The huge demand of HJT market is accelerating the industrialization of these technical requirements and existing problems. [silver Forum]

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At the 2021 China International Silver Industry chain Summit Forum and China Silver Market Application Symposium sponsored by (SMM) of SMM Information & Technology Co., Ltd., Hu Xiaobin, doctoral supervisor and associate professor of Shanghai Jiaotong University, introduced the mass production of HJT and the industrialization of wallet copper powder. He said that the industrialization of HJT is accelerated in 2021, the technical development and market development of domestic HJT cryogenic slurry is still in its infancy, and there are market opportunities for low-temperature slurry and silver-coated copper powder, and the market potential is huge. In addition, he also explained in detail the technical requirements of HJT low temperature slurry for silver-coated copper and the existing problems of silver-coated copper.

Heterojunction solar cell HJT based on N-type silicon wafer

At present, the mainstream application in the market is PERC+ monocrystalline silicon P-type solar cells, and its efficiency is close to the theoretical limit of 24.5%.

The theoretical limit of HJT/HIT--Heterojunction with Intrinsic Thin-Layer intrinsic heterojunction film is 27.5-29%.

It was first successfully developed by Sanyo Company of Japan in 1990, and domestic enterprises began to commercialize or plan heterojunction production lines in 2017. 2021 is the first year of heterojunction investment.

Accelerating industrialization of HJT in 2021

From the industrial point of view, according to incomplete statistics, the current heterojunction domestic planned production capacity over 60GW (1GW=1000MW), new and old battery manufacturers have layout.

Due to the significant improvement in the efficiency of heterojunction, there is a significant increase in the number of enterprises that begin to invest in the construction of HJT. 2020-2021 is the first year of heterojunction investment.

Because the technical route is very different from the high-temperature silver paste, the current suppliers of HJT low-temperature silver paste are also completely different.

At present, the largest market share supplier of HJT silver paste is KE, from Japan, which is currently developing silver-coated copper paste and copper paste to further reduce product costs.

Abroad, the American low-temperature silver paste giant Henkel is also one of the suppliers of HJT silver paste. Japan Nanotech, DuPont and Hercules have all developed HJT low-temperature silver paste products, but the current mass production is relatively small, and the technical characteristics of related products are unclear.

In China, the technical development and market development of HJT cryogenic slurry is still in its infancy. At present, it has been announced that there are 4-5 domestic manufacturers involved in this field, such as Changzhou Juhe, Shenzhen Shougou, Suzhou Jingyin, etc., but according to the technical feedback of HJT battery enterprises, there are not many manufacturers that have met the technical requirements of quantitative products. Suzhou Jingyin has developed low temperature silver coated copper paste.

There is a market opportunity for low-temperature slurry and silver-coated copper powder, and the market potential is huge.

Technical requirements of HJT low temperature slurry for Silver-coated Copper

In addition to meeting the conventional technical parameters of conductive silver paste, such as powder morphology, particle size distribution, vibrating density, specific surface area and so on, silver-coated copper powder has some special technical requirements as follows:

Silver to copper particles should be uniformly coated, fully covered and densely coated;

-the combination of silver and copper is firm and tight, and does not fall off at high speed.

-the silver coating has smooth surface and low oil absorption.

The silver coating has no penetrating pores, does not oxidize at high temperature, and is resistant to liquid acids and bases.

-the thickness of the silver coating is adjustable and the cost is controllable.

The current problems of silver-coated copper

The concept of copper cladding was put forward a long time ago, why is there no large-scale market application?

-the compactness of the coating is poor and it is not resistant to high temperature.

-the bonding of the coating is not strong and can not pass the three-roll machine;

-poor compactness, not resistant to gas and liquid penetration (not weather resistant);

-the surface is not smooth and the high oil absorption leads to low metal solid content.

At present, the pain points in the market include: high silver price, rigidity and great fluctuation; transparent cost of silver paste products; continuous reduction of silver powder processing fees and thin profits; and fierce market competition (price war, account period, acceptance, credit, kickbacks, etc.).

Huge market demand

Main market demand: photovoltaic silver / quilt silver, 5G, semiconductor packaging, electrical contact, low temperature touch screen, high thermal conductivity and high heat dissipation, silver-copper-carbon composites.

Photovoltaic battery cost control-price reduction drive

-structural change of photovoltaic grid line

-second largest cost

-reduction in kilowatt-hour cost

New photovoltaic technology route-efficiency drive

-HIT low temperature sintering

-perovskite low temperature sintering

-TOPcon

Price decline, expand the field of photovoltaic market, change the ecology of the industry

Technology is dynamic and can only be continuously improved through market testing. any new technology is not mature enough when it first enters the market. The market should give new technology opportunities, and enterprises should dare to try before they can courageously stand on the bandwagon.