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CN-121983370-A - Conductive paste, preparation method of conductive paste, solar cell, preparation method of solar cell and photovoltaic module

CN121983370ACN 121983370 ACN121983370 ACN 121983370ACN-121983370-A

Abstract

The application relates to a conductive paste, a preparation method thereof, a solar cell, a preparation method thereof and a photovoltaic module. The conductive paste comprises 82% -88% of metal powder, 1% -5% of glass powder, 8% -15% of organic carrier, 0.5% -3% of wave-absorbing material and 0.1% -1% of polymer pore-forming agent, wherein the wave-absorbing material can absorb laser and release heat. During the laser-assisted sintering treatment, the wave-absorbing material can efficiently absorb laser energy and instantaneously release heat, so that the surrounding polymer pore-forming agent is rapidly gasified. The polymer pore-forming agent is gasified to form a cavity structure in the conductive slurry, so that a multiple reflection cavity of light is formed, laser subsequently transmitted in the cavity is reflected for multiple times, a light path is prolonged, and the absorptivity of laser energy is greatly improved. The high absorptivity of the laser allows for a laser power required to form a good ohmic contact, reduces energy consumption, and reduces damage to the cell surface.

Inventors

  • LI ZHONGCHENG
  • ZHOU HUAMING
  • LI FEIYUN
  • ZHU LIANGLIANG
  • ZHANG LEI

Assignees

  • 晶科能源(海宁)有限公司

Dates

Publication Date
20260505
Application Date
20260210

Claims (15)

  1. 1. The conductive paste is characterized by comprising metal powder, glass powder, an organic carrier, a wave absorbing material and a polymer pore-forming agent, wherein the wave absorbing material can absorb laser and release heat, the mass fraction of the metal powder is 82% -88%, the mass fraction of the glass powder is 1% -5%, the mass fraction of the organic carrier is 8% -15%, the mass fraction of the wave absorbing material is 0.5% -3%, and the mass fraction of the polymer pore-forming agent is 0.1% -1%.
  2. 2. The conductive paste according to claim 1, wherein the polymer pore-forming agent has a granular structure with a D50 particle size of 1 μm to 5 μm.
  3. 3. The conductive paste according to claim 1, wherein the thermal decomposition temperature of the polymer pore-forming agent is 200 ℃ to 500 ℃.
  4. 4. The conductive paste of claim 1, wherein the polymeric pore former material comprises one or more of polymethyl methacrylate, polystyrene, polylactic acid, polyvinyl butyral, and expanded microspheres comprising a thermoplastic polymer shell and a volatile alkane disposed in the thermoplastic polymer shell.
  5. 5. The conductive paste of claim 1, wherein the wave-absorbing material comprises one or more of tellurium, antimony, and tungsten trioxide.
  6. 6. The conductive paste according to claim 1, wherein the wave-absorbing material has a granular structure with a D50 particle size of 1 μm to 5 μm, and a coating layer is provided on the surface of the wave-absorbing material, and the material of the coating layer includes one or more of a surfactant, a silane coupling agent, a polymer dispersing agent, and an organic acid.
  7. 7. The conductive paste of claim 6, wherein the surfactant comprises one or more of sodium dodecyl benzene sulfonate, sodium dodecyl sulfonate, alkylphenol ethoxylate phosphate, cetyltrimethylammonium bromide, fatty alcohol polyoxyethylene ether, and alkylphenol polyoxyethylene ether; And/or the silane coupling agent comprises one or more of aminopropylalkoxysilane, glycidol ether oxypropylalkoxysilane, mercaptopropylalkoxysilane, vinylalkoxysilane and methacryloxypropylalkoxysilane; And/or the polymeric dispersant comprises one or more of polyvinylpyrrolidone and polyvinyl alcohol; and/or the organic acid comprises one or more of oleic acid, stearic acid, palmitic acid and linoleic acid.
  8. 8. The conductive paste of any one of claims 1 to 7, wherein the metal powder comprises one or more of silver powder, aluminum powder, copper powder, nickel powder, silver-coated copper powder, and silver-coated nickel powder.
  9. 9. A method for preparing the conductive paste according to any one of claims 1 to 8, comprising the steps of: Stirring and mixing the organic carrier and the glass powder to obtain a first mixture; rolling and mixing the first mixture and the metal powder to obtain a second mixture; Rolling and mixing the second mixture and the wave-absorbing material to obtain a third mixture; and rolling and mixing the third mixture and the polymer pore-forming agent to obtain a fourth mixture.
  10. 10. A method of manufacturing a solar cell, comprising the steps of: Providing a battery body; Coating a conductive paste on the battery body, wherein the conductive paste is the conductive paste according to any one of claims 1-8 or the conductive paste prepared by the preparation method according to claim 9; and performing laser-assisted sintering treatment on the conductive slurry to form a first sintered product.
  11. 11. The method for manufacturing a solar cell according to claim 10, wherein the laser used for the laser-assisted sintering treatment has a wavelength of 1000nm to 1300nm and a power of 170w to 230w.
  12. 12. The method of manufacturing a solar cell according to claim 10 or 11, further comprising the steps of: and carrying out heating sintering treatment on the first sintering product to form a second sintering product.
  13. 13. The method of manufacturing a solar cell according to claim 12, wherein the temperature of the heat sintering treatment is 500 ℃ to 600 ℃.
  14. 14. A solar cell, characterized in that it is produced by the production method according to any one of claims 10 to 13.
  15. 15. A photovoltaic module comprising a first encapsulant component, a second encapsulant component, and the solar cell of claim 14 disposed between the first encapsulant component and the second encapsulant component.

Description

Conductive paste, preparation method of conductive paste, solar cell, preparation method of solar cell and photovoltaic module Technical Field The application relates to the technical field of photovoltaics, in particular to conductive paste, a preparation method of conductive paste, a solar cell, a preparation method of solar cell and a photovoltaic module. Background The grid lines on the solar cell can be formed by sintering after being coated by conductive paste (such as silver paste). The sintering process includes a heat sintering process, a laser assisted sintering (LECO) process, and the like. The core principle of the laser-assisted sintering process is that laser-induced local carrier injection and instantaneous high-temperature synergism are achieved, metal-silicon contact is optimized, and therefore battery efficiency is improved. However, the laser-assisted sintering process has a problem in that the conductive paste has a low absorptivity of laser energy. The metal particles (such as silver particles) in the conventional conductive paste have limited absorptivity to the common infrared laser (wavelength of 1064nm, for example), and a large amount of laser energy is reflected or transmitted, resulting in energy waste. To meet the process requirements, a higher laser power is required, which not only increases the energy consumption, but also easily damages the surface of the battery, such as the passivation layer of the surface, due to the excessively high local energy, resulting in a drop in open circuit voltage (Voc). Disclosure of Invention Based on the above, it is necessary to provide a conductive paste and a preparation method thereof, a solar cell and a preparation method thereof, and a photovoltaic module, so as to solve the problem of low laser energy absorption rate of the conventional conductive paste stack. The first aspect of the application provides a conductive paste, which comprises the following steps: The conductive paste comprises metal powder, glass powder, an organic carrier, a wave absorbing material and a polymer pore-forming agent, wherein the wave absorbing material can absorb laser and release heat, the mass fraction of the metal powder is 82% -88%, the mass fraction of the glass powder is 1% -5%, the mass fraction of the organic carrier is 8% -15%, the mass fraction of the wave absorbing material is 0.5% -3%, and the mass fraction of the polymer pore-forming agent is 0.1% -1%. In some embodiments, the polymeric pore former is a granular structure with a D50 particle size of 1-5 μm. In some embodiments, the thermal decomposition temperature of the polymeric pore former is 200 ℃ to 500 ℃. In some of these embodiments, the polymeric pore former material comprises one or more of polymethyl methacrylate, polystyrene, polylactic acid, polyvinyl butyral, and expanded microspheres comprising a thermoplastic polymer shell and a volatile alkane disposed in the thermoplastic polymer shell. In some of these embodiments, the wave absorbing material includes one or more of tellurium, antimony, and tungsten trioxide. In some embodiments, the wave-absorbing material has a granular structure with a D50 particle size of 1-5 μm, and a coating layer is arranged on the surface of the wave-absorbing material, wherein the material of the coating layer comprises one or more of a surfactant, a silane coupling agent, a polymer dispersing agent and an organic acid. In some embodiments, the surfactant comprises one or more of sodium dodecyl benzene sulfonate, sodium dodecyl sulfonate, alkylphenol ethoxylate phosphate, cetyltrimethylammonium bromide, fatty alcohol polyoxyethylene ether, and alkylphenol polyoxyethylene ether. In some of these embodiments, the silane coupling agent includes one or more of aminopropylalkoxysilane, glycidoxypropylalkoxysilane, mercaptopropylalkoxysilane, vinylalkoxysilane, methacryloxypropylalkoxysilane. In some of these embodiments, the polymeric dispersant comprises one or more of polyvinylpyrrolidone and polyvinyl alcohol. In some of these embodiments, the organic acid comprises one or more of oleic acid, stearic acid, palmitic acid, and linoleic acid. In some of these embodiments, the metal powder comprises one or more of silver powder, aluminum powder, copper powder, nickel powder, silver-coated copper powder, and silver-coated nickel powder. The second aspect of the present application provides a method for preparing the above-mentioned conductive paste, which comprises the following steps: A preparation method of conductive paste comprises the following steps: Stirring and mixing the organic carrier and the glass powder to obtain a first mixture; rolling and mixing the first mixture and the metal powder to obtain a second mixture; Rolling and mixing the second mixture and the wave-absorbing material to obtain a third mixture; and rolling and mixing the third mixture and the polymer pore-forming agent to obtain a fourth mixture. The third aspect of the applicat