Preparation method of superfine silver powder for frontal silver slurry of photovoltaic cell

Abstract

The invention relates to a preparation method of superfine silver powder for frontal silver slurry of a photovoltaic cell. By introducing graphene oxide timely in a process of synthesizing superfine silver powder by means of a liquid phase reduction method, action between silver and graphene oxide and dispersity of reduced silver particles are improved by means of electrostatic interaction betweenrich oxygen-containing functional groups on the surface of the graphene oxide and silver ions, and meanwhile, the conductivity of the silver powder is improved by means of relatively high electron mobility, so that inhibition of conductivity of the silver particles by a conventional dispersant is overcome. Compared with the prior art, the preparation method has the advantages of simple and easilyoperated process course, good dispersity of silver, high electron mobility, good conductivity and the like.

Description

technical field

[0001] The invention relates to a front silver paste of a solar cell, in particular to a preparation method of ultrafine silver powder for the front silver paste of a photovoltaic cell. Background technique

[0002] With the rapid development of industries such as photovoltaics, microelectronics and the Internet of Things, the demand for ultrafine silver powder as its conductive phase continues to increase. For example, in the front-side silver paste of photovoltaic cells, ultra-fine silver powder as the conductive phase accounts for up to 80%. Generally, the silver powder used in the front-side silver paste of photovoltaic cells needs to have the characteristics of regular shape, narrow particle size distribution, micron or submicron level, good dispersibility, and high tap density. At the same time, in order to avoid the aggregation of silver particles, it is necessary to add a certain amount of dispersant, which reduces the conductivity of silver to a cer...

Examples

Embodiment 1

[0049] (1-1) Disperse 20mg of graphene oxide in 40mL of deionized water to make a concentration of 0.5g L -1 Graphene oxide dispersion, add 50mL of 1g·L -1 Silver nitrate solution (the mass ratio of graphene oxide and silver nitrate is 1:2.5), stirred, and centrifuged to obtain a solid.

[0050] (1-2) Disperse the obtained solid in 100mL of water, and slowly add 40mL of 4g·L after heating up to 90°C -1 Sodium borohydride solution, keep the reaction temperature constant, continue to react for 4 hours, stop heating, filter after cooling to room temperature, wash the filter cake with distilled water and ethanol, and finally dry to obtain graphene loaded with silver seeds.

[0051] (2-1) Disperse the obtained graphene loaded with silver seeds in 10 mL of deionized water to prepare a dispersion of graphene loaded with silver seeds.

[0052] (2-2) Add 10mL of 120g L to the graphene dispersion loaded with silver seeds -1 silver nitrate solution, heated to 90°C, stirred for 1 hour,...

Embodiment 2

[0054] (1-1) Disperse 40mg graphene oxide in 100mL deionized water to make 0.4g L -1 Graphene oxide dispersion, add 80mL1.5g L -1 Silver nitrate solution, stirred, centrifuged.

[0055] (1-2) Disperse the obtained solid in 400mL of deionized water, and slowly add 120mL of 2g·L after heating up to 85°C -1 Sodium borohydride solution, keep the reaction temperature constant, continue to react for 4 hours, stop heating, filter after cooling to room temperature, wash the filter cake with distilled water and ethanol, and finally dry to obtain graphene loaded with silver seeds.

[0056] (2-1) The obtained graphene loaded with silver seeds was dispersed in 40 mL of deionized water to prepare a dispersion of graphene loaded with silver seeds.

[0057] (2-2) Add 10mL of 400g L to the graphene dispersion loaded with silver seeds -1 silver nitrate solution, heated to 85°C, stirred for 1 hour, then slowly added 70mL of 14g·L -1 The sodium borohydride solution, then continue to maintain...

Embodiment 3

[0059] (1-1) Disperse 30mg graphene oxide in 50mL deionized water to make 0.6g L -1 Graphene oxide dispersion, add 120mL0.5g L -1 Silver nitrate solution, stirred, centrifuged.

[0060] (1-2) Disperse the obtained solid in 90mL of deionized water, and slowly add 100mL of 3g·L after heating up to 80°C -1 Sodium borohydride solution, keep the reaction temperature constant, continue to react for 4 hours, stop heating, filter after cooling to room temperature, wash the filter cake with distilled water and ethanol, and finally dry to obtain silver-doped graphene oxide.

[0061] (2-1) The resulting graphene loaded with silver seeds was dispersed in 10 mL of deionized water to prepare a graphene dispersion loaded with silver seeds.

[0062] (2-2) Add 2.5mL of 300g L to the graphene dispersion loaded with silver seeds -1 silver nitrate solution, heated to 80°C, stirred for 1 hour, then slowly added 25mL of 10g·L -1 The sodium borohydride solution, then continue to maintain the tem...

technical field

[0001] The invention relates to a front silver paste of a solar cell, in particular to a preparation method of ultrafine silver powder for the front silver paste of a photovoltaic cell. Background technique

[0002] With the rapid development of industries such as photovoltaics, microelectronics and the Internet of Things, the demand for ultrafine silver powder as its conductive phase continues to increase. For example, in the front-side silver paste of photovoltaic cells, ultra-fine silver powder as the conductive phase accounts for up to 80%. Generally, the silver powder used in the front-side silver paste of photovoltaic cells needs to have the characteristics of regular shape, narrow particle size distribution, micron or submicron level, good dispersibility, and high tap density. At the same time, in order to avoid the aggregation of silver particles, it is necessary to add a certain amount of dispersant, which reduces the conductivity of silver to a cer...

Examples

Embodiment 1

[0049] (1-1) Disperse 20mg of graphene oxide in 40mL of deionized water to make a concentration of 0.5g L -1 Graphene oxide dispersion, add 50mL of 1g·L -1 Silver nitrate solution (the mass ratio of graphene oxide and silver nitrate is 1:2.5), stirred, and centrifuged to obtain a solid.

[0050] (1-2) Disperse the obtained solid in 100mL of water, and slowly add 40mL of 4g·L after heating up to 90°C -1 Sodium borohydride solution, keep the reaction temperature constant, continue to react for 4 hours, stop heating, filter after cooling to room temperature, wash the filter cake with distilled water and ethanol, and finally dry to obtain graphene loaded with silver seeds.

[0051] (2-1) Disperse the obtained graphene loaded with silver seeds in 10 mL of deionized water to prepare a dispersion of graphene loaded with silver seeds.

[0052] (2-2) Add 10mL of 120g L to the graphene dispersion loaded with silver seeds -1 silver nitrate solution, heated to 90°C, stirred for 1 hour,...

Embodiment 2

[0054] (1-1) Disperse 40mg graphene oxide in 100mL deionized water to make 0.4g L -1 Graphene oxide dispersion, add 80mL1.5g L -1 Silver nitrate solution, stirred, centrifuged.

[0055] (1-2) Disperse the obtained solid in 400mL of deionized water, and slowly add 120mL of 2g·L after heating up to 85°C -1 Sodium borohydride solution, keep the reaction temperature constant, continue to react for 4 hours, stop heating, filter after cooling to room temperature, wash the filter cake with distilled water and ethanol, and finally dry to obtain graphene loaded with silver seeds.

[0056] (2-1) The obtained graphene loaded with silver seeds was dispersed in 40 mL of deionized water to prepare a dispersion of graphene loaded with silver seeds.

[0057] (2-2) Add 10mL of 400g L to the graphene dispersion loaded with silver seeds -1 silver nitrate solution, heated to 85°C, stirred for 1 hour, then slowly added 70mL of 14g·L -1 The sodium borohydride solution, then continue to maintain...

Embodiment 3

[0059] (1-1) Disperse 30mg graphene oxide in 50mL deionized water to make 0.6g L -1 Graphene oxide dispersion, add 120mL0.5g L -1 Silver nitrate solution, stirred, centrifuged.

[0060] (1-2) Disperse the obtained solid in 90mL of deionized water, and slowly add 100mL of 3g·L after heating up to 80°C -1 Sodium borohydride solution, keep the reaction temperature constant, continue to react for 4 hours, stop heating, filter after cooling to room temperature, wash the filter cake with distilled water and ethanol, and finally dry to obtain silver-doped graphene oxide.

[0061] (2-1) The resulting graphene loaded with silver seeds was dispersed in 10 mL of deionized water to prepare a graphene dispersion loaded with silver seeds.

[0062] (2-2) Add 2.5mL of 300g L to the graphene dispersion loaded with silver seeds -1 silver nitrate solution, heated to 80°C, stirred for 1 hour, then slowly added 25mL of 10g·L -1 The sodium borohydride solution, then continue to maintain the tem...

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