Electrode structure of back contact battery

Abstract

The invention discloses an electrode structure of a back contact battery. The electrode structure comprises first fine grids, second fine grids, pad points and main grids, the first fine grids and the second fine grids are mutually staggered and arranged in parallel; the first fine grids and the second fine grids are vertically crossed with the main grids; the intersection of the second fine grid and the main grid is disconnected; the rest of the main grids except the main grid on the outermost side are divided into a plurality of first main grid segments by the first fine grids; the two sides of the first main grid subsection are arc-shaped, so that the first main grid subsection forms an hourglass-shaped structure; and the pad point stretches across at least two second fine grids. According to the invention, the main grid in the middle area of the electrode structure is divided into a plurality of first main grid segments through the first fine grids, and each main grid segment is set as a hourglass-shaped structure, so that the current conducted from the fine grids is transmitted to the main grid along an arc line, and the transmission path is shorter than the right-angle transmission path, thereby effectively reducing the series resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and more particularly to an electrode structure of a back-contact battery. Background Art

[0002] For the metallization of solar cells, how to reduce shading and lower the series resistance has always been a question worth considering. In the BC (back contact) structure, the metallized electrodes are placed on the back without considering shading losses. However, due to the unique cell structure of BC, some fine grids are usually disconnected at the main grid, which undoubtedly increases the series resistance. Therefore, how to optimize the current transmission path is crucial to reducing the series resistance of BC cells.

[0003] Therefore, how to provide an electrode structure of a back-contact battery that can reduce series resistance is one of the technical problems that urgently need to be solved in this field. Summary of the invention

[0004] In view of this, the present invention provides an electrode structure of a back-contact battery, the purpose of which is to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] An electrode structure of a back-contact battery comprises: a first fine grid, a second fine grid, a pad point and a main grid; the first fine grid and the second fine grid are staggered and arranged in parallel with each other; the first fine grid and the second fine grid are arranged perpendicularly to the main grid; the second fine grid is disconnected at the intersection with the main grid; the first fine grid divides the remaining main grids except the outermost main grid into a plurality of first main grid segments; the two sides of the first main grid segment are set to be arc-shaped, so that the first main grid segment forms an hourglass-shaped structure; the pad point spans at least two of the second fine grids.

[0007] Preferably, the middle width of the first main grid segment is 0.05-0.2 mm.

[0008] Preferably, when the ends of the second fine gates on both sides of the pad point are in an H-shaped structure, a side of the end of the second fine gate away from the pad point is set to be in an arc shape.

[0009] Preferably, the first fine grid divides the outermost main grid into a plurality of second main grid segments; the inner sides of the second main grid segments are set to be arc-shaped.

[0010] Preferably, when the ends of the second fine grid on both sides of the pad point are in an I-shaped structure, both sides of the ends of the second fine grid are set to be arc-shaped.

[0011] Preferably, the first fine grid divides the outermost main grid into a plurality of third main grid segments; the inner sides of the third main grid segments are set to be arc-shaped.

[0012] Preferably, when the ends of the second fine gates on both sides of the pad point are in a barb-shaped structure, a side of the end of the second fine gate close to the pad point is set to be an arc shape.

[0013] Preferably, the first fine grid divides the outermost main grid into a plurality of fourth main grid segments; the inner sides of the fourth main grid segments are set to be arc-shaped.

[0014] Compared with the prior art, the present invention achieves the following technical effects: the present invention divides the main grid in the middle area of ​​the electrode structure into multiple first main grid segments through the first fine grid, and sets each main grid segment into an hourglass-shaped structure, so that arc transmission can be used instead of right-angle transmission, shortening the transmission path of the fine grid current collected by the pad point, thereby reducing the series resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the middle region of an electrode structure of a back contact battery;

[0016] Figure 2 is a schematic diagram when the end of the second fine gate is an H-shaped structure;

[0017] Figure 3 is a schematic diagram when the end of the second fine grid is an I-shaped structure;

[0018] Figure 4 is a schematic diagram of a case where the end of the second fine grid is a barbed hook structure;

[0019] In the figure: 1. First fine grid; 2. Second fine grid; 3. Pad point; 4. Main grid. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0021] In the middle area of ​​the traditional electrode structure, in order to prevent leakage, the second fine grid is usually disconnected at the main grid and the pad point. In order to reduce the resistivity of the main grid line as much as possible, the width of the main grid is usually between 0.1-0.2mm; considering the leakage problem caused by process accuracy and the existence of the Gap area between the main fine grid, the safety distance between the anisotropic fine grids on both sides and the busbar is usually set to about 0.4mm. During use, the current collected by the fine grid first reaches the overlap of the main fine grid along the fine grid, and then is transmitted to the pad point along the main grid. Since the overlap of the main fine grid is designed as a straight line and the angle is 90°, it is "right-angle transmission", which has the problem of large series resistance.

[0022] Embodiment 1

[0023] Reference Figure 1-2 As shown, the present invention discloses an electrode structure of a back-contact battery, comprising: a first fine grid 1, a second fine grid 2, a pad point 3 and a main grid 4; the first fine grid 1 and the second fine grid 2 are staggered and arranged in parallel; the first fine grid 1 and the second fine grid 2 have opposite polarities; the first fine grid 1 and the second fine grid 2 are both arranged perpendicularly to the main grid 4; the second fine grid 2 is disconnected at the intersection with the main grid 4; the first fine grid 1 divides the remaining main grids 4 except the outermost main grid 4 into a plurality of first main grid segments; the two sides of the first main grid segment are set to be arc-shaped, so that the first main grid segment forms an hourglass-shaped structure; the center of the arc-shaped side surface of the first main grid segment is located on the center line of the corresponding second fine grid 2; the pad point 3 spans at least two second fine grids 2.

[0024] The above technical solution divides the main grid in the middle area of ​​the electrode structure into multiple first main grid segments through the first fine grid, and sets each main grid segment to an hourglass-shaped structure, so that the current conducted by the fine grid will be transmitted to the main grid along an arc. The transmission path is shorter than the right-angle transmission, thereby effectively reducing the series resistance. With the upgrade of the back-contact solar cell process and the increase in the number of fine grids, the benefit of reducing the series resistance will be more obvious.

[0025] In this embodiment, the middle width of the first main gate segment is 0.05-0.2mm; specifically, the middle width of the first main gate segment is 0.05mm. By narrowing the middle of the first main gate segment to 0.05mm, a larger space can be provided for the safety distance between the second fine gate 2 and the main gate 4, so that the second fine gate 2 can be further extended toward the main gate 4 by about 0.075mm. This can further reduce the series resistance while ensuring a sufficient safety distance between the second fine gate 2 and the main gate 4.

[0026] In this embodiment, the ends of the second fine gate 2 on both sides of the pad point 3 are H-shaped structures, and the side of the end of the second fine gate 2 away from the pad point 3 is set to be an arc shape, which can reduce the length of the current transmission path at the end of the second fine gate 2, thereby achieving the effect of reducing the series resistance.

[0027] In this embodiment, the first fine grid 1 divides the outermost main grid 4 into a plurality of second main grid segments; the inner side of the second main grid segment is set to be arc-shaped; the center of the arc-shaped side surface of the second main grid segment is located on the center line of the corresponding second fine grid 2.

[0028] Embodiment 2

[0029] Reference Figure 3 As shown, the difference between this embodiment and the first embodiment is that the ends of the second fine gate 2 on both sides of the pad point 3 are I-shaped structures, and the two sides of the end of the second fine gate 2 are set to be arc-shaped, which can reduce the length of the current transmission path at the end of the second fine gate 2, thereby achieving the effect of reducing the series resistance.

[0030] In this embodiment, the first fine grid 1 divides the outermost main grid 4 into a plurality of third main grid segments; the inner side of the third main grid segment is set to be arc-shaped; the center of the arc-shaped side surface of the third main grid segment is located on the center line of the corresponding second fine grid 2.

[0031] Embodiment 3

[0032] Reference Figure 4 As shown, the difference between this embodiment and the first embodiment is that the ends of the second fine gate 2 on both sides of the pad point 3 are inverted hook structures, and the side of the end of the second fine gate 2 close to the pad point 3 is set to be an arc shape, which can reduce the length of the current transmission path at the end of the second fine gate 2, thereby achieving the effect of reducing the series resistance.

[0033] In this embodiment, the first fine grid 1 divides the outermost main grid 4 into a plurality of fourth main grid segments; the inner side of the fourth main grid segment is set to be arc-shaped; the center of the arc-shaped side surface of the fourth main grid segment is located on the center line of the corresponding first fine grid 1.

[0034] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An electrode structure of a back contact battery, characterized in that: include: A first fine grid (1), a second fine grid (2), a pad point (3) and a main grid (4); the first fine grid (1) and the second fine grid (2) are mutually staggered and arranged in parallel; the first fine grid (1) and the second fine grid (2) are arranged perpendicularly and crosswise with the main grid (4); the second fine grid (2) is arranged disconnected at the intersection with the main grid (4); the first fine grid (1) divides the main grid (4) except the outermost main grid (4) into a plurality of first main grid segments; both sides of the first main grid segment are arranged in arc shape; the pad point (3) spans at least two of the second fine grids (2).

2. The electrode structure of a back contact battery according to claim 1, characterized in that: The middle width of the first main grid segment is 0.05-0.2 mm.

3. The electrode structure of a back contact battery according to claim 1, characterized in that: When the ends of the second fine grid (2) on both sides of the pad point (3) are in an H-shaped structure, the side of the end of the second fine grid (2) away from the pad point (3) is set to be in an arc shape.

4. The electrode structure of a back contact battery according to claim 3, characterized in that: The first fine grid (1) divides the outermost main grid (4) into a plurality of second main grid segments; the inner sides of the second main grid segments are set in an arc shape.

5. The electrode structure of a back contact battery according to claim 1, characterized in that: When the ends of the second fine grid (2) on both sides of the pad point (3) are in an I-shaped structure, both sides of the ends of the second fine grid (2) are set to be arc-shaped.

6. The electrode structure of a back contact battery according to claim 5, characterized in that: The first fine grid (1) divides the outermost main grid (4) into a plurality of third main grid segments; the inner sides of the third main grid segments are set in an arc shape.

7. The electrode structure of a back contact battery according to claim 1, characterized in that: When the ends of the second fine grid (2) on both sides of the pad point (3) are in a barbed hook structure, the side of the end of the second fine grid (2) close to the pad point (3) is set to be an arc shape.

8. The electrode structure of a back contact battery according to claim 6, characterized in that: The first fine grid (1) divides the outermost main grid (4) into a plurality of fourth main grid segments; the inner sides of the fourth main grid segments are set in an arc shape.

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