CN114203336B - HJT solar cell main fine grid general silver paste containing graphene and preparation method thereof - Google Patents

Abstract

The invention provides a HJT solar cell main fine grid general silver paste containing graphene, which is prepared from the following components in percentage by mass: 15-19% of micron-sized flake silver powder, 68-72% of submicron-sized spherical silver powder, 3-7% of nano-sized spherical silver powder, 0.12-0.16% of filler, 2-4% of resin, 0.1-0.2% of modifier, 3-5% of solvent, 0.1-0.2% of coupling agent, 0.1-0.2% of dispersing agent, 0.1-0.2% of curing agent, 0.1-0.2% of accelerator and 0.08-0.16% of wetting agent. The invention can realize the one-step printing of the main grid and the fine grid, reduce the overall resistivity, improve the adhesive force and ensure that the dispersibility, the thixotropy and the weather resistance of the sizing agent are better.

Description

HJT solar cell main fine grid general silver paste containing graphene and preparation method thereof

Technical Field

The invention relates to the technical field of solar cell metallization, in particular to HJT solar cell main fine grid general silver paste containing graphene and a preparation method thereof.

Background

Along with the continuous progress of photovoltaic cell technology, 2021 will start the trend of P-type to N-type iteration, and go to a higher efficiency step, the N-type technical route represented by TOPCon (Tunnel Oxide Passivating Contacts) tunnel oxide passivation contact battery, HJT (heteojunction WITH INTRINSIC THINFILM) Heterojunction battery is continuously broken through, and the industrialization process is expected to be accelerated. Compared with TOPCon, HJT has the advantages of better contact resistance and passivation effect, suitability for flaking, higher photoelectric conversion efficiency, capability of adapting to the requirements of the next-generation laminated battery, and the like. Currently HJT electrodes of batteries mainly adopt a screen printing process and use low-temperature cured conductive silver paste, wherein the low-temperature silver paste for fine grid printing needs to have lower volume resistance and contact resistance, high adhesive force, high aspect ratio and excellent weather resistance, and excellent printability; while low temperature silver paste for main grid printing is required to have good conductivity, printability and excellent tensile force.

Defects and deficiencies of the prior art:

1. the main fine grid is printed step by step, so that the production efficiency is reduced; two main and fine grid sizing agents are adopted for printing, so that the problem of mutual matching exists, and the reasons that the production line is abnormal and inconvenient to lock are caused;

2. the main grid requires excellent tensile force, so that the proportion of the resin needs to be properly increased, and the resistivity is increased;

3. The size and specific surface area of the nanosphere powder used by the fine grid and the unsuitable coupling agent and dispersant lead to poor contact resistance and adhesion, uneven dispersion and larger viscosity of slurry, thus reducing the curing reaction activity of the resin;

4. In order to ensure the printing height-width ratio, the thixotropic agent used cannot volatilize when being cured at low temperature, and remains in the electrode as impurities, so that the resistivity is improved;

5, the epoxy resin and the curing agent used are unsuitable, so that the contact position of the grid line and the surface of the silicon wafer is corroded by water mist and salt mist along with the time extension, the contact resistance is obviously increased, the adhesive force is reduced, and the weather resistance of the grid line is poor.

Disclosure of Invention

In order to solve the problems, the invention discloses HJT solar cell main fine grid general silver paste containing graphene and a preparation method thereof, which not only can realize one-step printing of main and fine grids, but also can reduce the overall resistivity, improve the adhesive force and ensure that the dispersibility, the thixotropic property and the weather resistance of the paste are better.

The specific scheme is as follows:

The common silver paste containing the main fine grid of the graphene HJT solar cell is characterized in that: the composite material is prepared from the following components in percentage by mass: 15-19% of micron-sized flake silver powder, 68-72% of submicron-sized spherical silver powder, 3-7% of nano-sized spherical silver powder, 0.12-0.16% of filler, 2-4% of resin, 0.1-0.2% of modifier, 3-5% of solvent, 0.1-0.2% of coupling agent, 0.1-0.2% of dispersing agent, 0.1-0.2% of curing agent, 0.1-0.2% of accelerator and 0.08-0.16% of wetting agent.

As a further improvement of the present invention, the micron-sized plate-like silver powder is D50:1-5 μm, the submicron spherical silver powder is D50:0.2-0.5 mu m, wherein the nano-scale spherical silver powder is D50:10-50nm.

As a further improvement of the invention, the filler is one or two of hydroxylated graphene and carboxylated graphene, wherein the sheet diameter of the carboxylated graphene is 0.5-5 mu m, and the thickness is 0.8-1.2nm.

As a further improvement of the present invention, the resin is one or more of bisphenol a epoxy resin, bisphenol F epoxy resin, carboxyl terminated polyester resin, carboxyl acrylic resin.

As a further improvement of the invention, the modifier is one or more of acrylic acid, gallic acid, methyl dehydroabietate, dehydroabietic acid, oleic acid, 3', 5' -tetramethyl biphenol.

As a further improvement of the invention, the solvent is one or more of butyl carbitol, butyl carbitol acetate, terpineol, alcohol ester twelve, tributyl citrate and diethylene glycol butyl ether.

As a further improvement of the invention, the coupling agent is one or more of silane coupling agents a151, a171, a 172.

As a further improvement of the invention, the dispersing agent is one or more of octyl phenyl polyoxyethylene ether, N-methyl pyrrolidone and polyethylene glycol oleate.

As a further improvement of the invention, the curing agent is one or more of triglycidyl isocyanurate, beta-hydroxyalkylamide, acrylic acid modified hydroxyalkylamide and oleic acid modified hydroxyalkylamide.

As a further improvement of the invention, the accelerator is one or more of carboxylate, methyl hydrazine and amino imine.

As a further improvement of the invention, the wetting agent is one or more of 2.4.7.9-tetramethyl-5-decyne-4.7-diol, oleamide propyl dimethylamine, trimethyl butylene glycol, oleyl alcohol polyoxyethylene ether and fluorine surfactant FC-4430.

A preparation method of a common silver paste containing HJT solar cell main fine grid of graphene is characterized by comprising the following steps: the method comprises the following specific steps:

Slowly pouring the nano-scale spherical silver powder into a solvent along the wall of a beaker by adopting a constant-temperature stirrer, setting the rotating speed to 600rpm, the temperature to 25 ℃, stirring for 1 hour, then mixing by using a centrifugal machine, and uniformly mixing at the rotating speed of 1200rpm and the temperature to 25 ℃ for 30 minutes to obtain a first mixture;

Step (2) adopting a constant-temperature stirrer, setting the rotating speed to 600rpm, setting the temperature to 60 ℃, adding resin, introducing N2 gas into the bottom of a beaker, sequentially adding a wetting agent, a dispersing agent and a coupling agent into the beaker, slowly adding a filler after uniformly stirring, stirring for 1 hour, and cooling to normal temperature to obtain a second mixture;

sequentially and slowly adding the second mixture, the modifier, the curing agent and the accelerator into the first mixture by adopting a constant-temperature stirrer at normal temperature, setting the rotating speed to 600rpm, stirring for 1 hour, using a centrifugal machine to rotate at 1200rpm and the temperature of 25 ℃ for 30 minutes, and uniformly mixing to obtain a third mixture;

Step (4), adding micron-sized flake silver powder and submicron-sized spherical silver powder into the third mixture, mixing by using a three-roller machine, setting the rotating speed to 750rpm, and mixing for 3 times in the first step, wherein the initial roller gap is 60 mu m and the final roller gap is 30 mu m; secondly, mixing for 3 times, wherein the initial roller gap is 30 mu m and the final roller gap is 15 mu m; thirdly, mixing for 5 times, wherein the initial roller gap is 15 mu m and the final roller gap is 7 mu m; fourth, the initial roller gap is 10 μm and the final roller gap is 4 μm, and the mixture is mixed for 6 times, so that the mixture is uniformly dispersed, and the finished silver paste is obtained.

The invention has the beneficial effects that:

1. Compared with common graphene, the hydroxylated or carboxylated graphene has larger affinity to polar molecules and is easier to disperse in a carrier taking epoxy resin as a main body;

2. The graphene is used as a core, the dot-shaped spherical nano silver powder and the flake silver powder are compounded, a proper dispersing agent is added, a proper dispersing method is adopted, and the excellent electric conductivity, heat conductivity and flexible flake structure of the graphene are utilized, so that efficient point, line and surface contact can be formed on the whole epoxy resin system, a three-dimensional conductive network is formed, the volume resistance can be reduced, and meanwhile, larger tensile force is provided;

3. The graphene has a large diameter-thickness ratio, and the thixotropic property of silver paste can be improved by adding a small amount of graphene, so that better aspect ratio and conversion efficiency are obtained;

4. From the thermal performance, the graphene is the material with the highest thermal conductivity known at present, and the heat resistance of the epoxy resin can be improved by adding the graphene as a filler, so that the epoxy resin is more compact in crosslinking after being cured, the graphene is more compact in shrinkage, and the thermal shock resistance is better;

5. Due to the small-size effect and the two-dimensional lamellar structure of the graphene, the defects in the epoxy resin coating can be improved, so that a compact isolation layer can be formed in the coating, the water-proof effect is improved, the self-corrosion current density is reduced, and the corrosion resistance, the salt resistance and the like are improved;

6. proper dispersing agents are selected, and the dispersing uniformity is improved by adopting octyl phenyl polyoxyethylene ether, N-methyl pyrrolidone and polyethylene glycol oleate;

7. selecting proper silane coupling agents A151, A171 and A172, and improving the jointing property and compatibility between graphene and epoxy resin;

8. The bubbling and stirring are used together, so that the dispersibility is better.

Detailed Description

The present invention will be further elucidated with reference to the following embodiments, which should be understood as merely illustrative of the invention and not as limiting the scope of the invention.

Example 1

The HJT solar cell main fine grid general silver paste containing graphene is prepared from the following components in percentage by mass:

Micron-sized plate-like silver powder (D50:1 μm): 15%

Submicron spherical silver powder (d50:0.2 μm): 72 percent of

Nanoscale spherical silver powder (d50:10 nm): 5%

And (3) filling: hydroxylated graphene (sheet diameter 0.5-5 μm, thickness 0.8-1.2 nm): 0.14%

Resin: bisphenol A epoxy resin 2%

And (3) a modifier: acrylic acid: 0.1%

Solvent: butyl carbitol: 5%

Coupling agent: silane coupling agent a151:0.1%

Dispersing agent: octyl phenyl polyoxyethylene ether: 0.1%

Curing agent: triglycidyl isocyanurate: 0.2%

And (3) an accelerator: carboxylic acid esters: 0.2%

Wetting agent: 2.4.7.9-tetramethyl-5-decyne-4.7-diol: 0.16%

A preparation method of HJT solar cell main fine grid general silver paste containing graphene comprises the following specific steps:

And (2) slowly pouring the nano-scale spherical silver powder into the solvent along the wall of the beaker by adopting a constant-temperature stirrer, wherein the rotating speed is set to 600rpm, the temperature is 25 ℃, and the stirring time is 1 hour. Then, the mixture was mixed by using a centrifuge at a rotation speed of 1200rpm at a temperature of 25℃for 30 minutes. Uniformly mixing to obtain a first mixture;

Step (2) adopting a constant-temperature stirrer, setting the rotating speed to 600rpm, setting the temperature to 60 ℃, adding resin, introducing N2 gas into the bottom of a beaker, sequentially adding a wetting agent, a dispersing agent and a coupling agent into the beaker, slowly adding a filler after uniformly stirring, stirring for 1 hour, and cooling to normal temperature to obtain a second mixture;

sequentially and slowly adding the second mixture, the modifier, the curing agent and the accelerator into the first mixture by adopting a constant-temperature stirrer at normal temperature, setting the rotating speed to 600rpm, stirring for 1 hour, using a centrifugal machine to rotate at 1200rpm and the temperature of 25 ℃ for 30 minutes, and uniformly mixing to obtain a third mixture;

And (4) finally adding the micron-sized flake silver powder and the submicron-sized spherical silver powder into the third mixture, mixing by using a three-roller machine, and setting the rotating speed to 750rpm. The first step, the initial roller gap is 60 mu m and the final roller gap is 30 mu m, and the mixing is carried out for 3 times; secondly, mixing for 3 times, wherein the initial roller gap is 30 mu m and the final roller gap is 15 mu m; thirdly, mixing for 5 times, wherein the initial roller gap is 15 mu m and the final roller gap is 7 mu m; fourth, the initial roll gap 10 μm and the final roll gap 4 μm were mixed 6 times. So as to uniformly disperse and obtain the finished silver paste.

Example 2

The HJT solar cell main fine grid general silver paste containing graphene is prepared from the following components in percentage by mass:

micron-sized plate-like silver powder (D50:5 μm): 16%

Submicron spherical silver powder (d50:0.5 μm): 69%

Nanoscale spherical silver powder (d50:50 nm): 7%

And (3) filling: carboxylated graphene (sheet diameter 0.5-5 μm, thickness 0.8-1.2 nm): 0.16%

Resin: bisphenol F epoxy resin: 2.5%

And (3) a modifier: gallic acid: 0.12%

Solvent: butyl carbitol acetate: 4.5%

Coupling agent: silane coupling agent a171:0.12%

Dispersing agent: n-methylpyrrolidone: 0.12%

Curing agent: beta-hydroxyalkylamide: 0.17%

And (3) an accelerator: methyl hydrazine: 0.17%

Wetting agent: oleamide propyldimethylamine: 0.14%

A preparation method of HJT solar cell main fine grid general silver paste containing graphene comprises the following specific steps:

And (2) slowly pouring the nano-scale spherical silver powder into the solvent along the wall of the beaker by adopting a constant-temperature stirrer, wherein the rotating speed is set to 600rpm, the temperature is 25 ℃, and the stirring time is 1 hour. Then, the mixture was mixed by using a centrifuge at a rotation speed of 1200rpm at a temperature of 25℃for 30 minutes. Uniformly mixing to obtain a first mixture;

Step (2) adopting a constant-temperature stirrer, setting the rotating speed to 600rpm, setting the temperature to 60 ℃, adding resin, introducing N2 gas into the bottom of a beaker, sequentially adding a wetting agent, a dispersing agent and a coupling agent into the beaker, slowly adding a filler after uniformly stirring, stirring for 1 hour, and cooling to normal temperature to obtain a second mixture;

sequentially and slowly adding the second mixture, the modifier, the curing agent and the accelerator into the first mixture by adopting a constant-temperature stirrer at normal temperature, setting the rotating speed to 600rpm, stirring for 1 hour, using a centrifugal machine to rotate at 1200rpm and the temperature of 25 ℃ for 30 minutes, and uniformly mixing to obtain a third mixture;

And (4) finally adding the micron-sized flake silver powder and the submicron-sized spherical silver powder into the third mixture, mixing by using a three-roller machine, and setting the rotating speed to 750rpm. The first step, the initial roller gap is 60 mu m and the final roller gap is 30 mu m, and the mixing is carried out for 3 times; secondly, mixing for 3 times, wherein the initial roller gap is 30 mu m and the final roller gap is 15 mu m; thirdly, mixing for 5 times, wherein the initial roller gap is 15 mu m and the final roller gap is 7 mu m; fourth, the initial roll gap 10 μm and the final roll gap 4 μm were mixed 6 times. So as to uniformly disperse and obtain the finished silver paste.

Example 3

The HJT solar cell main fine grid general silver paste containing graphene is prepared from the following components in percentage by mass:

Micron-sized plate-like silver powder (D50:3 μm): 17%

Submicron spherical silver powder (d50:0.3 μm): 71%

Nanoscale spherical silver powder (d50:30 nm): 4%

And (3) filling: carboxylated graphene (one or two of sheet diameter 0.5-5 μm, thickness 0.8-1.2 nm): 0.13%

Resin: carboxyl-terminated polyester resin: 3%

And (3) a modifier: dehydroabietic acid methyl ester: 0.15%

Solvent: terpineol: 4%

Coupling agent: one or more of the silane coupling agents A172: 0.15%

Dispersing agent: polyethylene glycol oleate: 0.15%

Curing agent: acrylic modified hydroxyalkylamide: 0.15%

And (3) an accelerator: amino imine: 0.15%

Wetting agent: trimethylbutenediol: 0.12%

A preparation method of HJT solar cell main fine grid general silver paste containing graphene comprises the following specific steps:

And (2) slowly pouring the nano-scale spherical silver powder into the solvent along the wall of the beaker by adopting a constant-temperature stirrer, wherein the rotating speed is set to 600rpm, the temperature is 25 ℃, and the stirring time is 1 hour. Then, the mixture was mixed by using a centrifuge at a rotation speed of 1200rpm at a temperature of 25℃for 30 minutes. Uniformly mixing to obtain a first mixture;

Step (2) adopting a constant-temperature stirrer, setting the rotating speed to 600rpm, setting the temperature to 60 ℃, adding resin, introducing N2 gas into the bottom of a beaker, sequentially adding a wetting agent, a dispersing agent and a coupling agent into the beaker, slowly adding a filler after uniformly stirring, stirring for 1 hour, and cooling to normal temperature to obtain a second mixture;

sequentially and slowly adding the second mixture, the modifier, the curing agent and the accelerator into the first mixture by adopting a constant-temperature stirrer at normal temperature, setting the rotating speed to 600rpm, stirring for 1 hour, using a centrifugal machine to rotate at 1200rpm and the temperature of 25 ℃ for 30 minutes, and uniformly mixing to obtain a third mixture;

And (4) finally adding the micron-sized flake silver powder and the submicron-sized spherical silver powder into the third mixture, mixing by using a three-roller machine, and setting the rotating speed to 750rpm. The first step, the initial roller gap is 60 mu m and the final roller gap is 30 mu m, and the mixing is carried out for 3 times; secondly, mixing for 3 times, wherein the initial roller gap is 30 mu m and the final roller gap is 15 mu m; thirdly, mixing for 5 times, wherein the initial roller gap is 15 mu m and the final roller gap is 7 mu m; fourth, the initial roll gap 10 μm and the final roll gap 4 μm were mixed 6 times. So as to uniformly disperse and obtain the finished silver paste.

Example 4

The HJT solar cell main fine grid general silver paste containing graphene is prepared from the following components in percentage by mass:

micron-sized plate-like silver powder (D50:2 μm): 18%

Submicron spherical silver powder (d50:0.3 μm): 68%

Nanoscale spherical silver powder (d50:20 nm): 6%

And (3) filling: hydroxylated graphene (sheet diameter 0.5-5 μm, thickness 0.8-1.2 nm): 0.15%

Resin: 3.5% of carboxyl acrylic resin

And (3) a modifier: dehydroabietic acid: 0.17%

Solvent: alcohol ester twelve: 3.5%

Coupling agent: silane coupling agent a151:0.08%, A171:0.09%

Dispersing agent: octyl phenyl polyoxyethylene ether 0.08 percent, N-methyl pyrrolidone 0.09 percent

Curing agent: oleic acid modified hydroxyalkylamide: 0.12%

And (3) an accelerator: carboxylate 0.06%, methyl hydrazine 0.06%

Wetting agent: oleyl alcohol polyoxyethylene ether 0.1%

A preparation method of HJT solar cell main fine grid general silver paste containing graphene comprises the following specific steps:

And (2) slowly pouring the nano-scale spherical silver powder into the solvent along the wall of the beaker by adopting a constant-temperature stirrer, wherein the rotating speed is set to 600rpm, the temperature is 25 ℃, and the stirring time is 1 hour. Then, the mixture was mixed by using a centrifuge at a rotation speed of 1200rpm at a temperature of 25℃for 30 minutes. Uniformly mixing to obtain a first mixture;

Step (2) adopting a constant-temperature stirrer, setting the rotating speed to 600rpm, setting the temperature to 60 ℃, adding resin, introducing N2 gas into the bottom of a beaker, sequentially adding a wetting agent, a dispersing agent and a coupling agent into the beaker, slowly adding a filler after uniformly stirring, stirring for 1 hour, and cooling to normal temperature to obtain a second mixture;

sequentially and slowly adding the second mixture, the modifier, the curing agent and the accelerator into the first mixture by adopting a constant-temperature stirrer at normal temperature, setting the rotating speed to 600rpm, stirring for 1 hour, using a centrifugal machine to rotate at 1200rpm and the temperature of 25 ℃ for 30 minutes, and uniformly mixing to obtain a third mixture;

And (4) finally adding the micron-sized flake silver powder and the submicron-sized spherical silver powder into the third mixture, mixing by using a three-roller machine, and setting the rotating speed to 750rpm. The first step, the initial roller gap is 60 mu m and the final roller gap is 30 mu m, and the mixing is carried out for 3 times; secondly, mixing for 3 times, wherein the initial roller gap is 30 mu m and the final roller gap is 15 mu m; thirdly, mixing for 5 times, wherein the initial roller gap is 15 mu m and the final roller gap is 7 mu m; fourth, the initial roll gap 10 μm and the final roll gap 4 μm were mixed 6 times. So as to uniformly disperse and obtain the finished silver paste.

Example 5

The HJT solar cell main fine grid general silver paste containing graphene is prepared from the following components in percentage by mass:

micron-sized plate-like silver powder (D50:4 μm): 19%

Submicron spherical silver powder (d50:0.4 μm): 70 percent of

Nanoscale spherical silver powder (d50:40 nm): 3%

And (3) filling: 0.06% of hydroxylated graphene and 0.8-1.2 nm of carboxylated graphene (with a sheet diameter of 0.5-5 μm: 0.06%

Resin: bisphenol F epoxy resin 2%, carboxyl acrylic resin 2%

And (3) a modifier: oleic acid 0.2%

Solvent: tributyl citrate 3%

Coupling agent: silane coupling agent a171:0.1%, A172:0.1%

Dispersing agent: 0.1% of N-methylpyrrolidone and 0.1% of polyethylene glycol oleate

Curing agent: beta-hydroxyalkylamide 0.05%, acrylic acid modified hydroxyalkylamide 0.05%

And (3) an accelerator: methyl hydrazine 0.05 percent and amino imine 0.05 percent

Wetting agent: fluorine surfactant FC-4430:0.08%

A preparation method of HJT solar cell main fine grid general silver paste containing graphene comprises the following specific steps:

And (2) slowly pouring the nano-scale spherical silver powder into the solvent along the wall of the beaker by adopting a constant-temperature stirrer, wherein the rotating speed is set to 600rpm, the temperature is 25 ℃, and the stirring time is 1 hour. Then, the mixture was mixed by using a centrifuge at a rotation speed of 1200rpm at a temperature of 25℃for 30 minutes. Uniformly mixing to obtain a first mixture;

Step (2) adopting a constant-temperature stirrer, setting the rotating speed to 600rpm, setting the temperature to 60 ℃, adding resin, introducing N2 gas into the bottom of a beaker, sequentially adding a wetting agent, a dispersing agent and a coupling agent into the beaker, slowly adding a filler after uniformly stirring, stirring for 1 hour, and cooling to normal temperature to obtain a second mixture;

sequentially and slowly adding the second mixture, the modifier, the curing agent and the accelerator into the first mixture by adopting a constant-temperature stirrer at normal temperature, setting the rotating speed to 600rpm, stirring for 1 hour, using a centrifugal machine to rotate at 1200rpm and the temperature of 25 ℃ for 30 minutes, and uniformly mixing to obtain a third mixture;

And (4) finally adding the micron-sized flake silver powder and the submicron-sized spherical silver powder into the third mixture, mixing by using a three-roller machine, and setting the rotating speed to 750rpm. The first step, the initial roller gap is 60 mu m and the final roller gap is 30 mu m, and the mixing is carried out for 3 times; secondly, mixing for 3 times, wherein the initial roller gap is 30 mu m and the final roller gap is 15 mu m; thirdly, mixing for 5 times, wherein the initial roller gap is 15 mu m and the final roller gap is 7 mu m; fourth, the initial roll gap 10 μm and the final roll gap 4 μm were mixed 6 times. So as to uniformly disperse and obtain the finished silver paste.

Comparison results

1. Tension and weatherability are compared, see table below:

The tensile force of the examples shown in the above table is greater than that of the comparative examples, and the contact resistance change in the weather resistance test is also smaller than that of the comparative examples.

2. Slurry viscosity contrast

The viscosity of the examples shown in the table above is lower than that of the comparative examples, and the thixotropic value and the aspect ratio are larger, so that the printing property is better.

3. Battery performance comparison

The performance of the HJT solar cell containing graphene after the preparation of the above embodiment is shown in the following table:

Through the table, the HJT solar cell main fine grid general silver paste containing graphene of the embodiment has excellent performances such as conductivity, printability and conversion efficiency, and can meet the requirements of a main stream HJT solar cell screen printing grid.

The HJT solar cell main fine grid general silver paste containing the graphene in the embodiment can form smaller resistivity, higher conversion efficiency and tensile force and better weather resistance by adopting submicron and nanometer spherical silver powder and the graphene.

The functionalized graphene, namely the hydroxylated or carboxylated graphene is adopted, so that the compatibility of the graphene in epoxy resin is improved; proper dispersing agents are selected, and the dispersing uniformity is improved by adopting octyl phenyl polyoxyethylene ether, N-methyl pyrrolidone and polyethylene glycol oleate; selecting proper silane coupling agents A151, A171 and A172, and improving the jointing property and compatibility between graphene and epoxy resin; the bubbling and stirring are used together, so that the dispersibility is better.

The technical means disclosed by the scheme of the invention is not limited to the technical means disclosed by the embodiment, and also comprises the technical scheme formed by any combination of the technical features. It should be noted that modifications and adaptations to the invention may occur to one skilled in the art without departing from the principles of the present invention and are intended to be within the scope of the present invention.

Claims (1)

1. The common silver paste containing the main fine grid of the graphene HJT solar cell is characterized in that: the composite material is prepared from the following components in percentage by mass: 15-19% of micron-sized flake silver powder, 68-72% of submicron-sized spherical silver powder, 3-7% of nano-sized spherical silver powder, 0.12-0.16% of filler, 2-4% of resin, 0.1-0.2% of modifier, 3-5% of solvent, 0.1-0.2% of coupling agent, 0.1-0.2% of dispersing agent, 0.1-0.2% of curing agent, 0.1-0.2% of accelerator and 0.08-0.16% of wetting agent; the micron-sized flake silver powder is D50:1-5 μm, the submicron spherical silver powder is D50:0.2-0.5 mu m, wherein the nano-scale spherical silver powder is D50:10-50nm; the filler is one or two of hydroxylated graphene and carboxylated graphene, wherein the sheet diameter of the carboxylated graphene is 0.5-5 mu m, and the thickness is 0.8-1.2nm; the resin is one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, carboxyl end-capped polyester resin and carboxyl acrylic resin; the modifier is one or more of acrylic acid, gallic acid, dehydroabietic acid methyl ester, dehydroabietic acid, oleic acid, 3', 5' -tetramethyl biphenyl diphenol; the solvent is one or more of butyl carbitol, butyl carbitol acetate, terpineol, alcohol ester twelve, tributyl citrate and diethylene glycol butyl ether; the coupling agent is one or more of silane coupling agents A151, A171 and A172; the dispersing agent is one or more of octyl phenyl polyoxyethylene ether, N-methyl pyrrolidone and polyethylene glycol oleate; the curing agent is one or more of triglycidyl isocyanurate, beta-hydroxyalkylamide, acrylic acid modified hydroxyalkylamide and oleic acid modified hydroxyalkylamide; the accelerator is one or more of carboxylate, methyl hydrazine and amino imine; the wetting agent is one or more of 2.4.7.9-tetramethyl-5-decyne-4.7-diol, oleamide propyl dimethylamine, trimethyl butylene glycol, oleyl alcohol polyoxyethylene ether and fluorine surfactant FC-4430; the preparation method of the HJT solar cell main fine grid general silver paste containing graphene comprises the following specific steps:

Slowly pouring the nano-scale spherical silver powder into a solvent along the wall of a beaker by adopting a constant-temperature stirrer, setting the rotating speed to 600rpm, the temperature to 25 ℃, stirring for 1 hour, then mixing by using a centrifugal machine, and uniformly mixing at the rotating speed of 1200rpm and the temperature to 25 ℃ for 30 minutes to obtain a first mixture;

Step (2) adopting a constant-temperature stirrer, setting the rotating speed to 600rpm, setting the temperature to 60 ℃, adding resin, introducing N2 gas into the bottom of a beaker, sequentially adding a wetting agent, a dispersing agent and a coupling agent into the beaker, slowly adding a filler after uniformly stirring, stirring for 1 hour, and cooling to normal temperature to obtain a second mixture;

sequentially and slowly adding the second mixture, the modifier, the curing agent and the accelerator into the first mixture by adopting a constant-temperature stirrer at normal temperature, setting the rotating speed to 600rpm, stirring for 1 hour, using a centrifugal machine to rotate at 1200rpm and the temperature of 25 ℃ for 30 minutes, and uniformly mixing to obtain a third mixture;

Step (4), adding micron-sized flake silver powder and submicron-sized spherical silver powder into the third mixture, mixing by using a three-roller machine, setting the rotating speed to 750rpm, and mixing for 3 times in the first step, wherein the initial roller gap is 60 mu m and the final roller gap is 30 mu m; secondly, mixing for 3 times, wherein the initial roller gap is 30 mu m and the final roller gap is 15 mu m; thirdly, mixing for 5 times, wherein the initial roller gap is 15 mu m and the final roller gap is 7 mu m; fourth, the initial roller gap is 10 μm and the final roller gap is 4 μm, and the mixture is mixed for 6 times, so that the mixture is uniformly dispersed, and the finished silver paste is obtained.