CN114420372A - Preparation method of nano silver powder for preparing silver electrode on back of solar cell - Google Patents

Preparation method of nano silver powder for preparing silver electrode on back of solar cell Download PDF

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CN114420372A
CN114420372A CN202210065472.XA CN202210065472A CN114420372A CN 114420372 A CN114420372 A CN 114420372A CN 202210065472 A CN202210065472 A CN 202210065472A CN 114420372 A CN114420372 A CN 114420372A
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silver
solution
dispersion
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silver powder
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CN114420372B (en
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竹文坤
何嵘
陈涛
雷佳
杨帆
罗勇
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Southwest University of Science and Technology
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/16—Making metallic powder or suspensions thereof using chemical processes
    • B22F9/18—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
    • B22F9/24—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/02—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of metals or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0224—Electrodes
    • H01L31/022408—Electrodes for devices characterised by at least one potential jump barrier or surface barrier
    • H01L31/022425—Electrodes for devices characterised by at least one potential jump barrier or surface barrier for solar cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy

Abstract

The invention discloses a method for preparing nano silver powder for preparing a silver electrode on the back of a solar cell panel, which comprises the following steps: to AgNO3Adding an alkaline dispersion liquid into the solution to obtain a silver-ammonia solution; adding a reducing agent into the obtained silver ammonia solution, stirring for reaction, and adding AgNO3Reducing silver ions in the solution into silver simple substance, and separating solid and liquidSeparating, wherein the separated solid is silver coarse grains; adding the obtained silver coarse particles into an alcohol dispersion solution, and stirring and reacting for 2-5 hours to obtain silver slurry dispersed in the alcohol dispersion solution; adding a dispersing agent into the silver paste liquid, stirring and dispersing to obtain silver dispersed slurry; and C, carrying out centrifugal suction filtration, washing, vacuum drying and ball milling crushing on the silver dispersion slurry obtained in the step three, and then carrying out secondary dispersion, surface treatment, washing and drying on the crushed silver powder to obtain the nano silver powder. The silver powder prepared by the method has uniform particle size distribution and good dispersibility, reduces the specific surface area and the surface roughness of the nano silver powder, reduces the uncontrollable deformation of the surface of the silver powder particles, and can be used for large-scale production.

Description

Preparation method of nano silver powder for preparing silver electrode on back of solar cell
Technical Field
The invention belongs to the technical field of preparation of solar electrode materials, and particularly relates to a preparation method of nano silver powder for preparing a silver electrode on the back of a solar cell.
Background
The ultrafine silver powder is used as the most commonly used electronic paste conductive material, is not only applied to the traditional element electrode paste and mixed integrated circuit paste, but also has huge dosage in the aspects of new application fields including solar cell paste, RFID (radio frequency identification) silver paste, PDP (plasma display panel) silver paste and the like, so that the preparation technology of the ultrafine silver powder is greatly developed. Since silver powder is an important raw material for preparing the conductive silver paste, the quality of the silver powder directly affects the performance index of the solar cell. The conventional solar cell includes a front electrode (upper electrode) and a back electrode (lower electrode), and the front electrode and the back electrode both use conductive silver paste as electrode materials; the silver powder for preparing the solar cell back electrode conductive silver paste has lower preparation difficulty than that of silver powder for a front electrode, and the preparation process is simpler. At present, the method for preparing silver powder comprises the following steps: the high-energy ball milling method, the spray thermal decomposition method, the plasma evaporation condensation method, the laser method, the electrochemical method and the like have respective problems, and the high-energy ball milling method can lead silver powder particles to generate uncertain deformation and has lower controllability; the spray thermal decomposition method has low conversion efficiency and is not suitable for large-scale production; the plasma evaporation condensation method, the laser method and the electrochemical method have long production period, complex process and high production cost; the silver powder prepared by the liquid phase reduction method has the advantages of low production cost, simple process and large production capacity, so the method becomes the most common silver powder preparation method. However, the liquid phase reduction method needs to consider how to improve the dispersibility of the silver powder particles, and the particle size distribution of the silver powder particles is more uniform, and the specific surface area of the particles is lower. Therefore, a preparation process capable of satisfying both the dispersibility of the silver powder particles and the specific surface area is required.
Disclosure of Invention
An object of the present invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.
To achieve these objects and other advantages and in accordance with the purpose of the invention, there is provided a method for preparing nano silver powder for preparing a silver electrode on a back surface of a solar cell, comprising the steps of:
step one, adding AgNO3Adding alkaline dispersion liquid into the solution to regulate AgNO3Obtaining silver ammonia solution by the pH value of the solution;
step two, adding a reducing agent into the silver ammonia solution obtained in the step one, stirring and reacting, and adding AgNO3Reducing silver ions in the solution into silver simple substance, carrying out solid-liquid separation, and separating out the solid which is silver coarse grains;
adding the silver coarse particles obtained in the step two into the alcohol dispersion solution, and stirring and reacting for 2-5 hours to obtain silver paste liquid dispersed in the alcohol dispersion solution, wherein the mass ratio of the silver coarse particles to the alcohol solution is 1: 105-117; adding a dispersing agent into the silver paste liquid, stirring, and carrying out dispersion reaction for 12-20 h to obtain silver dispersion slurry;
and step four, carrying out centrifugal suction filtration, washing, vacuum drying and ball milling crushing on the silver dispersion slurry obtained in the step three, wherein a ball milling medium is ethylene glycol, and then carrying out secondary dispersion, surface treatment, washing and drying on the crushed silver powder to obtain the nano silver powder.
Preferably, wherein AgNO in the first step3The concentration of the solution is 200-350 g/L; the alkaline dispersion liquid is formed by mixing NaOH solution with the mass fraction of 30% and 0.92g/mL ammonia water, and the NaOH solution and the ammonia waterThe volume ratio is 2: 1, and AgNO is adjusted after alkaline dispersion liquid is added3The pH value of the solution is 8-13.
Preferably, in the second step, the reducing agent is one of glucose, hydrazine hydrate, ascorbic acid, formaldehyde and sodium borohydride; when the reducing agent is glucose, the molar ratio of the glucose to the silver nitrate is more than 1: 2; when the reducing agent is hydrazine hydrate, the molar ratio of the hydrazine hydrate to the silver nitrate is more than 1: 4, and when the reducing agent is ascorbic acid, the molar ratio of the ascorbic acid to the silver nitrate is more than 1: 2; when the reducing agent is formaldehyde, the molar ratio of the formaldehyde to the silver nitrate is more than 1: 2; when the reducing agent is sodium borohydride, the molar ratio of the sodium borohydride to the silver nitrate is more than 1: 4.
Preferably, in the second step, after the reducing agent is added into the silver-ammonia solution, the stirring speed is 20r/min, the mixture is stirred for 1h and then is kept still for reaction for 1-3 h, carbon dioxide is introduced into the solution at the flow rate of 22sccm for 20-30 min, and finally the solution is heated to remove the carbon dioxide and the ammonia gas in the solution.
Preferably, the alcohol dispersion solution used in step three is prepared by the following method: weighing 200g of polyethylene glycol-400 liquid, pouring the polyethylene glycol-400 liquid into 1200-1700 mL of methanol, and performing ultrasonic dispersion for 20min at an ultrasonic frequency of 2.5-5 kHz to obtain a mixed alcohol solution A; adding citric acid and glycol into the mixed alcohol solution A, wherein the volume ratio of the citric acid to the glycol is 1: 1, and the volume of the glycol is 150-300 mL, mixing the citric acid and the glycol with the mixed alcohol solution A, heating to 70-85 ℃, and keeping the temperature for 23min to obtain an alcohol dispersion solution; the mass ratio of the alcohol dispersion solution to the silver coarse particles is 3-8: 1.
Preferably, in the third step, the dispersant accounts for 0.33% of the weight of the silver coarse particles, and the preparation method of the dispersant comprises the following steps:
s31, weighing 30-75 parts of polyvinylpyrrolidone, 10-13 parts of Tween 20, 3-4.5 parts of span 60 and 1-7 parts of polyvinyl alcohol according to parts by weight; dissolving tween 20 and span 60 in 200 parts of ethyl acetate to obtain a solution B, sequentially adding polyvinylpyrrolidone and polyvinyl alcohol into the solution B by taking the solution B as a dispersion medium, stirring at the stirring temperature of 70 ℃, and then performing ultrasonic dispersion at the ultrasonic dispersion frequency of 3kHz for 15min to obtain dispersion slurry;
and S32, filtering the dispersed slurry prepared in the S31, and carrying out vacuum drying on insoluble substances obtained by filtering for 24 hours at the drying temperature of 80-110 ℃ to obtain the dispersing agent.
Preferably, the dispersant used for the secondary dispersion of the silver powder in the fourth step is a mixed dispersant of gelatin and modified Arabic gum, and the mass ratio of the gelatin to the modified Arabic gum is 1: 2; the modification method of the modified Arabic gum comprises the following steps: slowly adding octenyl succinic anhydride into a gum arabic solution, heating the gum arabic solution to 60-65 ℃, carrying out esterification reaction on the octenyl succinic anhydride and the gum arabic for 40-50 min, and drying after the reaction is finished to obtain the modified gum arabic.
Preferably, in the fourth step, the reagent for surface treatment of the silver powder is a surfactant, and the surfactant comprises lauric acid, oleic acid, stearic acid and caprylic acid, wherein the mass ratio of the lauric acid to the oleic acid to the stearic acid to the caprylic acid is 1: 1.3-2: 0.2.
Preferably, in the fourth step, the method of secondarily dispersing, surface treating, washing and drying the pulverized silver powder includes:
step S41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, stirring and mixing to obtain silver slurry A, wherein the concentration of the ammonia water is 0.92g/mL, and the volume of the ammonia water is 2800 mL; mixing 2g of gelatin and modified Arabic gum, pouring into the silver slurry A, and ultrasonically dispersing for 25-70 min at the ultrasonic frequency of 4kHz to obtain secondary dispersed silver slurry;
step S42, adding 0.3g of surfactant into the secondary dispersion silver paste, stirring for 30min at the temperature of 30-38 ℃, wherein the stirring speed is 200r/min, and performing surface activity treatment on silver powder particles to obtain silver slurry with surface activity treatment;
step S43, performing evaporation concentration on the silver paste liquid subjected to surface activity treatment, washing the silver paste liquid subjected to evaporation concentration by using deionized water, and performing solid-liquid separation to obtain nano silver powder;
and step S44, drying the nano silver powder in a mixed gas of nitrogen and argon at the drying temperature of 50-70 ℃, and preparing the nano silver powder after water is completely evaporated.
The invention at least comprises the following beneficial effects:
(1) the silver powder prepared by the method has uniform particle size distribution and good dispersibility, reduces the specific surface area and the surface roughness of the nano silver powder, reduces the uncontrollable deformation of the surface of silver powder particles, and can be used for large-scale production;
(2) the invention takes a mixed solution of NaOH solution and ammonia water as alkaline dispersion liquid, and aims to adjust the pH of AgNO3 solution to be alkaline and make the ammonia water and AgNO react3Reacting to generate silver ammonia solution; in the process, under the condition that the reaction container is opened, the gas is introduced and flows out, so that the generated silver simple substance can be protected, the silver oxidation is prevented, and the generation of the flaky silver powder can be reduced;
(3) in the process of preparing the nano silver powder, the silver powder is dispersed twice, the coarse silver particles are firstly added into the alcohol dispersion solution to obtain silver slurry in the first dispersion, and the polyethylene glycol-400 and the ethylene glycol in the alcohol dispersion solution carry out initial dispersion on the silver slurry, so that the agglomerated flaky coarse silver particles are dispersed in the alcohol dispersion solution, and the agglomeration property of the coarse silver particles is reduced; citric acid is used as a protective agent to prevent the silver coarse particles from being oxidized; then, deeply dispersing the silver paste liquid by using a mixed dispersing agent prepared from polyvinylpyrrolidone, tween 20, span 60 and polyvinyl alcohol; because the solubility of the polyvinylpyrrolidone and the polyvinyl alcohol in the ethyl acetate is low, the tween 20 and the span 60 are dissolved by the ethyl acetate to obtain a solution B when the dispersing agent is prepared, and then the solution B is used as a dispersing medium, and after the polyvinylpyrrolidone and the polyvinyl alcohol are added, the ultrasonic dispersion is carried out to obtain a dispersed slurry, so that the mixing uniformity of the four dispersing agent monomers is improved, and the prepared dispersing agent has a good dispersing effect on the silver powder;
the second dispersion is carried out after the silver powder is crushed, the dispersing agent is a mixture of gelatin and modified Arabic gum, wherein the modified Arabic gum takes octenyl succinic anhydride as a modifying reagent, the emulsibility and the oxidation resistance of the Arabic gum are improved, the modified Arabic gum is mixed with the gelatin and disperses the silver powder, most of crushed flaky silver powder can be dispersed into silver powder particles with uniform granularity, and the uniformity of the particle size distribution of the silver powder is improved;
(4) according to the invention, after the nano silver powder is dispersed for the second time, dodecanoic acid, oleic acid, stearic acid and caprylic acid are used as surfactants to perform surface active treatment on the nano silver powder, so that the surface roughness of the nano silver powder is reduced.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.
Detailed Description
The present invention is described in further detail below to enable those skilled in the art to practice the invention with reference to the description.
It will be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.
Example 1
The preparation method of the nano silver powder for preparing the silver electrode on the back surface of the solar cell comprises the following steps:
step one, adding AgNO with the volume of 2.7L and the concentration of 200g/L3Adding alkaline dispersion liquid into the solution to regulate AgNO3The pH value of the solution is 8, so that a silver-ammonia solution is obtained, wherein the alkaline dispersion liquid is formed by mixing 30% of NaOH solution and 0.92g/mL of ammonia water in percentage by mass, and the volume ratio of the NaOH solution to the ammonia water is 2: 1;
step two, adding 200g of grapes into the silver ammonia solution obtained in the step oneStirring sugar at 20r/min for 1 hr, standing for 1.2 hr, and reacting AgNO3Reducing silver ions in the solution into silver simple substances, simultaneously introducing carbon dioxide into the solution at a flow rate of 22sccm for 25min, heating the solution, removing carbon dioxide and ammonia gas in the solution, and performing solid-liquid separation to obtain coarse silver particles as separated solids;
step three, adding the silver coarse particles obtained in the step two into the alcohol dispersion solution, and stirring and reacting for 2 hours to obtain silver paste liquid dispersed in the alcohol dispersion solution, wherein the mass ratio of the silver coarse particles to the alcohol solution is 1: 105; adding a dispersing agent into the silver paste liquid, wherein the adding amount of the dispersing agent accounts for 0.33% of the weight of the silver coarse particles, stirring, and carrying out dispersion reaction for 12 hours to obtain silver dispersion slurry; the preparation method of the alcohol dispersion solution comprises the following steps: weighing 200g of polyethylene glycol-400 liquid, pouring the polyethylene glycol-400 liquid into 1200mL of methanol, and performing ultrasonic dispersion for 20min at an ultrasonic frequency of 2.5kHz to obtain a mixed alcohol solution A; adding citric acid and glycol into the mixed alcohol solution A, wherein the volume ratio of the citric acid to the glycol is 1: 1, and the volume of the glycol is 150mL, mixing the citric acid and the glycol with the mixed alcohol solution A, heating to 70 ℃, and preserving heat for 23min to obtain an alcohol dispersion solution; the mass ratio of the alcohol dispersion solution to the silver coarse grains is 3: 1;
the preparation method of the dispersant comprises the following steps:
step S31, weighing 30g of polyvinylpyrrolidone, 10g of Tween 20, 3g of span 60 and 1.2g of polyvinyl alcohol according to parts by weight; dissolving tween 20 and span 60 in 200g of ethyl acetate to obtain a solution B, sequentially adding polyvinylpyrrolidone and polyvinyl alcohol into the solution B by taking the solution B as a dispersion medium, stirring at the stirring temperature of 70 ℃, and then performing ultrasonic dispersion at the ultrasonic dispersion frequency of 3kHz for 15min to obtain dispersion slurry;
and S32, filtering the dispersed slurry prepared in the S31, and drying the insoluble substances obtained by filtering in vacuum for 24 hours at the drying temperature of 80 ℃ to obtain the dispersing agent.
Step four, carrying out centrifugal suction filtration, washing, vacuum drying and ball milling crushing on the silver dispersion slurry obtained in the step three, wherein a ball milling medium is ethylene glycol, then carrying out secondary dispersion on the crushed silver powder by using a mixed dispersant of gelatin and modified arabic gum, and carrying out surface treatment on the secondary dispersed silver powder by using a surfactant, wherein the specific method comprises the following steps:
step S41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, stirring and mixing to obtain silver slurry A, wherein the concentration of the ammonia water is 0.92g/mL, and the volume of the ammonia water is 2800 mL; mixing 2g of gelatin and modified Arabic gum, pouring into the silver slurry A, and ultrasonically dispersing for 25min at the ultrasonic frequency of 4kHz to obtain secondary dispersed silver slurry;
step S42, adding 0.3g of surfactant into the secondary dispersion silver paste liquid, stirring for 30min at the temperature of 30 ℃, wherein the stirring speed is 200r/min, and carrying out surface activity treatment on silver powder particles to obtain silver paste liquid with surface activity treatment;
step S43, performing evaporation concentration on the silver paste liquid subjected to surface activity treatment, washing the silver paste liquid subjected to evaporation concentration by using deionized water, and performing solid-liquid separation to obtain nano silver powder;
and step S44, drying the nano silver powder in mixed gas of nitrogen and argon at 50 ℃, and preparing the nano silver powder after water is completely evaporated.
Wherein the mass ratio of the gelatin to the modified Arabic gum is 1: 2, and the modification method of the modified Arabic gum comprises the following steps: slowly adding octenyl succinic anhydride into the Arabic gum solution, heating the Arabic gum solution to 60 ℃, carrying out esterification reaction on the octenyl succinic anhydride and the Arabic gum for 40min, and drying after the reaction is finished to obtain the modified Arabic gum.
The components of the surfactant comprise lauric acid, oleic acid, stearic acid and caprylic acid, wherein the mass ratio of the lauric acid to the oleic acid to the stearic acid to the caprylic acid is 1: 1.3: 0.2.
Example 2
The preparation method of the nano silver powder for preparing the silver electrode on the back surface of the solar cell comprises the following steps:
step one, adding AgNO with the volume of 2L and the concentration of 250g/L3Adding alkaline dispersion liquid into the solution to regulate AgNO3The pH value of the solution is 9 to obtain silver ammonia solutionThe alkaline dispersion liquid is formed by mixing 30% of NaOH solution and 0.92g/mL of ammonia water in percentage by mass, and the volume ratio of the NaOH solution to the ammonia water is 2: 1;
step two, adding 504g of glucose into the silver ammonia solution obtained in the step one, stirring at the rotating speed of 20r/min for 1 hour, standing for reaction for 2 hours, and adding AgNO3Reducing silver ions in the solution into silver simple substances, simultaneously introducing carbon dioxide into the solution at a flow rate of 22sccm for 25min, heating the solution, removing carbon dioxide and ammonia gas in the solution, and performing solid-liquid separation to obtain coarse silver particles as separated solids;
step three, adding the silver coarse particles obtained in the step two into the alcohol dispersion solution, and stirring and reacting for 2 hours to obtain silver paste liquid dispersed in the alcohol dispersion solution, wherein the mass ratio of the silver coarse particles to the alcohol solution is 1: 110; adding a dispersing agent into the silver paste liquid, wherein the adding amount of the dispersing agent accounts for 0.33% of the weight of the silver coarse particles, stirring, and carrying out dispersion reaction for 12 hours to obtain silver dispersion slurry; the preparation method of the alcohol dispersion solution comprises the following steps: weighing 200g of polyethylene glycol-400 liquid, pouring the polyethylene glycol-400 liquid into 1500mL of methanol, and performing ultrasonic dispersion for 20min at the ultrasonic frequency of 4kHz to obtain a mixed alcohol solution A; adding citric acid and glycol into the mixed alcohol solution A, wherein the volume ratio of the citric acid to the glycol is 1: 1, and the volume of the glycol is 150mL, mixing the citric acid and the glycol with the mixed alcohol solution A, heating to 80 ℃, and preserving heat for 23min to obtain an alcohol dispersion solution; the mass ratio of the alcohol dispersion solution to the silver coarse grains is 3: 1;
the preparation method of the dispersant comprises the following steps:
step S31, weighing 48g of polyvinylpyrrolidone, 12g of Tween 20, 4g of span 60 and 3g of polyvinyl alcohol according to parts by weight; dissolving tween 20 and span 60 in 200g of ethyl acetate to obtain a solution B, sequentially adding polyvinylpyrrolidone and polyvinyl alcohol into the solution B by taking the solution B as a dispersion medium, stirring at the stirring temperature of 70 ℃, and then performing ultrasonic dispersion at the ultrasonic dispersion frequency of 3kHz for 15min to obtain dispersion slurry;
and S32, filtering the dispersed slurry prepared in the S31, and drying insoluble substances obtained by filtering in vacuum for 24 hours at the drying temperature of 100 ℃ to obtain the dispersing agent.
Step four, carrying out centrifugal suction filtration, washing, vacuum drying and ball milling crushing on the silver dispersion slurry obtained in the step three, wherein a ball milling medium is ethylene glycol, then carrying out secondary dispersion on the crushed silver powder by using a mixed dispersant of gelatin and modified arabic gum, and carrying out surface treatment on the secondary dispersed silver powder by using a surfactant, wherein the specific method comprises the following steps:
step S41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, stirring and mixing to obtain silver slurry A, wherein the concentration of the ammonia water is 0.92g/mL, and the volume of the ammonia water is 2800 mL; mixing 2g of gelatin and modified Arabic gum, pouring into the silver slurry A, and ultrasonically dispersing for 60min at the ultrasonic frequency of 4kHz to obtain secondary dispersed silver slurry;
step S42, adding 0.3g of surfactant into the secondary dispersion silver paste liquid, stirring for 30min at 34 ℃, wherein the stirring speed is 200r/min, and carrying out surface activity treatment on silver powder particles to obtain silver paste liquid with surface activity treatment;
step S43, performing evaporation concentration on the silver paste liquid subjected to surface activity treatment, washing the silver paste liquid subjected to evaporation concentration by using deionized water, and performing solid-liquid separation to obtain nano silver powder;
and step S44, drying the nano silver powder in mixed gas of nitrogen and argon at the drying temperature of 60 ℃, and preparing the nano silver powder after water is completely evaporated.
Wherein the mass ratio of the gelatin to the modified Arabic gum is 1: 2, and the modification method of the modified Arabic gum comprises the following steps: slowly adding octenyl succinic anhydride into the Arabic gum solution, heating the Arabic gum solution to 60 ℃, carrying out esterification reaction on the octenyl succinic anhydride and the Arabic gum for 45min, and drying after the reaction is finished to obtain the modified Arabic gum.
The components of the surfactant comprise lauric acid, oleic acid, stearic acid and caprylic acid, wherein the mass ratio of the lauric acid to the oleic acid to the stearic acid to the caprylic acid is 1: 1.7: 0.2.
Example 3
The preparation method of the nano silver powder for preparing the silver electrode on the back surface of the solar cell comprises the following steps:
step one, adding AgNO with the volume of 3L and the concentration of 300g/L3Adding alkaline dispersion liquid into the solution to regulate AgNO3The pH value of the solution is 8, so that a silver-ammonia solution is obtained, wherein the alkaline dispersion liquid is formed by mixing 30% of NaOH solution and 0.92g/mL of ammonia water in percentage by mass, and the volume ratio of the NaOH solution to the ammonia water is 2: 1;
step two, adding 900g of glucose into the silver ammonia solution obtained in the step one, stirring the mixture for 1 hour at the rotating speed of 20r/min, standing the mixture for reaction for 2 hours, and adding AgNO3Reducing silver ions in the solution into silver simple substances, simultaneously introducing carbon dioxide into the solution at a flow rate of 22sccm for 30min, heating the solution, removing carbon dioxide and ammonia gas in the solution, and performing solid-liquid separation to obtain coarse silver particles as separated solids;
step three, adding the silver coarse particles obtained in the step two into the alcohol dispersion solution, and stirring and reacting for 5 hours to obtain silver paste liquid dispersed in the alcohol dispersion solution, wherein the mass ratio of the silver coarse particles to the alcohol solution is 1: 117; adding a dispersing agent into the silver paste liquid, wherein the adding amount of the dispersing agent accounts for 0.33% of the weight of the silver coarse particles, stirring, and carrying out dispersion reaction for 20 hours to obtain silver dispersion slurry; the preparation method of the alcohol dispersion solution comprises the following steps: weighing 200g of polyethylene glycol-400 liquid, pouring the polyethylene glycol-400 liquid into 1700mL of methanol, and performing ultrasonic dispersion for 20min at an ultrasonic frequency of 5kHz to obtain a mixed alcohol solution A; adding citric acid and glycol into the mixed alcohol solution A, wherein the volume ratio of the citric acid to the glycol is 1: 1, the volume of the glycol is 300mL, mixing the citric acid and the glycol with the mixed alcohol solution A, heating to 85 ℃, and keeping the temperature for 23min to obtain an alcohol dispersion solution; the mass ratio of the alcohol dispersion solution to the silver coarse grains is 8: 1;
the preparation method of the dispersant comprises the following steps:
step S31, weighing 75g of polyvinylpyrrolidone, 13g of Tween 20, 4.5g of span 60 and 7g of polyvinyl alcohol according to parts by weight; dissolving tween 20 and span 60 in 200 parts of ethyl acetate to obtain a solution B, sequentially adding polyvinylpyrrolidone and polyvinyl alcohol into the solution B by taking the solution B as a dispersion medium, stirring at the stirring temperature of 70 ℃, and then performing ultrasonic dispersion at the ultrasonic dispersion frequency of 3kHz for 15min to obtain dispersion slurry;
and S32, filtering the dispersed slurry prepared in the S31, and drying insoluble substances obtained by filtering in vacuum for 24 hours at the drying temperature of 110 ℃ to obtain the dispersing agent.
Step four, carrying out centrifugal suction filtration, washing, vacuum drying and ball milling crushing on the silver dispersion slurry obtained in the step three, wherein a ball milling medium is ethylene glycol, then carrying out secondary dispersion on the crushed silver powder by using a mixed dispersant of gelatin and modified arabic gum, and carrying out surface treatment on the secondary dispersed silver powder by using a surfactant, wherein the specific method comprises the following steps:
step S41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, stirring and mixing to obtain silver slurry A, wherein the concentration of the ammonia water is 0.92g/mL, and the volume of the ammonia water is 2800 mL; mixing 2g of gelatin and modified Arabic gum, pouring into the silver slurry A, and ultrasonically dispersing for 70min at the ultrasonic frequency of 4kHz to obtain secondary dispersed silver slurry;
step S42, adding 0.3g of surfactant into the secondary dispersion silver paste liquid, stirring for 30min at 38 ℃, wherein the stirring speed is 200r/min, and carrying out surface activity treatment on silver powder particles to obtain silver paste liquid with surface activity treatment;
step S43, performing evaporation concentration on the silver paste liquid subjected to surface activity treatment, washing the silver paste liquid subjected to evaporation concentration by using deionized water, and performing solid-liquid separation to obtain nano silver powder;
and step S44, drying the nano silver powder in mixed gas of nitrogen and argon at 70 ℃, and preparing the nano silver powder after water is completely evaporated.
Wherein the mass ratio of the gelatin to the modified Arabic gum is 1: 2, and the modification method of the modified Arabic gum comprises the following steps: slowly adding octenyl succinic anhydride into the Arabic gum solution, heating the Arabic gum solution to 65 ℃, carrying out esterification reaction on the octenyl succinic anhydride and the Arabic gum for 50min, and drying after the reaction is finished to obtain the modified Arabic gum.
The components of the surfactant comprise lauric acid, oleic acid, stearic acid and caprylic acid, wherein the mass ratio of the lauric acid to the oleic acid to the stearic acid to the caprylic acid is 1: 2: 0.2.
Comparative example 1
The preparation method of the nano silver powder for preparing the silver electrode on the back surface of the solar cell comprises the following steps:
step one, adding AgNO with the volume of 2.7L and the concentration of 200g/L3Adding alkaline dispersion liquid into the solution to regulate AgNO3The pH value of the solution is 8, so that a silver-ammonia solution is obtained, wherein the alkaline dispersion liquid is formed by mixing 30% of NaOH solution and 0.92g/mL of ammonia water in percentage by mass, and the volume ratio of the NaOH solution to the ammonia water is 2: 1;
step two, adding 200g of glucose into the silver ammonia solution obtained in the step one, stirring at the rotating speed of 20r/min for 1 hour, standing for reaction for 1.2 hours, and adding AgNO3Reducing silver ions in the solution into silver simple substances, simultaneously introducing carbon dioxide into the solution at a flow rate of 22sccm for 25min, heating the solution, removing carbon dioxide and ammonia gas in the solution, and performing solid-liquid separation to obtain coarse silver particles as separated solids;
step three, adding the silver coarse particles obtained in the step two into the alcohol dispersion solution, and stirring and reacting for 2 hours to obtain silver paste liquid dispersed in the alcohol dispersion solution, wherein the mass ratio of the silver coarse particles to the alcohol solution is 1: 105; adding a dispersing agent into the silver paste liquid, wherein the adding amount of the dispersing agent accounts for 0.33% of the weight of the silver coarse particles, stirring, and carrying out dispersion reaction for 12 hours to obtain silver dispersion slurry; the preparation method of the alcohol dispersion solution comprises the following steps: weighing 200g of polyethylene glycol-400 liquid, pouring the polyethylene glycol-400 liquid into 1200mL of methanol, and performing ultrasonic dispersion for 20min at an ultrasonic frequency of 2.5kHz to obtain a mixed alcohol solution A; adding citric acid and glycol into the mixed alcohol solution A, wherein the volume ratio of the citric acid to the glycol is 1: 1, and the volume of the glycol is 150mL, mixing the citric acid and the glycol with the mixed alcohol solution A, heating to 70 ℃, and preserving heat for 23min to obtain an alcohol dispersion solution; the mass ratio of the alcohol dispersion solution to the silver coarse grains is 3: 1;
the preparation method of the dispersant comprises the following steps:
step S31, weighing 30g of polyvinylpyrrolidone, 10g of Tween 20, 3g of span 60 and 1.2g of polyvinyl alcohol according to parts by weight; dissolving tween 20 and span 60 in 200g of ethyl acetate to obtain a solution B, sequentially adding polyvinylpyrrolidone and polyvinyl alcohol into the solution B by taking the solution B as a dispersion medium, stirring at the stirring temperature of 70 ℃, and then performing ultrasonic dispersion at the ultrasonic dispersion frequency of 3kHz for 15min to obtain dispersion slurry;
and S32, filtering the dispersed slurry prepared in the S31, and drying the insoluble substances obtained by filtering in vacuum for 24 hours at the drying temperature of 80 ℃ to obtain the dispersing agent.
Step four, carrying out centrifugal suction filtration, washing, vacuum drying and ball milling crushing on the silver dispersion slurry obtained in the step three, wherein a ball milling medium is ethylene glycol, then carrying out secondary dispersion on the crushed silver powder by using a mixed dispersant of gelatin and Arabic gum, and carrying out surface treatment on the secondary dispersed silver powder by using a surfactant, wherein the specific method comprises the following steps:
step S41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, stirring and mixing to obtain silver slurry A, wherein the concentration of the ammonia water is 0.92g/mL, and the volume of the ammonia water is 2800 mL; mixing 2g of gelatin and Arabic gum, pouring into the silver slurry A, and ultrasonically dispersing for 25min at the ultrasonic frequency of 4kHz to obtain secondary dispersed silver slurry;
step S42, adding 0.3g of surfactant into the secondary dispersion silver paste liquid, stirring for 30min at the temperature of 30 ℃, wherein the stirring speed is 200r/min, and carrying out surface activity treatment on silver powder particles to obtain silver paste liquid with surface activity treatment;
step S43, performing evaporation concentration on the silver paste liquid subjected to surface activity treatment, washing the silver paste liquid subjected to evaporation concentration by using deionized water, and performing solid-liquid separation to obtain nano silver powder;
and step S44, drying the nano silver powder in mixed gas of nitrogen and argon at 50 ℃, and preparing the nano silver powder after water is completely evaporated.
Wherein the mass ratio of the gelatin to the Arabic gum is 1: 2;
the components of the surfactant comprise lauric acid, oleic acid, stearic acid and caprylic acid, wherein the mass ratio of the lauric acid to the oleic acid to the stearic acid to the caprylic acid is 1: 1.3: 0.2.
Comparative example 2
The preparation method of the nano silver powder for preparing the silver electrode on the back surface of the solar cell comprises the following steps:
step one, adding AgNO with the volume of 2.7L and the concentration of 200g/L3Adding alkaline dispersion liquid into the solution to regulate AgNO3The pH value of the solution is 8, so that a silver-ammonia solution is obtained, wherein the alkaline dispersion liquid is formed by mixing 30% of NaOH solution and 0.92g/mL of ammonia water in percentage by mass, and the volume ratio of the NaOH solution to the ammonia water is 2: 1;
step two, adding 200g of glucose into the silver ammonia solution obtained in the step one, stirring at the rotating speed of 20r/min for 1 hour, standing for reaction for 1.2 hours, and adding AgNO3Reducing silver ions in the solution into silver simple substances, simultaneously introducing carbon dioxide into the solution at a flow rate of 22sccm for 25min, heating the solution, removing carbon dioxide and ammonia gas in the solution, and performing solid-liquid separation to obtain coarse silver particles as separated solids;
step three, adding the silver coarse particles obtained in the step two into the alcohol dispersion solution, and stirring and reacting for 2 hours to obtain silver paste liquid dispersed in the alcohol dispersion solution, wherein the mass ratio of the silver coarse particles to the alcohol solution is 1: 105; adding a dispersing agent into the silver paste liquid, wherein the adding amount of the dispersing agent accounts for 0.33% of the weight of the silver coarse particles, stirring, and carrying out dispersion reaction for 12 hours to obtain silver dispersion slurry; the preparation method of the alcohol dispersion solution comprises the following steps: weighing 200g of polyethylene glycol-400 liquid, pouring the polyethylene glycol-400 liquid into 1200mL of methanol, and performing ultrasonic dispersion for 20min at an ultrasonic frequency of 2.5kHz to obtain a mixed alcohol solution A; adding citric acid and glycol into the mixed alcohol solution A, wherein the volume ratio of the citric acid to the glycol is 1: 1, and the volume of the glycol is 150mL, mixing the citric acid and the glycol with the mixed alcohol solution A, heating to 70 ℃, and preserving heat for 23min to obtain an alcohol dispersion solution; the mass ratio of the alcohol dispersion solution to the silver coarse grains is 3: 1;
the preparation method of the dispersant comprises the following steps:
step S31, weighing 30g of polyvinylpyrrolidone, 10g of Tween 20, 3g of span 60 and 1.2g of polyvinyl alcohol according to parts by weight; dissolving tween 20 and span 60 in 200g of ethyl acetate to obtain a solution B, sequentially adding polyvinylpyrrolidone and polyvinyl alcohol into the solution B by taking the solution B as a dispersion medium, stirring at the stirring temperature of 70 ℃, and then performing ultrasonic dispersion at the ultrasonic dispersion frequency of 3kHz for 15min to obtain dispersion slurry;
and S32, filtering the dispersed slurry prepared in the S31, and drying the insoluble substances obtained by filtering in vacuum for 24 hours at the drying temperature of 80 ℃ to obtain the dispersing agent.
Step four, carrying out centrifugal suction filtration, washing, vacuum drying and ball milling crushing on the silver dispersion slurry obtained in the step three, wherein a ball milling medium is ethylene glycol, and a surfactant is used for carrying out surface treatment on the silver powder, and the specific method comprises the following steps:
step S41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, stirring and mixing to obtain silver slurry A, wherein the concentration of the ammonia water is 0.92g/mL, and the volume of the ammonia water is 2800 mL;
step S42, adding 0.3g of surfactant into the silver paste liquid A, stirring for 30min at 30 ℃, wherein the stirring speed is 200r/min, and carrying out surface activity treatment on silver powder particles to obtain silver paste liquid with surface activity treatment;
step S43, performing evaporation concentration on the silver paste liquid subjected to surface activity treatment, washing the silver paste liquid subjected to evaporation concentration by using deionized water, and performing solid-liquid separation to obtain nano silver powder;
and step S44, drying the nano silver powder in mixed gas of nitrogen and argon at 50 ℃, and preparing the nano silver powder after water is completely evaporated.
The components of the surfactant comprise lauric acid, oleic acid, stearic acid and caprylic acid, wherein the mass ratio of the lauric acid to the oleic acid to the stearic acid to the caprylic acid is 1: 1.3: 0.2.
Comparative example 3
The preparation method of the nano silver powder for preparing the silver electrode on the back surface of the solar cell comprises the following steps:
step one, adding AgNO with the volume of 2.7L and the concentration of 200g/L3Adding alkaline dispersion liquid into the solution to regulate AgNO3The pH value of the solution is 8, so that a silver-ammonia solution is obtained, wherein the alkaline dispersion liquid is formed by mixing 30% of NaOH solution and 0.92g/mL of ammonia water in percentage by mass, and the volume ratio of the NaOH solution to the ammonia water is 2: 1;
step two, adding 200g of glucose into the silver ammonia solution obtained in the step one, stirring at the rotating speed of 20r/min for 1 hour, standing for reaction for 1.2 hours, and adding AgNO3Reducing silver ions in the solution into silver simple substances, simultaneously introducing carbon dioxide into the solution at a flow rate of 22sccm for 25min, heating the solution, removing carbon dioxide and ammonia gas in the solution, and performing solid-liquid separation to obtain coarse silver particles as separated solids;
step three, adding the silver coarse particles obtained in the step two into the alcohol dispersion solution, and stirring and reacting for 2 hours to obtain silver paste liquid dispersed in the alcohol dispersion solution, wherein the mass ratio of the silver coarse particles to the alcohol solution is 1: 105; adding a dispersing agent into the silver paste liquid, wherein the adding amount of the dispersing agent accounts for 0.33% of the weight of the silver coarse particles, stirring, and carrying out dispersion reaction for 12 hours to obtain silver dispersion slurry; the preparation method of the alcohol dispersion solution comprises the following steps: weighing 200g of polyethylene glycol-400 liquid, pouring the polyethylene glycol-400 liquid into 1200mL of methanol, and performing ultrasonic dispersion for 20min at an ultrasonic frequency of 2.5kHz to obtain a mixed alcohol solution A; adding citric acid and glycol into the mixed alcohol solution A, wherein the volume ratio of the citric acid to the glycol is 1: 1, and the volume of the glycol is 150mL, mixing the citric acid and the glycol with the mixed alcohol solution A, heating to 70 ℃, and preserving heat for 23min to obtain an alcohol dispersion solution; the mass ratio of the alcohol dispersion solution to the silver coarse grains is 3: 1;
the preparation method of the dispersant comprises the following steps:
step S31, weighing 30g of polyvinylpyrrolidone, 10g of Tween 20, 3g of span 60 and 1.2g of polyvinyl alcohol according to parts by weight; dissolving tween 20 and span 60 in 200g of ethyl acetate to obtain a solution B, sequentially adding polyvinylpyrrolidone and polyvinyl alcohol into the solution B by taking the solution B as a dispersion medium, stirring at the stirring temperature of 70 ℃, and then performing ultrasonic dispersion at the ultrasonic dispersion frequency of 3kHz for 15min to obtain dispersion slurry;
and S32, filtering the dispersed slurry prepared in the S31, and drying the insoluble substances obtained by filtering in vacuum for 24 hours at the drying temperature of 80 ℃ to obtain the dispersing agent.
Step four, carrying out centrifugal suction filtration, washing, vacuum drying and ball milling crushing on the silver dispersion slurry obtained in the step three, wherein a ball milling medium is ethylene glycol, and then carrying out secondary dispersion on the crushed silver powder by using a mixed dispersing agent of gelatin and modified arabic gum, wherein the specific method comprises the following steps:
step S41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, stirring and mixing to obtain silver slurry A, wherein the concentration of the ammonia water is 0.92g/mL, and the volume of the ammonia water is 2800 mL; mixing 2g of gelatin and modified Arabic gum, pouring into the silver slurry A, and ultrasonically dispersing for 25min at the ultrasonic frequency of 4kHz to obtain secondary dispersed silver slurry;
step S42, evaporating and concentrating the silver paste liquid subjected to the secondary dispersion treatment, washing the evaporated and concentrated silver paste liquid by using deionized water, and performing solid-liquid separation to obtain nano silver powder;
and step S44, drying the nano silver powder in mixed gas of nitrogen and argon at 50 ℃, and preparing the nano silver powder after water is completely evaporated.
Wherein the mass ratio of the gelatin to the modified Arabic gum is 1: 2, and the modification method of the modified Arabic gum comprises the following steps: slowly adding octenyl succinic anhydride into the Arabic gum solution, heating the Arabic gum solution to 60 ℃, carrying out esterification reaction on the octenyl succinic anhydride and the Arabic gum for 40min, and drying after the reaction is finished to obtain the modified Arabic gum.
Comparative example 4
The preparation method of the nano silver powder for preparing the silver electrode on the back surface of the solar cell comprises the following steps:
step one, adding AgNO with the volume of 2.7L and the concentration of 200g/L3Adding alkaline dispersion liquid into the solution to regulate AgNO3The pH value of the solution is 8, so that a silver-ammonia solution is obtained, wherein the alkaline dispersion liquid is formed by mixing 30% of NaOH solution and 0.92g/mL of ammonia water in percentage by mass, and the volume ratio of the NaOH solution to the ammonia water is 2: 1;
step two, obtaining the product from the step oneAdding 200g of glucose into the silver ammonia solution, stirring at the rotating speed of 20r/min for 1 hour, standing for reacting for 1.2 hours, and adding AgNO3Reducing silver ions in the solution into silver simple substances, simultaneously introducing carbon dioxide into the solution at a flow rate of 22sccm for 25min, heating the solution, removing carbon dioxide and ammonia gas in the solution, and performing solid-liquid separation to obtain coarse silver particles as separated solids;
step three, adding the silver coarse particles obtained in the step two into the alcohol dispersion solution, and stirring and reacting for 2 hours to obtain silver paste liquid dispersed in the alcohol dispersion solution, wherein the mass ratio of the silver coarse particles to the alcohol solution is 1: 105; adding a dispersing agent into the silver paste liquid, wherein the adding amount of the dispersing agent accounts for 0.33% of the weight of the silver coarse particles, stirring, and carrying out dispersion reaction for 12 hours to obtain silver dispersion slurry; the preparation method of the alcohol dispersion solution comprises the following steps: weighing 200g of polyethylene glycol-400 liquid, pouring the polyethylene glycol-400 liquid into 1200mL of methanol, and performing ultrasonic dispersion for 20min at an ultrasonic frequency of 2.5kHz to obtain a mixed alcohol solution A; adding citric acid and glycol into the mixed alcohol solution A, wherein the volume ratio of the citric acid to the glycol is 1: 1, and the volume of the glycol is 150mL, mixing the citric acid and the glycol with the mixed alcohol solution A, heating to 70 ℃, and preserving heat for 23min to obtain an alcohol dispersion solution; the mass ratio of the alcohol dispersion solution to the silver coarse grains is 3: 1;
the preparation method of the dispersant comprises the following steps:
step S31, weighing 30g of polyvinylpyrrolidone, 10g of Tween 20, 3g of span 60 and 1.2g of polyvinyl alcohol according to parts by weight; dissolving tween 20 and span 60 in 200g of ethyl acetate to obtain a solution B, sequentially adding polyvinylpyrrolidone and polyvinyl alcohol into the solution B by taking the solution B as a dispersion medium, stirring at the stirring temperature of 70 ℃, and then performing ultrasonic dispersion at the ultrasonic dispersion frequency of 3kHz for 15min to obtain dispersion slurry;
and S32, filtering the dispersed slurry prepared in the S31, and drying the insoluble substances obtained by filtering in vacuum for 24 hours at the drying temperature of 80 ℃ to obtain the dispersing agent.
And step four, carrying out centrifugal suction filtration, washing, vacuum drying and ball milling crushing on the silver dispersion slurry obtained in the step three, wherein the ball milling medium is ethylene glycol, so as to obtain the silver powder.
100g of the nano silver powders prepared in example 1, example 2, example 3, comparative example 1, comparative example 2, comparative example 3 and comparative example 4 were weighed, and the particle diameter, specific surface area, viscosity and tap density of each were measured to obtain the following table:
Figure BDA0003480017750000161
as can be seen from the data in the table above: the proportion of the particle size of the nano silver powder prepared in the embodiment 1 being smaller than 315nm is 90%, the proportion of the particle size of the nano silver powder prepared in the embodiment 2 being smaller than 309nm is 90%, the proportion of the particle size of the nano silver powder prepared in the embodiment 3 being smaller than 312nm is 90%, and the specific surface area of the nano silver powder prepared in the 3 embodiments is 0.61m2G and 0.61m2(ii)/g or less, viscosity of 950 or more, and tap density of 6.17g/mL or more and 6.17g/mL or more; the particle size distribution, specific surface area, viscosity and tap density of the nano silver powder prepared by the preparation method provided by the invention in the 3 embodiments are superior to those of the nano silver powder prepared by the comparative examples 1-4, and the nano silver powder prepared by the preparation method provided by the invention has more excellent dispersion performance, more uniform particle size distribution and higher tap density; in the process of preparing the nano silver powder, the silver paste liquid is not dispersed for the second time by using the gelatin and the modified Arabic gum in the comparative example 1; comparative example 2 in the process of preparing the nano silver powder, the silver paste liquid is dispersed for the second time without using a dispersing agent; comparative example 3 in the process of preparing the nano silver powder, the silver paste liquid is not subjected to surface treatment by using a surfactant; comparative example 4 in the process of preparing the nano silver powder, the nano silver powder primarily dispersed and pulverized was not secondarily dispersed and surface-treated.
The number of apparatuses and the scale of the process described herein are intended to simplify the description of the present invention. Applications, modifications and variations of the present invention will be apparent to those skilled in the art.
While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable in various fields of endeavor to which the invention pertains, and further modifications may readily be made by those skilled in the art, it being understood that the invention is not limited to the details shown and described herein without departing from the general concept defined by the appended claims and their equivalents.

Claims (9)

1. A preparation method of nano silver powder for preparing a silver electrode on the back surface of a solar cell is characterized by comprising the following steps:
step one, adding AgNO3Adding alkaline dispersion liquid into the solution to regulate AgNO3Obtaining silver ammonia solution by the pH value of the solution;
step two, adding a reducing agent into the silver ammonia solution obtained in the step one, stirring and reacting, and adding AgNO3Reducing silver ions in the solution into silver simple substance, carrying out solid-liquid separation, and separating out the solid which is silver coarse grains;
adding the silver coarse particles obtained in the step two into the alcohol dispersion solution, and stirring and reacting for 2-5 hours to obtain silver paste liquid dispersed in the alcohol dispersion solution, wherein the mass ratio of the silver coarse particles to the alcohol solution is 1: 105-117; adding a dispersing agent into the silver paste liquid, stirring, and carrying out dispersion reaction for 12-20 h to obtain silver dispersion slurry;
and step four, carrying out centrifugal suction filtration, washing, vacuum drying and ball milling crushing on the silver dispersion slurry obtained in the step three, wherein a ball milling medium is ethylene glycol, and then carrying out secondary dispersion, surface treatment, washing and drying on the crushed silver powder to obtain the nano silver powder.
2. The method for preparing nano silver powder for preparing a solar cell back silver electrode according to claim 1, wherein the AgNO in the first step3The concentration of the solution is 200-350 g/L; the alkaline dispersion liquid is formed by mixing NaOH solution with the mass fraction of 30% and 0.92g/mL ammonia water, the volume ratio of the NaOH solution to the ammonia water is 2: 1, and AgNO is adjusted after the alkaline dispersion liquid is added3The pH value of the solution is 8-13.
3. The method for preparing silver nanopowder for solar cell back surface electrodes according to claim 1, wherein in the second step, the reducing agent is one of glucose, hydrazine hydrate, ascorbic acid, formaldehyde and sodium borohydride; when the reducing agent is glucose, the molar ratio of the glucose to the silver nitrate is more than 1: 2; when the reducing agent is hydrazine hydrate, the molar ratio of the hydrazine hydrate to the silver nitrate is more than 1: 4, and when the reducing agent is ascorbic acid, the molar ratio of the ascorbic acid to the silver nitrate is more than 1: 2; when the reducing agent is formaldehyde, the molar ratio of the formaldehyde to the silver nitrate is more than 1: 2; when the reducing agent is sodium borohydride, the molar ratio of the sodium borohydride to the silver nitrate is more than 1: 4.
4. The method for preparing silver nanoparticles for preparing the back silver electrode of the solar cell according to claim 2, wherein in the second step, after the reducing agent is added into the silver-ammonia solution, the stirring speed is 20r/min, the mixture is stirred for 1h and then is subjected to a static reaction for 1-3 h, carbon dioxide is introduced into the solution at a flow rate of 22sccm for 20-30 min, and finally the solution is heated to remove the carbon dioxide and the ammonia gas in the solution.
5. The method for preparing silver nano-powder for preparing a silver electrode on the back surface of a solar cell according to claim 1, wherein the alcohol dispersion solution used in the third step is prepared by: weighing 200g of polyethylene glycol-400 liquid, pouring the polyethylene glycol-400 liquid into 1200-1700 mL of methanol, and performing ultrasonic dispersion for 20min at an ultrasonic frequency of 2.5-5 kHz to obtain a mixed alcohol solution A; adding citric acid and glycol into the mixed alcohol solution A, wherein the volume ratio of the citric acid to the glycol is 1: 1, and the volume of the glycol is 150-300 mL, mixing the citric acid and the glycol with the mixed alcohol solution A, heating to 70-85 ℃, and keeping the temperature for 23min to obtain an alcohol dispersion solution; the mass ratio of the alcohol dispersion solution to the silver coarse particles is 3-8: 1.
6. The method for preparing nano silver powder for preparing a silver electrode on the back surface of a solar cell according to claim 1, wherein the dispersant accounts for 0.33% of the weight of the coarse silver particles in the third step, and the method for preparing the dispersant comprises the following steps:
s31, weighing 30-75 parts of polyvinylpyrrolidone, 10-13 parts of Tween 20, 3-4.5 parts of span 60 and 1-7 parts of polyvinyl alcohol according to parts by weight; dissolving tween 20 and span 60 in 200 parts of ethyl acetate to obtain a solution B, sequentially adding polyvinylpyrrolidone and polyvinyl alcohol into the solution B by taking the solution B as a dispersion medium, stirring at the stirring temperature of 70 ℃, and then performing ultrasonic dispersion at the ultrasonic dispersion frequency of 3kHz for 15min to obtain dispersion slurry;
and S32, filtering the dispersed slurry prepared in the S31, and carrying out vacuum drying on insoluble substances obtained by filtering for 24 hours at the drying temperature of 80-110 ℃ to obtain the dispersing agent.
7. The method for preparing silver nanopowder for solar cell back surface silver electrode according to claim 1, wherein the dispersant used in the secondary dispersion of silver powder in the fourth step is a mixed dispersant of gelatin and modified gum arabic in a mass ratio of 1: 2; the modification method of the modified Arabic gum comprises the following steps: slowly adding octenyl succinic anhydride into a gum arabic solution, heating the gum arabic solution to 60-65 ℃, carrying out esterification reaction on the octenyl succinic anhydride and the gum arabic for 40-50 min, and drying after the reaction is finished to obtain the modified gum arabic.
8. The method for preparing silver nanoparticles for preparing a solar cell back silver electrode according to claim 7, wherein in the fourth step, the reagent for surface treatment of silver powder is a surfactant, and the surfactant comprises dodecanoic acid, oleic acid, stearic acid and caprylic acid, wherein the mass ratio of dodecanoic acid to oleic acid to stearic acid to caprylic acid is 1: 1.3-2: 0.2.
9. The method for preparing silver nanopowder for solar cell back surface silver electrode according to claim 8, wherein in the fourth step, the method for performing secondary dispersion, surface treatment, washing and drying of the crushed silver powder comprises:
step S41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, stirring and mixing to obtain silver slurry A, wherein the concentration of the ammonia water is 0.92g/mL, and the volume of the ammonia water is 2800 mL; mixing 2g of gelatin and modified Arabic gum, pouring into the silver slurry A, and ultrasonically dispersing for 25-70 min at the ultrasonic frequency of 4kHz to obtain secondary dispersed silver slurry;
step S42, adding 0.3g of surfactant into the secondary dispersion silver paste, stirring for 30min at the temperature of 30-38 ℃, wherein the stirring speed is 200r/min, and performing surface activity treatment on silver powder particles to obtain silver slurry with surface activity treatment;
step S43, performing evaporation concentration on the silver paste liquid subjected to surface activity treatment, washing the silver paste liquid subjected to evaporation concentration by using deionized water, and performing solid-liquid separation to obtain nano silver powder;
and step S44, drying the nano silver powder in a mixed gas of nitrogen and argon at the drying temperature of 50-70 ℃, and preparing the nano silver powder after water is completely evaporated.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114799200A (en) * 2022-05-19 2022-07-29 中科铜都粉体新材料股份有限公司 Preparation method of high-dispersibility silver powder
CN116002734A (en) * 2023-01-17 2023-04-25 西南科技大学 Production process of high-purity high-dispersibility nanoscale alumina

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101279376A (en) * 2008-05-15 2008-10-08 金川集团有限公司 Preparation of high dispersed superfine spherical silver powder for conductive silver slurry
CN102921944A (en) * 2012-11-05 2013-02-13 昆明理工大学 Silver powder for printing size for solar cell electrodes and preparation process thereof
CN105397103A (en) * 2015-11-01 2016-03-16 华南理工大学 Nano-silver/graphene composite material and preparation method thereof
CN106862588A (en) * 2017-01-23 2017-06-20 湖南省国银新材料有限公司 A kind of preparation method of laser engraving touch-screen silver paste super fine silver powder
KR20180083226A (en) * 2017-01-12 2018-07-20 주식회사 테라메탈 Method of preparing silver powder by continuous solution reduction and the apparatus thereof
CN108941609A (en) * 2018-09-10 2018-12-07 河南金渠银通金属材料有限公司 Solar cell conductive silver paste high performance spherical super fine silver powder and preparation method thereof

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101279376A (en) * 2008-05-15 2008-10-08 金川集团有限公司 Preparation of high dispersed superfine spherical silver powder for conductive silver slurry
CN102921944A (en) * 2012-11-05 2013-02-13 昆明理工大学 Silver powder for printing size for solar cell electrodes and preparation process thereof
CN105397103A (en) * 2015-11-01 2016-03-16 华南理工大学 Nano-silver/graphene composite material and preparation method thereof
KR20180083226A (en) * 2017-01-12 2018-07-20 주식회사 테라메탈 Method of preparing silver powder by continuous solution reduction and the apparatus thereof
CN106862588A (en) * 2017-01-23 2017-06-20 湖南省国银新材料有限公司 A kind of preparation method of laser engraving touch-screen silver paste super fine silver powder
CN108941609A (en) * 2018-09-10 2018-12-07 河南金渠银通金属材料有限公司 Solar cell conductive silver paste high performance spherical super fine silver powder and preparation method thereof

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114799200A (en) * 2022-05-19 2022-07-29 中科铜都粉体新材料股份有限公司 Preparation method of high-dispersibility silver powder
CN114799200B (en) * 2022-05-19 2023-12-12 中科铜都粉体新材料股份有限公司 Preparation method of high-dispersity silver powder
CN116002734A (en) * 2023-01-17 2023-04-25 西南科技大学 Production process of high-purity high-dispersibility nanoscale alumina

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