CN114420372B - 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

Info

Publication number
CN114420372B
CN114420372B CN202210065472.XA CN202210065472A CN114420372B CN 114420372 B CN114420372 B CN 114420372B CN 202210065472 A CN202210065472 A CN 202210065472A CN 114420372 B CN114420372 B CN 114420372B
Authority
CN
China
Prior art keywords
silver
solution
dispersion
silver powder
slurry
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202210065472.XA
Other languages
Chinese (zh)
Other versions
CN114420372A (en
Inventor
竹文坤
何嵘
陈涛
雷佳
杨帆
罗勇
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Southwest University of Science and Technology
Original Assignee
Southwest University of Science and Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Southwest University of Science and Technology filed Critical Southwest University of Science and Technology
Priority to CN202210065472.XA priority Critical patent/CN114420372B/en
Publication of CN114420372A publication Critical patent/CN114420372A/en
Application granted granted Critical
Publication of CN114420372B publication Critical patent/CN114420372B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Nanotechnology (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Computer Hardware Design (AREA)
  • Electromagnetism (AREA)
  • Sustainable Energy (AREA)
  • Sustainable Development (AREA)
  • Composite Materials (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Manufacture Of Metal Powder And Suspensions Thereof (AREA)

Abstract

The invention discloses a preparation method of nanometer silver powder for preparing a silver electrode on the back of a solar cell panel, which comprises the following steps: to AgNO 3 Adding alkaline dispersion liquid into the solution to obtain silver-ammonia solution; adding a reducing agent into the obtained silver ammonia solution, stirring for reaction, and carrying out AgNO 3 Reducing silver ions in the solution into silver simple substances, and carrying out solid-liquid separation, wherein the separated solids are silver coarse grains; adding the obtained silver coarse particles into an alcohol dispersion solution, and stirring and reacting for 2-5 h to obtain silver slurry dispersed by the alcohol dispersion solution; adding a dispersing agent into the silver slurry, and stirring and dispersing to obtain silver dispersion slurry; and (3) carrying out centrifugal suction filtration, washing, vacuum drying and ball milling on the silver dispersion slurry obtained in the step (III), 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 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 solar electrode material preparation, 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 superfine silver powder is used as the most commonly used electronic paste conductive material, is not only applied to the traditional element electrode paste and the mixed integrated circuit paste, but also has huge dosage in the new application fields including solar battery paste, RFID silver paste, PDP silver paste and the like, so the preparation technology of the superfine 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 existing solar cell comprises a front electrode (upper electrode) and a back electrode (lower electrode), wherein the front electrode and the back electrode both use conductive silver paste as electrode materials; the silver powder for preparing the conductive silver paste for the back electrode of the solar cell is lower in preparation difficulty than silver powder for the front electrode, and the preparation process is simpler. Currently, the method for preparing silver powder comprises the following steps: high-energy ball milling, spray pyrolysis, plasma evaporation condensation, laser, electrochemical methods and the like, but the high-energy ball milling method can lead silver powder particles to generate uncertain deformation and has low controllability; the spray pyrolysis 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 liquid phase reduction method for preparing the silver powder has the advantages of low production cost, simple process and large production capacity, so that the method becomes the most commonly used silver powder preparation method. However, the liquid phase reduction method needs to consider how to improve the dispersion performance of silver powder particles, and make the particle size distribution of the silver powder particles more uniform, and the specific surface area of the particles lower, and because the solar conductive silver paste has certain requirements on the surfaces of the silver powder particles, the surfaces of the silver powder particles are required to be smooth, the specific surface area is required to be lower, and the particle size and the inter-particle size of the silver powder particles can influence the crosstalk resistance of the prepared silver paste. Therefore, there is a need for a preparation process that can achieve both the dispersion properties and the specific surface area of silver powder particles.
Disclosure of Invention
It is an object of the present invention to address at least the above problems and/or disadvantages and to provide at least the advantages described below.
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 back side silver electrode of a solar cell, comprising the steps of:
step one, to AgNO 3 Adding alkaline dispersion liquid into the solution to regulate AgNO 3 The pH value of the solution is used for obtaining silver-ammonia solution;
step two, adding a reducing agent into the silver ammonia solution obtained in the step one, stirring for reaction, and carrying out AgNO reaction 3 Reducing silver ions in the solution into silver simple substances, and carrying out solid-liquid separation, wherein the separated solids are silver coarse grains;
adding the silver coarse particles obtained in the step two into an alcohol dispersion solution, and stirring and reacting for 2-5 hours to obtain silver slurry dispersed by 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 slurry, stirring and carrying out dispersion reaction for 12-20 hours to obtain silver dispersion slurry;
and step four, carrying out centrifugal suction filtration, washing, vacuum drying and ball milling and 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 the AgNO in the step one 3 The 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 regulated after the alkaline dispersion liquid is added 3 The pH 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 formaldehyde to silver nitrate is greater than 1:2; when the reducing agent is sodium borohydride, the molar ratio of sodium borohydride to silver nitrate is greater than 1:4.
Preferably, in the second step, after adding the reducing agent into the silver-ammonia solution, stirring at a speed of 20r/min, standing for 1-3 h after stirring for 1h, introducing carbon dioxide into the solution at a flow rate of 22sccm for 20-30 min, and finally heating the solution to remove carbon dioxide and ammonia in the solution.
Preferably, the method for preparing the alcohol dispersion solution used in the third step comprises the following steps: 200g of polyethylene glycol-400 liquid is weighed, the polyethylene glycol-400 liquid is poured into 1200-1700 mL of methanol, ultrasonic dispersion is carried out for 20min, the ultrasonic frequency is 2.5-5 kHz, and a mixed alcohol solution A is obtained; 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 150-300 mL, mixing the citric acid, the glycol and the mixed alcohol solution A, heating to 70-85 ℃, and preserving heat 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, the dispersing agent in the third step accounts for 0.33% of the weight of the silver coarse particles, and the preparation method of the dispersing agent comprises the following steps:
step 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 70 ℃, then performing ultrasonic dispersion with the frequency of 3kHz and the dispersion time of 15min to obtain dispersion slurry;
And S32, filtering the dispersion slurry obtained in the step S31, and vacuum drying insoluble matters obtained by filtering for 24 hours at the drying temperature of 80-110 ℃ to obtain the dispersing agent.
Preferably, the dispersing agent used in the second dispersion of silver powder in the fourth step is a mixed dispersing agent of gelatin and modified acacia, and the mass ratio of gelatin to modified acacia is 1:2; the modification method of the modified Arabic gum comprises the following steps: slowly adding octenyl succinic anhydride into a acacia solution, heating the acacia solution to 60-65 ℃, carrying out esterification reaction on the octenyl succinic anhydride and the acacia for 40-50 min, and drying after the reaction is finished to obtain the modified acacia.
Preferably, in the fourth step, the reagent for surface treatment of silver powder is a surfactant, and the components of the surfactant include dodecanoic acid, oleic acid, stearic acid and octanoic acid, wherein the mass ratio of the dodecanoic acid, the oleic acid, the stearic acid and the octanoic acid is 1:1:1.3-2:0.2.
Preferably, in the fourth step, the method for performing secondary dispersion, surface treatment, washing and drying on the crushed silver powder includes:
S41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, wherein the concentration of the ammonia water is 0.92g/mL, the volume of the ammonia water is 2800mL, and stirring and mixing to obtain silver slurry A; mixing 2g of gelatin and modified Arabic gum, pouring into the silver slurry A, and performing ultrasonic dispersion for 25-70 min at an ultrasonic frequency of 4kHz to obtain secondary dispersion silver slurry;
s42, adding 0.3g of surfactant into the secondary dispersion silver slurry, stirring for 30min at 30-38 ℃ at the stirring speed of 200r/min, and carrying out surface activity treatment on silver powder particles to obtain surface activity treated silver slurry;
step S43, evaporating and concentrating the silver slurry subjected to surface activity treatment, washing the evaporated and concentrated silver slurry by using deionized water, and carrying out solid-liquid separation to obtain nano silver powder;
and S44, drying the nano silver powder in a mixed gas of nitrogen and argon at a drying temperature of 50-70 ℃ until the water is evaporated completely, so as to prepare the nano silver powder.
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 uses the mixed solution of NaOH solution and ammonia water as alkaline dispersion liquid, and the purpose is to adjust the pH value of AgNO3 solution to be alkaline, so that the ammonia water and AgNO 3 Reacting to generate silver ammonia solution; and after the reducing agent is added into the silver ammonia solution, continuously introducing carbon dioxide, carbon dioxide and sodium hydroxideAnd ammonia water is reacted to generate sodium carbonate and ammonium bicarbonate, and then part of carbon dioxide and ammonia gas are removed by reheating, in the process, under the condition that a reaction container is open, the generated silver simple substance can be protected by the gas inlet and outlet, the silver oxidation can be prevented, and the generation of flake silver powder can be reduced;
(3) In the process of preparing the nano silver powder, silver powder is dispersed twice, silver coarse particles are added into an alcohol dispersion solution to obtain silver slurry in the first dispersion, and polyethylene glycol-400 and ethylene glycol in the alcohol dispersion solution initially disperse the silver slurry, so that agglomerated flaky silver coarse particles are dispersed in the alcohol dispersion solution, and the agglomeration of silver coarse particles is reduced; citric acid is used as a protective agent to prevent the oxidation of silver coarse particles; then, deeply dispersing silver slurry by using a mixed dispersing agent prepared from polyvinylpyrrolidone, tween 20, span 60 and polyvinyl alcohol; because the solubility of polyvinylpyrrolidone and polyvinyl alcohol in ethyl acetate is low, tween 20 and span 60 are dissolved by ethyl acetate to obtain a solution B when the dispersing agent is prepared, and then the solution B is taken as a dispersing medium, and after the polyvinylpyrrolidone and the polyvinyl alcohol are added, the dispersing slurry is obtained by ultrasonic dispersion, so that the mixing uniformity of four dispersing agent monomers is improved, and the prepared dispersing agent has a good dispersing effect on silver powder;
The second dispersing is carried out after the silver powder is crushed, and 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, so that the emulsifying property and the antioxidation capability of Arabic gum are improved, the modified Arabic gum is mixed with gelatin, and the silver powder is dispersed, so that most of crushed flaky silver powder can be dispersed into silver powder particles with uniform granularity, and the particle size distribution uniformity of the silver powder is improved;
(4) According to the invention, after the nano silver powder is dispersed for the second time, the surface active agent is prepared from the dodecanoic acid, the oleic acid, the stearic acid and the octanoic acid, 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 by reference to the specification.
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 side of the solar cell comprises the following steps:
step one, agNO with the concentration of 200g/L is added to the volume of 2.7L 3 Adding alkaline dispersion liquid into the solution to regulate AgNO 3 The pH value of the solution is 8, and a silver ammonia solution is obtained, wherein the alkaline dispersion liquid is formed by mixing NaOH solution with the mass fraction of 30% and 0.92g/mL ammonia water, 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 for 1h at a rotating speed of 20r/min, standing for reaction for 1.2h, and obtaining AgNO 3 Reducing silver ions in the solution into silver simple substance, 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 carrying out solid-liquid separation, wherein the separated solids are silver coarse particles;
adding the silver coarse particles obtained in the step two into an alcohol dispersion solution, and stirring and reacting for 2 hours to obtain silver slurry dispersed by 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 slurry, wherein the adding amount of the dispersing agent accounts for 0.33% of the weight of the silver coarse particles, and stirring and dispersing the silver coarse particles for 12 hours to obtain silver dispersion slurry; the preparation method of the alcohol dispersion solution comprises the following steps: 200g of polyethylene glycol-400 liquid is weighed, the polyethylene glycol-400 liquid is poured into 1200mL of methanol, ultrasonic dispersion is carried out for 20min, and the ultrasonic frequency is 2.5kHz, so as 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 150mL, mixing the citric acid, the glycol and 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 particles is 3:1;
The preparation method of the dispersing agent 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 70 ℃, then performing ultrasonic dispersion with the frequency of 3kHz and the dispersion time of 15min to obtain dispersion slurry;
and S32, filtering the dispersion slurry obtained in the step S31, and vacuum drying insoluble matters obtained by filtering 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 and 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 crushed silver powder by using a mixed dispersing agent of gelatin and modified Arabic gum, and carrying out surface treatment on the secondarily dispersed silver powder by using a surfactant, wherein the specific method comprises the following steps of:
s41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, wherein the concentration of the ammonia water is 0.92g/mL, the volume of the ammonia water is 2800mL, and stirring and mixing to obtain silver slurry A; mixing 2g of gelatin and modified Arabic gum, pouring into the silver slurry A, and performing ultrasonic dispersion for 25min at an ultrasonic frequency of 4kHz to obtain secondary dispersion silver slurry;
S42, adding 0.3g of surfactant into the secondary dispersion silver slurry, stirring for 30min at 30 ℃ at the stirring speed of 200r/min, and performing surface active treatment on silver powder particles to obtain surface active treated silver slurry;
step S43, evaporating and concentrating the silver slurry subjected to surface activity treatment, washing the evaporated and concentrated silver slurry by using deionized water, and carrying out solid-liquid separation to obtain nano silver powder;
and S44, drying the nano silver powder in a mixed gas of nitrogen and argon at a drying temperature of 50 ℃ until the water is evaporated completely, and thus obtaining the nano silver powder.
Wherein the mass ratio of the gelatin to the modified Arabic gum is 1:2, and the modification method of the modified Arabic gum is as follows: slowly adding octenyl succinic anhydride into a acacia solution, heating the acacia solution to 60 ℃, carrying out esterification reaction on the octenyl succinic anhydride and acacia for 40min, and drying after the reaction is finished to obtain modified acacia.
The components of the surfactant comprise dodecanoic acid, oleic acid, stearic acid and octanoic acid, wherein the mass ratio of the dodecanoic acid, the oleic acid, the stearic acid and the octanoic acid is 1:1:1.3:0.2.
Example 2
The preparation method of the nano silver powder for preparing the silver electrode on the back side of the solar cell comprises the following steps:
step one, agNO with the concentration of 250g/L is added to the volume of 2L 3 Adding alkaline dispersion liquid into the solution to regulate AgNO 3 The pH value of the solution is 9 to obtain silver-ammonia solution, wherein the alkaline dispersion liquid is formed by mixing NaOH solution with the mass fraction of 30% and 0.92g/mL ammonia water, and the volume ratio of the NaOH solution to the ammonia water is 2:1;
adding 504g of glucose into the silver ammonia solution obtained in the step one, stirring for 1h at a rotating speed of 20r/min, standing for 2h, and reacting AgNO 3 Reducing silver ions in the solution into silver simple substance, 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 carrying out solid-liquid separation, wherein the separated solids are silver coarse particles;
adding the silver coarse particles obtained in the step two into an alcohol dispersion solution, and stirring and reacting for 2 hours to obtain silver slurry dispersed by 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 slurry, wherein the adding amount of the dispersing agent accounts for 0.33% of the weight of the silver coarse particles, and stirring and dispersing the silver coarse particles for 12 hours to obtain silver dispersion slurry; the preparation method of the alcohol dispersion solution comprises the following steps: 200g of polyethylene glycol-400 liquid is weighed, the polyethylene glycol-400 liquid is poured into 1500mL of methanol, the ultrasonic dispersion is carried out for 20min, the ultrasonic frequency is 4kHz, and a mixed alcohol solution A is obtained; 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 150mL, mixing the citric acid, the glycol and 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 particles is 3:1;
The preparation method of the dispersing agent 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 70 ℃, then performing ultrasonic dispersion with the frequency of 3kHz and the dispersion time of 15min to obtain dispersion slurry;
and S32, filtering the dispersion slurry obtained in the step S31, and vacuum drying insoluble matters obtained by filtering for 24 hours at a drying temperature of 100 ℃ to obtain the dispersing agent.
And step four, carrying out centrifugal suction filtration, washing, vacuum drying and ball milling and 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 crushed silver powder by using a mixed dispersing agent of gelatin and modified Arabic gum, and carrying out surface treatment on the secondarily dispersed silver powder by using a surfactant, wherein the specific method comprises the following steps of:
s41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, wherein the concentration of the ammonia water is 0.92g/mL, the volume of the ammonia water is 2800mL, and stirring and mixing to obtain silver slurry A; mixing 2g of gelatin and modified Arabic gum, pouring into the silver slurry A, and performing ultrasonic dispersion for 60min at an ultrasonic frequency of 4kHz to obtain secondary dispersion silver slurry;
S42, adding 0.3g of surfactant into the secondary dispersion silver slurry, stirring for 30min at 34 ℃ at the stirring speed of 200r/min, and performing surface active treatment on silver powder particles to obtain surface active treated silver slurry;
step S43, evaporating and concentrating the silver slurry subjected to surface activity treatment, washing the evaporated and concentrated silver slurry by using deionized water, and carrying out solid-liquid separation to obtain nano silver powder;
and S44, drying the nano silver powder in a mixed gas of nitrogen and argon at a drying temperature of 60 ℃ until the water is evaporated completely, and thus obtaining the nano silver powder.
Wherein the mass ratio of the gelatin to the modified Arabic gum is 1:2, and the modification method of the modified Arabic gum is as follows: slowly adding octenyl succinic anhydride into a acacia solution, heating the acacia solution to 60 ℃, carrying out esterification reaction on the octenyl succinic anhydride and acacia for 45min, and drying after the reaction is finished to obtain modified acacia.
The components of the surfactant comprise dodecanoic acid, oleic acid, stearic acid and octanoic acid, wherein the mass ratio of the dodecanoic acid, the oleic acid, the stearic acid and the octanoic acid is 1:1:1.7:0.2.
Example 3
The preparation method of the nano silver powder for preparing the silver electrode on the back side of the solar cell comprises the following steps:
step one, agNO with concentration of 300g/L is added to 3L of volume 3 Adding alkaline dispersion liquid into the solution to regulate AgNO 3 The pH value of the solution is 8, and a silver ammonia solution is obtained, wherein the alkaline dispersion liquid is formed by mixing NaOH solution with the mass fraction of 30% and 0.92g/mL ammonia water, 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 for 1h at a rotating speed of 20r/min, standing for 2h, and reacting AgNO 3 Reducing silver ions in the solution into silver simple substance, 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 carrying out solid-liquid separation, wherein the separated solids are silver coarse particles;
adding the silver coarse particles obtained in the step two into an alcohol dispersion solution, and stirring and reacting for 5 hours to obtain silver slurry dispersed by 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 slurry, wherein the adding amount of the dispersing agent accounts for 0.33% of the weight of the silver coarse particles, and stirring and dispersing the silver coarse particles for 20 hours to obtain silver dispersion slurry; the preparation method of the alcohol dispersion solution comprises the following steps: 200g of polyethylene glycol-400 liquid is weighed, the polyethylene glycol-400 liquid is poured into 1700mL of methanol, ultrasonic dispersion is carried out for 20min, and the ultrasonic frequency is 5kHz, so as 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, the glycol and the mixed alcohol solution A, heating to 85 ℃, and preserving heat for 23min to obtain an alcohol dispersion solution; the mass ratio of the alcohol dispersion solution to the silver coarse particles is 8:1;
The preparation method of the dispersing agent 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 70 ℃, then performing ultrasonic dispersion with the frequency of 3kHz and the dispersion time of 15min to obtain dispersion slurry;
and S32, filtering the dispersion slurry obtained in the step S31, and vacuum drying insoluble matters obtained by filtering for 24 hours at the drying temperature of 110 ℃ to obtain the dispersing agent.
And step four, carrying out centrifugal suction filtration, washing, vacuum drying and ball milling and 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 crushed silver powder by using a mixed dispersing agent of gelatin and modified Arabic gum, and carrying out surface treatment on the secondarily dispersed silver powder by using a surfactant, wherein the specific method comprises the following steps of:
s41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, wherein the concentration of the ammonia water is 0.92g/mL, the volume of the ammonia water is 2800mL, and stirring and mixing to obtain silver slurry A; mixing 2g of gelatin and modified Arabic gum, pouring into the silver slurry A, and performing ultrasonic dispersion for 70min at an ultrasonic frequency of 4kHz to obtain secondary dispersion silver slurry;
S42, adding 0.3g of surfactant into the secondary dispersion silver slurry, stirring for 30min at 38 ℃ at the stirring speed of 200r/min, and performing surface active treatment on silver powder particles to obtain surface active treated silver slurry;
step S43, evaporating and concentrating the silver slurry subjected to surface activity treatment, washing the evaporated and concentrated silver slurry by using deionized water, and carrying out solid-liquid separation to obtain nano silver powder;
and S44, drying the nano silver powder in a mixed gas of nitrogen and argon at a drying temperature of 70 ℃ until the water is evaporated completely, so as to prepare the nano silver powder.
Wherein the mass ratio of the gelatin to the modified Arabic gum is 1:2, and the modification method of the modified Arabic gum is as follows: slowly adding octenyl succinic anhydride into the acacia solution, heating the acacia solution to 65 ℃, carrying out esterification reaction on the octenyl succinic anhydride and the acacia for 50min, and drying after the reaction is finished to obtain the modified acacia.
The components of the surfactant comprise dodecanoic acid, oleic acid, stearic acid and octanoic acid, wherein the mass ratio of the dodecanoic acid, the oleic acid, the stearic acid and the octanoic acid is 1:1:2:0.2.
Comparative example 1
The preparation method of the nano silver powder for preparing the silver electrode on the back side of the solar cell comprises the following steps:
step one, agNO with the concentration of 200g/L is added to the volume of 2.7L 3 Adding alkaline dispersion liquid into the solution to regulate AgNO 3 The pH value of the solution is 8, and a silver ammonia solution is obtained, wherein the alkaline dispersion liquid is formed by mixing NaOH solution with the mass fraction of 30% and 0.92g/mL ammonia water, 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 for 1h at a rotating speed of 20r/min, standing for reaction for 1.2h, and obtaining AgNO 3 Reducing silver ions in the solution into silver simple substance, simultaneously introducing carbon dioxide into the solution at a flow rate of 22sccm, and introducingHeating the solution for 25min, removing carbon dioxide and ammonia gas in the solution, and performing solid-liquid separation to obtain separated solids which are silver coarse grains;
adding the silver coarse particles obtained in the step two into an alcohol dispersion solution, and stirring and reacting for 2 hours to obtain silver slurry dispersed by 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 slurry, wherein the adding amount of the dispersing agent accounts for 0.33% of the weight of the silver coarse particles, and stirring and dispersing the silver coarse particles for 12 hours to obtain silver dispersion slurry; the preparation method of the alcohol dispersion solution comprises the following steps: 200g of polyethylene glycol-400 liquid is weighed, the polyethylene glycol-400 liquid is poured into 1200mL of methanol, ultrasonic dispersion is carried out for 20min, and the ultrasonic frequency is 2.5kHz, so as 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 150mL, mixing the citric acid, the glycol and 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 particles is 3:1;
The preparation method of the dispersing agent 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 70 ℃, then performing ultrasonic dispersion with the frequency of 3kHz and the dispersion time of 15min to obtain dispersion slurry;
and S32, filtering the dispersion slurry obtained in the step S31, and vacuum drying insoluble matters obtained by filtering 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 and 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 crushed silver powder by using a mixed dispersing agent of gelatin and Arabic gum, and carrying out surface treatment on the secondarily dispersed silver powder by using a surfactant, wherein the specific method comprises the following steps of:
s41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, wherein the concentration of the ammonia water is 0.92g/mL, the volume of the ammonia water is 2800mL, and stirring and mixing to obtain silver slurry A; mixing 2g of gelatin and Arabic gum, pouring into the silver slurry A, and performing ultrasonic dispersion for 25min at an ultrasonic frequency of 4kHz to obtain secondary dispersion silver slurry;
S42, adding 0.3g of surfactant into the secondary dispersion silver slurry, stirring for 30min at 30 ℃ at the stirring speed of 200r/min, and performing surface active treatment on silver powder particles to obtain surface active treated silver slurry;
step S43, evaporating and concentrating the silver slurry subjected to surface activity treatment, washing the evaporated and concentrated silver slurry by using deionized water, and carrying out solid-liquid separation to obtain nano silver powder;
and S44, drying the nano silver powder in a mixed gas of nitrogen and argon at a drying temperature of 50 ℃ until the water is evaporated completely, and thus obtaining the nano silver powder.
Wherein the mass ratio of the gelatin to the acacia is 1:2;
the components of the surfactant comprise dodecanoic acid, oleic acid, stearic acid and octanoic acid, wherein the mass ratio of the dodecanoic acid, the oleic acid, the stearic acid and the octanoic acid is 1:1:1.3:0.2.
Comparative example 2
The preparation method of the nano silver powder for preparing the silver electrode on the back side of the solar cell comprises the following steps:
step one, agNO with the concentration of 200g/L is added to the volume of 2.7L 3 Adding alkaline dispersion liquid into the solution to regulate AgNO 3 The pH value of the solution is 8, and a silver ammonia solution is obtained, wherein the alkaline dispersion liquid is formed by mixing NaOH solution with the mass fraction of 30% and 0.92g/mL ammonia water, 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 for 1h at a rotating speed of 20r/min, standing for reaction for 1.2h, and obtaining AgNO 3 Reducing silver ions in the solution into silver simple substance, simultaneously introducing carbon dioxide into the solution at a flow rate of 22sccm for 25min, heating the solution, and removing the silver simple substanceSeparating carbon dioxide and ammonia gas, and carrying out solid-liquid separation, wherein the separated solids are silver coarse grains;
adding the silver coarse particles obtained in the step two into an alcohol dispersion solution, and stirring and reacting for 2 hours to obtain silver slurry dispersed by 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 slurry, wherein the adding amount of the dispersing agent accounts for 0.33% of the weight of the silver coarse particles, and stirring and dispersing the silver coarse particles for 12 hours to obtain silver dispersion slurry; the preparation method of the alcohol dispersion solution comprises the following steps: 200g of polyethylene glycol-400 liquid is weighed, the polyethylene glycol-400 liquid is poured into 1200mL of methanol, ultrasonic dispersion is carried out for 20min, and the ultrasonic frequency is 2.5kHz, so as 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 150mL, mixing the citric acid, the glycol and 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 particles is 3:1;
The preparation method of the dispersing agent 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 70 ℃, then performing ultrasonic dispersion with the frequency of 3kHz and the dispersion time of 15min to obtain dispersion slurry;
and S32, filtering the dispersion slurry obtained in the step S31, and vacuum drying insoluble matters obtained by filtering 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 and 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 silver powder, and the specific method comprises the following steps:
s41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, wherein the concentration of the ammonia water is 0.92g/mL, the volume of the ammonia water is 2800mL, and stirring and mixing to obtain silver slurry A;
s42, adding 0.3g of surfactant into the silver slurry A, stirring for 30min at 30 ℃ at the stirring speed of 200r/min, and performing surface activity treatment on silver powder particles to obtain surface activity treated silver slurry;
Step S43, evaporating and concentrating the silver slurry subjected to surface activity treatment, washing the evaporated and concentrated silver slurry by using deionized water, and carrying out solid-liquid separation to obtain nano silver powder;
and S44, drying the nano silver powder in a mixed gas of nitrogen and argon at a drying temperature of 50 ℃ until the water is evaporated completely, and thus obtaining the nano silver powder.
The components of the surfactant comprise dodecanoic acid, oleic acid, stearic acid and octanoic acid, wherein the mass ratio of the dodecanoic acid, the oleic acid, the stearic acid and the octanoic acid is 1:1:1.3:0.2.
Comparative example 3
The preparation method of the nano silver powder for preparing the silver electrode on the back side of the solar cell comprises the following steps:
step one, agNO with the concentration of 200g/L is added to the volume of 2.7L 3 Adding alkaline dispersion liquid into the solution to regulate AgNO 3 The pH value of the solution is 8, and a silver ammonia solution is obtained, wherein the alkaline dispersion liquid is formed by mixing NaOH solution with the mass fraction of 30% and 0.92g/mL ammonia water, 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 for 1h at a rotating speed of 20r/min, standing for reaction for 1.2h, and obtaining AgNO 3 Reducing silver ions in the solution into silver simple substance, 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 carrying out solid-liquid separation, wherein the separated solids are silver coarse particles;
Adding the silver coarse particles obtained in the step two into an alcohol dispersion solution, and stirring and reacting for 2 hours to obtain silver slurry dispersed by 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 slurry, wherein the adding amount of the dispersing agent accounts for 0.33% of the weight of the silver coarse particles, and stirring and dispersing the silver coarse particles for 12 hours to obtain silver dispersion slurry; the preparation method of the alcohol dispersion solution comprises the following steps: 200g of polyethylene glycol-400 liquid is weighed, the polyethylene glycol-400 liquid is poured into 1200mL of methanol, ultrasonic dispersion is carried out for 20min, and the ultrasonic frequency is 2.5kHz, so as 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 150mL, mixing the citric acid, the glycol and 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 particles is 3:1;
the preparation method of the dispersing agent 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 70 ℃, then performing ultrasonic dispersion with the frequency of 3kHz and the dispersion time of 15min to obtain dispersion slurry;
And S32, filtering the dispersion slurry obtained in the step S31, and vacuum drying insoluble matters obtained by filtering 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 and 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 of:
s41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, wherein the concentration of the ammonia water is 0.92g/mL, the volume of the ammonia water is 2800mL, and stirring and mixing to obtain silver slurry A; mixing 2g of gelatin and modified Arabic gum, pouring into the silver slurry A, and performing ultrasonic dispersion for 25min at an ultrasonic frequency of 4kHz to obtain secondary dispersion silver slurry;
step S42, evaporating and concentrating the silver slurry subjected to the secondary dispersion treatment, washing the evaporated and concentrated silver slurry by using deionized water, and carrying out solid-liquid separation to obtain nano silver powder;
and S44, drying the nano silver powder in a mixed gas of nitrogen and argon at a drying temperature of 50 ℃ until the water is evaporated completely, and thus obtaining the nano silver powder.
Wherein the mass ratio of the gelatin to the modified Arabic gum is 1:2, and the modification method of the modified Arabic gum is as follows: slowly adding octenyl succinic anhydride into a acacia solution, heating the acacia solution to 60 ℃, carrying out esterification reaction on the octenyl succinic anhydride and acacia for 40min, and drying after the reaction is finished to obtain modified acacia.
Comparative example 4
The preparation method of the nano silver powder for preparing the silver electrode on the back side of the solar cell comprises the following steps:
step one, agNO with the concentration of 200g/L is added to the volume of 2.7L 3 Adding alkaline dispersion liquid into the solution to regulate AgNO 3 The pH value of the solution is 8, and a silver ammonia solution is obtained, wherein the alkaline dispersion liquid is formed by mixing NaOH solution with the mass fraction of 30% and 0.92g/mL ammonia water, 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 for 1h at a rotating speed of 20r/min, standing for reaction for 1.2h, and obtaining AgNO 3 Reducing silver ions in the solution into silver simple substance, 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 carrying out solid-liquid separation, wherein the separated solids are silver coarse particles;
adding the silver coarse particles obtained in the step two into an alcohol dispersion solution, and stirring and reacting for 2 hours to obtain silver slurry dispersed by 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 slurry, wherein the adding amount of the dispersing agent accounts for 0.33% of the weight of the silver coarse particles, and stirring and dispersing the silver coarse particles for 12 hours to obtain silver dispersion slurry; the preparation method of the alcohol dispersion solution comprises the following steps: 200g of polyethylene glycol-400 liquid is weighed, the polyethylene glycol-400 liquid is poured into 1200mL of methanol, ultrasonic dispersion is carried out for 20min, and the ultrasonic frequency is 2.5kHz, so as 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 150mL, mixing the citric acid, the glycol and 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 particles is 3:1;
The preparation method of the dispersing agent 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 70 ℃, then performing ultrasonic dispersion with the frequency of 3kHz and the dispersion time of 15min to obtain dispersion slurry;
and S32, filtering the dispersion slurry obtained in the step S31, and vacuum drying insoluble matters obtained by filtering 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 and crushing on the silver dispersion slurry obtained in the step three, wherein a ball milling medium is ethylene glycol, and thus silver powder is obtained.
100g of the nano silver powder 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 respective particle diameters, specific surface areas, viscosities and tap densities were measured to obtain the following table:
Figure BDA0003480017750000161
from the above table data, it can be seen that: the ratio of the particle diameter of the nano silver powder prepared in example 1 to the particle diameter of the nano silver powder prepared in example 2 to the particle diameter of the nano silver powder prepared in example 309nm to the particle diameter of the nano silver powder prepared in example 3 to the particle diameter of the nano silver powder prepared in example 312nm to the particle diameter of the nano silver powder prepared in example 3 to the particle diameter of the nano silver powder prepared in example 315nm to the nano silver powder prepared in example 3 to the nano silver powder prepared in example 0.61m 2 /g and 0.61m 2 Viscosity of 950 and 950 or more, tap density of 6.17g/mL and 6.17g/mL is more than; the particle size distribution and specific surface area, viscosity and tap density of the nano silver powder prepared by the preparation method provided by the invention are all better than those of the nano silver powder prepared by 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; wherein, in the process of preparing the nano silver powder, the gelatin and the modified Arabic gum are not used for carrying out secondary dispersion on silver slurry in the comparative example 1; comparative example 2 in the process of preparing nano silver powder, the silver slurry was secondarily dispersed without using a dispersing agent; comparative example 3 in the process of preparing nano silver powder, a surface treatment of the silver slurry was not performed using a surfactant; comparative example 4 in the process of preparing the nano silver powder, the nano silver powder dispersed and pulverized for the first time was not subjected to the secondary dispersion and the surface treatment.
The number of equipment and the scale of processing described herein are intended to simplify the description of the present invention. Applications, modifications and variations of the present invention will be readily apparent to those skilled in the art.
Although embodiments of the present invention have been disclosed above, it is not limited to the details and embodiments shown and described, it is well suited to various fields of use for which the invention would be readily apparent to those skilled in the art, and accordingly, the invention is not limited to the specific details and illustrations shown and described herein, without departing from the general concepts defined in the claims and their equivalents.

Claims (7)

1. The preparation method of the nano silver powder for preparing the silver electrode on the back surface of the solar cell is characterized by comprising the following steps of:
step one, agNO is oriented to 3 Adding alkaline dispersion liquid into the solution to regulate AgNO 3 The pH value of the solution is used for obtaining silver-ammonia solution;
step two, adding a reducing agent into the silver ammonia solution obtained in the step one, stirring for reaction, and carrying out AgNO reaction 3 Reducing silver ions in the solution into silver simple substances, and carrying out solid-liquid separation, wherein the separated solids are silver coarse grains;
adding the silver coarse particles obtained in the step two into an alcohol dispersion solution, and stirring and reacting for 2-5 hours to obtain silver slurry dispersed by 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 slurry, stirring and carrying out dispersion reaction for 12-20 hours to obtain silver dispersion slurry;
Step four, carrying out centrifugal suction filtration, washing, vacuum drying, ball milling and 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 nano silver powder;
adding a reducing agent into the silver-ammonia solution, stirring at a speed of 20r/min, standing for 1-3 h after stirring for 1h, introducing carbon dioxide into the solution at a flow rate of 22sccm for 20-30 min, and finally heating the solution to remove carbon dioxide and ammonia in the solution;
the dispersing agent used in the second dispersion of silver powder is a mixed dispersing agent 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 the acacia solution, heating the acacia solution to 60-65 ℃, carrying out esterification reaction on the octenyl succinic anhydride and the acacia for 40-50 min, and drying after the reaction is finished to obtain the modified acacia.
2. The method for preparing nano silver powder for preparing back silver electrode of solar cell according to claim 1, wherein AgNO in the step one 3 The 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 regulated after the alkaline dispersion liquid is added 3 The pH of the solution is 8-13.
3. The method for preparing nano silver powder for preparing the back silver electrode of the solar cell 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 formaldehyde to silver nitrate is greater than 1:2; when the reducing agent is sodium borohydride, the molar ratio of sodium borohydride to silver nitrate is greater than 1:4.
4. The method for preparing nano silver powder for preparing a back silver electrode of a solar cell according to claim 1, wherein the method for preparing the alcohol dispersion solution used in the third step comprises the steps of: 200g of polyethylene glycol-400 liquid is weighed, the polyethylene glycol-400 liquid is poured into 1200-1700 mL of methanol, ultrasonic dispersion is carried out for 20min, the ultrasonic frequency is 2.5-5 kHz, and a mixed alcohol solution A is obtained; adding citric acid and ethylene glycol into the mixed alcohol solution A, wherein the volume ratio of the citric acid to the ethylene glycol is 1:1, the volume of the ethylene glycol is 150-300 mL, mixing the citric acid, the ethylene glycol and the mixed alcohol solution A, heating to 70-85 ℃, and preserving heat 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.
5. The method for preparing nano silver powder for preparing a silver electrode on a back surface of a solar cell according to claim 1, wherein the dispersant in the third step accounts for 0.33% of the weight of the coarse silver particles, and the method for preparing the dispersant comprises the following steps:
step 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 70 ℃, then performing ultrasonic dispersion with the frequency of 3kHz and the dispersion time of 15min to obtain dispersion slurry;
and S32, filtering the dispersion slurry obtained in the step S31, and vacuum drying insoluble matters obtained by filtering for 24 hours at the drying temperature of 80-110 ℃ to obtain the dispersing agent.
6. The method for preparing nano silver powder for preparing the silver electrode on the back surface of the solar cell according to claim 1, wherein in the fourth step, the reagent for carrying out surface treatment on the silver powder is a surfactant, and the components of the surfactant comprise dodecanoic acid, oleic acid, stearic acid and octanoic acid, wherein the mass ratio of the dodecanoic acid, the oleic acid, the stearic acid and the octanoic acid is 1:1:1.3-2:0.2.
7. The method for preparing nano silver powder for preparing a back silver electrode of a solar cell according to claim 6, wherein in the fourth step, the method for secondarily dispersing, surface treating, washing and drying the crushed silver powder comprises:
s41, weighing 108g of crushed silver powder, adding the silver powder into ammonia water, wherein the concentration of the ammonia water is 0.92g/mL, the volume of the ammonia water is 2800mL, and stirring and mixing to obtain silver slurry A; mixing 2g of gelatin and modified Arabic gum, pouring into the silver slurry A, and performing ultrasonic dispersion for 25-70 min at an ultrasonic frequency of 4kHz to obtain secondary dispersion silver slurry;
s42, adding 0.3g of surfactant into the secondary dispersion silver slurry, stirring for 30min at 30-38 ℃ at the stirring speed of 200r/min, and performing surface active treatment on silver powder particles to obtain surface active treated silver slurry;
step S43, evaporating and concentrating the silver slurry subjected to surface activity treatment, washing the evaporated and concentrated silver slurry by using deionized water, and carrying out solid-liquid separation to obtain nano silver powder;
and S44, drying the nano silver powder in a mixed gas of nitrogen and argon at a drying temperature of 50-70 ℃ until the water is evaporated completely, so as to obtain the nano silver powder.
CN202210065472.XA 2022-01-20 2022-01-20 Preparation method of nano silver powder for preparing silver electrode on back of solar cell Active CN114420372B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210065472.XA CN114420372B (en) 2022-01-20 2022-01-20 Preparation method of nano silver powder for preparing silver electrode on back of solar cell

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210065472.XA CN114420372B (en) 2022-01-20 2022-01-20 Preparation method of nano silver powder for preparing silver electrode on back of solar cell

Publications (2)

Publication Number Publication Date
CN114420372A CN114420372A (en) 2022-04-29
CN114420372B true CN114420372B (en) 2023-05-19

Family

ID=81275572

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210065472.XA Active CN114420372B (en) 2022-01-20 2022-01-20 Preparation method of nano silver powder for preparing silver electrode on back of solar cell

Country Status (1)

Country Link
CN (1) CN114420372B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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

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

Also Published As

Publication number Publication date
CN114420372A (en) 2022-04-29

Similar Documents

Publication Publication Date Title
CN114420372B (en) Preparation method of nano silver powder for preparing silver electrode on back of solar cell
CN101716685B (en) Method for preparing spherical superfine silver powder by using chemical reduction method
CN110355380B (en) Preparation method of hexagonal flaky micron-crystal silver powder
US8372178B2 (en) Silver particles and processes for making them
US8231704B2 (en) Silver particles and processes for making them
US20190039142A1 (en) A method for preparing silver powder by using micro-nano bubbles as crystal seeds
CN102248177B (en) Laser-induced method for preparing spherical silver powder
CN103079732A (en) Copper powder for conductive paste and method for manufacturing same
CN112296351B (en) Preparation method of high-tap-density ultrafine silver powder
US20120049133A1 (en) Silver particles and a process for making them
CN101972855A (en) Method for preparing silver micro-powder for high-temperature sintering silver pastes
CN113053561A (en) Low-temperature slurry for heterojunction solar cell with silver-plated copper powder as conductive particles and preparation method thereof
CN116251961A (en) Method for preparing silver powder with assistance of ultrasonic waves, silver powder prepared by method and application of silver powder
CN111590086A (en) Ultrathin flake silver powder with smooth surface and preparation method thereof
CN110449572A (en) The preparation method of the functional silver powder of electric slurry
CN110919028A (en) Preparation method of superfine irregular silver powder
CN113414401B (en) Silver powder of crystalline silicon solar PERC battery silver paste and preparation method thereof
CN114939668A (en) Preparation method of superfine silver powder and silver conductive paste thereof
CN105081343B (en) A kind of manufacture method of conductive silver powder for touch-screen UV type laser engraving silver pastes
CN114192769A (en) Silver powder with flower-like structure and preparation method thereof
CN112974827A (en) Preparation method of spherical silver powder with high tap density and surface wrinkles
CN116174739B (en) Microcrystal nano-sheet aggregation type spheroidal silver powder and preparation method thereof
CN105817646A (en) Preparation method for spherical silver powder high in tap density
CN117182095A (en) Silver palladium alloy powder and preparation method thereof
CN115647353A (en) Preparation method of micron silver powder with high sintering activity

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant