阅读说明：本技术 一种铅蓄电池正极板的制备方法 (Preparation method of positive plate of lead storage battery ) 是由 刘克宇 方明学 庄建 王超 宋文龙 洪清富 于 2020-03-27 设计创作，主要内容包括：本发明公开了一种铅蓄电池正极板的制备方法,属于蓄电池技术领域。所述制备方法包括：(1)将泡沫铅材料经若干道压延后冲切得到板栅格子体,沿板栅格子体的一宽边压铸铅锡合金形成上边框和极耳,制得正极板栅；(2)往正极板栅上喷涂低酸或无酸的铅膏,再浸酸；(3)将极板从酸液中取出,极板表面覆盖涂板纸,叠放置于固化室固化,制得所述铅蓄电池正极板。本发明利用高孔率、大孔径的泡沫铅材料,通过多道压延,实现极板薄型化,同时孔隙结构更丰富复杂,可实现低酸低粘度铅膏喷涂,而且极板电流分布更均匀,显著提高活性物质利用率和大电流充放电能力；叠片固化,可实现低温低湿固化,降低能源消耗和固化工艺的过程控制难度。(The invention discloses a preparation method of a positive plate of a lead storage battery, and belongs to the technical field of storage batteries. The preparation method comprises the following steps: (1) die-cutting the foamed lead material after a plurality of pressing and rolling to obtain a grid lattice body, and die-casting lead-tin alloy along one wide edge of the grid lattice body to form an upper frame and a lug so as to prepare a positive grid; (2) spraying low-acid or acid-free lead plaster on the positive grid, and then soaking in acid; (3) and taking the polar plate out of the acid liquor, covering the surface of the polar plate with coated paper, stacking the polar plate and placing the polar plate in a curing chamber for curing, and thus obtaining the positive plate of the lead storage battery. According to the invention, a foamed lead material with high porosity and large pore diameter is utilized, the thinning of the polar plate is realized through multiple rolling, meanwhile, the pore structure is richer and more complex, the spraying of low-acid low-viscosity lead paste can be realized, the current distribution of the polar plate is more uniform, and the utilization rate of active substances and the large-current charging and discharging capacity are obviously improved; the lamination is solidified, so that low-temperature and low-humidity solidification can be realized, and the energy consumption and the process control difficulty of the solidification process are reduced.)

1. The preparation method of the positive plate of the lead storage battery is characterized by comprising the following steps:

(1) die-cutting the foamed lead material after a plurality of pressing and rolling to obtain a grid lattice body, and die-casting lead-tin alloy along one wide edge of the grid lattice body to form an upper frame and a lug so as to prepare a positive grid;

the porosity of the foamed lead material is 90-95%, the pore diameter is larger than or equal to 6mm, and the calendering conditions are as follows: the reduction rate of each pass is less than or equal to 10 percent, and the total reduction rate is less than or equal to 60 percent;

(2) spraying lead plaster on the positive grid, and then soaking in acid;

the lead plaster comprises lead powder, sulfuric acid solution and water, wherein the lead powder accounts for 100 parts by weight, and the concentration of the lead powder is 1.4g/cm³0-5 parts of sulfuric acid solution and 18-25 parts of water;

(3) and taking the polar plate out of the acid liquor, covering the surface of the polar plate with coated paper, stacking the polar plate and placing the polar plate in a curing chamber for curing, and thus obtaining the positive plate of the lead storage battery.

2. The method for preparing the positive plate of the lead storage battery according to claim 1, wherein in the step (1), 4 to 9 calendering steps are performed.

3. The method for preparing the positive plate of the lead storage battery according to claim 1, wherein in the step (1), the mass percentage of tin in the lead-tin alloy is 1.8-30%.

4. The method for preparing the positive plate of the lead storage battery as claimed in claim 3, wherein the width of the overlapping part of the upper frame and the grid lattice body is 3-4 mm.

5. The method for preparing the positive plate of the lead storage battery according to claim 4, wherein the pressure of the die casting is 30-40 MPa, and the temperature is 480 +/-20 ℃.

6. The method for preparing the positive plate of the lead storage battery according to claim 1, wherein in the step (2), the components of the lead paste, based on 100 parts by weight of lead powder, comprise: 100 parts of lead powder, 1.4g/cm³2.5 to 4.2 parts of sulfuric acid, 19.3 to 20.5 parts of water and 0.05 to 0.1 part of teflon solution with the mass concentration of 15 to 30 percent.

7. The method for preparing the positive plate of the lead storage battery according to claim 1, wherein in the step (2), the spraying pressure is 0.04 to 0.08 MPa.

8. The method for preparing the positive plate of the lead storage battery according to claim 1, wherein the pickling is performed at a density of 1.08-1.20 g/cm³The pickling time of the sulfuric acid solution is 30-60 s.

9. The method for preparing the positive plate of the lead storage battery as claimed in claim 1, wherein in the step (3), the curing temperature is 35-45 ℃, the relative humidity is 30-50%, and the curing time is 48-72 h.

Technical Field

The invention relates to the technical field of storage batteries, in particular to a preparation method of a positive plate of a lead storage battery.

Background

The lead storage battery is widely applied to the fields of communication, electric power, UPS power supply and the like because of the advantages of mature technology, low price, large monomer capacity, high safety and the like, and is the secondary battery with the largest consumption at present.

The field of traditional communication, UPS backup power supply and the like is mainly used for floating charging, and the main failure mode of the storage battery under the using condition is corrosion of a positive plate grid. The fields of power energy storage and the like are mainly recycled, and the main failure mode of the storage battery under the using condition is softening and falling of the positive lead plaster.

In recent years, with the rise and high-speed development of the internet and electronic commerce, an IDC machine room is greatly built, a storage battery is mostly powered on for a short time, the power supply time is 5-10 min generally, and the acceptance standard of a storage battery pack is 15min constant-power discharge. Meanwhile, due to the large data processing capacity, the backup power supply of the IDC machine room is basically a high-voltage system, the capacity is large, and the storage battery is required to have higher specific energy and specific power so as to reduce the occupation of an installation site, the load of a unit area of a floor and the like.

Aiming at the use characteristics and failure modes of the storage battery in the typical application scene, a storage battery with a more corrosion-resistant positive grid, a positive lead paste which is not easy to soften and fall off and a higher specific energy needs to be developed.

The slab lattice of the present lead accumulator is mainly cast slab lattice of lead-calcium alloy, which has heavy weight and results in low specific energy of the accumulator. The weight of the polar plate accounts for 70 percent of the weight of the whole battery, in order to reduce the weight of the battery and improve the utilization rate of active substances, technicians at home and abroad mainly improve the structure and the material of the plate grids, and invent a plurality of novel plate grid materials such as copper expanded grid, lead cloth and the like in succession, and the mass specific energy of the novel plate grid materials can be improved to 50 Wh/Kg.

The foamed lead has a good net-shaped porous structure, high porosity, high specific surface area and light volume density, so that when the foamed lead is used as an electrode grid of a lead storage battery, the utilization rate of an electrode active substance of the lead storage battery can be greatly improved, and the foamed lead is paid much attention. For example, patent document CN 203589138U discloses a high-performance lead-acid battery grid, which includes a tab fixed on the outer side of a frame, and a foamed lead current collector disposed inside the frame, the foamed lead current collector being connected with the frame by electrodeposition; patent document CN 110148710 a also discloses that the battery grid is made of foamed lead material to reduce the grid mass, and the three-dimensional network structure of foamed lead increases the contact area with lead paste, and improves the utilization rate of active substances.

However, in actual production, there are problems as follows: the polar plate can not be thinned (the thickness of a foam lead material is generally more than 6mm, and the thickness of a foam lead plate grid prepared by the existing method is thicker), the rate performance of the prepared battery is poor, the casting reliability of the pole lug is low (the pole lug has poor strength, and the defects of insufficient solder, air holes and the like are easy to occur), the using amount of lead and the weight of a finished battery can be greatly increased by adopting a mode of casting the pole lug and a peripheral frame, and the industrial application of the battery is seriously influenced.

Disclosure of Invention

The invention aims to provide a method for preparing a positive plate of a lead storage battery, which has low requirements on process conditions and stable and reliable performance of a finished plate.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of a positive plate of a lead storage battery comprises the following steps:

(1) die-cutting the foamed lead material after a plurality of pressing and rolling to obtain a grid lattice body, and die-casting lead-tin alloy along one wide edge of the grid lattice body to form an upper frame and a lug so as to prepare a positive grid;

the porosity of the foamed lead material is 90-95%, the pore diameter is larger than or equal to 6mm, and the calendering conditions are as follows: the reduction rate of each pass is less than or equal to 10 percent, and the total reduction rate is less than or equal to 60 percent;

(2) spraying lead plaster on the positive grid, and then soaking in acid;

the lead plaster comprises lead powder, sulfuric acid solution and water, wherein the lead powder accounts for 100 parts by weight, and the concentration of the lead powder is 1.4g/cm³0-5 parts of sulfuric acid solution and 18-25 parts of water;

(3) and taking the polar plate out of the acid liquor, covering the surface of the polar plate with coated paper, stacking the polar plate and placing the polar plate in a curing chamber for curing, and thus obtaining the positive plate of the lead storage battery.

In the step (1), according to the size of the existing pole plate, the foamed lead material with high porosity and large aperture is rolled to the required thickness, and is punched into the required size, so that the grid lattice body is prepared. The weight of the grid is far less than that of the traditional cast grid by adopting a foamed lead material, so that the weight of the storage battery and the consumption of lead are greatly reduced; the corrosion resistance of the lead-calcium alloy plate grid is superior to that of the traditional lead-calcium alloy plate grid.

And during calendering, the number of calendering channels and the reduction rate per time are controlled, so that the internal pores of the material are more abundant and complex, the contact area of the three-dimensional network pore structure with lead paste is increased, and the utilization rate of active substances is improved.

The thickness of the foamed lead material is 5-9 mm, the porosity is 90-95%, and the pore diameter is larger than or equal to 6 mm.

Preferably, the mixture is subjected to 4-9 rolling.

The invention adopts the die-casting technology to connect the upper frame and the lug of the lead-tin alloy on one side of the grid lattice body, and the upper frame is effectively connected with the foamed lead grid and the lug, thereby being beneficial to the concentration of current to the lug.

Preferably, the mass percent of tin in the lead-tin alloy is 1.8-30%.

The upper frame is arranged on one side of the grid daughter of the foam lead plate, so that the consumption of lead is reduced. The upper frame accounts for 1.2% -3% of the height of the positive grid. The width of the overlapping part of the upper frame and the grid lattice body is 3-4 mm.

Preferably, the pressure of the die casting is 30-40 MPa, and the temperature is 480 +/-20 ℃. The reliability and the production efficiency of the casting finished product are ensured, and the precision, the surface finish degree, the mechanical strength and the like of the pole lug size are ensured.

In the step (2), low-acid or acid-free lead paste is sprayed in the grid cavity of the positive plate by using a spray gun and then is soaked in acid.

Preferably, the lead plaster comprises the following components in parts by weight based on 100 parts by weight of lead powder: 100 parts of lead powder, 1.4g/cm³2.5 to 4.2 parts of sulfuric acid, 19.3 to 20.5 parts of water and 0.05 to 0.1 part of teflon solution with the mass concentration of 15 to 30 percent.

The common short fibers are omitted in the lead plaster additive, and the low-mass-fraction teflon solution is added, so that pores of an active substance are developed, the high-rate charge and discharge performance is further improved, and meanwhile, the temperature rise of a battery is increased during high-rate charge and discharge, and the teflon is more difficult to degrade than the traditional short fibers.

The high-pressure spraying is favorable for fully filling the lead paste into the plate grid cavity, and preferably, the spraying pressure is 0.04-0.08 MPa.

The pickling adopts the density of 1.08-1.20 g/cm³The pickling time of the sulfuric acid solution is 30-60 s.

In the step (3), the lamination is solidified after the coated paperboard is coated, so that the heat generated by the reaction of the polar plate is fully utilized, the polar plate is more beneficial to moisturizing, the low-temperature and low-humidity solidification can be realized, and the energy consumption is reduced.

Preferably, the curing temperature is 35-45 ℃, the relative humidity is 30-50%, and the curing time is 48-72 h.

The invention has the following beneficial effects:

(1) according to the invention, a foam lead material with high porosity and large pore diameter is utilized, a three-dimensional network structure with richer and more complex pores is formed through calendering, the current distribution of a polar plate is more uniform, the utilization rate of active substances and the large-current charging and discharging capacity are obviously improved, and compared with a two-dimensional pore structure of a traditional cast grid, the lead plaster is more difficult to fall off.

(2) The foamed lead material is difficult to thin, the pole plate is thin through multiple rolling, meanwhile, the pore structure is rich, the low-acid low-viscosity lead paste spraying can be realized, and the utilization rate and the high-rate discharge performance of active substances are further improved through the low-acid low-viscosity lead paste.

(3) The invention adopts lamination curing, can realize low-temperature and low-humidity curing, and reduces energy consumption and the process control difficulty of the curing process.

Detailed Description

The present invention will be further described with reference to the following specific examples, but the present invention is not limited thereto.