Contact-enhanced N-type battery front silver paste and preparation method thereof

Abstract

The invention discloses a contact-enhanced N-type cell front silver paste and a preparation method thereof, and relates to the technical field of solar cell silver pastes.The silver paste is composed of, by weight, 0.01-10 parts of an inorganic auxiliary agent for enhancing contact; 55-100 parts by weight of micron-scale or nano-scale spherical silver powder; 0.1 to 20 parts by weight of glass powder; 1-25 parts by weight of an organic carrier; 0.1 to 10 parts by weight of aluminum powder; and 0.05-8 parts by weight of an organic auxiliary agent. In the invention, when the silver paste is prepared, an inorganic auxiliary agent, micron-scale or nano-scale spherical silver powder, glass powder, an organic carrier and aluminum powder are poured into a stirrer and are uniformly mixed with an organic auxiliary agent to obtain the front silver paste for the N-type battery, the inorganic auxiliary agent for enhancing contact comprises FeF3 and / or K2SO3 and / or TiC and / or Mg2Si and / or MoO3 and / or graphene, and the inorganic auxiliary agent for enhancing contact comprises FeF3 and / or K2SO3 and / or TiC and / or Mg2Si and / or MoO3 and / or graphene. The inorganic auxiliary agents destroy an aluminum oxide layer wrapping the aluminum powder, so that the aluminum powder can fully participate in the sintering process, the contact performance of the battery piece is improved, the filling factor is improved, and the higher conversion efficiency is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cell silver paste, in particular to a contact-enhanced N-type cell front silver paste and a preparation method thereof. Background Art

[0002] Amidst the global energy transition towards renewable energy, solar energy, as an inexhaustible clean energy source, is booming at an unprecedented rate, carrying humanity's ardent expectations for a sustainable future. As the core technology in this field, every leap in the performance of solar cells is like a shot in the arm for energy transformation, pushing the entire industry to new heights.

[0003] In recent years, N-type solar cells have emerged as a rapidly emerging force, demonstrating tremendous potential to surpass traditional P-type cells due to their unique physical properties. N-type cells boast higher carrier mobility, meaning electrons can move more smoothly through them, significantly reducing resistive losses. Furthermore, their lower intrinsic recombination rate effectively reduces the probability of electron-hole recombination, laying a solid foundation for achieving higher photoelectric conversion efficiency. These significant performance advantages have rapidly made them a cutting-edge field of research, attracting significant financial and technological investment and becoming a key force in driving the upgrading of the solar industry. In the manufacturing process of N-type cells, the selection and performance optimization of front-side electrode materials are crucial. Silver-aluminum paste, a commonly used front-side electrode material, plays a key role in reducing costs and improving cell performance due to its unique advantages. The clever introduction of aluminum not only effectively reduces the use of expensive silver, bringing significant cost advantages for large-scale production, but also forms an extremely good ohmic contact with the boron-doped region on the front side of the N-type cell, creating a high-speed channel for current transmission, significantly improving the cell's open-circuit voltage and fill factor, thereby significantly enhancing the cell's conversion efficiency.

[0004] Aluminum, as an extremely active element, is easily naturally oxidized in the air, forming a dense aluminum oxide film on the outside. The melting temperature of aluminum oxide is as high as over 2000°C, which isolates the reaction between aluminum and silver, resulting in the inability to smoothly form silver-aluminum-silicon alloy and the inability to achieve the expected fill factor effect. At the same time, due to the instability of air oxidation, the same amount of aluminum powder added cannot guarantee the consistency of the effective aluminum component involved in the sintering process each time. Therefore, there is an urgent need for an N-type battery front silver paste with enhanced contact and its preparation method. Summary of the Invention

[0005] The purpose of the present invention is to provide an N-type battery front silver paste with enhanced contact and a preparation method thereof in order to solve the problem that the aluminum powder in the N-type silver-aluminum paste is isolated from the outside by the aluminum oxide film due to the existence of the oxidation reaction and cannot participate in the reaction as expected, which manifests as poor contact performance and low fill factor parameters in the electrical performance.

[0006] To achieve the above objectives, the present invention provides the following technical solutions: a silver paste for an N-type battery with enhanced contact and a preparation method thereof, wherein the silver paste comprises the following components:

[0007] 0.01-10 parts by weight of an inorganic additive for enhancing contact;

[0008] 55-100 parts by weight of micron- or nano-sized spherical silver powder;

[0009] 0.1-20 parts by weight of glass powder;

[0010] 1-25 parts by weight of an organic carrier;

[0011] 0.1-10 parts by weight of aluminum powder;

[0012] 0.05-8 parts by weight of organic additives.

[0013] Preferably, the silver paste consists of the following components:

[0014] 0.02-5 parts by weight of an inorganic additive for enhancing contact;

[0015] 75-95 parts by weight of micron- or nano-sized spherical silver powder;

[0016] 0.5-10 parts by weight of glass powder;

[0017] 3-20 parts by weight of an organic carrier;

[0018] 0.3-5 parts by weight of aluminum powder;

[0019] 0.1-5 parts by weight of organic additives.

[0020] Preferably, the silver paste consists of the following components:

[0021] 0.5-2 parts by weight of an inorganic additive for enhancing contact;

[0022] 80-90 parts by weight of micron- or nano-sized spherical silver powder;

[0023] 1-6 parts by weight of glass powder;

[0024] 5-15 parts by weight of an organic carrier;

[0025] 0.5-3 parts by weight of aluminum powder;

[0026] 0.2-3 parts by weight of organic additives.

[0027] Preferably, the contact-enhancing inorganic additive is FeF3 and / or K2SO3 and / or TiC and / or Mg2Si and / or MoO3 and / or graphene.

[0028] Preferably, the glass powder is composed of the following raw materials: 2-35% boron oxide, 0-6% aluminum oxide, 0-70% lead oxide, 2-30% zinc oxide, 5-50% barium oxide, 0-30% vanadium oxide, 0-25% antimony oxide, 0-30% cupric oxide / cuprous oxide, 0-25% silicon oxide and 0-35% bismuth oxide. The particle size of the glass powder is 0.1-10 μm, preferably 0.3-5 μm, and more preferably 0.5-3 μm.

[0029] Preferably, the high molecular polymer is selected from one or more of ethyl cellulose, acrylic polymer, polyvinyl butyral, and polyamide, and the organic solvent is selected from one or more of butyl carbitol, butyl carbitol acetate, diethylene glycol butyl ether acetate, propylene glycol butyl ether, terpineol, tributyl citrate, and alcohol ester dodecahydrate.

[0030] Preferably, the organic auxiliary agent is silicone oil and / or a phosphate dispersant and / or an amine dispersant, and the particle size D50 of the silver powder is 1-3 μm.

[0031] Preferably, the binder of the organic carrier is prepared by mixing a high molecular weight polymer and an organic solvent, and dispersing and dissolving them. Preferably, the weight ratio of the high molecular weight polymer to the organic solvent is 1:2-20, preferably 1:4-10.

[0032] Preferably, the method for preparing a contact-enhanced N-type battery front silver paste comprises the following steps:

[0033] Pour the inorganic additives, micron- or nano-sized spherical silver powder, glass powder, organic carrier, and aluminum powder into a blender and mix them evenly with the organic additives to obtain the positive silver paste for N-type batteries.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] In the present invention, when preparing the silver paste, inorganic additives, micron- or nano-sized spherical silver powder, glass powder, organic carrier, and aluminum powder are poured into a blender and uniformly mixed with the organic additive to obtain the front silver paste for the N-type battery, wherein the inorganic additives for enhancing contact include FeF3 and / or K2SO3 and / or TiC and / or Mg2Si and / or MoO3 and / or graphene. These inorganic additives destroy the aluminum oxide layer wrapped around the outside of the aluminum powder, so that the aluminum powder can fully participate in the sintering process, thereby improving the contact performance of the battery cell and the fill factor, thereby obtaining a higher conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is an experimental data diagram of the present invention. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] Example 1

[0039] A contact-enhanced N-type battery front silver paste and a preparation method thereof, wherein the silver paste comprises the following components:

[0040] 0.01-10 parts by weight of an inorganic additive for enhancing contact;

[0041] 55-100 parts by weight of micron- or nano-sized spherical silver powder;

[0042] 0.1-20 parts by weight of glass powder;

[0043] 1-25 parts by weight of an organic carrier;

[0044] 0.1-10 parts by weight of aluminum powder;

[0045] 0.05-8 parts by weight of organic additives.

[0046] Example 2

[0047] A contact-enhanced N-type battery front silver paste and a preparation method thereof, wherein the silver paste comprises the following components:

[0048] 0.02-5 parts by weight of an inorganic additive for enhancing contact;

[0049] 75-95 parts by weight of micron- or nano-sized spherical silver powder;

[0050] 0.5-10 parts by weight of glass powder;

[0051] 3-20 parts by weight of an organic carrier;

[0052] 0.3-5 parts by weight of aluminum powder;

[0053] 0.1-5 parts by weight of organic additives.

[0054] Example 3

[0055] A contact-enhanced N-type battery front silver paste and a preparation method thereof, wherein the silver paste comprises the following components:

[0056] 0.5-2 parts by weight of an inorganic additive for enhancing contact;

[0057] 80-90 parts by weight of micron- or nano-sized spherical silver powder;

[0058] 1-6 parts by weight of glass powder;

[0059] 5-15 parts by weight of an organic carrier;

[0060] 0.5-3 parts by weight of aluminum powder;

[0061] 0.2-3 parts by weight of organic additives.

[0062] A method for preparing a front silver paste for an N-type battery with enhanced contact comprises: pouring an inorganic additive, micron- or nano-sized spherical silver powder, glass powder, an organic carrier, and aluminum powder into a blender, and uniformly mixing them with the organic additive to obtain a front silver paste for an N-type battery;

[0063] The preparation method of the glass powder is as follows: solid glass powder is weighed in proportion, mixed evenly, heated and kept warm, quenched, ball milled, and screened to obtain glass powder with a particle size of 0.2-12 μm, and the heating and holding temperature is 900-1600°C, and the heating and holding time is 40-140 minutes; deionized water is used for quenching; and the ball milling time is 2-15 hours.

[0064] In an embodiment of the present invention, the glass powder is composed of the following raw materials: 2-35% boron oxide, 0-6% aluminum oxide, 0-70% lead oxide, 2-30% zinc oxide, 5-50% barium oxide, 0-30% vanadium oxide, 0-25% antimony oxide, 0-30% copper oxide / cuprous oxide, 0-25% silicon oxide and 0-35% bismuth oxide. The particle size of the glass powder is 0.1-10 μm, preferably 0.3-5 μm, and more preferably 0.5-3 μm. The organic carrier is composed of 1-20% by weight of a polymer and 20-99% by weight of an organic solvent. The polymer is selected from One or more of ethyl cellulose, acrylic polymer, polyvinyl butyral, and polyamide; the organic solvent is selected from one or more of butyl carbitol, butyl carbitol acetate, diethylene glycol butyl ether acetate, propylene glycol butyl ether, terpineol, tributyl citrate, and alcohol ester dodecahydrate; the organic auxiliary agent is silicone oil and / or a phosphate dispersant and / or an amine dispersant; the particle size D50 of the silver powder is 1-3 μm; the binder of the organic carrier is prepared by mixing a high molecular weight polymer and an organic solvent, and dispersing and dissolving them; preferably, the weight ratio of the high molecular weight polymer to the organic solvent is 1:2-20, more preferably 1:4-10.

[0065] The inorganic auxiliary agent for enhancing contact is FeF3 and / or K2SO3 and / or TiC and / or Mg2Si and / or MoO3 and / or graphene;

[0066] Comparative Example 1: The aluminum powder content is 1.5 parts, and no inorganic additives are added;

[0067] Comparative Example 2: The aluminum powder content is 3 parts, and no inorganic additives are added;

[0068] Comparative Example 3: The aluminum powder content is 0.8 parts, and no inorganic additives are added;

[0069] Example 1: The aluminum powder content is 1.5 parts, and the inorganic additive FeF3 is added, 0.07 parts;

[0070] Example 2: The aluminum powder content is 1.5 parts, and the inorganic additive TiC is added, 0.1 parts;

[0071] Example 3: The aluminum powder content is 1.5 parts, and the inorganic additive K2SO3 is added, 0.1 parts;

[0072] Example 4: The aluminum powder content is 3 parts, and the inorganic additive FeF3 is added, 0.1 parts;

[0073] Example 5: The aluminum powder content is 0.8 parts, and the inorganic additive FeF3 is added, 0.05 parts;

[0074] Test experiment:

[0075]

[0076]

[0077] ① As can be seen from the table above, Comparative Examples 1 and 2 contain 1.5 and 3 parts of aluminum powder, respectively, and the other components are the same. In this case, the slurries containing 1.5 and 3 parts of aluminum powder have basically the same performance in electrical properties and contact resistance. The amount of aluminum powder does not significantly affect the slurry performance. The main reason is that most of the aluminum powder is limited by the influence of the aluminum oxide film and does not actually participate in the sintering reaction.

[0078] ②Comparative Example 3 also has a lower aluminum powder content than Example 5, but 0.05 parts of FeF3 are added. It can be clearly seen that the contact of Example 5 is significantly improved compared with Comparative Example 3, and the overall FF and Eff are significantly improved;

[0079] ③ Compared with Comparative Example 1, Examples 1 / 2 / 3 have the same aluminum powder content, and appropriate amounts of inorganic additives for enhancing contact are added to the three. It can be seen that the contact performance of Examples 1 / 2 / 3 is significantly improved, which is reflected in the obvious improvement of electrical performance FF and Eff.

[0080] ④ Compared with the comparative example 1, the contact performance, FF and Eff of Example 1 are also improved to a certain extent, but the Voc is slightly reduced. Compared with the results shown in ①, it can be seen from the test data in the table that the characteristics of aluminum powder increment are more easily manifested after adding a certain amount of inorganic additives that enhance contact.

[0081] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations coming within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A contact-enhanced N-type battery front silver paste, characterized in that: The silver paste consists of the following components: 0.01-10 parts by weight of an inorganic additive for enhancing contact; 55-100 parts by weight of micron- or nano-sized spherical silver powder; 0.1-20 parts by weight of glass powder; 1-25 parts by weight of an organic carrier; 0.1-10 parts by weight of aluminum powder; 0.05-8 parts by weight of organic additives.

2. The contact-enhanced N-type battery front silver paste according to claim 1, characterized in that: The silver paste consists of the following components: 0.02-5 parts by weight of an inorganic additive for enhancing contact; 75-95 parts by weight of micron- or nano-sized spherical silver powder; 0.5-10 parts by weight of glass powder; 3-20 parts by weight of an organic carrier; 0.3-5 parts by weight of aluminum powder; 0.1-5 parts by weight of organic additives.

3. The contact-enhanced N-type battery front silver paste according to claim 1, characterized in that: The silver paste consists of the following components: 0.5-2 parts by weight of an inorganic additive for enhancing contact; 80-90 parts by weight of micron- or nano-sized spherical silver powder; 1-6 parts by weight of glass powder; 5-15 parts by weight of an organic carrier; 0.5-3 parts by weight of aluminum powder; 0.2-3 parts by weight of organic additives.

4. The contact-enhanced N-type battery front silver paste according to claims 1-3, characterized in that: The inorganic auxiliary agent for enhancing contact is FeF3 and / or K2SO3 and / or TiC and / or Mg2Si and / or MoO3 and / or graphene.

5. The contact-enhanced N-type battery front silver paste according to claims 1-3, characterized in that: The glass powder is composed of the following raw materials: 2-35% boron oxide, 0-6% aluminum oxide, 0-70% lead oxide, 2-30% zinc oxide, 5-50% barium oxide, 0-30% vanadium oxide, 0-25% antimony oxide, 0-30% copper oxide / cuprous oxide, 0-25% silicon oxide and 0-35% bismuth oxide. The particle size of the glass powder is 0.1-10 μm, preferably 0.3-5 μm, and more preferably 0.5-3 μm.

6. The contact-enhanced N-type battery front silver paste according to claims 1-3, characterized in that: The organic carrier is composed of 1-20% by weight of a high molecular weight polymer and 20-99% by weight of an organic solvent, wherein the high molecular weight polymer is selected from one or more of ethyl cellulose, acrylic polymer, polyvinyl butyral, and polyamide, and the organic solvent is selected from one or more of butyl carbitol, butyl carbitol acetate, diethylene glycol butyl ether acetate, propylene glycol butyl ether, terpineol, tributyl citrate, and alcohol ester dodecanone.

7. The contact-enhanced N-type battery front silver paste according to claims 1-3, characterized in that: The organic auxiliary agent is silicone oil and / or a phosphate dispersant and / or an amine dispersant, and the particle size D50 of the silver powder is 1-3 μm.

8. The contact-enhanced N-type battery front silver paste according to claim 6, characterized in that: The preparation method of the binder of the organic carrier is: mixing a high molecular polymer and an organic solvent, dispersing and dissolving them; preferably, the weight ratio of the high molecular polymer to the organic solvent is 1:2-20, preferably 1:4-10.

9. A method for preparing a contact-enhanced N-type battery front silver paste according to any one of claims 1 to 8, characterized in that: The following steps are involved: Pour the inorganic additives, micron- or nano-sized spherical silver powder, glass powder, organic carrier, and aluminum powder into a blender and mix them evenly with the organic additives to obtain the positive silver paste for N-type batteries.

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