Multi-slice back contact solar cell and photovoltaic module

Abstract

The utility model discloses a multi-fragmentation back contact solar cell and a photovoltaic assembly, comprising a main cell sheet, the main cell sheet comprises a plurality of first cell sheets and a plurality of second cell sheets, the plurality of first cell sheets and the plurality of second cell sheets are arranged in a staggered manner, and fragmentation gaps are arranged between the first cell sheets and the second cell sheets. According to the utility model, the main cell piece can be divided into N + 1 first cell pieces and N + 1 second cell pieces through the N fragmentation gaps, so that the short-circuit current of the divided unit cell pieces is 1 / n of that of the original back-junction back-contact solar cell, the short-circuit current is greatly reduced compared with that of the original two-fragmentation solar cell, and the service life of the cell piece is prolonged. Therefore, the hot spot effect and the hot spot reliability risk of the assembly can be obviously improved, meanwhile, after the unit solar cell is welded, the length of the unit solar cell in the welding strip direction is obviously reduced compared with that of an original two-piece solar cell, and therefore the bending degree of the welded unit solar cell can be relieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to photovoltaic cell field especially relates to a kind of multi-slice back contact solar cell and photovoltaic module. BACKGROUND

[0002] Back contact solar cell with its high conversion efficiency, the beautiful design of no obstruction on front, occupies a place in crystalline silicon solar cell market.This battery's positive and negative electrode cross arrangement is on back, so that front is completely no obstruction, so compared with front junction bifacial solar cell, its short-circuit current can be about 3%-5% higher.Especially using electrode contact passivated N-type back contact solar cell, benefiting from the high bulk carrier lifetime of N-type silicon wafer material and good interface passivation effect, it has become the highest short-circuit current density crystalline silicon solar cell at present.However, due to its structural characteristics and high short-circuit current characteristics, photovoltaic module packaged by back contact solar cell is more susceptible to the influence of hot spot effect, especially when the module is partially shaded, the shaded part can appear temperature too high, and even photovoltaic module can be burned out in serious case.

[0003] The existing back contact solar cell technology has obvious defects, first, due to the cross arrangement of positive and negative electrode on the back of the cell and small spacing, plus larger short-circuit current, the hot spot reliability of the packaged photovoltaic module is poor, and it is easily affected by hot spot effect, and the entire module can be damaged in serious case.Secondly, with the continuous increase of solar cell size, the hot spot risk of back contact module is also higher and higher.In addition, after the back contact solar cell is welded with solder strip, due to the difference of thermal stress, the cell will appear bending phenomenon, and the larger the size, the more obvious the bending.This not only affects the appearance of the cell, but also can adversely affect the performance and life of the cell. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a kind of multi-slice back contact solar cell and photovoltaic module to solve the above insufficient in prior art.

[0005] To achieve the above object, the utility model adopts the following technical scheme: a kind of multi-slice back contact solar cell, including main cell piece, the main cell piece includes multiple first cell piece and second cell piece, multiple the first cell piece and second cell piece are staggered, and the first cell piece and second cell piece are all provided with slice gap between them.And the photovoltaic module made by the above multiple first and second cell piece staggered.

[0006] As a further description of the above technical solutions: the first cell piece and the second cell piece each include an N-type electrode main grid, an N-type electrode fine grid, a P-type electrode main grid, and a P-type electrode fine grid, positions of the N-type electrode main grid and the N-type electrode fine grid of the second cell piece are inversed with positions of the P-type electrode main grid and the P-type electrode fine grid of the first cell piece, and positions of the P-type electrode main grid and the P-type electrode fine grid of the second cell piece are inversed with positions of the N-type electrode main grid and the N-type electrode fine grid of the first cell piece.

[0007] As a further description of the above technical solutions: the number of the slice gaps is set to be 2-7.

[0008] As a further description of the above technical solutions: the width of the slice gap is set to be 0.5-1.5 mm.

[0009] A multi-slice back contact photovoltaic module includes a plurality of multi-slice back contact solar cells.

[0010] As a further description of the above technical solutions: a plurality of solder strips are connected between the first cell pieces and the second cell pieces, and the N-type electrode main grids and the P-type electrode main grids on the first cell pieces and the second cell pieces are sequentially connected by soldering.

[0011] The utility model provides a kind of multi-slice back contact solar cell and photovoltaic module.It has the following beneficial effects: N slice gaps can be separated into N+1 first cell piece and second cell piece by main cell piece, so the unit cell piece is divided out, short-circuit current is 1 / n of original back junction back contact solar cell, short-circuit current is substantially reduced compared to original two slice solar cell, and the hot spot effect and hot spot reliability risk of module can be obviously improved, and simultaneously, the length of unit solar cell along solder strip direction after welding is also obviously reduced compared to original two slice solar cell, so that the bending degree of unit solar cell after welding can be relieved, at this time, silicon wafer below 140um in thickness, for example, 130um thick N-type silicon wafer, is used, which helps to reduce the raw material cost of back junction back contact solar cell.

[0012] It should be understood that the foregoing general description and the following detailed description are merely exemplary and explanatory, and are not intended to limit the present disclosure.

[0013] The present application provides an overview of various implementations or examples of the technology described in the present disclosure, and is not a comprehensive disclosure of the full scope or all features of the disclosed technology. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 A multi-slice back contact solar cell structure schematic diagram is provided for the utility model;

[0015] Figure 2 For the utility model Figure 1 The enlarged structural schematic view of A place of the utility model is shown in the figure.

[0016] Figure 3 The partial three-dimensional structural schematic view of the multi-sliced back contact photovoltaic module of the utility model is shown in the figure.

[0017] Figure 4 The partial cross-sectional schematic view of the multi-sliced back contact photovoltaic module of the utility model is shown in the figure.

[0018] Figure 5 The structural schematic view of the utility model is shown in the figure, in which the various cell slices are connected through solder strips.

[0019] Legend:

[0020] 1, first cell slice; 2, second cell slice; 3, solder strip; 4, slicing gap; 5, filling adhesive film; 6, N-type electrode main grid; 7, P-type electrode main grid; 8, N-type electrode fine grid; 9, P-type electrode fine grid. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only a part of the embodiments of the utility model, rather than all the embodiments.

[0022] Referring to Figures 1-5 A multi-sliced back contact solar cell includes a main cell slice, the main cell slice includes a plurality of first cell slices 1 and second cell slices 2, the plurality of first cell slices 1 and second cell slices 2 are staggered, and a slicing gap 4 is arranged between the first cell slice 1 and the second cell slice 2. The main cell slice can be divided into N+1 first cell slices 1 and second cell slices 2 through N slicing gaps 4. The short-circuit current of the divided unit cell slice is 1 / n of the original back junction back contact solar cell. The short-circuit current is significantly reduced compared with the original two-sliced solar cell, and the hot spot effect and hot spot reliability risk of the module can be obviously improved. At the same time, the length of the unit solar cell along the direction of the solder strip 3 after welding is also obviously reduced compared with the original two-sliced solar cell. In this way, the bending degree of the welded unit solar cell can be relieved. At this time, a silicon wafer with a thickness of less than 140 um, for example, an N-type silicon wafer with a thickness of 130 um, can be used, which helps to reduce the raw material cost of the back junction back contact solar cell.

[0023] As a preferred technical scheme of the embodiment, the first cell piece 1 and the second cell piece 2 each include N-type electrode main grids 6, N-type electrode fine grids 8, P-type electrode main grids 7 and P-type electrode fine grids 9, the positions of the N-type electrode main grids 6 and the N-type electrode fine grids 8 of the second cell piece 2 and the positions of the P-type electrode main grids 7 and the P-type electrode fine grids 9 of the first cell piece 1 are inversed, and the positions of the P-type electrode main grids 7 and the P-type electrode fine grids 9 of the second cell piece 2 and the positions of the N-type electrode main grids 6 and the N-type electrode fine grids 8 of the first cell piece 1 are inversed; the difference between the first cell piece 1 and the second cell piece 2 is that the positions of the N-type grid lines and the P-type grid lines are changed so that the positive and negative electrode positions of the first cell piece 1 and the second cell piece 2 are inversed, thereby facilitating corresponding welding of the positive and negative electrodes of the first cell piece 1 and the second cell piece 2.

[0024] As a preferred technical scheme of the embodiment, a plurality of solder strips 3 are connected between the first cell piece 1 and the second cell piece 2, and the N-type electrode main grids 6 and the P-type electrode main grids 7 on the first cell piece 1 and the second cell piece 2 are sequentially connected by welding through the solder strips 3; the main grids on the plurality of cell pieces can be welded through the solder strips 3, so that the plurality of cell pieces are welded into one whole piece.

[0025] As a preferred technical scheme of the embodiment, a filling adhesive film 5 is arranged on each of the cell piece gaps 4, and the filling adhesive film 5 is arranged at the top end of the solder strip 3; in the process of packaging the cell piece, the processing temperature is high in the lamination step, the adhesive film placed on the cell piece softens and flows, and is filled into the gap; the material of the filling adhesive film 5 is mainly composed of Al Ox / SiNx, SiOx / SiNx and phosphorus-doped SiOx / SiNx, and has the functions of insulation and moisture isolation.

[0026] As a preferred technical scheme of the embodiment, the number of the cell piece gaps 4 is set to be 2-7.

[0027] As a preferred technical scheme of the embodiment, the width of the cell piece gap 4 is set to be 0.5-1.2 mm.

[0028] A multi-piece back contact photovoltaic module includes a plurality of multi-piece back contact solar cells.

[0029] The above merely describes a preferred specific implementation of the present application, but the protection scope of the present application is not limited to this. Any skilled person in the art, according to the technical scheme and the inventive concept of the present application, can make equivalent replacement or change within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A multi-segment back-contact solar cell, comprising a main cell, characterized in that, The main battery cell includes multiple first battery cells (1) and second battery cells (2), which are arranged alternately. A slab gap (4) is provided between each of the first battery cells (1) and the second battery cells (2). Each of the first battery cells (1) and the second battery cells (2) includes an N-type electrode main grid (6), an N-type electrode fine grid (8), a P-type electrode main grid (7), and a P-type electrode fine grid (9). The positions of the N-type electrode main grid (6) and the N-type electrode fine grid (8) of the second battery cell (2) are the same as the positions of the P-type electrode main grid (7) and the P-type electrode fine grid (9) of the first battery cell (1). The positions of the P-type electrode main grid (7) and P-type electrode fine grid (9) of the second battery cell (2) are swapped with the positions of the N-type electrode main grid (6) and N-type electrode fine grid (8) of the first battery cell (1). Multiple solder strips (3) connect multiple first battery cells (1) and second battery cells (2). The multiple solder strips (3) weld the N-type electrode main grid (6) and P-type electrode main grid (7) on the first battery cell (1) and the second battery cell (2) in sequence. The number of the segment gaps (4) is set to 2-7, and the width of the segment gaps (4) is set to 0.5-1.2 mm.

2. A multi-segment back-contact photovoltaic module, characterized in that, This includes multiple segmented back-contact solar cells as described in claim 1.

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