CN107403934B

CN107403934B - Short fiber for lead-acid storage battery plate

Info

Publication number: CN107403934B
Application number: CN201710746719.3A
Authority: CN
Inventors: 邢延超; 班涛伟; 刘文林; 曹贵发; 周龙金; 苏守前
Original assignee: SHANDONG JINKELI POWER SOURCES TECHNOLOGY CO LTD
Current assignee: SHANDONG JINKELI POWER SOURCES TECHNOLOGY CO LTD
Priority date: 2017-08-27
Filing date: 2017-08-27
Publication date: 2020-09-18
Anticipated expiration: 2037-08-27
Also published as: CN107403934A

Abstract

The invention discloses a short fiber for a lead-acid storage battery plate, which comprises a plurality of organic fibers with the length of less than or equal to 6mm, and is characterized in that the single fiber fineness of the organic fibers is 0.15-0.8D; meanwhile, the floating powder is reduced, the porosity of the positive plate can be improved, and the initial capacity is improved.

Description

Short fiber for lead-acid storage battery plate

Technical Field

The invention relates to the field of lead-acid battery additives, in particular to short fibers for a lead-acid storage battery plate.

Background

The lead-acid storage battery has absolute advantages in chemical power supplies after the lead-acid storage battery is invented. This is because of its low price, easy availability of raw materials, sufficient reliability in use, suitability for large current discharge and wide environmental temperature range, and the like. The lead-acid storage battery is the secondary energy which has the widest application range, the highest safety performance and the highest recyclability in the world at present. Meanwhile, the lead-acid storage battery technology has been developed for years, the problems of specific energy, cycle life, high and low temperature adaptability and the like are broken through, and the short fibers play a significant role in the battery as an important component part in the storage battery plate.

Short fibers with the general length of 1-4mm are added into the lead plaster for preparing the polar plate, and the short fibers are used as a framework for bonding active substances to form a three-dimensional network structure in the polar plate, so that the mechanical strength of the polar plate is enhanced. After the short fibers are added, the lead plaster is easy to form in the plate coating process, and meanwhile, the cracking of the polar plate in the curing and drying process is prevented to a certain extent, and the powder removal of the polar plate in the assembling process is reduced.

Both organic fiber and inorganic fiber can be used for preparing short fiber added in lead plaster of the polar plate, and the organic fiber has higher strength and elastic restoring force than the inorganic fiber, so that the short fiber added in the production process of the current lead-acid storage battery polar plate is organic fiber. Polyester fiber, polypropylene fiber, polyacrylonitrile fiber, modacrylic fiber, polyethylene fiber, polyamide fiber and other organic fibers can be used as short fibers added in the lead paste for preparing the polar plate. The manufacturer can select organic fiber with proper material as short fiber added in the lead plaster for preparing the polar plate according to the actual requirements of acid and alkali resistance, temperature resistance and the like.

Patent No. 201310308516.8 filed by the solar cell group mentions: the short fibers with the same weight adding amount are more, the net distribution structure in the polar plate is good and uniform, and the effects of enhancing the strength of the polar plate, preventing the polar plate from cracking, falling quickly and removing powder are really achieved.

Patent No. 201510545874.X discloses a lead storage battery anode lead paste short fiber which is a polyvinyl acetate short fiber, the length of the short fiber is 2 mm-3 mm, and the single fiber fineness is 1.5D-3D.

However, the polar plate prepared by adding the short fibers still has the problems of low polar plate strength, large harm of floating powder to human bodies and high waste rate in the production process.

Disclosure of Invention

Experimental research shows that: organic short fibers are added into the lead plaster for preparing the polar plate, so that the mechanical strength of the polar plate is enhanced. The reason is that the specific surface area of the short fibers is related to the improvement of the binding power between the active substances, and compared with the larger diameter fibers, the smaller diameter fibers have larger available hydrophilic surface area, and can absorb more water in the preparation process of the polar plate, so that the binding power between the active substances is improved, the mechanical strength of the polar plate is enhanced, and the powder removal of the polar plate is reduced. Not much related to the kind of fiber. The length of the fibers can affect the surface area. The effect increases as the length decreases because a greater number of staple fiber ends are exposed per gram of fiber. But when the length and diameter ratio of the short fibers is too large, the increase is negligible.

It was found that when the short fibers added in the same amount by weight were too thin and the number of short fibers was too large, some short fibers began to be piled and were difficult to be uniformly dispersed, and the active material was affected when it was bonded, and the given battery capacity was rather decreased. Moreover, when the number of short fibers is too large, the fiber volume becomes large, the volume of active substances is occupied, and the volume limit of the frame of the grid is exceeded, so that the strength of the polar plate is reduced.

In order to solve the technical problems, the invention provides a short fiber added into a lead-acid battery pole plate, which can greatly improve the strength of the pole plate and has the effect of 3 times that of the original pole plate; the floating powder is effectively reduced by about 20 percent; waste loss in the production process is reduced; about 25% reduction.

In order to achieve the purpose, the specific technical scheme of the invention is as follows: the short fiber for the lead-acid storage battery pole plate comprises a plurality of organic fibers with the length of less than or equal to 6mm, and the single fiber fineness of the organic fibers is 0.15-0.8D.

Preferably, the single fiber fineness is 0.3-0.6D;

further preferably short fibers with single fiber fineness of 0.35-0.5D;

further, a short fiber having a single fiber fineness of 0.35D is preferable;

the short fiber for the lead-acid storage battery plate is selected from one or more of polyester fiber, polypropylene fiber or polyacrylonitrile fiber;

the fineness deviation ratio of the short fiber is less than or equal to 10 percent.

The invention has the beneficial effects that: by applying the invention, the strength of the polar plate can be greatly improved, and the effect is 3 times of that of the original polar plate; the floating powder is effectively reduced by about 20 percent; waste loss in the production process is reduced; about 25% reduction.

Description of the drawings:

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a graph illustrating the dusting rate of the present invention;

FIG. 3 is a graph illustrating the mass loss rate of the present invention.

In the figure: 1-short fiber.

The specific implementation mode is as follows:

in order to make the technical means, technical features, achievement purposes and effects of the invention easy to understand, the invention is further described with the following embodiments:

the unit of single fiber length is mm (millimeter), the unit of single fiber fineness is D (denier), and denier is the weight in grams of 9000 meters long of fiber at a official moisture regain. Denier is abbreviated as denier (D), e.g., a 9000 meter fiber weighs 1 gram to 1 denier, and the larger the denier, the larger the fiber size, when the fiber density is constant.

The preparation process of the polar plate is as follows:

(1) putting lead powder and short fibers in a mixer, adding sulfuric acid and water, and continuously stirring to form lead plaster suitable for coating a plate;

(2) pressing the combined lead plaster on a grid for coating;

(3) curing and drying; making positive and negative plates.

(4) In the electrolyte of dilute sulfuric acid, a positive plate is connected with a positive electrode of a power supply, a negative plate is connected with a negative plate of the power supply, and a lead paste substance on the positive plate is electrochemically converted into an active substance mainly containing PbO2, and a lead paste substance on the negative plate is converted into an active substance mainly containing spongy lead.

Drop test: the electrode plates of each example and each comparative example are numbered and weighed. The polar plate is parallel to the clean cement ground and freely falls down at the height of 1 m. And repeating the drop test until the polar plate has large-area paste shortage, and stopping the test. And recording the weight change before and after the test, recording the weight change after the test falls for 3 times, 6 times and 9 times, and measuring the test result.

Testing floating powder: taking the polar plates of the examples and the comparative examples, numbering and weighing; and lightly brushing the surface of the polar plate downwards for 5 times from the direction of the polar lug by using a brush, and weighing. The powder flotation rate is the weight difference/initial weight of the plate 100%.

Group 1 to group ratio:

in the short fiber table, 1-1,1-2,1-3 are polyester fibers, 1-4 are polypropylene fibers, 1-5 are polyacrylonitrile fibers, the added mass is 0.1 percent of the total mass of the lead plaster, the length of a single fiber is 3mm, and the fineness of the single fiber is 1.5D. The measurement results were as follows:

group 2 to group ratio:

in the short fiber table, 2-1,2-2,2-3 are polyester fibers, 2-4 are polypropylene fibers, 2-5 are polyacrylonitrile fibers, the added mass is 0.1 percent of the total mass of the lead plaster, the length of a single fiber is 3mm, and the fineness of the single fiber is 1.2D. The measurement results were as follows:

group 3 to group ratio:

in the short fiber table, 3-1,3-2 and 3-3 are polyester fibers, 3-4 are polypropylene fibers and 3-5 are polyacrylonitrile fibers, the added mass is 0.1 percent of the total mass of the lead plaster, the length of a single fiber is 3mm, and the fineness of the single fiber is 1.0D. The measurement results were as follows:

group 1 examples:

in the short fiber table, 4-1,4-2,4-3 are polyester fibers, 4-4 are polypropylene fibers, 4-5 are polyacrylonitrile fibers, the added mass is 0.1 percent of the total mass of the lead plaster, the length of a single fiber is 3mm, and the fineness of the single fiber is 0.8D. The measurement results were as follows:

group 2 examples:

in the short fiber table, 5-1,5-2,5-3 are polyester fibers, 5-4 are polypropylene fibers, 5-5 are polyacrylonitrile fibers, the added mass is 0.1 percent of the total mass of the lead plaster, the length of a single fiber is 3mm, and the fineness of the single fiber is 0.7D. The measurement results were as follows:

group 3 examples:

in the short fiber table, 6-1,6-2,6-3 are polyester fibers, 6-4 are polypropylene fibers, 6-5 are polyacrylonitrile fibers, the added mass is 0.1 percent of the total mass of the lead plaster, the length of a single fiber is 3mm, and the fineness of the single fiber is 0.5D. The measurement results were as follows:

example set 4:

in the short fiber table, 7-1,7-2 and 7-3 are polyester fibers, 7-4 are polypropylene fibers and 7-5 are polyacrylonitrile fibers, the added mass is 0.1 percent of the total mass of the lead paste, the length of a single fiber is 3mm, and the fineness of the single fiber is 0.35D. The measurement results were as follows:

example set 5:

in the short fiber table, 8-1,8-2,8-3 are polyester fibers, 8-4 are polypropylene fibers, 8-5 are polyacrylonitrile fibers, the added mass is 0.1 percent of the total mass of the lead plaster, the length of a single fiber is 3mm, and the fineness of the single fiber is 0.15D. The measurement results were as follows:

the results clearly show that the powder dropping rate and the quality loss rate of 5 groups of examples are greatly better than the technical indexes of 3 comparative examples.

Fig. 2 is a graph in which the fineness is represented by D (denier) and the dusting rate is represented by ten thousandth:

fig. 3 is a graph in which fineness is plotted on the abscissa and the mass loss ratio is plotted on the ordinate, where the unit of fineness is D (denier) and the unit of mass loss ratio is one in ten thousandth:

the two figures clearly show that the powder dropping rate and the quality loss rate of each time of the 5 groups of examples are greatly superior to the technical indexes of the 3 comparative examples, and the obvious peak value appears at the fineness of 0.35D, so that the beneficial effect is optimal.

The strength of the polar plate is also related to the adding proportion of the short fibers, so that the polar plate strength is tested according to different adding proportions under the same fineness of the short fibers.

Example 6, 10 negative green plates are selected optionally, and numbered randomly, the single fiber fineness is selected to be 0.35D, the length is 2-3mm, and the adding proportion accounts for 0.15% of the total mass of the lead plaster. The results are as follows:

comparative example of this example: optionally selecting 10 negative green plates, randomly numbering, selecting 1.5D single fiber fineness and 2-3mm length, wherein the adding proportion is 0.15% of the total mass of the lead plaster. The results are as follows:

the index of example 6 is clearly superior to the comparative example.

Example 7, 5 negative pole cured plates are selected optionally and numbered randomly, the single fiber fineness is selected to be 0.35D, the length is 2-3mm, and the adding proportion accounts for 0.2% of the total mass of the lead plaster. The results are as follows:

example 8: and (3) selecting 10 positive pole cured plates, randomly numbering, selecting 0.5D single fiber fineness and 2-3mm length, wherein the adding proportion accounts for 0.08% of the total mass of the lead plaster. The results are as follows:

comparative example of this example: and (3) selecting 10 positive pole cured plates, randomly numbering, selecting 1.5D single fiber fineness and 2-3mm length, wherein the adding proportion accounts for 0.08% of the total mass of the lead plaster. The results are as follows:

the index of example 8 is clearly superior to the comparative example.

Example 9: optionally selecting 10 positive electrode plates, randomly numbering, selecting single fiber fineness of 0.5D, length of 2-3mm, and adding proportion of 0.05% of the total mass of the lead paste. The results are as follows:

comparative example of this example: optionally selecting 10 positive electrode plates, randomly numbering, selecting 1.5D single fiber fineness and 2-3mm length, wherein the adding proportion is 0.05% of the total mass of the lead plaster. The results are as follows:

the index of example 9 is clearly superior to the comparative example.

Advantageous effects can be obtained in the region of the addition ratio of 0.05 to 0.2.

The polar plate of the lead-acid storage battery is dissected and inspected according to the method disclosed in Chinese patent 201110229425.6, and after the short fibers are separated, the fibers are basically unchanged. The diameter of the electrode plate is measured by related equipment, and is compared with the diameter of the commercial fiber filament made of the same material, so that the fineness of the short fiber in the electrode plate of the lead-acid storage battery can be obtained, and the weight ratio of the short fiber to the active substance of the electrode plate can be obtained.

Although the present invention has been described and illustrated in greater detail by the inventor, it should be understood that modifications and/or alterations to the above-described embodiments, or equivalent alterations thereto, will become apparent to those skilled in the art from this disclosure, without departing from the scope of the invention as defined in the appended claims.

Claims

1. The application of the short fibers in the lead-acid storage battery plate comprises a plurality of organic fibers with the length of 3-6mm, and is characterized in that the single fiber fineness of the organic fibers is 0.15-0.35D, 0.5D and 0.8D.

2. The use of short fibers in a lead-acid battery plate according to claim 1, wherein the organic fibers are one or a mixture of more than one of polyester fibers, polypropylene fibers or polyacrylonitrile fibers.