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CN-121974565-A - Glass powder for BC battery fine grid line aluminum paste, preparation method thereof, aluminum paste and BC battery fine grid line

CN121974565ACN 121974565 ACN121974565 ACN 121974565ACN-121974565-A

Abstract

The disclosure provides glass powder for BC battery fine grid line aluminum paste, a preparation method thereof, aluminum paste and BC battery fine grid line, and belongs to the technical field of BC fine grid line paste. The glass powder comprises 2-3 parts by mass of conductive oxide, 2.5-3.5 parts by mass of rare earth oxide, 30-40 parts by mass of first component, 35-45 parts by mass of second component, 5-15 parts by mass of third component, and 5-15 parts by mass of third component, wherein the conductive oxide is at least one of MoO 3 、In 2 O 3 、SnO 2 , the rare earth oxide is at least one of La 2 O 3 、CeO 2 、Al 2 O 3 , the first component comprises at least one of Li 2 O、Na 2 O, caO, baO and SrO, the second component comprises at least one of V 2 O 5 、SiO 2 and B 2 O 3 , and the third component comprises at least one of PbO and Bi 2 O 3 , so that the corrosion and the suitability of the glass powder can be accurately regulated.

Inventors

  • MAO PING
  • JI JIANFEN
  • XU HAO
  • ZHANG XIAN
  • JIA XIAOYA

Assignees

  • 南通天盛新能源股份有限公司

Dates

Publication Date
20260505
Application Date
20260407

Claims (10)

  1. 1. A glass frit for BC battery fine grid line aluminum paste, the glass frit comprising: 2-3 parts by mass of a conductive oxide, which is at least one of MoO 3 、In 2 O 3 、SnO 2 ; 2.5 to 3.5 parts by mass of a rare earth oxide, wherein the rare earth oxide is at least one of La 2 O 3 、CeO 2 、Al 2 O 3 ; 30-40 parts by mass of a first component comprising at least one of Li 2 O、Na 2 O, caO, baO and SrO; 35-45 parts by mass of a second component comprising at least one of V 2 O 5 、SiO 2 and B 2 O 3 ; 5-15 parts by mass of a third component comprising at least one of PbO and Bi 2 O 3 .
  2. 2. The glass frit according to claim 1, wherein the conductive oxide is In 2 O 3 or SnO 2 .
  3. 3. The glass frit according to claim 1, wherein the rare earth oxide is La 2 O 3 or CeO 2 .
  4. 4. The glass frit according to claim 1, wherein the glass frit has a particle size of 1-5 μm and a particle size distribution span of 3 μm or less.
  5. 5. A method of preparing the glass frit according to any one of claims 1 to 4, comprising: uniformly mixing the conductive oxide, the rare earth oxide, the first component, the second component and the third component, and carrying out smelting treatment, quenching cooling and grinding treatment to obtain semi-finished glass powder with different particle sizes; And (3) carrying out jet milling and grading treatment to obtain the glass powder.
  6. 6. The method according to claim 5, wherein the semi-finished glass frit has a D50 of 25-45 μm; the particle size of the glass powder is 1-5 mu m, and the particle size distribution span is less than or equal to 3 mu m.
  7. 7. The method according to claim 5, wherein the smelting process is performed at a temperature of 1150-1250 ℃ for a time of 30-35 min.
  8. 8. An aluminum paste for BC battery fine grid lines, comprising: 75-85 parts by mass of aluminum powder; 1.5-4 parts by mass of a glass frit using the glass frit according to any one of claims 1-4; 15-21 parts by mass of an organic binder.
  9. 9. The aluminum paste as recited in claim 8, wherein the aluminum powder has a particle size of 2-8 μm, a purity of 99.7% or more, a surface oxide film thickness of 5nm or less, and a specific surface area of 1.0-2.5m 2 /g.
  10. 10. A BC battery string, characterized in that said BC battery string is formed by sintering the aluminum paste according to claim 8 or 9.

Description

Glass powder for BC battery fine grid line aluminum paste, preparation method thereof, aluminum paste and BC battery fine grid line Technical Field The disclosure belongs to the technical field of BC fine grid line slurry, and particularly relates to glass powder for BC battery fine grid line aluminum slurry, a preparation method of the glass powder, aluminum slurry and BC battery fine grid line. Background Aluminum paste replaces BC battery fine grid line silver paste, and is a trend of being driven together by the pressure reduction of the photovoltaic industry, technical iteration and material replacement requirements. The core action is that the silver paste cost is high, the gap for supplying and requiring silver is enlarged, the silver consumption of photovoltaic is more than 50% of global total demand, the silver paste consumption of the BC battery fine grid line is far more than that of a conventional PERC battery, the cost of the BC battery fine grid line is 40% of the non-silicon cost of the battery, the price of the aluminum paste is only 1/40-1/50 of that of the silver paste, and the cost reduction potential is remarkable. Meanwhile, the N-type battery is intensified in homogeneous competition, the industry falls into negative gross profit, and BC batteries need to be innovated through metallization technology. Other alternatives have limitations, copper paste needs to be matched with a silver seed layer and has insufficient industrialization suitability, and aluminum paste is applied in the photovoltaic field for more than 20 years, and has the advantages of mature home-made, fully verified reliability and obvious industrial matching advantage. In addition, "little silver/no silver" has been agreed in industry, and the head enterprise promotes aluminum paste formulation modification and process optimization, further provides technical support for substitution exploration. At present, related technologies for replacing BC fine grid line silver paste by a plurality of adaptation aluminum paste exist, the dimensions of paste formula improvement, process optimization and the like are covered, part of technologies are verified through experiments, and the technology floor exploration is further advanced by head enterprises, and the technology is specifically as follows: 1) The improved aluminum paste can reduce contact recombination loss by adjusting the components of the aluminum paste, such as developing Al-Si alloy aluminum paste containing 25-40% of silicon, inhibiting alloying reaction of aluminum and silicon and aluminum diffusion, or doping nitride to reduce work function, introducing SiC and the like to form a barrier layer, and the contact resistance of the improved aluminum paste is reduced to 0.4mΩ Cm 2, even better than silver contacts; 2) And a 257nm femtosecond ultraviolet laser is adopted to selectively remove the back SiN x layer, so that the contact opening is accurately controlled and the passivation structure is not damaged. Meanwhile, the sintering process is optimized, shallow etching pits can be formed like medium-speed sintering at 680 ℃, the passivation layer is prevented from being damaged, contact resistance and composite loss are balanced, and the efficiency gap between an aluminum paste TOPCon battery optimized by the process and a silver-based battery is reduced to 0.8%; 3) The aluminum paste replacement technology is combined with the OBB non-main gate technology, the problem of gate breaking is solved by improving the battery process and the assembly process, the assembly power is improved and mass production is realized by the scheme, the non-main gate is matched with the aluminum paste mode, the shading area can be further reduced, and the performance requirement of the BC battery is met. The aluminum paste is suitable for the N-type silicon of the BC battery, the contact problem is easy to occur, the work function difference between aluminum and N-type silicon is large, a Schottky barrier is easy to form at a contact interface, the contact resistance is high, aluminum and polysilicon can be mutually diffused to form a deeper eutectic layer, aluminum spike is easy to occur, passivation structures such as a battery tunneling oxide layer and the like are damaged, the problem is more serious along with the increase of the doping concentration of the polysilicon, and further the passivation effect is rapidly deteriorated. Disclosure of Invention The glass powder for the BC battery fine grid line aluminum paste, the preparation method, the aluminum paste and the BC battery fine grid line are provided. In one aspect of the disclosure, a glass frit for BC battery fine grid line aluminum paste is provided, the glass frit comprising: 2-3 parts by mass of a conductive oxide, which is at least one of MoO 3、In2O3、SnO2; 2.5 to 3.5 parts by mass of a rare earth oxide, wherein the rare earth oxide is at least one of La 2O3、CeO2、Al2O3; 30-40 parts by mass of a first component compri