CN218896643U

CN218896643U - Solar cell, cell sheet and photovoltaic module

Info

Publication number: CN218896643U
Application number: CN202223122081.1U
Authority: CN
Inventors: 周彬; 王豪兵; 衡阳; 潘励刚
Original assignee: Funing Atlas Sunshine Power Technology Co ltd; Atlas Sunshine Power Group Co Ltd
Current assignee: Canadian Solar Inc; Funing Atlas Sunshine Power Technology Co ltd
Priority date: 2022-11-23
Filing date: 2022-11-23
Publication date: 2023-04-21
Anticipated expiration: 2032-11-23

Abstract

The utility model provides a solar cell, a cell and a photovoltaic module, wherein the solar cell comprises a silicon substrate and a back main grid arranged on the back of the silicon substrate, the back main grid comprises two secondary main grids and a plurality of back electrodes arranged between the two secondary main grids at intervals along a first direction, the secondary main grids are provided with a first part and a second part which are connected with each other, the first part and one of the back electrodes are correspondingly arranged along a second direction perpendicular to the first direction, and the distance between the first parts of the two secondary main grids is smaller than the distance between the second parts of the two secondary main grids. The solar cell is adopted by the photovoltaic module, so that the welding performance and quality are more reliable, and the on-site process adjustment and optimization are facilitated.

Description

Solar cell, cell sheet and photovoltaic module

Technical Field

The utility model relates to the technical field of solar power generation, in particular to a solar cell, a cell piece and a photovoltaic module.

Background

Crystalline silicon solar cells and photovoltaic modules still occupy the main position of the global photovoltaic market at present, and the requirements of the market on the photoelectric conversion efficiency of the crystalline silicon solar cells are also higher and higher. The front and back sides of the double-sided solar cell can be subjected to illumination and photoelectric conversion, and compared with the traditional crystalline silicon solar cell, the solar cell can effectively improve the generated energy of a unit irradiation area.

Existing bifacial solar cell back grids typically include an "aluminum frame" made of aluminum paste and a back silver electrode disposed in the "aluminum frame". The obvious height difference exists between the back silver paste and the back aluminum paste in the printing and forming process, so that the obvious height difference is also a main factor causing poor welding of the back silver electrode. It has been disclosed in the art that the back main gate is provided with two sub main gates spaced apart from each other, and a portion of the back sub gate is connected to the two sub main gates at the same time, and the back main gate adjacent to the back silver electrode in the soldering direction forms a silicon leakage region between the two sub main gates. However, when the welding strip is welded to the back of the battery, if the welding strip is deviated in position, the welding strip is easy to abut against the secondary main grid beside the back silver electrode, the welding stability is still affected, and the welding abnormal condition is not easy to be found in time by field personnel.

In view of this, it is necessary to provide a new solar cell, a cell sheet and a photovoltaic module.

Disclosure of Invention

The utility model aims to provide a solar cell, a cell piece and a photovoltaic module, which can improve the back welding performance of the solar cell and facilitate on-site process monitoring and adjustment.

In order to achieve the above-mentioned object, the present utility model provides a solar cell, including a silicon substrate, a back main gate disposed on the back of the silicon substrate, wherein: the back main grid comprises two secondary main grids extending along a first direction and a plurality of back electrodes arranged between the two secondary main grids at intervals along the first direction, the secondary main grids are provided with a first part and a second part which are mutually connected, the first part and one of the back electrodes are correspondingly arranged along a second direction perpendicular to the first direction, and the distance between the first parts of the two secondary main grids is smaller than that between the second parts of the two secondary main grids.

Further, the second portion is arc-shaped.

Further, the number of the back electrodes on the same back main gate is set to 6-15.

Further, the back electrode comprises an edge electrode adjacent to the silicon-based bottom edge along a first direction and an intermediate electrode arranged at intervals with the edge electrode, and at least part of the intermediate electrode extends along the first direction for a distance smaller than the extending distance of the edge electrode along the first direction.

Further, the two secondary main grids are symmetrically arranged along the second direction, the back electrodes are simultaneously connected to the two secondary main grids, and the back electrodes do not exceed the secondary main grids along the second direction; the back electrode is I-shaped, king-shaped or rectangular.

Further, the extending distance d1 of the back electrode along the first direction is not greater than the extending distance d2 of the back electrode along the second direction, and the ratio of the two is 1:1-1:5.

Further, the extension distance d2 of the back electrode along the second direction is set to be 1 mm-3 mm; the overlapping width of the back electrode and the first part is set to be 0.1 mm-0.4 mm.

Further, the width of the secondary main grid is set to be 0.5 mm-1.5 mm; the distance between the two secondary main grids is set to be 0.5-1.5 mm.

Further, the back main grid comprises a main body part and end parts, and the whole width of the end parts gradually increases along the direction towards the main body part.

Further, the solar cell further comprises a back side auxiliary grid extending along the second direction and connected with the back side main grid, the back side auxiliary grid comprises a first auxiliary grid and a second auxiliary grid, the first auxiliary grid is simultaneously connected with two auxiliary main grids of the same back side main grid, and a fracture area is formed between the two auxiliary main grids by the second auxiliary grid.

Further, the tail end of the back main grid is provided with 1-4 second auxiliary grids; the second sub-gate is also provided at least partially beside the back electrode in the first direction.

The utility model also provides a battery piece, which comprises at least two battery areas, wherein the battery piece is divided so that at least one battery area forms any solar battery.

The utility model also provides a photovoltaic module, which comprises a plurality of battery strings, wherein the battery strings are provided with a plurality of any solar batteries, and the plurality of solar batteries are sequentially connected along a first direction.

The beneficial effects of the utility model are as follows: according to the solar cell, the cell and the photovoltaic module, the space between the secondary main grids beside the back electrode is increased through the optimal design of the back main grid, so that the back welding performance of the solar cell is effectively improved; in the welding process of the battery string, even if the welding strip is deflected to a certain extent, the welding strip can be prevented from being abutted with the second part beside the back electrode, so that the welding reliability is affected, and the welding state of the back surface of the solar battery can be better observed by field personnel, so that the process adjustment is convenient.

Drawings

FIG. 1 is a schematic view of a back structure of a battery sheet according to a preferred embodiment of the present utility model;

FIG. 2 is an enlarged view of a portion of area A of FIG. 1;

FIG. 3 is a schematic view of the back electrode structure of the battery plate in FIG. 1;

fig. 4 is a schematic view of a part of the structure of a cell string of the photovoltaic module of the present utility model.

100-cell pieces; 101-a solar cell; 1-a silicon substrate; 11-edge; 2-back main gate; 201-a main body portion; 202-end; 21-secondary main grid; 211-a first part; 212-a second portion; 22-a back electrode; 221-edge electrode; 222-an intermediate electrode; 3-a back side auxiliary grid; 31-a first sub-grid; 32-a second sub-gate; 200-battery strings; 300-welding the strip.

Detailed Description

The present utility model will be described in detail below with reference to embodiments shown in the drawings. The embodiment is not intended to limit the present utility model, and structural, methodological, or functional modifications of the utility model according to the embodiment are included in the scope of the utility model.

Referring to fig. 1, a battery sheet 100 according to the present utility model is shown having two adjacent battery areas. The solar cell 100 is divided into two halves (as shown by a straight line L in fig. 1), so as to obtain two corresponding solar cells 101, where the solar cells 101 are half-sheet type double-sided cells.

Referring to fig. 2 to 4, the solar cell 101 includes a silicon substrate 1, a back main gate 2 disposed on the silicon substrate 1, and a back sub-gate 3 connected to the back main gate 2. The silicon substrate 1 may be a monocrystalline silicon substrate or a polycrystalline silicon substrate, the silicon substrate 1 is substantially rectangular and has two edges 11 arranged along a first direction, the edges 11 being long sides of the half-sheet type double-sided battery; the whole back main grid 2 is arranged in an extending way along the first direction; the back sub-gate 3 is arranged to extend in a second direction perpendicular to the first direction.

The solar cell 101 may be configured as a multi-primary grid cell; each of the back main grids 2 includes two sub main grids 21 extending along a first direction, and a plurality of back electrodes 22 disposed between the two sub main grids 21 and arranged at intervals along the first direction. The back electrode 22 is connected to at least one of the secondary main grids 21, preferably, two secondary main grids 21 are symmetrically arranged along the second direction, and the back electrode 22 is simultaneously connected to two secondary main grids 21 and does not exceed the secondary main grids 21 along the second direction.

The secondary main gate 21 has a first portion 211 and a second portion 212 connected to the first portion 211, the first portion 211 extends along a first direction, and the first portion 211 is disposed corresponding to one of the back electrodes 22 along the second direction, that is, the back electrode 22 is connected to the first portion 211. It is easily understood that one or both sides of the first portion 211 to which the back electrode 22 is connected may be connected to provide the corresponding second portion 212, that is, the second portion 212 may be provided at one or both ends of the corresponding back electrode 22.

With respect to a certain back electrode 22, the first portions 211 of the two secondary main grids 21 are spaced apart from each other by a smaller distance than the second portions 212 of the two secondary main grids 21, in other words, the spacing between the two secondary main grids 21 at positions adjacent to the back electrode 22 is increased, so that the back electrode 22 is less susceptible to the secondary main grids 21 when the subsequent welding is performed. In addition, by arranging the second portion 212 in a protruding manner, the width is increased, so that whether the welding position is accurate or not can be easily identified and observed, and the process adjustment is facilitated. The second portion 212 is smoothly connected to the first portion 211, and the second portion 212 is preferably in a circular arc shape.

The number of the back electrodes 22 on the same back main grid 2 is set to be 6-15, and the slurry consumption of the back electrodes 22 is reduced through a distributed multi-point design. The back electrode 22 includes an edge electrode 221 disposed adjacent to the edge 11 of the silicon substrate 1 along a first direction, and an intermediate electrode 222 disposed at a distance from the edge electrode 221, at least a portion of the intermediate electrode 222 extending in the first direction by a distance smaller than that of the edge electrode 221. The back electrode 22 is preferably configured in an i-shape, a king-shape or a rectangular shape. In practical applications, all the secondary main grids 21 beside the back electrodes 22 may be designed to protrude, that is, the first portion 211 corresponding to each back electrode 22 is connected with the second portion 212 with increased space; the projecting design of the secondary main grid 21 can also be performed only at the side of part of the back electrode 22 according to the actual product requirement.

In this embodiment, the width of the secondary main grid 21 along the second direction is set to be 0.5 mm-1.5 mm; the distance between the two secondary main grids 21 is set to be 0.5 mm-1.5 mm. The extending distance d1 of the back electrode 22 along the first direction is not greater than the extending distance d2 of the back electrode 22 along the second direction, and the ratio of the two is 1:1-1:5. Specifically, the extension distance d2 of the back electrode 22 in the second direction is set to 1mm to 3mm; the overlapping width of the back electrode 22 and the first portion 211 is set to be 0.1mm to 0.4mm.

In terms of the overall structure, the rear main grid 2 includes a main body 201 and end portions 202 connected to both ends of the main body 201. The overall width of the end portion 202 gradually increases in the direction toward the main body portion 201, that is, the edges of the two secondary main grids 21 at the position of the end portion 202 facing away from each other gradually expand in the direction toward the main body portion 201. Specifically, the end portion 202 has a trapezoid shape as a whole, and the pitch of the secondary main grating 21 at the position of the end portion 202 is larger than the pitch of the secondary main grating 21 at the position of at least part of the main body portion 201. By the design, the current collection capability of the back main gate 2 can be improved, and the stress abnormality and hidden crack risk of the silicon substrate 1 at the end 202 position of the back main gate 2 can be reduced.

The solar cell 101 further comprises a back side auxiliary grid 3 extending along the second direction and connected with the back side main grid 2, wherein the back side auxiliary grid 3 and the auxiliary main grid 21 are usually printed by aluminum paste; the back electrode 22 is printed by silver paste or silver-aluminum paste. The thickness of the conductive patterns obtained by printing, drying and sintering different slurries is different, and the thickness of the back electrode 22 is smaller than the thicknesses of the back auxiliary grid 3 and the secondary main grid 21.

The back auxiliary grid 3 comprises a first auxiliary grid 31 and a second auxiliary grid 32, and the first auxiliary grid 31 is connected with two auxiliary main grids 21 of the same back main grid 2 at the same time; the second sub-gate 32 forms a break region between the two sub-main gates 21. Here, the end 202 of the back main gate 2 is provided with 1 to 4 second auxiliary gates 32, so that the end of the back main gate 2 is in an opening shape, and the stress after the subsequent welding at the corresponding position of the silicon substrate 1 is reduced; the second sub-gate 32 is also disposed at least partially beside the back electrode 22 along the first direction, that is, the back sub-gate 3 adjacent to the back electrode 22 is disposed intermittently, so as to reduce the influence on the subsequent soldering process of the back electrode 22.

Of course, the solar cell 101 further includes a front electrode disposed on the front surface of the silicon substrate 1, where the front electrode includes a front main grid (not shown) corresponding to the position of the back main grid 2, which is not described herein again.

Referring to fig. 4, the present utility model further provides a photovoltaic module, which includes a plurality of cell strings 200, wherein the cell strings 200 include a plurality of solar cells 101 sequentially connected along a first direction, and a solder strip 300 connecting adjacent solar cells 101, and the solder strip 300 connects a back main grid 2 of one solar cell 101 with a front main grid of another solar cell 101. The arrangement of the cell strings 200 and the number of the solar cells 101 in each cell string 200 can be designed according to the actual requirements.

The welding strip 300 can be a circular welding strip, and is more suitable for welding a plurality of main grid batteries; the bonding tape may also be a flexible flat bonding tape to reduce edge stress of the silicon substrate 1. In particular, the photovoltaic module may also be configured as a shingle module, and the edges 11 of the cell strings 200 adjacent to the solar cells 101 are formed with overlapping regions, and the overlapping regions may be configured with corresponding conductive layers to electrically connect adjacent solar cells 101. At this time, the solder ribbon 300 may not extend into the overlapping region, that is, the solder ribbon 300 may be connected only to the front-side main grid or the back-side main grid 2 of one of the solar cells 101.

In summary, in the solar cell 101 of the present utility model, the space between the secondary main grids 21 at the side of the back electrode 22 is increased by optimizing the design of the back main grid 2, so that the back soldering performance of the solar cell 101 is effectively improved. In the welding process of the battery string 200, even if the welding strip 300 deflects to a certain extent, interference between the welding strip 300 and the secondary main grid 21 at the side of the back electrode 22 can be effectively avoided, so that cold joint and cold joint are caused, and the product quality is ensured; and the welding state of the back surface of the solar cell 101 can be better observed by field personnel, and the process adjustment is convenient.

It should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is for clarity only, and that the skilled artisan should recognize that the embodiments may be combined as appropriate to form other embodiments that will be understood by those skilled in the art.

The above list of detailed descriptions is only specific to practical embodiments of the present utility model, and they are not intended to limit the scope of the present utility model, and all equivalent embodiments or modifications that do not depart from the spirit of the present utility model should be included in the scope of the present utility model.

Claims

1. The solar cell comprises a silicon substrate and a back main grid arranged on the back of the silicon substrate, and is characterized in that: the back main grid comprises two secondary main grids extending along a first direction and a plurality of back electrodes arranged between the two secondary main grids at intervals along the first direction, the secondary main grids are provided with a first part and a second part which are mutually connected, the first part and one of the back electrodes are correspondingly arranged along a second direction perpendicular to the first direction, and the distance between the first parts of the two secondary main grids is smaller than that between the second parts of the two secondary main grids.

2. The solar cell of claim 1, wherein: the second portion is arc-shaped.

3. The solar cell of claim 1, wherein: the number of the back electrodes on the same back main grid is set to be 6-15.

4. A solar cell according to claim 1 or 3, characterized in that: the back electrode comprises an edge electrode adjacent to the silicon-based bottom edge along a first direction and an intermediate electrode arranged at intervals with the edge electrode, wherein at least part of the intermediate electrode extends less than the edge electrode along the first direction.

5. The solar cell of claim 1, wherein: the two secondary main grids are symmetrically arranged along the second direction, the back electrodes are simultaneously connected to the two secondary main grids, and the back electrodes do not exceed the secondary main grids along the second direction; the back electrode is I-shaped, king-shaped or rectangular.

6. The solar cell of claim 1, wherein: the extending distance d1 of the back electrode along the first direction is not greater than the extending distance d2 of the back electrode along the second direction, and the ratio of the extending distance d1 to the extending distance d2 is 1:1-1:5.

7. The solar cell according to claim 5 or 6, characterized in that: the extension distance d2 of the back electrode along the second direction is set to be 1 mm-3 mm; the overlapping width of the back electrode and the first part is set to be 0.1 mm-0.4 mm.

8. The solar cell of claim 7, wherein: the width of the secondary main grid is set to be 0.5-1.5 mm; the distance between the two secondary main grids is set to be 0.5-1.5 mm.

9. The solar cell of claim 1, wherein: the back main grid comprises a main body part and end parts, and the whole width of the end parts gradually increases along the direction towards the main body part.

10. The solar cell of claim 1, wherein: the solar cell further comprises a back auxiliary grid extending along a second direction and connected with the back main grid, the back auxiliary grid comprises a first auxiliary grid and a second auxiliary grid, the first auxiliary grid is simultaneously connected with two auxiliary main grids of the same back main grid, and a fracture area is formed between the two auxiliary main grids by the second auxiliary grid.

11. The solar cell of claim 10, wherein: 1-4 second auxiliary grids are arranged at the tail end of the back main grid; the second sub-gate is also provided at least partially beside the back electrode in the first direction.

12. A battery sheet comprising at least two battery regions, characterized in that: the cell sheet being divided such that at least one of the cell regions forms a solar cell as claimed in any one of claims 1 to 11.

13. A photovoltaic module, includes a plurality of battery strings, its characterized in that: the battery string has a plurality of solar cells as claimed in any one of claims 1 to 11, the plurality of solar cells being connected in sequence along a first direction.