CN211828804U

CN211828804U - Solar cell, cell piece and photovoltaic module

Info

Publication number: CN211828804U
Application number: CN202020831641.2U
Authority: CN
Inventors: 邓士锋; 夏正月; 许涛; 邢国强
Original assignee: CSI Cells Co Ltd; CSI GCL Solar Manufacturing Yancheng Co Ltd
Current assignee: Funing atlas sunshine Power Technology Co., Ltd; CSI Cells Co Ltd
Priority date: 2020-05-18
Filing date: 2020-05-18
Publication date: 2020-10-30
Anticipated expiration: 2030-05-18

Abstract

The application provides a solar cell, battery piece and photovoltaic module, solar cell includes silicon substrate, sets up the electrode owner bars that silicon substrate surface and edge first direction extend, the end of electrode owner bars is formed with the edge pad, solar cell is still including connecting the edge owner bars of edge pad. According to the photovoltaic module, the electric connection of the adjacent solar cells is realized through the conducting layer, the collection and transmission performance of surface current is enhanced through the confluence piece, the confluence piece does not influence the overlapping of the adjacent solar cells, and the hidden edge cracking risk is reduced; and through the arrangement of the edge bonding pad, the reliable connection of the confluence piece and the quality of the assembly product are ensured.

Description

Solar cell, cell piece and photovoltaic module

Technical Field

The application 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 are still photovoltaic products with the most mature technical development and the most extensive application at present. The solar cell string of the traditional photovoltaic module mainly adopts a welding strip to connect adjacent solar cells in series, and then the power output is realized through a bus bar. The laminated assembly is characterized in that the edges of the adjacent solar cells are overlapped, and the electric connection of the adjacent solar cells is realized by adopting the conductive adhesive, so that the utilization rate of the photovoltaic assembly to the light receiving area is effectively improved; the laminated tile assembly does not need to adopt a solder strip for connecting adjacent solar cells, but still has the problems of high cost, poor reliability and the like.

In recent years, a stitch welding assembly is also provided, the edge positions of adjacent solar cells are overlapped, the utilization rate of a light receiving area is improved, meanwhile, the electrical connection of the adjacent solar cells is realized through a welding strip, the edge position stress of the solar cells in the assembly product is large, and the edge hidden crack is easily caused. Also disclosed in the art is a laminate assembly wherein adjacent solar cells are connected by providing conductive paste in the overlap region and providing solder strips on the surface of the solar cells that do not extend to the overlap region. For a multi-main-grid battery plate, the width of the main grid on the front surface is small, and if the welding strip has the abnormality of position deflection, welding failure and the like, the collection of surface current and the power output of a component product are also seriously influenced.

In view of the above, there is a need for a new solar cell, a new cell sheet and a new photovoltaic module.

SUMMERY OF THE UTILITY MODEL

The application aims to provide a solar cell, a cell piece and a photovoltaic module, which can reduce hidden crack risk, ensure current transmission performance and improve the output power and reliability of a photovoltaic module product.

In order to realize the above application purpose, the present application provides a solar cell, include silicon substrate, set up and be in the electrode main grid that silicon substrate surface just extends along first direction, the end of electrode main grid is formed with the edge pad, solar cell is still including connecting the edge main grid of edge pad.

As a further improvement of the application, the extension length of the edge welding disc along the first direction is set to be 4-8 mm; and the width of the edge bonding pad along a second direction perpendicular to the first direction is set to be 0.4-2 mm.

As the further improvement of this application, the edge pad setting is trapezoidal, the length on the base of edge pad set up to 1.6 ~ 2.0mm and this base with edge main grid meets, the topside of edge pad is kept away from edge main grid and its length set up to 0.8 ~ 1 mm.

As a further improvement of the present application, the edge pads are arranged in a dumbbell shape.

As a further improvement of the application, the electrode main grid is also provided with a plurality of bonding pads which are arranged at intervals along the first direction.

As a further refinement of the present application, any of the pads is smaller than the edge pads.

As a further improvement of the present application, the electrode main grid is set as a front side main grid, and the edge main grid is a front side edge main grid; the solar cell further comprises a back side edge main grid, and the back side edge main grid and the front side edge main grid are respectively arranged close to two opposite side edges of the silicon substrate along the first direction.

The application also provides a cell piece, which comprises at least two cell regions, wherein the cell piece is divided so that at least one cell region forms the solar cell.

The application also provides a photovoltaic module, which comprises a plurality of cell strings, wherein the cell strings are provided with a plurality of solar cells which are sequentially overlapped along a first direction and a conducting layer which is arranged in an overlapping area adjacent to the solar cells, each solar cell comprises a plurality of electrode main grids which are extended along the first direction, an edge pad is formed at the tail end of each electrode main grid, and each edge pad extends into the overlapping area; the battery string further comprises a bus bar connected to the electrode main grid and spaced apart from the overlap region.

As a further improvement of the present application, one end of the bus bar is connected to the edge pad.

As a further improvement of the application, the electrode main grid is also provided with a plurality of bonding pads which are arranged at intervals along the first direction, and any bonding pad is smaller than the edge bonding pad.

As a further improvement of the present application, the solar cell further comprises a front edge main grid and a back edge main grid; the conducting layer is arranged between the front side edge main grid of one solar cell and the back side edge main grid of the other solar cell.

As a further improvement of the present application, the electrode main grid is configured as a front main grid, and the bus bar is a front bus bar connected to the front main grid; the solar cell further comprises a plurality of back surface main grids extending along the first direction, and the cell string further comprises a back surface bus bar connected to the back surface main grids.

As a further improvement of the present application, the conductive layer does not extend beyond the overlapping area of the respective two solar cells.

The beneficial effect of this application is: this application solar cell improves through setting up marginal pad at the one end that the edge main grid is connected to the electrode main grid the current transmission performance of electrode main grid and edge main grid junction, and the structure is more pleasing to the eye.

The confluence piece and the conducting layer of the photovoltaic module are mutually independent and arranged, and the conducting layer is used for realizing the electric connection of adjacent solar cells and enhancing the current collection and transmission performance of the surface of the solar cell. The confluence piece does not influence the overlapping of the solar cells, the hidden edge cracking risk of the solar cells is reduced, the edge bonding pad can prevent the confluence piece from being close to the tail end of the edge main grid to deflect and be detached, the reliable connection of the confluence piece and the electrode main grid is effectively ensured, and the product quality is improved.

Drawings

Fig. 1 is a schematic front view of a preferred embodiment of a battery cell of the present application;

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

FIG. 3 is a schematic diagram of a back side structure of the battery cell shown in FIG. 1;

FIG. 4 is a schematic diagram of a process for preparing a back electrode of the cell of FIG. 3;

FIG. 5 is a schematic front view of another preferred embodiment of a battery cell of the present application;

FIG. 6 is a partial enlarged view of the area B in FIG. 5;

FIG. 7 is a schematic view of a portion of a photovoltaic module according to the present application;

fig. 8 is a schematic view of a connection structure of adjacent solar cells of the cell string in the photovoltaic module of fig. 7.

100-a battery piece; 101-a solar cell; 1-a silicon substrate; 21-front main grid; 211-edge pads; 212-a pad; 212 a-first pad; 212 b-second pad; 22-front edge main grid; 23-front side sub-grid; 31-back side main gate; 311-sub-electrodes; 312-a frame-like portion; 313-a connecting portion; 32-back edge main gate; 33-back side sub-gate; 200-a battery string; 201-an overlap region; 202-a conductive layer; 203-front side bus bar; 204 — back side bus bar.

Detailed Description

The present application will be described in detail below with reference to embodiments shown in the drawings. The present invention is not limited to the above embodiments, and structural, methodological, or functional changes made by one of ordinary skill in the art according to the present embodiments are included in the scope of the present invention.

Referring to fig. 1, a battery sheet 100 having two adjacent battery regions is provided. The cell sheet 100 is divided into two halves (as shown by the dotted lines in fig. 1), so as to obtain two corresponding solar cells 101, wherein the solar cells 101 are half-sheet cells.

As shown in fig. 2 to 4, the solar cell 101 includes a silicon substrate 1, electrode main grids disposed on a surface of the silicon substrate 1 and extending along a first direction, and edge main grids extending along a second direction perpendicular to the first direction. Specifically, the front surface and the back surface of the silicon substrate 1 are respectively provided with a front electrode and a back electrode. The front electrode comprises a plurality of front main grids 21 extending along a first direction, front edge main grids 22 extending along a second direction perpendicular to the first direction, and front auxiliary grids 23 extending along the second direction and connected with the front main grids 21; the back electrode comprises a plurality of back main grids 31 extending along a first direction and back edge main grids 32 extending along a second direction. Here, the solar cell 101 is provided as a bifacial cell, and the back electrode further includes a back sub-grid 33 extending in the second direction.

Typically, for a P-type cell, the front electrode is provided as a silver electrode; the back electrode is generally formed by printing a back silver paste (shown in fig. 4) on the back surface of the silicon substrate 1, drying, printing a corresponding silver-aluminum paste, and sintering. The back surface main grid 31 comprises a plurality of sub-electrodes 311 arranged at intervals along a first direction, frame-shaped parts 312 surrounding the sub-electrodes 311 and at least partially overlapping and connecting with the sub-electrodes 311, and connecting parts 313 connected to the back surface edge main grid 32, wherein the width of the connecting parts 313 is gradually increased in a direction approaching the back surface edge main grid 32. The sub-electrode 311 is a silver electrode obtained by sintering the back silver paste; the frame-shaped portion 312 and the connecting portion 313 are obtained by sintering the silver-aluminum paste. Of course, the sub-electrode 311 can also be directly connected to the back edge main gate 32, which is not described in detail herein.

The silicon substrate 1 is substantially rectangular and has two parallel side edges 11 disposed opposite to each other along a first direction, and the side edges 11 are long edges of the silicon substrate 1. The front-side edge main grid 22 and the back-side edge main grid 32 are respectively arranged adjacent to the two side edges 11 of the silicon substrate 1. For the aforementioned cell 100, the front edge main grid 22 is disposed adjacent to the edge of the cell 100; the two back edge main grids 32 are arranged in the middle of the battery piece 100. In this embodiment, the back edge main grids 32 of the two solar cells 101 can be obtained by dividing the same electrode grid line printed on the cell 100. In order to save the consumption of the slurry, two electrode grid lines can be printed on two sides of the to-be-divided line of the battery piece 100.

An edge bonding pad 211 connected to the front edge main grid 22 is formed at one end of the front edge main grid 21 facing the front edge main grid 22, and the edge bonding pad 211 can improve the current transmission performance at the connection position of the front edge main grid 22 and the front edge main grid 21. Preferably, the extension length of the edge pad 211 along the first direction is set to be 4-8 mm; and the width of the edge bonding pad 211 along the second direction is set to be 0.4-2 mm.

In this embodiment, the edge pad 211 is trapezoidal, the length of the bottom side of the edge pad 211 is set to be 1.6-2.0 mm, and the bottom side is connected to the front edge main gate 22, and the top side of the edge pad 211 is far away from the front edge main gate 22 and the length of the top side is set to be 0.8-1 mm. Referring to fig. 5 and 6, the edge pads 211 are disposed in a dumbbell shape. The function of the edge pads 211 in the assembly product will also be described in further detail below.

The front main grid 21 further has a plurality of pads 212 arranged at intervals along a first direction, and any pad 212 is smaller than the edge pad 211; the front main grid 21 is branched at one end far away from the edge bonding pad 211. The bonding pad 212 includes a first bonding pad 212a disposed in a middle region of the front-side main grid 21, and a second bonding pad 212b located at an end of the front-side main grid 21 away from the edge bonding pad 211, and a width of the first bonding pad 212a along a second direction is smaller than a width of the second bonding pad 212b along the second direction. It should be noted that, here, the first pad 212a is not limited to be disposed at the midpoint of the front side main grid 21, and other pads are further disposed between the first pad 212a and the second pad 212b and between the first pad 212a and the edge pad 211, and as a whole, the width of the pad 212 disposed on the front side main grid 21 gradually increases from the middle region of the front side main grid 21 to both ends.

Besides, in order to reduce the slurry consumption, the front-side edge main grid 22 and the back-side edge main grid 32 may be provided with a segmented structure, which may be designed according to the solar cell 101 and the corresponding module product requirements.

Referring to fig. 7, the photovoltaic module provided by the present application includes a plurality of cell strings 200, where the cell strings 200 include a plurality of solar cells 101 sequentially arranged in an overlapping manner along a first direction, and the arrangement manner of the cell strings 200 and the number of the solar cells 101 in each cell string 200 may be designed according to actual requirements.

As shown in fig. 8, the cell string 200 further includes a conductive layer 202 disposed in the overlapping region 201 adjacent to the solar cell 101, a front bus bar 203 connected to the front main grid 21 of the solar cell 101, and a back bus bar 204 connected to the back main grid 31. The width of the overlapping area 201 is set to be 1-1.4 mm, and the adjacent connection reliability of the solar cell 101 and the loss of the light receiving area of the cell are considered. The conductive layer 202 may be provided as a conductive adhesive; the front bus bar 203 and the back bus bar 204 may be circular solder strips. In other embodiments of the present application, the conductive layer 202 may also be a flexible flat solder strip, solder paste, or metal solder.

Wherein the conductive layer 202 is disposed between the front edge main grid 22 of one of the solar cells 101 and the back edge main grid 32 of the other solar cell 101. Preferably, the conductive layer 202 does not exceed the overlapping region 201 of the two corresponding solar cells 101, so as to avoid affecting the light receiving area of the solar cells 101.

The adjacent solar cells 101 are electrically connected through the conductive layer 202, and the front surface bus bar 203 and the back surface bus bar 204 enhance the collection and transmission performance of the surface current. One end of the front surface bus bar 203 facing the front surface edge main grid 22 is connected to the edge pad 211 and is arranged at an interval with the overlapping region 201, in other words, the front surface bus bar 203 does not extend into the overlapping region 201, so that the edge stress of the solar cell 101 is reduced, and the hidden crack risk is greatly reduced. Likewise, the back bus bar 204 also does not extend into the overlap region 201.

During the preparation of the battery string 200, due to the small width of the front main grid 21, the end of the front bus bar 203, i.e. the position close to the front edge main grid 22, may be deflected and welded, which greatly affects the current collecting and transmitting function of the front bus bar 203 and the overall appearance of the assembly product. The edge bonding pad 211 not only realizes the reliable connection between the front main grid 21 and the front edge main grid 22, but also the tail end of the front bus bar 203 facing the front edge main grid 22 can be firmly welded and fixed on the edge bonding pad 211, thereby ensuring the reliable connection and the integral aesthetic property of the adjacent solar cells 101. In addition, the pads 212 spaced on the front main grid 21 also serve to ensure reliable soldering and fixing of the front bus bar 203.

To sum up, this application solar cell 101 sets up edge pad 211 through the one end of connecting positive edge main grid 22 at positive main grid 21, improves the current transmission performance of positive main grid 21 and the positive edge main grid 22 junction, and the structure is more pleasing to the eye. This application photovoltaic module adopts above-mentioned solar cell 101 to make corresponding battery cluster 200, only passes through conducting layer 202 realizes adjacent solar cell 101's electric connection, when the current collection on front confluence piece 203 reinforcing surface and transmission performance, do not influence solar cell's overlap, reduce the latent risk of splitting in edge. The edge bonding pad 211 can also effectively prevent the tail end of the front surface bus piece 203 adjacent to the front surface edge main grid 22 from deflecting and desoldering, ensure the reliable connection between the front surface bus piece 203 and the front surface main grid 21, and improve the product quality.

It should be understood that although the present description refers to embodiments, not every embodiment contains only a single technical solution, and such description is for clarity only, and those skilled in the art should make the description as a whole, and the technical solutions in the embodiments can also be combined appropriately to form other embodiments understood by those skilled in the art.

The above list of details is only for the concrete description of the feasible embodiments of the present application, they are not intended to limit the scope of the present application, and all equivalent embodiments or modifications that do not depart from the technical spirit of the present application are intended to be included within the scope of the present application.

Claims

1. A solar cell comprises a silicon substrate, and an electrode main grid arranged on the surface of the silicon substrate and extending along a first direction, and is characterized in that: the end of the electrode main grid is provided with an edge bonding pad, and the solar cell further comprises an edge main grid connected with the edge bonding pad.

2. The solar cell of claim 1, wherein: the extension length of the edge welding disc along the first direction is set to be 4-8 mm; and the width of the edge bonding pad along a second direction perpendicular to the first direction is set to be 0.4-2 mm.

3. The solar cell of claim 1, wherein: the edge bonding pad is trapezoidal, the length of the bottom edge of the edge bonding pad is set to be 1.6-2.0 mm, the bottom edge of the edge bonding pad is connected with the edge main grid, the top edge of the edge bonding pad is far away from the edge main grid, and the length of the top edge of the edge bonding pad is set to be 0.8-1 mm.

4. The solar cell of claim 1, wherein: the edge bonding pad is arranged in a dumbbell shape.

5. The solar cell of claim 1, wherein: the electrode main grid is also provided with a plurality of bonding pads which are arranged at intervals along the first direction.

6. The solar cell of claim 5, wherein: any of the pads is smaller than the edge pads.

7. The solar cell of claim 1, wherein: the electrode main grid is a front main grid, and the edge main grid is a front edge main grid; the solar cell further comprises a back side edge main grid, and the back side edge main grid and the front side edge main grid are respectively arranged close to two opposite side edges of the silicon substrate along the first direction.

8. A battery piece comprising at least two battery regions, characterized in that: the cell sheet is divided such that at least one of the cell regions forms a solar cell according to any of claims 1-7.

9. The utility model provides a photovoltaic module, includes a plurality of battery clusters, the battery cluster has along a plurality of solar cell that first direction overlaps in proper order, sets up adjacently the conducting layer in solar cell's the overlap region, its characterized in that: the solar cell comprises a plurality of electrode main grids extending along a first direction, wherein edge pads are formed at the tail ends of the electrode main grids and extend into the overlapping area; the battery string further comprises a bus bar connected to the electrode main grid and spaced apart from the overlap region.

10. The photovoltaic module of claim 9, wherein: one end of the bus bar is connected to the edge pad.

11. The photovoltaic module of claim 9, wherein: the extension length of the edge welding disc along the first direction is set to be 4-8 mm; and the width of the edge bonding pad along a second direction perpendicular to the first direction is set to be 0.4-2 mm.

12. The photovoltaic module of claim 9, wherein: the electrode main grid is also provided with a plurality of bonding pads which are arranged at intervals along the first direction, and any bonding pad is smaller than the edge bonding pad.

13. The photovoltaic module of claim 9, wherein: the solar cell also comprises a front edge main grid and a back edge main grid; the conducting layer is arranged between the front side edge main grid of one solar cell and the back side edge main grid of the other solar cell.

14. The photovoltaic module of claim 9, wherein: the electrode main grid is arranged as a front main grid, and the confluence piece is a front confluence piece connected to the front main grid; the solar cell further comprises a plurality of back surface main grids extending along the first direction, and the cell string further comprises a back surface bus bar connected to the back surface main grids.

15. The photovoltaic module of claim 9, wherein: the conductive layer does not exceed the overlapping area of the two corresponding solar cells.