Electrolyte solute, preparation method and application thereof

Abstract

This application discloses an electrolyte solute, its preparation method, and its application. The electrolyte solute comprises an olefinic cyclohexene carboxylic acid compound obtained by the reaction of conjugated diene carboxylic acids. The conjugated diene carboxylic acid includes at least one compound having the structure shown in Formula III: wherein X and Y are each independently selected from H, -RO-COOH, substituted or unsubstituted C1-10 saturated hydrocarbon groups, etc., and at least one of X and Y is -RO-COOH; RO represents a directly bonded or C1-10 saturated hydrocarbon group. The electrolyte solute of this application, comprising an olefinic cyclohexene carboxylic acid compound with unsaturated hydrocarbon functional groups, can both improve the flash voltage of the electrolyte and maintain low viscosity and high conductivity.

Description

Technical Field

[0001] This application relates to the field of capacitor technology, and in particular to an electrolyte solute, its preparation method, and its application. Background Technology

[0002] Electrolytic capacitors are indispensable basic components in various electronic products. The electrolyte, as the cathode of the electrolytic capacitor, plays a crucial role. It provides oxygen ions and repairs the anolyte film, thus determining the capacitor's operating temperature range, rated voltage, loss factor, impedance, rated ripple current, and service life. Therefore, the electrolyte directly affects the performance of the electrolytic capacitor.

[0003] The development of electrolytes for electrolytic capacitors has mainly gone through three stages: borate glycol system, straight-chain carboxylate glycol system, and branched-chain carboxylate glycol system.

[0004] The esterification of boric acid and ethylene glycol, as well as the conversion of boric acid into metaboric acid, both produce water. This water reacts with aluminum foil to generate hydrogen gas, causing the capacitor to bulge and fail. Because it cannot be used at high temperatures, it has been largely phased out.

[0005] The more carbon atoms in a straight-chain carboxylate, the higher the flash voltage. However, its solubility decreases with increasing molecular weight. For example, the solubility of commonly used ammonium sebacate in ethylene glycol is less than 5%, which leads to increased impedance. Furthermore, it is prone to crystallization at low temperatures, thus limiting the operating temperature range of the capacitor.

[0006] Branched polycarboxylate salts, as electrolyte solutes, exhibit relatively high solubility in multi-component solvents, are not prone to crystallization at low temperatures, have a wide operating temperature range, and produce electrolytes with high conductivity, resulting in capacitors with strong voltage withstand and high ripple current resistance. However, it is difficult for branched polycarboxylate electrolytes to reach voltages above 500V. Currently, improving the flashover voltage of electrolytes requires the addition of polyvinyl alcohol or polyacrylic acid flashover enhancers, which can achieve a flashover voltage of 700V. Although this increases the flashover voltage, the electrolyte with polymeric flashover enhancers has higher viscosity and lower conductivity, limiting its application range.

[0007] Currently, related research includes, for example, patent CN 109192513B, which reports a method for preparing a mixture of branched polycarboxylic acid ammonium salts. The method involves reacting cyclohexanone and hydrogen peroxide in an alcohol solvent, then adding potassium sorbate or methyl sorbate to produce a mixture of branched polycarboxylic acid esters. This mixture is then subjected to saponification, acidification, and ammoniation to obtain branched polycarboxylic acid ammonium salts with a carbon chain length of ten or more carbon atoms. Patent CN 117894594A reports a method involving the catalytic oxidation of cyclohexanone acid, followed by reaction with methyl undecenoate in the presence of a reducing agent to obtain a mixture of branched polycarboxylic acid esters, which is then hydrolyzed to form branched polycarboxylic acids, and ammonified to obtain ammonium salts. However, these studies involve numerous reaction steps, and hydrogen peroxide poses certain hazards during production, requiring controlled low temperatures during the reaction.

[0008] Therefore, there is an urgent need to develop an electrolyte solute that has advantages such as low viscosity, high conductivity, and high voltage resistance, while also having a simple preparation process, good safety, and ease of operation. Summary of the Invention

[0009] In view of this, one object of this application is to provide an electrolyte solute containing an olefinic cyclohexene carboxylic acid compound obtained by the reaction of conjugated diene carboxylic acid, the olefinic cyclohexene carboxylic acid compound containing multiple unsaturated hydrocarbon groups, which can improve the flash voltage of the electrolyte while taking into account the low viscosity and high conductivity characteristics of small molecule carboxylic acids.

[0010] Another objective of this application is to provide a method for preparing an electrolyte solute.

[0011] Another objective of this application relates to the use of electrolyte solutes.

[0012] To achieve the above objectives, the first aspect of this application provides an electrolyte solute comprising an olefinic cyclohexene carboxylic acid compound, said olefinic cyclohexene carboxylic acid compound being obtained by the reaction of conjugated diene carboxylic acid.

[0013] In some embodiments, the conjugated dienic acid comprises at least one of compounds having the structure shown in Formula III:

[0014]

[0015] X and Y are each independently selected from one of H, -R0-COOH, C1-10 saturated hydrocarbon group, substituted C1-10 saturated hydrocarbon group, C2-10 unsaturated hydrocarbon group, or substituted C2-10 unsaturated hydrocarbon group, and at least one of X and Y is -R0-COOH, where R0 represents a directly bonded or C1-10 saturated hydrocarbon group.

[0016] In some embodiments, in compounds having the structure shown in Formula III, the substituents in the substituted C1-10 saturated hydrocarbon groups and the substituted C2-10 unsaturated hydrocarbon groups are selected from at least one of ether, sulfone, sulfoxide, cyano, ester, hydroxyl, carbonyl, carboxyl, and amide groups.

[0017] In some embodiments, the conjugated dienic acid includes at least one of 2,4-pentadienoic acid, sorbic acid, 2,4-hexadienoic acid, 5-phenyl-2,4-pentadienoic acid, and conjugated linoleic acid.

[0018] In some embodiments, the olefinic cyclohexene carboxylic acid compound includes at least one of the compounds shown in Formula I and Formula II.

[0019]

[0020] R1 and R1' are each independently selected from one of hydrogen, a C1-10 saturated hydrocarbon group, a substituted C1-10 saturated hydrocarbon group, a C2-10 unsaturated hydrocarbon group, and a substituted C2-10 unsaturated hydrocarbon group; R2, R2', R3, and R3' are each independently selected from one of hydrogen, a C1-10 saturated hydrocarbon group, and a C2-10 unsaturated hydrocarbon group, and at least one of R2 and R3 contains a C2-10 unsaturated hydrocarbon group, and at least one of R2' and R3' contains a C2-10 unsaturated hydrocarbon group.

[0021] In some embodiments, at least one of R2 and R3 contains an unsaturated hydrocarbon group with a C=C bond of C2-10.

[0022] Preferably, R3 contains C2-10 unsaturated hydrocarbon groups with C=C bonds.

[0023] In some embodiments, at least one of R2' and R3' contains an unsaturated hydrocarbon group with a C=C bond of C2-10.

[0024] Preferably, R3' contains C2-10 unsaturated hydrocarbon groups with C=C bonds.

[0025] In some embodiments, in the compounds shown in Formula I and / or Formula II, the substituents in the substituted C1-10 saturated hydrocarbon groups and the substituted C2-10 unsaturated hydrocarbon groups are selected from at least one of ether, sulfone, sulfoxide, cyano, ester, hydroxyl, carbonyl, carboxyl, and amide groups.

[0026] In some embodiments, R1 and R1' are each independently selected from one of the following: hydrogen, a C1-10 straight-chain saturated hydrocarbon group, a C1-10 branched saturated hydrocarbon group, a substituted C1-10 straight-chain saturated hydrocarbon group, a substituted C1-10 branched saturated hydrocarbon group, a C2-10 straight-chain unsaturated hydrocarbon group, a C2-10 branched unsaturated hydrocarbon group, a substituted C2-10 straight-chain unsaturated hydrocarbon group, a substituted C2-10 branched unsaturated hydrocarbon group, a C3-10 saturated cyclic hydrocarbon group, a C3-10 unsaturated cyclic hydrocarbon group, a substituted C3-10 saturated cyclic hydrocarbon group, and a substituted C3-10 unsaturated cyclic hydrocarbon group.

[0027] Preferably, R1 and R1' are each independently selected from hydrogen, a C1-10 straight-chain saturated hydrocarbon group, a substituted C1-10 straight-chain saturated hydrocarbon group, a C2-10 straight-chain unsaturated hydrocarbon group, a substituted C2-10 straight-chain unsaturated hydrocarbon group, a three-membered ring saturated hydrocarbon group, a three-membered ring unsaturated hydrocarbon group, a four-membered ring saturated hydrocarbon group, a four-membered ring unsaturated hydrocarbon group, a five-membered ring saturated hydrocarbon group, a five-membered ring unsaturated hydrocarbon group, a six-membered ring saturated hydrocarbon group, a six-membered ring unsaturated hydrocarbon group, and phenyl.

[0028] In some embodiments, R2, R2', R3, and R3' are each independently selected from one of hydrogen, a C1-10 straight-chain saturated hydrocarbon group, a C2-10 straight-chain unsaturated hydrocarbon group, a C3-10 saturated cyclic hydrocarbon group, and a C3-10 unsaturated cyclic hydrocarbon group.

[0029] Preferably, R2, R2', R3, and R3' are each independently selected from one of the following: hydrogen, C1-10 straight-chain saturated hydrocarbon groups, C2-10 straight-chain unsaturated hydrocarbon groups, three-membered ring saturated hydrocarbon groups, three-membered ring unsaturated hydrocarbon groups, four-membered ring saturated hydrocarbon groups, four-membered ring unsaturated hydrocarbon groups, five-membered ring saturated hydrocarbon groups, five-membered ring unsaturated hydrocarbon groups, six-membered ring saturated hydrocarbon groups, six-membered ring unsaturated hydrocarbon groups, and phenyl.

[0030] In some embodiments, R1 and R1' are each independently selected from one of hydrogen, a substituted C1-10 saturated hydrocarbon group, and a substituted C2-10 unsaturated hydrocarbon group, and R3 and R3' are each independently selected from one of hydrogen, a C2-10 saturated hydrocarbon group, and a C2-10 unsaturated hydrocarbon group.

[0031] In some embodiments, the compound represented by Formula I is selected from at least one of compounds P1-P8:

[0032]

[0033] In some embodiments, the compound represented by Formula II is selected from at least one of compounds T1-T8:

[0034]

[0035]

[0036] The second aspect of this application discloses a method for preparing an electrolyte solute, comprising:

[0037] The crude product is obtained by heating conjugated dienic acid or by mixing conjugated dienic acid with a polymerization inhibitor and then heating it.

[0038] The crude product was purified to obtain the olefinic cyclohexene carboxylic acid compound.

[0039] In some embodiments, the reaction temperature of the heating reaction is 80-250°C.

[0040] In some embodiments, the reaction time of the heating reaction is 3-50 hours.

[0041] In some embodiments, the conjugated dienic acid and the polymerization inhibitor are mixed in a molar ratio of 10:(0.001-1).

[0042] In some embodiments, the polymerization inhibitor includes at least one of piperidinol oxide, 2-tert-butylhydroquinone, and hydroquinone.

[0043] The third aspect of this application relates to the application of the electrolyte solute described in this application or the electrolyte solute prepared by the preparation method described in this application in an electrolyte.

[0044] In some embodiments, the electrolyte includes the electrolyte solute described in this application or the electrolyte solute prepared by the method described in this application, organic solvents, waterproofing agents, hydrogen scavenging agents, flash voltage boosters, etc.

[0045] In some embodiments, the mass content of the electrolyte solute in the electrolyte is 1-20%.

[0046] In some embodiments, the organic solvent includes, but is not limited to, at least one of alcohol solvents, alcohol ether solvents, γ-butyrolactone, butyl acetate, etc.

[0047] In some embodiments, the electrolyte further includes a pH adjuster for adjusting the pH of the electrolyte to 5-8.

[0048] The electrolyte solute described in this application can bring at least the following beneficial effects:

[0049] The electrolyte contains an olefinic cyclohexene carboxylic acid compound obtained by the reaction of conjugated diene carboxylic acids. This olefinic cyclohexene carboxylic acid compound contains multiple unsaturated hydrocarbon groups and carboxyl groups, and has a branched chain characteristic. This gives it good solubility in organic solvents in the electrolyte, low viscosity for easy wetting, and high flash voltage. Consequently, the electrolyte containing this olefinic cyclohexene carboxylic acid compound has the advantages of low viscosity, high conductivity, and excellent withstand voltage performance. After long-term high-temperature testing, the conductivity changes little, and the high-temperature stability is good, which can meet the requirements of low, medium, and high voltage aluminum electrolytic capacitors. In addition, the compounds shown in Formula I and Formula II have good low-temperature solubility. The electrolyte solution is clear and free of turbidity at -20°C, exhibiting good low-temperature stability and expanding its application range.

[0050] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0051] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings.

[0052] in, Figure 1 The mass spectrum of the electrolyte solute prepared in Example 1, wherein the molecular formula of the substance with a mass-to-charge ratio of 223.0993 is C 12 H 16 O4-H represents two repeating units of sorbic acid C6H8O2, and -H is introduced by the negative ion testing mode. Detailed Implementation

[0053] The embodiments of this application are described in detail below. These embodiments are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0054] In this application, the disclosure of numerical ranges includes all values ​​throughout the range and the disclosure of further subdivisions of the range, including the endpoints and subranges given for these ranges.

[0055] Unless otherwise specified, all raw materials and equipment involved in this application are self-made through commercial means or known methods; and all methods involved are conventional methods unless otherwise specified.

[0056] In this application, unless otherwise stated, the term "saturated" means a compound or linker that does not contain any carbon-carbon double or triple bonds.

[0057] In this application, unless otherwise stated, the term "unsaturated" refers to a compound or linker containing carbon-carbon double or triple bonds, particularly carbon-carbon double bonds.

[0058] In this application, unless otherwise stated, "hydrocarbon group" refers to a group containing only carbon and hydrogen atoms, generally referring to the group remaining after the corresponding hydrocarbon loses a hydrogen atom (H).

[0059] In this application, unless otherwise stated, the term "substituted" means that the hydrogen in the structure is replaced by a substituent. A "substituent" is an atom or group that replaces a hydrogen atom when a hydrocarbon is "substituted".

[0060] In this application, unless otherwise stated, the term "ether group" means "-O-".

[0061] In this application, unless otherwise stated, the term "sulfone" means "-SO2-".

[0062] In this application, unless otherwise stated, the term "sulfonyl" refers to "-S(=O)-".

[0063] In this application, unless otherwise stated, the term "cyano" refers to a group in which carbon and nitrogen atoms are connected by a triple bond, with the chemical formula -CN.

[0064] In this application, unless otherwise stated, the term "ester group" refers to the functional group of an ester in a carboxylic acid derivative, with the structural formula -COOR (R is generally an alkyl group or other non-H group).

[0065] In this application, unless otherwise stated, the term "hydroxyl" means "-OH".

[0066] In this application, unless otherwise stated, the term "carbonyl" means "C=O".

[0067] In this application, unless otherwise stated, the term "amide group" refers to a group in which the hydroxyl group of a carboxylic acid is replaced by an amino (or amine) group and one hydrogen atom is formally eliminated, such as -NHC(O)CH3.

[0068] The prefix "Cu-v" indicates that the following group has from u to v carbon atoms. For example, "C1-10 chain hydrocarbon group" means that the chain hydrocarbon group has 1 to 10 carbon atoms.

[0069] <Electrolyte solute>

[0070] The electrolyte solute in the embodiments of this application includes an olefinic cyclohexene carboxylic acid compound, which is obtained by the reaction of conjugated diene carboxylic acid.

[0071] In some embodiments, the olefinic cyclohexene carboxylic acid compound includes at least one of the compounds shown in Formula I and Formula II.

[0072]

[0073] R1 and R1' are each independently selected from one of hydrogen, a C1-10 saturated hydrocarbon group, a substituted C1-10 saturated hydrocarbon group, a C2-10 unsaturated hydrocarbon group, and a substituted C2-10 unsaturated hydrocarbon group; R2, R2', R3, and R3' are each independently selected from one of hydrogen, a C1-10 saturated hydrocarbon group, and a C2-10 unsaturated hydrocarbon group, and at least one of R2 and R3 contains a C2-10 unsaturated hydrocarbon group, and at least one of R2' and R3' contains a C2-10 unsaturated hydrocarbon group.

[0074] In the embodiments of this application, saturated hydrocarbon groups include branched alkyl, straight alkyl, cycloalkyl, etc., and unsaturated hydrocarbon groups include straight alkenyl, straight alkenyl, branched alkyne, straight alkyne, cycloalkenyl, cycloalkyne, aryl, etc.

[0075] By way of non-limiting example, the number of carbon atoms in the saturated hydrocarbon groups of C1-10 and in the saturated hydrocarbon groups of substituted C1-10 are 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0076] For example, the saturated hydrocarbon groups of C1-10 and the saturated hydrocarbon groups of substituted C1-10 include, but are not limited to, methyl (-CH3), ethyl (-C2H5), n-propyl (-CH2CH2CH3), n-butyl (CH3-CH2-CH2-CH2-), and n-pentyl (-CH2-CH2-CH2-CH2-CH3). One of them.

[0077] By way of non-limiting example, the number of carbon atoms in the unsaturated hydrocarbon group of C2-10 and the unsaturated hydrocarbon group of substituted C2-10 are 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0078] For example, the unsaturated hydrocarbon groups in C2-10 and the unsaturated hydrocarbon groups in substituted C2-10 include, but are not limited to, vinyl (CH2=CH-), propenyl (-CH=CH-CH3), ethynyl (CH≡C-), and 2-propynyl (HC≡CCH2-). One of them.

[0079] As a preferred example, at least one of R2 and R3 contains an unsaturated hydrocarbon group with a C=C bond of C2-10.

[0080] As a more preferred example, R3 contains an unsaturated hydrocarbon group with C=C bonds of C2-10.

[0081] As a preferred example, at least one of R2' and R3' contains an unsaturated hydrocarbon group with a C=C bond of C2-10.

[0082] As a more preferred example, R3' contains an unsaturated hydrocarbon group with C=C bonds of C2-10.

[0083] In the embodiments of this application, when at least one of R2 and R3 in the compound shown in Formula I and the compound shown in Formula II contains a C2-10 unsaturated hydrocarbon group containing a C=C bond, and at least one of R2' and R3' contains a C2-10 unsaturated hydrocarbon group containing a C=C bond, and the compound shown in Formula I and the compound shown in Formula II contain a total of two C=C bonds, the compound shown in Formula I and the compound shown in Formula II can be called diene carboxylic acid, which has better polymerization performance under working conditions. When used in electrolyte, it can make the electrolyte have better pressure resistance characteristics.

[0084] In some embodiments, in the compounds shown in Formula I and / or Formula II, the substituents in the substituted C1-10 saturated hydrocarbon groups and the substituted C2-10 unsaturated hydrocarbon groups include, but are not limited to, at least one of ether groups, sulfone groups, sulfoxide groups, cyano groups, ester groups, hydroxyl groups, carbonyl groups, carboxyl groups, and amide groups.

[0085] In some embodiments, R1 and R1' are each independently selected from one of the following: hydrogen, a C1-10 straight-chain saturated hydrocarbon group, a C1-10 branched saturated hydrocarbon group, a substituted C1-10 straight-chain saturated hydrocarbon group, a substituted C1-10 branched saturated hydrocarbon group, a C2-10 straight-chain unsaturated hydrocarbon group, a C2-10 branched unsaturated hydrocarbon group, a substituted C2-10 straight-chain unsaturated hydrocarbon group, a substituted C2-10 branched unsaturated hydrocarbon group, a C3-10 saturated cyclic hydrocarbon group, a C3-10 unsaturated cyclic hydrocarbon group, a substituted C3-10 saturated cyclic hydrocarbon group, and a substituted C3-10 unsaturated cyclic hydrocarbon group.

[0086] As a preferred example, R1 and R1' are each independently selected from hydrogen, a C1-10 straight-chain saturated hydrocarbon group, a substituted C1-10 straight-chain saturated hydrocarbon group, a C2-10 straight-chain unsaturated hydrocarbon group, a substituted C2-10 straight-chain unsaturated hydrocarbon group, a three-membered ring saturated hydrocarbon group, a three-membered ring unsaturated hydrocarbon group, a four-membered ring saturated hydrocarbon group, a four-membered ring unsaturated hydrocarbon group, a five-membered ring saturated hydrocarbon group, a five-membered ring unsaturated hydrocarbon group, a six-membered ring saturated hydrocarbon group, a six-membered ring unsaturated hydrocarbon group, phenyl, etc.

[0087] In some embodiments, R2, R2', R3, and R3' are each independently selected from one of hydrogen, a C1-10 straight-chain saturated hydrocarbon group, a C2-10 straight-chain unsaturated hydrocarbon group, a C3-10 saturated cyclic hydrocarbon group, and a C3-10 unsaturated cyclic hydrocarbon group.

[0088] As a preferred example, R2, R2', R3, and R3' are each independently selected from one of the following: hydrogen, a C1-10 straight-chain saturated hydrocarbon group, a C2-10 straight-chain unsaturated hydrocarbon group, a three-membered ring saturated hydrocarbon group, a three-membered ring unsaturated hydrocarbon group, a four-membered ring saturated hydrocarbon group, a four-membered ring unsaturated hydrocarbon group, a five-membered ring saturated hydrocarbon group, a five-membered ring unsaturated hydrocarbon group, a six-membered ring saturated hydrocarbon group, a six-membered ring unsaturated hydrocarbon group, phenyl, etc.

[0089] As another preferred example, R1 and R1' are each independently selected from one of hydrogen, a substituted C1-10 saturated hydrocarbon group, and a substituted C2-10 unsaturated hydrocarbon group, and R3 and R3' are each independently selected from one of hydrogen, a C2-10 saturated hydrocarbon group, and a C2-10 unsaturated hydrocarbon group.

[0090] In some embodiments, the compound represented by Formula I is selected from at least one of compounds P1-P8:

[0091]

[0092] In some embodiments, the compound represented by Formula II is selected from at least one of compounds T1-T8:

[0093]

[0094] In some embodiments, the conjugated dienic acid comprises at least one of compounds having the structure shown in Formula III:

[0095]

[0096] X and Y are each independently selected from one of H, -R0-COOH, C1-10 saturated hydrocarbon group, substituted C1-10 saturated hydrocarbon group, C2-10 unsaturated hydrocarbon group, or substituted C2-10 unsaturated hydrocarbon group, and at least one of X and Y is -R0-COOH, where R0 represents a directly bonded or C1-10 saturated hydrocarbon group.

[0097] It should be noted that, in compounds having the structure shown in Formula III, except for -RO-COOH, the selection of other functional groups is similar to that in compounds shown in Formula I and / or Formula II. Taking C1-10 saturated hydrocarbon groups as an example, compounds having the structure shown in Formula III are similar to those in compounds shown in Formula I and / or Formula II, where the number of carbon atoms in the saturated hydrocarbon groups of C1-10 is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. Exemplary examples include, but are not limited to, methyl (-CH3), ethyl (-C2H5), n-propyl (-CH2CH2CH3), n-butyl (CH3-CH2-CH2-CH2-), and n-pentyl (-CH2-CH2-CH2-CH2-CH3). One of them. Therefore, the specific selection of substituted C1-10 saturated hydrocarbon groups, C2-10 unsaturated hydrocarbon groups, and substituted C2-10 unsaturated hydrocarbon groups in the compounds with the structure shown in Formula III will not be elaborated here.

[0098] In some implementations, the selection of saturated hydrocarbon groups of C1-10 in R0 can be similar to the selection of saturated hydrocarbon groups of C1-10 in X and Y, and will not be described in detail here.

[0099] In some embodiments, in compounds having the structure shown in Formula III, the substituents in the substituted C1-10 saturated hydrocarbon groups and the substituted C2-10 unsaturated hydrocarbon groups are selected from at least one of ether, sulfone, sulfoxide, cyano, ester, hydroxyl, carbonyl, carboxyl, and amide groups.

[0100] As a preferred example, the conjugated diene carboxylic acid includes, but is not limited to, at least one of 2,4-pentadienoic acid, sorbic acid, 2,4-hexadienoic acid, 5-phenyl-2,4-pentadienoic acid, and conjugated linoleic acid.

[0101] The electrolyte solute in the embodiments of this application can bring at least the following beneficial effects:

[0102] The electrolyte contains an olefinic cyclohexene carboxylic acid compound obtained by the reaction of conjugated diene carboxylic acids. This olefinic cyclohexene carboxylic acid compound contains multiple unsaturated hydrocarbon groups and carboxyl groups, and has a branched chain characteristic. This gives it good solubility in organic solvents in the electrolyte, low viscosity for easy wetting, and high flash voltage. Consequently, the electrolyte containing the olefinic cyclohexene carboxylic acid compound has the advantages of low viscosity, high conductivity, and excellent withstand voltage performance. After long-term high-temperature testing, the conductivity changes little, and the high-temperature stability is good, which can meet the requirements of low, medium, and high voltage aluminum electrolytic capacitors. In addition, the compounds shown in Formula I and Formula II have good low-temperature solubility. The electrolyte solution is clear and free of turbidity at -20°C, exhibiting good low-temperature stability and expanding its application range.

[0103] <Methods for preparing electrolyte solutes>

[0104] The method for preparing the electrolyte solute in this application embodiment can be used to prepare the electrolyte solute in this application embodiment. This method uses the aforementioned conjugated diene carboxylic acid as the main raw material to prepare the electrolyte solute. If necessary (e.g., when the polymerization rate of the conjugated diene carboxylic acid is too fast), a polymerization inhibitor can be added.

[0105] As an optional example, when the polymerization rate of conjugated dienic acid is low, the method for preparing the electrolyte solute in this application includes the following steps:

[0106] S101. The conjugated diene carboxylic acid is heated to react and the crude product is obtained.

[0107] In some embodiments, in step S101, the reaction temperature of the heating reaction is 80-250°C, including but not limited to 80°C, 90°C, 100°C, 150°C, 200°C or 250°C.

[0108] In some embodiments, in step S101, the reaction time of the heating reaction is 3-30 hours, including but not limited to 3 hours, 5 hours, 10 hours, 15 hours, 20 hours, 25 hours or 30 hours.

[0109] S102. The crude product is purified to obtain the olefinic cyclohexene carboxylic acid compound.

[0110] In some embodiments, the method for purifying the crude product in step S102 includes at least one of washing, vacuum distillation, etc. In the embodiments of this application, the purpose of purifying the crude product is to remove unreacted raw materials.

[0111] As another alternative example, when the polymerization rate of conjugated dienic acid is relatively fast, the method for preparing the electrolyte solute in this embodiment includes the following steps:

[0112] S201. Conjugated diene carboxylic acid is mixed with a polymerization inhibitor and then heated to react, yielding a crude product.

[0113] In some embodiments, in step S201, the reaction temperature of the heating reaction is 30-250°C, including but not limited to 30°C, 50°C, 100°C, 150°C, 200°C or 250°C.

[0114] In some embodiments, in step S201, the reaction time of the heating reaction is 3-30 hours, including but not limited to 3 hours, 5 hours, 10 hours, 15 hours, 20 hours, 25 hours or 30 hours.

[0115] In some embodiments, conjugated dienic acid and polymerization inhibitor are mixed in a molar ratio of 10:(0.001-1).

[0116] For example, the molar ratio of conjugated dienic acid to the polymerization inhibitor includes, but is not limited to, 10:0.001, 10:0:01, 10:0.1, 10:0.25, 10:0.5, 10:0.75, or 10:1.

[0117] In some embodiments, the polymerization inhibitor includes, but is not limited to, at least one of piperidinol oxide, 2-tert-butylhydroquinone, hydroquinone, etc.

[0118] S202. The crude product is purified to obtain the cyclohexene carboxylic acid compound.

[0119] In some embodiments, the method for purifying the crude product in step S202 includes at least one of washing, vacuum distillation, etc. In the embodiments of this application, the purpose of purifying the crude product is to remove unreacted raw materials.

[0120] The method for preparing the electrolyte solute in this application embodiment is simple; at the same time, when the compound having the structure shown in Formula III contains only one carboxyl group, since the monocarboxylic acid is converted into a dicarboxylic acid through the heated DA reaction, there is no need for oxidation ring-opening reactions, which is safe and does not require the reaction to be carried out at low temperature, making the operation convenient and easy to implement.

[0121] <Application of Electrolyte Solutes>

[0122] The electrolyte solutes of this application embodiment or the electrolyte solute preparation method of this application embodiment can be widely used in electrolytic capacitors, especially as a component of the electrolyte of electrolytic capacitors.

[0123] For example, the electrolytic capacitors mentioned above include, but are not limited to, low-voltage aluminum electrolytic capacitors, medium-voltage aluminum electrolytic capacitors, and high-voltage aluminum electrolytic capacitors.

[0124] In some embodiments, the electrolyte includes the electrolyte solute of the present application embodiments or the electrolyte solute prepared by the preparation method of the electrolyte solute of the present application embodiments, organic solvent, waterproofing agent, hydrogen scavenging agent, and flash voltage booster.

[0125] In some embodiments, the mass content of the electrolyte solute in the electrolyte is 1-20%, including but not limited to 1%, 2.5%, 5%, 7.5%, 10%, 12.5%, 15%, 17.5% or 20%.

[0126] In some embodiments, the organic solvent includes, but is not limited to, at least one of alcohol solvents, alcohol ether solvents, γ-butyrolactone, butyl acetate, etc., preferably an alcohol solvent.

[0127] For example, alcohol solvents include, but are not limited to, at least one of ethylene glycol, diethylene glycol, propylene glycol, glycerol, n-butanol, n-octanol, and polyethylene glycol.

[0128] For example, alcohol ether solvents include, but are not limited to, at least one of ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether.

[0129] It should be noted that when two or more of the above organic solvents are selected from alcohol solvents, alcohol ether solvents, γ-butyrolactone, and butyl acetate, the multiple substances can be mixed in any mass ratio.

[0130] In some embodiments, the electrolyte further includes a pH adjuster for adjusting the pH of the electrolyte to 5-8, including but not limited to 5, 5.5, 6, 6.5, 7, 7.5 or 8.

[0131] As a preferred example, a pH adjuster is used to adjust the pH of the electrolyte for electrolytic capacitors to 6-8.

[0132] In some embodiments, the pH adjuster includes, but is not limited to, at least one of ammonia, organic amines, alkali metals, etc.

[0133] In some embodiments, the organic amine includes, but is not limited to, at least one of methylamine, ethylamine, propylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, methyldiethylamine, and ethylaminedimethylamine.

[0134] The following non-limiting embodiments further illustrate certain features of the present technology.

[0135] The compounds represented by Formula I and Formula II involved in the following embodiments are shown in Table 1.

[0136] Table 1 shows the compounds represented by Formula I and Formula II in each embodiment.

[0137]

[0138]

[0139]

[0140] The compounds involved in groups 21 and 22 are shown in Table 2.

[0141] The compounds involved in Groups 21 and 22 in Table 2

[0142]

[0143] The 300ml three-necked flasks with mechanical stirrers, condensers, and thermometers used in the following embodiments can be made in-house or obtained commercially.

[0144] I. Examples and Comparative Examples

[0145] Example 1

[0146] Preparation of solute A1: In a 300ml three-necked flask equipped with a mechanical stirrer, condenser, and thermometer, 112.00g (1mol) of sorbic acid and 0.85g (5mmol) of 2-tert-butylhydroquinone (2-THC) as a polymerization inhibitor were added. Under nitrogen protection, the mixture was heated to 150℃ until the materials melted, kept at this temperature for 40 hours, and then cooled. 200g of water was added for washing, the aqueous layer was poured off, and the water was removed by vacuum distillation to obtain the electrolyte solute product of this embodiment. A small sample of the electrolyte solute product of this embodiment was taken for liquid chromatography-mass spectrometry (LC-MS) testing.

[0147] Sample pretreatment: Take a small amount of the product sample of this embodiment and dissolve it in 50% liquid mass grade acetonitrile-water. It is slightly white. Then add ammonia water (ammonia water is about 0.008% in the whole system). It is clear and transparent. Then filter it with a 0.2μm filter membrane before testing.

[0148] Instrument model: Waters XEVO G2-XS QTof; Ion source: ESI; Injection volume: 1μL; Column model: ACQUITY UPCC HSS T3 1.8μm 2.1*150mm; Column temperature: 38℃; Ion source temperature: 150℃; Desolventizing temperature: 350℃; Desolventizing gas flow rate: 600L / h; Injection cone gas flow rate: 30L / h; Liquid chromatography-mass spectrometry scanning range: M / Z = 50~5000Da; Mobile phase: Conventional mobile phase; Test mode: Negative ion mode.

[0149] Liquid chromatography-mass spectrometry (mass spectrum as shown) Figure 1 As shown in the figure, in this embodiment, the target product compounds P1, P2, T1, and T2, which have 2 repeating units of sorbic acid in the electrolyte solute product, have an overall yield of 92%.

[0150] Example 2

[0151] Preparation of solute A2: 174.20 g (1 mol) of 5-phenyl-2,4-pentadienoic acid was added to a 300 ml three-necked flask equipped with a mechanical stirrer, condenser, and thermometer. Under the protection of inert nitrogen gas, the mixture was heated to 180 °C until the material melted. After stirring at this temperature for 20 h, the mixture was cooled, 200 g of water was added, and the mixture was heated. The water layer was poured off, and the water was removed by vacuum distillation to obtain the electrolyte solute product of this embodiment.

[0152] Liquid chromatography-mass spectrometry (LC-MS) analysis showed that the electrolyte solutes in this embodiment were the target product compounds P3, T3, P4, and T4, with an overall yield of 83%.

[0153] Example 3

[0154] Preparation of solute A3: 98.10 g (1 mol) of 2,4-pentadienoic acid was added to a 300 ml three-necked flask equipped with a mechanical stirrer, condenser and thermometer. The mixture was heated to 200 °C until the material melted. Under the protection of inert nitrogen gas, the mixture was kept at this temperature and stirred for 4 hours. After cooling, the unreacted raw materials were removed by vacuum distillation to obtain the electrolyte solute product of this embodiment.

[0155] Liquid chromatography-mass spectrometry (LC-MS) analysis showed that the electrolyte solutes in this embodiment were the target product compounds P5, P6, T5, and T6, with an overall yield of 85%.

[0156] Example 4

[0157] Preparation of solute A4: In a 500ml three-necked flask equipped with a mechanical stirrer, condenser, and thermometer, 98.10g (1mol) of 2,4-pentadienoic acid and 174.20g (1mol) of 5-phenyl-2,4-pentadienoic acid were added. Under inert gas protection, the mixture was heated to 180℃ until the materials melted. After stirring at this temperature for 16 hours, the mixture was cooled, 300g of water was added, and the mixture was heated. The water layer was poured off, and the water was removed by vacuum distillation to obtain the product of this embodiment.

[0158] Liquid chromatography-mass spectrometry (LC-MS) analysis showed that the electrolyte solutes in this embodiment were the target product compounds P7, P8, T7, and T8, with a yield of 76%.

[0159] II. Performance Testing

[0160] The solutes A1, A2, A3, and A4, as well as compounds D1 and D2, prepared above were added to different amounts of organic solvents and stirred. The mixture was then cooled to 40°C, and ammonia gas was introduced to adjust the pH, resulting in different groups of test samples. The selection of raw materials and parameter settings for each group of test samples are detailed in Table 3.

[0161] Table 3. Raw material selection and parameter selection for each group of test samples

[0162]

[0163]

[0164] 1. Conductivity and low-temperature solubility tests

[0165] The solubility of the test samples in each group in Table 3 was observed at -20℃, and the conductivity, flash voltage, and viscosity were tested. The test methods were as follows:

[0166] Conductivity testing method: At 30°C, the conductivity of the electrolyte solute in each application example and application comparison example was tested using a conductivity meter.

[0167] Flash voltage test method: At room temperature (25℃), the flash voltage of the electrolyte solute in each application example and application comparison example is tested using a flash voltage tester.

[0168] Viscosity test: At 30°C, the viscosity of the electrolyte solute in each application example and application comparison example was tested using a rotational viscometer.

[0169] 2. Thermal stability test

[0170] The test samples from each group in Table 3 were sealed in stainless steel bottles and kept at 115℃ for 1000 hours. The change in conductivity was then measured using a conductivity meter. The rate of change in conductivity was calculated as follows: (0h conductivity - 1000h conductivity) / 0h conductivity * 100%.

[0171] The results of conductivity, low-temperature solubility test and thermal stability test are shown in Table 4.

[0172] Table 4 Performance Test Results

[0173]

[0174] As can be seen from Table 4:

[0175] The flash voltage of the test samples corresponding to the electrolyte solutes in this application is above 479V, with the highest reaching 560V and most around 500V. Meanwhile, at the same concentration of 10%, the flash voltage of the test samples in groups 21-22 is at least nearly 60V lower than that of the test samples in groups 2, 7, 12 and 17 of this application.

[0176] Furthermore, at -20℃, the test samples corresponding to the electrolyte solutes of this application remained clear without turbidity, demonstrating good low-temperature stability. Compared with the test samples of groups 21 and 22 corresponding to compounds D1 and D2, the conductivity and viscosity were similar. High viscosity makes it difficult to impregnate the capacitor with electrolyte during manufacturing.

[0177] Furthermore, the conductivity change rate of the test samples corresponding to the electrolyte solutes in this application was small after being kept at 115°C for 1000 hours, indicating good thermal stability. With the same concentration of 10%, the conductivity change rate of the test samples in groups 2, 7, 12, and 17 of this application after being kept at 115°C for 1000 hours was below 40.2%, which is at least 14% lower than that of the test samples in groups 21-22.

[0178] In summary, the electrolyte solute in the embodiments of this application has good flash voltage and conductivity, as well as good high and low temperature performance, making it suitable for preparing low, medium and high voltage aluminum electrolytic capacitors.

[0179] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0180] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An electrolyte solute, characterized by, This includes olefinic cyclohexene carboxylic acid compounds, which are obtained by the reaction of conjugated diene carboxylic acids.

2. The electrolyte solute according to claim 1, characterized in that, The olefinic cyclohexene carboxylic acid compound includes at least one of the compounds shown in Formula I and Formula II. R1 and R1' are each independently selected from one of hydrogen, a C1-10 saturated hydrocarbon group, a substituted C1-10 saturated hydrocarbon group, a C2-10 unsaturated hydrocarbon group, and a substituted C2-10 unsaturated hydrocarbon group; R2, R2', R3, and R3' are each independently selected from one of hydrogen, a C1-10 saturated hydrocarbon group, and a C2-10 unsaturated hydrocarbon group, and at least one of R2 and R3 contains a C2-10 unsaturated hydrocarbon group, and at least one of R2' and R3' contains a C2-10 unsaturated hydrocarbon group.

3. The electrolyte solute according to claim 1, characterized in that, The conjugated dienic acid includes at least one of the compounds having the structure shown in Formula III: X and Y are each independently selected from one of H, -R0-COOH, C1-10 saturated hydrocarbon group, substituted C1-10 saturated hydrocarbon group, C2-10 unsaturated hydrocarbon group, or substituted C2-10 unsaturated hydrocarbon group, and at least one of X and Y is -R0-COOH, where R0 represents a directly bonded or C1-10 saturated hydrocarbon group.

4. The electrolyte solute according to claim 3, characterized in that, The substituents in the substituted C1-10 saturated hydrocarbon groups and the substituted C2-10 unsaturated hydrocarbon groups are all selected from at least one of ether, sulfone, sulfoxide, cyano, ester, hydroxyl, carbonyl, carboxyl, and amide groups.

5. The electrolyte solute according to claim 3, characterized in that, The conjugated diene carboxylic acid includes at least one of 2,4-pentadienoic acid, sorbic acid, 2,4-hexadienoic acid, 5-phenyl-2,4-pentadienoic acid, and conjugated linoleic acid.

6. The electrolyte solute according to claim 2, wherein At least one of R2 and R3 contains a C2-10 unsaturated hydrocarbon group with a C=C bond, preferably R3 contains a C2-10 unsaturated hydrocarbon group with a C=C bond; and / or, At least one of R2' and R3' contains a C2-10 unsaturated hydrocarbon group with a C=C bond, preferably R3' contains a C2-10 unsaturated hydrocarbon group with a C=C bond; and / or, The substituents in the substituted C1-10 saturated hydrocarbon groups and the substituted C2-10 unsaturated hydrocarbon groups are all selected from at least one of ether, sulfone, sulfoxide, cyano, ester, hydroxyl, carbonyl, carboxyl, and amide groups.

7. The electrolyte solute according to claim 2, wherein R1 and R1' are each independently selected from one of the following: hydrogen, a C1-10 straight-chain saturated hydrocarbon group, a C1-10 branched saturated hydrocarbon group, a substituted C1-10 straight-chain saturated hydrocarbon group, a substituted C1-10 branched saturated hydrocarbon group, a C2-10 straight-chain unsaturated hydrocarbon group, a C2-10 branched unsaturated hydrocarbon group, a substituted C2-10 straight-chain unsaturated hydrocarbon group, a substituted C2-10 branched unsaturated hydrocarbon group, a C3-10 saturated cyclic hydrocarbon group, a C3-10 unsaturated cyclic hydrocarbon group, a substituted C3-10 saturated cyclic hydrocarbon group, and a substituted C3-10 unsaturated cyclic hydrocarbon group; and / or, R2, R2', R3, and R3' are each independently selected from one of the following: hydrogen, a C1-10 straight-chain saturated hydrocarbon group, a C2-10 straight-chain unsaturated hydrocarbon group, a C3-10 saturated cyclic hydrocarbon group, and a C3-10 unsaturated cyclic hydrocarbon group. Preferably, the compound represented by Formula I is selected from at least one of compounds P1-P8: ; and / or, The compound represented by Formula II is selected from at least one of compounds T1-T8:

8. A method for preparing an electrolyte solute as described in any one of claims 1 to 7, characterized in that, include: The crude product is obtained by heating conjugated dienic acid or by mixing conjugated dienic acid with a polymerization inhibitor and then heating it. The crude product was purified to obtain the olefinic cyclohexene carboxylic acid compound.

9. The preparation method according to claim 8, characterized in that, The heating reaction temperature is 80-250℃; and / or, The reaction time for the heating reaction is 3-50 hours; and / or, The conjugated dienic acid and the polymerization inhibitor are mixed in a molar ratio of 10:(0.001-1); and / or, The polymerization inhibitor includes at least one of piperidinol oxide, 2-tert-butylhydroquinone, and hydroquinone.

10. The application of the electrolyte solute as described in any one of claims 1 to 7 or the electrolyte solute prepared by the preparation method as described in claim 8 or 9 in the electrolyte.

Images