Electrolytic capacitor electrolyte, method for preparing the same, and capacitor using the same

Abstract

The application relates to an electrolyte for an electrolytic capacitor, a preparation method of the electrolyte and a capacitor using the electrolyte. The electrolyte for the electrolytic capacitor comprises the following components in parts by mass: 8-16 parts of an organic acid and an amine salt thereof, 1-8 parts of an inorganic acid and an amine salt thereof, 65-90 parts of an organic solvent, 0.5-2.5 parts of a hydrogen scavenger, 2-9 parts of a high-temperature stabilizer and 15-40 parts of a voltage endurance enhancer. The scheme provided by the application can effectively maintain the voltage endurance performance while improving the conductivity, has high stability in a high-temperature and high-pressure environment, has a long service life, effectively reduces an equivalent series resistance ESR when used in a high-voltage and large-ripple aluminum electrolytic capacitor, thereby reducing the volume of the capacitor and the volume of a power supply, accelerates the development process of the power supply in the direction of small volume, reduces the internal loss of the power supply, improves the precision of the power supply, and makes the current output more stable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrolyte, in particular to an electrolyte for electrolytic capacitor, a preparation method thereof and a capacitor using the same. BACKGROUND

[0002] Capacitors are irreplaceable basic elements in various electronic products, and are widely used in electronic devices including power supplies, mainboards, sound systems and uninterruptible power systems. As a common device in electronic circuits, capacitors play the roles of filtering, bypassing, coupling, decoupling and phase conversion. In recent years, with the rapid development of electronic component integration and high-speed processing technology, the global market has put forward higher requirements for the performance of capacitor products. Among them, as the most critical component in capacitors, aluminum electrolytic capacitors have become the development trend of small size, long life, high temperature resistance, high frequency ripple current resistance and low impedance.

[0003] High-voltage aluminum electrolytic capacitors are generally used in device power supply ends and mainly play a filtering role to maintain the relative stability of the current in the power supply bus to ensure the smooth operation of the back-end components. In a large power supply, the position of the aluminum electrolytic capacitor is usually large. The larger the power supply power is, the more the capacitors occupy the position, which has a certain inhibitory effect on the miniaturization of the power supply. Therefore, if the power supply is to be miniaturized, the performance of the capacitor must be optimized.

[0004] At present, there are many factors affecting the performance of capacitors. In addition to the manufacturing process level, the quality of the anode aluminum foil and other aspects, the electrolyte in the capacitor is an important constraint factor. The electrolyte is the actual cathode of the capacitor and plays an important role in providing oxygen ions and repairing the anode oxide film. It determines the working temperature range, rated voltage, loss factor, impedance, rated ripple current and working life of the capacitor. Therefore, the electrolyte generally requires high oxidation efficiency, stable physical and chemical properties, small resistivity and no corrosion to aluminum foil and sealing materials. In related technologies, the electrolyte of the aluminum electrolytic capacitor is mainly composed of a main solvent, a main electrolyte and an additive. The solvent determines the working temperature range of the capacitor and plays a key role in ion solvation. The main electrolyte provides ions to make the electrolyte conductive and have oxidation ability. However, the existing electrolyte has low conductivity (i.e. conductivity) and high equivalent series resistance (ESR) when applied in high-voltage and large-ripple aluminum electrolytic capacitors, which is not conducive to reducing the size of the capacitor. The conductivity of some electrolytes is high, but its voltage resistance performance is low and is not suitable for long-term high-voltage environment. It has poor stability and short service life.

[0005] Therefore, there is a need for an electrolyte for electrolytic capacitors that can effectively improve conductivity while maintaining voltage withstand performance, and has high stability and long service life in high temperature and high pressure environments. When used in high voltage, high ripple aluminum electrolytic capacitors, it can effectively reduce the equivalent series resistance (ESR), thereby reducing the size of the capacitor. Summary of the Invention

[0006] To overcome the problems existing in related technologies, this application provides an electrolyte for electrolytic capacitors, a method for preparing the same, and a capacitor using the same. The electrolyte for electrolytic capacitors, the method for preparing the same, and the capacitor using the same can effectively improve conductivity while maintaining voltage resistance, and have high stability in high temperature and high pressure environments, resulting in a long service life. When used in high-voltage, high-ripple aluminum electrolytic capacitors, it effectively reduces the equivalent series resistance (ESR), thereby reducing the size of the capacitor.

[0007] The first aspect of this application provides an electrolyte for electrolytic capacitors, comprising the following components by mass: 8-16 parts of organic acid and its amine salt, 1-8 parts of inorganic acid and its amine salt, 65-90 parts of organic solvent, 0.5-2.5 parts of hydrogen scavenger, 2-9 parts of high temperature stabilizer, 12-32 parts of voltage withstand booster, and 3-8 parts of second voltage withstand agent.

[0008] In one embodiment, the organic acid and its amine salt include at least one of: sebacic acid and its ammonium salt, dodecanoic acid and its ammonium salt, azelaic acid and its ammonium salt, stearic acid and its ammonium salt, octadecenoic acid and its ammonium salt, 1,7-sebacic acid and its ammonium salt, 2-methylammonium azelaate and eicosadiene dicarboxylic acid amine.

[0009] In one embodiment, the inorganic acid and its amine salt include at least one of boric acid and ammonium pentaborate.

[0010] In one embodiment, the organic solvent includes at least one of ethylene glycol, glycerol, butanediol, diethylene glycol, benzyl alcohol, oligoethylene glycol, and γ-butyrolactone.

[0011] In one embodiment, the hydrogen scavenger comprises at least one of p-nitrobenzoic acid, ammonium p-nitrobenzoate, p-nitroanisole, and p-nitrobenzyl alcohol.

[0012] In one embodiment, the high-temperature stabilizer comprises: a first stabilizer and a second stabilizer; the first stabilizer comprises at least one of phosphoric acid, mannitol, and citric acid; and the second stabilizer comprises at least one of phosphorous acid, hypophosphite, and butyl phosphate.

[0013] In an embodiment, the voltage endurance enhancer comprises: a first voltage endurance enhancer and a second voltage endurance enhancer; the first voltage endurance enhancer comprises at least one of polyvinyl alcohol, polyethylene glycol, polyvinyl alcohol ester, nano-silica and polyethylene glycol ester; the second voltage endurance enhancer comprises nano-silica.

[0014] In an embodiment, the organic acid and its amine salt comprises: 3-5 parts of sebacic acid and its ammonium salt, 1-3 parts of dodecanedioic acid and its ammonium salt, 1-3 parts of 1,7-decanedioic acid and its ammonium salt, and 3-5 parts of amine of eicosadiene dicarboxylic acid; the inorganic acid and its amine salt comprises 1-3 parts of boric acid; the organic solvent comprises 50-60 parts of ethylene glycol, 10-20 parts of glycerol and 5-10 parts of diethylene glycol; the hydrogen elimination agent comprises 0.5-2.5 parts of p-nitrobenzyl alcohol; the high-temperature stabilizer comprises 0.5-2 parts of phosphoric acid, 1-5 parts of mannitol and 0.5-2 parts of citric acid; the voltage endurance enhancer comprises 3-8 parts of polyvinyl alcohol, 3-8 parts of polyethylene glycol 2000, 3-8 parts of polyvinyl alcohol ester, 3-8 parts of polyethylene glycol ester and 3-8 parts of nano-silica.

[0015] The second aspect of the present application provides a preparation method of an electrolyte, specifically comprising the following steps:

[0016] The organic solvent and the inorganic acid are heated and mixed, heated to 160℃, and maintained for 120 min to obtain a first mixed solution;

[0017] The temperature of the first mixed solution is reduced to 140℃, and the organic acid and its amine salt, the inorganic acid amine salt, the first stabilizer and the first voltage endurance enhancer are added, and maintained for 60 min to obtain a second mixed solution;

[0018] The temperature of the second mixed solution is reduced to 105℃, and the second stabilizer and the hydrogen elimination agent are added, and maintained for 30 min to obtain a third mixed solution;

[0019] The temperature of the third mixed solution is reduced to 95℃, and the second voltage endurance enhancer is added, and maintained for 20 min, and then cooled to obtain the electrolyte for electrolytic capacitor described above.

[0020] The third aspect of the present application provides a high-voltage large-ripple aluminum electrolytic capacitor, which uses the electrolyte for electrolytic capacitor described above.

[0021] Compared with the prior art, the technical scheme provided by the present application can have the following beneficial effects:

[0022] (1) The conductivity of the electrolyte for electrolytic capacitor of the present application is about 45% higher than that of the commercially available electrolyte. The flashover voltage (equivalent to the withstand voltage) is also above 490V. The conductivity is effectively improved while the withstand voltage of the electrolyte is effectively maintained. The withstand voltage of the electrolyte does not decrease with the increase of the conductivity, which is suitable for high-voltage and large-ripple aluminum electrolytic capacitors.

[0023] (2) The electrolyte for electrolytic capacitor of the present application has a much lower decrease rate of conductivity change than that of the commercially available electrolyte after long-time high-temperature storage. It has high stability under high temperature.

[0024] (3) The electrolyte for electrolytic capacitor of the present application can basically achieve good results of each parameter of the electrolyte after 4000 hours of use after verification under high pressure, high temperature and large ripple current. Compared with the commercially available electrolyte, it has a longer service life.

[0025] (4) The preparation method of the electrolyte of the present application is simple and suitable for mass production and use.

[0026] (5) The high-voltage and large-ripple aluminum electrolytic capacitor using the electrolyte for electrolytic capacitor of the present application has significantly improved capacitor performance. The loss angle energy is decreased by more than 2 percentage points. The ESR of the capacitor is decreased by more than 30%. The ripple current bearing capacity is 1.5 times higher than that of other aluminum electrolytic capacitors. The volume of the power supply is effectively reduced, the process of developing small volume power supply is accelerated, the internal loss of the power supply is reduced, the precision of the power supply is improved, the output of the current is more stable, and the service life is longer.

[0027] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0028] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout the several views, and in which:

[0029] Figure 1 is a flowchart of the preparation method of the electrolyte according to the present application. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present application will be described in more detail with reference to the drawings. Although the preferred embodiments of the present application are shown in the drawings, it is to be understood that the present application can be carried out in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0031] The terminology used in the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used in the description of the application and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0032] It should be understood that although the terms "first", "second", "third" and the like can be employed in the present application to describe various information, these information should not be limited by these terms. These terms are only used to distinguish one piece of information from another piece of information. For example, the first information can also be referred to as the second information, and similarly, the second information can also be referred to as the first information without departing from the scope of the present application. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0033] However, when the existing electrolyte is applied in a high-voltage large-ripple aluminum electrolytic capacitor, the conductivity (i.e. the conductivity performance) of the electrolyte is low, the equivalent series resistance ESR is high, which is not conducive to reducing the volume of the capacitor, and the conductivity of some electrolytes is high, but the voltage resistance performance is low, which is not suitable for long-term high-voltage environment, and the stability is poor, and the service life is short.

[0034] In view of the above problems, the electrolyte for electrolytic capacitor provided by the embodiments of the present application can effectively improve the conductivity while maintaining the voltage resistance performance, and has high stability in high-temperature and high-voltage environment, and long service life. When used in a high-voltage large-ripple aluminum electrolytic capacitor, the equivalent series resistance ESR is effectively reduced, and the volume of the capacitor is reduced.

[0035] The electrolyte for electrolytic capacitor provided by the present application comprises the following components by mass fraction: 8-16 parts of organic acid and amine salt thereof, 1-8 parts of inorganic acid and amine salt thereof, 65-90 parts of organic solvent, 0.5-2.5 parts of hydrogen scavenger, 2-9 parts of high-temperature stabilizer, and 15-40 parts of voltage resistance enhancer.

[0036] In order to adapt to the characteristics of high-voltage large ripple aluminum electrolytic capacitors, the electrolyte mainly uses organic acid and its amine salt and inorganic acid and its amine salt, specifically:

[0037] The organic acid and its amine salt include at least one of sebacic acid and its ammonium salt, dodecanedioic acid and its ammonium salt, azelaic acid and its ammonium salt, stearic acid and its ammonium salt, octadecene diacid and its ammonium salt, 1,7-decanedioic acid and its ammonium salt, 2-methylazelaic acid ammonium (HS-02) and amine of eicosadiene dicarboxylic acid (HS-04), wherein the chemical formula of eicosadiene dicarboxylic acid is The inorganic acid and its amine salt include at least one of boric acid and ammonium pentaborate, wherein boric acid is an inorganic acid, and ammonium pentaborate is an inorganic acid amine salt; preferably, the organic acid and its amine salt include 1-3 parts of dodecanedioic acid and its ammonium salt, 3-5 parts of azelaic acid and its ammonium salt, and 3-5 parts of amine of eicosadiene dicarboxylic acid (HS-04) by mass fraction, and the inorganic acid and its amine salt include 1-3 parts of boric acid and 1-3 parts of ammonium pentaborate by mass fraction; more preferably, the organic acid and its amine salt include 3-5 parts of sebacic acid and its ammonium salt, 1-3 parts of dodecanedioic acid and its ammonium salt, 1-3 parts of 1,7-decanedioic acid and its ammonium salt, and 3-5 parts of amine of eicosadiene dicarboxylic acid (HS-04) by mass fraction, and the inorganic acid and its amine salt include 1-3 parts of boric acid by mass fraction. Through the mutual synergistic effect of the organic acid and its amine salt and the inorganic acid and its amine salt, the conductivity of the electrolyte can be improved, so that the electrolyte has the characteristics of high voltage resistance, high solubility, good high temperature and low temperature resistance, good stability and long service life.

[0038] Due to the low boiling point of water, the high vapor pressure, when the temperature exceeds 100 DEG C, it is easy to cause the capacitance air pressure is big and invalid, and water and aluminum foil is easy to appear hydration, resulting in aluminum foil lose original performance, when the temperature is higher, the higher the voltage, the greater the content of water, the more obvious the phenomenon of water and aluminum foil hydration, in order to adapt to the characteristics of high voltage large ripple aluminum electrolytic capacitor, the application gives up the water as a good solvent, and selects organic solvent, specifically: the organic solvent includes: ethylene glycol, glycerol, butanediol, diethylene glycol, benzyl alcohol, oligomeric ethylene glycol and r-butyl lactone at least one; Because the electrolyte is mostly organic acid with long carbon chain or branched chain and its salt, its solubility in a single organic solvent is small, and the effect obtained by different compatibility is not the same; therefore, preferably, the organic solvent includes 50-60 parts of ethylene glycol, 5-10 parts of benzyl alcohol, 5-10 parts of butanediol and 5-10 parts of polyethylene glycol 400 by mass fraction; Because the solubility of single ethylene glycol in dissolving the above electrolyte is small, when the polyhydroxy alcohol (such as glycerol and diethylene glycol) is increased, the solubility of the electrolyte is obviously increased, more preferably, the organic solvent includes 50-60 parts of ethylene glycol, 10-20 parts of glycerol and 5-10 parts of diethylene glycol by mass fraction, through the compounding of multiple organic solvents, the solubility of the electrolyte can be effectively improved, thereby improving the conductivity of the electrolyte and the life of the electrolyte.

[0039] Due to the reaction between the internal electrolyte and the aluminum foil under the action of current during the use of the capacitor, hydrogen is produced in the process, which cannot be utilized in the capacitor, and if not eliminated, it will produce hydrogen gas, which will seriously increase the pressure in the capacitor, cause the capacitor to drum bottom and even explode and fail, in order to eliminate hydrogen element, the application adopts to increase the hydrogen scavenger, the hydrogen scavenger includes: at least one of p-nitrobenzoic acid, ammonium p-nitrobenzoate, p-nitrobenzyl ether and p-nitrobenzyl alcohol; preferably, the hydrogen scavenger is p-nitrobenzyl ether; more preferably, the hydrogen scavenger is p-nitrobenzyl alcohol.

[0040] The high temperature stabilizer provided by the application includes: first stabilizer and second stabilizer; the first stabilizer includes: at least one of phosphoric acid, mannitol and citric acid; the second stabilizer includes: at least one of phosphorous acid, hypophosphorous acid and butyl phosphate; although there are many choices of high temperature stabilizer, the effect of single use is not good, and the effect obtained by different compatibility is not the same, preferably, the high temperature stabilizer includes: 1-5 parts of mannitol, 0.5-2 parts of citric acid and 0.5-2 parts of hypophosphorous acid by weight fraction; more preferably, the high temperature stabilizer includes: 0.5-2 parts of phosphoric acid, 1-5 parts of mannitol and 0.5-2 parts of citric acid by weight fraction.

[0041] In order to improve the voltage resistance of the electrolyte, the voltage resistance improver comprises: a first voltage resistance agent and a second voltage resistance agent, the first voltage resistance agent comprises at least one of polyvinyl alcohol, high polyethylene glycol, polyvinyl alcohol ester, nano silicon dioxide and polyethylene glycol ester; the second voltage resistance agent comprises nano silicon dioxide, and the conductivity can also be effectively improved by using nano silicon dioxide.

[0042] Since the preparation method of the electrolyte is also very critical, it has a great influence on the stability and ultralow temperature performance of the electrolyte, in order to ensure that the electrolyte for electrolytic capacitor has the effect of the application, the application also provides a preparation method of the electrolyte, which specifically comprises the following steps:

[0043] S1, heating and mixing the organic solvent and the inorganic acid to 160 DEG C, maintaining for 120 min, to obtain a first mixed solution;

[0044] S2, reducing the temperature of the first mixed solution to 140 DEG C, adding organic acid and its amine salt, inorganic acid amine salt, first stabilizer and first voltage resistance agent, maintaining for 60 min, to obtain a second mixed solution;

[0045] S3, reducing the temperature of the second mixed solution to 105 DEG C, adding second stabilizer and hydrogen removal agent, maintaining for 30 min, to obtain a third mixed solution;

[0046] S4, reducing the temperature of the third mixed solution to 95 DEG C, adding second voltage resistance agent, maintaining for 20 min, and then cooling to obtain the electrolyte for electrolytic capacitor.

[0047] Firstly, since the electrolyte, solvent, hydrogen removal agent, high temperature stabilizer and voltage resistance improver are basically organic substances, the organic reaction has the following characteristics: one, when the organic chemical reaction is carried out, it is often accompanied by side reactions, that is, in a plurality of substances, due to the complexity of chemical bonds and functional groups, in addition to the required positive reaction, there may also be condensation reaction, esterification reaction, amidation reaction, etherification reaction, decomposition reaction and addition reaction, etc. The occurrence of these side reactions will affect the progress of the positive reaction, and then affect the performance parameters of the electrolyte (mainly including the difference of conductivity, PH value, flash voltage, etc.), and directly affect the service life of the capacitor, therefore, setting appropriate component compatibility and reaction conditions has extremely important influence on the performance of the electrolyte; two, the condition control of organic chemical reaction is very strict, even if the reactants are the same, but under different reaction conditions (such as different temperature, time and solvent), the product may be completely different, the application controls the temperature and time of heating and cooling accurately, ensures high solubility and the occurrence of positive reaction, reduces side reactions and by-products, and effectively protects the various performances of the electrolyte to be applicable to high-voltage large-ripple aluminum electrolytic capacitor.

[0048] Secondly, since the high-temperature bearing capacity of the first stabilizer and the second stabilizer in the high-temperature stabilizer is different, the high-temperature bearing capacity of the first pressure-resistant agent and the second pressure-resistant agent in the pressure-resistant enhancer is also different, and they need to be added separately to prevent the high-temperature stabilizer from deteriorating due to excessively high temperature.

[0049] Finally, the preparation method of the electrolyte is relatively simple, and is suitable for mass production and use.

[0050] The technical solutions of the embodiments of the present application are described in detail below with reference to the drawings.

[0051] Embodiment one

[0052] The electrolyte for electrolytic capacitors provided by the present application comprises the following components in parts by mass: 3-5 parts of sebacic acid and its ammonium salt, 1-3 parts of dodecanedioic acid and its ammonium salt, 1-3 parts of 1,7-decanedioic acid and its ammonium salt, 3-5 parts of amine of eicosadiene dicarboxylic acid (HS-04), 1-3 parts of boric acid, 50-60 parts of ethylene glycol, 10-20 parts of glycerol, 5-10 parts of diethylene glycol, 0.5-2.5 parts of p-nitrobenzyl alcohol, 0.5-2 parts of phosphoric acid, 1-5 parts of mannitol, 0.5-2 parts of citric acid, 3-8 parts of polyvinyl alcohol, 3-8 parts of polyethylene glycol 2000, 3-8 parts of polyvinyl ester, 3-8 parts of polyethylene glycol ester, and 3-8 parts of nano silicon dioxide.

[0053] The preparation method of the electrolyte provided by the present application specifically comprises the following steps:

[0054] S1, heat and mix 50-60 parts of ethylene glycol, 10-20 parts of glycerol, 5-10 parts of diethylene glycol, and 1-3 parts of boric acid, heat to 160℃, and maintain for 120 min to obtain a first mixed solution;

[0055] S2, reduce the temperature of the first mixed solution to 140℃, add 3-5 parts of sebacic acid and its ammonium salt, 1-3 parts of dodecanedioic acid and its ammonium salt, 1-3 parts of 1,7-decanedioic acid and its ammonium salt, 3-5 parts of amine of eicosadiene dicarboxylic acid (HS-04), 0.5-2 parts of phosphoric acid, 1-5 parts of mannitol, 0.5-2 parts of citric acid, 3-8 parts of polyvinyl alcohol, 3-8 parts of polyethylene glycol 2000, 3-8 parts of polyvinyl ester, 3-8 parts of polyethylene glycol ester, and maintain for 60 min to obtain a second mixed solution;

[0056] S3, reduce the temperature of the second mixed solution to 105℃, add 0.5-2.5 parts of p-nitrobenzyl alcohol, and maintain for 30 min to obtain a third mixed solution;

[0057] S4, the temperature of the third mixed solution is reduced to 95℃, 3-8 parts of nano-silica is added, and after maintaining for 20 min, cooling is performed to obtain the electrolyte for electrolytic capacitor.

[0058] Example Two

[0059] The electrolyte for electrolytic capacitor of the present application comprises the following components in parts by mass: 3-5 parts of sebacic acid and its ammonium salt, 1-3 parts of azelaic acid and its ammonium salt, 1-3 parts of octadecene diacid and its ammonium salt, 3-5 parts of amine of 20-carbon diene dicarboxylic acid (HS-04), 1-3 parts of boric acid, 50-60 parts of ethylene glycol, 5-10 parts of diethylene glycol, 10-20 parts of butanediol, 0.5-2.5 parts of p-nitrobenzoic acid, 1-5 parts of mannitol, 0.5-2 parts of citric acid, 0.5-2 parts of phosphorous acid, 3-8 parts of polyvinyl alcohol, 3-8 parts of polyethylene glycol 2000, 3-8 parts of polyvinyl ester, 3-8 parts of polyethylene glycol ester, and 3-8 parts of nano-silica.

[0060] The preparation method of the electrolyte provided by the present application specifically comprises the following steps:

[0061] S1, 50-60 parts of ethylene glycol, 5-10 parts of diethylene glycol, 10-20 parts of butanediol, and 1-3 parts of boric acid are heated and mixed, heated to 160℃, and maintained for 120 min to obtain a first mixed solution;

[0062] S2, the temperature of the first mixed solution is reduced to 140℃, 3-5 parts of sebacic acid and its ammonium salt, 1-3 parts of azelaic acid and its ammonium salt, 1-3 parts of octadecene diacid and its ammonium salt, 3-5 parts of amine of 20-carbon diene dicarboxylic acid (HS-04), 1-5 parts of mannitol, 0.5-2 parts of citric acid, 3-8 parts of polyvinyl alcohol, 3-8 parts of polyethylene glycol 2000, 3-8 parts of polyvinyl ester, 3-8 parts of polyethylene glycol ester, and are maintained for 60 min to obtain a second mixed solution;

[0063] S3, the temperature of the second mixed solution is reduced to 105℃, 0.5-2.5 parts of p-nitrobenzoic acid and 0.5-2 parts of phosphorous acid are added, and maintained for 30 min to obtain a third mixed solution;

[0064] S4, the temperature of the third mixed solution is reduced to 95℃, 3-8 parts of nano-silica is added, and after maintaining for 20 min, cooling is performed to obtain the electrolyte for electrolytic capacitor.

[0065] Example Three

[0066] The electrolyte for electrolytic capacitor of the application comprises the following components in parts by mass: 1-3 parts of dodecanedioic acid and its ammonium salt, 3-5 parts of azelaic acid and its ammonium salt, 1-3 parts of pentaborate amine, 3-5 parts of amine icosene dicarboxylate (HS-04), 1-3 parts of boric acid, 50-60 parts of ethylene glycol, 5-10 parts of benzyl alcohol, 5-10 parts of butanediol, 5-10 parts of polyethylene glycol 400, 0.5-2.5 parts of p-nitroanisole, 1-5 parts of mannitol, 0.5-2 parts of citric acid, 0.5-2 parts of hypophosphorous acid, 3-8 parts of polyvinyl alcohol, 3-8 parts of polyethylene glycol 2000, 3-8 parts of polyvinyl alcohol ester, 3-8 parts of polyethylene glycol ester, and 3-8 parts of nano silicon dioxide.

[0067] The application provides a preparation method of the electrolyte, specifically comprising the following steps:

[0068] S1, heating and mixing 50-60 parts of ethylene glycol, 5-10 parts of benzyl alcohol, 5-10 parts of butanediol, 5-10 parts of polyethylene glycol 400 and 1-3 parts of boric acid, heating to 160℃ and maintaining for 120 min to obtain a first mixed solution;

[0069] S2, reducing the temperature of the first mixed solution to 140℃, adding 1-3 parts of dodecanedioic acid and its ammonium salt, 3-5 parts of azelaic acid and its ammonium salt, 1-3 parts of pentaborate amine, 3-5 parts of amine icosene dicarboxylate (HS-04), 1-5 parts of mannitol, 0.5-2 parts of citric acid, 3-8 parts of polyvinyl alcohol, 3-8 parts of polyethylene glycol 2000, 3-8 parts of polyvinyl alcohol ester, 3-8 parts of polyethylene glycol ester, and maintaining for 60 min to obtain a second mixed solution;

[0070] S3, reducing the temperature of the second mixed solution to 105℃, adding 0.5-2 parts of hypophosphorous acid and 0.5-2.5 parts of p-nitroanisole, and maintaining for 30 min to obtain a third mixed solution;

[0071] S4, reducing the temperature of the third mixed solution to 95℃, adding 3-8 parts of nano silicon dioxide, maintaining for 20 min, and cooling to obtain the electrolyte for electrolytic capacitor.

[0072] Example four

[0073] The electrolyte for electrolytic capacitor of the application comprises the following components in parts by mass: 1-3 parts of dodecanedioic acid and its ammonium salt, 1-3 parts of 1,7-decanedioic acid and its ammonium salt, 3-5 parts of ammonium 2-methylnonanedioate (HS-02), 3-5 parts of pentaborate amine, 1-3 parts of boric acid, 50-60 parts of ethylene glycol, 5-10 parts of benzyl alcohol, 5-10 parts of polyethylene glycol 400, 5-10 parts of r-butyrolactone, 0.5-2.5 parts of ammonium p-nitrobenzoate, 1-5 parts of mannitol, 0.5-2 parts of citric acid, 0.5-2 parts of butyl phosphate, 3-8 parts of polyvinyl alcohol, 3-8 parts of polyethylene glycol 2000, 3-8 parts of polyvinyl alcohol ester, 3-8 parts of polyethylene glycol ester, and 3-8 parts of nano silicon dioxide.

[0074] The application provides a preparation method of the electrolyte, specifically comprising the following steps:

[0075] S1, heating and mixing 5-10 parts of benzyl alcohol, 5-10 parts of polyethylene glycol 400, 5-10 parts of r-butyrolactone and 1-3 parts of boric acid, heating to 160℃ and maintaining for 120 min to obtain a first mixed solution;

[0076] S2, reducing the temperature of the first mixed solution to 140℃, adding 1-3 parts of dodecanedioic acid and its ammonium salt, 1-3 parts of 1,7-decanedioic acid and its ammonium salt, 3-5 parts of ammonium 2-methylnonanedioate (HS-02), 3-5 parts of boric acid amine, 1-5 parts of mannitol, 0.5-2 parts of citric acid, 3-8 parts of polyvinyl alcohol, 3-8 parts of polyethylene glycol 2000, 3-8 parts of polyvinyl alcohol ester and 3-8 parts of polyethylene glycol ester, and maintaining for 60 min to obtain a second mixed solution;

[0077] S3, reducing the temperature of the second mixed solution to 105℃, adding 0.5-2 parts of butyl phosphate and 0.5-2.5 parts of ammonium p-nitrobenzoate, and maintaining for 30 min to obtain a third mixed solution;

[0078] S4, reducing the temperature of the third mixed solution to 95℃, adding 3-8 parts of nano silicon dioxide, maintaining for 20 min, and cooling to obtain the electrolyte for electrolytic capacitor.

[0079] Comparative Example 1

[0080] The electrolytic solution for electrolytic capacitor of Comparative Example 1 comprises the following components in parts by mass: 3-5 parts of sebacic acid and its ammonium salt, 2-6 parts of dodecanedioic acid and its ammonium salt, 1-3 parts of 1,7-decanedioic acid and its ammonium salt, 3-5 parts of amine of eicosadiene dicarboxylic acid (HS-04), 50-60 parts of ethylene glycol, 10-20 parts of glycerol, 5-10 parts of diethylene glycol, 0.5-2.5 parts of p-nitrobenzyl alcohol, 0.5-2 parts of phosphoric acid, 1-5 parts of mannitol, 0.5-2 parts of citric acid, 3-8 parts of polyvinyl alcohol, 3-8 parts of polyethylene glycol 2000, 3-8 parts of polyvinyl ester, 3-8 parts of polyethylene glycol ester, and 3-8 parts of nano-silicon dioxide.

[0081] The preparation method of the electrolytic solution provided by Comparative Example 1 specifically comprises the following steps:

[0082] S1, heat and mix 50-60 parts of ethylene glycol, 10-20 parts of glycerol, and 5-10 parts of diethylene glycol, heat to 160℃, and maintain for 120 min to obtain a first mixed solution;

[0083] S2, reduce the temperature of the first mixed solution to 140℃, add 3-5 parts of sebacic acid and its ammonium salt, 2-6 parts of dodecanedioic acid and its ammonium salt, 1-3 parts of 1,7-decanedioic acid and its ammonium salt, 3-5 parts of amine of eicosadiene dicarboxylic acid (HS-04), 0.5-2 parts of phosphoric acid, 1-5 parts of mannitol, 0.5-2 parts of citric acid, 3-8 parts of polyvinyl alcohol, 3-8 parts of polyethylene glycol 2000, 3-8 parts of polyvinyl ester, 3-8 parts of polyethylene glycol ester, and maintain for 60 min to obtain a second mixed solution;

[0084] S3, reduce the temperature of the second mixed solution to 105℃, add 0.5-2.5 parts of p-nitrobenzyl alcohol, and maintain for 30 min to obtain a third mixed solution;

[0085] S4, reduce the temperature of the third mixed solution to 95℃, add 3-8 parts of nano-silicon dioxide, maintain for 20 min, and then cool to obtain the above-mentioned electrolytic solution for electrolytic capacitor.

[0086] Comparative Example 2

[0087] The electrolytic solution for aluminum electrolytic capacitor commonly sold on the market, such as the GBL electrolytic solution for aluminum electrolytic capacitor produced by Xinxin New Carbon Materials Changzhou Co., Ltd.

[0088] The composition of the electrolytic solution in the above-mentioned Examples 1 to 4 and Comparative Example 1 is shown in the following table, and each component is in parts by mass:

[0089]

[0090]

[0091] Test results

[0092] (1) Test on initial performance of electrolyte

[0093] The electrolyte for electrolytic capacitor in Example 1 to Example 4 and Comparative Example 1 and the electrolyte for electrolytic capacitor commonly sold on the market were tested in terms of conductivity, pH value and flashover voltage, and the specific results were as follows:

[0094]

[0095] As shown in the above table, the conductivity of the electrolyte provided in Example 1 to Example 3 was 2.0±0.3, 1.5±0.3 and 1.5±0.3 respectively; the conductivity of the electrolyte in Comparative Example 2 was 1.4±0.3. It can be seen that the conductivity of the electrolyte provided in the present application is greatly improved compared with the electrolyte commonly sold on the market, and in particular, the conductivity of the electrolyte provided in Example 1 is improved by 45%. It can be seen from Example 1 and Comparative Example 1 that compared with the case of only using organic acid and its amine salt as electrolyte, the conductivity can be greatly improved when the electrolyte in the present application simultaneously uses organic acid and its amine salt and inorganic acid and its amine salt. At the same time, since the conductivity and the conductivity of the electrolyte have a negative correlation with the voltage resistance, the higher the conductivity, the lower the voltage resistance, but the flashover voltage (equivalent to the voltage resistance) of the electrolyte in each example in the present application is also above 490V, which effectively improves the conductivity and effectively maintains the voltage resistance of the electrolyte, that is, the voltage resistance of the electrolyte does not decrease with the increase of the conductivity, which is suitable for high-voltage and large-ripple aluminum electrolytic capacitor.

[0096] (2) Test on high-temperature stability of electrolyte

[0097] The electrolyte for electrolytic capacitor in Example 1 to Example 4 and the electrolyte for electrolytic capacitor commonly sold on the market were stored at 125℃ for 1000 hours, and the changes of the parameters of each electrolyte were as follows:

[0098]

[0099] The conductivity change rate of the electrolyte in the above Table Comparative Example 2 decreased by 31.21%, the conductivity change rate of the electrolyte in Example 1 decreased by 6.83%, the conductivity change rate of the electrolyte in Example 2 decreased by 13.82%, the conductivity change rate of the electrolyte in Example 3 decreased by 6.63%, and the conductivity change rate of the electrolyte in Example 4 decreased by 9.63%. It can be seen that the decrease rate of the conductivity change rate of the electrolyte provided in Examples 1 to 4 is much lower than that of the electrolyte in Comparative Example 2, which indicates that the high-temperature stability of the electrolyte provided in Examples 1 to 4 is better. Among them, the electrolyte provided in Example 1 and Example 3 has a smaller change rate of conductivity under long-term load at 125°C, which indicates that the electrolyte in Example 1 and Example 3 has the best high-temperature stability. The compatibility and content of each component in the electrolyte make the electrolyte have the best high-temperature stability.

[0100] (3) Test of the service life of the electrolyte

[0101] The aluminum electrolytic capacitor was produced by using the same materials (except for the electrolyte) and the same production process, and the production specification and main material list are as follows:

[0102] Specification: 450V 1000μF, size 35*60, and the main materials of the capacitor are as follows:

[0103]

[0104]

[0105] The parameters of the aluminum electrolytic capacitor were measured under the same conditions, i.e. a constant temperature oven at 105°C, a ripple current of 4A per capacitor, and a voltage of 450V (the peak of the alternating voltage generated by the ripple current and the direct voltage, which does not exceed the rated voltage 450V). After 4000 hours of testing, the parameters were measured every 1000 hours, and the specific data are shown in the following table:

[0106]

[0107] As shown in the above table, after high pressure, high temperature, large ripple current, long time life test comparison and verification, the electrolyte for electrolytic capacitor provided in the first to fourth embodiments of the present application all reached the 2000 hour target requirement, but the electrolyte in Comparative Example 2 showed a small loss of capacitance at 2000 hours, and could not achieve a longer service life, indicating that the performance of the electrolyte in Comparative Example 2 was not stable, and the change rate of the electrolytic capacitor provided in the first embodiment of the present application was the smallest, followed by the electrolyte provided in the third embodiment, and after 4000 hours of ripple life, the results of each parameter were still good. Compared with the electrolyte in Comparative Example 2, the electrolyte provided in the present application can effectively improve the service life, and it still has high stability under the environment of high pressure, high temperature and large ripple current. The service life of the electrolyte provided in the fourth embodiment cannot reach 4000 hours, indicating that although the electrolyte provided in the present application has the same upper components and contents, the specific component combination and the content of each component have different effects on the performance of the electrolyte, indicating that each specific component needs appropriate combination and specific component content to achieve the effect.

[0108] It should be noted that during the ripple resistance test, the leakage current is stable and decreasing, and the capacity and loss angle measurement frequency are both 120 Hz, which will not be described in detail here.

[0109] In summary, according to the above test, the electrolyte for electrolytic capacitor in the first embodiment has the best performance in all aspects, the electrolyte for electrolytic capacitor in the third embodiment has the second best performance in all aspects, and the electrolyte for electrolytic capacitor in the fourth embodiment has relatively poor performance in all aspects compared with the electrolyte for electrolytic capacitor in the first to third embodiments, indicating that although the electrolyte provided in the present application has the same upper components and contents, the specific component combination and the content of each component have different effects on the performance of the electrolyte, indicating that each specific component needs appropriate combination and specific component content to achieve the effect.

[0110] Example Five

[0111] The present application also provides a high-voltage large-ripple aluminum electrolytic capacitor, which uses the above-mentioned electrolyte for electrolytic capacitor.

[0112] The electrolyte for electrolytic capacitor and the preparation method thereof are described in detail in the above embodiments, which will not be described here.

[0113] In the embodiments of the present application, the high-voltage large-ripple aluminum electrolytic capacitor adopting the electrolyte for electrolytic capacitor of the present application has the capacitor performance obviously improved, the loss angle energy decreased by more than 2 percentage points, the ESR of the capacitor decreased by more than 30%, and the ripple current bearing capacity reached more than 1.5 times of other aluminum electrolytic capacitors, that is, the aluminum electrolytic capacitor adopting the electrolyte for electrolytic capacitor provided by the present application, in the case of the same power and the same ripple current requirement of the power supply, as long as the capacity is two-thirds of the original or even smaller, the power supply space is saved, thereby the volume of the power supply can be effectively reduced, and the process of the power supply to the small volume direction is accelerated; at the same time, the aluminum electrolytic capacitor adopting the electrolyte for electrolytic capacitor provided by the present application is used on the filter power supply, which can also effectively reduce the power loss and improve the precision of the power supply, so that the current output is more stable, and the service life is longer.

[0114] As to the device in the above-mentioned embodiments, the specific manner in which each module performs operations has been described in detail in the embodiments related to the method, and will not be described in detail here.

[0115] The scheme of the present application has been described in detail above with reference to the drawings. In the above-mentioned embodiments, the description of each embodiment is focused on different aspects, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments. Those skilled in the art should also know that the actions and modules involved in the specification are not necessarily required by the present application. In addition, it can be understood that the steps in the method embodiments of the present application can be adjusted, combined and reduced in sequence according to actual needs, and the modules in the device embodiments of the present application can be combined, divided and reduced according to actual needs.

[0116] The flowcharts and block diagrams in the drawings show the possible implementation architecture, function and operation of the system and method according to the embodiments of the present application. In this regard, each block in the flowchart or block diagram can represent a module, a program segment or a part of code, which contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks can also occur in different order from that marked in the drawings. For example, two consecutive blocks can actually be executed substantially in parallel, and sometimes they can be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system that performs the specified function or operation, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0117] Having described various embodiments of the application, it is to be understood that the above description is meant not to limit and not to encompass all of the possible embodiments. Many modifications and variations of this application can be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. It is intended that the scope of the application be defined by the scope of the patent and by the claims as allowed by the patent office, which can include adaptations based on the description, equivalents, and / or substitutions of elements individually or collectively to the entire disclosure.

Claims

1. An electrolyte for electrolytic capacitors, characterized in that: The composition by mass includes the following components: 8-16 parts of organic acids and their amine salts, 1-8 parts of inorganic acids and their amine salts, 65-90 parts of organic solvents, 0.5-2.5 parts of hydrogen scavenger, 2-9 parts of high-temperature stabilizer, and 15-40 parts of voltage resistance enhancer. The organic acids and their amine salts include: 3-5 parts of sebacic acid and its ammonium salt, 1-3 parts of dodecadic acid and its ammonium salt, 1-3 parts of 1,7-sebacic acid and its ammonium salt, and 3-5 parts of eicosadiene dicarboxylic acid amine. The inorganic acid and its amine salt include 1-3 parts of boric acid; The organic solvent includes 50-60 parts of ethylene glycol, 10-20 parts of glycerol and 5-10 parts of diethylene glycol; The hydrogen scavenger comprises 0.5-2.5 parts of p-nitrobenzyl alcohol; The high-temperature stabilizer comprises 0.5-2 parts of phosphoric acid, 1-5 parts of mannitol, and 0.5-2 parts of citric acid; The voltage resistance booster comprises 3-8 parts of polyvinyl alcohol, 3-8 parts of polyethylene glycol 2000, 3-8 parts of polyvinyl alcohol ester, 3-8 parts of polyethylene glycol ester, and 3-8 parts of nano-silica.

2. A method for preparing an electrolyte, characterized in that: Specifically, the following steps are included: 50-60 parts of ethylene glycol, 10-20 parts of glycerol, 5-10 parts of diethylene glycol and 1-3 parts of boric acid are heated and mixed to 160°C and maintained for 120 minutes to obtain the first mixed solution. The temperature of the first mixed solution was lowered to 140°C, and 3-5 parts of sebacic acid and its ammonium salt, 1-3 parts of dodecadic acid and its ammonium salt, 1-3 parts of 1,7-sebacic acid and its ammonium salt, 3-5 parts of eicosadiene dicarboxylic acid amine, 0.5-2 parts of phosphoric acid, 1-5 parts of mannitol, 0.5-2 parts of citric acid, 3-8 parts of polyvinyl alcohol, 3-8 parts of polyethylene glycol 2000, 3-8 parts of polyvinyl alcohol ester, and 3-8 parts of polyethylene glycol ester were added. The mixture was maintained for 60 minutes to obtain the second mixed solution. The temperature of the second mixed solution was lowered to 105°C, and 0.5-2.5 parts of p-nitrobenzyl alcohol were added. The mixture was maintained for 30 minutes to obtain the third mixed solution. The temperature of the third mixed solution was lowered to 95°C, 3-8 parts of nano-silica were added, and the mixture was maintained for 20 minutes before cooling to obtain the electrolyte for the electrolytic capacitor.

3. A high-voltage, high-ripple aluminum electrolytic capacitor, characterized in that: The capacitor uses the electrolyte for electrolytic capacitors as described in claim 1.

Images