Fluoro-ether and preparation method thereof, electrolyte, battery and electric device

Abstract

The invention discloses fluoro-ether and a preparation method thereof, a refrigerant, an electrolyte, a battery and an electric device. The invention relates to the technical field of batteries, in particular to fluoro-ether and a preparation method thereof, a refrigerant, an electrolyte, a battery and an electric device. The fluoroether has a simple structural formula as shown in R1 [OCH2] n4R2, and at least one of R1 and R2 comprises a group containing fluorine atoms; and n4 is a positive integer of 1-6. And n4 is a positive integer less than 6, so that the voltage endurance and oxidation resistance of the electrolyte can be improved, the viscosity of fluoroether is reduced, the influence on the conductivity of the electrolyte is reduced, and the conductivity of the electrolyte is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to fluoroethers and preparation methods thereof, electrolytes, batteries and electrical devices. Background Art

[0002] Ethers have the characteristics of low viscosity and high ionic conductivity and can be used as alternative solvents in lithium-ion batteries. However, they have poor capacity retention and are prone to dendrite formation during battery cycling. By introducing fluorine atoms into ethers, fluorinated ethers have excellent salt dissolving ability. The introduction of fluorine atoms can effectively reduce the electron cloud density of ether oxygen, thereby improving the oxidative stability of ether molecules, achieving excellent cycling stability in high-voltage lithium metal batteries.

[0003] However, the chain length of fluoroether and the number of fluorine atoms will also affect the viscosity and conductivity of fluoroether and electrolyte, thereby affecting the cycle performance of lithium-ion batteries. Summary of the Invention

[0004] The present application is made in view of the above-mentioned problems, and its purpose is to provide a fluoroether that can provide pressure resistance and antioxidant properties, provide appropriate viscosity, and reduce the impact on the viscosity and conductivity of the electrolyte.

[0005] In order to achieve the above-mentioned objectives, the embodiments of the present application provide a fluoroether and a preparation method thereof, a refrigerant, an electrolyte, a battery and an electrical device.

[0006] In the first aspect, the present invention provides a fluoroether having the following structural formula:

[0007]

[0008] wherein at least one of R1 and R2 comprises a group containing a fluorine atom;

[0009] n4 is a positive integer from 1 to 6.

[0010] Thus, in the technical solution of the embodiment of the present application, the longer the chain length of the carbon chain, the greater the viscosity of the fluoroether. By using n4 as a positive integer less than 6, the viscosity of the fluoroether can be reduced, thereby reducing the effect of the fluoroether added to the electrolyte on the viscosity of the electrolyte, reducing the effect on the conductivity of the electrolyte, and improving the conductive properties of the electrolyte. At the same time, when n4 is greater than 6, the reaction yield of the synthesized fluoroether is too low, the reaction is difficult, and it is not easy to purify, which affects the application of the fluoroether. At the same time, the fluoroether itself has a high viscosity, which makes the viscosity of the electrolyte increase and the conductivity decrease.

[0011] It should be noted that when at least one of R1 and R2 includes a fluorine-containing group, it can be that only R1 includes a fluorine-containing group, while R2 does not; it can also be that only R2 includes a fluorine-containing group, while R1 does not; or it can be that both R1 and R2 include fluorine-containing groups. In some embodiments of the present application, the number of fluorine atoms in the fluorine-containing group can be one or more. In some embodiments of the present application, either R1 or R2 can be a hydrogen atom.

[0012] In any embodiment, the R1 has the structural formula shown in (I), and the R2 has the structural formula shown in (II) or a hydrogen atom:

[0013]

[0014] wherein X1 comprises a methyl group substituted with 1 to 3 fluorine atoms;

[0015] X2 includes a methyl group substituted with 0 to 3 fluorine atoms;

[0016] n1 is a positive integer from 1 to 6;

[0017] n2 is a positive integer from 1 to 6.

[0018] X1 includes a methyl group substituted with 1 to 3 fluorine atoms to obtain a fluoroether substituted with different fluorine atoms. Both n1 and n2 are less than 6, which can improve the activity of the fluoroether, reduce the viscosity of the fluoroether, and reduce the impact on the conductive properties of the electrolyte.

[0019] In any embodiment, n1 is a positive integer from 1 to 3; and / or,

[0020] n2 is a positive integer from 1 to 3.

[0021] Both n1 and n2 are positive integers ranging from 1 to 3, which can further improve the activity of the fluoroether, reduce the viscosity of the fluoroether, and reduce the impact on the conductive properties of the electrolyte.

[0022] In any embodiment, n4 is a positive integer from 1 to 3. When n4 is within this range, raw materials are more readily available, synthesis is easier, and yield is higher. At the same time, the viscosity is appropriate and the effect on the viscosity and conductivity of the electrolyte is small.

[0023] It should be noted that in some embodiments of the present application, when X1 and X2 are both methyl groups substituted with two fluorine atoms, the fluoroether is a fluoroether substituted with multiple fluorine atoms at both ends, which has a suitable viscosity and has less effect on the viscosity and conductivity of the electrolyte.

[0024] In a second aspect, the present invention provides a method for preparing a fluoroether according to the first aspect of the present invention, comprising the following steps:

[0025] Mixing a formaldehyde polymer with at least one fluoroalcohol, adding a catalyst, and reacting to obtain a fluoroether;

[0026] Wherein, the fluoroether has the following structural formula:

[0027]

[0028] wherein at least one of R1 and R2 comprises a group containing a fluorine atom;

[0029] n4 is a positive integer from 1 to 6.

[0030] The preparation method of the fluoroether comprises the following reaction formula:

[0031]

[0032] Fluoroethers are produced by reacting formaldehyde polymers with fluoroalcohols in the presence of a catalyst. This reaction can be carried out at room temperature, under mild conditions, with a simple process and high yield. This can reduce the viscosity of the fluoroether and the electrolyte, minimizing the effect on the electrolyte's conductivity and improving the electrolyte's conductive properties.

[0033] In any embodiment, the step of "mixing a formaldehyde polymer with at least one fluoroalcohol, adding a catalyst, and reacting to obtain a fluoroether" comprises:

[0034] Mixing formaldehyde polymer with at least one fluoroalcohol, adding a catalyst and a molecular sieve, and reacting to obtain a crude fluoroether extract;

[0035] The crude fluoroether extract is washed and filtered, and the filtrate is taken and rectified to obtain the rectified fluoroether.

[0036] By adding catalysts and molecular sieves, the yield of fluoroethers can be increased. At the same time, the water generated during the reaction is removed, so that the reaction moves towards the direction of generating fluoroethers, further increasing the yield of fluoroethers.

[0037] In any embodiment, the molecular sieve includes 4A molecular sieve, which has good water absorption effect and is easy to obtain and inexpensive; and / or,

[0038] The catalyst includes any one of concentrated hydrochloric acid, concentrated sulfuric acid, p-toluenesulfonic acid and p-toluenesulfonic acid. Using any one of the above catalysts can increase the reaction rate, move the reaction toward the formation of fluoroether, and increase the yield of fluoroether; and / or,

[0039] The fluoroalcohol includes at least one of monofluoromethanol, difluoromethanol, trifluoromethanol, 2-fluoroethanol, 2,2-difluoroethanol, 2,2,2-trifluoroethanol, 3-fluoropropanol, 3,3-difluoropropanol, and 3,3,3-trifluoropropanol; and / or,

[0040] The mass ratio of the formaldehyde polymer to the molecular sieve is 1:(3-6). At this mass ratio, the conversion rate of the raw materials can be improved, the yield of the final product fluoroether can be increased, and the concentration of the reactants can be maintained, thereby improving the reaction efficiency. Optionally, the mass ratio of the formaldehyde polymer to the molecular sieve is 1:(4-5).

[0041] In any embodiment, the formaldehyde polymer has the structural formula shown in (III), and the fluoroalcohol has the structural formula shown in at least one of (IV) and (V).

[0042]

[0043] Wherein, n3 is a positive integer greater than or equal to 1;

[0044] X1 includes a methyl group substituted with 1 to 3 fluorine atoms;

[0045] X2 includes a methyl group substituted with 0 to 3 fluorine atoms;

[0046] n1 is a positive integer from 1 to 6;

[0047] n2 is a positive integer from 1 to 6.

[0048] By using methyl groups substituted with 1 to 3 fluorine atoms and methyl groups substituted with 0 to 3 fluorine atoms, fluoroethers with different fluorine atom substitutions can be obtained. Fluorinated ethers with different numbers of fluorine atoms have different electronegativity. Different numbers of fluorine in the electrolyte correspond to different complexing abilities. Using methyl groups substituted with 1 to 3 fluorine atoms and methyl groups substituted with 0 to 3 fluorine atoms can improve the conductivity of the electrolyte while reducing the impact on the viscosity of the electrolyte.

[0049] In any embodiment, the molar ratio of the formaldehyde polymer to the fluoroalcohol is 1:(1-10). At this molar ratio, the yield of the fluoroether can be increased; alternatively, the molar ratio of the formaldehyde polymer to the fluoroalcohol is 1:(2-5); and / or,

[0050] The mass ratio of the formaldehyde polymer to the catalyst is (5-25):1. At this mass ratio, the catalytic performance of the catalyst can be improved, while the probability of side reactions and by-products can be reduced, and the yield of fluoroether can be increased; optionally, the mass ratio of the formaldehyde polymer to the catalyst is (10-15):1.

[0051] In any embodiment, in the step of "mixing the formaldehyde polymer with at least one fluoroalcohol, adding a catalyst, and reacting to obtain a fluoroether":

[0052] The reaction temperature is 0-100° C. At this reaction temperature, the probability of side reactions can be reduced, by-products can be reduced, the yield of fluoroether can be increased, and the efficiency of the reaction can be improved; optionally, the reaction temperature is 50-80° C.; and / or,

[0053] The reaction time is 1 to 24 hours. Under this reaction time, the probability of side reactions can be reduced, by-products can be reduced, the yield of fluoroether can be increased, and the reaction efficiency can be improved. Optionally, the reaction time is 6 to 12 hours.

[0054] In a third aspect, an embodiment of the present application provides an electrolyte, comprising the fluoroether of the first aspect of the present application or the fluoroether prepared by the preparation method of the fluoroether of the second aspect of the present application.

[0055] In a fourth aspect, an embodiment of the present application provides a battery comprising the electrolyte of the third aspect of the present application.

[0056] In a fifth aspect, an embodiment of the present application proposes an electrical device comprising the battery according to the fourth aspect of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 Schematic diagram of a secondary battery according to one embodiment of the present application.

[0058] Figure 2 yes Figure 1 FIG. 1 is an exploded view of a secondary battery according to an embodiment of the present application.

[0059] Figure 3 Schematic diagram of a battery module according to one embodiment of the present application.

[0060] Figure 4 Schematic diagram of a battery pack according to one embodiment of the present application.

[0061] Figure 5 yes Figure 4 An exploded view of a battery pack according to an embodiment of the present application is shown.

[0062] Figure 6 FIG. 1 is a schematic diagram of an electrical device using a secondary battery according to an embodiment of the present application as a power source.

[0063] Figure 7 This is the carbon spectrum of Example 9 of this application.

[0064] Figure 8 This is the hydrogen spectrum of Example 9 of the present application.

[0065] Figure 9This is the fluorine spectrum of Example 9 of the present application.

[0066] Figure 10 This is the carbon spectrum of Example 10 of this application.

[0067] Figure 11 This is the hydrogen spectrum of Example 10 of the present application.

[0068] Figure 12 This is the fluorine spectrum of Example 10 of the present application.

[0069] Figure 13 This is the carbon spectrum of Example 8 of this application.

[0070] Figure 14 This is the hydrogen spectrum of Example 8 of the present application.

[0071] Figure 15 This is the fluorine spectrum of Example 8 of the present application.

[0072] Description of reference numerals:

[0073] 1 battery pack; 2 upper case; 3 lower case; 4 battery module; 5 secondary battery; 51 shell; 52 electrode assembly; 53 top cover assembly. DETAILED DESCRIPTION

[0074] The following specifically discloses embodiments of the fluoroether preparation method, electrolyte, battery, and electrical device of the present application. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially identical structures may be omitted. This is to avoid unnecessary length in the following description and to facilitate understanding by those skilled in the art. Furthermore, the drawings and the following description are provided to facilitate a thorough understanding of the present application by those skilled in the art and are not intended to limit the subject matter recited in the claims.

[0075] " range " disclosed in the present application is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of special range. The scope limited in this way can be to include end value or not include end value, and can be arbitrarily combined, that is, any lower limit can form a range with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for specific parameters, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range value 1 and 2 are listed, and if the maximum range value 3,4 and 5 are listed, then the following range can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise specified, the numerical range " ab " represents the abbreviation of any real number combination between a and b, wherein a and b are all real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0076] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0077] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0078] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), indicating that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0079] Ethers have the characteristics of low viscosity and high ionic conductivity and can be used as alternative solvents in lithium-ion batteries. However, they have poor capacity retention and are prone to dendrite formation during battery cycling. By introducing fluorine atoms into ethers, fluorinated ethers have excellent salt dissolving ability. The introduction of fluorine atoms can effectively reduce the electron cloud density of ether oxygen, thereby improving the oxidative stability of ether molecules, achieving excellent cycling stability in high-voltage lithium metal batteries.

[0080] However, the chain length of fluoroether and the number of fluorine atoms will also affect the viscosity and conductivity of fluoroether and electrolyte, thereby affecting the cycle performance of lithium-ion batteries.

[0081] Consequently, research on fluoroethers has been intensive. For example, one method for producing fluoroethers involves reacting a raw material, such as an alcohol or phenol, with a fluoroolefin in the presence of a catalyst, with or without a solvent, to produce a fluoroether reaction solution. The raw material is then concentrated to obtain a concentrated solution and a clear solution, which is then purified and separated to produce the fluoroether product. However, these fluoroethers significantly affect the viscosity and conductivity of the electrolyte, making their application difficult.

[0082] Based on this, the present application provides a fluoroether and its preparation method, electrolyte, battery and electrical device.

[0083] In the first aspect, the present invention provides a fluoroether having the following structural formula:

[0084]

[0085] wherein at least one of R1 and R2 comprises a group containing a fluorine atom;

[0086] n4 is a positive integer from 1 to 6, and the value of n4 can be 1, 2, 3, 4, 5 or 6.

[0087] Therefore, in the technical solution of the embodiment of the present application, by making n4 a positive integer less than 6, the viscosity of the fluoroether and the electrolyte can be reduced, the impact on the conductivity of the electrolyte can be reduced, and the conductive properties of the electrolyte can be improved. At the same time, when n4 is greater than 6, the reaction yield of the synthesized fluoroether is too low, the reaction is difficult, and purification is difficult, which affects the application of the fluoroether. At the same time, the fluoroether itself has a high viscosity, which increases the viscosity of the electrolyte and reduces the conductivity.

[0088] It should be noted that when at least one of R1 and R2 includes a fluorine-containing group, it can be that only R1 includes a fluorine-containing group, while R2 does not; it can also be that only R2 includes a fluorine-containing group, while R1 does not; or it can be that both R1 and R2 include fluorine-containing groups. In some embodiments of the present application, the number of fluorine atoms in the fluorine-containing group can be one or more. In some embodiments of the present application, either R1 or R2 can be a hydrogen atom.

[0089] In any embodiment, the R1 has the structural formula shown in (I), and the R2 has the structural formula shown in (II) or a hydrogen atom:

[0090]

[0091] wherein X1 comprises a methyl group substituted with 1 to 3 fluorine atoms;

[0092] X2 includes a methyl group substituted with 0 to 3 fluorine atoms;

[0093] n1 is a positive integer from 1 to 6;

[0094] n2 is a positive integer from 1 to 6.

[0095] X1 includes a methyl group substituted with 1 to 3 fluorine atoms to obtain a fluorinated ether with different fluorine atom substitutions. Both n1 and n2 are less than 6, which can improve the activity of the fluorinated ether, reduce the viscosity of the fluorinated ether, and reduce the impact on the conductivity of the electrolyte. The value of X1 can be 1, 2, or 3; the value of X2 can be 0, 1, 2, or 3; the value of n1 can be 1, 2, 3, 4, 5, or 6; and the value of n2 can be 1, 2, 3, 4, 5, or 6.

[0096] In any embodiment, n1 is a positive integer from 1 to 3.

[0097] In any embodiment, n2 is a positive integer from 1 to 3.

[0098] Both n1 and n2 are positive integers ranging from 1 to 3, which can further improve the activity of the fluoroether, reduce the viscosity of the fluoroether, and reduce the impact on the conductive properties of the electrolyte.

[0099] In any embodiment, n4 is a positive integer from 1 to 3, and the value of n4 can be 1, 2, or 3. When n4 is within this range, the raw materials are more readily available, the synthesis is easier, the yield is higher, and at the same time, the viscosity is appropriate, which has little effect on the viscosity and conductivity of the electrolyte.

[0100] It should be noted that in some embodiments of the present application, when X1 and X2 are both methyl groups substituted with two fluorine atoms, the fluoroether is a fluoroether substituted with multiple fluorine atoms at both ends, which has a suitable viscosity and has less effect on the viscosity and conductivity of the electrolyte.

[0101] In a second aspect, the present invention provides a method for preparing a fluoroether according to the first aspect of the present invention, comprising the following steps:

[0102] Mixing a formaldehyde polymer with at least one fluoroalcohol, adding a catalyst, and reacting to obtain a fluoroether;

[0103] Wherein, the fluoroether has the following structural formula:

[0104]

[0105] wherein at least one of R1 and R2 comprises a group containing a fluorine atom;

[0106] n4 is a positive integer from 1 to 6.

[0107] The preparation method of the fluoroether comprises the following reaction formula:

[0108]

[0109] Fluoroethers are produced by reacting formaldehyde polymers with fluoroalcohols in the presence of a catalyst. This reaction can be carried out at room temperature, under mild conditions, with a simple process and high yield. This can reduce the viscosity of the fluoroether and the electrolyte, minimizing the effect on the electrolyte's conductivity and improving the electrolyte's conductive properties.

[0110] In any embodiment, the step of "mixing a formaldehyde polymer with at least one fluoroalcohol, adding a catalyst, and reacting to obtain a fluoroether" comprises:

[0111] Mixing formaldehyde polymer with at least one fluoroalcohol, adding a catalyst and a molecular sieve, and reacting to obtain a crude fluoroether extract;

[0112] The crude fluoroether extract is washed and filtered, and the filtrate is taken and rectified to obtain the rectified fluoroether.

[0113] By adding catalysts and molecular sieves, the yield of fluoroethers can be increased. At the same time, the water generated during the reaction is removed, so that the reaction moves towards the direction of generating fluoroethers, further increasing the yield of fluoroethers.

[0114] In any embodiment, the molecular sieve includes 4A molecular sieve, which has good water absorption effect and is easy to obtain and inexpensive as a raw material.

[0115] In any embodiment, the catalyst comprises any one of concentrated hydrochloric acid, concentrated sulfuric acid, and p-toluenesulfonic acid. Using any of these catalysts can increase the reaction rate, shifting the reaction toward the formation of the fluoroether, and improving the yield of the fluoroether. It should be noted that the mass fraction of the concentrated hydrochloric acid can be 36-38%. The mass fraction of the concentrated sulfuric acid can be 97-98%.

[0116] In any embodiment, the fluoroalcohol includes at least one of monofluoromethanol, difluoromethanol, trifluoromethanol, 2-fluoroethanol, 2,2-difluoroethanol, 2,2,2-trifluoroethanol, 3-fluoropropanol, 3,3-difluoropropanol, and 3,3,3-trifluoropropanol.

[0117] In any embodiment, the mass ratio of the formaldehyde polymer to the molecular sieve is 1:(3-6). At this mass ratio, the conversion rate of the raw materials can be improved, the yield of the final product fluoroether can be increased, and the concentration of the reactants can be maintained, thereby improving the reaction efficiency. The mass ratio of the formaldehyde polymer to the molecular sieve can be 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5 or 1:6; optionally, the mass ratio of the formaldehyde polymer to the molecular sieve is 1:(4-5).

[0118] In any embodiment, the formaldehyde polymer has the structural formula shown in (III), and the fluoroalcohol has the structural formula shown in at least one of (IV) and (V):

[0119]

[0120] Wherein, n3 is a positive integer greater than or equal to 1;

[0121] X1 includes a methyl group substituted with 1 to 3 fluorine atoms;

[0122] X2 includes a methyl group substituted with 0 to 3 fluorine atoms;

[0123] n1 is a positive integer from 1 to 6;

[0124] n2 is a positive integer from 1 to 6.

[0125] By using methyl groups substituted with 1 to 3 fluorine atoms and methyl groups substituted with 0 to 3 fluorine atoms, fluoroethers with different fluorine atom substitutions can be obtained. Fluorinated ethers with different numbers of fluorine atoms have different electronegativity. Different numbers of fluorine in the electrolyte correspond to different complexing abilities. Using methyl groups substituted with 1 to 3 fluorine atoms and methyl groups substituted with 0 to 3 fluorine atoms can improve the conductivity of the electrolyte while reducing the impact on the viscosity of the electrolyte.

[0126] In any embodiment, the molar ratio of the formaldehyde polymer to the fluoroalcohol is 1:(1-10). At this molar ratio, the yield of the fluoroether can be increased; the molar ratio of the formaldehyde polymer to the fluoroalcohol can be 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10. Alternatively, the molar ratio of the formaldehyde polymer to the fluoroalcohol is 1:(2-5).

[0127] In any embodiment, the mass ratio of the formaldehyde polymer to the catalyst is (5-25):1. At this mass ratio, the catalytic performance of the catalyst can be improved, while the probability of side reactions and by-products can be reduced, and the yield of fluoroether can be increased. The mass ratio of the formaldehyde polymer to the catalyst can be 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 21:1, 22:1, 23:1, 24:1 or 25:1. Optionally, the mass ratio of the formaldehyde polymer to the catalyst is (10-15):1.

[0128] In any embodiment, in the step of "mixing a formaldehyde polymer with at least one fluoroalcohol, adding a catalyst, and reacting to obtain a fluoroether": the reaction temperature is 0 to 100°C. At this reaction temperature, the probability of side reactions can be reduced, the by-products can be reduced, the yield of the fluoroether can be increased, and the efficiency of the reaction can be improved. The reaction temperature can be 0°C, 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C or 100°C; optionally, the reaction temperature is 50 to 80°C.

[0129] In any embodiment, in the step of "mixing a formaldehyde polymer with at least one fluoroalcohol, adding a catalyst, and reacting to obtain a fluoroether": the reaction time is 1 to 24 hours. Under this reaction time, the probability of side reactions can be reduced, by-products can be reduced, the yield of the fluoroether can be increased, and the efficiency of the reaction can be improved. The reaction time can be 1 hour, 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours or 24 hours; optionally, the reaction time is 6 to 12 hours.

[0130] In a third aspect, an embodiment of the present application provides an electrolyte, comprising the fluoroether of the first aspect of the present application or the fluoroether prepared by the preparation method of the fluoroether of the second aspect of the present application.

[0131] In a fourth aspect, an embodiment of the present application proposes a battery comprising the electrolyte according to the three aspects of the present application.

[0132] In any embodiment, the battery comprises a primary battery or a secondary battery.

[0133] In one embodiment of the present application, a secondary battery is provided. Typically, a secondary battery includes a positive electrode, a negative electrode, an electrolyte, and a separator. During the battery's charge and discharge processes, active ions are intercalated and released between the positive and negative electrodes. The electrolyte conducts ions between the positive and negative electrodes. The separator is positioned between the positive and negative electrodes, primarily preventing a short circuit between the positive and negative electrodes while allowing ions to pass through.

[0134] The positive electrode sheet includes a positive electrode current collector and a positive electrode film layer arranged on at least one surface of the positive electrode current collector.

[0135] As an example, the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive electrode current collector.

[0136] In some embodiments, the positive electrode current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymer material base and a metal layer formed on at least one surface of the polymer material base. The composite current collector may 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 substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0137] In some embodiments, the positive electrode active material may be a positive electrode active material for lithium ion batteries that is well known in the art. As an example, the positive electrode active material may include at least one of the following materials: lithium phosphates containing olivine structure, lithium transition metal oxides and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and its modified compounds. Examples of olivine-structured lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.

[0138] In some embodiments, the positive electrode film layer further includes a binder. As an example, the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), a vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, and a fluorine-containing acrylate resin.

[0139] In some embodiments, the positive electrode film layer further includes a conductive agent, which may include, for example, at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0140] In some embodiments, the positive electrode sheet can be prepared by the following method: the components for preparing the positive electrode sheet, such as the positive electrode active material, the conductive agent, the binder and any other components, are dispersed in a solvent (such as N-methylpyrrolidone) to form a positive electrode slurry; the positive electrode slurry is coated on the positive electrode sheet structure, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained.

[0141] The negative electrode sheet includes a positive electrode current collector and a negative electrode film layer disposed on at least one surface of the positive electrode current collector, wherein the negative electrode film layer includes a negative electrode active material.

[0142] As an example, the negative electrode sheet structure includes a negative electrode current collector having two opposite surfaces in its own thickness direction, and the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector structure.

[0143] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. The composite current collector may include a polymer base layer and a metal layer formed on at least one surface of the polymer base material. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer base material (such as a base material of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0144] In some embodiments, the negative electrode active material may be a negative electrode active material for a battery that is well known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxides, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxides, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0145] In some embodiments, the negative electrode film layer further includes a binder. The binder may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0146] In some embodiments, the negative electrode film layer further includes a conductive agent, which can be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0147] In some embodiments, the negative electrode film layer further includes other additives, such as a thickener (eg, sodium carboxymethyl cellulose (CMC-Na)).

[0148] In some embodiments, the negative electrode sheet can be prepared by the following method: the components for preparing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder and any other components, are dispersed in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on the negative electrode sheet structure, and after drying, cold pressing and other processes, the negative electrode sheet can be obtained.

[0149] The electrolyte conducts ions between the positive and negative electrodes. This application does not specify the type of electrolyte, and the electrolyte can be selected based on the needs. For example, the electrolyte can be liquid, gel, or solid.

[0150] In some embodiments, the electrolyte is an electrolyte solution comprising an electrolyte salt and a solvent.

[0151] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0152] In some embodiments, the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.

[0153] In some embodiments, the electrolyte may further include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, and additives that improve battery high or low temperature performance.

[0154] The electrolyte further comprises the fluoroether according to the first aspect of the present application or the fluoroether prepared by the preparation method of the fluoroether according to the second aspect of the present application.

[0155] In some embodiments, the secondary battery further includes a separator. The present application has no particular limitation on the type of separator, and any known porous separator with good chemical and mechanical stability can be selected.

[0156] In some embodiments, the material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation.

[0157] In some embodiments, the positive electrode sheet, the negative electrode sheet, and the separator may be formed into an electrode assembly by a winding process or a lamination process.

[0158] In some embodiments, the secondary battery may include an outer packaging that can be used to encapsulate the electrode assembly and the electrolyte.

[0159] In some embodiments, the outer packaging of the secondary battery can be a hard shell, such as a hard plastic shell, an aluminum shell, or a steel shell. Alternatively, the outer packaging of the secondary battery can be a soft shell, such as a pouch-type soft shell. The soft shell can be made of plastic, such as polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0160] The present application has no particular restrictions on the shape of the secondary battery, which can be cylindrical, square or any other shape. For example, Figure 1 The secondary battery 5 is a square structure as an example.

[0161] In some embodiments, reference Figure 2 The outer packaging may include a shell 51 and a cover plate 53. The shell 51 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity. The shell 51 has an opening connected to the receiving cavity, and the cover plate 53 can be covered on the opening to close the receiving cavity. The positive electrode sheet, the negative electrode sheet and the isolation membrane can form an electrode assembly 52 through a winding process or a lamination process. The electrode assembly 52 is encapsulated in the receiving cavity. The electrolyte is infiltrated in the electrode assembly 52. The number of electrode assemblies 52 contained in the secondary battery 5 can be one or more, and those skilled in the art can select according to specific actual needs.

[0162] In some embodiments, secondary batteries can be assembled into a battery module. The number of secondary batteries contained in the battery module can be one or more. The specific number can be selected by those skilled in the art according to the application and capacity of the battery module.

[0163] Figure 3 4 is an example of a battery module. Figure 3 In the battery module 4, the plurality of secondary batteries 5 may be arranged in sequence along the length of the battery module 4. Of course, they may also be arranged in any other manner. The plurality of secondary batteries 5 may further be fixed by fasteners.

[0164] Optionally, the battery module 4 may further include a housing having a receiving space, and the plurality of secondary batteries 5 are received in the receiving space.

[0165] In some embodiments, the battery modules described above may also be assembled into a battery pack. The battery pack may contain one or more battery modules, and the specific number may be selected by those skilled in the art based on the application and capacity of the battery pack.

[0166] Figure 4 and Figure 5The battery pack 1 is used as an example. Figure 4 and Figure 5 The battery pack 1 may include a battery box and multiple battery modules 4 disposed in the battery box. The battery box includes an upper box body 2 and a lower box body 3. The upper box body 2 can cover the lower box body 3 and form an enclosed space for accommodating the battery modules 4. The multiple battery modules 4 can be arranged in any manner in the battery box.

[0167] In a fifth aspect, an embodiment of the present application proposes an electrical device comprising the battery according to the fourth aspect of the present application.

[0168] In addition, the present application also provides an electric device, which includes at least one of the secondary battery, battery module, or battery pack provided in the present application. The secondary battery, battery module, or battery pack can be used as a power source for the electric device, and can also be used as an energy storage unit for the electric device. The electric device may include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but is not limited thereto.

[0169] As the electrical device, a secondary battery, a battery module or a battery pack can be selected according to its usage requirements.

[0170] Figure 6 This is an example of an electric device. This device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the high power and high energy density requirements of the secondary battery, a battery pack or battery module can be used.

[0171] Another example device may be a mobile phone, a tablet computer, a notebook computer, etc. Such a device is generally required to be lightweight and thin, and may use a secondary battery as a power source.

[0172] The technical solutions of the present invention are further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0173] The fluoroethers of Examples 1 to 11 of the present application have the parameters shown in Table 1.

[0174]

[0175]

[0176]

[0177] The fluoroethers prepared by the preparation methods of fluoroethers in Examples 12 to 46 were subjected to the following tests: Performance Test

[0178] Purity test: tested by gas chromatography, test conditions: injection temperature 280℃, initial temperature 50℃, heating rate 15℃ / min, final temperature 280℃, injection volume 0.8uL, split ratio 15:1.

[0179] Yield test: Yield = (actual product amount / theoretical product amount) × 100%.

[0180] The test results are shown in Table 2.

[0181] The fluoroethers of Examples 8, 9, and 10 were subjected to nuclear magnetic resonance structural analysis.

[0182] Figure 7 is the carbon spectrum of Example 9, Figure 7 It can be seen that the chemical shift positions 112~116 are the carbon peaks of CHF2 on both sides; the chemical shift at position 96 is the carbon peak of OCH2O in the middle; and the chemical shift at positions 66~67 is the carbon peak of CH2.

[0183] Figure 8 is the hydrogen spectrum of Example 9, Figure 8 It can be seen that the chemical shift positions of 5.8 to 6.0 are the hydrogen peaks of CHF2 on both sides, the chemical shift position of 4.78 is the hydrogen peak of OCH2O in the middle, and the chemical shift position of 3.75 to 3.82 is the hydrogen peak of CH2.

[0184] Figure 9 is the fluorine spectrum of Example 9, Figure 9 It can be seen that the chemical shift position -126 is the fluorine peak of CHF2 on both sides.

[0185] Figure 10 is the carbon spectrum of Example 10, Figure 10 It can be seen that the chemical shift positions 112~116 are the carbon peaks of CHF2 on both sides; the chemical shift at position 92 is the carbon peak of OCH2OCH2O in the middle; and the chemical shift at positions 66~67 is the carbon peak of CH2.

[0186] Figure 11 is the hydrogen spectrum of Example 10, Figure 11 It can be seen that the chemical shift positions of 5.8 to 6.0 are the hydrogen peaks of CHF2 on both sides, the chemical shift position of 4.84 is the hydrogen peak of OCH2OCH2O in the middle, and the chemical shift position of 3.76 to 3.81 is the hydrogen peak of CH2.

[0187] Figure 12 is the fluorine spectrum of Example 10, Figure 12 It can be seen that the chemical shift position of -126 is the fluorine peak of CHF2 on both sides.

[0188] Figure 13 is the carbon spectrum of Example 8, Figure 13 It can be seen that the chemical shift positions 112~116 are the carbon peaks of CHF2 on both sides, the chemical shift position 96 is the carbon peak of OCH2O in the middle, the chemical shift positions 66~67 are the carbon peaks of CH2, and the chemical shift position 55.5 is the carbon peak of CH3.

[0189] Figure 14 is the hydrogen spectrum of Example 8, Figure 14 It can be seen that the chemical shift positions of 5.8 to 6.0 are hydrogen peaks of CHF2 on both sides, the chemical shift position of 4.66 is the hydrogen peak of OCH2O in the middle, the chemical shift position of 3.69 to 3.76 is the hydrogen peak of CH2, and the chemical shift position of 3.38 is the hydrogen peak of CH3.

[0190] Figure 15 is the fluorine spectrum of Example 8, Figure 15 It can be seen that the chemical shift position of -126 is the fluorine peak of CHF2 on both sides.

[0191] As shown in Examples 12 to 47, the reaction of formaldehyde polymers with fluoroalcohols in the presence of a catalyst to produce fluoroethers can be carried out at room temperature, under mild reaction conditions, with a simple reaction process and high yield. This can also reduce the viscosity of the fluoroether and the electrolyte, minimizing the effect on the electrolyte conductivity and improving the conductive properties of the electrolyte.

[0192] The mass ratio of formaldehyde polymer to molecular sieve is 1:(3-6). Under this mass ratio, the conversion rate of raw materials can be improved, the yield of the final product fluoroether can be increased, and the concentration of reactants can be maintained, thereby improving the reaction efficiency.

[0193] The mass ratio of the formaldehyde polymer to the catalyst is (5-25):1. Under this mass ratio, the catalytic performance of the catalyst can be improved, while the probability of side reactions and by-products can be reduced, and the yield of fluoroether can be improved.

[0194] The reaction temperature is 0-100° C., and the reaction time is 1-24 hours, which can reduce the probability of side reactions, reduce by-products, increase the yield of fluoroether, and improve the reaction efficiency.

[0195] The above are only preferred embodiments of the present application and are not intended to limit the scope of the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of the present application.

Claims

1. A fluoroether, characterized in that It has the following simplified structural formula: wherein at least one of R1 and R2 comprises a group containing a fluorine atom; n4 is a positive integer from 1 to 6.

2. The fluoroether according to claim 1, wherein The R1 has the structural formula shown in (I), and the R2 has the structural formula shown in (II) or a hydrogen atom: wherein X1 is a methyl group substituted with 1 to 3 fluorine atoms; X2 is a methyl group substituted with 0 to 3 fluorine atoms; n1 is a positive integer from 1 to 6; n2 is a positive integer from 1 to 6.

3. The fluoroether according to claim 2, wherein n1 is a positive integer from 1 to 3; and / or, n2 is a positive integer from 1 to 3.

4. The fluoroether according to any one of claims 1 to 3, wherein n4 is a positive integer from 1 to 3.

5. A method for preparing a fluoroether according to any one of claims 1 to 4, characterized in that: The following steps are involved: Mixing a formaldehyde polymer with at least one fluoroalcohol, adding a catalyst, and reacting to obtain a fluoroether; Wherein, the fluoroether has the following structural formula: wherein at least one of R1 and R2 comprises a group containing a fluorine atom; n4 is a positive integer from 1 to 6.

6. The method for preparing a fluoroether according to claim 5, wherein: The step of "mixing a formaldehyde polymer with at least one fluoroalcohol, adding a catalyst, and reacting to obtain a fluoroether" comprises: Mixing formaldehyde polymer with at least one fluoroalcohol, adding a catalyst and a molecular sieve, and reacting to obtain a fluoroether crude extract; The crude fluoroether extract is washed and filtered, and the filtrate is taken and rectified to obtain the rectified fluoroether.

7. The method for preparing a fluoroether according to claim 6, wherein: The molecular sieve includes 4A molecular sieve; and / or, The catalyst includes any one of concentrated hydrochloric acid, p-toluenesulfonic acid, concentrated sulfuric acid and p-toluenesulfonic acid; and / or, The fluoroalcohol includes at least one of monofluoromethanol, difluoromethanol, trifluoromethanol, 2-fluoroethanol, 2,2-difluoroethanol, 2,2,2-trifluoroethanol, 3-fluoropropanol, 3,3-difluoropropanol, and 3,3,3-trifluoropropanol; and / or, The mass ratio of the formaldehyde polymer to the molecular sieve is 1:(3-6).

8. The method for preparing a fluoroether according to any one of claims 5 to 7, wherein: The formaldehyde polymer has the structural formula shown in (III), and the fluoroalcohol has the structural formula shown in at least one of (IV) and (V). Wherein, n3 is a positive integer greater than or equal to 1; X1 is a methyl group substituted with 1 to 3 fluorine atoms; X2 is a methyl group substituted with 0 to 3 fluorine atoms; n1 is a positive integer from 1 to 6; n2 is a positive integer from 1 to 6.

9. The method for preparing a fluoroether according to any one of claims 5 to 8, wherein: The molar ratio of the formaldehyde polymer to the fluoroalcohol is 1:(1-10); and / or, The mass ratio of the formaldehyde polymer to the catalyst is (5-25):

1.

10. The method for preparing a fluoroether according to any one of claims 5 to 9, wherein: In the step of "mixing a formaldehyde polymer with at least one fluoroalcohol, adding a catalyst, and reacting to obtain a fluoroether": The reaction temperature is 0 to 100°C; and / or, The reaction time is 1 to 24 hours.

11. An electrolyte, characterized in that: The invention comprises the fluoroether according to any one of claims 1 to 4, or the fluoroether prepared by the method for preparing the fluoroether according to any one of claims 5 to 10.

12. A battery, characterized in that: Comprising the electrolyte as claimed in claim 11.

13. An electrical device, characterized in that: Comprising the battery of claim 12.

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