CN101593835A

CN101593835A - Mercury-free battery zinc powder and manufacturing method thereof

Info

Publication number: CN101593835A
Application number: CNA2009103037327A
Authority: CN
Inventors: 程竹琴
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-06-26
Filing date: 2009-06-26
Publication date: 2009-12-02
Anticipated expiration: 2029-06-26
Also published as: CN101593835B

Abstract

The invention relates to mercury-free battery zinc powder and a manufacturing method thereof. The mercury-free battery zinc powder comprises zinc sheets, wherein the thickness of each zinc sheet is uniform and is 80-250 micrometers, and the volume of each zinc sheet is equivalent to the volume of a spheroid corresponding to a 50-200-mesh sieve. A method for manufacturing mercury-free battery zinc powder, comprising the following steps: A. preparing zinc ingot into zinc powder with granularity of 50-200 meshes; B. screening out granular zinc powder by adopting a sieve; C. heating the screened granular zinc powder to 60-300 ℃, and rolling the granular zinc powder into flat zinc powder, wherein the thickness of the flat zinc powder is required to be 80-250 micrometers; D. the rolled zinc powder is thoroughly mixed with the undersize finer zinc powder. The flat battery zinc powder can save the raw material of the zinc powder for the battery and better meet the electrical property requirement of the battery.

Description

Mercury-free battery zinc powder and manufacturing method thereof

[ technical field ] A

The invention relates to the field of chemical industry, in particular to a negative electrode zinc powder product of a battery, especially an alkaline zinc-manganese battery, taking zinc powder as an active substance and production.

[ background of the invention ]

Most of the zinc powder used for the traditional battery is produced by an atomization method, the particle size of the zinc powder is different between 40 and 200 meshes, and the particle appearance is irregular. After the battery is made, the reaction rates of zinc powder particles are different, and the reaction speed is fast or slow; and the shape change of the particles after the zinc powder reacts is uncontrollable, so that some zinc powder can react completely early, and some zinc powder can not be completely reacted even if long time is needed. Therefore, it cannot be completely reacted to cause waste of the zinc powder raw material.

Most of the existing mercury-free battery zinc powder is produced by adopting a gas atomization method, and the produced mercury-free battery zinc powder product is also basically spherical particles. The time for completely reacting the particles with different diameters is short, the particles are completely reacted within a few minutes quickly, and the particles of the zinc powder are too large to completely react. In the case of alkaline zinc-manganese cells, about 10-20% of the zinc powder in each cell is not completely reacted, and some zinc powder is not reacted even up to about 30%. This results in a great waste of raw materials.

The existing 'sphere-like' particle mercury-free battery zinc powder product has defects in large-current discharge performance. The main reason is that the specific surface area of the 'sphere-like' zinc powder is small, and if the zinc powder is made fine, excessive gassing can be caused.

The zinc anode of patent application No. 97192179.2 has the following characteristics: the zinc density is less than 6.5g/cc; is a zinc flake having thickness, length and width dimensions, the thickness dimension being at least 10 times less than its length and width dimensions; the zinc anode may also contain zinc powder.

Patent application No. 97192179.2 entitled "zinc anode for electrochemical cells" relates to an electrochemical cell comprising a zinc or zinc alloy sheet and the zinc anode of this patent solves the problem of: a zinc anode is provided which is capable of significantly reducing the amount of zinc applied to a mercury-free anode while maintaining a sufficient current-carrying matrix while maintaining good electrical conductivity, improving high discharge efficiency, and solving the problems of shock and vibration sensitivity. In the patent, the thickness of the zinc sheets is too thin, so that good conductivity is maintained and discharge efficiency is improved, but the thickness among the zinc sheets is uneven, or the diameter ratio of the zinc sheets to the zinc particles is not appropriate, so that partial zinc particles or zinc sheets are remained, but the satisfactory discharge efficiency is difficult to provide, and the zinc powder cannot be fully and completely utilized.

In the prior art, the diameters of zinc particles are different, the reaction rates are different, and when more large-particle zinc powder is left, the anode is difficult to provide discharge efficiency meeting the requirement, so that the zinc powder cannot be fully and completely utilized.

The application provides a flat battery zinc powder aiming at the situation that the time for completely reacting zinc powder particles with different diameters in an anode is short, the reaction is complete within a few minutes, and the complete reaction is impossible if some zinc powder particles are too large, so that the zinc powder can save the zinc powder raw material for the battery and better meet the electrical property requirement of the battery.

[ summary of the invention ]

The invention provides mercury-free zinc powder for a battery and a manufacturing method thereof, aiming at saving the raw material of the zinc powder for the battery and better meeting the electrical property requirement of the battery.

The mercury-free battery zinc powder comprises zinc sheets, wherein the thickness of each zinc sheet is uniform and is 80-250 micrometers, and the volume of each zinc sheet is equivalent to the volume of a spheroid corresponding to a 50-200-mesh sieve.

The preferred technical scheme of the invention is as follows: the thickness of the zinc sheet is uniform and is between 80 and 100 micrometers.

The preferred technical scheme of the invention is as follows: the thickness of the zinc sheet is uniform and is between 100 and 154 microns.

The preferred technical scheme of the invention is as follows: the thickness of the zinc sheet is uniform and is between 154 and 250 micrometers.

The preferred technical scheme of the invention is as follows: the battery zinc powder also comprises zinc particles, and the diameter of each zinc particle is smaller than or equal to the thickness of the zinc sheet.

The preferred technical scheme of the invention is as follows: the offset distance from any point of the surface of the single zinc sheet to the reference surface is less than or equal to 10 microns. The surface of a part subjected to mechanical processing always has some geometric errors on the macro and the micro, the geometric errors on the micro on the surface of the part are formed by a series of peaks and valleys with tiny intervals on the surface of the part, and the fluctuation degree of the heights of the tiny peaks and valleys is called the surface roughness of the part. The surface roughness of the zinc sheet of the invention is strict, and the difference of the single zinc sheet is 10 micrometers, namely the difference of the highest point and the lowest point on the same surface of the single zinc sheet is 10 micrometers.

A method for manufacturing mercury-free battery zinc powder, comprising the following steps:

A. preparing zinc ingot into zinc powder with granularity of 50-200 meshes;

B. heating the screened granular zinc powder to 60-300 ℃, and rolling the granular zinc powder into flat zinc powder, wherein the thickness of the flat zinc powder is required to be 80-250 micrometers; the screened granular zinc powder refers to any granules with the granularity of more than 200 meshes and less than 50 meshes.

The preferable technical scheme of the method is as follows:

A. preparing zinc ingot into zinc powder with granularity of 50-200 meshes;

B. screening out granular zinc powder by adopting a sieve; the screened granular zinc powder refers to any granules with the granularity of more than 150 meshes and less than 50 meshes.

C. Heating the screened granular zinc powder to 60-300 ℃, and rolling the granular zinc powder into flat zinc powder, wherein the thickness of the flat zinc powder is required to be 80-250 microns;

D. the rolled zinc powder is thoroughly mixed with the undersize finer zinc powder.

The preferred technical scheme of the method is as follows: the screened granular zinc powder refers to any granules with the granularity of more than or equal to 100 meshes and less than 50 meshes.

"mesh" means the number of openings made in the screen surface over a length of 25.4mm (1 inch). If 30 holes are formed, the sieve is weighed as a 30-mesh sieve, and the size of the hole diameter is 25.4mm/30 minus the diameter of the sieve rope.

The flat zinc powder can not generate the change of particle morphology in the discharge reaction process, and the time difference of full reaction is not much. The zinc powder electrode can be completely reacted under the condition of ensuring that the electrolyte is sufficient, and the waste of the zinc powder can not be generated.

The flat zinc powder has a large specific surface area, and the zinc powder is easy to fully contact with electrolyte, so that the battery can completely meet the requirements of large-current and high-power discharge. The discharge performance of the battery is effectively improved.

To sum up: the flat battery zinc powder can save the raw material of the zinc powder for the battery and better meet the electrical property requirement of the battery.

[ detailed description ] A

The following specific embodiments may further illustrate the invention:

the first embodiment is as follows:

screening 50-200 meshes of zinc powder into two parts of more than 154 mu m and less than 154 mu m by a 100-mesh sieve, rolling the part of more than 154 mu m into flat zinc powder with the thickness of 154 mu m, mixing the flat zinc powder with the part of less than 154 mu m, filling the mixture into a No. 5 alkaline manganese battery under the same condition, and dissecting the battery after discharging, wherein the zinc powder has completely reacted. The above tests all produced different degrees of residue with non-present zinc powders (under equivalent conditions).

Example two:

sieving 50-200 meshes of zinc powder into two parts of more than 100 mu m and less than 100 mu m by a 140-mesh sieve, rolling the part of more than 100 mu m into flat zinc powder with the thickness of 100 mu m, mixing the flat zinc powder with the part of less than 100 mu m, filling the mixture into a large-size alkaline manganese battery under the same condition, and dissecting the battery after discharging, wherein the zinc powder completely reacts. The above trial study produced varying degrees of residue with non-base zinc powders (under equivalent conditions), and the present modified zinc powders of 100 μm size had reacted to completion.

The foregoing is a more detailed description of the present invention in connection with specific preferred embodiments thereof, and it is not intended that the practice of the invention be limited to these descriptions. For those skilled in the art to which the invention pertains, numerous simple deductions or substitutions may be made without departing from the spirit of the invention, which shall be deemed to belong to the scope of the invention.

Claims

1. The mercury-free battery zinc powder contains zinc sheets and is characterized in that: the thickness of the zinc sheet is uniform and between 80 and 250 micrometers, and the volume of the zinc sheet is equivalent to the volume of a spheroid corresponding to a 50 to 200-mesh sieve.

2. The mercury-free battery zinc powder as defined in claim 1, wherein: the thickness of the zinc sheet is uniform and is between 80 and 100 micrometers.

3. The mercury-free battery zinc powder as defined in claim 1, wherein: the thickness of the zinc sheet is uniform and is between 100 and 154 microns.

4. Mercury-free battery zinc powder according to claim 1, characterized in that: the thickness of the zinc sheet is uniform and is between 154 and 250 micrometers.

5. Mercury-free battery zinc powder according to any one of claims 1 to 4, characterized in that: the battery zinc powder also comprises zinc particles, and the diameter of each zinc particle is smaller than or equal to the thickness of the zinc sheet.

6. Mercury-free battery zinc powder according to any one of claims 1 to 4, characterized in that: and the offset distance from any point on the surface of the single zinc sheet to the reference surface is less than or equal to 10 micrometers.

7. The mercury-free battery zinc powder as defined in claim 5, wherein: the offset distance from any point of the surface of the single zinc sheet to the reference surface is less than or equal to 10 microns.

8. The method for manufacturing the mercury-free battery zinc powder is characterized by comprising the following steps: comprises the following steps:

A. preparing zinc ingot into zinc powder with granularity of 50-200 meshes;

B. heating the screened granular zinc powder to 60-300 ℃, and rolling the granular zinc powder into flat zinc powder, wherein the thickness of the flat zinc powder is required to be 80-250 microns; the screened granular zinc powder refers to any granules with the granularity of more than 200 meshes and less than 50 meshes.

9. The method for manufacturing mercury-free battery zinc powder as defined in claim 8, wherein:

A. preparing zinc ingot into zinc powder with granularity of 50-200 meshes;

10. The method according to any one of claims 8 or 9, wherein: the screened granular zinc powder refers to any granules with the granularity of more than or equal to 100 meshes and less than 50 meshes.