Ultralow-temperature electrolyte, preparation method, and aluminum electrolytic capacitor provided with electrolyte

Abstract

Disclosed are an ultralow-temperature electrolyte, a preparation method, and an aluminum electrolytic capacitor provided with said electrolyte. The electrolyte comprises: 40-70 parts of a low-temperature solvent, 2-18 parts of an auxiliary solvent, 6-25 parts of a solute, 3-10 parts of a flash voltage improver, and 0.2-2.5 parts of an additive. The flash voltage improver is prepared by mixing ammoniated polystyrene anhydride, polydimethylformamide ester, and polyvinyl alcohol ester according to a ratio of 1:(0.5-2):(0.4-0.6); the low-temperature solvent is two or more of dimethylformamide, di-dimethyl formamide, 2-dimethyl formamide, diethylene glycol monobutyl ether, dimethylformamide butyl ether, dimethylformamide dibutyl ether, and propylene glycol; and the auxiliary solvent is two or more of γ-butyrolactone, tributyl phosphate, polydimethylsiloxane fatty acid ester, polydimethylsiloxane, methoxy polydimethylsiloxane, polyalkylene oxide polyol, polyvinyl alcohol, vinyl alcohol, and block polyether. The electrolyte provided in the present invention simultaneously exhibits high flash voltage and conductivity, and also has good stability.

Description

Ultra-low temperature electrolyte, preparation method and aluminum electrolytic capacitor having the same Technical Field

[0001] The present invention relates to the technical field of capacitors, and in particular to an ultra-low temperature electrolyte, a preparation method, and an aluminum electrolytic capacitor having the electrolyte. Background Art

[0002] At present, in order to meet the needs of new equipment, it is necessary to develop aluminum electrolytic capacitors with an operating voltage of 400V-450V to reduce the number of series connections. At the same time, in some areas, they can also replace more expensive film capacitors to meet market demand. However, domestic capacitors with a voltage exceeding 400V are still in an immature stage, especially for the development of products with an operating voltage of 400V-450V, which requires the development of corresponding high-stable electrolytes first.

[0003] Summary of the Invention

[0004] Based on the technical problems existing in the background technology, the present invention proposes an ultra-low temperature electrolyte, a preparation method and an aluminum electrolytic capacitor having the electrolyte. The electrolyte has both high flash voltage and conductivity and good stability.

[0005] The ultra-low temperature electrolyte proposed in the present invention comprises the following raw materials in parts by weight: 40-70 parts of a low-temperature solvent, 2-18 parts of an auxiliary solvent, 6-25 parts of a solute, 3-10 parts of a flash voltage enhancer, and 0.2-2.5 parts of an additive; wherein the flash voltage enhancer is a mixture of ammoniated polystyrene anhydride, polydimethylformamide ester, and polyvinyl alcohol ester in a ratio of 1:0.5-2:0.4-0.6.

[0006] Preferably, the low-temperature solvent is two or more of dimethylformamide, dimethylformamide, dimethylformamide, diethylene glycol monobutyl ether, dimethylformamide monobutyl ether, dimethylformamide dibutyl ether and propylene glycol.

[0007] Preferably, the auxiliary solvent is two or more of gamma-butyrolactone, tributyl phosphate, polydimethylformamide fatty acid ester, polydimethylformamide, methoxypolydimethylformamide, polyoxyalkylene polyol, polyvinyl alcohol, vinyl alcohol, and block polyether.

[0008] Preferably, the solute is two or more of 12-vinyl-8-octadecenediamonium, triphenylamine, dimethylamine, triethylamine, triethanolamine, mannitol, xylitol, sorbitol, tetradecanedioic acid, lauric acid, 2,7-di-n-butyl suberic acid, 2-ethylazelaic acid, citric acid, methylazelaic acid, tetracarboxylic acid, sucrose, gluconic acid, and phosphomolybdic acid.

[0009] Preferably, the additive is two or more of monobutyl phosphate, polydimethylformamide phosphate, o-nitroanisole, polyphosphoric acid, phosphotungstic acid, triethanolamine, ammonium hypophosphite, maleamide, dimethylamine, triethylamine, p-nitrobenzyl alcohol, and polyvinyl alcohol.

[0010] The method for preparing the ultra-low temperature electrolyte proposed in the present invention comprises the following steps:

[0011] S1: mixing the low-temperature solvent and the auxiliary solvent;

[0012] S2: Heat the S1 mixture, add the solute, and then increase the temperature to react;

[0013] S3: Add a flash voltage enhancer to the mixed solution after the S2 reaction, add additives after cooling, and mix well to obtain an ultra-low temperature electrolyte.

[0014] Preferably, the temperature of the mixed solution in S2 after heating is 85-100° C., the temperature of the temperature-raising reaction is 100-115° C., and the reaction time is 10-40 min.

[0015] Preferably, the temperature of the mixed liquid after cooling in S3 is 70-90°C.

[0016] The aluminum electrolytic capacitor proposed by the present invention comprises the above-mentioned ultra-low temperature electrolyte.

[0017] Beneficial technical effects of the present invention:

[0018] (1) The present invention provides a working electrolyte for 400V-450V ultra-low temperature aluminum electrolytic capacitors and a preparation method thereof. The electrolyte can be used in ultra-low temperature environments and has stable performance and good batch stability.

[0019] (2) The working electrolyte of the present invention has a high working voltage and a long service life (the service life of a 400V-450V product can reach 12,000 hours at 85°C); it also has a high flash voltage and electrical conductivity; the electrolyte also has good batch stability, a high aging yield rate, and good corrosion resistance.

[0020] (3) The flash voltage enhancer of the present invention is a mixture of ammoniated polystyrene anhydride, polydimethylformamide ester and polyvinyl alcohol ester in a certain proportion, which has a synergistic promoting effect on improving the flash voltage of the electrolyte, thereby ensuring that the flash voltage of the electrolyte of the present invention can be above 610V. DETAILED DESCRIPTION

[0021] The present invention will be further explained below with reference to specific embodiments.

[0022] Example 1

[0023] The ultra-low temperature electrolyte proposed in the present invention comprises the following raw materials in parts by weight: 55 kg of low-temperature solvent, 10 kg of auxiliary solvent, 15 kg of solute, 6 kg of flash voltage enhancer, and 1.2 kg of additives; wherein the flash voltage enhancer is a mixture of ammoniated polystyrene anhydride, polydimethylformamide ester, and polyvinyl alcohol ester in a ratio of 2:2:1.

[0024] Among them: the low-temperature solvent is 15 kg of polyglycerol ether, 15 kg of dimethylformamide, 15 kg of diethylene glycol monobutyl ether, and 10 kg of dimethylformamide.

[0025] The auxiliary solvents are 4 kg of tributyl phosphate, 3 kg of polyoxyalkylene polyol, and 3 kg of polydimethylformamide.

[0026] The solutes are 3 kg of tetracarboxylic acid, 2 kg of methyl azelaic acid, 2 kg of 12-vinyl-8-octadecenediamonium, 2 kg of 2-ethyl azelaic acid, 2 kg of dimethylamine, 2 kg of triethylamine, and 2 kg of sorbitol.

[0027] The additives are 0.2 kg of monobutyl phosphate, 0.1 kg of o-nitroanisole, 0.2 kg of ammonium hypophosphite, 0.2 kg of dimethylamine, 0.1 kg of triethylamine, 0.kg of polyvinyl alcohol, 0.1 kg of phosphotungstic acid, and 0.2 kg of polydimethylformamide phosphate.

[0028] The method for preparing the ultra-low temperature electrolyte proposed in the present invention comprises the following steps:

[0029] S1: mixing the low-temperature solvent and the auxiliary solvent;

[0030] S2: Heat the S1 mixture to 90°C, then add the solute and heat to 110°C with stirring. Keep stirring at 110°C and react for 25 minutes.

[0031] S3: Add a flash voltage enhancer to the mixed solution after the S2 reaction, and finally add additives when it is cooled to 80°C. After the preparation is completed, an ultra-low temperature electrolyte is obtained.

[0032] Example 2

[0033] The ultra-low temperature electrolyte proposed in the present invention comprises the following raw materials in parts by weight: 40 kg of low-temperature solvent, 2 kg of auxiliary solvent, 6 kg of solute, 3 kg of flash voltage enhancer, and 0.2 kg of additive; wherein the flash voltage enhancer is a mixture of ammoniated polystyrene anhydride, polydimethylformamide ester, and polyvinyl alcohol ester in a ratio of 10:5:4.

[0034] Wherein: the low temperature solvent is 10kg of dimethylformamide, 10kg of dimethylformamide, 10kg of diethylene glycol monobutyl ether, and 10kg of dimethylformamide dibutyl ether.

[0035] The auxiliary solvents are 0.5 kg of tributyl phosphate, 0.5 kg of polydimethylformamide fatty acid ester, 0.5 kg of methoxypolydimethylformamide, and 0.5 kg of polyoxyalkylene polyol.

[0036] The solutes are 1 kg of triethanolamine, 0.5 kg of mannitol, 0.5 kg of sorbitol, 1 kg of tetradecanedioic acid, 1 kg of 2,7-di-n-butyl suberic acid, 0.5 kg of 2-ethylazelaic acid, 0.5 kg of tetracarboxylic acid, and 1 kg of phosphomolybdic acid.

[0037] The additives are 0.04 kg of polydimethylformamide phosphate, 0.04 kg of o-nitroanisole, 0.04 kg of phosphotungstic acid, 0.04 kg of maleamide, and 0.04 kg of p-nitrobenzyl alcohol.

[0038] The method for preparing the ultra-low temperature electrolyte proposed in the present invention comprises the following steps:

[0039] S1: mixing the low-temperature solvent and the auxiliary solvent;

[0040] S2: Heat the S1 mixture to 85°C, then add the solute and stir and heat to 100°C. Keep stirring at 100°C for 10 minutes.

[0041] S3: Add a flash voltage enhancer to the mixed solution after the S2 reaction, and finally add additives when it cools to 70°C. After the preparation is completed, an ultra-low temperature electrolyte is obtained.

[0042] Example 3

[0043] The ultra-low temperature electrolyte proposed in the present invention comprises the following raw materials in parts by weight: 70 kg of low-temperature solvent, 18 kg of auxiliary solvent, 25 kg of solute, 10 kg of flash voltage enhancer, and 2.5 kg of additives; wherein the flash voltage enhancer is a mixture of ammoniated polystyrene anhydride, polydimethylformamide ester, and polyvinyl alcohol ester in a ratio of 1:2:0.6.

[0044] Among them: the low-temperature solvent is 20 kg of dimethylformamide, 20 kg of dimethylformamide, 15 kg of diethylene glycol monobutyl ether, and 15 kg of dimethylformamide monobutyl ether.

[0045] The auxiliary solvents are 6 kg of tributyl phosphate, 6 kg of polydimethylformamide fatty acid ester, and 6 kg of polydimethylformamide.

[0046] The solutes are 4 kg of triphenylamine, 3 kg of triethanolamine, 3 kg of dimethylamine, 3 kg of mannitol, 3 kg of xylitol, 3 kg of sorbitol, 3 kg of tetradecanedioic acid, and 3 kg of lauric acid.

[0047] The additives are 0.5 kg of monobutyl phosphate, 0.5 kg of polydimethylformamide phosphate, 0.5 kg of polyphosphoric acid, 0.5 kg of phosphotungstic acid, and 0.5 kg of maleamide.

[0048] The method for preparing the ultra-low temperature electrolyte proposed in the present invention comprises the following steps:

[0049] S1: mixing the low-temperature solvent and the auxiliary solvent;

[0050] S2: Heat the S1 mixture to 100°C, then add the solute and stir and heat to 115°C. Keep stirring at 115°C and react for 40 minutes.

[0051] S3: Add a flash voltage enhancer to the mixed solution after the S2 reaction, and finally add additives when it is cooled to 90°C. After the preparation is completed, an ultra-low temperature electrolyte is obtained.

[0052] Comparative Example 1

[0053] The flash voltage enhancer of this solution is a mixture of ammoniated polystyrene anhydride and polydimethylformamide in a ratio of 1:1, and the other conditions are the same as those in Example 1.

[0054] Comparative Example 2

[0055] The flash voltage enhancer of this solution is a mixture of ammoniated polystyrene anhydride and polyvinyl alcohol ester in a ratio of 2:1, and the other conditions are the same as those in Example 1.

[0056] Comparative Example 3

[0057] The flash voltage enhancer of this solution is a mixture of polydimethylformamide ester and polyvinyl alcohol ester in a ratio of 2:1, and the other conditions are the same as those in Example 1.

[0058] The parameters of the electrolytes prepared in Example 1 and Comparative Examples 1-3 were measured, and the results are shown in Table 1.

[0059] Table 1 Electrolyte parameter test results

[0060] It can be seen from the experimental data in Table 1 that the electrolyte prepared by the present invention has a higher flash voltage and conductivity, and the flash voltage enhancer of the present invention is a mixture of ammoniated polystyrene anhydride, polydimethylformamide ester and polyvinyl alcohol ester in a certain proportion, which has a synergistic promoting effect on improving the flash voltage of the electrolyte, thereby ensuring that the flash voltage of the electrolyte of the present invention can be above 610V.

[0061] In addition, in order to verify the low-temperature resistance of the electrolyte prepared in Example 1, the electrolyte in Example 1 was applied to a 400V-450V large-scale capacitor and a 400V-450V small-scale chip capacitor, respectively, and the low-temperature resistance characteristics of the capacitors were measured. The results are shown in Tables 2 and 3.

[0062] Table 2 Characteristics of 400V-450V large-capacitors (taking 400V-450V 2200μf as an example)

[0063] Table 3 Characteristics of 400V-450V small capacitors (taking 400V-450V 10μf as an example)

[0064] It can be seen from the test results in Table 2 and Table 3 that the 400V-450V large-scale capacitors and 400V-450V small-scale chip capacitors prepared with the electrolyte of the present invention both have excellent low-temperature resistance.

Claims

1. Ultra-low temperature electrolyte, characterized in that: The method comprises the following raw materials in parts by weight: 40-70 parts of low-temperature solvent, 2-18 parts of auxiliary solvent, 6-25 parts of solute, 3-10 parts of flash voltage enhancer and 0.2-2.5 parts of additive; wherein the flash voltage enhancer is prepared by mixing ammoniated polystyrene anhydride, polydimethylformamide ester and polyvinyl alcohol ester in a ratio of 1:0.5-2:0.4-0.

6.

2. The ultra-low temperature electrolyte according to claim 1, characterized in that: The low-temperature solvent is two or more of dimethylformamide, dimethylformamide, dimethylformamide, diethylene glycol monobutyl ether, dimethylformamide monobutyl ether, dimethylformamide dibutyl ether and propylene glycol.

3. The ultra-low temperature electrolyte according to claim 1, characterized in that: The auxiliary solvent is two or more of gamma-butyrolactone, tributyl phosphate, polydimethylformamide fatty acid ester, polydimethylformamide, methoxy polydimethylformamide, polyoxyalkylene polyol, polyvinyl alcohol, vinyl alcohol, and block polyether.

4. The ultra-low temperature electrolyte according to claim 1, characterized in that: The solute is two or more of 12-vinyl-8-octadecenediamonium, triphenylamine, triethanolamine, dimethylamine, triethylamine, mannitol, xylitol, sorbitol, tetradecanedioic acid, lauric acid, 2,7-di-n-butyl suberic acid, 2-ethyl azelaic acid, citric acid, methyl azelaic acid, tetracarboxylic acid, sucrose, gluconic acid, and phosphomolybdic acid.

5. The ultra-low temperature electrolyte according to claim 1, characterized in that: The additive is two or more of monobutyl phosphate, polydimethylformamide phosphate, o-nitroanisole, polyphosphoric acid, phosphotungstic acid, triethanolamine, ammonium hypophosphite, maleamide, dimethylamine, triethylamine, p-nitrobenzyl alcohol, and polyvinyl alcohol.

6. The method for preparing an ultra-low temperature electrolyte according to any one of claims 1 to 5, characterized in that: The steps are as follows: S1: mixing the low temperature solvent and the auxiliary solvent; S2: Heat the S1 mixture, add the solute and raise the temperature to react; S3: Add a flash voltage enhancer to the mixed solution after the S2 reaction, add additives after cooling, and mix well to obtain an ultra-low temperature electrolyte.

7. The method for preparing an ultra-low temperature electrolyte according to claim 6, characterized in that: The temperature of the mixed solution in S2 after heating is 85-100°C, the temperature of the temperature-raising reaction is 100-115°C, and the reaction time is 10-40 minutes.

8. The method for preparing an ultra-low temperature electrolyte according to claim 6, characterized in that: The temperature of the mixed liquid in S3 after cooling is 70-90°C.

9. An aluminum electrolytic capacitor, characterized in that Contains the ultra-low temperature electrolyte as described in any one of claims 1 to 5.

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