CN111261730A - Front electrode of N-type efficient TOPCon battery - Google Patents

Abstract

The invention discloses a front electrode of an N-type high-efficiency TOPCon battery, comprising a plurality of thin grid lines and a plurality of main grid lines. Both ends of the busbar line segment are forked to form two branch lines; the number of the thin gate lines is 95-105. The invention can cooperate with the existing high-efficiency N-type TOPCon process to improve the battery efficiency; reduce the consumption of the front metal paste in the production, and reduce the production cost; meanwhile, it can cooperate with the new process at the downstream component end to improve the component production yield and component power.

Description

A front electrode of an N-type high-efficiency TOPCon battery

technical field

The invention relates to an electrode design of a solar cell, in particular to a front electrode of an N-type high-efficiency TOPCon cell, which belongs to the technical field of solar cells.

Background technique

In the photovoltaic industry, the forming of electrodes is mainly realized by screen printing, using the basic principle that some meshes of the screen pattern are transparent to the paste, and some meshes are not transparent to the paste. When printing, pour the paste at one end of the screen, apply a certain pressure to the paste part of the screen with a scraper, and move towards the other end of the screen at the same time, the paste is squeezed from the mesh of the graphic part by the scraper during the movement. on the substrate. During the printing process, the squeegee is always in line contact with the screen printing plate and the substrate, and the contact line moves with the movement of the squeegee, while other parts of the screen are separated from the substrate, which ensures the dimensional accuracy of printing and avoids smearing the substrate. When the squeegee scrapes the entire printing area and then lifts up, the screen is also separated from the substrate, and the slurry is gently scraped back to the initial position by the ink return knife, and the worktable returns to the feeding position, which is a complete printing stroke.

The printing screen occupies a very important part in the screen printing process, of which the screen graphic design is the key. According to the different needs of the product, the screen graphic can be adjusted and designed accordingly; Adjusting the shape of the graphic can reduce the unit consumption of printing, thereby reducing the total consumption of precious metals in production and reducing the cost; in addition, designing the graphic shape according to the supporting battery process can improve the conversion efficiency of the cell to a certain extent; finally, special design The graphics can be matched with the downstream component end process to improve the production yield and power of solar components. Therefore, the graphic design of the printed screen is critical to the performance of the battery.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned problems, the present invention provides a front electrode of an N-type high-efficiency TOPCon battery. By designing the front-side electrode of the N-type high-efficiency TOPCon battery, the performance of the solar cell is improved and the production cost is reduced.

For this reason, the present invention adopts following technical scheme:

A front electrode of an N-type high-efficiency TOPCon battery includes a plurality of thin grid lines and a plurality of busbar lines, at least one of the busbar lines is composed of at least two busbar line segments arranged at intervals, and each busbar line segment is Both ends are forked to form two branch lines; the number of the thin grid lines is 95-105. The number of thin grid lines is 95-105, which can improve the Voc and Isc of the battery's electrical performance, and can ensure that the fill factor FF of the battery reaches an ideal value, thereby improving the overall conversion efficiency of the battery.

Preferably, the busbar line is composed of two equal busbar line segments, and the midpoint of the interval between the two busbar line segments is located on the centerline of the battery sheet. In this way, the center line is formed in the middle part of the electrode pattern of the battery, which cooperates with the half-cutting process of the battery slice, and can be combined with the process improvement of the module end to reduce the defective welding rate of the module and improve the overall power generation power of the module.

Preferably, the width of the main gate line is 0.07 μm, and the width of the branch line is 0.05 μm. This width can ensure the tensile force of the printing paste and the reliability of the module paste are qualified, and at the same time, it can reduce the paste consumption of a single printed cell, reduce the cost, and improve the conversion efficiency of the cell.

Preferably, a plurality of PAD solder joints are arranged on the busbar line, the size of each PAD solder joint is different, and the distance between adjacent PAD solder joints is different in size. Combined with the improvement of component end welding technology, welding defects can be reduced and the production yield of component products can be improved.

Preferably, there is an anti-break gate design at the intersection of the busbar line and the thin gate line. Reduce the loss of cell efficiency due to poor printed grids in the actual production process.

Preferably, the anti-break grid is designed such that the thin grid lines and the intersection of the thin grid lines and the busbar lines gradually taper from the intersection to the distal end, forming an isosceles trapezoid structure. Reduce the loss of cell efficiency due to poor printed grids in the actual production process.

Preferably, the thin grid lines at the connection between the thin grid lines and the PAD pads do not penetrate the PAD pads. The fact that the fine grid does not penetrate the PAD point can effectively reduce the influence of the fine grid paste on the PAD point of the busbar, and optimize the welding effect of the component.

Preferably, there are annular marking points on the thin grid lines, and corresponding solid graphic marking points on the main grid lines.

Preferably, there are circular marking points on the thin grid lines, and corresponding solid circular marking points on the main grid lines, the diameter of the ring is 0.8um, and the diameter of the circle is 0.8um.

On the premise that the size of the marking point can ensure the recognition of the component end, the area as small as possible can reduce the shading area on the front of the battery, increase the short-circuit current Isc of the battery, and reduce the unit consumption of the front busbar paste, reducing the production cost. The position of the mark point is determined by the improvement of the component process, which further optimizes the component welding and reduces the defect rate.

Combined with the process improvement at the component end, the present invention can reduce the poor welding of the component and improve the overall power generation of the component. It is better to adopt intermittent arrangement in the middle part. Preferably, the busbar line segment is two sections, and the two busbar line segments are symmetrically arranged. .

To sum up, compared with the prior art, the beneficial effects of the present invention are embodied in:

1. It can cooperate with the existing high-efficiency N-type TOPCon process to achieve the purpose of improving battery efficiency;

2. It can reduce the consumption of positive metal slurry in production and achieve the purpose of reducing production cost;

3. It can cooperate with the new process of downstream components to achieve the purpose of improving component production yield and component power.

Description of drawings

1 is a schematic structural diagram of a busbar in the present invention;

2 is a schematic diagram of a busbar marking point and a busbar PAD point in the present invention;

3 is a schematic diagram of a busbar end structure in the present invention;

FIG. 4 is a schematic diagram of the design of the busbar and the thin grid anti-break barrier and the design of the connection between the thin grid and the PAD point in the present invention.

In the figure, 1 is the main grid line, 11 is the main grid line segment, 12 is the branch line, 2 is the thin grid line, 3 is the PAD solder joint, 4 is the isosceles trapezoid structure, 5 is the ring mark point, and 6 is the solid figure Mark the point.

Detailed ways

The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

As shown in FIG. 1 , the front electrode of the N-type high-efficiency TOPCon battery of the present invention includes a plurality of thin grid lines 2 and a plurality of busbar lines 1 , at least one of the busbar lines 1 is formed by at least two sections spaced apart. It is composed of busbar line segments 11 , and both ends of each busbar line segment 11 are forked to form two branch lines 12 ; the number of thin grid lines 2 is 95-105.

In different embodiments, different numbers of busbar line segments 11 may be designed. In this embodiment, in order to cooperate with the battery slice halving technology, the busbar 1 is composed of two equal busbar segments 11 , and the midpoint of the interval between the two busbar segments is located on the centerline of the battery slice. In this way, the center line is formed in the middle part of the electrode pattern of the battery, which facilitates the half-cutting operation of the battery sheet. At the same time, it reduces the defective rate of component welding and improves the overall power generation of the component.

As shown in FIG. 3 , the width D1 of the bus line 1 is 0.07 μm, and the width D2 of the branch line 12 is 0.05 μm. This width can ensure the tensile force of the printing paste and the reliability of the module paste are qualified, and at the same time, it can reduce the paste consumption of a single printed cell, reduce the cost, and improve the conversion efficiency of the cell.

As shown in FIG. 1 and FIG. 2 , a plurality of PAD solder joints 3 are arranged on the busbar 1 , and the dimensions of each PAD solder joint are different.

As shown in FIG. 4 , there is an anti-break gate design at the intersection of the busbar line 1 and the thin grid line 2 . Specifically, the anti-break gate is designed such that on the thin grid line 2 , the intersection of the thin grid line 2 and the busbar line 1 is gradually tapered from the intersection to the distal end, forming an isosceles trapezoid structure 4 . The thin grid lines at the connection between the thin grid lines 2 and the PAD pads 3 do not penetrate the PAD pads. The fact that the fine grid does not penetrate the PAD point can effectively reduce the influence of the fine grid paste on the PAD point of the busbar, and optimize the welding effect of the component.

As shown in FIG. 2 and FIG. 4 , there are annular marking points 5 on the thin grid lines 2 , and corresponding solid graphic marking points 6 on the main grid lines. Preferably, there are circular marking points on the thin grid lines, and corresponding solid circular marking points on the main grid lines, the diameter of the ring is 0.8um, and the diameter of the circle is 0.8um.

After testing, the effects of the TOPCon battery using the front electrode of the N-type high-efficiency TOPCon battery of the present invention and the common battery are shown in Table 1 and Table 2.

Table 1: Comparison of printing paste unit consumption

Table 2: Comparison of cell efficiency improvement

Claims (9)

1. A front electrode of an N-type high-efficiency TOPCon battery, comprising a plurality of thin grid lines and a plurality of busbar lines, at least one of the busbar lines is composed of at least two busbar line segments arranged at intervals, and each busbar Both ends of the line segment are split to form two branch lines; the number of the thin grid lines is 95-105. 2. The front electrode of the N-type high-efficiency TOPCon battery according to claim 1, wherein the busbar line is composed of two equal busbar line segments, and the midpoint of the interval between the two busbar line segments is located at on the centerline of the cell. 3 . The front electrode of an N-type high-efficiency TOPCon battery according to claim 1 , wherein the width of the busbar line is 0.07 μm, and the width of the branch line is 0.05 μm. 4 . 4 . The front electrode of an N-type high-efficiency TOPCon battery according to claim 1 , wherein a plurality of PAD solder joints are arranged on the busbar line, and the sizes of each PAD solder joint are different. 5 . 5 . The front electrode of an N-type high-efficiency TOPCon battery according to claim 1 , wherein a break-proof grid is designed at the intersection of the main grid line and the thin grid line. 6 . 6 . The front electrode of an N-type high-efficiency TOPCon battery according to claim 5 , wherein the anti-break grid is designed as a thin grid line, and the intersection of the thin grid line and the main grid line is from the intersection to the distal end. 7 . Tapered to form an isosceles trapezoid. 7 . The front electrode of the N-type high-efficiency TOPCon battery according to claim 1 , wherein the thin grid lines at the connection between the thin grid lines and the PAD solder joints do not penetrate the PAD solder joints. 8 . 8 . The front electrode of the N-type high-efficiency TOPCon battery according to claim 1 , wherein there are annular marking points on the thin grid lines, and corresponding solid graphic marking points on the main grid lines. 9 . 9. The front electrode of the N-type high-efficiency TOPCon battery according to claim 8, characterized in that: there are circular marking points on the thin grid lines, and corresponding solid circular marking points are arranged on the main grid lines, and the circle The diameter of the ring is 0.8um and the diameter of the circle is 0.8um.

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