阅读说明：本技术 一种太阳能电池用高分散型银粉和导电银浆的制备方法 (Preparation method of high-dispersion silver powder and conductive silver paste for solar cell ) 是由 赵庆亮 于 2021-09-07 设计创作，主要内容包括：本发明公开了一种太阳能电池用导电银浆的制备方法,包括以下步骤：步骤一：改性凹凸棒土的制备：将凹凸棒土送入到质量分数20%的硫酸中进行酸化,酸化10-20min,然后水洗,再采用100-200℃煅烧10-20min,煅烧结束,自然冷却至室温；步骤二：改性高分散型银粉的制备。本发明导电银浆的制备中采用银基稀土液、改性凹凸棒土、玻璃粉、改进型有机粘接剂、乙基纤维素进行配比而成,银基稀土液采用高分散型的银粉制成,制备的银粉分散性能高,同时与硅灰石溶液反应后,能够将银粉负载在针状的硅灰石上,从而起到导向作用,在与银浆配比中,增强与产品原料的混合反应效率。(The invention discloses a preparation method of conductive silver paste for a solar cell, which comprises the following steps: the method comprises the following steps: preparing modified attapulgite: delivering the attapulgite into sulfuric acid with the mass fraction of 20% for acidification for 10-20min, then washing with water, calcining at the temperature of 100-200 ℃ for 10-20min, and naturally cooling to room temperature after the calcination is finished; step two: and preparing the modified high-dispersion silver powder. The conductive silver paste is prepared by proportioning the silver-based rare earth liquid, the modified attapulgite, the glass powder, the improved organic adhesive and the ethyl cellulose, wherein the silver-based rare earth liquid is prepared from the highly-dispersed silver powder, the prepared silver powder has high dispersibility, and can be loaded on needle-shaped wollastonite after reacting with the wollastonite solution, so that the conductive silver paste plays a guiding role, and the mixing reaction efficiency with product raw materials is enhanced in proportioning with the silver paste.)

1. The preparation method of the conductive silver paste for the solar cell is characterized by comprising the following steps of:

the method comprises the following steps: preparing modified attapulgite: delivering the attapulgite into sulfuric acid with the mass fraction of 20% for acidification for 10-20min, then washing with water, calcining at the temperature of 100-200 ℃ for 10-20min, and naturally cooling to room temperature after the calcination is finished;

step two: preparing modified high-dispersion silver powder: mixing the high-dispersion silver powder and the modified bentonite according to the weight ratio of 1:2, and then sending the mixture into an acetone solvent for ultrasonic dispersion, wherein the ultrasonic power is 20-30%, and the ultrasonic time is 10-20min, so as to obtain the modified high-dispersion silver powder; wherein the modified bentonite adopts bentonite to react for 20-30min at the temperature of 100-150 ℃, and then is naturally cooled to the room temperature;

step three: preparing a silver-based rare earth liquid: taking the modified high-dispersion silver powder as a matrix, adding Y, Tm rare earth metal elements, and proportioning to form a silver-based rare earth material, wherein the mass ratio of the modified high-dispersion silver powder to Y, Tm rare earth is 98:1.2: 0.8; then mixing the silver-based rare earth material with 70% concentrated hydrochloric acid according to the weight ratio of 1:3 to prepare silver-based rare earth liquid;

step four: weighing 10-20 parts of silver-based rare earth liquid, 5-10 parts of modified attapulgite, 1-5 parts of glass powder, 2-8 parts of improved organic adhesive and 1-5 parts of ethyl cellulose;

step five: and sequentially adding the raw materials in the step two into a stirrer for mixing, wherein the mixing rotating speed is 100-500r/min, the mixing time is 10-20min, and after the mixing is finished, obtaining the conductive silver paste.

2. The method for preparing the conductive silver paste for the solar cell according to claim 1, wherein the improved organic binder is prepared by the following steps:

s1: mixing melamine and paraformaldehyde according to a weight ratio of 1:2, adding sodium hydroxide alkali, adjusting the pH to 9.0, reacting at 75-85 ℃ for 10-20min, finally adding terephthalaldehyde, and continuing to react for 5-10min to obtain a melamine formaldehyde agent;

s2: preparation of improved cyclodextrin: carrying out double-property enhancement reaction on the cyclodextrin for 10-20min, and finishing the reaction to obtain improved cyclodextrin;

s3: the rosin resin and the improved cyclodextrin are mixed and proportioned according to the weight ratio of 5:1, and then the mixture is mixed and reacted with the melamine formaldehyde agent accounting for 20-30% of the total amount of the rosin resin to obtain the improved organic adhesive.

3. The method for preparing the conductive silver paste for the solar cell according to claim 2, wherein the specific reaction steps of the double reinforcing reaction are as follows: and (3) feeding the cyclodextrin into an inorganic agent for reaction for 10-20min, then feeding the cyclodextrin into an organic agent for reaction for 10-20min, wherein the reaction temperature is 65-75 ℃, and after the reaction is finished, washing and drying the cyclodextrin.

4. The method for preparing the conductive silver paste for the solar cell according to claim 3, wherein the inorganic agent is a hydrogen peroxide-hydrochloric acid mixed solution; the organic agent is a coupling agent KH 560.

5. The method for preparing the conductive silver paste for the solar cell according to claim 4, wherein the method for preparing the hydrogen peroxide-hydrochloric acid mixed solution comprises the following steps: mixing and stirring uniformly a hydrogen peroxide solution with the mass concentration of 1.0% and a hydrochloric acid solution with the molar concentration of 0.15 mol/L according to the mass ratio of 1:3 to obtain the hydrogen peroxide/hydrochloric acid composite material.

6. The method for preparing conductive silver paste for solar cell according to claim 2, wherein the reaction temperature in S3 is 75-85 ℃, and the reaction rotation speed is 300-400 r/min.

7. The method for preparing the conductive silver paste for the solar cell according to claim 6, wherein the reaction temperature in the step S3 is 80 ℃ and the reaction speed is 350 r/min.

8. A preparation method of high-dispersion silver powder for a solar cell is characterized by comprising the following steps:

step one, adding a silver nitrate aqueous solution with the concentration of 0.01-0.05mol/L into a lauryl alcohol ether sodium sulfate solution with the concentration of 0.2g/L, then mixing and stirring the mixture with sodium hydrosulfite with the weight of 10-20% of the silver nitrate aqueous solution for 10-20min at the stirring speed of 200r/min, and then adding sodium hydroxide to adjust the pH value of the solution to obtain 10.0-11.0 to obtain a primary material;

step two, sending the primary material into a sodium alginate solution with the mass fraction of 30-50% for ultrasonic dispersion for 10-20min, wherein the dispersion power is 100 and 200w, after the dispersion is finished, washing with water, and drying to obtain a primary silver powder material;

and step three, feeding the silver powder primary material into the improved wollastonite solution, stirring for 10-20min at the stirring speed of 100-200r/min, carrying out hot-pressing reaction after stirring is finished, and drying after hot-pressing is finished to obtain the high-dispersion silver powder.

9. The method for preparing highly dispersible silver powder for solar cell according to claim 8, wherein the modified wollastonite solution is prepared by the following steps:

s1, the wollastonite is firstly sent into a grinding machine to be ground for 10 to 20min, and the grinding speed is 100-;

s2: then heating to 150-;

s3: and (3) dispersing the mixture in active liquid of 10-20 parts of hydrochloric acid and 1-5 parts of sodium lauryl sulfate for 10-20min at the dispersion speed of 100r/min to obtain the improved wollastonite solution.

10. The method for preparing highly dispersed silver powder for solar cell as claimed in claim 8, wherein the hot pressing reaction is carried out for 10-20min at a pressure of 1-5MPa and a temperature of 120-150 ℃.

Technical Field

The invention relates to the technical field of solar cell silver powder, in particular to a preparation method of high-dispersion silver powder and conductive silver paste for a solar cell.

Background

A lithium solar cell is a device that directly converts light energy into electrical energy by a photoelectric effect or a photochemical effect. The voltage and the current can be output instantly as long as the lamp is illuminated. Physically called solar photovoltaic, referred to as photovoltaic for short. Thin film solar cells operating with the photoelectric effect are the mainstream, while wet solar cells operating with the photochemical effect are still in the germination stage.

The conductive silver paste for the solar cell has higher requirements on the form, the granularity and the distribution uniformity of the silver powder, the known types of the silver powder comprise spherical, rod-shaped, flaky, net-shaped, dendritic and the like, and the spherical silver powder is generally most widely applied to the photovoltaic field, particularly the front silver paste of the solar cell, so that the requirements on printing and conductivity are more easily met.

The existing silver powder preparation process is more conventional, has poor dispersibility, is applied to conductive silver paste, has poor matching performance with silver paste raw materials, and meanwhile, the organic raw materials, glass powder and silver powder in the existing silver paste are mixed in proportion, so that the overall performances of the product such as conductivity are influenced.

Disclosure of Invention

In view of the defects of the prior art, the present invention aims to provide a method for preparing highly dispersed silver powder and conductive silver paste for solar cells, so as to solve the problems in the background art.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the invention provides a preparation method of conductive silver paste, which comprises the following steps:

the method comprises the following steps: preparing modified attapulgite: delivering the attapulgite into sulfuric acid with the mass fraction of 20% for acidification for 10-20min, then washing with water, calcining at the temperature of 100-200 ℃ for 10-20min, and naturally cooling to room temperature after the calcination is finished;

step two: preparing modified high-dispersion silver powder: mixing the high-dispersion silver powder and the modified bentonite according to the weight ratio of 1:2, and then sending the mixture into an acetone solvent for ultrasonic dispersion, wherein the ultrasonic power is 20-30%, and the ultrasonic time is 10-20min, so as to obtain the modified high-dispersion silver powder; wherein the modified bentonite adopts bentonite to react for 20-30min at the temperature of 100-150 ℃, and then is naturally cooled to the room temperature;

step three: preparing a silver-based rare earth liquid: taking the modified high-dispersion silver powder as a matrix, adding Y, Tm rare earth metal elements, and proportioning to form a silver-based rare earth material, wherein the mass ratio of the modified high-dispersion silver powder to Y, Tm rare earth is 98:1.2: 0.8; then mixing the silver-based rare earth material with 70% concentrated hydrochloric acid according to the weight ratio of 1:3 to prepare silver-based rare earth liquid;

step four: weighing 10-20 parts of silver-based rare earth liquid, 5-10 parts of modified attapulgite, 1-5 parts of glass powder, 2-8 parts of improved organic adhesive and 1-5 parts of ethyl cellulose;

step five: and sequentially adding the raw materials in the step two into a stirrer for mixing, wherein the mixing rotating speed is 100-500r/min, the mixing time is 10-20min, and after the mixing is finished, obtaining the conductive silver paste.

Preferably, the preparation method of the improved organic adhesive comprises the following steps:

s1: mixing melamine and paraformaldehyde according to a weight ratio of 1:2, adding sodium hydroxide alkali, adjusting the pH to 9.0, reacting at 75-85 ℃ for 10-20min, finally adding terephthalaldehyde, and continuing to react for 5-10min to obtain a melamine formaldehyde agent;

s2: preparation of improved cyclodextrin: carrying out double-property enhancement reaction on the cyclodextrin for 10-20min, and finishing the reaction to obtain improved cyclodextrin;

s3: the rosin resin and the improved cyclodextrin are mixed and proportioned according to the weight ratio of 5:1, and then the mixture is mixed and reacted with the melamine formaldehyde agent accounting for 20-30% of the total amount of the rosin resin to obtain the improved organic adhesive.

Preferably, the specific reaction steps of the double-property reinforced reaction are as follows: and (3) feeding the cyclodextrin into an inorganic agent for reaction for 10-20min, then feeding the cyclodextrin into an organic agent for reaction for 10-20min, wherein the reaction temperature is 65-75 ℃, and after the reaction is finished, washing and drying the cyclodextrin.

Preferably, the inorganic agent is a hydrogen peroxide-hydrochloric acid mixed solution; the organic agent is a coupling agent KH 560.

Preferably, the preparation method of the hydrogen peroxide-hydrochloric acid mixed solution comprises the following steps: mixing and stirring uniformly a hydrogen peroxide solution with the mass concentration of 1.0% and a hydrochloric acid solution with the molar concentration of 0.15 mol/L according to the mass ratio of 1:3 to obtain the hydrogen peroxide/hydrochloric acid composite material.

Preferably, the reaction temperature in the S3 is 75-85 ℃, and the reaction speed is 300-400 r/min.

Preferably, the reaction temperature in the S3 is 80 ℃, and the reaction speed is 350 r/min.

A preparation method of high-dispersion silver powder for a solar cell specifically comprises the following steps:

step one, adding a silver nitrate aqueous solution with the concentration of 0.01-0.05mol/L into a lauryl alcohol ether sodium sulfate solution with the concentration of 0.2g/L, then mixing and stirring the mixture with sodium hydrosulfite with the weight of 10-20% of the silver nitrate aqueous solution for 10-20min at the stirring speed of 200r/min, and then adding sodium hydroxide to adjust the pH value of the solution to obtain 10.0-11.0 to obtain a primary material;

step two, sending the primary material into a sodium alginate solution with the mass fraction of 30-50% for ultrasonic dispersion for 10-20min, wherein the dispersion power is 100 and 200w, after the dispersion is finished, washing with water, and drying to obtain a primary silver powder material;

and step three, feeding the silver powder primary material into the improved wollastonite solution, stirring for 10-20min at the stirring speed of 100-200r/min, carrying out hot-pressing reaction after stirring is finished, and drying after hot-pressing is finished to obtain the high-dispersion silver powder.

Preferably, the specific preparation method of the improved wollastonite solution is as follows:

s1, the wollastonite is firstly sent into a grinding machine to be ground for 10 to 20min, and the grinding speed is 100-;

s2: then heating to 150-;

s3: and (3) dispersing the mixture in active liquid of 10-20 parts of hydrochloric acid and 1-5 parts of sodium lauryl sulfate for 10-20min at the dispersion speed of 100r/min to obtain the improved wollastonite solution.

Preferably, the hot-pressing reaction is carried out for 10-20min, the hot-pressing pressure is 1-5MPa, and the hot-pressing temperature is 120-.

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

the conductive silver paste is prepared by proportioning the silver-based rare earth liquid, the modified attapulgite, the glass powder, the improved organic adhesive and the ethyl cellulose, wherein the silver-based rare earth liquid is prepared from the highly-dispersed silver powder; the improved organic adhesive in the conductive silver paste is prepared by proportioning a melamine formaldehyde agent and a rosin resin, adding improved cyclodextrin, carrying out amphiphilic reaction on the modified cyclodextrin, and having extremely strong organophilic and inorganic performances, so that inorganic raw materials are combined and gathered with glass powder and other raw materials, and the silver-based rare earth liquid is prepared by proportioning highly-dispersed silver powder and modified bentonite, the modified bentonite is thermally activated to form lamellar bentonite, guiding silver powder is inserted into the bentonite lamellar, and is orderly arranged in a silver paste product, and meanwhile, through the addition of the modified attapulgite, the attapulgite has high ionic performance after being modified, so that the conductivity of the product is enhanced, and the added raw materials are reasonably matched to have excellent conductivity and peel strength.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to specific embodiments, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The preparation method of the conductive silver paste of the embodiment comprises the following steps:

the method comprises the following steps: preparing modified attapulgite: delivering the attapulgite into sulfuric acid with the mass fraction of 20% for acidification for 10min, then washing with water, calcining at 100 ℃ for 10min, and naturally cooling to room temperature after calcination;

step two: preparing modified high-dispersion silver powder: mixing the high-dispersion silver powder and the modified bentonite according to the weight ratio of 1:2, and then sending the mixture into an acetone solvent for ultrasonic dispersion, wherein the ultrasonic power is 20%, and the ultrasonic time is 10min, so as to obtain the modified high-dispersion silver powder;

step three: preparing a silver-based rare earth liquid: taking the modified high-dispersion silver powder as a matrix, adding Y, Tm rare earth metal elements, and proportioning to form a silver-based rare earth material, wherein the mass ratio of the modified high-dispersion silver powder to Y, Tm rare earth is 98:1.2: 0.8; then mixing the silver-based rare earth material with 70% concentrated hydrochloric acid according to the weight ratio of 1:3 to prepare silver-based rare earth liquid;

step four: weighing 10 parts of silver-based rare earth liquid, 5 parts of modified attapulgite, 1 part of glass powder, 2 parts of improved organic adhesive and 1 part of ethyl cellulose;

step five: and D, sequentially adding the raw materials in the step two into a stirrer for mixing at the mixing speed of 100r/min for 10min, and obtaining the conductive silver paste after mixing.

The preparation method of the improved organic adhesive of the embodiment comprises the following steps:

s1: mixing melamine and paraformaldehyde according to a weight ratio of 1:2, then adding sodium hydroxide alkali, adjusting the pH to 9.0, reacting at 75 ℃ for 10min, finally adding terephthalaldehyde, and continuing to react for 5min to obtain a melamine formaldehyde agent;

s2: preparation of improved cyclodextrin: carrying out double-property enhancement reaction on the cyclodextrin for 10min, and finishing the reaction to obtain improved cyclodextrin;

s3: the rosin resin and the improved cyclodextrin are mixed and proportioned according to the weight ratio of 5:1, and then the mixture is mixed and reacted with the melamine formaldehyde agent accounting for 20% of the total amount of the rosin resin to obtain the improved organic adhesive.

The specific reaction steps of the dual-property enhancement reaction in this example are: and (3) feeding the cyclodextrin into an inorganic agent for reaction for 10min, then feeding the cyclodextrin into an organic agent for reaction for 10min, wherein the reaction temperature is 65 ℃, and after the reaction is finished, washing and drying.

The inorganic agent in the embodiment is a hydrogen peroxide-hydrochloric acid mixed solution; the organic agent is a coupling agent KH 560.

The preparation method of the hydrogen peroxide-hydrochloric acid mixed solution of the embodiment comprises the following steps: mixing and stirring uniformly a hydrogen peroxide solution with the mass concentration of 1.0% and a hydrochloric acid solution with the molar concentration of 0.15 mol/L according to the mass ratio of 1:3 to obtain the hydrogen peroxide/hydrochloric acid composite material.

In the present example, the reaction temperature in S3 was 75 ℃ and the reaction rate was 300 r/min.

In the preparation method of the highly dispersed silver powder for a solar cell of the embodiment, the preparation method of the highly dispersed silver powder specifically includes the following steps:

adding a silver nitrate aqueous solution with the concentration of 0.01mol/L into a lauryl alcohol ether sodium sulfate solution with the concentration of 0.2g/L, then mixing and stirring the silver nitrate aqueous solution and sodium hydrosulfite with the weight of 10% of the silver nitrate aqueous solution for 10min at the stirring speed of 100r/min, and then adding sodium hydroxide to adjust the pH value of the solution to 10.0 to obtain a primary material;

step two, sending the primary material into a sodium alginate solution with the mass fraction of 30% for ultrasonic dispersion for 10min, wherein the dispersion power is 100w, and after the dispersion is finished, washing with water and drying to obtain a primary silver powder material;

and step three, feeding the silver powder primary material into the improved wollastonite solution, stirring for 10min at the stirring speed of 100r/min, finishing stirring, then carrying out hot-pressing reaction, finishing hot pressing, and drying to obtain the high-dispersion silver powder.

The specific preparation method of the improved wollastonite solution of this example is as follows:

s1, firstly, feeding wollastonite into a grinder to grind for 10min, wherein the grinding speed is 100 r/min;

s2: then heating to 15 ℃, reacting for 5min, and then cooling to 40 ℃;

s3: and (3) dispersing the mixture in active liquid of 10 parts of hydrochloric acid and 1 part of sodium lauryl sulfate at the dispersion speed of 100r/min for 10min to obtain the improved wollastonite solution.

The hot-pressing reaction of the present example was carried out for 10min at a hot-pressing pressure of 1MPa and a hot-pressing temperature of 120 ℃.

Example 2

The preparation method of the conductive silver paste of the embodiment comprises the following steps:

the method comprises the following steps: preparing modified attapulgite: delivering the attapulgite into sulfuric acid with the mass fraction of 20% for acidification for 15min, then washing with water, calcining at 150 ℃ for 15min, and naturally cooling to room temperature after calcination;

step two: preparing modified high-dispersion silver powder: mixing the high-dispersion silver powder and the modified bentonite according to the weight ratio of 1:2, and then sending the mixture into an acetone solvent for ultrasonic dispersion, wherein the ultrasonic power is 20-30%, and the ultrasonic time is 10-20min, so as to obtain the modified high-dispersion silver powder;

step three: preparing a silver-based rare earth liquid: taking the modified high-dispersion silver powder as a matrix, adding Y, Tm rare earth metal elements, and proportioning to form a silver-based rare earth material, wherein the mass ratio of the modified high-dispersion silver powder to Y, Tm rare earth is 98:1.2: 0.8; then mixing the silver-based rare earth material with 70% concentrated hydrochloric acid according to the weight ratio of 1:3 to prepare silver-based rare earth liquid;

step four: weighing 15 parts of silver-based rare earth liquid, 7.5 parts of modified attapulgite, 3 parts of glass powder, 5 parts of improved organic adhesive and 3 parts of ethyl cellulose;

step five: and D, sequentially adding the raw materials in the step two into a stirrer for mixing at the mixing speed of 500r/min for 20min, and obtaining the conductive silver paste after mixing.

The preparation method of the improved organic adhesive of the embodiment comprises the following steps:

s1: mixing melamine and paraformaldehyde according to a weight ratio of 1:2, then adding sodium hydroxide alkali, adjusting the pH to 9.0, reacting at 85 ℃ for 20min, finally adding terephthalaldehyde, and continuing to react for 10min to obtain a melamine formaldehyde agent;

s2: preparation of improved cyclodextrin: carrying out double-property enhancement reaction on the cyclodextrin for 20min, and finishing the reaction to obtain improved cyclodextrin;

s3: the rosin resin and the improved cyclodextrin are mixed and proportioned according to the weight ratio of 5:1, and then the mixture is mixed and reacted with melamine formaldehyde agent accounting for 30% of the total amount of the rosin resin to obtain the improved organic adhesive.

The specific reaction steps of the dual-property enhancement reaction in this example are: and (3) feeding the cyclodextrin into an inorganic agent for reaction for 20min, then feeding the cyclodextrin into an organic agent for reaction for 20min, wherein the reaction temperature is 75 ℃, and after the reaction is finished, washing and drying.

The inorganic agent in the embodiment is a hydrogen peroxide-hydrochloric acid mixed solution; the organic agent is a coupling agent KH 560.

The preparation method of the hydrogen peroxide-hydrochloric acid mixed solution of the embodiment comprises the following steps: mixing and stirring uniformly a hydrogen peroxide solution with the mass concentration of 1.0% and a hydrochloric acid solution with the molar concentration of 0.15 mol/L according to the mass ratio of 1:3 to obtain the hydrogen peroxide/hydrochloric acid composite material.

In the present example, the reaction temperature in S3 was 85 ℃ and the reaction rate was 400 r/min.

In the preparation method of the highly dispersed silver powder for a solar cell of the embodiment, the preparation method of the highly dispersed silver powder specifically includes the following steps:

step one, adding a silver nitrate aqueous solution with the concentration of 0.05mol/L into a lauryl alcohol ether sodium sulfate solution with the concentration of 0.2g/L, then mixing and stirring the silver nitrate aqueous solution and sodium hydrosulfite with the weight of 20% of the silver nitrate aqueous solution for 20min at the stirring speed of 200r/min, and then adding sodium hydroxide to adjust the pH value of the solution to 11.0 to obtain a primary material;

step two, sending the primary material into a sodium alginate solution with the mass fraction of 50%, performing ultrasonic dispersion for 20min, finishing dispersion, then washing with water, and drying to obtain a primary silver powder material, wherein the dispersion power is 200 w;

and step three, feeding the silver powder primary material into the improved wollastonite solution, stirring for 20min at the stirring speed of 200r/min, finishing stirring, then carrying out hot-pressing reaction, finishing hot pressing, and drying to obtain the high-dispersion silver powder.

The specific preparation method of the improved wollastonite solution of this example is as follows:

s1, the wollastonite is firstly sent into a grinder to be ground for 20min, and the grinding speed is 500 r/min;

s2: then heating to 200 ℃, reacting for 5min, and then cooling to 50 ℃;

s3: and (3) dispersing the mixture in active liquid of 20 parts of hydrochloric acid and 5 parts of sodium lauryl sulfate for 20min at the dispersion speed of 100r/min to obtain the improved wollastonite solution.

The hot-pressing reaction of the present example was carried out for 20min at a hot-pressing pressure of 5MPa and a hot-pressing temperature of 150 ℃.

Example 3

The preparation method of the conductive silver paste of the embodiment comprises the following steps:

the method comprises the following steps: preparing modified attapulgite: delivering the attapulgite into sulfuric acid with the mass fraction of 20% for acidification for 15min, then washing with water, calcining at 150 ℃ for 15min, and naturally cooling to room temperature after calcination;

step two: preparing modified high-dispersion silver powder: mixing the high-dispersion silver powder and the modified bentonite according to the weight ratio of 1:2, and then sending the mixture into an acetone solvent for ultrasonic dispersion, wherein the ultrasonic power is 25%, and the ultrasonic time is 15min, so as to obtain the modified high-dispersion silver powder;

step three: preparing a silver-based rare earth liquid: taking the modified high-dispersion silver powder as a matrix, adding Y, Tm rare earth metal elements, and proportioning to form a silver-based rare earth material, wherein the mass ratio of the modified high-dispersion silver powder to Y, Tm rare earth is 98:1.2: 0.8; then mixing the silver-based rare earth material with 70% concentrated hydrochloric acid according to the weight ratio of 1:3 to prepare silver-based rare earth liquid;

step four: weighing 15 parts of silver-based rare earth liquid, 7.5 parts of modified attapulgite, 3 parts of glass powder, 5 parts of improved organic adhesive and 3 parts of ethyl cellulose;

step five: and D, sequentially adding the raw materials in the step two into a stirrer for mixing at the mixing speed of 300r/min for 15min, and obtaining the conductive silver paste after mixing.

The preparation method of the improved organic adhesive of the embodiment comprises the following steps:

s1: mixing melamine and paraformaldehyde according to a weight ratio of 1:2, then adding sodium hydroxide alkali, adjusting the pH to 9.0, reacting for 15min at 80 ℃, finally adding terephthalaldehyde, and continuing to react for 7.5min to obtain a melamine formaldehyde agent;

s2: preparation of improved cyclodextrin: carrying out double-property enhancement reaction on the cyclodextrin for 15min, and finishing the reaction to obtain improved cyclodextrin;

s3: the rosin resin and the improved cyclodextrin are mixed and proportioned according to the weight ratio of 5:1, and then the mixture is mixed and reacted with the melamine formaldehyde agent accounting for 25% of the total amount of the rosin resin to obtain the improved organic adhesive.

The specific reaction steps of the dual-property enhancement reaction in this example are: and (3) feeding the cyclodextrin into an inorganic agent for reaction for 15min, then feeding the cyclodextrin into an organic agent for reaction for 15min, wherein the reaction temperature is 70 ℃, and after the reaction is finished, washing and drying.

The inorganic agent in the embodiment is a hydrogen peroxide-hydrochloric acid mixed solution; the organic agent is a coupling agent KH 560.

The preparation method of the hydrogen peroxide-hydrochloric acid mixed solution of the embodiment comprises the following steps: mixing and stirring uniformly a hydrogen peroxide solution with the mass concentration of 1.0% and a hydrochloric acid solution with the molar concentration of 0.15 mol/L according to the mass ratio of 1:3 to obtain the hydrogen peroxide/hydrochloric acid composite material.

In the present example, the reaction temperature in S3 was 80 ℃ and the reaction rate was 350 r/min.

In the preparation method of the highly dispersed silver powder for a solar cell of the embodiment, the preparation method of the highly dispersed silver powder specifically includes the following steps:

step one, adding a silver nitrate aqueous solution with the concentration of 0.03mol/L into a lauryl alcohol ether sodium sulfate solution with the concentration of 0.2g/L, then mixing and stirring the silver nitrate aqueous solution and sodium hydrosulfite with the weight of 15% of the silver nitrate aqueous solution for 15min at the stirring speed of 150r/min, and then adding sodium hydroxide to adjust the pH value of the solution to 10.5 to obtain a primary material;

step two, sending the primary material into a sodium alginate solution with the mass fraction of 40%, performing ultrasonic dispersion for 15min, finishing dispersion, then washing with water, and drying to obtain a primary silver powder material, wherein the dispersion power is 150 w;

and step three, feeding the silver powder primary material into the improved wollastonite solution, stirring for 15min at the stirring speed of 150r/min, finishing stirring, then carrying out hot-pressing reaction, finishing hot pressing, and drying to obtain the high-dispersion silver powder.

The specific preparation method of the improved wollastonite solution of this example is as follows:

s1, the wollastonite is firstly sent into a grinder to be ground for 15min, and the grinding speed is 300 r/min;

s2: then heating to 175 ℃, reacting for 5min, and then cooling to 45 ℃;

s3: and (3) dispersing the mixture in active liquid of 15 parts of hydrochloric acid and 3 parts of sodium lauryl sulfate for 15min at the dispersion speed of 100r/min to obtain the improved wollastonite solution.

The hot-pressing reaction of the present example was carried out for 15min at a hot-pressing pressure of 3MPa and a hot-pressing temperature of 135 ℃.

Comparative example 1.

Unlike example 3, no modified attapulgite was added.

Comparative example 2.

The difference from example 3 is that no modified bentonite was added in the preparation of the modified high dispersion type silver powder.

Comparative example 3.

The difference from example 3 is that the modified wollastonite solution is not used in the preparation of the high dispersion type silver powder.

Comparative example 4.

The existing silver powder on the market is adopted.

The results of the performance measurements of examples 1-3 and comparative examples 1-4 are as follows:

	peel strength (N/cm)	Resistivity (10)-6Ω.cm)
			Example 1	24	0.63
Example 2	26	0.61
			Example 3	28	0.56
Comparative example 1	20	2.42
			Comparative example 2	18	2.13
Comparative example 3	21	2.56
			Comparative example 4	19	2.72

As shown in examples 1-3 and comparative examples 1-4, the inventive example 3 has significantly improved peel strength and resistivity compared to comparative example 4, and the inventive product has significant peel performance and conductivity.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.