阅读说明：本技术 一种铅酸蓄电池离子液体电解液及其制备方法 (Lead-acid storage battery ionic liquid electrolyte and preparation method thereof ) 是由 罗江水 尤金海 易滢婷 于 2021-09-18 设计创作，主要内容包括：本发明涉及铅酸蓄电池技术领域,具体公开了一种铅酸蓄电池离子液体电解液及其制备方法,包括稀硫酸溶液和离子液体,所述稀硫酸溶液的密度为1.300g/cm～(3)～1.400g/cm～(3),稀硫酸溶液的含量为5～30％,离子液体的含量为70～95％。本发明将离子液体稀释硫酸溶液作为铅蓄电池的新型电解液。经过稀释的硫酸能避免电解液对电池零部件的过度腐蚀。此外由于提高了电化学窗口,降低了水含量,且离子液体较强的亲水性,能避免充电过程中水的电解及蒸发造成的水分缺失,提高了铅酸蓄电池的使用寿命和安全性。(The invention relates to the technical field of lead-acid storage batteries, and particularly discloses an ionic liquid electrolyte for a lead-acid storage battery and a preparation method thereof, wherein the ionic liquid electrolyte comprises a dilute sulfuric acid solution and an ionic liquid, and the density of the dilute sulfuric acid solution is 1.300g/cm 3 ～1.400g/cm 3 The content of the dilute sulfuric acid solution is 5-30%, and the content of the ionic liquid is 70-95%. The invention uses the ionic liquid diluted sulfuric acid solution as the novel electrolyte of the lead storage battery. The diluted sulfuric acid can avoid excessive corrosion of the electrolyte to the battery parts. In addition, because the electrochemical window is improved, the water content is reduced, and the ionic liquid has stronger hydrophilicity, the water loss caused by the electrolysis and evaporation of water in the charging process can be avoided, and the service life and the safety of the lead-acid storage battery are improved.)

1. The ionic liquid electrolyte for the lead-acid storage battery is characterized in that: comprises a dilute sulphuric acid solution and ionic liquid, wherein the density of the dilute sulphuric acid solution is 1.300g/cm³～1.400g/cm³The content of the dilute sulfuric acid solution is 5-30%, and the content of the ionic liquid is 70-95%.

2. The ionic liquid electrolyte of the lead-acid storage battery as claimed in claim 1, wherein: the ionic liquid is one or a mixture of non-proton type ionic liquid, proton type ionic liquid or zwitter ionic liquid.

3. The ionic liquid electrolyte of the lead-acid storage battery as claimed in claim 2, wherein: the cation structure of the aprotic ionic liquid is one of the following structural formulas:

wherein R1, R2, R3, R4 are alkyl (containing perfluoroalkyl); non-proton type ionThe anion of the liquid is HSO₄ ^-H of⁺From HSO₄ ^-Provided is a method.

4. The ionic liquid electrolyte of the lead-acid storage battery as claimed in claim 2, wherein: the cation structure of the proton type ionic liquid is one of the following structural formulas:

wherein R1, R2, R3, R4 and R5 are alkyl or H atoms, and the anion in the proton type ionic liquid is HSO₄ ^-Or SO₄ ^2-，H⁺From cations or anions.

5. The ionic liquid electrolyte of the lead-acid storage battery as claimed in claim 2, wherein: the cation structure of the zwitterionic liquid is one of the following structural formulas:

wherein R1, R2 are alkyl or H atoms; the anion in the zwitterionic liquid is HSO₄ ^-Or SO₄ ^2-，H⁺From cations or anions.

6. The method for preparing the ionic liquid electrolyte of the lead-acid storage battery according to any one of claims 1 to 5, characterized by comprising the following steps: and adding dilute sulfuric acid into the ionic liquid, and stirring and mixing uniformly to obtain the ionic liquid electrolyte.

7. The ionic liquid electrolyte of a lead-acid storage battery according to claim 6, wherein: the lead-acid storage battery is prepared by adopting the ionic liquid electrolyte.

8. The ionic liquid electrolyte of a lead-acid storage battery according to claim 7, wherein: the diaphragm of the lead-acid storage battery is a high polymer material diaphragm or a glass fiber diaphragm.

9. The ionic liquid electrolyte of the lead-acid storage battery as claimed in claim 1, wherein: the electrolyte also comprises imidazole additives.

Technical Field

The invention relates to the technical field of lead-acid storage batteries, in particular to an ionic liquid electrolyte for a lead-acid storage battery and a preparation method thereof.

Background

Since the 21 st century, the rapid development of global economy has sharply increased the demand for fossil energy supplies, and the non-renewable and increasingly scarce situation of fossil energy and the environmental pollution caused by the fossil energy have led to the development of new energy storage technologies. Lead-acid batteries have significant advantages of abundant raw materials, mature manufacturing process, low price of finished products, safe and reliable performance and the like, and are widely applied in various fields of communication, traffic, electric power and the like.

At present, lead-acid batteries still occupy the leading position in the industry all the time in the fields of automobile starting, electric mopeds, communication base stations, industrial forklifts and the like. However, the lead-acid battery still has the problems of short cycle life, easy falling of active substances and the like, and the development and the use of the size of the lead-acid battery are influenced. Secondly, the negative pole of the lead-acid battery is subjected to hydrogen evolution and self-discharge in the later charging period to cause the dehydration of the electrolyte, the polarization potential and the specific surface area of the negative pole are reduced, the internal resistance and the ion diffusion resistance of the battery are increased, the oxygen evolution of the battery is severe, and the failure of the battery is accelerated. In addition, lead-acid batteries also have problems with the falling off of the negative active material and the early capacity fade of the negative electrode caused by corrosion of the busbar and the negative tab. Lead-acid batteries also have high requirements for low and high temperature performance and cycle life as starting batteries. The above disadvantages and requirements present new challenges for lead acid batteries.

In order to solve the problems, researchers carry out a great deal of beneficial research work and provide corresponding solutions, which mainly comprise: (1) negative electrode additives such as carbon materials, conductive polymers, inorganic and metal oxide materials, and the like; (2) electrolyte additives such as sulfates, inorganic additives, fumed silica, organic additives, and the like; (3) novel lead-acid batteries, such as wound batteries, super batteries, bipolar batteries, and the like.

The electrolyte is used as the core composition of the lead-acid storage battery and has very important function. The electrolyte of the traditional lead-acid storage battery is easy to decompose and evaporate water in the charging process, so that the water needs to be continuously supplemented in the using process of the battery, and the components of the battery are corroded by the electrolyte, so that the application of the electrolyte is limited; although the conventional valve-regulated lead-acid battery can reduce water loss, it is still necessary to replenish a certain amount of water in a long-term use, and it is urgent to develop a novel electrolyte that can prevent corrosion of battery parts and does not require water replenishment.

Disclosure of Invention

The invention provides an ionic liquid electrolyte of a lead-acid storage battery and a preparation method thereof, which are used for solving the problems that the existing lead-acid storage battery needs to be continuously supplemented with water in the use process, and the battery parts are corroded by the electrolyte.

In order to achieve the purpose, the technical scheme of the invention is as follows:

the lead-acid storage battery ionic liquid electrolyte comprises a dilute sulfuric acid solution and ionic liquid, wherein the density of the dilute sulfuric acid solution is 1.300g/cm³～1.400g/cm³The content of the dilute sulfuric acid solution is 5-30%, and the content of the ionic liquid is 70-95%.

The technical principle and the effect of the technical scheme are as follows:

1. the novel electrolyte of the lead-acid storage battery has the advantages that (1) the combination of anions and cations in the ionic liquid can provide H⁺And SO₄ ^2-Make the whole electrolyte inside H⁺And SO₄ ^2-Is so high that its rate characteristics exceed those of conventional lead-acid batteries; (2) the conductivity is high, a small amount of water is dissolved in the ionic liquid, so that the decomposition voltage of the water is greatly improved, the electrolysis of the water cannot occur in the actual operation process of the lead-acid battery, and the water consumption is avoided; (3) the vapor pressure is very small, the material is non-volatile and non-flammable, the use temperature range is wide, the material can work below 0 ℃ and even above 100 ℃, the material can be recycled, the environmental pollution is avoided, and the safety is high; (4) the composition of different ionic liquids can be adjusted through the design of anions and cations.

Further, the ionic liquid is one or a mixture of an aprotic ionic liquid, a protic ionic liquid or a zwitterionic liquid.

Further, the cation structure of the aprotic ionic liquid is one of the following structural formulas:

wherein R1, R2, R3, R4, R5 are alkyl; the anion of the aprotic ionic liquid is HSO₄ ^-H of⁺From HSO₄ ^-Provided is a method.

Further, the cation structure of the proton type ionic liquid is one of the following structural formulas:

wherein R1, R2, R3, R4 and R5 are alkyl or H, and the anion in the proton type ionic liquid is HSO₄ ^-Or SO₄ ^2-，H⁺From cations and anions.

Further, the cation structure of the zwitterionic liquid is one of the following structural formulas:

wherein R1, R2 are alkyl or H; the anion in the zwitterionic liquid is HSO₄ ^-Or SO₄ ^2-，H⁺From cations or anions.

The preparation method of the ionic liquid electrolyte of the lead-acid storage battery is disclosed, and the ionic liquid electrolyte is obtained by adding dilute sulfuric acid into the ionic liquid and uniformly stirring and mixing.

Has the advantages that: the preparation method is simple and feasible, can be prepared at normal temperature, is easy for large-scale production, can effectively solve the problems of water decomposition, corrosion of battery parts and the like in the traditional lead-acid storage battery, and greatly improves the practicability and safety of the traditional lead-acid storage battery.

Further, the lead-acid storage battery is prepared by adopting the ionic liquid electrolyte.

Furthermore, the diaphragm of the lead-acid storage battery is a high polymer material diaphragm or a glass fiber diaphragm.

Further, the electrolyte also comprises an imidazole additive.

Has the advantages that: the viscosity of the electrolyte can be reduced by a trace amount of the imidazole additive.

Detailed Description

The following is further detailed by way of specific embodiments:

example 1:

an ionic liquid electrolyte for lead-acid storage batteries comprises a dilute sulfuric acid solution and an ionic liquid, in this embodiment 1, the dilute sulfuric acid solutionThe density of the solution was 1.300g/cm³The content (weight) of the dilute sulfuric acid solution is 5%, the content of the ionic liquid is 95%, and in addition, in order to reduce the viscosity of the electrolyte, a small amount of benzimidazole is added, and the ionic liquid in this embodiment is specifically: n-ethylpyridine hydrogen sulfate.

The preparation method comprises the following steps: adding 50g of ionic liquid with the density of 1.300g/cm into 950g of ionic liquid³Then fully and evenly stirring the dilute sulfuric acid to obtain the electrolyte.

Examples 2 to 20:

the difference from the embodiment 1 is that the ionic liquid and the dilute sulfuric acid in the embodiments 2 to 20 have different proportions, as shown in the following table 1:

wherein, the example 17 is the combination of two ionic liquids of 1, 3-dimethyl imidazole bisulfate and N-ethyl piperidine bisulfate, and the volume fraction of each ionic liquid is 50 percent;

example 18 is a combination of 1, 3-dimethylimidazole hydrogen sulfate and 2-sulfonic acid ethylamine hydrogen sulfate, each at a volume fraction of 50%;

example 19 is a combination of N-ethylpiperidine hydrogen sulfate and 2-sulfonic acid ethylamine hydrogen sulfate, each in a 50% volume fraction;

example 20 includes three ionic liquids: the volume fraction of the 1, 3-dimethyl imidazole bisulfate is 40 percent, the N-ethyl piperidine bisulfate is 40 percent, and the 2-sulfonic acid ethylamine bisulfate is 20 percent.

Table 1 shows the composition of examples 1 to 20 (in the table, "- -" means "does not contain")

Comparative example 1:

the difference from example 1 is that the density of the dilute sulfuric acid in comparative example 1 is 1.20g/cm³。

Comparative example 2:

the difference from example 1 is that the density of the dilute sulfuric acid in comparative example 2 is 1.40g/cm³。

Comparative example 3:

the difference from example 1 is that the content of dilute sulfuric acid in comparative example 3 is 2%, i.e. the content of ionic liquid is 98%.

Comparative example 4:

the difference from example 1 is that the content of dilute sulfuric acid in comparative example 4 is 50%, i.e., the content of ionic liquid is 50%.

Experiment:

the electrolyte prepared in the examples 1 to 20 and the comparative examples 1 to 4 is used for forming a simple lead-acid storage battery, wherein the negative electrode material is Pb, and the positive electrode material is PbO₂。

The charge-discharge mechanism of the lead-acid storage battery is as follows:

during discharging:

and (3) cathode reaction: pb-2e^-+SO₄ ^2-＝PbSO₄

And (3) positive pole reaction: PbO₂+2e^-+4H⁺+SO₄ ^2-＝PbSO₄+2H₂O

And (3) total reaction: pb + PbO₂+4H⁺+2SO₄ ^2-＝2PbSO₄+2H₂O

Charging:

and (3) cathode reaction: PbSO₄+2e^-＝Pb+SO₄ ^2-

And (3) positive pole reaction: PbSO₄+2H₂O＝PbO₂+2e^-+4H⁺+SO₄ ^2-

And (3) total reaction: 2PbSO₄+2H₂O＝Pb+PbO₂+2e^-+4H⁺+SO₄ ^2-

In the invention, the decomposition voltage of water in the dilute sulfuric acid solution is 1.23V, and the decomposition voltage of water in the ionic liquid is higher than 3V, so the decomposition voltages of the examples 1-20 exceed 3V, and the higher the decomposition voltage of water is, the less hydrolysis is generated in the actual operation process of the lead-acid storage battery, and the less water consumption is generated in the electrolyte.

The foregoing is merely an example of the present invention and common general knowledge of the known specific materials and characteristics thereof has not been described herein in any greater extent. It should be noted that, for those skilled in the art, without departing from the present invention, several changes and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.