfluorosulfonylimide, lithium perchlorate, lithium difluoro(oxalato)borate, lithium bis(oxalato)borate, lithium difluorophosphate, lithium difluoro-di(oxalato)phosphate, lithium tetrafluoroborate.

10. The electrolyte of claim 9, wherein, The mass percentage content of the electrolyte salt is 10% to 20% based on the total mass of the electrolyte.

11. The electrolyte of claim 1, wherein, The electrolyte comprises any one of claims 1 to 12.

12. The electrolyte of claim 11, wherein, The lithium ion battery comprises claim 13.

13. A lithium-ion battery, characterized by, ​ 14. An electrical device, characterized by ​

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