Fluoroether compound and preparation method thereof, electrolyte, secondary battery and electric device

Abstract

The invention provides a fluoroether compound and a preparation method thereof, an electrolyte, a secondary battery and a power utilization device, the fluoroether compound comprises a structural formula shown in a formula (I): # imgabs0 #, in the formula (I), R1 independently comprises C1-4 alkane, and R2 comprises a single bond or C1-2 alkane. The fluoroether compound provided by the invention has relatively high oxidation stability, and is beneficial to improving the oxidation resistance of the electrolyte and the cycle performance of the battery.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a fluoroether compound and a preparation method thereof, an electrolyte, a secondary battery and an electrical device. Background Art

[0002] Secondary batteries represented by lithium-ion batteries have the characteristics of high capacity and long life, so they are widely used in electronic devices such as mobile phones, laptops, battery cars, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc. As lithium-ion batteries have made great progress, higher requirements have been put forward for their energy density, cycle performance and safety performance. However, the electrolyte of secondary batteries currently has the problem of poor oxidation resistance, resulting in low battery cycle performance. Summary of the invention

[0003] The purpose of the present application is to provide a fluoroether compound and a preparation method thereof, an electrolyte, a secondary battery and an electrical device. The fluoroether compound has high oxidation stability, which is beneficial to improving the antioxidant properties of the electrolyte and the cycle performance of the battery.

[0004] In order to achieve the above-mentioned object, the first aspect of the present application provides a fluoroether compound, which includes the structural formula shown in formula (I):

[0005]

[0006] In formula (I), R 1 Each independently includes C 1～4 Alkanes, R 2 Includes single bonds or C 1～2 of alkanes.

[0007] The fluoroether compound of the structure shown in formula (I) provided in the present application contains two fluorine atoms in its molecule, which can effectively reduce the electron cloud density of the ether oxygen in the fluoroether compound molecule, increase the oxidation potential of the fluoroether compound, and thus improve its oxidation stability.

[0008] In some embodiments of the present application, the fluoroether compound includes one or more of 1,2-diethoxy-1,2-difluoroethane, 1,2-dipropoxy-1,2-difluoroethane, 1,2-dimethoxy-1,2-difluoroethane, 1,2-dibutoxy-1,2-difluoroethane, 1,3-dimethoxy-1,3-difluoropropane, 1,3-diethoxy-1,3-difluoropropane, 1,3-dipropoxy-1,3-difluoropropane, 1,3-dibutoxy-1,3-difluoropropane, 1,4-dimethoxy-1,4-difluorobutane, 1,4-diethoxy-1,4-difluorobutane, 1,4-dipropoxy-1,4-difluorobutane and 1,4-dibutoxy-1,4-difluorobutane;

[0009] Optionally, the fluoroether compound includes one or more of 1,2-diethoxy-1,2-difluoroethane, 1,2-dipropoxy-1,2-difluoroethane, 1,2-dimethoxy-1,2-difluoroethane and 1,2-dibutoxy-1,2-difluoroethane.

[0010] The second aspect of the present application also provides a method for preparing a fluoroether compound, comprising:

[0011] The fluorinating agent is subjected to a substitution reaction with a halogenated ether to prepare a fluoroether compound;

[0012] The fluoroether compound includes the structural formula shown in formula (I):

[0013]

[0014] In formula (I), R 1 Each independently includes C 1～4 Alkanes, R 2 Includes single bonds or C 1～2 of alkanes;

[0015] Wherein, the chemical formula of the fluorinating agent includes MF n , M includes at least one of Na, K, Cs, Sb and H, and n is an integer of 1 to 5;

[0016] The halogenated ether includes the structural formula shown in formula (II):

[0017]

[0018] In formula (II), R 1 Each independently includes C 1～4 Alkanes, R 2 Includes single bonds or C 1～2 Alkanes, X 1 and X 2 Each independently includes one of a chlorine atom, a bromine atom and an iodine atom.

[0019] The above method provided by the present application can directly replace the halogen atom in the halogenated ether with the fluorine atom by allowing the fluorinating agent to undergo a substitution reaction with the halogenated ether, thereby obtaining the fluoroether compound provided by the first aspect of the present application. The method does not involve other intermediate reaction processes, the process route is simple, and the yield and purity of the obtained fluoroether compound are high.

[0020] In some embodiments of the present application, the step of subjecting the fluorinating agent to a substitution reaction with a halogenated ether comprises:

[0021] heat-treating an organic solution containing the fluorinating agent;

[0022] At the heat treatment temperature, allowing the halogenated ether to contact and react with the fluorinating agent to prepare the fluoroether compound;

[0023] Optionally, the organic solution comprises an organic solvent;

[0024] Optionally, the organic solvent includes one or more of acetonitrile, dimethyl carbonate, diethyl carbonate, ethyl acetate, dichloromethane, chloroform, carbon tetrachloride and dimethyl sulfoxide, and may be one or more of acetonitrile, ethyl acetate, dichloromethane and dimethyl sulfoxide.

[0025] In the above steps, by heat-treating the organic solution containing the fluorinating agent and contacting the halogenated ether with the fluorinating agent at the heat treatment temperature, the substitution reaction between the fluorinating agent and the halogenated ether bond can be promoted and the substitution reaction can be carried out more completely.

[0026] In some embodiments of the present application, the fluorinating agent includes one or more of antimony trifluoride, antimony pentafluoride, anhydrous hydrofluoric acid, sodium fluoride, potassium fluoride and cesium fluoride, and can be selected from one or more of antimony trifluoride, antimony pentafluoride, sodium fluoride and potassium fluoride.

[0027] In some embodiments of the present application, the organic solution satisfies at least one of the following conditions:

[0028] (1) The mass ratio of the fluorinating agent to the organic solvent is 1:(0.8-10);

[0029] (2) the organic solution further comprises a phase transfer catalyst;

[0030] Optionally, the mass ratio of the phase transfer catalyst to the organic solvent is (0.003-0.02):1;

[0031] Optionally, the phase transfer catalyst includes one or more of polyether, crown ether, quaternary ammonium salt, tertiary amine and quaternary ammonium base;

[0032] Optionally, the phase transfer catalyst includes one or more of 18-crown-6, 15-crown-5, cyclodextrin, chain polyethylene glycol, benzyltriethylammonium chloride, tetrabutylammonium bromide, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, pyridine and tributylamine;

[0033] Further optionally, the phase transfer catalyst includes 18-crown-6.

[0034] The fluorinating agent and halogenated ether provided as the reaction raw materials in the above method have poor compatibility. Adding the above phase transfer catalyst to the reaction raw materials can make the reaction raw materials mutually soluble and evenly mixed, which is beneficial to promote the reaction and improve the reaction efficiency.

[0035] In some embodiments of the present application, the temperature of the heat treatment is -20°C to 50°C, and can be optionally -10°C to 10°C.

[0036] The heat treatment temperature is within the above range, which is beneficial to increasing the reaction rate and reducing the generation of by-products; it is also beneficial to reducing the polymerization reaction that may occur between the reaction raw materials and improving the performance and yield of the product fluoroether compound.

[0037] In some embodiments of the present application, the halogenated ether includes 1,2-diethoxy-1,2-dichloroethane, 1,2-dipropoxy-1,2-dichloroethane, 1,2-dimethoxy-1,2-dichloroethane, 1,2-dibutoxy-1,2-dichloroethane, 1,3-dimethoxy-1,3-dichloropropane, 1,3-diethoxy-1,3-dichloropropane, 1,3-dipropoxy-1,3-dichloropropane, 1,3-dibutoxy-1,3-dichloropropane, 1,4-dimethoxy- 1,4-dichlorobutane, 1,4-diethoxy-1,4-dichlorobutane, 1,4-dipropoxy-1,4-dichlorobutane, 1,4-dibutoxy-1,4-dichlorobutane, 1,2-diethoxy-1,2-dibromoethane, 1,2-dipropoxy-1,2-dibromoethane, 1,2-dimethoxy-1,2-dibromoethane, 1,2-dibutoxy-1,2-dibromoethane, 1,3-dimethoxy-1,3-dibromopropane, 1,3-diethoxy-1,3-dibromopropane, 1, 3-Dipropoxy-1,3-dibromopropane, 1,3-dibutoxy-1,3-dibromopropane, 1,4-dimethoxy-1,4-dibromobutane, 1,4-diethoxy-1,4-dibromobutane, 1,4-dipropoxy-1,4-dibromobutane, 1,4-dibutoxy-1,4-dibromobutane 1,2-diethoxy-1,2-diiodoethane, 1,2-dipropoxy-1,2-diiodoethane, 1,2-dimethoxy-1,2-diiodoethane, 1,2-dibutoxy-1,2-diiodoethane One or more of ethane, 1,3-dimethoxy-1,3-diiodopropane, 1,3-diethoxy-1,3-diiodopropane, 1,3-dipropoxy-1,3-diiodopropane, 1,3-dibutoxy-1,3-diiodopropane, 1,4-dimethoxy-1,4-diiodobutane, 1,4-diethoxy-1,4-diiodobutane, 1,4-dipropoxy-1,4-diiodobutane, 1,4-dibutoxy-1,4-diiodobutane and 1,2-diethoxy-1-chloro-2-bromo-ethane,

[0038] Optionally, the halogenated ether includes one or more of 1,2-diethoxy-1,2-dichloroethane, 1,2-dipropoxy-1,2-dichloroethane, 1,2-dimethoxy-1,2-dichloroethane, 1,2-diethoxy-1,2-dibromoethane, 1,2-dipropoxy-1,2-dibromoethane, 1,2-dibutoxy-1,2-dichloroethane, 1,3-diethoxy-1,3-dichloropropane and 1,2-diethoxy-1-chloro-2-bromo-ethane.

[0039] In some embodiments of the present application, the method satisfies at least one of the following conditions:

[0040] (1) The molar ratio of the halogenated ether to the fluorinating agent is 1:(2-10), and can be optionally 1:(2.5-5);

[0041] (2) The reaction time of the halogenated ether and the fluorinating agent is 2 h to 20 h, and can be optionally 4 h to 10 h.

[0042] The molar ratio of the halogenated ether to the fluorinating agent being within the above range is conducive to achieving a relatively complete replacement of the halogenated ether by the fluorinating agent, thereby increasing the yield of the fluoroether compound; and can also reduce the by-products generated due to excess reaction raw materials.

[0043] In some embodiments of the present application, after the reaction is completed, the method further comprises a post-treatment step:

[0044] The reaction solution is filtered and distilled to obtain the fluoroether compound.

[0045] The fluoroether compound can be purified by filtering and distilling the reaction solution, thereby improving the purity of the fluoroether compound.

[0046] The third aspect of the present application provides an electrolyte, comprising the fluoroether compound of the first aspect of the present application or the fluoroether compound prepared by the method of the second aspect of the present application.

[0047] A fourth aspect of the present application provides a secondary battery, comprising the electrolyte of the third aspect of the present application.

[0048] A fifth aspect of the present application provides an electrical device, comprising the secondary battery of the fourth aspect of the present application.

[0049] The electric device of the present application includes the secondary battery provided by the present application, and thus has at least the same advantages as the secondary battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is the NMR characterization spectrum of the fluoroether compound 1,2-diethoxy-1,2-difluoroethane prepared in Example 1.

[0051] Figure 2 is a schematic diagram of a secondary battery according to one embodiment of the present application.

[0052] Figure 3 yes Figure 2 An exploded view of a secondary battery according to an embodiment of the present application is shown.

[0053] Figure 4 is a schematic diagram of a secondary battery according to another embodiment of the present application.

[0054] Figure 5 is a schematic diagram of a secondary battery according to another embodiment of the present application.

[0055] Figure 6 yes Figure 5 An exploded view of a secondary battery according to an embodiment of the present application is shown.

[0056] Figure 7 FIG. 1 is a schematic diagram of an electric device using a secondary battery according to an embodiment of the present application as a power source.

[0057] Description of reference numerals:

[0058] 1 battery pack; 2 upper box; 3 lower box; 4 battery module; 5 battery cell; 51 shell; 52 electrode assembly; 53 top cover assembly. DETAILED DESCRIPTION

[0059] Hereinafter, the embodiments of the fluoroether compound and its preparation method, electrolyte, secondary battery and electric device of the present application are specifically disclosed in detail with appropriate reference to the drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0060] "Scope" disclosed in the present application is defined in the form of lower limit and upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope defined in this way includes or does not include end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following scope can be all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present 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 real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it 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.

[0061] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0062] 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.

[0063] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means 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), which means 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.

[0064] At present, in secondary batteries represented by lithium-ion batteries, the solvent in the electrolyte is usually carbonate organic solvents such as ethylene carbonate, propylene carbonate, and ethyl methyl carbonate. The oxidation stability of such organic solvents is not high, which makes the oxidation resistance of the electrolyte not high. Especially when the battery works at high voltage, the high voltage can easily oxidize the organic solvent, and the oxidized organic solvent is easy to react with the active material, affecting the battery cycle performance.

[0065] In order to solve the above technical problems, the present application proposes a fluoroether compound, which has high oxidation stability and is beneficial to improving the antioxidant capacity of the electrolyte and the cycle performance of the battery when used in the electrolyte of a secondary battery. The fluoroether compound will be described in detail below.

[0066] In the first aspect, the present application proposes a fluoroether compound, which includes the structural formula shown in formula (I):

[0067]

[0068] In formula (I), R 1 Each independently includes C 1～4 Alkanes, R 2 Includes single bonds or C 1～2 of alkanes.

[0069] In this application, unless otherwise specified, the term "alkane" refers to a saturated hydrocarbon containing primary (normal) carbon atoms, secondary carbon atoms, tertiary carbon atoms, or a combination thereof. Phrases containing this term, such as "C 1 ~C 4 "Alkyl" refers to an alkyl group containing 1 to 4 carbon atoms, each occurrence of which can be independently C 1 Alkyl, C 2 Alkyl, C 3 Alkyl or C4 Suitable examples include, but are not limited to, methyl (Me, -CH 3 ), ethyl (Et, -CH 2 CH 3 ), 1-propyl (n-Pr, n-propyl, -CH 2 CH 2 CH 3 ), 2-propyl (i-Pr, i-propyl, -CH (CH 3 ) 2 ), 1-butyl (n-Bu, n-butyl, -CH 2 CH 2 CH 2 CH 3 ), 2-methyl-1-propyl (i-Bu, i-butyl, -CH 2 CH(CH 3 ) 2 ), 2-butyl (s-Bu, s-butyl, -CH (CH 3 )CH 2 CH 3 ) and 2-methyl-2-propyl (t-Bu, t-butyl, -C(CH 3 ) 3 ).

[0070] The fluorinated ether compound of the structure shown in formula (I) provided in the present application contains two fluorine atoms in the molecule, which can effectively reduce the electron cloud density of the ether oxygen in the fluorinated ether compound molecule, increase the oxidation potential of the fluorinated ether compound, and thus improve its oxidation stability. At the same time, in the structural formula of formula (I), the fluorine atom is located in the middle of the molecular chain adjacent to the oxygen atom, which can further reduce the electron cloud density of the ether oxygen in the fluorinated ether compound molecule compared to the fluorine atom located at other positions, especially the fluorine atom located at the end of the molecular chain, thereby further increasing the oxidation potential of the fluorinated ether compound, thereby further improving its oxidation stability.

[0071] Specifically, in the structural formula shown in formula (I), since the group between the two ether oxygens in the molecule contains multiple fluorine atoms, the electron cloud density of the ether oxygen can be more effectively reduced compared to the introduction of fluorine atoms at the ends of both sides of the molecule. The introduction of fluorine atoms on the methylene carbon in the middle of the ether oxygen can simultaneously play an electron-withdrawing role on the two ether oxygens in the molecule, effectively reducing the electron-loss ability of the ether oxygen, thereby greatly reducing the HOMO (highest occupied molecular orbital) energy level of the fluorinated ether.

[0072] The analysis of the single molecule structure and its complex structure in the electrolyte based on first-principles calculations shows that when the same number of fluorine atoms are introduced between the ether oxygen of the molecule and at the ends of both sides of the molecule, the former has a much greater ability to resist electron loss than the latter, that is, the former has a much greater antioxidant capacity than the latter. Taking ethylene glycol diethyl ether (DEE) as an example, as shown in Table 2, the HOMO energy level of ethylene glycol diethyl ether itself is -6.999 eV. After introducing two fluorine atoms on the two methylene groups in the middle of DEE, 1,3-diethoxy-1,3-difluoropropane (HOMO energy level is -8.064 eV) is obtained. Compared with 1,2-bis(2-fluoroethoxy)ethane (HOMO energy level is -7.263 eV) obtained by introducing one fluorine atom at each end of DEE (a total of two fluorine atoms), the first-principles calculation results show that the HOMO energy level of 1,3-diethoxy-1,3-difluoropropane is nearly 0.9 eV lower than that of 1,2-bis(2-fluoroethoxy)ethane, and the HOMO energy level of 1,3-diethoxy-1,3-difluoropropane is nearly 1.1 eV lower than that of ethylene glycol diethyl ether. Based on this, it is shown that the introduction of fluorine atoms between the ether oxygen of the molecule can greatly improve the oxidation stability of the fluoroether compound, which can be manifested as a significant increase in its oxidation potential in the battery, thereby helping to improve the antioxidant capacity of the electrolyte and the cycle performance of the battery.

[0073] In some embodiments, the fluoroether compound includes one or more of 1,2-diethoxy-1,2-difluoroethane, 1,2-dipropoxy-1,2-difluoroethane, 1,2-dimethoxy-1,2-difluoroethane, 1,2-dibutoxy-1,2-difluoroethane, 1,3-dimethoxy-1,3-difluoropropane, 1,3-diethoxy-1,3-difluoropropane, 1,3-dipropoxy-1,3-difluoropropane, 1,3-dibutoxy-1,3-difluoropropane, 1,4-dimethoxy-1,4-difluorobutane, 1,4-diethoxy-1,4-difluorobutane, 1,4-dipropoxy-1,4-difluorobutane and 1,4-dibutoxy-1,4-difluorobutane.

[0074] Optionally, the fluoroether compound includes one or more of 1,2-diethoxy-1,2-difluoroethane, 1,2-dipropoxy-1,2-difluoroethane, 1,2-dimethoxy-1,2-difluoroethane and 1,2-dibutoxy-1,2-difluoroethane.

[0075] In a second aspect, the present application proposes a method for preparing a fluoroether compound, which is used to prepare the fluoroether compound described in the first aspect of the present application and may include the following steps:

[0076] S1, subjecting a fluorinating agent to a substitution reaction with a halogenated ether to prepare a fluoroether compound;

[0077] The fluoroether compound includes the structural formula shown in formula (I):

[0078]

[0079] In formula (I), R 1 Each independently includes C 1～4 Alkanes, R 2 Includes single bonds or C 1～2 of alkanes;

[0080] Wherein, the chemical formula of the fluorinating agent includes MF n , M includes at least one of Na, K, Cs, Sb and H, and n is an integer of 1 to 5;

[0081] The halogenated ether includes the structural formula shown in formula (II):

[0082]

[0083] In formula (II), R 1 Each independently includes C 1～4 Alkanes, R 2 Includes single bonds or C 1～2 Alkanes, X 1 and X 2 Each independently includes one of a chlorine atom, a bromine atom and an iodine atom.

[0084] The above method provided by the present application can directly replace the halogen atom in the halogenated ether with the fluorine atom by allowing the fluorinating agent to undergo a substitution reaction with the halogenated ether, thereby obtaining the fluoroether compound provided by the first aspect of the present application. The method does not involve other intermediate reaction processes, the process route is simple, and the yield and purity of the obtained fluoroether compound are high.

[0085] In some embodiments, the step of subjecting the fluorinating agent to a substitution reaction with a halogenated ether may further include the following steps:

[0086] S10, heat-treating the organic solution containing the fluorinating agent;

[0087] S20, at the temperature of the heat treatment, allowing the halogenated ether to contact and react with the fluorinating agent to prepare the fluoroether compound.

[0088] In the above steps S10 to S20, the organic solution containing the fluorinating agent is heat-treated and the halogenated ether is brought into contact with the fluorinating agent at the heat treatment temperature, thereby promoting the substitution reaction between the fluorinating agent and the halogenated ether bond and making the substitution reaction proceed more completely.

[0089] In some embodiments, the chemical formula of the fluorinating agent includes MF n, M includes at least one of Na, K, Cs, Sb and H, and n is an integer of 1 to 5.

[0090] In some embodiments, the fluorinating agent includes, but is not limited to, one or more of antimony trifluoride, antimony pentafluoride, anhydrous hydrofluoric acid, sodium fluoride, potassium fluoride, and cesium fluoride. It can be selected from one or more of antimony trifluoride, antimony pentafluoride, sodium fluoride, and potassium fluoride.

[0091] In some embodiments, the mass ratio of the fluorinating agent to the organic solvent is 1:(0.8-10). For example, the mass ratio of the fluorinating agent to the organic solvent can be 1:0.8, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10 or within the range of any of the above values.

[0092] In some embodiments, the organic solution further comprises an organic solvent, and the type of the organic solvent is not limited and can be selected according to actual needs.

[0093] In some embodiments, the organic solvent includes but is not limited to one or more of acetonitrile, dimethyl carbonate, diethyl carbonate, ethyl acetate, dichloromethane, chloroform, carbon tetrachloride and dimethyl sulfoxide, and can be selected from one or more of acetonitrile, ethyl acetate, dichloromethane and dimethyl sulfoxide.

[0094] The above-mentioned organic solvent can achieve relatively complete dissolution of the reaction raw materials, which is helpful to reduce the difficulty of the reaction between the reaction raw materials.

[0095] In some embodiments, the organic solution further comprises a phase transfer catalyst, and the type of the phase transfer catalyst is not limited and can be selected according to actual needs.

[0096] In some embodiments, the mass ratio of the phase transfer catalyst to the organic solvent is (0.003-0.02): 1. For example, the mass ratio of the phase transfer catalyst to the organic solvent can be 0.003: 1, 0.005: 1, 0.007: 1, 0.01: 1, 0.013: 1, 0.015: 1, 0.017: 1, 0.02: 1 or within the range of any of the above values.

[0097] In some embodiments, the phase transfer catalyst includes, but is not limited to, one or more of polyethers, crown ethers, quaternary ammonium salts, tertiary amines, and quaternary ammonium bases.

[0098] In some embodiments, the phase transfer catalyst includes, but is not limited to, one or more of 18-crown-6, 15-crown-5, cyclodextrin, chain polyethylene glycol, benzyltriethylammonium chloride, tetrabutylammonium bromide, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, pyridine and tributylamine. Optionally, the phase transfer catalyst includes 18-crown-6.

[0099] The fluorinating agent and halogenated ether provided as the reaction raw materials in the above method have poor compatibility. Adding the above phase transfer catalyst to the reaction raw materials can make the reaction raw materials mutually soluble and evenly mixed, which is beneficial to promote the reaction and improve the reaction efficiency.

[0100] In some embodiments, the temperature of the heat treatment is -20°C to 50°C. For example, the temperature of the heat treatment can be -20°C, -10°C, -5°C, 0°C, 5°C, 10°C, 20°C, 30°C, 40°C, 50°C or within the range of any of the above values. Optionally, the temperature of the heat treatment is -10°C to 10°C.

[0101] The preparation temperature of conventional fluoroether compounds is usually relatively high, which can easily cause the decomposition of the reaction raw materials; while the temperature of the heat treatment in the present application is within the above range, which is conducive to reducing the decomposition of the reaction raw materials and improving the stability of the reaction process. At the same time, the heat treatment temperature is within the above range, which is also conducive to increasing the reaction rate and reducing the generation of by-products; it is also conducive to reducing the polymerization reaction that may occur between the reaction raw materials and improving the performance and yield of the product fluoroether compound.

[0102] In some embodiments, the halogenated ether comprises the structural formula shown in formula (II):

[0103]

[0104] In formula (II), R 1 Each independently includes C 1～4 Alkanes, R 2 Includes single bonds or C 1～2 Alkanes, X 1 and X 2 Each independently includes one of a chlorine atom, a bromine atom and an iodine atom.

[0105] The halogenated ether selected in the present application contains a halogen atom between the ether oxygen, and the halogen atom can provide a substitution site for the substitution of the fluorine atom. The fluoroether compound of the present application is obtained by substitution with a fluorinating agent.

[0106] In some embodiments, the halogenated ether is, but is not limited to, 1,2-diethoxy-1,2-dichloroethane, 1,2-dipropoxy-1,2-dichloroethane, 1,2-dimethoxy-1,2-dichloroethane, 1,2-dibutoxy-1,2-dichloroethane, 1,3-dimethoxy-1,3-dichloropropane, 1,3-diethoxy-1,3-dichloropropane, 1,3-dipropoxy-1,3-dichloropropane, 1,3-dibutoxy-1,3-dichloropropane, 1,4-dimethoxy- 1,4-dichlorobutane, 1,4-diethoxy-1,4-dichlorobutane, 1,4-dipropoxy-1,4-dichlorobutane, 1,4-dibutoxy-1,4-dichlorobutane, 1,2-diethoxy-1,2-dibromoethane, 1,2-dipropoxy-1,2-dibromoethane, 1,2-dimethoxy-1,2-dibromoethane, 1,2-dibutoxy-1,2-dibromoethane, 1,3-dimethoxy-1,3-dibromopropane, 1,3-diethoxy-1,3-dibromopropane, 1, 3-Dipropoxy-1,3-dibromopropane, 1,3-dibutoxy-1,3-dibromopropane, 1,4-dimethoxy-1,4-dibromobutane, 1,4-diethoxy-1,4-dibromobutane, 1,4-dipropoxy-1,4-dibromobutane, 1,4-dibutoxy-1,4-dibromobutane 1,2-diethoxy-1,2-diiodoethane, 1,2-dipropoxy-1,2-diiodoethane, 1,2-dimethoxy-1,2-diiodoethane, 1,2-dibutoxy-1,2-diiodoethane One or more of ethane, 1,3-dimethoxy-1,3-diiodopropane, 1,3-diethoxy-1,3-diiodopropane, 1,3-dipropoxy-1,3-diiodopropane, 1,3-dibutoxy-1,3-diiodopropane, 1,4-dimethoxy-1,4-diiodobutane, 1,4-diethoxy-1,4-diiodobutane, 1,4-dipropoxy-1,4-diiodobutane, 1,4-dibutoxy-1,4-diiodobutane and 1,2-diethoxy-1-chloro-2-bromo-ethane.

[0107] Optionally, the halogenated ether includes one or more of 1,2-diethoxy-1,2-dichloroethane, 1,2-dipropoxy-1,2-dichloroethane, 1,2-dimethoxy-1,2-dichloroethane, 1,2-diethoxy-1,2-dibromoethane, 1,2-dipropoxy-1,2-dibromoethane, 1,2-dibutoxy-1,2-dichloroethane, 1,3-diethoxy-1,3-dichloropropane and 1,2-diethoxy-1-chloro-2-bromo-ethane.

[0108] As a non-limiting example, the halogenated ether (such as 1,2-diethoxy-1,2-dichloroethane) can be prepared by the following method: 60 grams (about 1 mole) of polymer glyoxal is dissolved in 92 grams (2 moles) of ethanol under heating, added to a 1L three-necked flask, cooled to 5°C, then diluted with 150 milliliters of carbon tetrachloride, and a total of 250 grams of thionyl chloride is added dropwise, and the ice bath temperature does not exceed 10°C. After adding about 40g of thionyl chloride, the mixture begins to cool by itself, replaces the ice bath with a water bath, and continues to drop thionyl chloride, and the reaction temperature is maintained at about 30°C with the help of a water bath. After the addition is completed, the reaction is stirred for another 2 hours. After the reaction is completed, the reaction solution is heated to 30°C. Carbon tetrachloride is recovered by distillation using a water pump, and 1,2-diethoxy-1,2-dichloroethane is obtained by further distillation to obtain 135g of product with a product purity of about 97%. It can be understood that other types of halogenated ethers can be prepared by replacing the preparation raw materials with corresponding dialdehydes or alcohols.

[0109] In some embodiments, the molar ratio of the halogenated ether to the fluorinating agent is 1:(2-10). For example, the molar ratio of the halogenated ether to the fluorinating agent can be 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10 or within the range of any of the above values. Optionally, the molar ratio of the halogenated ether to the fluorinating agent is 1:(2.5-5).

[0110] The molar ratio of the halogenated ether to the fluorinating agent being within the above range is conducive to achieving a relatively complete replacement of the halogenated ether by the fluorinating agent, thereby increasing the yield of the fluoroether compound; and can also reduce the by-products generated due to excess reaction raw materials.

[0111] In some embodiments, the reaction time of the halogenated ether and the fluorinating agent is 2 hours to 20 hours. For example, the reaction time of the halogenated ether and the fluorinating agent can be 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours or within the range of any of the above values. Optionally, the reaction time of the halogenated ether and the fluorinating agent is 4 hours to 10 hours.

[0112] The reaction time of the halogenated ether and the fluorinating agent being within the above range is beneficial to achieving a relatively complete substitution of the halogenated ether by the fluorinating agent and also beneficial to reducing the generation of by-products.

[0113] In some embodiments, after the reaction is completed, a post-treatment step S30 is further included:

[0114] S30, filtering and distilling the reaction solution to obtain the fluoroether compound.

[0115] The fluoroether compound can be purified by filtering and distilling the reaction solution, thereby improving the purity of the fluoroether compound.

[0116] In a third aspect, the present application provides an electrolyte comprising the fluoroether compound described in the first aspect of the present application or the fluoroether compound prepared by the method described in the second aspect of the present application.

[0117] It can be understood that the fluoroether compound can be used as a solvent in the electrolyte. It can be added to the electrolyte as a solvent alone or added to the electrolyte together with other conventional solvents.

[0118] Conventional fluoroether compounds have good reduction stability, but are not resistant to oxidation, that is, their oxidation stability is generally poor, resulting in poor antioxidant properties of the electrolyte. When the electrolyte is used at high voltage, conventional solvents and conventional fluoroether compounds are prone to decomposition. On the one hand, this leads to a reduction in the electrolyte, thereby deteriorating the wettability of the active material and affecting the battery capacity; on the other hand, the decomposed substances may have side reactions with the active material, affecting the battery's cycle performance. Therefore, conventional solvents and conventional fluoroether compounds are difficult to use in batteries with higher cut-off voltages.

[0119] The fluoroether compounds provided in the present application have lower HOMO energy levels, higher resistance to electron loss, higher oxidation resistance and oxidation stability. Therefore, when used in electrolytes, they can remain stable without being oxidized at higher battery voltages, and can be used in the field of high-voltage batteries. Compared with conventional solvents and conventional fluoroether compounds, the fluoroether compounds provided in the present application can improve the oxidation resistance of the electrolyte when used in electrolytes, especially when the electrolyte is used at high voltage, and thus can improve the capacity and cycle performance of the battery.

[0120] In a fourth aspect, the present application provides a secondary battery, which includes the electrolyte described in the third aspect of the present application.

[0121] The secondary battery, battery module, battery pack, and electric device of the present application are described below with reference to the accompanying drawings as appropriate.

[0122] In one embodiment of the present application, a secondary battery is provided. The secondary battery may include a lithium ion battery and a sodium ion battery.

[0123] Generally, a secondary battery includes a positive electrode sheet, a negative electrode sheet, an electrolyte and a separator. During the battery charging and discharging process, active ions are embedded and released back and forth between the positive electrode sheet and the negative electrode sheet. The electrolyte plays the role of conducting ions between the positive electrode sheet and the negative electrode sheet. The separator is set between the positive electrode sheet and the negative electrode sheet, mainly to prevent the positive and negative electrodes from short-circuiting, while allowing ions to pass through.

[0124] Positive electrode

[0125] 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, wherein the positive electrode film layer includes the positive electrode active material of the first aspect of the present application.

[0126] 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 any one or both of the two opposite surfaces of the positive electrode current collector.

[0127] 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.).

[0128] In some embodiments, the positive electrode active material may adopt a positive electrode active material for a battery known in the art. As an example, the positive electrode active material may include at least one of the following materials: a lithium-containing phosphate with an olivine structure, a lithium transition metal oxide, 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 oxides (such as LiCoO 2 ), lithium nickel oxide (such as LiNiO 2 ), lithium manganese oxide (such as LiMnO 2 、LiMn 2 O 4 ), 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 O 2 (Also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O 2 (Also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O 2 (Also referred to as NCM 211 )、LiNi 0.6 Co0.2 Mn 0.2 O 2 (Also referred to as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O 2 (Also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O 2 ) and its modified compounds, etc. Examples of lithium phosphates containing olivine structures may include, but are not limited to, lithium iron phosphate (such as LiFePO 4 (also referred to as LFP), composite materials of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), at least one of a composite material of lithium manganese phosphate and carbon, a composite material of lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.

[0129] The battery will be accompanied by Li deintercalation and consumption during the charge and discharge process, and the molar content of Li is different when the battery is discharged to different states. In the list of positive electrode materials in this application, the molar content of Li is the initial state of the material, that is, the state before feeding. The positive electrode material is used in the battery system, and the molar content of Li will change after charge and discharge cycles.

[0130] In the list of positive electrode materials in this application, the molar content of O is only a theoretical value. The release of oxygen from the lattice will cause the molar content of oxygen to change, and the actual molar content of O will fluctuate.

[0131] In some embodiments, the positive electrode active material may also include at least one of the following materials: sodium transition metal oxide, polyanionic compound and Prussian blue compound. 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.

[0132] As an optional technical solution of the present application, in the sodium transition metal oxide, the transition metal includes at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr and Ce. The sodium transition metal oxide is, for example, Na x MO 2 , wherein M includes one or more of Ti, V, Mn, Co, Ni, Fe, Cr and Cu, and 0<x≤1.

[0133] As an optional technical solution of the present application, the polyanionic compound can be a compound having sodium ions, transition metal ions and tetrahedral (YO4 ) n- A class of compounds with anionic units. The transition metal includes at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr and Ce; Y includes at least one of P, S and Si; n represents (YO 4 ) n- valence state.

[0134] Polyanionic compounds can also be sodium ions, transition metal ions, tetrahedral (YO 4 ) n- A class of compounds containing anion units and halogen anions. The transition metal includes at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr and Ce; Y includes at least one of P, S and Si, and n represents (YO 4 ) n- valence state; the halogen includes at least one of F, Cl and Br.

[0135] The polyanionic compound can also be a compound having sodium ions, tetrahedral (YO 4 ) n- Anion unit, polyhedral unit (ZO y ) m+ and an optional halogen anion. Y includes at least one of P, S and Si, and n represents (YO 4 ) n- valence state; Z represents a transition metal, including at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr and Ce; m represents (ZO y ) m+ valence state; the halogen includes at least one of F, Cl and Br.

[0136] Polyanionic compounds are, for example, NaFePO 4 、Na 3 V 2 (PO4) 3 (Sodium vanadium phosphate, referred to as NVP), Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ), NaM'PO4F (M' includes one or more of V, Fe, Mn and Ni) and Na 3 (VO y ) 2 (PO 4 ) 2 F 3-2y At least one of (0≤y≤1).

[0137] Prussian blue compounds can be sodium ions, transition metal ions and cyanide ions (CN - ). The transition metal includes at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr and Ce. Prussian blue compounds are, for example, Na a Me b Me' c (CN) 6 , wherein Me and Me' each independently include at least one of Ni, Cu, Fe, Mn, Co and Zn, 0<a≤2, 0<b<1, 0<c<1.

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

[0139] In some embodiments, the positive electrode film layer may further include 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 in the following manner: 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 collector, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained.

[0141] The positive electrode sheet of the present application does not exclude other additional functional layers in addition to the positive electrode film layer. For example, in some embodiments, the positive electrode sheet of the present application also includes a conductive primer layer (for example, composed of a conductive agent and a binder) sandwiched between the positive electrode collector and the positive electrode film layer and disposed on the surface of the positive electrode collector. In other embodiments, the positive electrode sheet of the present application also includes a protective layer covering the surface of the positive electrode film layer.

[0142] Negative electrode

[0143] The negative electrode sheet includes a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector, wherein the negative electrode film layer includes a negative electrode active material.

[0144] As an example, the negative electrode current collector has two surfaces opposite to each other in its 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.

[0145] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, a copper foil may be used. The composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material substrate. 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 material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0146] In some embodiments, the negative electrode active material may adopt the negative electrode active material for the battery 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 oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, 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.

[0147] In some embodiments, the negative electrode film layer may further include 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).

[0148] In some embodiments, the negative electrode film layer may further include a conductive agent. The conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers. In some embodiments, the negative electrode film layer may further include other additives, such as a thickener (such as sodium carboxymethyl cellulose (CMC-Na)).

[0149] In some embodiments, the negative electrode sheet can be prepared in the following manner: 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 collector, and after drying, cold pressing and other processes, the negative electrode sheet can be obtained.

[0150] The negative electrode plate of the present application does not exclude other additional functional layers in addition to the negative electrode film layer. For example, in some embodiments, the negative electrode plate of the present application also includes a conductive primer layer (for example, composed of a conductive agent and a binder) sandwiched between the negative electrode current collector and the negative electrode film layer and disposed on the surface of the negative electrode current collector. In some other embodiments, the negative electrode plate of the present application also includes a protective layer covering the surface of the negative electrode film layer.

[0151] Electrolytes

[0152] The electrolyte plays the role of conducting ions between the positive electrode and the negative electrode. The present application has no specific restrictions on the type of electrolyte, which can be selected according to needs. For example, the electrolyte can be liquid, gel or all-solid.

[0153] In some embodiments, the electrolyte is an electrolyte solution, which includes an electrolyte salt and a solvent.

[0154] In some embodiments, the electrolyte salt may be a lithium salt. As an example, the lithium 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 difluorobis(oxalatophosphate), and lithium tetrafluorooxalatophosphate.

[0155] In some embodiments, the electrolyte salt may also be a sodium salt. As an example, the sodium salt includes but is not limited to NaPF 6 、NaClO 4 、NaBCl 4 、NaSO 3 CF 3 and Na(CH 3 )C 6 H 4 SO 3 The above sodium salts can be used alone or in combination of two or more.

[0156] In some embodiments, the solvent may be the fluoroether compound provided in the present application, or the fluoroether compound provided in the present application may be used in combination with one or more conventional solvents.

[0157] It is understood that when the fluoroether compound is used in combination with a conventional solvent, the volume ratio of the fluoroether compound to the conventional solvent is not limited and any ratio can be used.

[0158] In some embodiments, the conventional solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl 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 sulfone, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.

[0159] In some embodiments, the electrolyte may further include additives, such as 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, additives that improve battery high or low temperature performance, etc.

[0160] Isolation film

[0161] 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 stability and mechanical stability can be selected.

[0162] In some embodiments, the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The isolation membrane includes a single-layer film and a multi-layer composite film, without particular limitation. When the isolation membrane is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation.

[0163] 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.

[0164] In some embodiments, the secondary battery may include an outer package, which may be used to encapsulate the electrode assembly and the electrolyte.

[0165] In some embodiments, the outer packaging of the secondary battery includes a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc. The outer packaging of the secondary battery also includes a soft package, such as a bag-type soft package. The material of the soft package includes plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, and polybutylene succinate. The present application has no particular restrictions on the shape of the secondary battery, which includes cylindrical, square, or other arbitrary shapes. For example, Figure 2 The battery cell 5 is a square structure as an example.

[0166] In some embodiments, reference Figure 3, the outer packaging may include a shell 51 and a cover plate 53. Among them, 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 battery cell 5 can be one or more, and those skilled in the art can select according to specific actual needs.

[0167] In some embodiments, the secondary battery also includes a battery module assembled from a plurality of battery cells. The battery module may include a plurality of battery cells, and the specific number can be adjusted by those skilled in the art according to the application and capacity of the battery module.

[0168] Figure 4 4 is an example of a battery module. Figure 4 In the battery module 4, a plurality of battery cells 5 are arranged in sequence along the length direction of the battery module 4. Of course, they can also be arranged in any other manner. Further, the plurality of battery cells 5 can be fixed by fasteners.

[0169] Optionally, the battery module 4 may further include a housing having a receiving space, and the plurality of battery cells 5 are received in the receiving space.

[0170] 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 according to the application and capacity of the battery pack.

[0171] In some embodiments, the battery cells mentioned above may also be directly assembled into a battery pack, and the number of battery cells contained in the battery pack may be adjusted according to the application and capacity of the battery pack.

[0172] Figure 5 and Figure 6 1 is a battery pack 1 as an example. Figure 5 and Figure 6 The battery pack 1 may include a battery box and a plurality of 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 a closed space for accommodating the battery modules 4. The plurality of battery modules 4 can be arranged in the battery box in any manner.

[0173] In addition, the present application also provides an electric device, which includes a secondary battery provided in the present application. The secondary battery can be used as a power source for the electric device, or 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 are not limited thereto.

[0174] As the electrical device, a secondary battery can be selected according to its usage requirements.

[0175] Figure 7 The power consumption device is taken as an example. The power consumption device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. In order to meet the high power and high energy density requirements of the power consumption device for the secondary battery, a battery pack or a battery module can be used.

[0176] Another example of a device includes a mobile phone, a tablet computer, a notebook computer, etc. Such a device is usually required to be thin and light, and a secondary battery may be used as a power source.

[0177] Example

[0178] Hereinafter, the embodiments of the present application will be described. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If no specific techniques or conditions are indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0179] Example 1

[0180] Put 544g (2.5mol) of antimony pentafluoride and 800mL (629g) of solvent acetonitrile into a 2000mL three-necked flask, add 5g of catalyst 18-crown ether-6, stir and mix evenly to obtain a mixed solution. At -10°C, add 186g of 1,2-diethoxy-1,2-dichloroethane and 100mL of acetonitrile mixed solution to the mixed solution at a uniform rate, the addition time is about 2h to 3h, and the stirring reaction is continued for 2h to 3h after the addition is completed to obtain a crude product. Filter the crude product to remove solid impurities, rotary evaporate the solvent and perform distillation to obtain a pure product containing the fluoroether compound 1,2-diethoxy-1,2-difluoroethane, and the pure product needs to be stored at low temperature with nitrogen filling.

[0181] Embodiments 2 to 28

[0182] The preparation method of the fluoroether compound is similar to that of Example 1, except that the relevant parameters in the preparation process are adjusted. The specific parameters are shown in Table 1 below.

[0183] Table 1

[0184]

[0185] Table 2

[0186]

[0187]

[0188] Test Section

[0189] (1) MRI test

[0190] The fluoroether compound synthesized in Example 1 was tested using a nuclear magnetic resonance spectrometer (equipment model: AVANCE III 500 MHz NMR).

[0191] It can be seen from Table 1 above that the fluoroether compound prepared by the method provided in the present application has a higher purity; it can be seen from Table 2 above that the fluoroether compound prepared in the present application has a relatively lower HOMO energy level, indicating that it has a higher oxidation stability, which is beneficial to improving the antioxidant capacity of the electrolyte and the cycle stability of the battery.

[0192] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A fluoroether compound, characterized in that Including the structural formula shown in formula (I): In formula (I), R1 each independently comprises C 1～4 Alkanes, R2 includes a single bond or C 1～2 of alkanes.

2. The fluoroether compound according to claim 1, characterized in that The fluoroether compound includes one or more of 1,2-diethoxy-1,2-difluoroethane, 1,2-dipropoxy-1,2-difluoroethane, 1,2-dimethoxy-1,2-difluoroethane, 1,2-dibutoxy-1,2-difluoroethane, 1,3-dimethoxy-1,3-difluoropropane, 1,3-diethoxy-1,3-difluoropropane, 1,3-dipropoxy-1,3-difluoropropane, 1,3-dibutoxy-1,3-difluoropropane, 1,4-dimethoxy-1,4-difluorobutane, 1,4-diethoxy-1,4-difluorobutane, 1,4-dipropoxy-1,4-difluorobutane and 1,4-dibutoxy-1,4-difluorobutane; Optionally, the fluoroether compound includes one or more of 1,2-diethoxy-1,2-difluoroethane, 1,2-dipropoxy-1,2-difluoroethane, 1,2-dimethoxy-1,2-difluoroethane and 1,2-dibutoxy-1,2-difluoroethane.

3. A method for preparing a fluoroether compound, characterized in that: include: The fluorinating agent is subjected to a substitution reaction with a halogenated ether to prepare a fluoroether compound; The fluoroether compound includes the structural formula shown in formula (I): In formula (I), R1 each independently comprises C 1～4 Alkanes, R2 includes a single bond or C 1～2 of alkanes; Wherein, the chemical formula of the fluorinating agent includes MF n , M includes at least one of Na, K, Cs, Sb and H, and n is an integer of 1 to 5; The halogenated ether includes the structural formula shown in formula (II): In formula (II), R1 each independently comprises C 1～4 Alkanes, R2 includes a single bond or C 1～2 An alkane, X1 and X2 each independently include one of a chlorine atom, a bromine atom and an iodine atom.

4. The method according to claim 3, characterized in that The step of subjecting the fluorinating agent to a substitution reaction with the halogenated ether comprises: heat-treating an organic solution containing the fluorinating agent; At the heat treatment temperature, the halogenated ether is contacted with the fluorinating agent and reacted to prepare the fluoroether compound; Optionally, the organic solution comprises an organic solvent; Optionally, the organic solvent includes one or more of acetonitrile, dimethyl carbonate, diethyl carbonate, ethyl acetate, dichloromethane, chloroform, carbon tetrachloride and dimethyl sulfoxide, and may be one or more of acetonitrile, ethyl acetate, dichloromethane and dimethyl sulfoxide.

5. The method according to claim 3 or 4, characterized in that: The fluorinating agent includes one or more of antimony trifluoride, antimony pentafluoride, anhydrous hydrofluoric acid, sodium fluoride, potassium fluoride and cesium fluoride, and can be selected from one or more of antimony trifluoride, antimony pentafluoride, sodium fluoride and potassium fluoride.

6. The method according to claim 4, characterized in that The organic solution satisfies at least one of the following conditions: (1) The mass ratio of the fluorinating agent to the organic solvent is 1:(0.8-10); (2) the organic solution further comprises a phase transfer catalyst; Optionally, the mass ratio of the phase transfer catalyst to the organic solvent is (0.003-0.02):1; Optionally, the phase transfer catalyst includes one or more of polyether, crown ether, quaternary ammonium salt, tertiary amine and quaternary ammonium base; Optionally, the phase transfer catalyst includes one or more of 18-crown-6, 15-crown-5, cyclodextrin, chain polyethylene glycol, benzyltriethylammonium chloride, tetrabutylammonium bromide, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, pyridine and tributylamine; Further optionally, the phase transfer catalyst includes 18-crown-6.

7. The method according to claim 3 or 4, characterized in that: The temperature of the heat treatment is -20°C to 50°C, and can be optionally -10°C to 10°C.

8. The method according to claim 3 or 4, characterized in that: The halogenated ethers include 1,2-diethoxy-1,2-dichloroethane, 1,2-dipropoxy-1,2-dichloroethane, 1,2-dimethoxy-1,2-dichloroethane, 1,2-dibutoxy-1,2-dichloroethane, 1,3-dimethoxy-1,3-dichloropropane, 1,3-diethoxy-1,3-dichloropropane, 1,3-dipropoxy-1,3-dichloropropane, 1,3-dibutoxy-1,3-dichloropropane, 1,4-dimethoxy-1,4-dichlorobutane, 1 ,4-diethoxy-1,4-dichlorobutane, 1,4-dipropoxy-1,4-dichlorobutane, 1,4-dibutoxy-1,4-dichlorobutane, 1,2-diethoxy-1,2-dibromoethane, 1,2-dipropoxy-1,2-dibromoethane, 1,2-dimethoxy-1,2-dibromoethane, 1,2-dibutoxy-1,2-dibromoethane, 1,3-dimethoxy-1,3-dibromopropane, 1,3-diethoxy-1,3-dibromopropane, 1,3-dipropoxy- 1,3-dibromopropane, 1,3-dibutoxy-1,3-dibromopropane, 1,4-dimethoxy-1,4-dibromobutane, 1,4-diethoxy-1,4-dibromobutane, 1,4-dipropoxy-1,4-dibromobutane, 1,4-dibutoxy-1,4-dibromobutane 1,2-diethoxy-1,2-diiodoethane, 1,2-dipropoxy-1,2-diiodoethane, 1,2-dimethoxy-1,2-diiodoethane, 1,2-dibutoxy-1,2-diiodoethane, One or more of 1,3-dimethoxy-1,3-diiodopropane, 1,3-diethoxy-1,3-diiodopropane, 1,3-dipropoxy-1,3-diiodopropane, 1,3-dibutoxy-1,3-diiodopropane, 1,4-dimethoxy-1,4-diiodobutane, 1,4-diethoxy-1,4-diiodobutane, 1,4-dipropoxy-1,4-diiodobutane, 1,4-dibutoxy-1,4-diiodobutane and 1,2-diethoxy-1-chloro-2-bromo-ethane, Optionally, the halogenated ether includes one or more of 1,2-diethoxy-1,2-dichloroethane, 1,2-dipropoxy-1,2-dichloroethane, 1,2-dimethoxy-1,2-dichloroethane, 1,2-diethoxy-1,2-dibromoethane, 1,2-dipropoxy-1,2-dibromoethane, 1,2-dibutoxy-1,2-dichloroethane, 1,3-diethoxy-1,3-dichloropropane and 1,2-diethoxy-1-chloro-2-bromo-ethane.

9. The method according to claim 3 or 4, characterized in that: Satisfy at least one of the following conditions: (1) The molar ratio of the halogenated ether to the fluorinating agent is 1:(2-10), and can be optionally 1:(2.5-5); (2) The reaction time of the halogenated ether and the fluorinating agent is 2 h to 20 h, and can be optionally 4 h to 10 h.

10. The method according to claim 3 or 4, characterized in that: After the reaction is completed, the following post-processing steps are also included: The reaction solution is filtered and distilled to obtain the fluoroether compound.

11. An electrolyte, characterized in that: The invention comprises the fluoroether compound according to claim 1 or 2 or the fluoroether compound prepared by the method according to any one of claims 3 to 10.

12. A secondary battery, characterized in that: Comprising the electrolyte according to claim 11.

13. An electrical device, characterized in that: Includes the secondary battery as claimed in claim 12.

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