CN115259675B - Glass powder for positive silver main grid slurry of N-type TOPCON crystalline silicon solar cell and preparation method thereof - Google Patents

Abstract

The invention discloses a glass powder for N-type TOPCON crystalline silicon solar cell positive silver main grid slurry and a preparation method thereof, which belongs to the technical field of solar photovoltaic cells. The glass powder includes the following components by weight: 10 to 60 %PbO/Pb ₂ O ₃ /Pb ₃ O ₄ , 0～10%TeO ₂ , 1～20%Bi ₂ O ₃ , 1～30%B ₂ O ₃ , 0.1～10%CaO, 0～3%CeO, 0~10% SiO ₂ , 0.1~15% (Li ₂ O+Na ₂ O+K ₂ O), 5~60% tensile agent, 1~10% sintering performance adjusting agent. The prepared glass powder is then added with 1%-5% silica and mixed thoroughly to obtain glass powder for positive silver main grid slurry. The obtained glass powder has high tensile strength after being sintered with the silicon wafer, and the produced slurry can be used at 750~850℃ Sintering can solve the problem of insufficient pulling force caused by the weight reduction of the front main grid paste of N-type TOPCON cells due to cost reduction requirements. In addition, the present invention has simple preparation steps and low cost, and is suitable for industrialized production.

Description

Glass powder for N-type TOPCON crystalline silicon solar cell positive silver main grid slurry and its preparation Preparation method

Technical field

The invention belongs to the technical field of solar photovoltaic cells, and specifically relates to a glass powder for positive silver main grid slurry of N-type TOPCON crystalline silicon solar cells and a preparation method thereof.

Background technique

Solar cell modules are one of the important products in the new energy industry. However, with the rapid development of new solar cell technologies such as new TOPCON and HJT, the positive silver paste of solar cells must undergo technical reforms, and glass powder, which is the key raw material of positive silver paste, must also keep pace with the times. It is urgent to match new battery technology. Since TOPCON technology performs double-sided passivation on the battery, that is, there is also silicon nitride and aluminum oxide film on the front side, the original glass powder has a low pulling force. In order to realize solar power generation as soon as possible and affordable, the slurry is reduced. The printing weight of the paste is an effective means to reduce the cost, but the reduction of the printing weight of the paste also leads to a further reduction of the pulling force. The present invention aims to solve the pulling force problem caused by the low weight.

Contents of the invention

In view of the above problems, the present invention provides a glass powder for positive silver main grid slurry of N-type TOPCON crystalline silicon solar cells, which solves the problem of low tensile force caused by the inability of traditional glass powder to adapt to the low grammage process.

In order to achieve the above objects, the technical solutions adopted by the present invention are:

A kind of glass powder for N-type TOPCON crystalline silicon solar cell positive silver main grid slurry. The glass powder body includes the following components by weight: 10 to 60% PbO/Pb ₂ O ₃ /Pb ₃ O ₄ , 0 to 10 %TeO ₂ , 1～20%Bi ₂ O ₃ , 1～30%B ₂ O ₃ , 0.1～10%CaO, 0～3%CeO, 0～10%SiO ₂ , 0.1～15% (Li ₂ O+ Na ₂ O + K ₂ O), 5 to 60% tensile additives, 1 to 10% sintering performance adjustment additives, the glass powder body and a certain proportion of white carbon black are fully mixed to obtain the positive silver main grid slurry. Glass powder.

It should be noted that: PbO/Pb ₂ O ₃ /Pb ₃ O ₄ means any one of PbO, Pb ₂ O ₃ and Pb ₃ O _4. In this application, PbO/Pb ₂ O ₃ /Pb ₃ O ₄ is added Mainly to increase the pulling force of the main grid slurry. Li ₂ O+Na ₂ O+K ₂ O represents a combination of three oxides, which can be one or several oxides.

As a further technical solution, the tensile aid is one or a mixture of two or more of V ₂ O ₅ , Sb ₂ O ₃ , NaF, LiF, PbF ₂ , AlF ₃ and TiF ₄ in any proportion. The main function of the tensile additive is to adjust the surface tension of the glass, improve the wettability of the glass, and increase the tensile force.

As a further technical solution, the sintering performance adjustment aid is one or a mixture of two or more of TiO ₂ , MnO ₂ , WO ₃ , Ge ₂ O ₃ , Fe ₂ O ₃ , ZnO, and NiO in any proportion. The main function of the sintering performance adjustment additive is to adjust the glass sintering temperature, improve the chemical stability of the glass, and improve the tensile strength.

As a further technical solution, the Tg temperature of the glass powder is 320°C to 440°C, and the Ts temperature of the glass powder is 480°C to 580°C.

As a further technical solution, the glass powder requires mixing the melted and refined glass powder body with 1%-5% white carbon black to obtain glass powder for positive silver main grid slurry. The purpose of adding white carbon black is For improved shaping, less current loss.

Furthermore, the average particle size of the glass powder is 0.3 to 3 microns, and the particle size requirements will be adjusted according to different application conditions of the slurry.

The invention also proposes a method for preparing glass powder for the above-mentioned N-type TOPCON crystalline silicon solar cell positive silver main grid slurry, which includes the following steps:

(1) After weighing each component of the glass powder body according to mass percentage, put it into a mixer and mix;

(2) Put the uniformly mixed glass powder raw materials into the platinum crucible, and then put them into the pre-burning equipment for pre-sintering;

(3) Put the pre-fired crucible into a high-temperature furnace, and after high-temperature smelting and heat preservation for a period of time, a clear glass melt is obtained;

(4) Pour the glass melt into the double-roller machine for cold rolling, and collect the cold-rolled glass fragments;

(5) Refine the glass fragments to an average particle size of 0.3 to 3 microns;

(6) Mix the refined glass powder body with white carbon black to obtain glass powder for positive silver main grid slurry.

Preferably, the stirring and mixing time in step (1) is 10 to 30 minutes; the pre-calcining temperature in step (2) is 300-400°C, and the pre-calcining time is 0.5-1 hour; and the high-temperature melting temperature in step (3) is 900°C. ~1200℃, holding time is 1~2 hours.

Preferably, in step (5), a ball mill is used for wet grinding or a jet pulverizer to refine the glass fragments, and in step (6), the stirring and mixing time is 5 to 10 minutes.

beneficial effects

Through the technical solution of the present invention, the low-grammage printing process of TOPCON batteries can be adapted. The slurry made of the prepared glass powder can be sintered at 750-850°C. The Pb-Bi-B system glass powder used in the present invention has a low softening temperature and is good for silicon. The sheet and silver powder have good wettability and good density after sintering, thereby increasing the front welding tension of the cell. The addition of white carbon black increases the aspect ratio of the printed line and reduces current loss. At the same time, the nano-scale particle size of white carbon black is much smaller than that of silver powder. The particle size can also improve the density of the slurry after sintering to a certain extent, thereby increasing the tensile strength, which solves the problem of unqualified tensile strength after reducing the printing weight of the slurry. In addition, the present invention has simple preparation steps and low cost, and is suitable for industrialized production.

Detailed ways

The technical solutions in the embodiments of the present invention are clearly and completely described below. It is obvious that the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

Example 1

The composition and weight percentage of the glass powder in this embodiment: 52% PbO, 10% TeO ₂ , 13% Bi ₂ O ₃ , 10% B ₂ O ₃ , 2% CaO, 1% CeO, 2% SiO ₂ , 0.5% Li ₂ O, 5% V ₂ O ₅ , 1% TiF ₄ , 3% MnO ₂ , 0.5% Ge ₂ O ₃ are mixed in a stirrer for 10 minutes. After mixing evenly, put them into a platinum crucible. Put the crucible into the pre-sintering equipment, raise the temperature of the pre-sintering equipment to 350°C and pre-sinter for 1 hour. Quickly put the pre-sintered crucible into a high-temperature furnace for smelting at 1000° C. and keep it warm for 1 hour to obtain a clear glass melt. Put the glass melt into the double roller machine for cold rolling. After cooling, take out the glass fragments. Use a ball mill to wet-grind the glass fragments to an average particle size of 1.5 microns. Add the obtained glass powder and 1% white carbon black and mix it in a stirrer for 5 minutes. Prepare the required glass powder;

Weigh according to the following formula proportion: 85% silver powder, 1% glass powder, 13.5% organic carrier, 0.5% dispersant, weigh and add to the sample tank for manual pre-stirring, then mix evenly in a planetary mixer or other mixer, and then After being dispersed to less than 10 μm on a three-roller machine and filtered through a 400-mesh screen, a very uniform silver paste for the front main grid of the solar cell can be obtained. The viscosity of the slurry is 160 Pa.s (25°C). The number of N-type TOPCON cells tested is 500. Randomly select three pieces each to test the tensile strength and the aging tensile strength to take the average value and compare the production line (commercially available products) The results are shown in Table 1.

Example 2

The composition and weight percentage of the glass powder in this embodiment: 48% Pb ₂ O ₃ , 8% TeO ₂ , 18% Bi ₂ O ₃ , 10% B ₂ O ₃ , 2% CaO, 1% CeO, 2% SiO ₂ , 1% Li ₂ O, 5% V ₂ O ₅ , 1% TiF ₄ , 3% MnO ₂ , 1% Ge ₂ O ₃ , mix in a stirrer for 10 minutes, mix evenly and put into a platinum crucible. Put the crucible into the pre-sintering equipment, raise the temperature of the pre-sintering equipment to 350°C and pre-sinter for 1 hour. Quickly put the pre-sintered crucible into a high-temperature furnace for smelting at 1000° C. and keep it warm for 1 hour to obtain a clear glass melt. Put the glass melt into the double roller machine for cold rolling. After cooling, take out the glass fragments. Use a ball mill to wet-grind the glass fragments to an average particle size of 1.5 microns. Add the obtained glass powder to a mixer with 3% silica and mix for 5 minutes. Prepare the required glass powder;

Weigh according to the following formula proportion: 85% silver powder, 1% glass powder, 13.5% organic carrier, 0.5% dispersant, weigh well, add it to the sample tank and pre-stir manually, then mix evenly in a planetary mixer or other mixer, and then After being dispersed to less than 10 μm on a three-roller machine and filtered through a 400-mesh screen, a very uniform silver paste for the front main grid of the solar cell can be obtained. The viscosity of the slurry is 150 Pa.s (25°C), and the number of N-type TOPCON cells tested is 500. Randomly select three pieces each to test the tensile strength and the aging tensile strength, and take the average value to compare the production line (commercially available products) The results are shown in Table 1.

Example 3

The composition and weight percentage of the glass powder in this embodiment: 44%Pb ₃ O ₄ , 6% TeO ₂ , 15% Bi ₂ O ₃ , 20% B ₂ O ₃ , 2% CaO, 1% CeO, 2% SiO ₂ , 0.5% Li ₂ O, 5% V ₂ O ₅ , 1% TiF ₄ , 3% MnO ₂ , 0.5% Ge ₂ O ₃ , mix in a stirrer for 10 minutes, mix evenly and put into a platinum crucible. Put the crucible into the pre-sintering equipment, raise the temperature of the pre-sintering equipment to 350°C and pre-sinter for 1 hour. Quickly put the pre-sintered crucible into a high-temperature furnace for smelting at 1000° C. and keep it warm for 1 hour to obtain a clear glass melt. Put the glass melt into the double roller machine for cold rolling. After cooling, take out the glass fragments. Use a ball mill to wet-grind the glass fragments to an average particle size of 1.5 microns. Add the obtained glass powder to a mixer with 4% silica and mix for 5 minutes. Prepare the required glass powder;

Weigh according to the following formula proportion: 85% silver powder, 1% glass powder, 13.5% organic carrier, 0.5% dispersant, weigh well, add it to the sample tank and pre-stir manually, then mix evenly in a planetary mixer or other mixer, and then After being dispersed to less than 10 μm on a three-roller machine and filtered through a 400-mesh screen, a very uniform silver paste for the front main grid of the solar cell can be obtained. The viscosity of the slurry is 155 Pa.s (25°C). The number of N-type TOPCON cells tested is 500. Randomly select three pieces each to test the tensile strength and the aging tensile strength to take the average value and compare the production line (commercially available products) The results are shown in Table 1.

(It should be noted that the organic carriers mentioned in Examples 1-3 are commonly used organic carriers in the field of conductive silver paste for solar cells and belong to the existing technology and will not be described in detail here. The dispersant uses TDO)

Table 1 Tensile performance of solar cells in various embodiments and comparative production lines

Tensile force/N Aging tensile strength/N Production line 2.48 1.99 Example 1 2.81 2.42 Example 2 3.02 2.60 Example 3 3.11 2.94

It can be seen from the cell sheet tensile test results that the slurry prepared by the glass powder of this system has high tensile strength and aging tensile strength, indicating that it effectively solves the problem of unqualified tensile strength under low grammage of slurry printing. In summary, the glass powder in the present invention is adapted to the low-gram weight printing process of TOPCON battery cells and effectively improves the battery front pulling force.

The above description is only illustrative of the present invention and not restrictive. Those of ordinary skill in the art will understand that many modifications, changes, etc. can be made without departing from the spirit and scope defined by the appended claims. effect, but all will fall within the protection scope of the present invention.

Claims (7)

1. The glass powder for the positive silver main grid slurry of the N-type TOPCON crystalline silicon solar cell is characterized in that the glass powder body comprises the following components in percentage by weight: 44-60% PbO/Pb ₂ O ₃ /Pb ₃ O ₄ ，0～10%TeO ₂ 、13～20％Bi ₂ O ₃ 、10～30%B ₂ O ₃ 、0.1～10%CaO、0～3%CeO ₂ 、0～10%SiO ₂ 、0～10%Al ₂ O ₃ 、0.1～15% (Li ₂ O+Na ₂ O+K ₂ O), 5-60% of a tension aid and 1-10% of a sintering property adjusting aid, wherein the glass powder body is fully mixed with 1% -5% of white carbon black to obtain glass powder for positive silver main grid slurry;

the tension aid is V ₂ O ₅ 、Sb ₂ O ₃ 、NaF、LiF、PbF _2、 AlF ₃ 、TiF ₄ One or more than two of the components in any proportion;

the sintering property regulating auxiliary agent is TiO ₂ 、MnO ₂ 、WO ₃ 、Ge ₂ O ₃ 、Fe ₂ O ₃ One or more than two of ZnO and NiO in any proportion.

2. The glass powder for the positive silver main grid paste of the N-type TOPCON crystalline silicon solar cell, which is disclosed in claim 1, is characterized in that the glass powder has a Tg temperature of 320-440 ℃ and a glass powder Ts temperature of 480-580 ℃.

3. The glass powder for the positive silver main grid paste of the N-type TOPCO crystalline silicon solar cell, which is disclosed in claim 1, is characterized in that the average particle size of the glass powder is 0.3-3 microns.

4. A method for preparing glass powder for positive silver primary grid paste of N-type TOPCON crystalline silicon solar cell according to any one of claims 1-3, comprising the following steps:

(1) Weighing the components of the glass powder body according to the mass percentage, and then putting the glass powder body into a stirrer for mixing and stirring;

(2) Placing the uniformly mixed glass powder body raw materials into a platinum crucible, and then placing into presintering equipment for presintering;

(3) Placing the presintered crucible into a high-temperature furnace, and carrying out high-temperature smelting and heat preservation for a period of time to obtain a clarified glass melt;

(4) Pouring the glass melt into a pair roller machine for cold rolling, and collecting the cold-rolled glass fragments;

(5) Refining the glass fragments to an average particle size of 0.3-3 microns;

(6) And stirring and mixing the refined glass powder with white carbon black to obtain the glass powder for the positive silver main grid slurry.

5. The preparation method of the glass powder for the positive silver main grid paste of the N-type TOPCON crystalline silicon solar cell, which is disclosed in claim 4, is characterized in that the stirring and mixing time in the step (1) is 10-30 minutes; in the step (2), the presintering temperature is 300-400 ℃ and the presintering time is 0.5-1 hour.

6. The preparation method of the glass powder for the positive silver main grid paste of the N-type TOPCON crystalline silicon solar cell, which is disclosed in claim 4, is characterized in that the high-temperature smelting temperature in the step (3) is 900-1200 ℃, and the heat preservation time is 1-2 hours.

7. The preparation method of the glass powder for the positive silver main grid slurry of the N-type TOPCON crystalline silicon solar cell, which is disclosed in claim 4, is characterized in that in the step (5), a ball mill wet grinding or a jet mill is adopted to refine glass fragments; in the step (6), stirring and mixing time is 5-10 minutes.