阅读说明：本技术 铅碳电池正极活性材料及正极制备方法 (Positive electrode active material of lead-carbon battery and preparation method of positive electrode ) 是由 李爱军 施美华 汪利民 姜静波 于 2019-10-21 设计创作，主要内容包括：一种铅碳电池正极活性材料及正极制备方法,铅碳电池正极活性材料包括如下质量份的各组分：铅粉100～120份；鳞片状高纯石墨粉1～1.6份；高纯碳纳米管0.5～1.2份；聚四氟乙烯乳液80～90份；乙炔黑0.5～0.8份；红丹4～15份；活性炭1～6份；玄武岩纤维20～37份；聚丙烯纤维60～75份；纳米碳纤维20～28份；硫酸8～16份；纯水6～8份。能够改善大电流放电性能,以及活性物质利用率较高。上述铅碳电池正极的制备方法制备得到的正极碳板栅能够极其适配上述铅碳电池正极活性材料。(The positive active material of the lead-carbon battery comprises the following components in parts by mass: 100-120 parts of lead powder; 1-1.6 parts of flaky high-purity graphite powder; 0.5-1.2 parts of high-purity carbon nano tubes; 80-90 parts of polytetrafluoroethylene emulsion; 0.5-0.8 part of acetylene black; 4-15 parts of red lead; 1-6 parts of activated carbon; 20-37 parts of basalt fibers; 60-75 parts of polypropylene fiber; 20-28 parts of carbon nanofibers; 8-16 parts of sulfuric acid; 6-8 parts of pure water. Can improve the high-current discharge performance and has higher utilization rate of active substances. The positive electrode carbon grid prepared by the preparation method of the positive electrode of the lead-carbon battery can be extremely matched with the positive electrode active material of the lead-carbon battery.)

1. The positive electrode active material of the lead-carbon battery is characterized by comprising the following components in parts by mass:

2. the positive active material for a lead-carbon battery according to claim 1, wherein the lead powder has an oxidation degree of 65% to 75%;

the apparent density of the lead powder is 1.6g/cm³～1.8g/cm³。

3. The lead-carbon battery positive active material according to claim 1, wherein the sulfuric acid has a density of 1.2g/cm at 25 degrees celsius³。

4. The lead-carbon battery positive active material according to claim 1, wherein the polypropylene fiber comprises a polypropylene long fiber and/or a polypropylene short fiber;

the length of the polypropylene long fiber is 2-4 mm, and the diameter of the polypropylene long fiber is 5-15 nm;

the length of the polypropylene short fiber is 6-10 mm, and the diameter of the polypropylene short fiber is 5-15 nm.

5. The lead carbon battery positive electrode active material according to claim 1, wherein the basalt fiber includes basalt long fiber and/or basalt short fiber;

the length of the basalt long fiber is 4 mm-6 mm, and the diameter of the basalt long fiber is 6 nm-20 nm;

the length of the basalt short fiber is 8-15 mm, and the diameter of the basalt short fiber is 6-20 nm.

6. The preparation method of the lead-carbon battery positive electrode is characterized by comprising the following steps:

providing a carbon material;

adding an ethanol aqueous solution into the carbon material, and stirring to obtain carbon slurry;

adding a binder into the carbon slurry, and stirring to obtain mixed slurry;

filling the mixed slurry into a grid mold, and drying the grid mold filled with the mixed slurry at the temperature of 130-200 ℃;

cooling the grid mold filled with the mixed slurry, and taking out a carbon plate blank;

carrying out normal-temperature compacting and shape fixing operation on the carbon plate blank under the pressure condition of 300-350 kpa;

heating the carbon plate blank to 160-180 ℃ under the pressure condition of 300-350 kpa to perform high-temperature compacting and shaping operation on the carbon plate blank to obtain a carbon plate grid;

performing lead electroplating operation on the surface of the carbon grid to obtain a surface lead carbon grid;

immersing the surface lead carbon grid into a mixed solution of graphene and water, fishing out the surface lead carbon grid with graphene particles adhered to the surface, and performing hot air drying operation;

drying the surface lead carbon grid with the graphene particles adhered to the surface at 75-80 ℃ to obtain a positive carbon grid;

preparing the positive electrode active material of the lead-carbon battery according to any one of claims 1 to 5;

and filling the positive active material of the lead-carbon battery into the positive carbon grid, and drying and curing to obtain the positive electrode of the lead-carbon battery.

7. The method for producing a lead-carbon battery positive electrode according to claim 6, wherein the duration of the normal-temperature compacting operation is 1 to 2.5 hours.

8. The method for producing a positive electrode for a lead-carbon battery according to claim 6, wherein the duration of the high-temperature compacting operation is 9 to 12 hours.

9. The method for preparing the positive electrode of the lead-carbon battery according to claim 6, wherein the method for preparing the mixed solution of graphene and water comprises the following steps: preheating water to 75-80 ℃; adding a dispersing agent into water in advance, stirring and mixing, and then adding graphene particles to obtain a mixed solution of graphene and water;

and keeping the temperature of the mixed solution of the graphene and the water at 75-80 ℃, and immersing the surface lead carbon grid into the mixed solution of the graphene and the water.

10. The method for producing a positive electrode for a lead-carbon battery according to claim 6, wherein the carbon grid is further subjected to an operation of electroplating lead on its surface;

carrying out roughening treatment on the surface of the carbon grid;

carrying out oil removal operation on the carbon grid;

washing the carbon grid with water;

and drying the carbon grid.

Technical Field

The invention relates to the technical field of lead-carbon batteries, in particular to a lead-carbon battery positive electrode active material and a preparation method of a positive electrode.

Background

At present, the electrodes of lead-acid batteries are mainly made of lead and its oxides, and the electrolyte is a sulfuric acid solution. Since 1859 the lead-acid storage battery invented by frant of french americans, the lead-acid battery has undergone more than 150 years of development process, the lead-acid battery has low cost, long service life and good safety performance, and the recovery rate of the waste battery is as high as more than 95%, so the lead-acid battery is always the most widely used product in the battery field.

With the rapid development of electric automobiles and electric bicycles, a novel storage battery based on a lead-carbon technology, namely a lead-carbon battery, is gradually developed, activated carbon is added into lead paste of a negative electrode of the lead-acid battery to serve as a buffer material, and the carbon material is a high-quality material for storing, retaining and releasing static charges and can instantly gather and store a large amount of charges, so that the battery has higher power density, can finish charging in shorter time, can work under high multiplying power and better meets the development requirements of electric vehicles.

The lead-carbon battery is generally manufactured by using lead dioxide (PbO2) as a positive plate, mixing lead powder, water, sulfuric acid, graphite, phosphoric acid, acrylic or polypropylene, magnesium sulfate and other raw materials to form positive lead paste, namely coating a positive active material on a positive plate grid, and drying the positive plate grid.

However, the positive active material of the traditional lead-carbon battery has the problem of poor high-current discharge performance, and the utilization rate of the active material is low.

Disclosure of Invention

Therefore, it is necessary to provide a positive electrode active material for a lead-carbon battery and a positive electrode preparation method, which can improve the high-current discharge performance and have a high active material utilization rate.

The positive electrode active material of the lead-carbon battery comprises the following components in parts by mass:

in one embodiment, the oxidation degree of the lead powder is 65-75%;

the apparent density of the lead powder is 1.6g/cm³～1.8g/cm³。

In one embodiment, the sulfuric acid has a density of 1.2g/cm at 25 degrees Celsius³。

In one embodiment, the polypropylene fibers comprise polypropylene long fibers and/or polypropylene short fibers;

the length of the polypropylene long fiber is 2-4 mm, and the diameter of the polypropylene long fiber is 5-15 nm;

the length of the polypropylene short fiber is 6-10 mm, and the diameter of the polypropylene short fiber is 5-15 nm.

In one embodiment, the basalt fibers comprise basalt long fibers and/or basalt short fibers;

the length of the basalt long fiber is 4 mm-6 mm, and the diameter of the basalt long fiber is 6 nm-20 nm;

the length of the basalt short fiber is 8-15 mm, and the diameter of the basalt short fiber is 6-20 nm.

A preparation method of a lead-carbon battery positive electrode comprises the following steps:

providing a carbon material;

adding an ethanol aqueous solution into the carbon material, and stirring to obtain carbon slurry;

adding a binder into the carbon slurry, and stirring to obtain mixed slurry;

filling the mixed slurry into a grid mold, and drying the grid mold filled with the mixed slurry at the temperature of 130-200 ℃;

cooling the grid mold filled with the mixed slurry, and taking out a carbon plate blank;

carrying out normal-temperature compacting and shape fixing operation on the carbon plate blank under the pressure condition of 300-350 kpa;

heating the carbon plate blank to 160-180 ℃ under the pressure condition of 300-350 kpa to perform high-temperature compacting and shaping operation on the carbon plate blank to obtain a carbon plate grid;

performing lead electroplating operation on the surface of the carbon grid to obtain a surface lead carbon grid;

immersing the surface lead carbon grid into a mixed solution of graphene and water, fishing out the surface lead carbon grid with graphene particles adhered to the surface, and performing hot air drying operation;

drying the surface lead carbon grid with the graphene particles adhered to the surface at 75-80 ℃ to obtain a positive carbon grid;

preparing the positive electrode active material of the lead-carbon battery;

and filling the positive active material of the lead-carbon battery into the positive carbon grid, and drying and curing to obtain the positive electrode of the lead-carbon battery.

In one embodiment, the duration of the normal-temperature compacting operation is 1 hour to 2.5 hours.

In one embodiment, the duration of the high-temperature compacting operation is 9 to 12 hours.

In one embodiment, the preparation method of the mixed solution of graphene and water comprises the following steps: preheating water to 75-80 ℃; adding a dispersing agent into water in advance, stirring and mixing, and then adding graphene particles to obtain a mixed solution of graphene and water;

and keeping the temperature of the mixed solution of the graphene and the water at 75-80 ℃, and immersing the surface lead carbon grid into the mixed solution of the graphene and the water.

In one embodiment, before the lead electroplating operation is carried out on the surface of the carbon grid, the following operations are also carried out on the carbon grid;

carrying out roughening treatment on the surface of the carbon grid;

carrying out oil removal operation on the carbon grid;

washing the carbon grid with water;

and drying the carbon grid.

Compared with the traditional lead-carbon battery active material, the lead-carbon battery positive active material has the advantages that the conductive performance is greatly improved by adding the flaky high-purity graphite powder, the high-purity carbon nano tubes and the acetylene black, the high-current discharge performance can be improved, the content of sulfuric acid is not high, the sulfuric acid is easy to form and penetrate, and the utilization rate of active substances can be further improved. Because the high-current discharge performance is better, the red lead and the activated carbon are introduced, so that the porosity and the fluffiness of the positive active material of the lead-carbon battery can be fully ensured, the adsorption of the positive active material to the electrolyte is stronger, and the continuity and the safety of the reaction are also considered. The flaky high-purity graphite powder has a better surface effect, can be in more sufficient contact with lead powder, has a larger surface area, and the high-purity carbon nano tube also has the effect, so that the high-current discharge performance is further improved. The acetylene black has both electrolyte adsorption performance and large-current discharge performance.

And meanwhile, the polytetrafluoroethylene, the basalt fiber, the polypropylene fiber and the carbon nanofiber can be matched with each other, and a plurality of the components form a uniform net structure, so that the toughness and the impact resistance of the positive active material of the lead-carbon battery are improved. Furthermore, the carbon nanofibers can serve as a conductor to reinforce the charge and discharge performance and can also play a role in structure reinforcement, thereby achieving two purposes.

Finally, because the basalt fiber, the polypropylene fiber, the carbon nanofiber and the binder form a net structure, and the lead powder, the flaky high-purity graphite powder, the high-purity carbon nanotube, the acetylene black, the red lead and the activated carbon are granular or flaky structures, the lead powder, the flaky high-purity graphite powder, the high-purity carbon nanotube, the acetylene black, the red lead and the activated carbon can be well filled into net-shaped gaps, so that the conductivity can be improved, and the conductive carbon also has good mechanical properties.

The positive electrode carbon grid prepared by the preparation method of the positive electrode of the lead-carbon battery can be extremely matched with the positive electrode active material of the lead-carbon battery.

Drawings

Fig. 1 is a flow chart illustrating steps of a method for manufacturing a positive electrode for a lead-carbon battery according to an embodiment.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.

The positive electrode active material of the lead-carbon battery comprises the following components in parts by mass:

compared with the traditional lead-carbon battery active material, the lead-carbon battery positive active material has the advantages that the conductive performance is greatly improved by adding the flaky high-purity graphite powder, the high-purity carbon nano tubes and the acetylene black, the high-current discharge performance can be improved, the content of sulfuric acid is not high, the sulfuric acid is easy to form and penetrate, and the utilization rate of active substances can be further improved. Because the high-current discharge performance is better, the red lead and the activated carbon are introduced, so that the porosity and the fluffiness of the positive active material of the lead-carbon battery can be fully ensured, the adsorption of the positive active material to the electrolyte is stronger, and the continuity and the safety of the reaction are also considered. The flaky high-purity graphite powder has a better surface effect, can be in more sufficient contact with lead powder, has a larger surface area, and the high-purity carbon nano tube also has the effect, so that the high-current discharge performance is further improved. The acetylene black has both electrolyte adsorption performance and large-current discharge performance.

And meanwhile, the polytetrafluoroethylene, the basalt fiber, the polypropylene fiber and the carbon nanofiber can be matched with each other, and a plurality of the components form a uniform net structure, so that the toughness and the impact resistance of the positive active material of the lead-carbon battery are improved. Furthermore, the carbon nanofibers can serve as a conductor to reinforce the charge and discharge performance and can also play a role in structure reinforcement, thereby achieving two purposes.

Finally, because the basalt fiber, the polypropylene fiber, the carbon nanofiber and the binder form a net structure, and the lead powder, the flaky high-purity graphite powder, the high-purity carbon nanotube, the acetylene black, the red lead and the activated carbon are granular or flaky structures, the lead powder, the flaky high-purity graphite powder, the high-purity carbon nanotube, the acetylene black, the red lead and the activated carbon can be well filled into net-shaped gaps, so that the conductivity can be improved, and the conductive carbon also has good mechanical properties.

In one embodiment, the oxidation degree of the lead powder is 65% to 75%; the apparent density of the lead powder is 1.6g/cm³～1.8g/cm³。

In one embodiment, the sulfuric acid has a density of 1.2g/cm at 25 degrees Celsius³。

In one embodiment, the polypropylene fibers comprise polypropylene long fibers and/or polypropylene short fibers; the length of the polypropylene long fiber is 2-4 mm, and the diameter of the polypropylene long fiber is 5-15 nm; the length of the polypropylene short fiber is 6-10 mm, and the diameter of the polypropylene short fiber is 5-15 nm. The basalt fibers comprise basalt long fibers and/or basalt short fibers; the length of the basalt long fiber is 4 mm-6 mm, and the diameter of the basalt long fiber is 6 nm-20 nm; the length of the basalt short fiber is 8-15 mm, and the diameter of the basalt short fiber is 6-20 nm. Further, the polypropylene fiber comprises polypropylene long fiber and polypropylene short fiber; the length of the polypropylene long fiber is 2-4 mm, and the diameter of the polypropylene long fiber is 5-15 nm; the length of the polypropylene short fiber is 6-10 mm, and the diameter of the polypropylene short fiber is 5-15 nm; the basalt fibers comprise basalt long fibers and basalt short fibers; the length of the basalt long fiber is 4 mm-6 mm, and the diameter of the basalt long fiber is 6 nm-20 nm; the length of the basalt short fiber is 8-15 mm, the diameter of the basalt short fiber is 6-20 nm, and therefore, the basalt short fiber and the polypropylene short fiber are used in a composite mode, the long fiber and the short fiber form a main framework of a net structure, the long fiber and polytetrafluoroethylene form a main framework, the short fiber can be filled to well solve the problem that the space of a net-shaped inner cavity is large due to the long fiber, and the lead-carbon battery positive electrode active material can be better made of a granular or sheet structure raw material. Further, in the basalt fiber and the polypropylene fiber, the mass ratio of the long fibers to the short fibers is 3: 1.

as shown in fig. 1, a method for preparing a positive electrode of a lead-carbon battery according to an embodiment includes the steps of:

s110: a carbon material is provided.

In one embodiment, the carbon material is at least one of flygraphite, all-carbon aerogel, carbon foam, conductive graphite, carbon black, and acetylene black; further, the carbon materials include flygraphite, all-carbon aerogel, carbon foam, conductive graphite, carbon black, and acetylene black; furthermore, the mass ratio of the flying graphite to the all-carbon aerogel to the foam carbon to the conductive graphite to the carbon black to the acetylene black is (4-20): (5-20): (20-70): (2-5): (1-3): (0.2-0.3), the carbon material prepared according to the proportion can effectively reduce the overall weight of the carbon grid, and can ensure the mechanical property of the carbon grid, which is about half of the weight of a common alloy grid.

S120: and adding an ethanol aqueous solution into the carbon material, and stirring to obtain carbon slurry.

Of course, when the carbon material is added to the ethanol aqueous solution for stirring operation, a proper amount of dispersant may be further added to obtain carbon slurry with higher mixing uniformity.

S130: and adding a binder into the carbon slurry, and stirring to obtain a mixed slurry.

By adding the binder into the carbon slurry and performing stirring operation, the adhesion between carbon materials can be higher, and carbon plate blanks which are not easy to disperse can be obtained.

In one embodiment, the binder is at least one of polytetrafluoroethylene, carboxymethyl cellulose, and neoprene, and further, the binder includes polytetrafluoroethylene, carboxymethyl cellulose, and neoprene.

S140: and filling the mixed slurry into a grid mold, and drying the grid mold filled with the mixed slurry at the temperature of 130-200 ℃.

The pre-forming operation of the grid can be performed by filling the mixed slurry into a grid mold, and the drying can remove water and organic solvents.

S150: and cooling the grid mold filled with the mixed slurry, and taking out the carbon plate blank.

S160: and carrying out normal-temperature compacting and shaping operation on the carbon plate blank under the pressure condition of 300-350 kpa.

The normal-temperature compacting and shape fixing operation, namely the primary pre-pressing operation, is carried out on the carbon plate blank under the pressure condition of 300-350 kpa, so that a larger gap or a larger cavity caused by die forming or raw materials per se and the like can be improved under the milder pressure and temperature, the overall porosity of the carbon plate blank is better, and the problem of uneven local compacting effect caused by directly carrying out high-temperature compacting and shape fixing is avoided. And the deformation degree can be reduced, so that the grid metallographic structure is more uniform and compact.

S170: and heating the carbon plate blank to 160-180 ℃ under the pressure condition of 300-350 kpa to perform high-temperature compacting and shaping operation on the carbon plate blank to obtain the carbon plate grid.

And combining the normal-temperature compacting and shaping operation to ensure that the whole porosity of the carbon plate blank reaches a better degree, then performing high-temperature compacting and shaping operation, changing the plasticity of the carbon plate blank through temperature, namely at least improving the feasible denaturation and exhaust performance, further improving the compactness of the carbon plate grid, effectively eliminating irregular gaps or cavities, and improving the bonding and combining performance between carbon materials, so that the conductivity of the carbon plate grid is better, and the high-current charge and discharge performance of the anode active material can be matched.

In one embodiment, the duration of the normal-temperature compacting and solidifying operation is 1 to 2.5 hours; the duration time of the high-temperature compaction and setting operation is 9-12 hours, and the compaction and setting operation can be further carried out.

S180: and carrying out lead electroplating operation on the surface of the carbon grid to obtain the surface lead carbon grid.

Through the step S180, a lead layer, i.e., a surface lead layer, can be electroplated on the surface of the carbon grid, and the affinity between the active material of the lead-carbon battery and the carbon grid can be effectively improved compared with the all-carbon grid.

In one embodiment, before the lead electroplating operation is carried out on the surface of the carbon grid, the following operations are also carried out on the carbon grid; carrying out roughening treatment on the surface of the carbon grid; carrying out oil removal operation on the carbon grid; washing the carbon grid with water; and the carbon grid is dried, so that the lead effect can be improved, and the adhesion of a lead layer is better.

In particular, in order to improve the adhesion of the electroplated lead layer on the carbon grid and reduce the peeling and loosening problems, for example, before the surface of the carbon grid is subjected to the lead electroplating operation, the surface of the carbon grid is also subjected to roughening treatment by using a roughening solution so as to improve the roughness and the effective surface area; meanwhile, cleaning solution is adopted to remove surface impurities, an electroplated copper layer is adopted to bottom, and then the surface of the electroplated copper layer is subjected to lead electroplating operation to obtain the surface lead carbon grid.

S190: and immersing the surface lead carbon grid into a mixed solution of graphene and water, fishing out the surface lead carbon grid with graphene particles adhered to the surface, and performing hot air drying operation.

In one embodiment, the method for preparing the mixed solution of graphene and water includes the following steps: preheating water to 75-80 ℃; adding a dispersing agent into water in advance, stirring and mixing, and then adding graphene particles to obtain a mixed solution of graphene and water; keeping the temperature of the mixed liquid of the graphene and the water at 75-80 ℃, and immersing the surface lead carbon grid into the mixed liquid of the graphene and the water, so that the dispersity of the graphene can be improved, and the adhesion of the grid can be improved.

S200: and drying the surface lead carbon grid with the graphene particles adhered to the surface at 75-80 ℃ to obtain the positive carbon grid.

It should be particularly noted that, by sequentially performing the operations of immersing the mixed solution and drying at medium and low temperatures, the graphene particles can be sparsely and uniformly distributed on the surface lead layer, and the graphene particles are matched with the above-mentioned conductor of the positive active material of the lead-carbon battery, such as flaky high-purity graphite powder, high-purity carbon nanotubes, carbon nanofibers, and the like, so that the internal resistance of contact between the active material and the grid can be reduced, the electrical properties are better, and meanwhile, the graphene particles protrude out of the surface lead layer, so that the positive active material of the lead-carbon battery after being locked and cured can be better supported, and the problems of softening, loosening and collapsing are not easy to occur.

Furthermore, the thickness of the surface lead layer is controlled to be 2-5 microns, and the positive carbon grid is extruded, so that the graphene particles can be better embedded into the surface lead layer.

S210: preparing a positive electrode active material of the lead-carbon battery; the positive electrode active material of the lead-carbon battery comprises the following components in parts by mass: 100-120 parts of lead powder; 1-1.6 parts of flaky high-purity graphite powder; 0.5-1.2 parts of high-purity carbon nano tubes; 80-90 parts of polytetrafluoroethylene emulsion; 0.5-0.8 part of acetylene black; 4-15 parts of red lead; 1-6 parts of activated carbon; 20-37 parts of basalt fibers; 60-75 parts of polypropylene fiber; 20-28 parts of carbon nanofibers; 8-16 parts of sulfuric acid; 6-8 parts of pure water.

S220: and filling the positive active material of the lead-carbon battery into the positive carbon grid, and drying and curing to obtain the positive electrode of the lead-carbon battery.

The positive electrode of the lead-carbon battery can be directly used in the lead-carbon battery, and is separated from the negative electrode of the lead-carbon battery by a diaphragm during assembly.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.