Electrolyte for medium / high voltage aluminum electrolytic capacitor, and aluminum electrolytic capacitor

Abstract

An electrolyte for a medium / high voltage aluminum electrolytic capacitor, and an aluminum electrolytic capacitor, relating to the technical field of electrochemistry. The electrolyte comprises a solute, a solvent, and an additive; the solute comprises a cycloolefin carboxylic acid ammonium salt compound; the additive comprises an inorganic boron compound; the structural formula of the cycloolefin carboxylic acid ammonium salt compound is as shown in formula (1) or formula (2), wherein A is a hydrogen atom or one of a hydrocarbyl group, carboxyl group or ammonium carboxylate group containing 1-10 carbon atoms, B is a hydrogen atom or a hydrocarbyl group containing 1-10 carbon atoms, and the value of x+y is 0-30; the cycloolefin carboxylic acid ammonium salt compound and the inorganic boron compound are combined as an electrolyte, wherein the boron compound acts as a buffer to prevent the decomposition of the cycloolefin carboxylic acid ammonium salt compound.

Description

Electrolyte for medium and high voltage aluminum electrolytic capacitor and aluminum electrolytic capacitor Technical Field

[0001] The present application relates to the field of electrochemical technology, and in particular to an electrolyte for medium- and high-voltage aluminum electrolytic capacitors and an aluminum electrolytic capacitor. Background Art

[0002] Aluminum electrolytic capacitors are one of the fundamental components of electronic products and are widely used in the production of automotive electronics, frequency conversion technology, displays, chargers, electronic ballasts, switching power supplies, and energy-saving lamps. In recent years, the rapid development of electronic technology and the further improvement of the degree of integration have placed higher demands on the comprehensive performance of aluminum electrolytic capacitors, driving the development of aluminum electrolytic capacitors towards high voltage, high capacitance, and long life.

[0003] Aluminum electrolytic capacitors are mainly composed of capacitor cores and working electrolytes. The working electrolyte plays a key role in the performance of aluminum electrolytic capacitors, determining the operating temperature range, rated voltage, loss factor, impedance, rated ripple current, and working life of the capacitors.

[0004] Currently, the working electrolyte for medium- and high-voltage aluminum electrolytic capacitors is mostly a linear ammonium carboxylate + borate + ethylene glycol system. The more carbon atoms in a linear carboxylate, the higher the flash voltage. However, its solubility decreases sharply with increasing molecular weight. For example, the solubility of commonly used ammonium sebacate in ethylene glycol does not exceed 5%, and it is prone to crystallization at low temperatures, which limits the operating temperature range of the capacitor. Branched-chain polycarboxylates have relatively high solubility in polybasic solvents, are not prone to crystallization at low temperatures, have a wide operating temperature range, and offer high electrolyte conductivity. The resulting capacitors have strong withstand voltage and high ripple current capabilities. However, branched-chain polycarboxylates have the disadvantages of high cost and insufficient flash voltage performance. For example, at a 5% concentration, the flash voltage rarely exceeds 500V. In addition, other solutes that can be used as working electrolytes for medium and high voltage aluminum electrolytic capacitors include linear carboxylates such as ammonium azelaic acid, ammonium hydrogen azelaic acid, ammonium sebacate, and dodecanedioic acid, as well as ammonium pentaborate and ammonium benzoate. However, each of them has certain disadvantages, such as ammonium dodecanedioic acid is not easy to obtain, ammonium pentaborate has a relatively high conductivity, and ammonium benzoate is unstable at high temperatures.

[0005] Application Contents

[0006] To address the above technical issues, this application provides an electrolyte for medium- and high-voltage aluminum electrolytic capacitors and an aluminum electrolytic capacitor. The electrolyte, which uses a cycloolefin carboxylic acid ammonium salt compound as a solute and adds an inorganic boron compound as a buffer, is applied to the capacitor and exhibits enhanced thermal stability and long life. The specific technical solution is as follows:

[0007] An electrolyte for medium- and high-voltage aluminum electrolytic capacitors, comprising a solute, a solvent, and an additive, wherein the solute comprises a cycloolefin carboxylic acid ammonium salt compound, and the additive comprises an inorganic boron compound, wherein the cycloolefin carboxylic acid ammonium salt compound has a structural formula as shown in formula (1) or formula (2):

[0008] Where A is a hydrogen atom, a hydrocarbon group containing 1-10 carbon atoms, a carboxyl group, or an ammonium carboxylate group; B is a hydrogen atom or a hydrocarbon group containing 1-10 carbon atoms; x and y are integers, and the value of x + y is 0-30. Research has found that adding a boron-containing compound to the electrolyte as a buffer can prevent the decomposition of the cycloolefin carboxylate ammonium salt compound in high-temperature environments, thereby improving the high-temperature performance and life of the electrolyte.

[0009] The cycloolefin carboxylic acid ammonium salt can be obtained by reacting conjugated linoleic acid and its derivatives with an enophile compound through a Diels-Alder reaction, followed by hydrolysis, purification, and ammonia. The conjugated linoleic acid and its derivatives are selected from one of conjugated linoleic acid, conjugated linoleic acid methyl ester, conjugated linoleic acid ethyl ester, conjugated linoleic acid propyl ester, conjugated linoleic acid butyl ester, conjugated linoleic acid isopropyl ester, conjugated linoleic acid formamide, and conjugated linoleic acid acetamide; and the enophile compound is selected from one of acrylic acid and its derivatives, butenoic acid and its derivatives, pentenoic acid and its derivatives, methacrylic acid and its derivatives, maleic acid and its derivatives, maleic anhydride, citraconic acid and anhydride, and acrylonitrile.

[0010] Preferably, the cycloolefin carboxylate ammonium salt compound is selected from one of 4-hexyl-6-carboxylate ammonium-cyclohex-2-ene-1-octanoate, 4-hexyl-5,6-dicarboxylate ammonium-6 methyl-cyclohex-2-ene-1-octanoate, 4-hexyl-6-carboxylate ammonium-6 methyl-cyclohex-2-ene-1-octanoate, 6-propyl-1,3,5 tricarboxylate ammonium-cyclohex-2-ene and 4-hexyl-5-ethyl-6-carboxylate ammonium-cyclohex-2-ene-1-octanoate, and 4-hexyl-5-butyl-6-carboxylate ammonium-cyclohex-2-ene-1-octanoate.

[0011] Preferably, the inorganic boron compound is selected from one or more of boric acid, ammonium diborate, ammonium pentaborate and boric acid esters.

[0012] Preferably, the amount of the cycloolefin carboxylic acid ammonium salt compound added is 0.10-30.00% of the total amount of the electrolyte, preferably 0.50-15.00% by mass.

[0013] Preferably, the inorganic boron compound is added in an amount of 1.00-10.00% of the total amount of the electrolyte, preferably 2.00-5.00%.

[0014] Preferably, the solvent accounts for 60-95% of the total amount of the electrolyte, and the solvent is selected from one or more of alcohols, alcohol ethers, amides, sulfones, sulfoxides and esters; preferably, the solvent is ethylene glycol or γ-butyrolactone.

[0015] Preferably, the additives further include one or more of a waterproofing agent, a hydrogen scavenger, a flash enhancer, an anti-corrosion additive and a leakage current suppressant.

[0016] Preferably, the waterproofing agent is selected from one or more of hypophosphorous acid, phosphorous acid, phosphoric acid and monoalkyl phosphate, or one or more of ammonia or amine salts of hypophosphorous acid, phosphorous acid, phosphoric acid and monoalkyl phosphate;

[0017] Preferably, the hydrogen scavenger is selected from one or more of p-nitrophenol, p-nitrobenzyl alcohol, o-nitroanisole and m-nitroacetophenone;

[0018] Preferably, the flash fire enhancer is selected from one or more of silica melt, polyvinyl alcohols, polyethylene glycols, polyvinyl alcohol borate, polyvinyl alcohol phosphate, polyvinyl pyrrolidone and mannitol;

[0019] The anti-corrosion additive is selected from one or more of nitrilotriacetic acid, EDTA, silver benzoate and 8-hydroxyquinoline;

[0020] The leakage current inhibitor is selected from one or more of phosphotungstic acid, molybdotungstic acid, 3,5-dihydroxybenzoic acid and strontium nitrate.

[0021] Preferably, the amount of the waterproofing mixture added is 0.05-5.00% of the total amount of the electrolyte, preferably 0.10-3.00% by mass;

[0022] Preferably, the amount of the hydrogen remover added is 0.10-15.00% of the total amount of the electrolyte, preferably 0.20-4.00% by mass;

[0023] Preferably, the amount of the flash enhancer added is 0.20-15.00% of the total amount of the electrolyte, preferably 0.50-10.00% by mass;

[0024] Preferably, the amount of the anti-corrosion additive added is 0.01-5.00% of the total amount of the electrolyte, preferably 0.01-1.00% by mass;

[0025] Preferably, the amount of the leakage current inhibitor added is 0.01-5.00% of the total amount of the electrolyte, preferably 0.01-1.00%, by mass percentage.

[0026] Preferably, the electrolyte further comprises other organic carboxylic acids or ammonium salts thereof in addition to the cycloolefin carboxylic acid ammonium salt compound;

[0027] Other organic carboxylic acids or their ammonium salts are selected from one or more of sebacic acid, azelaic acid, benzoic acid, adipic acid, sebacic acid, dodecanedioic acid, 1,6-dodecanedioic acid, 1,7-decanedioic acid and the ammonium salts of the above acids, and their addition amount preferably accounts for 1.00-20.00% of the total amount of the electrolyte.

[0028] The present application also provides a medium- and high-voltage aluminum electrolytic capacitor using the above-mentioned electrolyte for aluminum electrolytic capacitors. Beneficial effects:

[0029] The beneficial effects of the technical solution of this application are as follows:

[0030] As electrolyte solutes, cycloolefin carboxylic acid ammonium salt compounds have good solubility, low-temperature antifreeze properties, and high electrical conductivity. When used in the electrolyte together with inorganic boron compounds, they also have good thermal stability and long life characteristics at high temperatures (especially 125°C). DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application are clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Therefore, the following detailed description of the embodiments of the present application is not intended to limit the scope of the application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0032] In this embodiment, a cycloolefin carboxylic acid ammonium salt compound is used as a solute, and an inorganic boron compound is added thereto as a buffering agent. The electrolyte formed is applied to capacitors and has higher thermal stability and long life. The specific embodiment is as follows:

[0033] An electrolyte for an aluminum electrolytic capacitor comprises a solute, a solvent, and an additive, wherein the solute comprises a cycloolefin carboxylic acid ammonium salt compound, and the additive comprises an inorganic boron compound, wherein the structural formula of the cycloolefin carboxylic acid ammonium salt compound is as shown in formula (1) or formula (2):

[0034] A is a hydrogen atom or a hydrocarbon group containing 1 to 10 carbon atoms, a carboxyl group, and an ammonium carboxylate group; B is a hydrogen atom or a hydrocarbon group containing 1 to 10 carbon atoms; x and y are integers, and the value of x+y is 0-30.

[0035] As a preferred embodiment, the cycloolefin carboxylate ammonium salt compound is selected from 4-hexyl-6-carboxylate ammonium-cyclohex-2-ene-1-octanoate ammonium, 4-hexyl-5,6-dicarboxylate ammonium-6 methyl-cyclohex-2-ene-1-octanoate ammonium, 4-hexyl-6-carboxylate ammonium-6 methyl-cyclohex-2-ene-1-octanoate ammonium, 6-propyl-1,3,5 tricarboxylate ammonium-cyclohex-2-ene and 4-hexyl-5-ethyl-6-carboxylate ammonium-cyclohex-2-ene-1-octanoate ammonium, 4-hexyl-5-butyl-6-carboxylate ammonium-cyclohex-2-ene-1-octanoate ammonium.

[0036] As a preferred embodiment, the inorganic boron compound is selected from one or more of boric acid, ammonium diborate, ammonium pentaborate and boric acid polyol ester.

[0037] As a preferred embodiment, the amount of the cycloolefin carboxylic acid ammonium salt compound added is 0.10-30.00% of the total amount of the electrolyte, preferably 0.50-15.00% by mass.

[0038] As a preferred embodiment, the inorganic boron compound is added in an amount of 1.00-10.00% of the total amount of the electrolyte, preferably 2.00-5.00%.

[0039] As a preferred embodiment, the solvent accounts for 60-95% of the total amount of the electrolyte by mass percentage, preferably 70-90%. The solvent is selected from one or more of alcohols, alcohol ethers, amides, sulfones, sulfoxides and esters; preferably, the solvent is ethylene glycol or r-butyrolactone.

[0040] As a preferred embodiment, the additive further includes one or more of a waterproofing agent, a hydrogen scavenger, a flash enhancer, an anti-corrosion additive, and a leakage current suppressant.

[0041] As a preferred embodiment, the waterproofing mixture is selected from one or more of hypophosphorous acid, phosphorous acid, phosphoric acid and monoalkyl phosphate, or one or more of ammonia or amine salts of hypophosphorous acid, phosphorous acid, phosphoric acid and monoalkyl phosphate;

[0042] As a preferred embodiment, the hydrogen scavenger is selected from one or more of p-nitrophenol, p-nitrobenzyl alcohol, o-nitroanisole and m-nitroacetophenone;

[0043] As a preferred embodiment, the flash fire enhancer is selected from one or more of silica melt, polyvinyl alcohol, polyethylene glycol, polyvinyl alcohol borate, polyvinyl alcohol phosphate, polyvinyl pyrrolidone and mannitol;

[0044] The anti-corrosion additive is selected from one or more of nitrilotriacetic acid, EDTA, silver benzoate and 8-hydroxyquinoline;

[0045] The leakage current inhibitor is selected from one or more of phosphotungstic acid, molybdotungstic acid, 3,5-dihydroxybenzoic acid and strontium nitrate.

[0046] As a preferred embodiment, the amount of the waterproof mixture added is 0.05-5.00% of the total amount of the electrolyte, preferably 0.10-3.00% by mass;

[0047] As a preferred embodiment, the amount of the hydrogen remover added is 0.10-15.00% of the total amount of the electrolyte, preferably 0.20-4.00% by mass;

[0048] As a preferred embodiment, the amount of the flash enhancer added is 0.20-15.00% of the total amount of the electrolyte, preferably 0.50-10.00% by mass;

[0049] As a preferred embodiment, the amount of the anti-corrosion additive added is 0.01-5.00% of the total amount of the electrolyte, preferably 0.01-1.00% by mass;

[0050] As a preferred embodiment, the amount of the leakage current inhibitor added is 0.01-5.00% of the total amount of the electrolyte, preferably 0.01-1.00%, by mass percentage.

[0051] As a preferred embodiment, the electrolyte further comprises other organic carboxylic acids or ammonium salts thereof in addition to the cycloolefin carboxylic acid ammonium salt compound;

[0052] Other organic carboxylic acids or their ammonium salts are selected from one or more of sebacic acid, azelaic acid, benzoic acid, adipic acid, sebacic acid, dodecanedioic acid, 1,6-dodecanedioic acid, 1,7-decanedioic acid and the ammonium salts of the above acids, and their addition amount preferably accounts for 1.00-20.00% of the total amount of the electrolyte.

[0053] This embodiment further provides an aluminum electrolytic capacitor using the above-mentioned electrolyte for an aluminum electrolytic capacitor.

[0054] The beneficial effects of the electrolyte in this application are further described below through several groups of examples and comparative examples.

[0055] Example 1:

[0056] Thermal stability test of olefin carboxylate ammonium salt compounds at 105°C

[0057] Preparation Method: The compound involved in formula (1) or formula (2) in this embodiment is dissolved in ethylene glycol to prepare a 5% concentration ethylene glycol solution, which is then sealed in a stainless steel bottle and kept at 105°C for a period of time. The changes in various parameters are shown in the following table:

[0058] Table 1 Conductivity changes after constant temperature at 105℃

[0059] From the above data, it can be concluded that the conductivity change value of the compound involved in formula (1) or formula (2) in this embodiment after being kept at a constant temperature of 105°C for a period of time is about -53%, while that of ammonium sebacate is about -74% and that of 2-hexylammonium adipate is about -46%. The results show that the stability of the compound involved in formula (1) or formula (2) is better than that of ammonium sebacate and inferior to that of 2-hexylammonium adipate.

[0060] Example 2:

[0061] Thermal stability test of olefin carboxylic acid ammonium salt compound and combination of olefin carboxylic acid ammonium salt compound and inorganic boron compound at 125°C

[0062] 1. Preparation of stock solution: dissolve the compound of formula (1) or formula (2) in this embodiment in ethylene glycol to prepare a 5% ethylene glycol solution, and seal it in a stainless steel bottle;

[0063] 2. Preparation of stock solution + 3% ammonium pentaborate: dissolve the compound involved in formula (1) or formula (2) in this embodiment and ammonium pentaborate in ethylene glycol to prepare an ethylene glycol solution of 5% cycloolefin carboxylic acid ammonium salt + 3% ammonium pentaborate, and seal the solution in a stainless steel bottle;

[0064] 3. The changes in various parameters of the electrolyte prepared by methods 1 and 2 above were observed when the temperature was kept constant at 125°C for a period of time. The details are shown in the following table:

[0065] Table 2 Conductivity change after constant temperature at 125℃ (change rate is compared between 2000h and 0h)

[0066] From the above data and phenomena, it can be concluded that the conductivity change rate of the compound solution involved in formula (1) or formula (2) in this embodiment is about -76% after being kept at a constant temperature of 125°C for a period of time, while after adding a certain amount of ammonium pentaborate, the conductivity change rate is about -17%, which is a very significant improvement.

[0067] Example 3:

[0068] Prepare electrolyte and conduct capacitor experimental tests

[0069] According to the proportions in Tables 3 and 4, a high-voltage electrolyte was prepared and the basic indicators were tested as shown in Table 5. Finally, a capacitor was made and tested for capacitance, leakage current, loss, ESR and other properties as shown in Table 6.

[0070] Table 3 Proportions of the components of the electrolytes of the embodiments and comparative examples

[0071] Table 4 Addition amount of each component in each embodiment and comparative example electrolyte

[0072] Table 5 Basic parameters of electrolyte

[0073] 500V electrolyte and device performance-life test results

[0074] The electrolytes in Examples 1 to 7 and Comparative Example 1 were used to make capacitors with specifications of 500v47035x50 and positive electrode foil of 700VF 0.47μF / cm 2 , negative electrode foil 2VF, electrolytic paper is domestic WD270-40+W180-30, and the cover is 33.8*3.0PP film.

[0075] The 500V electrolyte and device performance-life test results are shown in Table 6.

[0076] Table 6 125℃ ripple load life test results

[0077] As shown in Table 6, after the electrolytes in Examples 1 to 7 were made into capacitors, the basic parameters of capacitance, leakage current, loss and ESR changed little after a long-term ripple load life test. Compared with the comparative example 1 without adding the inorganic borate electrolyte, it has higher stability and passed the 125°C ripple life test for 1000h. After the life test, the capacitors were dissected and no abnormal conditions such as corrosion, breakdown, and hydration were found. However, the parameters of the comparative example without adding the inorganic boron compound changed greatly and exceeded the qualified range.

[0078] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. An electrolyte for medium and high voltage aluminum electrolytic capacitors, characterized in that: The invention comprises a solute, a solvent and an additive, wherein the solute comprises a cycloolefin carboxylic acid ammonium salt compound, and the additive comprises an inorganic boron compound, wherein the structural formula of the cycloolefin carboxylic acid ammonium salt compound is as shown in formula (1) or formula (2): A is a hydrogen atom or a hydrocarbon group containing 1 to 10 carbon atoms, a carboxyl group, or an ammonium carboxylate group; B is a hydrogen atom or a hydrocarbon group containing 1 to 10 carbon atoms; x and y are integers, and the value of x+y is 0-30.

2. The electrolyte for medium and high voltage aluminum electrolytic capacitors according to claim 1, characterized in that: The cycloolefin carboxylate ammonium salt compound is selected from 4-hexyl-6-carboxylate ammonium-cyclohex-2-ene-1-octanoic acid ammonium, 4-hexyl-5,6-dicarboxylate ammonium-6 methyl-cyclohex-2-ene-1-octanoic acid ammonium, 4-hexyl-6-carboxylate ammonium-6 methyl-cyclohex-2-ene-1-octanoic acid ammonium, 6-propyl-1,3,5 tricarboxylate ammonium-cyclohex-2-ene and 4-hexyl-5-ethyl-6-carboxylate ammonium-cyclohex-2-ene-1-octanoic acid ammonium, 4-hexyl-5-butyl-6-carboxylate ammonium-cyclohex-2-ene-1-octanoic acid ammonium.

3. The electrolyte for medium and high voltage aluminum electrolytic capacitors according to claim 1, characterized in that: The inorganic boron compound is selected from one or more of boric acid, ammonium diborate, ammonium pentaborate and boric acid esters.

4. The electrolyte for medium and high voltage aluminum electrolytic capacitors according to claim 1, characterized in that: Calculated by mass percentage, the amount of the cycloolefin carboxylic acid ammonium salt compound added accounts for 0.10-30.0% of the total amount of the electrolyte; the amount of the inorganic boron compound added accounts for 1.00-10.00% of the total amount of the electrolyte.

5. The electrolyte for medium and high voltage aluminum electrolytic capacitors according to claim 4, characterized in that: The amount of the cycloolefin carboxylic acid ammonium salt compound added is 0.50-15.00% of the total amount of the electrolyte; the amount of the inorganic boron compound added is 2.00-5.00% of the total amount of the electrolyte.

6. The electrolyte for medium and high voltage aluminum electrolytic capacitors according to claim 1, characterized in that: Calculated by mass percentage, the solvent accounts for 60.00-95.00% of the total amount of the electrolyte, and the solvent is selected from one or more of alcohols, alcohol ethers, amides, sulfones, sulfoxides and esters.

7. The electrolyte for medium and high voltage aluminum electrolytic capacitors according to claim 6, characterized in that: The solvent is selected from ethylene glycol or γ-butyrolactone.

8. The electrolyte for medium and high voltage aluminum electrolytic capacitors according to claim 1, characterized in that: The additives also include one or more of a waterproofing agent, a hydrogen scavenger, a flash enhancer, an anti-corrosion additive, and a leakage current inhibitor.

9. The electrolyte for medium and high voltage aluminum electrolytic capacitors according to claim 8, characterized in that: The waterproofing mixture is selected from one or more of hypophosphorous acid, phosphorous acid, phosphoric acid and monoalkyl phosphate, or selected from one or more of ammonium or amine salts of hypophosphorous acid, phosphorous acid, phosphoric acid and monoalkyl phosphate; The hydrogen remover is selected from one or more of p-nitrophenol, p-nitrobenzyl alcohol, o-nitroanisole and m-nitroacetophenone; The flash enhancer is selected from one or more of silica melt, polyvinyl alcohol, polyethylene glycol, polyvinyl alcohol borate, polyvinyl alcohol phosphate, polyvinyl pyrrolidone and mannitol; The anti-corrosion additive is selected from one or more of nitrilotriacetic acid, EDTA, silver benzoate and 8-hydroxyquinoline; The leakage current inhibitor is selected from one or more of phosphotungstic acid, molybdotungstic acid, 3,5-dihydroxybenzoic acid and strontium nitrate.

10. The electrolyte for medium and high voltage aluminum electrolytic capacitors according to claim 8, characterized in that: In terms of mass percentage, the amount of the waterproof mixture added accounts for 0.05-5.00% of the total amount of the electrolyte; In terms of mass percentage, the amount of hydrogen remover added accounts for 0.10-15.00% of the total amount of the electrolyte; In terms of mass percentage, the amount of the flash enhancer added is 0.20-15.00% of the total amount of the electrolyte; The amount of the anti-corrosion additive added is 0.01-5.00% of the total amount of the electrolyte in terms of mass percentage; Calculated by mass percentage, the amount of the leakage current inhibitor added accounts for 0.01-5.00% of the total amount of the electrolyte.

11. The electrolyte for medium and high voltage aluminum electrolytic capacitors according to claim 10, characterized in that: In terms of mass percentage, the amount of the waterproof mixture added accounts for 0.10-3.00% of the total amount of the electrolyte; In terms of mass percentage, the amount of hydrogen remover added accounts for 0.20-4.00% of the total amount of the electrolyte; In terms of mass percentage, the amount of the flash enhancer added is 0.50-10.00% of the total amount of the electrolyte; The amount of the anti-corrosion additive added is 0.01-1.00% of the total amount of the electrolyte in terms of mass percentage; Calculated by mass percentage, the amount of the leakage current inhibitor added accounts for 0.01-1.00% of the total amount of the electrolyte.

12. The electrolyte for medium and high voltage aluminum electrolytic capacitors according to claim 1, characterized in that: The electrolyte further includes other organic carboxylic acids or ammonium salts thereof in addition to the cycloolefin carboxylic acid ammonium salt compound.

13. The electrolyte for medium and high voltage aluminum electrolytic capacitors according to claim 12, characterized in that: The other organic carboxylic acids or their ammonium salts are selected from one or more of sebacic acid, azelaic acid, benzoic acid, adipic acid, sebacic acid, dodecanedioic acid, 1,6-dodecanedioic acid, 1,7-decanedioic acid and ammonium salts of the above acids.

14. The electrolyte for medium and high voltage aluminum electrolytic capacitors according to claim 12, characterized in that: The amount of the other organic carboxylic acid or its ammonium salt added is 1.00-20.00% of the total amount of the electrolyte.

15. A medium- and high-voltage aluminum electrolytic capacitor, characterized in that: Use the electrolyte for aluminum electrolytic capacitors as described in any one of claims 1 to 14.

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