Phosphorus-free low-voltage electrolyte and preparation method thereof

Abstract

The invention relates to a non-phosphorus low-voltage electrolyte and a preparation method thereof. The non-phosphorus low-voltage electrolyte is prepared from the following raw materials in parts by weight: 9 to 15 parts of ethylene glycol, 13 to 18 parts of ammonium adipate, 0.5 to 3 parts of ammonium p-nitrobenzoate, 1 to 3 parts of citric acid, 1 to 3 parts of ammonium formate, 0.4 to 8 parts of p-tert-butylcatechol and 62 to 68 parts of water. The non-phosphorus low-voltage electrolyte is prepared by matching the p-tert-butylcatechol with the ethylene glycol, the ammonium adipate, the ammonium p-nitrobenzoate, the citric acid, the ammonium formate and other raw materials, and the p-tert-butylcatechol can effectively play a role in corrosion prevention in the high-water-content electrolyte and can reduce pollution to the environment; the prepared non-phosphorus low-voltage electrolyte is a dephosphorization product, is environment-friendly, and has the advantages of long service life and good use performance. The preparation method of the non-phosphorus low-voltage electrolyte is simple in process, convenient to operate and high in production efficiency, the prepared non-phosphorus low-voltage electrolyte product is stable in quality, and industrial production is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolytes, and in particular to a phosphorus-free low-voltage electrolyte and a preparation method thereof. Background Art

[0002] At present, aluminum electrolytic capacitors, as an important basic electronic component, are widely used in industries such as computers, automotive electronics, and household appliances. With the development of the economy and the advancement of technology, the performance and quality of electronic products are constantly improving, and people have put forward higher requirements on the performance of aluminum electrolytic capacitors. In the prior art, a certain amount of phosphide is often added to the electrolyte to meet the performance requirements of the product. However, due to the widespread use of phosphides, a large amount of phosphorus is easily discharged, which pollutes the environment, such as causing eutrophication of water bodies, and has a significant impact on the human body and the environment. With the continuous enhancement of people's environmental awareness and the increasing attention to environmental issues, it is of great significance to develop a phosphorus-free low-voltage electrolyte to reduce environmental pollution and make the product have good durability and performance. Summary of the invention

[0003] In order to solve the above-mentioned deficiencies in the prior art, one of the objects of the present invention is to provide a phosphorus-free low-voltage electrolyte, which is a dephosphorized product, can reduce pollution to the environment, and has the advantages of long service life and good performance.

[0004] Another object of the present invention is to provide a method for preparing a phosphorus-free low-voltage electrolyte. The method for preparing the phosphorus-free low-voltage electrolyte has a simple process, is easy to operate, and has high production efficiency. The quality of the prepared phosphorus-free low-voltage electrolyte product is stable, and it is conducive to industrial production.

[0005] The purpose of the present invention is achieved through the following technical scheme: a phosphorus-free low-voltage electrolyte, comprising the following raw materials in parts by weight: 9-15 parts of ethylene glycol, 13-18 parts of ammonium adipate, 0.5-3 parts of ammonium p-nitrobenzoate, 1-3 parts of citric acid, 1-3 parts of ammonium formate, 0.4-8 parts of p-tert-butylcatechol, and 62-68 parts of water.

[0006] Furthermore, the phosphorus-free low-voltage electrolyte comprises the following raw materials in parts by weight: 9.5-14 parts of ethylene glycol, 13-18 parts of ammonium adipate, 1-2 parts of ammonium p-nitrobenzoate, 1-3 parts of citric acid, 1-3 parts of ammonium formate, 0.5-5 parts of p-tert-butylcatechol, and 62-68 parts of water.

[0007] Furthermore, the phosphorus-free low-voltage electrolyte comprises the following raw materials in parts by weight: 9.5-12.5 parts of ethylene glycol, 13-18 parts of ammonium adipate, 1-2 parts of ammonium p-nitrobenzoate, 1.5-2.5 parts of citric acid, 1.5-2.5 parts of ammonium formate, 2-5 parts of p-tert-butylcatechol, and 62-68 parts of water.

[0008] The phosphorus-free low-voltage electrolyte of the present invention is a dephosphorized product, which can effectively reduce the pollution to the environment and has the advantages of long service life and good performance. The structural formula of tert-butylcatechol (TBC) is as follows:

[0009] From the above molecular structure, it can be seen that p-tert-butylcatechol has two adjacent hydroxyl groups, which can form a complex with aluminum ions on the surface of alumina, and p-tert-butyl can well shield the contact between water and the oxide film, thereby playing a good anti-corrosion effect. The present invention creatively adds p-tert-butylcatechol and combines it with raw materials such as ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid and ammonium formate to prepare a phosphorus-free low-voltage electrolyte, which can effectively play an anti-corrosion role in high-water electrolytes and reduce pollution to the environment. At the same time, the phosphorus-free low-voltage electrolyte has good performance and durability, good anti-corrosion effect, and has achieved better technical effects.

[0010] Another object of the present invention is achieved by the following technical solution: A method for preparing the above-mentioned phosphorus-free low-voltage electrolyte comprises the following steps: (1) Take ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, p-tert-butylcatechol and water in proportion; (2) Ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, p-tert-butylcatechol and water are uniformly mixed to obtain a phosphorus-free low-voltage electrolyte.

[0011] Furthermore, the p-tert-butylcatechol is pretreated before use, and the pretreatment method of the p-tert-butylcatechol comprises the following steps: A1. Mix tert-butyl catechol and water in a weight ratio of 1-2:3-4 and heat until the solution is clear. A2. Stir the solution obtained in step A1, cool it, centrifuge it to dry it, and vacuum dry it to obtain pretreated p-tert-butylcatechol.

[0012] Furthermore, in the step A1, p-tert-butylcatechol and water are mixed evenly in a weight ratio of 1-2:3-4, stirred in a reaction kettle, and heated to 75-80° C. until the solution is clear.

[0013] Furthermore, in the step A2, the solution obtained in the step A1 is stirred for 20-60 minutes, then cooled to 35-45° C., centrifuged and dried under vacuum to obtain pretreated p-tert-butylcatechol.

[0014] Furthermore, in the step (2), ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, and p-tert-butylcatechol are added to water and stirred evenly at a temperature of 80-92° C. to obtain a phosphorus-free low-voltage electrolyte.

[0015] The beneficial effects of the present invention are as follows: the present invention prepares a phosphorus-free low-voltage electrolyte by combining tert-butyl catechol with raw materials such as ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid and ammonium formate, and tert-butyl catechol can effectively play an anti-corrosion role in highly aqueous electrolytes and reduce environmental pollution; the prepared phosphorus-free low-voltage electrolyte is a dephosphorized product, which is environmentally friendly and has the advantages of long service life and good performance. The preparation method of the phosphorus-free low-voltage electrolyte is simple in process, easy to operate, and has high production efficiency. The prepared phosphorus-free low-voltage electrolyte product has stable quality and is conducive to industrial production. DETAILED DESCRIPTION

[0016] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments, and the contents mentioned in the implementation modes are not intended to limit the present invention.

[0017] In some embodiments of the present invention, a phosphorus-free low-voltage electrolyte includes the following raw materials in parts by weight: 9-15 parts of ethylene glycol, 0.5-3 parts of ammonium p-nitrobenzoate, 1-3 parts of citric acid, 1-3 parts of ammonium formate, 0.4-8 parts of p-tert-butylcatechol, and 62-68 parts of water.

[0018] In some embodiments of the present invention, the phosphorus-free low-voltage electrolyte includes the following raw materials in parts by weight: 9.5-14 parts of ethylene glycol, 13-18 parts of ammonium adipate, 1-2 parts of ammonium p-nitrobenzoate, 1-3 parts of citric acid, 1-3 parts of ammonium formate, 0.5-5 parts of p-tert-butylcatechol, and 62-68 parts of water.

[0019] In some embodiments of the present invention, the phosphorus-free low-voltage electrolyte includes the following raw materials in parts by weight: 9.5-12.5 parts of ethylene glycol, 13-18 parts of ammonium adipate, 1-2 parts of ammonium p-nitrobenzoate, 1.5-2.5 parts of citric acid, 1.5-2.5 parts of ammonium formate, 2-5 parts of p-tert-butylcatechol, and 62-68 parts of water.

[0020] In some embodiments of the present invention, a method for preparing the above-mentioned phosphorus-free low-voltage electrolyte comprises the following steps: (1) Take ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, p-tert-butylcatechol and water in proportion; (2) Ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, p-tert-butylcatechol and water are uniformly mixed to obtain a phosphorus-free low-voltage electrolyte.

[0021] In some embodiments of the present invention, the p-tert-butylcatechol is pretreated before use, and the pretreatment method of the p-tert-butylcatechol comprises the following steps: A1. Mix tert-butyl catechol and water in a weight ratio of 1-2:3-4 and heat until the solution is clear. A2. Stir the solution obtained in step A1, cool it, centrifuge it to dry it, and vacuum dry it to obtain pretreated p-tert-butylcatechol.

[0022] The existing commercially available tert-butyl catechol has a high impurity content. The present invention purifies the purchased tert-butyl catechol using the above steps to obtain electronic grade tert-butyl catechol.

[0023] In some embodiments of the present invention, in step A1, p-tert-butylcatechol and water are mixed uniformly in a weight ratio of 1-2:3-4, stirred in a reaction kettle, and heated to 75-80° C. until the solution is clear.

[0024] In some embodiments of the present invention, in step A2, the solution obtained in step A1 is stirred for 20-60 minutes, then cooled to 35-45° C., centrifuged and dried under vacuum to obtain pretreated p-tert-butylcatechol.

[0025] In some embodiments of the present invention, in step (2), ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, and p-tert-butylcatechol are added to water and stirred evenly at a temperature of 80-92° C. to obtain a phosphorus-free low-voltage electrolyte.

[0026] Example 1 In this embodiment, a phosphorus-free low-voltage electrolyte includes the following raw materials in parts by weight: 14 parts of ethylene glycol, 15 parts of ammonium adipate, 1.5 parts of ammonium p-nitrobenzoate, 2 parts of citric acid, 2 parts of ammonium formate, 0.5 parts of p-tert-butylcatechol, and 65 parts of water.

[0027] The method for preparing the above-mentioned phosphorus-free low-voltage electrolyte comprises the following steps: (1) Take ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, p-tert-butylcatechol and water in proportion; (2) Ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, p-tert-butylcatechol and water are uniformly mixed to obtain a phosphorus-free low-voltage electrolyte.

[0028] Furthermore, the p-tert-butylcatechol is pretreated before use, and the pretreatment method of the p-tert-butylcatechol comprises the following steps: A1. Mix tert-butylcatechol and water in a weight ratio of 3:7, stir in a reactor, and heat to 78°C until the solution is clear.

[0029] A2. Stir the solution obtained in step A1, cool it, centrifuge it to dry it, and vacuum dry it to obtain pretreated p-tert-butylcatechol.

[0030] Furthermore, in the step A2, the solution obtained in the step A1 is stirred for 30 minutes, then rapidly cooled to 40° C., centrifuged and dried under vacuum to obtain pretreated p-tert-butylcatechol.

[0031] Furthermore, in the step (2), ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, and p-tert-butylcatechol are added to water and stirred evenly at 85° C. to obtain a phosphorus-free low-voltage electrolyte.

[0032] Example 2 In this embodiment, a phosphorus-free low-voltage electrolyte includes the following raw materials in parts by weight: 13.5 parts of ethylene glycol, 15 parts of ammonium adipate, 1.5 parts of ammonium p-nitrobenzoate, 2 parts of citric acid, 2 parts of ammonium formate, 1 part of p-tert-butylcatechol, and 65 parts of water.

[0033] The method for preparing the above-mentioned phosphorus-free low-voltage electrolyte comprises the following steps: (1) Take ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, p-tert-butylcatechol and water in proportion; (2) Ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, p-tert-butylcatechol and water are uniformly mixed to obtain a phosphorus-free low-voltage electrolyte.

[0034] Furthermore, the p-tert-butylcatechol is pretreated before use, and the pretreatment method of the p-tert-butylcatechol comprises the following steps: A1. Mix tert-butylcatechol and water in a weight ratio of 3:7, stir in a reactor, and heat to 78°C until the solution is clear.

[0035] A2. Stir the solution obtained in step A1, cool it, centrifuge it to dry it, and vacuum dry it to obtain pretreated p-tert-butylcatechol.

[0036] Furthermore, in the step A2, the solution obtained in the step A1 is stirred for 30 minutes, then rapidly cooled to 40° C., centrifuged and dried under vacuum to obtain pretreated p-tert-butylcatechol.

[0037] Furthermore, in the step (2), ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, and p-tert-butylcatechol are added to water and stirred evenly at 85° C. to obtain a phosphorus-free low-voltage electrolyte.

[0038] Example 3 In this embodiment, a phosphorus-free low-voltage electrolyte includes the following raw materials in parts by weight: 12.5 parts of ethylene glycol, 15 parts of ammonium adipate, 1.5 parts of ammonium p-nitrobenzoate, 2 parts of citric acid, 2 parts of ammonium formate, 2 parts of p-tert-butylcatechol, and 65 parts of water.

[0039] The method for preparing the above-mentioned phosphorus-free low-voltage electrolyte comprises the following steps: (1) Take ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, p-tert-butylcatechol and water in proportion; (2) Ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, p-tert-butylcatechol and water are uniformly mixed to obtain a phosphorus-free low-voltage electrolyte.

[0040] Furthermore, the p-tert-butylcatechol is pretreated before use, and the pretreatment method of the p-tert-butylcatechol comprises the following steps: A1. Mix tert-butylcatechol and water in a weight ratio of 3:7, stir in a reactor, and heat to 78°C until the solution is clear.

[0041] A2. Stir the solution obtained in step A1, cool it, centrifuge it to dry it, and vacuum dry it to obtain pretreated p-tert-butylcatechol.

[0042] Furthermore, in the step A2, the solution obtained in the step A1 is stirred for 30 minutes, then rapidly cooled to 40° C., centrifuged and dried under vacuum to obtain pretreated p-tert-butylcatechol.

[0043] Furthermore, in the step (2), ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, and p-tert-butylcatechol are added to water and stirred evenly at 85° C. to obtain a phosphorus-free low-voltage electrolyte.

[0044] Example 4 In this embodiment, a phosphorus-free low-voltage electrolyte includes the following raw materials in parts by weight: 9.5 parts of ethylene glycol, 15 parts of ammonium adipate, 1.5 parts of ammonium p-nitrobenzoate, 2 parts of citric acid, 2 parts of ammonium formate, 5 parts of p-tert-butylcatechol, and 65 parts of water.

[0045] The method for preparing the above-mentioned phosphorus-free low-voltage electrolyte comprises the following steps: (1) Take ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, p-tert-butylcatechol and water in proportion; (2) Ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, p-tert-butylcatechol and water are uniformly mixed to obtain a phosphorus-free low-voltage electrolyte.

[0046] Furthermore, the p-tert-butylcatechol is pretreated before use, and the pretreatment method of the p-tert-butylcatechol comprises the following steps: A1. Mix tert-butylcatechol and water in a weight ratio of 3:7, stir in a reactor, and heat to 78°C until the solution is clear.

[0047] A2. Stir the solution obtained in step A1, cool it, centrifuge it to dry it, and vacuum dry it to obtain pretreated p-tert-butylcatechol.

[0048] Furthermore, in the step A2, the solution obtained in the step A1 is stirred for 30 minutes, then rapidly cooled to 40° C., centrifuged and dried under vacuum to obtain pretreated p-tert-butylcatechol.

[0049] Furthermore, in the step (2), ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, and p-tert-butylcatechol are added to water and stirred evenly at 85° C. to obtain a phosphorus-free low-voltage electrolyte.

[0050] Comparative Example 1 In this embodiment, a low-voltage electrolyte includes the following raw materials in parts by weight: 12.5 parts of ethylene glycol, 15 parts of ammonium adipate, 1.5 parts of ammonium p-nitrobenzoate, 2 parts of citric acid, 2 parts of ammonium formate, 2 parts of phosphoric acid, and 65 parts of water.

[0051] The method for preparing the low-voltage electrolyte comprises the following steps: (1) Take ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, phosphoric acid and water in proportion; (2) Add ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, and phosphoric acid into water and stir evenly at 85° C. to obtain a phosphorus-free low-voltage electrolyte.

[0052] The raw material ratios and conductivity of the phosphorus-free low-voltage electrolytes of Examples 1-4 and the phosphorus-containing low-voltage electrolyte of Comparative Example 1 are shown in Table 1 below:

[0053] Among them, the test method of conductivity includes the following steps: turn on the DDSJ-308A instrument switch, use HANAHI7030 standard solution to calibrate the instrument; take a beaker that has been washed with pure water and dried, take 100mL of the sample to be tested, and keep the temperature at 30±1℃; clean the test electrode and thermometer with pure water and wipe them dry with filter paper; put the measuring electrode and thermometer into the sample to be tested, when the temperature is 30℃, the value displayed by the instrument is the conductivity of the liquid to be tested; after the test, turn off the power, wash the thermometer and electrode rod with pure water, and store the electrode in a protective bottle.

[0054] The phosphorus-free low-voltage electrolytes of Examples 1-4 and the phosphorus-containing low-voltage electrolyte of Comparative Example 1 were respectively made into aluminum electrolytic capacitors of model 220μF / 25V, 08*12, and the performance of the capacitors was measured with reference to GB / T 5993-2003. After multiple measurements, the average value was taken, and the test data of 110℃ 2000h load is shown in Table 2 below:

[0055] Among them: the capacity difference before and after the test (ΔC / C0) and the loss angle tangent value (DF) are used to represent the service life of the electrolytic capacitor. ΔC / C0 = (capacitance after the test - capacitance before the test) / capacitance before the test. The smaller the ΔC / C0, the smaller the capacity decay; DF = ESR × W × C, where ESR is the equivalent series resistance, W = 2πf, f is the frequency of the AC power supply, C is the capacitance, and the smaller the loss angle tangent value, the smaller the capacitor heats up. The qualified judgment criteria are: ΔC / C < ± 20%, DF < 12%, LC (leakage current) < 250μA, appearance: no abnormality.

[0056] It can be seen from the above table that the phosphorus-free low-voltage electrolytes of Examples 1-4 of the present invention are dephosphorized products with good conductivity. While effectively reducing environmental pollution, the aluminum electrolytic capacitors produced have small capacity decay, long service life and better performance. Among them, by optimizing the dosage ratio of each raw material, Examples 3-4 can not only reduce phosphorus emissions, but also have smaller capacitor capacity decay and better durability compared with Comparative Example 1.

[0057] The aluminum electrolytic capacitors made of the phosphorus-free low-voltage electrolytes of Examples 1-4 and the phosphorus-containing low-voltage electrolyte of Comparative Example 1 were tested for 110° C. high-temperature storage performance parameters. The test data are shown in Table 3 below:

[0058] The above specific embodiments are further explanations of the technical solutions and beneficial effects of the present invention, and are not limitations of the implementation methods. For those skilled in the art, any obvious replacements that do not depart from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A phosphorus-free low-voltage electrolyte, characterized in that: The invention comprises the following raw materials in parts by weight: 9-15 parts of ethylene glycol, 13-18 parts of ammonium adipate, 0.5-3 parts of ammonium p-nitrobenzoate, 1-3 parts of citric acid, 1-3 parts of ammonium formate, 0.4-8 parts of p-tert-butylcatechol and 62-68 parts of water.

2. The phosphorus-free low-voltage electrolyte according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 9.5-14 parts of ethylene glycol, 13-18 parts of ammonium adipate, 1-2 parts of ammonium p-nitrobenzoate, 1-3 parts of citric acid, 1-3 parts of ammonium formate, 0.5-5 parts of p-tert-butylcatechol and 62-68 parts of water.

3. The phosphorus-free low-voltage electrolyte according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 9.5-12.5 parts of ethylene glycol, 13-18 parts of ammonium adipate, 1-2 parts of ammonium p-nitrobenzoate, 1.5-2.5 parts of citric acid, 1.5-2.5 parts of ammonium formate, 2-5 parts of p-tert-butylcatechol and 62-68 parts of water.

4. A method for preparing a phosphorus-free low-voltage electrolyte according to any one of claims 1 to 3, characterized in that: The steps include: (1) Take ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, p-tert-butylcatechol and water in proportion; (2) Ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, p-tert-butylcatechol and water are uniformly mixed to obtain a phosphorus-free low-voltage electrolyte.

5. The method for preparing a phosphorus-free low-voltage electrolyte according to claim 4, characterized in that: The p-tert-butylcatechol is pretreated before use, and the pretreatment method of the p-tert-butylcatechol comprises the following steps: A1. Mix tert-butyl catechol and water in a weight ratio of 1-2:3-4 and heat until the solution is clear. A2. Stir the solution obtained in step A1, cool it, centrifuge it to dry it, and vacuum dry it to obtain pretreated p-tert-butylcatechol.

6. The method for preparing a phosphorus-free low-voltage electrolyte according to claim 5, characterized in that: In the step A1, p-tert-butylcatechol and water are mixed uniformly in a weight ratio of 1-2:3-4, stirred in a reaction kettle, and heated to 75-80° C. until the solution is clear.

7. The phosphorus-free low-voltage electrolyte according to claim 4, characterized in that: In the step A2, the solution obtained in the step A1 is stirred for 20-60 minutes, then cooled to 35-45° C., centrifuged and dried under vacuum to obtain pretreated p-tert-butylcatechol.

8. The phosphorus-free low-voltage electrolyte according to claim 3, characterized in that: In the step (2), ethylene glycol, ammonium adipate, ammonium p-nitrobenzoate, citric acid, ammonium formate, and p-tert-butylcatechol are added to water and stirred evenly at a temperature of 80-92° C. to obtain a phosphorus-free low-voltage electrolyte.

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