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CN-116621459-B - Glass powder with weak corrosion and high conductivity and application thereof

CN116621459BCN 116621459 BCN116621459 BCN 116621459BCN-116621459-B

Abstract

The application provides a glass powder with weak corrosion and high conductivity, which comprises, by weight, 30-50% of SiO 2 , 0.5-2% of Al 2 O 3 , 0.5-25% of CdO, 0.5-10% of MnO 2 , 0.5-6% of ZnO, 3-23% of CuO, 5-30% of Bi 2 O 3 , 0-5% of TeO 2 , 1-13% of rare earth metal oxide, and 1-35% of MoO 3 and/or WO 3 , wherein the glass powder shows lower activity and corrosiveness to a passivation layer in PERC battery by utilizing the synergistic effect of the components, and when the glass powder is used in PERC solar battery back silver paste, the silver paste shows excellent adhesion and conductivity, and improves the conversion efficiency, stability and aging resistance of the battery.

Inventors

  • HUANG LIANGHUI
  • HUANG YUEJIAN
  • HUANG HAO
  • LIANG YINGYING

Assignees

  • 广东南海启明光大科技有限公司
  • 佛山市瑞纳新材科技有限公司

Dates

Publication Date
20260512
Application Date
20230523

Claims (8)

  1. 1. The glass powder with weak corrosion and high conductivity is characterized in that the glass powder comprises, by total weight, 30-50% of SiO2, 0.5-2% of Al 2 O 3 , 4-20% of CdO, 0.5-10% of MnO 2 , 0.5-6% of ZnO, 5-18% of CuO, 5-30% of Bi 2 O 3 , 0-5% of TeO 2 and 1-13% of metal oxide; The metal oxides are Y 2 O 3 and Nb 2 O 5 ; The weight percentage of the Y 2 O 3 in the glass powder is 0.5-5%; The weight percentage of Nb 2 O 5 in the glass powder is 1-8%.
  2. 2. The glass frit according to claim 1, wherein the raw materials of the glass frit further comprise 1-35% MoO 3 and/or WO 3 .
  3. 3. The glass frit according to claim 2, wherein the weight percentage of MoO3 in the glass frit is 1-5% and the weight percentage of WO 3 in the glass frit is 4-30%.
  4. 4. The glass frit according to claim 3, wherein the glass frit has a D 50 average particle size of 0.5-7 μm, a glass transition temperature of 550-700 ℃ and a coefficient of thermal expansion of (1-5) x 10 -6 /°.
  5. 5. Use of the glass frit with weak corrosion and high conductivity according to any one of claims 1 to 4 in PERC solar cell backside silver paste.
  6. 6. The use according to claim 5, wherein the back side silver paste comprises, by weight, 50-64% silver powder, 0.5-2% glass frit, and the balance of organic phase to 100%.
  7. 7. The use according to claim 6, wherein the silver powder has a D 50 average particle size of 0.5-5 μm, tap density of 3-8g/mL, and specific surface area of 0.2-0.9cm 2 /g.
  8. 8. The use according to claim 7, characterized in that the dry layer thickness of the silver paste on the back side of the PERC solar cell is 10-20 μm.

Description

Glass powder with weak corrosion and high conductivity and application thereof Technical Field The invention relates to the technical field of crystalline silicon solar cells, in particular to glass powder with weak corrosion and high conductivity and application thereof. Background PERC cells are one of the solar cell technologies that improves conversion efficiency by adding a dielectric passivation layer on the back side of the cell that maximizes the potential gradient across the P-N junction in standard cell structures, allowing electrons to flow more stably, reducing recombination, and improving conversion efficiency. Silver paste materials are printed on the front side and the back side of a silicon substrate in the manufacturing process of the crystalline silicon solar cell, the front side silver paste mainly plays a role in collecting and leading out photo-generated carriers, the back side silver paste mainly plays a role in adhesion, the cell sheets are connected in series or in parallel, the requirement on the conductivity is relatively low, but the corrosiveness of the back side silver paste on a passivation layer on the back side of the PERC cell or the too low conductivity has a great influence on the efficiency of the cell sheets, and the key performance of the back side silver paste is determined by the glass powder performance. Most of the back silver paste products on the market still have the following problems that (1) the glass powder has too high activity, the open circuit voltage is lower due to deeper corrosion on a silicon wafer, and the conductivity of the silver paste cannot be considered when the glass powder activity is reduced, so that the series resistance is higher, and finally, the reaction is reduced in the filling factor and the efficiency, and (2) after the silicon battery piece is sintered, the interface between the back aluminum paste and the silver paste is cracked, so that the contact resistance is increased, the battery efficiency is reduced, the welding performance and the adhesive force of a back electrode are reduced, and the like, so that the optimal design is carried out on the glass powder formula system and the components for the silver paste on the back of the PERC battery, and the aim of improving the efficiency is fulfilled. Chinese patent CN103771715B discloses glass powder for silver paste on the back of a solar cell and a preparation method thereof, wherein the glass powder A40-99, the glass powder B0-60 and the inorganic additive 0-10 of different components are proportioned in the technology to reduce the consumption of glass powder and silver powder and improve the electrode sintering window, but the glass powder comprises lead oxide with adverse effects on human bodies and environment, and does not accord with the development trend of future technologies and policies. Chinese patent CN103193391B discloses a lead-free glass powder for silver paste on the back of crystalline silicon solar cell and a preparation method thereof, in the technology, the adhesive force between the paste and the silicon substrate is enhanced by optimizing the component proportion to match the expansion coefficient of the glass powder and the silicon wafer, but the content of silicon dioxide in the glass powder is still less, the structural stability of the glass powder cannot be ensured, and the welding resistance and the like still need to be improved. Therefore, glass powder with weak corrosiveness, high conductivity, stable structure, good silver paste adhesion performance, excellent welding resistance, aging resistance and the like needs to be developed to match the application of the glass powder in PERC solar cells. Disclosure of Invention In order to solve the technical problems, the invention firstly provides a glass powder with weak corrosion and high conductivity, which comprises, by weight, 30-50% of SiO 2, 0.5-2% of Al 2O3, 0.5-25% of CdO, 0.5-10% of MnO 2, 0.5-6% of ZnO, 3-23% of CuO, 5-30% of Bi 2O3, 0-5% of TeO 2 and 1-13% of rare earth metal oxide. The glass powder composition and the weight ratio are optimized, so that the corrosion, the conductivity, the aging tension and other key performances of the silver paste on the back surface of the glass powder are balanced better; in the glass powder, si-O tetrahedron of SiO 2 provides the whole framework of glass, al 2O3 improves the structural stability of a glass system, improves the acid resistance of the glass and effectively reduces the expansion coefficient, but the reinforcing effect is insufficient, so that the added Bi 2O3 mixes the network structure of the Bi-O tetrahedron in the whole structure of the glass, increases the structural stability and widens the temperature window of the glass, znO has fluxing action, increases the high-temperature fluidity of the glass, further reduces the thermal expansion coefficient, but when the adding amount is excessive, the glass is easy to crystallize in the quench