CN118899552B

CN118899552B - Lead-acid battery electrolyte and application thereof

Info

Publication number: CN118899552B
Application number: CN202411388903.1A
Authority: CN
Inventors: 刘玉; 黄嘉林; 王卫东; 郭志刚; 卢晓华; 孔鹤鹏; 闫鑫金
Original assignee: Tianneng Battery Group Co Ltd
Current assignee: Tianneng Battery Group Co Ltd
Priority date: 2024-10-08
Filing date: 2024-10-08
Publication date: 2025-03-28
Anticipated expiration: 2044-10-08
Also published as: CN118899552A; WO2026076964A1

Abstract

The invention discloses an electrolyte for a lead storage battery and application thereof, and belongs to the technical field of lead storage battery production. According to the invention, the electrolyte is improved, the surface tension of the electrolyte is changed by adding the surfactant, so that the layering phenomenon of the electrolyte can be slowed down from the source, and meanwhile, the introduced surfactant can capture lead ions in the electrolyte to form a stable complex, thereby avoiding the formation of lead dendrites and reducing the risk of short circuit.

Description

Electrolyte for lead storage battery and application thereof

Technical Field

The invention belongs to the technical field of lead storage battery production, and particularly relates to electrolyte for a lead storage battery and application of the electrolyte.

Background

Valve-regulated sealed lead acid batteries (VRLA batteries) are widely used as an efficient and reliable energy storage device in power systems, UPS power supplies, railway systems, communication equipment and various emergency equipment. Its core advantages are its maintenance-free nature and long service life, which are largely attributable to the AGM (Absorbent Glass Mat) separator used. The AGM separator is used as a key component of the VRLA battery, has excellent acid erosion resistance, high void ratio and good insulating property, can effectively fix electrolyte and provides an oxyhydrogen composite channel in the charge and discharge process, thereby realizing the maintenance-free function of the battery and improving the overall performance of the battery.

However, while AGM separators perform well in VRLA batteries, their presence of short plates increasingly appears in certain applications, such as stationary applications and deep cycle power cells, significantly limiting the battery's cycle life. The main problems are focused on two major aspects of electrolyte layering and lead dendrite shorting.

1. Electrolyte delamination problem

Electrolyte stratification is a common problem in VRLA batteries, especially during long-term operation or extreme conditions. Due to the influence of the surface tension of the electrolyte and the characteristics of the separator, the phenomenon of uneven density of the electrolyte in the height direction occurs in the battery, and the phenomenon is shown that the sulfuric acid content at the bottom is significantly higher than that at the middle and upper parts. The layering phenomenon causes the sulfation of the bottom of the positive electrode and the negative electrode to be aggravated, the positive electrode structure is damaged, the softening phenomenon occurs, the sulfation of the negative electrode is more irreversible, the positive electrode and the negative electrode are finally disabled, and the battery capacity is remarkably attenuated.

Aiming at the problem of electrolyte layering, the solution is mainly attempted to be solved by adjusting the proportion of coarse cotton and fine cotton in the formula of the separator. Increasing the proportion of fine cotton can enhance the delamination resistance of the separator, but at the same time can reduce the wet state pressure, which has a negative effect on the battery life. Therefore, manufacturers need to balance carefully in the formulation design to increase delamination resistance as much as possible while maintaining a certain wet pressure. However, for thin separators of limited design, particularly at thicknesses below 0.50mm (100 kPa), electrolyte delamination problems remain severe, severely limiting the cycle life of the cell.

2. Short circuit problem of lead dendrite

Lead dendrite shorting is another major challenge faced by VRLA batteries during long term use. In the charge-discharge cycle, lead ions are continuously dissolved and precipitated, and finally, lead dendrites are accumulated on the fibers inside the separator. As the number of cycles increases, lead dendrites may penetrate the separator, resulting in micro-shorting between the positive and negative electrodes, which in turn results in a voltage drop and a reduction in battery discharge time. For stationary use batteries, the risk of lead dendrite shorting is higher due to prolonged resting conditions. And the thin separator is more likely to generate micro-short circuits during cycling due to relatively low structural strength, further accelerating the decay of battery capacity.

To solve the problem of short-circuiting of lead dendrites, various strategies have been adopted in the industry, including controlling the discharge rate of the battery, adding additives to stabilize the electrolyte, and limiting dendrite growth using external circuitry. However, these measures have limited effectiveness in practical applications, particularly for battery systems that operate for long periods of time and for high-intensity cycles, there is still a need to further explore more effective solutions.

Disclosure of Invention

Based on the defects in the prior art, the invention provides the electrolyte for the lead storage battery and the application thereof, the electrolyte is improved, and the problems of electrolyte layering and lead dendrite short circuit are solved by adding the surfactant.

The specific technical scheme of the invention is as follows:

The electrolyte for the lead storage battery comprises sulfuric acid and an additive, wherein the additive comprises 0.5-1.0% of inorganic salt and 0.05-0.20% of surfactant by mass of sulfuric acid;

wherein the inorganic salt is anhydrous sodium sulfate, and the surfactant is at least one of sodium dodecyl sulfate and sodium dodecyl benzene sulfonate.

Preferably, the mass fraction of the sulfuric acid is 31% -35%. The sulfuric acid used in the invention is diluted by concentrated sulfuric acid, the density of the concentrated sulfuric acid is 1.83g/cm ³, and the mass fraction is 98.3%.

Preferably, when the surfactant is sodium dodecyl sulfate and sodium dodecyl benzene sulfonate, the mass ratio of sodium dodecyl sulfate to the surfactant is not less than 50%.

On one hand, the surfactant adopts sodium dodecyl sulfate and sodium dodecyl benzene sulfonate, the effect of the mixed addition of the two is better than that of single use, on the other hand, after the surfactant is added in the formation process, foaming phenomenon exists, foam flows out, the addition amount of the surfactant is lost, the result of circuit short circuit is seriously caused, and experiments show that the most critical control of the proportion of the sodium dodecyl sulfate and the sodium dodecyl benzene sulfonate in the surfactant ensures that the proportion of the sodium dodecyl sulfate is more and the foaming is controllable. Finally, the amount of the inorganic salt to be added can be controlled, and the voltage to be formed can be controlled, so that the foaming phenomenon can be controlled to a certain extent.

The invention also provides application of the electrolyte for the lead storage battery in preparation of the lead storage battery.

Specifically, when the thickness h of the separator of the lead storage battery is less than 0.5mm, the addition amount of the surfactant is not less than 0.1%, and when the thickness h of the separator of the lead storage battery is not less than 0.5mm, the addition amount of the surfactant is not more than 0.18%.

Further, the plate surface height of the polar plate is marked as H, the distance between the positive polar plate and the negative polar plate is marked as L,

The resistance to delamination is different from H and L, distinguishing the cells, from different cell performance requirements and from different design parameters.

H is the polar plate height, and H also determines the capacity of battery, and H also has decided layering phenomenon, and the higher can layering more easily, L is positive negative polar plate's interval, and obviously L's distance just has decided the thickness of baffle, and the thinner the baffle, the easier dendrite short circuit of baffle, the less base material of baffle also is more easily layering. In this case, a thin cotton separator with good delamination resistance is usually selected, but a thinner separator is selected, so that the thin cotton cannot solve the above problems and is expensive. In contrast, the thicker the separator, the more base material, and in contrast, a coarse cotton separator may be used, but the coarse cotton separator has the natural disadvantage of layering, and also needs to be considered to reduce layering from the electrolyte formulation.

In the battery design, H and L are actually two important parameters, and in general, the battery will not be too short and the capacity is difficult to reach, so that H will maintain a certain value, that is, the ratio of H/L, from this perspective, the larger L is, the smaller the ratio of H/L is, the wider the distance between positive and negative is, the less dendrite short-circuiting is easy, the acid is easy to add, the temperature is easy to control, and the specific energy of the battery is low.

The smaller L is, the narrower the distance between positive and negative is, the larger the H/L value is, the easier dendrite short circuit is, and the temperature control is not good. The idea of the invention is therefore to solve the problem of separator delamination by means of an electrolyte.

When the thickness H of a separator of the lead storage battery is less than 0.5mm, when the H/L is more than 120, the addition amount of the surfactant is not less than 0.15 percent, and when the H/L is less than or equal to 120, the addition amount of the surfactant is less than 0.15 percent;

If the thickness of the separator is lower than 0.5mm, the separator substrate is thin, as mentioned above, the delamination-resistant separator cannot solve the problem, H/L >120 is very small, namely L is very small, a 0.45mm separator is selected, in experiments, the addition amount is not lower than 0.15% for delamination resistance and short circuit resistance, the effect is relatively good, H/L is less than or equal to 120, L is slightly larger, the thickness of the separator is slightly larger, and from the aspects of experimental effect and cost, the addition amount of the surfactant is lower than 0.15% and can be optimal;

when the thickness H of the separator of the lead storage battery is more than or equal to 0.5mm, the addition amount of the surfactant is 0.15% -0.18% when the H/L is more than or equal to 120, and the addition amount of the surfactant is 0.05% -0.10% when the H/L is less than or equal to 120.

If the thickness of the separator is greater than 0.5mm, the separator substrate is barely suitable, and the delamination-resistant separator can solve a part of problems, but the price of the separator is much higher, and in order to control the design cost, the separator with the thickness value usually adopts a separator mainly made of coarse cotton, so that the natural delamination-resistant effect is poor.

Therefore, the H/L is 120, namely L is very small, for example, the thickness of the partition board is 0.52mm, in experiments, the addition amount is 0.15% -0.18% for resisting layering and short-circuiting, the effect is good, the H/L is less than or equal to 120, the L is bigger, the thickness of the substrate of the partition board can be completely layered, but from the angles of experimental effect and cost, the addition amount of the surfactant is 0.05% -0.10%, so that the problem can be solved;

specifically, the preparation method of the electrolyte for the lead storage battery comprises the following steps:

sulfuric acid used in preparation;

and adding the surfactant according to the thickness of a separator of the lead storage battery, the height of the plate surface of the polar plate and the distance between the positive polar plate and the negative polar plate, adding the surfactant into the prepared sulfuric acid, and then adding the inorganic salt to obtain the electrolyte for the lead storage battery.

The method specifically comprises the following steps:

1) Preparing dilute sulfuric acid according to the mass fraction of the dilute sulfuric acid required by batch formation, wherein the amount of the dilute sulfuric acid is A (kilogram), calculating and determining the amount B (kilogram) of the concentrated sulfuric acid, calculating the amount C (kilogram) of pure water required by the prepared dilute sulfuric acid, weighing 0.8C (kilogram) of pure water, slowly adding the weighed concentrated sulfuric acid B (kilogram), and reducing the temperature for later use;

2) Weighing 0.2C (kilogram) of pure water, determining the adding proportion according to the design parameters (H and H/L) of the batch of batteries, weighing the surfactant according to the mass A (kilogram) and dissolving the surfactant in the pure water, wherein the surfactant is independently added with sodium dodecyl sulfate or sodium dodecyl benzene sulfonate or a mixed sample of sodium dodecyl sulfate and sodium dodecyl benzene sulfonate, and when the two are mixed, the mass proportion of the mixed sample occupied by the sodium dodecyl sulfate is not less than 50 percent, and stirring until the surfactant is completely dissolved in the pure water for later use;

3) Adding the surfactant solution prepared in the step (2) into the dilute sulfuric acid prepared in the step (1);

4) Finally, adding anhydrous sodium sulfate with a certain proportion according to the mass A (kilogram);

5) And cooling the prepared electrolyte to the temperature ranging from 0 ℃ to 5 ℃ for standby.

And setting the acid adding volume of an acid adding machine according to the addition amount of the battery batch to complete acid adding.

After the acid addition is completed, cooling is carried out in a water cooling tank (the water temperature is lower than 20 ℃) for not less than 25 minutes.

After the completion of cooling, the mixture flows into the formation tank, and the charge formation is started.

Because the surfactant is easy to foam, in the preparation of the lead storage battery, the formation current is controlled in the formation stage, the formation voltage is not more than 16.5V, the process is prevented from foaming, and the addition amount of the surfactant is ensured.

The invention has the beneficial effects that:

According to the invention, the electrolyte is improved, the surface tension of the electrolyte is changed by adding the surfactant, so that the layering phenomenon of the electrolyte can be slowed down from the source, and meanwhile, the introduced surfactant can capture lead ions in the electrolyte to form a stable complex, thereby avoiding the formation of lead dendrites and reducing the risk of short circuit.

Drawings

Fig. 1 is a lead dendrite in the AGM separator of the No. 9 battery of example 3.

Fig. 2 is the lead dendrites in the AGM separator of the No. 14 cell of example 3.

Fig. 3 is the lead dendrites in the AGM separator of the No. 1 cell of example 4.

Fig. 4 is a lead dendrite in the AGM separator of the No. 7 cell of example 4.

Fig. 5 is the lead dendrites in the AGM separator of the No. 4 cell of example 5.

Fig. 6 is a lead dendrite in the AGM separator of the No. 7 cell of example 5.

Detailed Description

In the electrolyte configuration and the battery use, the sulfuric acid concentration is less than 31%, the electrolyte concentration is too low, the initial capacity is lower, the standard requirement is difficult to reach, the open-circuit voltage of the battery is over 35%, the service life of the battery is seriously influenced, the normal range is 31% -35%, and the invention takes the concentration of 32% as an example:

The concentration of the prepared electrolyte is required to be 32%, the weight is 100kg, the concentrated sulfuric acid with the mass fraction of 51% is used as a sulfuric acid mother solution, 62.75kg of mother acid is weighed, and the calculated pure water is required to be:

100kg-62.75kg=37.25kg;

pure water was split into two parts, one part being 29.80kg, i.e. 37.25kg x 0.8=29.80 kg;

the weight of the rest parts is 37.25kg-29.80 kg=7.45 kg;

Slowly pouring 62.75kg of sulfuric acid mother liquor into 29.80kg of pure water, uniformly stirring, and cooling at normal temperature for standby.

According to different battery designs, different formulas are selected, 100kg of additive (surfactant) is weighed, the additive amount is 0.05% -0.20%, the additive is added into 7.45kg of pure water, and the mixture is stirred uniformly until all the additive is completely dissolved, and then the mixture is poured into dilute sulfuric acid which is cooled to normal temperature.

And (3) weighing anhydrous sodium sulfate (inorganic salt) with the addition amount of 0.5-1.0% by calculating 100kg, adding the anhydrous sodium sulfate into dilute sulfuric acid, uniformly stirring, and completing the preparation of electrolyte.

And (3) placing the electrolyte in a low-temperature box, and cooling to the temperature ranging from 0 ℃ to 5 ℃ for later use.

Example 1

According to the above configuration method, different electrolyte formulations are respectively designed, the additive is one or two of sodium dodecyl sulfate or sodium dodecyl benzene sulfonate, the inorganic salt additive is anhydrous sodium sulfate, the voltage can reach about 16.5V in the general formation process, the voltage can be controlled to be not more than 16.5V, if the electrolyte foams and a large amount of foam flows out, the electrolyte formulation is not preferable, as shown in the following table 1.

TABLE 1

Scheme numbering	Anhydrous sodium sulfate	Sodium dodecyl sulfate	Sodium dodecyl benzene sulfonate	Whether or not to use
					1	0.40%	0.04%	/	Whether or not
2	0.40%	0.05%	/	Whether or not
					3	0.40%	0.15%	/	Whether or not
4	0.40%	0.18%	/	Whether or not
					5	0.40%	0.20%	/	Whether or not
6	0.40%	0.25%	/	Whether or not
					7	0.40%	/	0.04%	Whether or not
8	0.40%	/	0.05%	Whether or not
					9	0.40%	/	0.15%	Whether or not
10	0.40%	/	0.18%	Whether or not
					11	0.40%	/	0.20%	Whether or not
12	0.40%	/	0.25%	Whether or not
					13	0.50%	0.04%	/	Is that
14	0.50%	0.05%	/	Is that
					15	0.50%	0.15%	/	Is that
16	0.50%	0.18%	/	Is that
					17	0.50%	0.20%	/	Is that
18	0.50%	0.25%	/	Whether or not
					19	0.50%	/	0.04%	Is that
20	0.50%	/	0.05%	Is that
					21	0.50%	/	0.15%	Is that
22	0.50%	/	0.18%	Is that
					23	0.50%	/	0.20%	Is that
24	0.50%	/	0.25%	Whether or not
					25	1.00%	0.04%	/	Is that
26	1.00%	0.05%	/	Is that
					27	1.00%	0.15%	/	Is that
28	1.00%	0.18%	/	Is that
					29	1.00%	0.20%	/	Is that
30	1.00%	0.25%	/	Whether or not
					31	1.00%	/	0.04%	Is that
32	1.00%	/	0.05%	Is that
					33	1.00%	/	0.15%	Is that
34	1.00%	/	0.18%	Is that
					35	1.00%	/	0.20%	Is that
36	1.00%	/	0.25%	Whether or not
					37	1.20%	0.04%	/	Whether or not
38	1.20%	0.05%	/	Whether or not
					39	1.20%	0.15%	/	Whether or not
40	1.20%	0.18%	/	Whether or not
					41	1.20%	0.20%	/	Whether or not
42	1.20%	0.25%	/	Whether or not
					43	1.20%	/	0.04%	Whether or not
44	1.20%	/	0.05%	Whether or not
					45	1.20%	/	0.15%	Whether or not
46	1.20%	/	0.18%	Whether or not
					47	1.20%	/	0.20%	Whether or not
48	1.20%	/	0.25%	Whether or not
					49	0.50%	0.05%	0.05%	Is that
50	0.50%	0.06%	0.04%	Is that
					51	0.50%	0.04%	0.06%	Is that
52	1.00%	0.05%	0.05%	Is that
					53	1.00%	0.06%	0.04%	Is that
54	1.00%	0.04%	0.06%	Is that
					55	0.50%	0.075%	0.075%	Is that
56	0.50%	0.09%	0.06%	Is that
					57	0.50%	0.06%	0.09%	Is that
58	1.00%	0.075%	0.075%	Is that
					59	1.00%	0.09%	0.06%	Is that
60	1.00%	0.06%	0.09%	Is that
					61	0.50%	0.10%	0.10%	Is that
62	0.50%	0.12%	0.08%	Is that
					63	0.50%	0.08%	0.12%	Is that
64	1.00%	0.10%	0.10%	Is that
					65	1.00%	0.12%	0.08%	Is that
66	1.00%	0.08%	0.12%	Is that
					67	1.20%	0.125%	0.125%	Whether or not
68	1.20%	0.15%	0.10%	Whether or not
					69	1.20%	0.10%	0.15%	Whether or not
70	1.20%	0.125%	0.125%	Whether or not
					71	1.20%	0.15%	0.10%	Whether or not
72	1.20%	0.10%	0.15%	Whether or not

From the usable cases in Table 1, when the addition amount of anhydrous sodium sulfate was less than 0.50% or more than 1.0%, foaming was easy regardless of whether sodium dodecyl sulfate or sodium dodecyl benzene sulfonate was added alone or in a mixture.

The addition amount of anhydrous sodium sulfate is controlled within the range of 0.5% -1.0%, and the addition amount of sodium dodecyl sulfate or sodium dodecyl benzene sulfonate is independently added or mixed and added, wherein the addition amount cannot exceed 0.20%.

Example 2

A type battery is selected as an experimental battery, the height of a polar plate is 120mm, the distance between the positive polar plate and the negative polar plate is 0.885mm, and the thickness of a selected partition plate is 0.48mm (100 kPa).

The electrolyte formulation available in example 1 was selected, and experiments were performed, in which battery dissection was performed in 0 cycles (i.e., initial state), 100 cycles, 300 cycles, and end-of-life, the dissection required was that the rest time was not more than 10 minutes after full charge, the separator was cut into 3 parts in the height direction after dissection, in equal proportions, the separator was divided into upper, middle, and lower parts, acid extrusion, filtration, and chemical titration were performed separately, the sulfuric acid mass fraction of the electrolyte was tested, the layering condition of the electrolyte was reacted by the upper, middle, and lower extreme values, and at the same time, the separator in the end-of-life state was selected, SEM characterization was performed after washing and drying, and the size of lead sulfate particles was measured, with the larger grain size, representing a higher probability of short circuit.

The same batch of semi-finished batteries is selected as a comparison sample, and only sodium sulfate is added into the electrolyte.

TABLE 2

From the results shown in Table 2, the addition amount of the surfactant was not less than 0.15%, and the effect of adding sodium dodecyl sulfate and sodium dodecyl benzene sulfonate by mixing was better than that of adding them alone, and when adding them by mixing, the effect of adding sodium dodecyl sulfate by mass ratio exceeding 50% was better.

The addition amount is continuously increased to 0.20%, the effect is better, but the manufacturing cost is increased.

Example 3

The battery B is selected as an experimental battery, the battery A and the battery B are the same type of shell, different capacities are designed, the height direction of polar plates is different, the height of the polar plates of the battery B is 100mm, the distance between the positive polar plate and the negative polar plate is 0.885mm, and the thickness of the selected partition plates is 0.48mm (100 kPa).

The electrolyte formulation available in example 1 was selected, and experiments were performed, in which battery dissection was performed in 0 cycles (i.e., initial state), 100 cycles, 300 cycles, and end-of-life, respectively, the dissection required was that the rest time was not more than 10 minutes after full charge, after dissection, the separator was cut into 3 parts in the height direction in equal proportions, and divided into upper, middle, and lower parts, acid extrusion, filtration, and chemical titration were performed separately, the sulfuric acid mass fraction of the electrolyte was tested, the layering situation of the electrolyte was reacted by the upper, middle, and lower extreme values, and at the same time, the separator in the end-of-life state was selected, SEM characterization was performed after washing and drying, and the size of lead sulfate particles was measured, with the larger grain size, representing a higher probability of short circuit.

TABLE 3 Table 3

The lead dendrite patterns in the AGM separators of the numbered 9 and 14 batteries are shown in fig. 1 and 2, respectively. As can be seen from FIG. 1, the data in Table 3 shows that the grain size is about 3 μm, which is significantly smaller than that of the comparative sample (in this example, cell numbers 1 and 2), and thus significantly improved. In this example, the number 3 to 10 batteries are obtained by adding sodium dodecyl sulfate or sodium dodecyl benzene sulfonate alone, the size of the lead dendrite is gradually reduced with the increase of the surfactant, and after the addition amount reaches 0.15%, the addition amount is continuously increased, and the grain size also reaches about 3 μm. As can be seen from the results of fig. 2 and table 3, the number of the batteries is 11 to 20, the mixed surfactant is selected and added, and from the number of the batteries 11 to 12, it can be seen that when the total amount of the mixed surfactant added is not more than 0.10%, the grain size is larger than 12 μm, and from the number of the batteries 13 to 14, and when the total amount of the mixed surfactant added is 0.10%, the grain size becomes smaller, and as the adding proportion of sodium dodecyl sulfate in the mixed surfactant increases, the grain size becomes smaller gradually.

From the results, the addition amount of the surfactant is in the range of 0.10% -0.15%, the effect is ideal, the effect is obviously better than that of a comparison sample, and when the addition amount reaches 0.15%, the effect is not further improved when the addition amount is continuously increased.

In addition, the mixing and adding effects of the sodium dodecyl sulfate and the sodium dodecyl benzene sulfonate are better than those of the single addition, when the sodium dodecyl sulfate is mixed and added, the effect is better when the mass ratio of the sodium dodecyl sulfate exceeds 50%.

Example 4

C batteries are selected as experimental batteries, A, B, C are the same type of shell, different capacities are designed, the heights of polar plates of the C batteries are 120mm as well as the positive polar plate and the negative polar plate of the C batteries are 0.980mm as with the A batteries, and the thickness of a selected partition plate is 0.52mm (100 kPa).

The method comprises the steps of selecting an available electrolyte formula, performing experiments, performing battery dissection in 0 cycles (namely an initial state), 100 cycles, 300 cycles and service life termination, wherein the dissection requirement is that after full charge, standing time is not more than 10 minutes, cutting the separator into 3 parts along the height direction after dissection, dividing the separator into upper parts, middle parts and lower parts in equal proportion, performing acid squeezing, filtering and chemical titration independently, testing the sulfuric acid mass fraction of the electrolyte, reacting the layering condition of the electrolyte through the upper-middle-lower extreme values, selecting the separator in the service life termination state, performing SEM characterization after washing and drying, measuring the size of lead sulfate particles, wherein the larger the grain size is, and the probability of representing short circuit is higher.

TABLE 4 Table 4

The lead dendrite patterns in the AGM separators of the No.1 and No. 7 batteries are shown in FIG. 3 and FIG. 4, respectively, the No.1 battery is a comparative sample, only inorganic salt is added, and it can be seen that the size of crystal grains exceeds 14 μm, the battery is easy to be short-circuited, and the No. 7 battery, by independently adding sodium dodecyl benzene sulfonate, the proportion of inorganic salt is increased, and the size of crystal grains is obviously reduced. From the results shown in Table 4, the addition amount of the surfactant is in the range of 0.15% -0.18%, the effect is ideal, the effect is obviously better than that of the comparative sample, and when the addition amount reaches 0.18%, the effect is not further improved by continuously increasing the addition amount.

Example 5

The D battery is selected as an experimental battery, A, B, C, D is the same type of shell, different capacities are designed, the height of the polar plate of the D battery is 100mm, the distance between the positive polar plate and the negative polar plate is 0.980mm, and the thickness of the selected baffle plate is 0.52mm (100 kPa) as the B battery.

TABLE 5

The lead dendrite patterns in the AGM separators of the No.4 and No. 7 batteries are shown in FIG. 5 and FIG. 6, respectively, the No.4 battery shows that the grain size is reduced to 4 μm by adding 0.05% sodium dodecyl sulfate based on the inorganic salt additive, the No. 1 battery is compared, the grain size growth is obviously slowed down, and the No. 7 battery shows that the grain size growth is obviously slowed down by adding 0.04% sodium dodecyl benzene sulfonate based on the inorganic salt additive, the No. 2 battery is compared, the grain size is reduced to 7 μm. From the results shown in Table 5, the addition amount of the surfactant is in the range of 0.05% -0.10%, the effect is ideal, the effect is obviously better than that of the comparative sample, and when the addition amount reaches 0.10%, the effect is not further improved by continuously increasing the addition amount.

Claims

1. The application of the electrolyte for the lead storage battery in preparing the lead storage battery comprises, by mass, 0.5% -1.0% of inorganic salt and 0.04% -0.20% of surfactant, wherein the electrolyte comprises sulfuric acid and an additive;

wherein the inorganic salt is anhydrous sodium sulfate, and the surfactant is at least one of sodium dodecyl sulfate and sodium dodecyl benzene sulfonate;

When the thickness h of the separator of the lead storage battery is less than 0.5mm, the addition amount of the surfactant is not less than 0.1%, and when the thickness h of the separator of the lead storage battery is not less than 0.5mm, the addition amount of the surfactant is not more than 0.18%.

2. The method according to claim 1, wherein the plate height is defined as H and the distance between the positive and negative plates is defined as L,

3. The use according to claim 2, characterized in that the method for preparing the electrolyte for lead accumulators comprises the following steps:

sulfuric acid used in preparation;

4. Use according to claim 1, characterized in that the voltage formed during the preparation of the lead-acid battery does not exceed 16.5V.

5. The use according to claim 1, wherein the mass fraction of sulfuric acid is 31% -35%.

6. Use according to claim 1, wherein when the surfactant is sodium dodecyl sulfate and sodium dodecyl benzene sulfonate, the proportion of sodium dodecyl sulfate to the surfactant is not less than 50% by mass.