Lead-sodium storage battery electrolyte and preparation method thereof

Abstract

The invention discloses a lead-sodium storage battery electrolyte in the technical field of storage batteries. The lead-sodium storage battery electrolyte comprises the following materials in parts by weight: 0.2-0.6 part of silicon dioxide, 30-50 parts of 98% anhydrous concentrated sulfuric acid, 2-4 parts of a sodium compound, 0.05-0.15 part of stannous mono-sulphate, 0.5-0.7 part of phosphoric acid, 1-2 parts of vanillin and 60-100 parts of deionized water. By modifying and improving the electrolyte, the influence of low temperature on the electrolyte is improved, and the low-temperature performance of the battery is facilitated, so that the advantages that the low-temperature resistance of the storage battery is good, and the service life of the storage battery is prolonged are effectively realized.

Description

Technical Field

[0001] The present invention relates to the technical field of storage batteries, and particularly relates to a lead-sodium storage battery. Background Art

[0002] The electrolyte of a lead-acid storage battery uses sulfuric acid as an electrolyte, and is mostly prepared with H 2 SO 4 , deionized water, and additives required for the electrolyte. The electrolyte is the third electrode of the lead-acid storage battery and also belongs to the active substance, which participates in the process of electric energy generation and accumulation. As the main material of the electrolyte, the H 2 SO 4 solution, its freezing point temperature will change with the change of the H 2 SO 4 concentration. For example, when the solution concentration increases from 0 °C (H 2 O) to contain 36% of H 2 SO 4 , the solidification temperature of the H 2 SO 4 solution drops from 0 °C (the freezing point of H 2 O) to -60 °C, and then as the solution concentration increases to 60%, the solidification temperature increases to -28 °C. During the discharge of the lead-acid storage battery, the concentration of H 2 SO 4 will become lower and lower. Therefore, the freezing point of H 2 SO 4 will depend on the state of charge of the battery, and the state of charge during the discharge of the storage battery will definitely become lower and lower. Therefore, the performance of the storage battery will deteriorate when used in a low-temperature environment, and its discharge capacity, charge acceptance ability, etc. will all be affected by low temperature. Therefore, a lead-sodium storage battery electrolyte and its preparation method are needed to solve the above problems. Summary of the Invention

[0003] Aiming at the deficiencies existing in the prior art, the present invention provides a lead-sodium storage battery electrolyte, which can effectively improve the low-temperature resistance performance and service life of the storage battery.

[0004] The purpose of the present invention is achieved as follows: A lead-sodium storage battery electrolyte includes the following materials in parts by weight: Silicon dioxide content is 0.2 - 0.6 parts, 98% anhydrous concentrated sulfuric acid is 30 - 50 parts, sodium compound is 2 - 4 parts, stannous sulfate is 0.05 - 0.15 parts, phosphoric acid is 0.5 - 0.7 parts, vanillin is 1 - 2 parts, and deionized water is 60 - 100 parts.

[0005] Further, the sodium compound is one or more of sodium stannous citrate, sodium stannate, sodium tetraborate, sodium sulfate, sodium silicate, sodium sulfide, sodium polyacrylate, sodium tripolyphosphate, sodium dimercaptosuccinate, sodium dodecylbenzenesulfonate, sodium perfluoroalkylsulfonate, sodium polyaspartate, and disodium nitrilotriacetate.

[0006] A method for preparing an electrolyte for a lead - sodium battery, comprising the following steps: S1. Add deionized water in proportion to the acid - mixing tank. Under continuous stirring, slowly add 98% anhydrous concentrated sulfuric acid. After the addition is complete, wait for the solution temperature to drop to room temperature. S2. Mix and modify the sodium compound, stannous sulfate, phosphoric acid, and vanillin in proportion to obtain mixture A. S3. Add mixture A to deionized water, heat and stir. After heating to the set temperature, stop heating, continue to stir evenly, and wait for the solution to cool to room temperature to obtain mixed solution B. S4. Add deionized water to the colloid disperser, then add fumed silica, and perform high - speed dispersion to form a uniform colloidal solution C. S5. Slowly add mixed solution B and colloidal solution C in proportion to the sulfuric acid solution prepared in S1, and stir to obtain the electrolyte.

[0007] Further, in S2, the grinding and modification speed is not less than 200 rpm, and the time is not less than 0.5 h.

[0008] Further, in S3, the temperature is raised to 48 - 52 °C.

[0009] Further, in S4, the high - speed dispersion time is 1 - 3 h.

[0010] Further, in S5, the stirring speed is not less than 1500 rpm, and the time is not less than 20 min.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: By using a mixture added with sodium, the present invention can reduce the viscosity of the electrolyte, enhance the ion migration efficiency, thereby reducing the increase in internal resistance in a low-temperature environment, and improving the discharge capacity and charge acceptance ability of the battery at low temperature; A mixture A is prepared by mixing and modifying a sodium compound, stannous sulfate, phosphoric acid, and vanillin. It is a composite additive with a smaller particle structure; and then it is heated and stirred in deionized water. After heating to a set temperature, heating is stopped, and stirring is continued until uniform. After the solution is cooled to room temperature, a mixed solution B is prepared. The substances in the mixed solution B are more dispersed, improving the uniformity after adding sulfuric acid; The freezing point of the colloidal solution C is lower than that of the sulfuric acid electrolyte, which can improve certain low-temperature performance. At the same time, it can effectively prevent the electrolyte from stratifying, ensure that the electrolyte density of the upper and lower layers of the battery is consistent, and avoid the problem of shortened battery life caused by concentration difference in traditional lead-acid batteries. With the synergistic effect of the mixture B and the colloidal solution C, the low-temperature cycle stability can be further improved. More preferably, by adding a sodium compound, the performance of the electrolyte can be improved, the charge balance efficiency inside the battery can be enhanced, and the ion transport path can be optimized, thereby stabilizing the voltage and increasing the overall capacity. By using the electrolyte and manufacturing method of the present invention to modify the electrolyte, the advantages of good low-temperature performance of the storage battery and extended service life of the storage battery are achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0013] Figure 1 It is a schematic diagram of the discharge of the embodiments and comparative examples of the present invention applied to a storage battery in a low-temperature state.

[0014] Figure 2 It is a schematic diagram of the discharge of the embodiments and comparative examples of the present invention applied to a storage battery in a normal-temperature state.

[0015] Figure 3 It is a cyclic life curve diagram of the embodiments and comparative examples of the present invention applied to a storage battery. DETAILED DESCRIPTION OF THE INVENTION

[0016] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0017] Example 1 An electrolyte for a lead - sodium battery and its preparation method. The electrolyte comprises 0.2 parts of silicon dioxide, 30 parts of 98% anhydrous concentrated sulfuric acid, 2 parts of sodium compound, 0.05 parts of stannous sulfate, 0.5 parts of phosphoric acid, 1 part of vanillin, and 60 parts of deionized water.

[0018] The sodium compounds are 0.05 parts of sodium stannous citrate, 1 part of sodium tetraborate, 0.5 parts of sodium sulfate, 0.1 parts of sodium polyacrylate, 0.1 parts of sodium tripolyphosphate, 0.1 parts of sodium dodecylbenzenesulfonate, 0.1 parts of sodium polyaspartate, and 0.05 parts of disodium nitrilotriacetate.

[0019] The specific preparation steps of the electrolyte are as follows: S1. Add 38 parts of deionized water into the acid - mixing tank. Under the condition of continuous stirring, slowly add 30 parts of 98% concentrated sulfuric acid. After the addition is completed, wait for the solution temperature to drop to room temperature. S2. According to the proportion, mix and modify 2 parts of sodium compound, 0.05 parts of stannous sulfate, 0.5 parts of phosphoric acid, and 1 part of vanillin at a rotation speed of 200 rpm for 1.5 h to obtain mixture A. S3. Add mixture A into 20 parts of deionized water, heat and stir. Stop heating after the temperature rises to 48 °C, continue to stir evenly, and wait for the solution to cool to room temperature to obtain mixed solution B. S4. Add 2 parts of deionized water into the colloid disperser, then add 0.2 parts of fumed silica, and carry out high - speed dispersion for 1 h to form a uniform colloidal solution C. S5. Slowly add mixed solution B and colloidal solution C into the sulfuric acid solution prepared in S1 and stir. The stirring speed is 1500 rpm and the time is 30 min to obtain the electrolyte.

[0020] Example 2 An electrolyte for a lead - sodium battery and its preparation method. The electrolyte comprises 0.4 parts of silicon dioxide, 40 parts of 98% anhydrous concentrated sulfuric acid, 3 parts of sodium compound, 0.1 parts of stannous sulfate, 0.6 parts of phosphoric acid, 1.5 parts of vanillin, and 80 parts of deionized water.

[0021] The sodium compounds are 0.1 parts of sodium stannous citrate, 1.5 parts of sodium tetraborate, 1 part of sodium sulfate, 0.05 parts of sodium silicate, 0.15 parts of sodium polyacrylate, 0.15 parts of sodium polyaspartate, and 0.05 parts of disodium nitrilotriacetate.

[0022] The specific preparation steps of the electrolyte are as follows: S1. Add 46 parts of deionized water into the acid - mixing tank. Under the condition of continuous stirring, slowly add 40 parts of 98% concentrated sulfuric acid. After the addition is completed, wait for the solution temperature to drop to room temperature. S2. Mix and modify 3 parts of sodium compound, 0.1 part of stannous sulfate, 0.6 part of phosphoric acid, and 1.5 parts of vanillin in proportion at a rotation speed of 250 rpm for 1 hour to obtain mixture A. S3. Add mixture A to 30 parts of deionized water, heat and stir. Stop heating after the temperature rises to 50 °C, continue to stir evenly, and wait for the solution to cool to room temperature to obtain mixed liquid B. S4. Add 4 parts of deionized water to a colloid disperser, then add 0.4 part of fumed silica, and perform high-speed dispersion for 2 hours to form a uniform colloidal solution C. S5. Slowly add mixed liquid B and colloidal solution C to the sulfuric acid solution prepared in S1 and stir at a stirring speed of 2000 rpm for 25 minutes to obtain the electrolyte.

[0023] Example 3 An electrolyte for a lead-sodium storage battery and its preparation method. The electrolyte includes 0.6 part of silicon dioxide, 50 parts of 98% anhydrous concentrated sulfuric acid, 4 parts of sodium compound, 0.15 part of stannous sulfate, 0.7 part of phosphoric acid, 2 parts of vanillin, and 100 parts of deionized water.

[0024] The sodium compound is 0.1 part of sodium stannous citrate, 0.1 part of sodium stannate, 2 parts of sodium tetraborate, 1.5 parts of sodium sulfate, 0.1 part of sodium silicate, 0.1 part of sodium polyaspartate, and 0.1 part of disodium nitrilotriacetate.

[0025] The specific preparation steps of the electrolyte are as follows: S1. Add 54 parts of deionized water to the acid mixing tank. Under continuous stirring, slowly add 50 parts of 98% concentrated sulfuric acid. After the addition is complete, wait for the solution temperature to drop to room temperature. S2. Mix and modify 4 parts of sodium compound, 0.15 part of stannous sulfate, 0.7 part of phosphoric acid, and 2 parts of vanillin in proportion at a rotation speed of 300 rpm for 0.5 hour to obtain mixture A. S3. Add mixture A to 40 parts of deionized water, heat and stir. Stop heating after the temperature rises to 52 °C, continue to stir evenly, and wait for the solution to cool to room temperature to obtain mixed liquid B. S4. Add 6 parts of deionized water to a colloid disperser, then add 0.6 part of fumed silica, and perform high-speed dispersion for 3 hours to form a uniform colloidal solution C. S5. Slowly add mixed liquid B and colloidal solution C to the sulfuric acid solution prepared in S1 and stir at a stirring speed of 2500 rpm for 20 minutes to obtain the electrolyte.

[0026] Comparative Example The electrolyte comprises 40 parts of 98% anhydrous concentrated sulfuric acid, 0.1 part of stannous sulfate, 0.6 part of phosphoric acid, 80 parts of deionized water, 1.5 parts of sodium tetraborate, and 1 part of sodium sulfate.

[0027] The specific preparation steps of the electrolyte are as follows: S1. Add 80 parts of deionized water to the acid mixing tank. While continuously stirring, slowly add 40 parts of 98% concentrated sulfuric acid. After the addition is completed, wait for the solution temperature to drop to room temperature. S2. Slowly add 0.1 part of stannous sulfate, 0.6 part of phosphoric acid, 1.5 parts of sodium tetraborate, and 1 part of sodium sulfate to the sulfuric acid solution prepared in S1, and stir to obtain the electrolyte.

[0028] The above electrolyte Examples 1, 2, 3 and the comparative example are poured into batteries of the same model, and then formed into storage batteries. The following test methods are adopted: 10-hour rate capacity test: For the fully charged storage battery within 1 h to 24 h after the charging ends, discharge with a current of I 10 (A). The temperature around the storage battery is kept between 20 and 25 °C. During the discharge time, the change in the current value should not be greater than 1%. When the single-cell voltage of the storage battery reaches 1.80 V, stop discharging and record the discharge time, and calculate the discharge capacity.

[0029] -40 °C low-temperature capacity test: Place the fully charged storage battery in an environment of -40 °C ± 2 °C and let it stand for 20 h. Discharge the storage battery with a current of I 10 (A). During the discharge process, the temperature around the storage battery is kept between -40 °C ± 2 °C, and the change in the current value should not be greater than 1%. When the single-cell voltage of the storage battery reaches 1.80 V, stop discharging and record the discharge time, and calculate the discharge capacity.

[0030] Cycle life test: The temperature around the storage battery is kept between 20 and 25 °C. a) Discharge with a current of I 10 (A) until the single-cell voltage of the storage battery reaches 1.80 V; b) Limit the voltage to 2.35 V / cell and charge with 2.5I10 (A) for 12 h; c) Repeat steps a) and b). (When the discharge time in step a is less than 8 hours, the life test ends) As can be seen from the above, as Figures 1-3 shown, by comparing the solutions of Examples 1 to 3 with the comparative example, when the 10-hour rate capacity is close, using the electrolyte and manufacturing method of the present invention can obtain better low-temperature performance and cycle life. The components of the present invention are simple, the production cost is relatively low, the storage battery prepared has good low-temperature resistance performance and cycle life, and has a wide application range.

[0031] The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A lead-sodium battery electrolyte, characterized in that: Including the following materials by weight: 0.2-0.6 parts of silicon dioxide, 30-50 parts of 98% anhydrous concentrated sulfuric acid, 2-4 parts of sodium compounds, 0.05-0.15 parts of stannous sulfate, 0.5-0.7 parts of phosphoric acid, 1-2 parts of vanillin, and 60-100 parts of deionized water.

2. A lead-sodium battery electrolyte according to claim 1, characterized in that: The sodium compound is one or more of sodium citrate stannate, sodium stannate, sodium tetraborate, sodium sulfate, sodium silicate, sodium sulfide, sodium polyacrylate, sodium tripolyphosphate, sodium dimercaptosuccinate, sodium dodecylbenzene sulfonate, sodium polyfluoroalkyl sulfonate, sodium polyaspartate, and disodium nitrilotriacetate.

3. A method for preparing a lead-sodium battery electrolyte as claimed in claim 1 or 2, characterized in that: The following steps are involved: S1. Add deionized water in proportion to the acid preparation tank, and slowly add 98% anhydrous concentrated sulfuric acid under constant stirring. After the addition is completed, wait for the solution temperature to drop to room temperature; S2. Mix and modify the sodium compound, stannous sulfate, phosphoric acid and vanillin according to the proportion to obtain a mixture A; S3, adding mixture A to deionized water, heating and stirring, heating to the set temperature, stopping heating, continuing to stir evenly, and waiting for the solution to cool to room temperature to obtain a mixed solution B; S4, adding deionized water to the colloidal disperser, and then adding fumed silica, and dispersing at high speed to form a uniform colloidal solution C; S5. Slowly add the mixed solution B and the colloidal solution C in proportion to the sulfuric acid solution prepared in S1 and stir to obtain an electrolyte.

4. The method for preparing a lead-sodium battery electrolyte according to claim 3, characterized in that: The grinding and modification speed in S2 is not less than 200 rpm, and the time is not less than 0.5 h.

5. The method for preparing a lead-sodium battery electrolyte according to claim 3 or 4, characterized in that: In S3, the temperature is raised to 48~52°C.

6. The method for preparing a lead-sodium battery electrolyte according to claim 3 or 4, characterized in that: S4 medium-high speed dispersion for 1 to 3 hours.

7. The method for preparing a lead-sodium battery electrolyte according to claim 3 or 4, characterized in that: In S5, the stirring speed is not less than 1500 rpm and the time is not less than 20 min.

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