CN118693278A - A conductive material for alkaline zinc-manganese battery and application method - Google Patents

Abstract

The invention discloses an alkaline zinc-manganese battery conductive material and an application method, belonging to the field of batteries. The preparation method of the alkaline zinc-manganese battery conductive material comprises the following steps: (1) mixing manganese dioxide powder with a purity of more than 99.9%, acetylene black and a binder in a certain proportion and stirring; (2) pressing the mixed material in step (1) into shape; (3) slicing the positive electrode sheet pressed in step (2) to obtain a positive electrode sheet of a certain size; (4) placing the positive electrode sheet in step (3) into an oven for drying to obtain the alkaline zinc-manganese battery conductive material; (5) post-processing and testing the alkaline zinc-manganese battery conductive material. The alkaline zinc-manganese battery conductive material prepared by the invention has a large capacity retention rate, strong corrosion resistance, large tensile strength, excellent conductivity, and broad application prospects.

Description

A conductive material for alkaline zinc-manganese battery and application method

Technical Field

The invention belongs to the field of alkaline zinc-manganese battery conductive materials, and in particular relates to an alkaline zinc-manganese battery conductive material and an application method.

Background Art

Alkaline zinc-manganese battery uses manganese dioxide as the positive electrode, zinc as the negative electrode, and a high concentration of alkaline solution as the electrolyte. In this battery, the choice of conductive materials directly affects the performance and life of the battery. In terms of the positive electrode, manganese dioxide is not only an active substance, but also a conductive material. The crystal structure of manganese dioxide makes it electronically conductive, and its porous nature facilitates the migration of electrolyte ions. In order to improve the high conductivity, graphite or other carbon materials are usually added to manganese dioxide. These mixed conductive agents can enhance the electron transmission capacity of the electrode; the pure zinc in the negative electrode has a certain conductivity. In the production of time, a small amount of other metals such as aluminum and lead are often added as alloying elements to improve the mechanical strength and corrosion resistance of the zinc electrode; the electrolyte part usually uses a strong base such as potassium hydroxide, which not only provides a good ionic conductive environment, but also participates in the electrochemical reaction. The high ionic conductivity of this electrolyte ensures the effective movement of electrons and ions inside the battery, thereby ensuring the stable discharge of the battery. Alkaline zinc-manganese batteries are widely used in various portable electronic devices, such as remote controls, wireless mice, flashlights, and a variety of children's toys, because they are low-cost, easy to carry, and can be used without charging. Due to their good voltage stability and relatively high energy density, they are also often used in devices that require a certain power output, such as some communication equipment and outdoor sports equipment. Due to their good safety and not prone to leakage or corrosion, alkaline zinc-manganese batteries have become one of the preferred power sources for first aid equipment, smoke alarms, and anti-theft equipment.

However, during the preparation process of traditional alkaline zinc-manganese batteries, a large amount of harmful substances such as heavy metals will be produced, which will cause environmental pollution if not handled properly. Secondly, the traditional preparation process often has high energy consumption, which is not conducive to emission reduction and sustainable development. Traditional conductive materials may have performance degradation problems during the use of the battery, such as decreased conductivity, increased resistance, etc., which will affect the battery's service life and performance stability. Therefore, in order to improve the conductive performance of alkaline zinc-manganese batteries, the following methods are often adopted: nano-conductive materials, introduction of carbon materials, design of three-dimensional porous structures, optimization of electrolytes and manganese dioxide surface modification, etc.

At present, one of the ideas for improving the conductivity of alkaline zinc-manganese batteries is to introduce carbon materials. Carbon materials with high conductivity, such as carbon nanotubes and graphene, are compounded with manganese dioxide to form conductive composite materials. These carbon materials can form a conductive network between manganese dioxide particles to improve the overall conductivity of the battery. The introduction of carbon materials not only improves the conductivity, but also helps to improve the cycle stability and rapid charge and discharge performance of the battery.

Chinese invention patent application CN104882570B discloses a steel shell of an alkaline zinc-manganese battery and an alkaline zinc-manganese battery, which involves coating the inner wall of the current collector steel shell with a graphene-modified conductive coating to improve the coverage density and bonding performance of the conductive coating and the inner surface of the steel shell, thereby reducing the radial resistance of the battery and the interface resistance between the positive electrode ring and the steel shell, thereby improving the high current discharge performance of the alkaline zinc-manganese battery. Among them, when the thickness of the graphene material is 10nm, the specific surface area is ^2500m2 /g, and the area is 0.01 micron, 49wt% graphene, 50wt% carbon black, 1wt% CMC binder and a small amount of sodium dodecyl sulfate are uniformly dispersed in water to obtain a mixed slurry, and then the slurry is sprayed on the inner wall of the steel shell, and after drying, a graphene-modified conductive coating is obtained. At this time, the graphene-modified coating loading of the steel shell is 0.6mg/piece, the thickness of the conductive coating is 1 micron, and the short-circuit current is 30A; when the thickness of the graphene material is 100nm, the specific surface area is ^10m2 /g, the area is 10 microns, 98wt% graphene, 1wt% acetylene black, 1wt% polyvinylidene fluoride binder and a small amount of sodium dodecyl sulfate are uniformly dispersed in water to obtain a mixed slurry, and then the slurry is sprayed on the inner wall of the steel shell, and after drying, a graphene-modified conductive coating is obtained, the thickness of the conductive coating is 20 microns, and the short-circuit current at this time is 32A; when the thickness of the graphene material is 0.5nm, the specific surface area is ^1250m2 /g, and the area is 1000 microns, 1wt% graphene, 98wt% graphite, 10wt% SBR binder and a small amount of sodium dodecyl sulfate are uniformly dispersed in water to obtain a mixed slurry, and then the slurry is sprayed on the inner wall of the steel shell, and after drying, a graphene-modified conductive coating is obtained, the thickness of the conductive coating is 0.01 micron, and the short-circuit current at this time is 35A. It can be seen that the higher the coverage density of the graphene coating on the steel shell, the stronger the conductivity. However, experimental data show that the battery capacity is reduced at this time. This may be because, in the battery, the electrolyte is the medium for ion transmission, and the electrode material is the main body for storing and releasing energy. When the conductivity of the battery is enhanced, it means that electrons can flow from the negative electrode to the positive electrode more quickly through the external circuit. But at the same time, if the improvement of the electrolyte or electrode material sacrifices its energy storage capacity, even if the electrons flow faster, the total available energy is decreasing, which is manifested as a decrease in battery capacity. In some emergency start-up equipment or high-power short-term use equipment, a large amount of current needs to be released quickly to drive the equipment to operate. For equipment with long-term stable power supply, such as some remote monitoring equipment, smart wearable devices, etc., the reduction in battery capacity will directly affect the battery life of the equipment, which is very unfavorable in practical applications.

Therefore, in order to obtain alkaline zinc-manganese battery conductive materials with strong conductivity without reducing the battery capacity, it is necessary to conduct in-depth research on them, especially to optimize the selection and dosage of raw materials, so as to avoid the conductive properties and battery capacity of alkaline zinc-manganese battery conductive materials failing to meet expectations due to different raw materials and dosages.

Summary of the invention

1. Problem to be solved

In view of the problem in the prior art that the conductive properties of alkaline zinc-manganese battery conductive materials are enhanced but the battery capacity is reduced, the present invention uses manganese dioxide powder, acetylene black and adhesive as main raw materials to prepare an alkaline zinc-manganese battery conductive material, and provides an application method of the alkaline zinc-manganese battery conductive material to achieve high conductivity and high battery capacity of the alkaline zinc-manganese battery conductive material.

2. Technical solution

In order to solve the above problems, the technical solution adopted by the present invention is as follows:

The present invention provides an alkaline zinc-manganese battery conductive material, and the preparation method of the alkaline zinc-manganese battery conductive material comprises the following steps:

(1) Mixing manganese dioxide powder with a purity of more than 99.9%, acetylene black and a binder in a certain proportion and stirring; the acetylene black in this step has a small specific gravity, fine particles and good conductivity, and can effectively improve the conductivity of the positive electrode sheet; the binder in this step is polytetrafluoroethylene, which has good adhesion and chemical stability, and can effectively combine the conductive material and manganese dioxide powder tightly together;

(2) pressing the mixed material in step (1) into a mold;

(3) Slicing the positive electrode sheet pressed in step (2) to obtain a positive electrode sheet of a certain size;

(4) placing the positive electrode sheet in step (3) in an oven for drying to obtain an alkaline zinc-manganese battery conductive material; the purpose of drying in this step is to remove moisture and volatiles therein and improve the stability and conductive performance of the positive electrode sheet;

(5) Post-processing and testing of conductive materials for alkaline zinc-manganese batteries; in this step, the dried positive electrode sheet is surface treated and coated with a thin layer of silver powder to improve conductivity and corrosion resistance; in this step, the prepared positive electrode sheet is quality tested, including conductivity testing, porosity testing, thickness and size measurement, etc., to ensure that the positive electrode sheet meets the requirements of alkaline zinc-manganese batteries.

As a further improvement of the present invention, the manganese dioxide powder in step (1) needs to be sieved first to remove large particles and impurities therein to ensure that the particle size distribution of the powder is uniform and the average particle size is between 1-5 microns.

As a further improvement of the present invention, in the step (1), the ratio of manganese dioxide powder, acetylene black and adhesive is 85:10:5.

As a further improvement of the present invention, the purity of acetylene black in step (1) reaches above 99.9%.

As a further improvement of the present invention, the mixture in step (1) is mixed using a high-speed stirrer, and the stirring time is controlled within 30 minutes to ensure that various materials are fully and evenly mixed.

As a further improvement of the present invention, in step (2), the temperature of the calender is controlled to be 100-200° C. and the pressure is controlled to be 10-30 MPa to ensure that the porosity of the positive electrode sheet is between 30% and 50% to facilitate electrolyte penetration and ion transport.

As a further improvement of the present invention, in the step (4), the drying temperature is controlled at 80-100° C. and the drying time is about 2 hours.

As a further improvement of the present invention, the present invention provides an application method of an alkaline zinc-manganese battery conductive material, comprising the following steps:

(a) Preparation of positive electrode sheet: manganese dioxide powder with a purity of more than 99.9%, a conductive agent and a binder are mixed in a certain proportion, formed into a structure with a certain porosity by a calendering method, and then subjected to a constant temperature drying treatment;

(b) Preparation of negative electrode sheet: zinc powder and silver powder with a purity of more than 99.9% are mixed in a certain proportion, rolled into a thin sheet, and then heat treated and cured;

(c) stacking the positive electrode, the negative electrode and the isolation layer in sequence;

(d) inserting the prepared electrode assembly into the battery case and injecting the prepared potassium hydroxide solution as electrolyte;

(e) performing sealing treatment;

As a further improvement of the present invention, the adhesive in step (a) is polyvinylidene fluoride.

As a further improvement of the present invention, the preset ratio in step (a) is that the mass ratio of manganese dioxide powder to conductive agent is 9:1, and the added amount of binder is between 5% and 10%.

As a further improvement of the present invention, the mixing method in step (a) adopts ultrasonic dispersion technology.

As a further improvement of the present invention, the calendering method in step (a) adopts a double-roll calender.

As a further improvement of the present invention, the porosity in step (a) is maintained between 25% and 40%.

As a further improvement of the present invention, the constant temperature drying condition in step (a) is that the temperature is controlled between 80-120° C. and the time is set to 12-24 hours.

As a further improvement of the present invention, the mass ratio of zinc powder to silver powder in step (b) is 100:1-200:1, and the mixing method of zinc powder and silver powder in step (b) is mixing in a ball mill.

As a further improvement of the present invention, the calendering parameters in the step (b) are set to a pressure of 5-10 MPa, a thickness of the sheet is 0.2 mm±0.02 mm, and a temperature of the heat treatment is between 60-80°C.

As a further improvement of the present invention, the isolation layer in step (c) is a microporous structure formed by extruding high-density polyethylene at 150-200° C. and passing through a mold, stretching and heat treatment.

As a further improvement of the present invention, the concentration of the potassium hydroxide solution in step (d) is 10-12 mol/L.

As a further improvement of the present invention, the range of the rolling pressure parameter setting in the step (b) is based on the ground-air intelligent adaptive weighted fuzzy clustering algorithm, and the expression of the ground-air intelligent adaptive weighted fuzzy clustering algorithm is:

In formula (1), y is the calendering pressure parameter setting, h _mn is the Euclidean distance between raw materials m and raw materials n, h _cj is the Euclidean distance between raw materials c and raw materials j, m is the ordinal number of raw material m, n is the ordinal number of raw material n, c is the ordinal number of raw material c, and j is the ordinal number of raw material j, where c, j < m, n, f, B and q are constants, when the values of f and B are < m, y takes the minimum value, and when q is greater than n, y takes the maximum value;

In formula (2), α is the ordinal number of the raw material, m.lat is the latitude of the raw material m, m ² .lat is the square of the latitude of the raw material m, m.lng is the longitude of the raw material m, and m ² .lng is the square of the longitude of the raw material m;

In formula (3), β is the ordinal number of the raw material, c.lat is the latitude of the raw material m, sm ² .lat is the square of the latitude of the raw material m, m.lng is the longitude of the raw material m, and m ² .lng is the square of the longitude of the raw material m;

Δy＝Rarccos[cos ² Δh+sin ² Δh] (4)

In formula (4), Δy is the difference in pressure parameter settings, Δh is the absolute value of the difference between h _mn and h _cj , and Rarc is the inverse trigonometric function;

Δh＝|h _mn -h _cj | (5)

In formula (5), h _mn is the Euclidean distance between raw material m and raw material n, and h _cj is the Euclidean distance between raw material c and raw material j.

3. Beneficial effects

Compared with the prior art, the present invention has the following beneficial effects:

(1) The alkaline zinc-manganese battery conductive material prepared by the present invention uses manganese dioxide with a purity of more than 99.9% as the basic raw material, which ensures that the final product has excellent chemical activity and stability. In the mixing step, fine particles of acetylene black are added, which has a small specific gravity and good conductive properties, so that the conductive performance of the positive electrode is significantly improved. Experimental data show that the conductivity of the positive electrode made of this mixed material is about 20% higher than that of the traditional pure manganese dioxide material.

(2) The alkaline zinc-manganese battery conductive material prepared by the present invention uses polytetrafluoroethylene as a binder. The adhesion and chemical stability of polytetrafluoroethylene ensure the close bonding between manganese dioxide and acetylene black. Experimental tests show that when polytetrafluoroethylene binder is used as the positive electrode material, its peel strength is more than 30% higher than that of other types of binders, thereby greatly enhancing the cycle stability and service life of the battery.

(3) The alkaline zinc-manganese battery conductive material prepared by the present invention can precisely control the consistency of size and thickness during the pressing and subsequent slicing process, laying the foundation for the production of standardized and unified battery components. The moisture and volatile substances of these precisely processed positive electrode sheets are effectively removed in the subsequent oven drying step, further improving the stability and conductivity of the material. The data show that the stability of the positive electrode sheets after drying is improved by at least 15%.

(4) The alkaline zinc-manganese battery conductive material prepared by the present invention not only improves the conductivity but also enhances the corrosion resistance by coating a thin layer of silver powder on the surface of the positive electrode material. After quality inspection, the qualified rate of the positive electrode sheet reaches more than 98%, which is much higher than the industry average.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of an alkaline zinc-manganese battery of the present invention.

DETAILED DESCRIPTION

The present invention is further described below in conjunction with specific embodiments.

Example 1

This embodiment is a preparation process of an alkaline zinc-manganese battery conductive material, comprising the following steps:

1) weighing 100 g of manganese dioxide powder with a purity of 99.9% with an analytical balance, sieving with a high-precision airflow classifier, setting the airflow velocity between 13-16 m/s, and setting the dispersion disk speed between 300-400 rpm to obtain a manganese dioxide powder with an average particle size between 1-5 microns, and then weighing 85 g of the sieved manganese dioxide powder, 10 g of acetylene black with a purity of more than 99.9% and 5 g of polytetrafluoroethylene with an analytical balance, and mixing them with a high-speed stirrer for 30 minutes, and setting the speed of the high-speed stirrer to between 1000-2000 rpm;

2) controlling the temperature of the calender to be 90-110° C. and the pressure to be between 10-20 MPa, and pressing the material mixed in step 1) through the calender to form a positive electrode sheet having an actual density close to 85%-90% of the theoretical density, a porosity of 30%-50% and a thickness of 150 μm;

3) The positive electrode sheet in step 2) was cut into cylindrical shapes with a diameter of 18 mm and a thickness of 150 μm, and dried in an oven at 80-100° C. for 2 hours.

The following tests were performed for Example 1:

(1) XRD analysis: Prepare the final product sample, place it on the XRD sample stage, set the XRD scanning range to 5-80°, the step length to 0.05°, and the scanning speed to 0.5 s/step, start scanning and record the diffraction data, and compare the obtained diffraction pattern with the standard card to confirm the crystal structure.

(2) SEM analysis: The sample was fixed on the SEM sample stage and subjected to conductive treatment. The magnification of the SEM was set to 5000 times and the working distance was between 5 and 10 mm to obtain the particle size distribution data of the material.

According to the tests of (1)-(2) above, the results are recorded in Table 1:

Table 1 Example 1 Test results statistics

It can be seen from the data in Table 1 that the XRD analysis and SEM analysis of the alkaline zinc-manganese battery conductive material of Example 1 are consistent with the standard card comparison.

Comparative Example 1

This comparative example is basically the same as Example 1, except that the mass of the sieved manganese dioxide powder is 90 g, the mass of acetylene black with a purity of more than 99.9% is 5 g, and the mass of polytetrafluoroethylene is 5 g.

The following tests were performed for Comparative Example 1:

(1) XRD analysis: Prepare the final product sample, place it on the XRD sample stage, set the XRD scanning range to 5-80°, the step length to 0.05°, and the scanning speed to 0.5 s/step, start scanning and record the diffraction data, and compare the obtained diffraction pattern with the standard card to confirm the crystal structure.

(2) SEM analysis: The sample was fixed on the SEM sample stage and subjected to conductive treatment. The magnification of the SEM was set to 5000 times and the working distance was between 5 and 10 mm to obtain the particle size distribution data of the material.

According to the tests of (1)-(2) above, the results are recorded in Table 2:

Table 2 Comparative Example 1 Test Results Statistics

It can be seen from the data in Table 2 that the XRD analysis and SEM analysis of the alkaline zinc-manganese battery conductive material of Comparative Example 1 are consistent with those of the standard card.

Comparative Example 2

This comparative example is basically the same as Example 1, except that the mass of the sieved manganese dioxide powder is 80 g, the mass of acetylene black with a purity of more than 99.9% is 15 g, and the mass of polytetrafluoroethylene is 5 g.

The following tests were performed for Comparative Example 2:

(1) XRD analysis: Prepare the final product sample, place it on the XRD sample stage, set the XRD scanning range to 5-80°, the step length to 0.05°, and the scanning speed to 0.5 s/step, start scanning and record the diffraction data, and compare the obtained diffraction pattern with the standard card to confirm the crystal structure.

(2) SEM analysis: The sample was fixed on the SEM sample stage and subjected to conductive treatment. The magnification of the SEM was set to 5000 times and the working distance was between 5 and 10 mm to obtain the particle size distribution data of the material.

According to the tests of (1)-(2) above, the results are recorded in Table 3:

Table 3 Comparative Example 2 Test Results Statistics

It can be seen from the data in Table 3 that the XRD analysis and SEM analysis of the alkaline zinc-manganese battery conductive material of Comparative Example 2 are consistent with those of the standard card.

Example 2

The "four-probe resistance method" is used to test the resistivity of the positive electrode sheet to be tested using a current source, a voltmeter, a four-probe resistance measuring device and a positive electrode sheet to be tested, so as to evaluate its conductivity. The three positive electrode sheets to be tested are respectively referred to as Example 1, Comparative Example 1 and Comparative Example 2, and the operating steps are as follows:

1) Place the positive electrode to be tested on the four-probe resistance measurement device to ensure that the positive electrode to be tested is in good contact with the probes;

2) Turn on the current source and adjust the current to the preset value of 1mA;

3) Read the reading on the voltmeter and record it;

4) Calculate the resistivity according to Ohm’s law;

5) Result analysis: all data are recorded in Table 4.

Table 4 Conductivity test results statistics

Group Current (mA) Voltage (V) Resistivity (Ω·m) Example 1 1 0.01 10 Comparative Example 1 1 0.015 15 Comparative Example 2 1 0.012 12

Through the above test, it can be seen from Table 4 that when the current is the same, within a certain range, the resistivity changes with the change of the mass ratio of the sieved manganese dioxide powder, acetylene black with a purity of more than 99.9% and polytetrafluoroethylene. Example 1 has the smallest voltage and the smallest resistivity, that is, when the mass ratio of the sieved manganese dioxide powder, acetylene black with a purity of more than 99.9% and polytetrafluoroethylene is 85:10:5, the resistivity of the prepared alkaline zinc-manganese battery conductive material is the smallest.

Example 3

This embodiment is a preparation process of an alkaline zinc-manganese battery conductive material, comprising the following steps:

1) 100 g of manganese dioxide powder with a purity of 99.9% was weighed on an analytical balance, and sieved using a high-precision airflow classifier, with the airflow velocity set between 13-16 m/s and the dispersion disk speed set to 300 rpm to obtain manganese dioxide powder with an average particle size of 4 microns, and then 85 g of the sieved manganese dioxide powder, 10 g of acetylene black with a purity of more than 99.9% and 5 g of polytetrafluoroethylene were weighed on an analytical balance, and mixed for 30 minutes using a high-speed stirrer, with the speed of the high-speed stirrer set to 1000 rpm;

2) controlling the temperature of the calender to be 90-110° C. and the pressure to be between 10-20 MPa, and pressing the material mixed in step 1) through the calender to form a positive electrode sheet having an actual density close to 85%-90% of the theoretical density, a porosity of 30%-50% and a thickness of 150 μm;

3) The positive electrode sheet in step 2) was cut into cylindrical shapes with a diameter of 18 mm and a thickness of 150 μm, and dried in an oven at 80-100° C. for 2 hours.

The following tests were performed for Example 3:

(1) XRD analysis: Prepare the final product sample, place it on the XRD sample stage, set the XRD scanning range to 5-80°, the step length to 0.05°, and the scanning speed to 0.5 s/step, start scanning and record the diffraction data, and compare the obtained diffraction pattern with the standard card to confirm the crystal structure.

(2) SEM analysis: The sample was fixed on the SEM sample stage and subjected to conductive treatment. The magnification of the SEM was set to 5000 times and the working distance was between 5 and 10 mm to obtain the particle size distribution data of the material.

According to the tests of (1)-(2) above, the results are recorded in Table 5:

Table 5 Example 3 test results statistics

It can be seen from the data in Table 5 that the XRD analysis and SEM analysis of the alkaline zinc-manganese battery conductive material of Example 3 are consistent with the standard card comparison.

Example 4

This embodiment is a preparation process of an alkaline zinc-manganese battery conductive material, comprising the following steps:

1) 100 g of manganese dioxide powder with a purity of 99.9% was weighed on an analytical balance, and sieved with a high-precision airflow classifier, with the airflow velocity set between 13-16 m/s and the dispersion disk speed set to 350 rpm to obtain manganese dioxide powder with an average particle size of 4 microns, and then 85 g of the sieved manganese dioxide powder, 10 g of acetylene black with a purity of more than 99.9% and 5 g of polytetrafluoroethylene were weighed on an analytical balance, and mixed with a high-speed stirrer for 30 minutes, and the speed of the high-speed stirrer was set to 1000 rpm;

2) controlling the temperature of the calender to be 90-110° C. and the pressure to be between 10-20 MPa, and pressing the material mixed in step 1) through the calender to form a positive electrode sheet having an actual density close to 85%-90% of the theoretical density, a porosity of 30%-50% and a thickness of 150 μm;

3) The positive electrode sheet in step 2) was cut into cylindrical shapes with a diameter of 18 mm and a thickness of 150 μm, and dried in an oven at 80-100° C. for 2 hours.

The following tests were performed for Example 4:

(1) XRD analysis: Prepare the final product sample, place it on the XRD sample stage, set the XRD scanning range to 5-80°, the step length to 0.05°, and the scanning speed to 0.5 s/step, start scanning and record the diffraction data, and compare the obtained diffraction pattern with the standard card to confirm the crystal structure.

(2) SEM analysis: The sample was fixed on the SEM sample stage and subjected to conductive treatment. The magnification of the SEM was set to 5000 times and the working distance was between 5 and 10 mm to obtain the particle size distribution data of the material.

According to the tests of (1)-(2) above, the results are recorded in Table 6:

Table 6 Statistical table of test results of Example 4

It can be seen from the data in Table 6 that the XRD analysis and SEM analysis of the alkaline zinc-manganese battery conductive material of Example 3 are consistent with the standard card comparison.

Example 5

This embodiment is a preparation process of an alkaline zinc-manganese battery conductive material, comprising the following steps:

1) 100 g of manganese dioxide powder with a purity of 99.9% was weighed on an analytical balance, and sieved with a high-precision airflow classifier, with the airflow velocity set between 13-16 m/s and the dispersion disk speed set to 400 rpm to obtain manganese dioxide powder with an average particle size of 4 microns, and then 85 g of the sieved manganese dioxide powder, 10 g of acetylene black with a purity of more than 99.9% and 5 g of polytetrafluoroethylene were weighed on an analytical balance, and mixed with a high-speed stirrer for 30 minutes, and the speed of the high-speed stirrer was set to 1000 rpm;

2) controlling the temperature of the calender to be 90-110° C. and the pressure to be between 10-20 MPa, and pressing the material mixed in step 1) through the calender to form a positive electrode sheet having an actual density close to 85%-90% of the theoretical density, a porosity of 30%-50% and a thickness of 150 μm;

3) The positive electrode sheet in step 2) was cut into cylindrical shapes with a diameter of 18 mm and a thickness of 150 μm, and dried in an oven at 80-100° C. for 2 hours.

The following tests were performed for Example 5:

(1) XRD analysis: Prepare the final product sample, place it on the XRD sample stage, set the XRD scanning range to 5-80°, the step length to 0.05°, and the scanning speed to 0.5 s/step, start scanning and record the diffraction data, and compare the obtained diffraction pattern with the standard card to confirm the crystal structure.

(2) SEM analysis: The sample was fixed on the SEM sample stage and subjected to conductive treatment. The magnification of the SEM was set to 5000 times and the working distance was between 5 and 10 mm to obtain the particle size distribution data of the material.

According to the tests of (1)-(2) above, the results are recorded in Table 7:

Table 7 Example 5 Test Results Statistics

It can be seen from the data in Table 7 that the XRD analysis and SEM analysis of the alkaline zinc-manganese battery conductive material of Example 5 are consistent with the standard card comparison.

Example 6

This embodiment is a preparation process of an alkaline zinc-manganese battery conductive material, comprising the following steps:

1) 100 g of manganese dioxide powder with a purity of 99.9% was weighed on an analytical balance, and sieved using a high-precision airflow classifier, with the airflow velocity set between 13-16 m/s and the dispersion disk speed set to 300 rpm to obtain a manganese dioxide powder with an average particle size of 4 microns, and then 85 g of the sieved manganese dioxide powder, 10 g of acetylene black with a purity of more than 99.9% and 5 g of polytetrafluoroethylene were weighed on an analytical balance, and mixed for 30 minutes using a high-speed stirrer, with the speed of the high-speed stirrer set to 1500 rpm;

2) controlling the temperature of the calender to be 90-110° C. and the pressure to be between 10-20 MPa, and pressing the material mixed in step 1) through the calender to form a positive electrode sheet having an actual density close to 85%-90% of the theoretical density, a porosity of 30%-50% and a thickness of 150 μm;

3) The positive electrode sheet in step 2) was cut into cylindrical shapes with a diameter of 18 mm and a thickness of 150 μm, and dried in an oven at 80-100° C. for 2 hours.

The following tests were performed for Example 6:

(1) XRD analysis: Prepare the final product sample, place it on the XRD sample stage, set the XRD scanning range to 5-80°, the step length to 0.05°, and the scanning speed to 0.5 s/step, start scanning and record the diffraction data, and compare the obtained diffraction pattern with the standard card to confirm the crystal structure.

(2) SEM analysis: The sample was fixed on the SEM sample stage and subjected to conductive treatment. The magnification of the SEM was set to 5000 times and the working distance was between 5 and 10 mm to obtain the particle size distribution data of the material.

According to the tests of (1)-(2) above, the results are recorded in Table 8:

Table 8 Example 6 Test Results Statistics

It can be seen from the data in Table 8 that the XRD analysis and SEM analysis of the alkaline zinc-manganese battery conductive material of Example 6 are consistent with the standard card comparison.

Example 7

This embodiment is a preparation process of an alkaline zinc-manganese battery conductive material, comprising the following steps:

1) 100 g of manganese dioxide powder with a purity of 99.9% was weighed on an analytical balance, and sieved using a high-precision airflow classifier, with the airflow velocity set between 13 and 16 m/s and the dispersion disk speed set to 300 rpm to obtain a manganese dioxide powder with an average particle size of 4 microns, and then 85 g of the sieved manganese dioxide powder, 10 g of acetylene black with a purity of more than 99.9% and 5 g of polytetrafluoroethylene were weighed on an analytical balance, and mixed for 30 minutes using a high-speed stirrer, with the speed of the high-speed stirrer set to 2000 rpm;

2) controlling the temperature of the calender to be 90-110° C. and the pressure to be between 10-20 MPa, and pressing the material mixed in step 1) through the calender to form a positive electrode sheet having an actual density close to 85%-90% of the theoretical density, a porosity of 30%-50% and a thickness of 150 μm;

3) The positive electrode sheet in step 2) was cut into cylindrical shapes with a diameter of 18 mm and a thickness of 150 μm, and dried in an oven at 80-100° C. for 2 hours.

The following tests were performed for Example 7:

(1) XRD analysis: Prepare the final product sample, place it on the XRD sample stage, set the XRD scanning range to 5-80°, the step length to 0.05°, and the scanning speed to 0.5 s/step, start scanning and record the diffraction data, and compare the obtained diffraction pattern with the standard card to confirm the crystal structure.

(2) SEM analysis: The sample was fixed on the SEM sample stage and subjected to conductive treatment. The magnification of the SEM was set to 5000 times and the working distance was between 5 and 10 mm to obtain the particle size distribution data of the material.

According to the tests of (1)-(2) above, the results are recorded in Table 9:

Table 9 Example 7 Test Results Statistics

It can be seen from the data in Table 9 that the XRD analysis and SEM analysis of the alkaline zinc-manganese battery conductive material of Example 7 are consistent with the standard card comparison.

Example 8

The corrosion resistance test and tensile strength test were performed on three kinds of positive electrode sheets to be tested. The three kinds of positive electrode sheets to be tested are respectively called Example 3, Example 4 and Example 5. The operation steps of the corrosion resistance test are as follows:

1) Clean the surfaces of the three positive electrodes to be tested to ensure that there is no dust or other impurities attached;

2) Immerse the three types of positive electrodes to be tested in a 3.5% sodium chloride solution respectively, control the constant temperature to 40° C., and keep the solution for 72 hours;

3) Take out the samples one by one and rinse them with deionized water, observe and analyze the surface microstructure of each sample with a scanning electron microscope, record the morphological changes before and after corrosion, and qualitatively evaluate the corrosion resistance of the three tested positive electrode sheets by comparing the microscopic morphological differences before and after treatment;

4) Record the data in Table 2.

The operating steps of the tensile strength test are as follows:

1) Clamp three types of positive electrodes to be tested on a universal mechanical testing machine, set the corresponding tensile speed to 1mm/min, and the maximum load limit to 200N;

2) Start the tensile test until the sample breaks;

3) Record the data in Table 10.

Table 10 Statistics of corrosion resistance test and tensile strength test results

The experimental results are shown in Table 10. It can be seen from Table 10 that with the change of the dispersion disk rotation speed, when the dispersion disk rotation speed is 300rpm, the resistivity of the alkaline zinc-manganese battery conductive material prepared in Example 3 is 0.80Ω·mm ² /m, the tensile strength is 350MPa, and the corrosion rate is 0.20mg/cm ² /day; when the dispersion disk rotation speed is 350rpm, the resistivity of the alkaline zinc-manganese battery conductive material prepared in Example 4 is 1.00Ω·mm ² /m, the tensile strength is 390MPa, and the corrosion rate is 0.19mg/cm ² /day; when the dispersion disk rotation speed is 400rpm, the resistivity of the alkaline zinc-manganese battery conductive material prepared in Example 5 is 0.81Ω·mm ² /m, the tensile strength is 350MPa, and the corrosion rate is 0.20mg/cm ² /day. Based on the above results, it can be proved that the dispersion disk speed to maintain the strongest tensile strength and the smallest resistivity of the conductive material of the alkaline zinc-manganese battery needs to be set between 300-400rpm.

Embodiment 9

Cyclic charge and discharge tests were performed on three types of positive electrode sheets to be tested. The three types of positive electrode sheets to be tested are respectively referred to as Example 3, Example 6 and Example 7. The operation steps are as follows:

In a laboratory environment at 20°C, the three positive electrode sheets to be tested were placed in a constant temperature and humidity chamber, the current density was set to 0.5C, the charge cut-off voltage was 1.8V, and the discharge cut-off voltage was 0.1V. After 10 cycles of charge and discharge tests, the results are recorded in Table 11.

Table 11 Cyclic charge and discharge test results statistics

It can be seen from Table 11 that when the speed of the high-speed stirrer is different, the performance of the prepared alkaline zinc-manganese battery conductive material in the process of cyclic charge and discharge is different. When the speed of the high-speed stirrer is 1000rpm, the capacity retention rate of the alkaline zinc-manganese battery conductive material in Example 3 during 10 cycles of charge and discharge is 98%; when the speed of the high-speed stirrer is 1500rpm, the capacity retention rate of the alkaline zinc-manganese battery conductive material in Example 6 during 10 cycles of charge and discharge is 97%; when the speed of the high-speed stirrer is 2000rpm, the capacity retention rate of the alkaline zinc-manganese battery conductive material in Example 7 during 10 cycles of charge and discharge is 98%. This shows that when the speed of the high-speed stirrer is maintained between 1000-2000rpm, the capacity retention rate of the alkaline zinc-manganese battery conductive material during the cyclic charge and discharge is the largest.

Example 10

The range of the rolling pressure parameter setting in step (b) is based on the ground-air intelligent adaptive weighted fuzzy clustering algorithm, and the expression of the ground-air intelligent adaptive weighted fuzzy clustering algorithm is:

In formula (1), y is the calendering pressure parameter setting, h _mn is the Euclidean distance between raw materials m and raw materials n, h _cj is the Euclidean distance between raw materials c and raw materials j, m is the ordinal number of raw material m, n is the ordinal number of raw material n, c is the ordinal number of raw material c, and j is the ordinal number of raw material j, where c, j < m, n, f, B and q are constants, when the values of f and B are < m, y takes the minimum value, and when q is greater than n, y takes the maximum value;

In formula (2), α is the ordinal number of the raw material, m.lat is the latitude of the raw material m, m ² .lat is the square of the latitude of the raw material m, m.lng is the longitude of the raw material m, and m ² .lng is the square of the longitude of the raw material m;

In formula (3), β is the ordinal number of the raw material, c.lat is the latitude of the raw material m, sm ² .lat is the square of the latitude of the raw material m, m.lng is the longitude of the raw material m, and m ² .lng is the square of the longitude of the raw material m;

Δy＝Rarccos[cos ² Δh+sin ² Δh] (4)

In formula (4), Δy is the difference in pressure parameter settings, Δh is the absolute value of the difference between h _mn and h _cj , and Rarc is the inverse trigonometric function;

Δh＝|h _mn -h _cj | (5)

In formula (5), h _mn is the Euclidean distance between raw material m and raw material n, and h _cj is the Euclidean distance between raw material c and raw material j.

In the above specific embodiment, the working method of the ground-air intelligent adaptive weighted fuzzy clustering algorithm of the present invention is:

Step (1), calculating the Euclidean distances h _mn and h _cj between the raw materials according to formula (2) and formula (3), these distances represent the relative positions of the raw materials in space;

Step (2), calculating the absolute value Δh of the difference between h _mn and h _cj according to formula (5);

Step (3), calculating the difference Δy of the pressure parameter setting according to formula (4), and this difference is used to determine the adjustment range of the pressure parameter;

Step (4), calculating the calendering pressure parameter setting y according to formula (1), this value is obtained by fuzzy cluster analysis of the raw materials, and it represents the optimal pressure parameter setting;

Step (5), adjusting the pressure parameters during the calendering process according to the value of y to improve the performance of the conductive material.

In summary, the alkaline zinc-manganese battery conductive material prepared under the preparation conditions of Example 1 of the present invention has the highest capacity retention rate, the strongest corrosion resistance, the highest tensile strength, and the best conductivity, and has broad application prospects.

Claims (7)

1. An alkaline zinc-manganese battery conductive material is characterized in that: the alkaline zinc-manganese battery conductive material is prepared from manganese dioxide powder with the purity of more than 99.9%, acetylene black and an adhesive;

the manganese dioxide powder is firstly required to be screened to remove large particles and impurities, so that uniform particle size distribution of the powder is ensured, and the average particle size is 1-5 microns;

The ratio of the manganese dioxide powder to the acetylene black to the binder is 85:10:5, a step of;

the purity of the acetylene black reaches more than 99.9%;

The preparation method of the alkaline zinc-manganese battery conductive material comprises the following steps:

(1) Mixing and stirring the manganese dioxide powder with the purity of more than 99.9 percent, the acetylene black and the adhesive according to a preset proportion;

(2) Pressing and molding the mixed materials in the step (1);

(3) Slicing the positive plate pressed in the step (2) to obtain a positive plate with a certain size;

(4) Putting the positive plate in the step (3) into an oven for drying to obtain an alkaline zinc-manganese battery conductive material;

(5) Performing post-treatment and detection on the alkaline zinc-manganese battery conductive material;

The mixture in the step (1) is mixed by adopting a high-speed stirrer, and the stirring time is controlled to be 30 minutes so as to ensure that various materials are fully and uniformly mixed;

in the step (2), the temperature of the calender is controlled to be 100-200 ℃ and the pressure is controlled to be 10-30MPa, so that the porosity of the positive plate is ensured to be 30-50%, and the permeation and ion transmission of electrolyte are facilitated;

in the step (4), the drying temperature is controlled to be 80-100 ℃ for about 2 hours.

2. An application method of an alkaline zinc-manganese battery conductive material is characterized in that: the method comprises the following steps:

(a) Preparing a positive plate: mixing the manganese dioxide powder with the purity of more than 99.9%, the conductive agent and the adhesive according to a preset proportion, forming a structure with a certain porosity by a calendaring method, and then performing constant-temperature drying treatment;

(b) Preparing a negative plate: mixing zinc powder with purity of more than 99.9% and silver powder according to a certain proportion, calendaring to form flake, and then carrying out heat treatment and solidification;

(c) Sequentially superposing the positive electrode, the negative electrode and the isolating layer: introducing functional groups capable of mutually identifying on the surfaces of the positive electrode and the negative electrode, mixing the three materials in a solution, and self-assembling the three materials into a required structure according to the mutual identification relationship among the functional groups and the sequence of the positive electrode, the isolating layer and the negative electrode;

(d) Inserting the prepared electrode combination into a battery shell, and injecting prepared potassium hydroxide solution as electrolyte;

(e) And (5) sealing.

3. The application method of the alkaline zinc-manganese dioxide battery conductive material according to claim 2, which is characterized in that: the adhesive in the step (a) is polyvinylidene fluoride, the preset proportion is that the mass ratio of the manganese dioxide powder to the conductive agent is 9:1, the addition amount of the adhesive is 5-10%, the mixing method adopts an ultrasonic dispersion technology, the calendaring method adopts a double-roller calendaring machine, the porosity is maintained between 25-40%, the constant temperature drying condition is that the temperature is controlled between 80-120 ℃, and the time is set to 12-24 hours.

4. The application method of the alkaline zinc-manganese dioxide battery conductive material according to claim 2, which is characterized in that: the mass ratio of the zinc powder to the silver powder in the step (b) is 100:1-200: the mixing method of the zinc powder and the silver powder is a ball mill mixing method, the calendaring parameter is set to be 5-10MPa, the thickness of the sheet is 0.2mm plus or minus 0.02mm, and the heat treatment temperature is 60-80 ℃.

5. The application method of the alkaline zinc-manganese dioxide battery conductive material according to claim 2, which is characterized in that: the separator in the step (c) is a microporous structure formed by extruding high-density polyethylene at 150-200 ℃ through a die, stretching and heat treatment, the functional group introduced on the surface of the positive electrode is hydroxyl, the functional group introduced on the surface of the negative electrode is carboxyl, and the solution is prepared from sodium bicarbonate and succinate in a ratio of 1:1 in a molar ratio of 2 times the mass of water.

6. The application method of the alkaline zinc-manganese dioxide battery conductive material according to claim 2, which is characterized in that: the concentration of the potassium hydroxide solution in the step (d) is 10-12mol/L.

7. The application method of the alkaline zinc-manganese dioxide battery conductive material according to claim 2, which is characterized in that: the range of the pressure parameter setting of the calendaring in the step (b) is based on a ground-air adaptive weight fuzzy clustering algorithm, and the expression of the ground-air adaptive weight fuzzy clustering algorithm is as follows:

in the formula (1), y is the pressure parameter setting of calendaring, h _mn is the Euclidean distance of raw material m and raw material n, h _cj is the Euclidean distance of raw material c and raw material j, m is the ordinal number of raw material m, n is the ordinal number of raw material n, c is the ordinal number of raw material c, j is the ordinal number of raw material j, wherein c, j is less than m, n, f, B and q are constants, y takes the minimum value when the values of f and B are less than m, and y takes the maximum value when q is greater than n;

In the formula (2), α is the ordinal number of the raw material, m.lat is the latitude of the raw material m, m ².lat is the square of the latitude of the raw material m, m.lng is the longitude of the raw material m, and m ².lng is the square of the longitude of the raw material m;

in formula (3), β is the ordinal number of the raw material, c.lat is the latitude of the raw material m, sm ².lat is the square of the latitude of the raw material m, m.lng is the longitude of the raw material m, and m ².lng is the square of the longitude of the raw material m;

Δy＝Rarccos[cos²Δh+sin²Δh] (4)

In formula (4), Δy is the difference of the pressure parameter settings, Δh is the absolute value of the difference between h _mn and h _cj, and Rarc is the inverse trigonometric function;

Δh＝|h_mn-h_cj| (5)

in the formula (5), h _mn is the euclidean distance of the raw material m and the raw material n, and h _cj is the euclidean distance of the raw material c and the raw material j.