WO2020034486A1

WO2020034486A1 - Long-life lead storage battery and preparation method therefor

Info

Publication number: WO2020034486A1
Application number: PCT/CN2018/117833
Authority: WO
Inventors: 郭志刚; 李桂发; 邓成智; 张峰博; 刘玉
Original assignee: 天能电池集团有限公司
Priority date: 2018-08-16
Filing date: 2018-11-28
Publication date: 2020-02-20
Also published as: CN109273716B; CN109273716A

Abstract

A long-life lead storage battery and a preparation method therefor, belonging to the technical field of storage batteries. The method for preparing the lead storage battery comprises completing a lead paste for a positive electrode plate in two portions, wherein a first lead paste containing stannous sulfate, antimony trioxide and 3BS and a second lead paste containing 4BS are respectively prepared, then carrying out a sandwich-type paste coating operation, wherein firstly, the first lead paste is applied as an inner layer, and then, the second lead paste is applied as a surface layer, and curing same at a medium temperature to obtain a green positive electrode plate; and assembling the prepared green positive electrode plate, and then subjecting same to container formation, wherein the container formation involves initially charging same using a relatively high-current density to obtain the long-life lead storage battery. In the method, by using the sandwich-type paste coating, the surface layer of the green electrode plate has a high content of 4BS, thereby alleviating the rate of sulfation of the surface layer; furthermore, in conjunction with the high-current formation process, the content of α-PbO₂ of the surface layer is increased, thereby reducing the rate of softening of the surface layer of the electrode plate during the process of a battery cycle, so that the cycle life of the battery is prolonged.

Description

Long-life lead storage battery and preparation method thereof

Technical field

The invention relates to the technical field of storage batteries, in particular to a long-life lead storage battery and a preparation method thereof.

Background technique

In the production process of lead-acid batteries, as a key process of the battery process, the quality of the battery directly affects the performance of the battery, especially the battery life and the initial performance of the battery, and the initial performance of the battery and the battery life are directly related to the lead-acid battery Consumer demand.

With the continuous development of lead-acid battery technology, the preparation technology of lead paste, the key raw material for manufacturing lead-acid batteries, is also constantly updated. The life of power batteries is a key factor in the design of battery lead paste. After using lead-calcium-tin-aluminum alloy, the battery life is shortened. In order to increase the deep cycle life of the battery, Sb ₂ O ₃ is generally added to the positive lead paste. Or SnSO ₄ , the main purpose is to overcome the antimony-free effect and improve the cycle life of the battery.

In order to further improve the battery life, a common method is to form a certain content of 4BS through the high temperature / cured high temperature when the paste is mixed, so as to strengthen the skeleton of the positive electrode active material to improve the battery life. However, due to the existence of the above two additives, no matter which method is adopted, it is difficult to form a 4BS skeleton in the positive electrode active material, and the purpose of further improving the battery life cannot be achieved.

Patent document CN103762358A discloses a positive electrode lead paste for lead-acid batteries and a preparation method thereof. A 4BS seed is added to the positive electrode lead paste, and a high temperature and a paste process are used (and the paste temperature is maintained above 70 ° C for a long period of time). At 5min), it further promotes 4BS to play the role of seed, generate a large number of 4BS, and improve the cycle life of the battery.

Patent document CN106910872A discloses a method for preparing a positive electrode plate of a lead storage battery. The preparation of lead paste is completed in two parts. The first part is to mix lead powder with antimony trioxide and stannous sulfate, and control the reaction not more than 50 ° Temperature, to obtain the first lead paste with 3BS as the main component; the second part of the additive involved in the lead paste and the production of additives do not contain antimony trioxide and stannous sulfate, control the reaction temperature of 80-85 ℃, obtain the first component with 4BS as the main component Two lead pastes to overcome the influence of Sb ₂ O ₃ or SnSO ₄ on the formation of 4BS; finally, the first lead paste and the second lead paste are mixed under relatively low temperature conditions to obtain positive lead paste containing both antimony-free effects Tin sulphate and antimony trioxide have 3BS and 4BS at the same time, which not only improves the battery life, but also guarantees the initial capacity.

In the prior art, the lead paste is uniformly coated on the grid after the preparation is completed, and the battery is assembled after curing and the electrolyte is added to form a lead storage battery. The surface layer of the electrode plate directly contacts the electrolyte. The degree of sulfate is more serious than that of the inner layer. In addition, in the initial stage of battery formation, a small current is usually used to charge and discharge. The current is conducted from the grid to the lead paste. There is an inconsistency in the conversion of the active material between the inner and outer layers. During use, the surface layer of the active material softens, which in turn affects the battery life.

Summary of the Invention

The purpose of the present invention is to provide a method for preparing a long-life lead-acid battery, so as to solve the problem that the active material of the positive electrode plate is easy to soften and fall off in the prior art.

To achieve the above objective, the present invention adopts the following technical solutions:

A method for preparing a long-life lead storage battery. The lead storage battery includes a positive electrode plate. The lead paste raw materials of the positive electrode plate include lead powder, additives, water, and sulfuric acid. The additives include antimony trioxide, stannous sulfate, and The carbon fiber is characterized in that the preparation method includes the following steps:

(1) Except for antimony trioxide and stannous sulfate, the remaining additives are mixed into two parts, and antimony trioxide and stannous sulfate are added in the first part, and not added in the second part;

(2) After dry mixing part of the lead powder with the first part of the additive, add water to wet mixing, and finally add sulfuric acid to stir the reaction, and control the reaction temperature not to exceed 50 ° C to obtain the first lead paste; dry mix the remaining lead powder with the second part of the additive Then, add water and wet mix, and finally add sulfuric acid to stir the reaction, and control the reaction temperature to 80-85 ° C to obtain a second lead paste;

(3) firstly applying the first lead paste on the grid to form the inner layer of the electrode plate, and then applying the second lead paste to the surface of the inner layer of the electrode plate to obtain the electrode plate;

(4) curing at a temperature not exceeding 55 ° C to obtain a positive electrode plate;

(5) Assemble the battery, add electrolyte, and perform internalization. The initial 7-8h is charged with a current density of 7-10mA / cm ² , and then charged at a current density of 3-5mA / cm ^{2 for} 30-40h. At the end, the long-life lead-acid battery was produced.

In terms of mass percentage, the components of the lead paste of the positive electrode plate include: antimony trioxide 0.05-0.5%, stannous sulfate 0.05-0.5%, carbon fiber 0.07%, water 12%, sulfuric acid 4-6%, and the rest For lead powder.

In steps (1) and (2), the preparation of the lead paste is performed in two parts. In the first part, the lead powder is mixed with additives containing antimony trioxide and stannous sulfate, and the reaction temperature is controlled at 40-50 ° C. to obtain The first lead paste, the main composition of the first lead paste is a tribasic lead sulfate crystal phase (3BS); the second part of the lead paste and the production temperature are controlled at 80-85 ° C, and the main composition is a tetrabasic lead sulfate crystal phase. (4BS) The second lead paste, because the additives do not contain antimony trioxide and stannous sulfate, to overcome the defects of these two additives affecting the formation of 4BS.

The first lead paste and the second lead paste are respectively coated on the grid, and the obtained positive electrode lead paste contains both stannous sulfate and stannous trioxide which can overcome the antimony-free effect, and also contains 3BS and 4BS. This increases battery life and ensures initial capacity.

In order to ensure the uniformity of the lead paste and the convenience of operation, with the exception of antimony trioxide and stannous sulfate, the ratio of the raw materials of the first lead paste and the second lead paste is the same, and is the same as the total lead paste. Except for antimony trioxide and stannous sulfate in the raw materials of the first lead paste and the second lead paste, the proportion of the lead powder mixed with other additives, water, and sulfuric acid is the same.

The acid addition speed and temperature control in the first lead paste and the second lead paste and the paste process are different. Specifically, the first lead paste and the preparation process are: water is added to the lead powder mixture within 2-5 minutes, Mix for 2 ~ 3min; add sulfuric acid within 10 ~ 15min, and control the maximum temperature below 50 ℃. The temperature can be controlled by the rate of acid addition and the water cooling or air cooling system of the paste machine. The second lead paste preparation process is: water is added to the lead powder mixture within 2 to 5 minutes and mixed for 2 to 3 minutes; sulfuric acid is added within 2 to 5 minutes to bring the temperature to 80 to 85 ° C, and the vacuum and paste Keep the temperature in the machine for 10-20 minutes, make 3BS into 4BS, and control the grain length of 4BS within 30μm.

Preferably, the second lead paste is prepared under a vacuum of 400 to 700 mbar, and the stirring time is 10 to 20 min. More preferably, the degree of vacuum is 483.7 mbar, the stirring time is 10 minutes, and the mass percentage content of 4BS in the second lead paste prepared under the conditions is 50 to 75%.

The specific gravity of the sulfuric acid is 1.3 to 1.4.

In step (3), firstly applying a first lead paste to form an electrode plate intermediate layer, and then coating a second lead paste on the outer surface of the first lead paste layer, the surface layer of the formed electrode plate has a high content of 4BS. 4BS produces stronger and longer needle-like crystals than 3BS, interlaced with each other, forming the skeleton of the active material, increasing the strength of the plate. Because 4BS reacts with acid slowly when soaking in acid, it slows down the sulfuric acid on the surface of the plate The sulfidation process makes the difference between the sulfation rate of the inner layer and the outer layer smaller.

Preferably, in step (3), the mass ratio of the first lead paste to the second lead paste in the electrode plate is 1: 0.4-0.6.

More preferably, the mass ratio of the first lead paste to the second lead paste in the electrode plate is 1: 0.5.

In step (4), the present invention adopts a medium temperature curing process not exceeding 55 ° C to avoid the conversion of 3BS to 4BS due to high temperature (greater than 70 ° C) and further increase in the particle size of 4BS, which can effectively control the content of 3BS and 4BS in the plate. Preferably, the curing temperature is 50-55 ° C.

In step (5), the positive electrode plate prepared by the above method is used to assemble the battery with the negative electrode plate and the separator, and the cooled electrolyte is added to reduce the temperature of the battery after the acid is added to ensure that the temperature of the battery after the acid is added does not exceed 35 ° C. Reduce the impact of temperature rise on battery plates. Preferably, the electrolytic solution is a sulfuric acid solution having a temperature of -10 ° C to 0 ° C and a density of 1.25 g / cm ³ .

During the internalization process, the battery was placed in a water bath at 25-40 ° C.

In the early stage of internalization, a large formation current density is used to change the formation process of the active material of the positive plate. Due to the conductive effect of carbon fibers, under high current density conditions, the conversion of the active material on the surface of the plate is also achieved in the early stage of formation. Forms α-PbO ₂ , α-PbO ₂ has high structural strength and is the skeleton of the active material. By adopting the above process, the ratio of α-PbO ₂ in the active material on the surface of the positive electrode plate is significantly increased, the uniformity of the active material components in the inner layer and the outer layer is improved, and the softening of the surface layer of the active material on the positive electrode plate is slowed down.

Studies have shown that, into the inner initial critical period α-PbO ₂ is formed, α-PbO ₂ is formed mainly in the early 10h, mainly due to: formed in the initial, lead paste into alkaline conditions, raw After the plate is added with acid, PbO and 4BS / 3BS are easily converted into α-PbO ₂ in the early stage of formation. Once sulfated to lead sulfate, only β-PbO ₂ is formed. Pastes sandwich skin plate of the present invention provides the content than the inner layer 4BS lead paste, and sulfation 4BS 3BS slower than the speed, slowing the rate of sulfation surface layer, the surface layer readily to create the basic form of the α-PbO ₂ condition. At the same time, the carbon fiber is added to the electrode plate, and a large current density is used, and the current density is 7-10 mA / cm ^{2. The} conversion at the ribs is realized at the same time as the transformation of the surface of the electrode plate, and the surface α-PbO ₂ content is increased. , So that the gap between the α-PbO ₂ content of the inner and outer layers becomes smaller.

Preferably, the internalization process includes the following steps: charging at a current density of 8 mA / cm ^{2 for} 420 minutes, and then charging at a current density of 5 mA / cm ^{2 for} 2208 minutes.

Another object of the present invention is to provide a long-life lead-acid battery prepared by the above method. The positive electrode plate of the lead storage battery has a sandwich structure, and the surface layer of the electrode plate has a high content of 4BS. Compared with the conventional positive electrode plate, the proportion of α-PbO _{2 in the} active material of the positive electrode plate layer provided by the present invention is significantly increased, which helps to slow down the positive electrode. The speed at which the board softens, which in turn increases the cycle life of the battery.

The invention has the beneficial effects:

In the present invention, the preparation of lead paste is completed in two parts. A first lead paste containing stannous sulfate, antimony trioxide, and 3BS and a second lead paste containing 4BS are prepared, and then a sandwich type paste operation is performed. The first lead paste is applied on the inner layer, and the second lead paste is applied on the surface layer, so that the surface layer of the electrode plate has a high content of 4BS, and the surface layer sulfate rate is changed, so that the difference between the inner layer and the outer layer is changed Small; further, using a large current density to form, due to the conductive effect of carbon fibers, a certain amount of α-PbO _{2 is} formed on the surface of the electrode plate, which improves the uniformity of the active material components in the inner layer and the outer layer. The strength of the positive electrode plate prepared under the above conditions is remarkably improved, the softening speed of the active material of the positive electrode plate is slowed, and the battery life is prolonged.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which constitute a part of this application, are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and the descriptions thereof are used to explain the present invention, and do not constitute an improper limitation on the present invention. In the drawings:

FIG. 1 is a SEM image of a first lead paste prepared in Example 1. FIG.

FIG. 2 is a SEM image of a second lead paste prepared in Example 1. FIG.

detailed description

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail with reference to the following embodiments.

As described in the background art, the existing positive electrode plate active material is prone to soften and fall off. In order to solve the above technical problems, the present application provides a method for preparing a lead storage battery. The lead storage battery includes a positive electrode plate. The lead paste material of the positive electrode plate includes lead powder, a first additive, a second additive, water, and sulfuric acid. The additives are antimony trioxide and stannous sulfate, and the second additive includes carbon fiber. The preparation method is to divide lead powder, the second additive, water and sulfuric acid into two parts respectively; Two additives, a part of water and a part of sulfuric acid are mixed, and the first reaction is performed to obtain a first lead paste containing tribasic lead sulfate; the remaining lead powder, the remaining second additive, the remaining water and the remaining sulfuric acid are mixed, And a second reaction is performed to obtain a second lead paste containing tetrabasic lead sulfate; the first lead paste is respectively coated on the two surfaces of the grid to form a first coating layer; Two lead pastes form a second coating layer; the first coating layer and the second coating layer are cured to form a positive electrode plate; and the positive electrode plate is internalized to form a required lead storage battery.

The preparation of lead paste is performed in two parts: the first part is to mix and prepare part of lead powder with the first additive (antimony trioxide and stannous sulfate), part of water and part of sulfuric acid to obtain the first lead paste, the first lead The main composition of the paste is the tribasic lead sulfate crystal phase (3BS). The second part is mixing and preparing the remaining lead powder, the remaining second additive, the remaining water and the remaining sulfuric acid to obtain a second lead paste mainly composed of a tetrabasic lead sulfate crystal phase (4BS). Firstly apply a first lead paste on the two surfaces of the grid to form a first coating (the middle layer of the positive electrode plate), and then apply a second lead paste to the outer surface of the first coating to form a second coating. (The surface layer of the positive electrode plate). The second coating has a high content of 4BS. Compared with 3BS, 4BS can produce stronger and longer needle-like crystals, which are staggered with each other, can form the skeleton of the active material, and can further increase the strength of the plate.

Since the second additive does not contain antimony trioxide and stannous sulfate, it can overcome the influence of these two substances on the formation of 4BS. The first lead paste and the second lead paste are respectively coated on the grid to form a sandwich structure. The lead paste of the positive electrode plate prepared by this method contains both stannous sulfate and stannous trioxide which can overcome the antimony-free effect. It also contains 3BS and 4BS. Therefore, the positive electrode plate having the above structure can not only improve the life of the lead storage battery, but also ensure the initial capacity.

During the preparation of the lead storage battery, the temperatures in the first reaction process and the second reaction process can be selected from those commonly used in the art. Preferably, the temperature of the first reaction is ≦ 50 ° C., and limiting the temperature of the first reaction process within the above range is beneficial to increase the weight percentage content of 3BS in the first lead paste. Preferably, the temperature of the second reaction is 80 to 85 ° C. Limiting the temperature of the second reaction process to the above range is beneficial to increase the weight percentage content of 4BS in the second lead paste.

In the preparation process of the lead storage battery, the temperature in the curing process may be selected from those commonly used in the art. In a preferred embodiment, the temperature during the curing process is ≦ 55 ° C. Limiting the curing temperature to the above range is beneficial to reduce the risk of 3BS being converted to 4BS due to excessive temperature, and at the same time suppress the further increase of the particle size of 4BS, thereby achieving the effect of effectively controlling the content of 3BS and 4BS in the positive plate. More preferably, the curing temperature is 50 to 55 ° C.

Because the composition of the first lead paste and the second lead paste are different, there are different requirements for the acid addition rate and temperature control during the corresponding preparation process. The first reaction and the second reaction can be performed in a sump machine.

In order to further increase the content of 3BS in the first lead paste, preferably, the step of preparing the first lead paste includes: mixing part of the lead powder, the first additive, and part of the second additive to obtain a first mixture; within 2 to 5 minutes , Adding part of the water to the first mixture and mixing to obtain a second mixture, the mixing time is 2 to 3 minutes; and under a condition not exceeding 50 ° C, and after partially mixing the sulfuric acid with the second mixture within 10 to 15 minutes A first reaction is performed. The reaction time of the first reaction is 1 to 6 minutes to obtain a first lead paste. In the first reaction process, the temperature can be controlled by the rate of acid addition and the water or air cooling system of the paste machine.

In order to further increase the content of 4BS in the second lead paste, preferably, the step of preparing the second lead paste includes: mixing the remaining lead powder and the remaining second additive to obtain a third mixture; within 2 to 5 minutes, the remaining Water is added to the third mixture and mixed to obtain a fourth mixture, the mixing time is 2 to 3 minutes, and the remaining sulfuric acid is mixed with the fourth mixture within 2 to 5 minutes, and then the second reaction is performed, and the second reaction is performed The time is 10-20 minutes to obtain a second lead paste.

In another preferred embodiment, the step of preparing the second lead paste includes: the second lead paste is prepared under a vacuum of 400-700 mbar, and the stirring time is 10-20 minutes. More preferably, the vacuum degree is 483.7 mbar, the stirring time is 10 minutes, and the mass percentage content of 4BS in the second lead paste prepared under the conditions is 50 to 75%.

In the early stage of internalization, a large formation current density is used to change the formation process of the active material of the positive plate. Due to the conductive effect of carbon fibers, under high current density conditions, the conversion of the active material on the surface of the plate is also achieved in the early stage of formation. Forms α-PbO ₂ , α-PbO ₂ has high structural strength and is the skeleton of the active material. By adopting the above process, the ratio of α-PbO ₂ in the active material on the surface of the positive electrode plate is significantly increased, the uniformity of the active material components in the inner layer and the outer layer is improved, and the softening of the surface layer of the active material on the positive electrode plate is slowed down. Preferably, the internalization process includes: using a positive plate to assemble a battery, adding an electrolyte to the battery, and energizing; during the internalization process, the battery is first charged at a current density of 7 to 10 mA / cm ² for 7 to 8 hours, and then The battery was charged at a current density of 3 to 5 mA / cm ² for 30 to 40 hours.

Studies have shown that, into the inner initial critical period α-PbO ₂ is formed, α-PbO ₂ is formed mainly in the early 10h, mainly due to: including into the initial, lead paste is formed under the conditions of alkaline . After the positive electrode plate is added with acid, PbO and 4BS / 3BS are easily converted into α-PbO ₂ in the early stage of formation. Once sulfated to lead sulfate, only β-PbO ₂ is formed. Pastes surface plate of the present invention provides the content than the inner layer 4BS lead paste, and sulfation 4BS 3BS slower than the speed, slowing the rate of sulfation surface layer, the surface layer is easily formed to create basic conditions α-PbO ₂ is . At the same time, the carbon fiber is added to the electrode plate, and a large current density is used, and the current density is 7-10 mA / cm ^2. At the initial stage of the transformation, the transformation at the ribs is realized, and the surface of the electrode plate is transformed to improve the surface α-PbO ₂ Content, the gap between the α-PbO ₂ content in the inner and outer layers becomes smaller. The strength of the positive electrode plate prepared under the above conditions is remarkably improved, the softening speed of the active material of the positive electrode plate is slowed, and the battery life is prolonged.

Preferably, the specific gravity of the sulfuric acid during the first reaction and the second reaction is 1.3 to 1.4.

In order to further increase the strength of the positive electrode plate and the battery life, it is more preferable that during the internalization process, the battery is first charged at a current density of 8 mA / cm ² for 7 hours, and then the battery is charged at a current density of 5 mA / cm ² for 36.8 h.

The positive electrode plate prepared by the above method is used to assemble a lead storage battery with a negative electrode plate and a separator. After adding a cooled electrolyte to the lead storage battery, the temperature of the battery after adding sulfuric acid can be reduced, and the temperature of the lead storage battery after adding sulfuric acid does not exceed 35. ℃, which is conducive to reducing the temperature increase and affecting the performance of lead battery plates. Preferably, during the internalization, the temperature of the electrolyte is -10 to 0 ° C. More preferably, the electrolytic solution is a sulfuric acid solution having a density of 1.25 g / cm ³ .

In a preferred embodiment, the lead storage battery is placed in a water bath at 25 to 40 ° C. for internalization. This is conducive to making the internalization process in a relatively stable temperature range, which is beneficial to further reduce the impact of temperature changes on the performance of the battery plate.

In a preferred embodiment, the raw materials of the lead paste include 0.05 to 0.5% antimony trioxide, 0.05 to 0.5% stannous sulfate, 0.07% carbon fiber, and 12% by weight. Water, 4 to 6% sulfuric acid, and the rest is lead powder.

In order to ensure the uniformity of the lead paste and the convenience of operation, in a preferred embodiment, the weight of the lead powder used in the first reaction and the second reaction is the same, and the second additive used in the first reaction and the second reaction is the same. The weight is the same, the weight of water used in the first reaction and the second reaction is the same, and the weight of sulfuric acid used in the first reaction and the second reaction is the same.

The reaction speed with acid is slow when 4BS is immersed in acid, which slows down the sulfation process on the surface of the electrode during the formation, which makes the difference between the sulfation speed of the inner layer and the outer layer smaller. In a preferred embodiment, a weight ratio of the first lead paste and the second lead paste is 1: 0.4 to 0.6. More preferably, the weight ratio of the first lead paste and the second lead paste is 1: 0.5.

In a preferred embodiment, the weight ratio of antimony trioxide to stannous sulfate in the first additive is 1: 0.1-10. Limiting the weight ratio of antimony trioxide to stannous sulfate within the above range is beneficial to further improve the overall performance of lead storage batteries.

According to another aspect of the present application, a lead storage battery is provided. The lead storage battery is prepared by the above preparation method.

Since the second additive does not contain antimony trioxide and stannous sulfate, it can overcome the influence of these two substances on the formation of 4BS. The first lead paste and the second lead paste were respectively coated on a grid, and the obtained positive electrode lead paste contained both stannous sulfate and stannous trioxide, which can overcome the antimony-free effect, and contained 3BS and 4BS. The lead-acid battery containing the above-mentioned positive electrode plate has high life and initial capacity.

The following further describes the present application in detail with reference to specific embodiments, which cannot be understood as limiting the scope of protection claimed by the present application.

Example 1

1. Production of the first lead paste

Add 100Kg lead powder, add 70g fiber, 0.1Kg Sb ₂ O ₃ and 0.1Kg SnSO ₄ in ordinary paste mixer, dry mix for 5min, add 12Kg water, add water for 5min, and add 10Kg specific gravity to 1.4 sulfuric acid, control the rate of acid addition, complete the addition within 15 minutes, so that the temperature of the lead paste is controlled below 50 ℃, and stir for 3 minutes after the acid is added. The formed product was observed under a scanning electron microscope. As shown in FIG. 1, a 3BS-based lead paste was formed.

2. Production of the second lead paste

First add 100Kg lead powder to the vacuum paste mixer, add 70g fiber to the lead powder, dry stir for 3min, add 12 liters of water, stir for 3min, and then add acid, the specific gravity of the acid is 1.4, and the amount of acid is 10kg, adjust The angle of the acid nozzle, the time for adding acid is controlled at 5min, and the maximum temperature is set to 80 ° C. The vacuum degree of the vacuum paste mixer is set to 483.8mbar, and then maintained for 10min during the stirring process. 50% 4BS lead paste, control time between 10min to 20min, to avoid excessive grain growth of 4BS. The formed product was observed under a scanning electron microscope, as shown in FIG. 2.

3, coated

20Ah battery grid is used for coating. Firstly, the first lead paste is coated as the inner layer of the positive electrode plate, and then the second lead paste is coated on both sides of the first lead paste. In the middle, 3BS-based lead paste is used, and the surface layer is 4BS-based lead paste. In this way, the speed of sulfation of the surface layer will be slowed down during the formation. The mass ratio of the first lead paste to the second lead paste is 1: 0.5, that is, firstly apply the first lead paste (accounting for 2/3 of the total weight of the lead paste) to the middle of the electrode plate (that is, the inner layer of the electrode plate). Then, use a second lead paste (accounting for 1/3 of the total weight of the lead paste) to coat both sides of the electrode plate (that is, the surface layer of the electrode plate).

4.Cure and battery assembly

Cured at a temperature of 55 ° C and a relative humidity of ≥85% for 48 hours, and then at a temperature of 80 ° C to 90 ° C, the relative humidity is controlled below 30% and dried for 24 hours. Separate the board and assemble the 6-DZM-20 battery (according to the new national standard GB / T 22199.2-2017, the battery model should be 6-DZF-20).

5.Internal formation process

Add a sulfuric acid solution with a density of 1.25g / cm ³ to the battery. The temperature of the sulfuric acid solution is -5 ° C. After adding acid in a vacuum, place the battery in a 25 ° C water-cooled tank. After standing for 1 hour, charge the battery according to the following process. . In the early stage, the current density was 8 mA / cm ² , and the charging time was 7 hours. In the later stage, the current density was 5 mA / cm ² , and the charging time was 36.8 h.

The XRD test technology was used to analyze the active materials on the surface and inner layers of the formed positive electrode plate. The results are shown in Table 1.

6, electrochemical performance testing

The battery charging and discharging system is as follows: 12V20Ah battery with a constant voltage of 14.7V, a current limit of 10A for 4h, and a discharge of 10A to 10.2V. When the discharge time reaches 96min, it is used as the end of battery life. The results are shown in Table 2.

Example 2

1. Production of the first lead paste

Add 100Kg of lead powder to an ordinary paste mixer, add 70g of carbon fiber, 0.1Kg of Sb ₂ O ₃ and 0.1Kg of SnSO ₄ , dry mix for 5min to obtain a first mixture;

Add 12Kg of water to the first mixture within 5 minutes and mix for 2 minutes to obtain a second mixture;

Then add 10Kg of sulfuric acid with a specific gravity of 1.4 to the second mixture, and control the acid addition rate. The addition is completed within 15 minutes, the temperature of the lead paste is controlled at 40 ° C, and the first reaction is performed. The reaction time is 3 minutes. First lead paste.

2. Production of the second lead paste

Add 100Kg of lead powder to a vacuum paste mixer, add 70g of carbon fiber to the lead powder, and dry stir for 3min to obtain a third mixture;

Add 12Kg of water to the third mixture within 2 minutes, and stir for 3 minutes to obtain a fourth mixture;

Sulfuric acid was added to the fourth mixture, the specific gravity of the sulfuric acid was 1.4, and the amount of acid was 10 kg; the angle of the acid addition nozzle was adjusted to control the time of adding acid to 5 min, and the maximum temperature was set to 85 ° C, and the vacuum The vacuum degree of the paste mixer is 483.8 mbar, and the second reaction is performed. The reaction time is 10 minutes, and a second lead paste containing 60 wt% 4BS is obtained.

3, coated

Use a grid of a 20Ah battery for coating, and first apply the first lead paste to the two surfaces of the grid respectively to obtain a first coating, which is used as the inner layer of the positive electrode plate;

Then, a second lead paste is applied on the surface of the first lead paste to form a second coating layer. Thus, a positive electrode plate is obtained. The structure of the positive electrode plate is: 3BS-based lead paste in the middle and 4BS-based lead paste in the surface layer. The weight ratio of the first lead paste to the second lead paste is 1: 0.5.

4.Cure and battery assembly

Under the conditions of a temperature of 55 ° C and a relative humidity of ≥85%, the above positive electrode plate is cured for 48 hours, and then the relative humidity is controlled below 30% under the conditions of 80 ° C to 90 ° C, and the cured positive electrode plate is dried. 24h. Divided into 6-DZM-20 batteries.

5.Internal formation process

A sulfuric acid solution having a density of 1.25 g / cm ³ and a temperature of -5 ° C was used as an electrolytic solution, and the electrolytic solution was added to the battery under a vacuum condition. The battery containing the electrolytic solution was placed in a water-cooled tank at 25 ° C and left to stand for 1 hour.

The above-mentioned battery was charged according to the following process to perform the internalization process: the current density of the previous formation was 8 mA / cm ² , and the charge was performed for 7 h; then, the current density was 5 mA / cm ² , and the charge time was 36.8 h.

6, electrochemical performance testing

The battery charging and discharging system is as follows: 12V 20Ah battery with a constant voltage of 14.7V, a current limit of 10A for 4h, and a 10A current to 10.2V. When the discharge time reaches 96min, it is used as the end of battery life. The results are shown in Table 2.

Example 3

1. Production of the first lead paste

Then add 10Kg of sulfuric acid with a specific gravity of 1.4 to the second mixture, and control the acid addition rate. The addition is completed within 15 minutes, the temperature of the lead paste is controlled at 50 ° C, the first reaction is performed, and the reaction time is 3 minutes to obtain 50% by weight 3BS First lead paste.

2. Production of the second lead paste

Sulfuric acid was added to the fourth mixture, the specific gravity of the sulfuric acid was 1.4, and the amount of acid was 10 kg; the angle of the acid adding nozzle was adjusted so that the time of adding acid was controlled to 5 min, and the maximum temperature was set to 80 ° C, and the vacuum The vacuum degree of the paste mixer is 483.8 mbar, and the second reaction is performed. The reaction time is 10 minutes, and a second lead paste containing 55 wt% 4BS is obtained.

3, coated

4.Cure and battery assembly

5.Internal formation process

6, electrochemical performance testing

Example 4

1. Production of the first lead paste

Then add 10Kg of sulfuric acid with a specific gravity of 1.4 to the above second mixture, control the acid addition rate, complete the addition within 15 minutes, control the temperature of the lead paste at 30 ° C, perform the first reaction, the reaction time is 3 minutes, and obtain 35% by weight 3BS First lead paste.

2. Production of the second lead paste

Sulfuric acid was added to the fourth mixture, the specific gravity of the sulfuric acid was 1.4, and the amount of acid was 10 kg; the angle of the acid addition nozzle was adjusted to control the time of adding acid to 5 minutes, and the maximum temperature was set to 90 ° C, and the vacuum was set The vacuum degree of the paste mixer is 483.8 mbar, and the second reaction is performed. The reaction time is 10 minutes, and a second lead paste containing 62 wt% 4BS is obtained.

3, coated

4.Cure and battery assembly

5.Internal formation process

6, electrochemical performance testing

Example 5

1. Production of the first lead paste

Then add 10Kg of sulfuric acid with a specific gravity of 1.4 to the second mixture, control the acid addition rate, and complete the addition within 15 minutes, control the temperature of the lead paste at 40 ° C, perform the first reaction, and the reaction time is 3 minutes to obtain 48 wt% 3BS First lead paste.

2. Production of the second lead paste

Sulfuric acid was added to the fourth mixture, the specific gravity of the sulfuric acid was 1.4, and the amount of acid was 10 kg; the angle of the acid addition nozzle was adjusted to control the time of adding acid to 5 min, and the maximum temperature was set to 85 ° C, and the vacuum was set The vacuum degree of the paste mixer is 483.8 mbar, and the second reaction is performed. The reaction time is 10 minutes, and a second lead paste containing 60 wt% 4BS is obtained.

3, coated

4.Cure and battery assembly

Under the conditions of a temperature of 70 ° C and a relative humidity of ≥85%, the above positive electrode plates are cured for 48 hours, and then the relative humidity is controlled below 30% at 80 ° C to 90 ° C, and the cured positive electrode plates are dried. 24h. Divided into 6-DZM-20 batteries.

5.Internal formation process

6, electrochemical performance testing

Example 6

1. Production of the first lead paste

Add 12Kg of water to the first mixture within 1 minute, and mix for 5 minutes to obtain a second mixture;

Then add 10Kg of sulfuric acid with a specific gravity of 1.4 to the second mixture, control the acid addition rate, and complete the addition within 5 minutes, control the temperature of the lead paste at 50 ° C, perform the first reaction, the reaction time is 3 minutes, and obtain 38wt% 3BS. First lead paste.

2. Production of the second lead paste

3, coated

4.Cure and battery assembly

5.Internal formation process

6, electrochemical performance testing

Example 7

1. Production of the first lead paste

Add 12Kg of water to the first mixture within 2 minutes and mix for 3 minutes to obtain a second mixture;

Then add 10Kg of sulfuric acid with a specific gravity of 1.4 to the above second mixture, control the acid addition rate, and complete the addition within 10 minutes, control the temperature of the lead paste to 50 ° C, perform the first reaction, the reaction time is 5 minutes, and obtain 48wt% 3BS First lead paste.

2. Production of the second lead paste

Add 12Kg of water to the third mixture and stir for 3min to obtain a fourth mixture;

3, coated

4.Cure and battery assembly

5.Internal formation process

6, electrochemical performance testing

Example 8

1. Production of the first lead paste

2. Production of the second lead paste

Add 12Kg of water to the third mixture within 5min, and stir for 10min to obtain a fourth mixture;

Sulfuric acid was added to the fourth mixture, the specific gravity of the sulfuric acid was 1.4, and the amount of acid was 10 kg; the angle of the acid addition nozzle was adjusted to control the time of adding acid to 10 minutes, and the maximum temperature was set to 85 ° C, and the vacuum was set The vacuum degree of the paste mixer is 483.8 mbar, and the second reaction is performed. The reaction time is 10 minutes, and a second lead paste containing 55 wt% 4BS is obtained.

3, coated

4.Cure and battery assembly

5.Internal formation process

6, electrochemical performance testing

Example 9

1. Production of the first lead paste

Then add 10Kg of sulfuric acid with a specific gravity of 1.4 to the second mixture, and control the acid addition rate. The addition is completed within 15 minutes, the temperature of the lead paste is controlled at 40 ° C, and the first reaction is performed. The reaction time is 3 minutes to obtain 3BS. First lead paste.

2. Production of the second lead paste

Sulfuric acid was added to the fourth mixture, the specific gravity of the sulfuric acid was 1.4, and the amount of acid was 10 kg; the angle of the acid addition nozzle was adjusted to control the acid addition time to 2 min, and the maximum temperature was set to 85 ° C, and the vacuum was set The vacuum degree of the paste mixer is 483.8 mbar, and the second reaction is performed. The reaction time is 10 minutes, and a second lead paste containing 62 wt% 4BS is obtained.

3, coated

4.Cure and battery assembly

5.Internal formation process

6, electrochemical performance testing

Example 10

1. Production of the first lead paste

2. Production of the second lead paste

3, coated

4.Cure and battery assembly

5.Internal formation process

The above battery was charged according to the following process to perform the internalization process: the current density of the previous formation was 10 mA / cm ² , and the charge was performed for 7 hours; then, the current density was 3 mA / cm ² , and the charge time was 40 hours.

6, electrochemical performance testing

Example 11

1. Production of the first lead paste

2. Production of the second lead paste

3, coated

4.Cure and battery assembly

5.Internal formation process

The above battery is charged according to the following process to perform the internalization process: the current density of the previous formation is 7mA / cm ² , and the charge is 8h; then, the current density is 5mA / cm ² , and the charging time is 30h.

6, electrochemical performance testing

Example 12

1. Production of the first lead paste

Then add 10Kg of sulfuric acid with a specific gravity of 1.4 to the second mixture, and control the acid addition rate. The addition is completed within 15 minutes, the temperature of the lead paste is controlled at 40 ° C, the first reaction is performed, and the reaction time is 3 minutes. First lead paste.

2. Production of the second lead paste

3, coated

Then, a second lead paste is applied on the surface of the first lead paste to form a second coating layer. Thus, a positive electrode plate is obtained. The structure of the positive electrode plate is: 3BS-based lead paste in the middle and 4BS-based lead paste in the surface layer. The weight ratio of the first lead paste to the second lead paste is 1: 0.4.

4.Cure and battery assembly

5.Internal formation process

6, electrochemical performance testing

Example 13

1. Production of the first lead paste

2. Production of the second lead paste

3, coated

Then, a second lead paste is applied on the surface of the first lead paste to form a second coating layer. Thus, a positive electrode plate is obtained. The structure of the positive electrode plate is: 3BS-based lead paste in the middle and 4BS-based lead paste in the surface layer. The weight ratio of the first lead paste to the second lead paste is 1: 0.6.

4.Cure and battery assembly

5.Internal formation process

6, electrochemical performance testing

Example 14

1. Production of the first lead paste

Add 8.5Kg of water to the first mixture within 5 minutes and mix for 5 minutes to obtain a second mixture;

Then add 5Kg of sulfuric acid with a specific gravity of 1.4 to the second mixture, control the acid addition rate, and complete the addition within 15 minutes, control the temperature of the lead paste to 45 ° C, and perform the first reaction for 3 minutes to obtain 3BS-based First lead paste.

2. Production of the second lead paste

15.5 Kg of water was added to the third mixture and stirred for 3 minutes to obtain a fourth mixture;

Sulfuric acid was added to the fourth mixture, the specific gravity of the sulfuric acid was 1.4, and the amount of acid was 15 kg; the angle of the acid adding nozzle was adjusted to control the time of adding acid to 5 min, and the maximum temperature was set to 85 ° C, and the vacuum The vacuum degree of the paste mixer is 483.8 mbar, and the second reaction is performed. The reaction time is 10 minutes to obtain a second lead paste containing 50 wt% 4BS.

3, coated

4.Cure and battery assembly

5.Internal formation process

6, electrochemical performance testing

Example 15

1. Production of the first lead paste

2. Production of the second lead paste

Sulfuric acid was added to the fourth mixture, the specific gravity of the sulfuric acid was 1.4, and the amount of acid was 10 kg; the angle of the acid addition nozzle was adjusted to control the time of adding acid to 5 min, and the maximum temperature was set to 85 ° C, and the vacuum The vacuum degree of the paste mixer is 400 mbar, and the second reaction is performed. The reaction time is 10 minutes, and a second lead paste containing 50 wt% 4BS is obtained.

3, coated

4.Cure and battery assembly

5.Internal formation process

6, electrochemical performance testing

Comparative Example 1

Prepare and assemble a 6-DZM-20 battery (see above 6-DZF-20) by referring to the method steps 1-4 of Example 1, and internalize according to the following process. Add a sulfuric acid solution with a density of 1.25g / cm ³ to the battery, sulfuric acid The temperature of the solution was 5 ° C. After the acid was added in a vacuum, the battery was placed in a water-cooled tank. After standing for 1 hour, the battery was charged according to the following process: the current density was 5 mA / cm ² , and the charging time was 48 hours.

The comparative example is that the first lead paste is used for coating, and then the method of steps 4 and 5 is used for curing, sub-plate, battery assembly, and positive electrode plate obtained by internalization.

Comparative Example 2

The difference from Example 2 is that the second lead paste preparation process is performed in a conventional and paste machine.

The ratios of α-PbO ₂ / β-PbO ₂ in the surface layer and the back layer of the positive electrode plate prepared in Examples 1 to 15 and Comparative Examples 1 to 2 were tested. The test results are shown in Table 1. Electrical performance tests were performed on the lead storage batteries prepared in Examples 1 to 15 and Comparative Examples 1 to 2, and the results are shown in Table 2.

Table 1

It can be known from Table 1 that in this embodiment, a sandwich type paste operation is used, so that the surface layer of the positive electrode plate has a high content of 4BS, and the surface layer is sulfated at a faster rate. Furthermore, a large current density is used to form the electrode surface layer α- The content of PbO ₂ increased significantly.

Table 2

From the above results, it can be seen that the use of sandwich plates can alleviate the speed of sulfation of the surface layer and increase the time for which the surface layer is kept under alkaline conditions. The use of large current density in the initial stage can make the grid in the initial stage. At the same time as the formation, the surface of the electrode plate also starts to react. Under this condition, the surface layer tends to form α-PbO ₂ , which promotes a reduction in the difference in the content of α-PbO ₂ between the surface layer and the inner layer, and improves the surface of the α-PbO ₂ . Content, which increases the strength of the surface of the plate, slows down the softening of the surface of the plate during battery cycling, and improves the cycle life of the battery.

The above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

A method for preparing a long-life lead storage battery. The lead storage battery includes a positive electrode plate. The lead paste raw materials of the positive electrode plate include lead powder, additives, water, and sulfuric acid. The additives include antimony trioxide, stannous sulfate, and The carbon fiber is characterized in that the preparation method includes the following steps:

(1) Except for antimony trioxide and stannous sulfate, the remaining additives are mixed into two parts, and antimony trioxide and stannous sulfate are added in the first part, and not added in the second part;

(2) After dry mixing part of the lead powder with the first part of the additive, add water to wet mixing, and finally add sulfuric acid to stir the reaction, and control the reaction temperature not to exceed 50 ° C to obtain the first lead paste; dry mix the remaining lead powder with the second part of the additive Then, add water and wet mix, and finally add sulfuric acid to stir the reaction, and control the reaction temperature to 80-85 ° C to obtain a second lead paste;

(3) firstly applying the first lead paste on the grid to form the inner layer of the electrode plate, and then applying the second lead paste to the surface of the inner layer of the electrode plate to obtain the electrode plate;

(4) curing at a temperature not exceeding 55 ° C to obtain a positive electrode plate;

(5) Assemble the battery, add electrolyte, and perform internalization. The initial 7-8h is charged with a current density of 7-10mA / cm 2 , and then charged at a current density of 3-5mA / cm 2 for 30-40h. At the end, the long-life lead-acid battery was produced.
The preparation method according to claim 1, characterized in that, in terms of mass percentage, the components of the lead paste of the positive electrode plate include: antimony trioxide 0.05-0.5%, stannous sulfate 0.05-0.5%, carbon fiber 0.07%, water 12%, sulfuric acid 4-6%, and the rest is lead powder.
The preparation method according to claim 2, wherein, except for the antimony trioxide and stannous sulfate in the raw materials of the first lead paste and the second lead paste, the lead powder is mixed with other additives, water, and sulfuric acid in the same proportion .
The method according to claim 1, wherein in step (3), a mass ratio of the first lead paste to the second lead paste in the electrode plate is 1: 0.4-0.6.
The method according to claim 1, wherein in step (5), the temperature of the electrolytic solution is -10 ° C-0 ° C.
The method according to claim 1, wherein in step (5), during the internalization process, the battery is placed in a water bath at 25-40 ° C.
The method according to claim 1, wherein in the step (5), the internalization process comprises the steps of: charging at a current density of 8 mA / cm 2 for 420 min, and then charging at a current density of 5 mA / cm 2 2208min.
A long-life lead-acid battery prepared by the preparation method according to any one of claims 1-7.
A method for preparing a lead storage battery, wherein the lead storage battery includes a positive electrode plate, and the raw material of the lead paste of the positive electrode plate includes lead powder, a first additive, a second additive, water, and sulfuric acid, and the first The additives are antimony trioxide and stannous sulfate, the second additive includes carbon fiber, and the preparation method includes:

Dividing the lead powder, the second additive, the water, and the sulfuric acid into two portions in order;

Mixing part of the lead powder, the first additive, part of the second additive, part of the water and part of the sulfuric acid, and performing a first reaction to obtain a first lead paste containing tribasic lead sulfate;

Mixing the remaining lead powder, the remaining second additive, the remaining water, and the remaining sulfuric acid, and performing a second reaction to obtain a second lead paste containing tetrabasic lead sulfate;

Respectively coating the first lead paste on two surfaces of the grid to form a first coating layer;

Coating a second lead paste on the surface of the first coating layer to form a second coating layer;

Curing the first coating layer and the second coating layer to form a positive electrode plate; and

The positive electrode plate is subjected to an internalization process to obtain the lead storage battery.
The preparation method according to claim 9, characterized in that the temperature of the first reaction is ≤50 ° C; the temperature of the second reaction is 80-85 ° C; and the temperature of the curing process is ≤55 ° C;

Preferably, the temperature during the curing process is 50-55 ° C.
The method according to claim 10, wherein the step of preparing the first lead paste comprises:

Part of the lead powder, the first additive, and part of the second additive are mixed to obtain a first mixture;

Adding part of the water to the first mixture and mixing within 2 to 5 minutes to obtain a second mixture with a mixing time of 2 to 3 minutes; and

After mixing part of the sulfuric acid with the second mixture within 10-15 minutes, the first reaction is performed, and the reaction time of the first reaction is 1 to 6 minutes to obtain the first lead paste.
The method according to claim 10 or 11, wherein the step of preparing the second lead paste comprises:

Mixing the remaining lead powder and the remaining second additive to obtain a third mixture;

Within 2 to 5 minutes, add the remaining water to the third mixture and mix to obtain a fourth mixture with a mixing time of 2 to 3 minutes, and

After the remaining sulfuric acid is mixed with the fourth mixture within 2 to 5 minutes, the second reaction is performed. The reaction time of the second reaction is 10 to 20 minutes to obtain the second lead paste.
The method according to any one of claims 9 to 12, wherein the internalization process comprises: assembling the positive electrode plate into the lead storage battery, and adding an electrolyte to the lead storage battery. And power on;

Preferably, the energizing process includes: charging the lead storage battery at a current density of 7 to 10 mA / cm 2 for 7 to 8 hours, and then charging the lead storage battery at a current density of 3 to 5 mA / cm 2 for 30 to 8 hours. 40h;

More preferably, the power-on process includes: first charging the lead storage battery at a current density of 8 mA / cm 2 for 7 h, and then charging the lead storage battery at a current density of 5 mA / cm 2 for 36.8 h.
The production method according to claim 13, wherein, in the formation process within the electrolyte temperature is -10 ~ 0 ℃; Preferably, the electrolyte is a density of 1.25g / cm 3 of Sulfuric acid solution.
The preparation method according to claim 13, characterized in that the lead storage battery is placed in a water bath at 25-40 ° C to perform the internalization process.
The preparation method according to any one of claims 9 to 12, characterized in that the raw material of the lead paste comprises 0.05 to 0.5% of the antimony trioxide, 0.05 as a percentage of the total weight. -0.5% of the stannous sulfate, 0.07% of the carbon fiber, 12% of the water, 4 to 6% of the sulfuric acid, and the rest are lead powder.
The method according to any one of claims 9 to 12, wherein the weight of the lead powder used in the first reaction and the second reaction is the same, and the first reaction and the The weight of the second additive used in the second reaction is the same, the weight of the water used in the first reaction and the second reaction is the same, and the weight of the water used in the first reaction and the second reaction is the same. The sulfuric acid has the same weight.
The method according to any one of claims 9 to 12, wherein a weight ratio of the first lead paste and the second lead paste is 1: 0.4 to 0.6;

Preferably, a weight ratio of the first lead paste and the second lead paste is 1: 0.5.
A lead storage battery, characterized in that the lead storage battery is made by the preparation method according to any one of claims 9 to 18.