Battery piece and photovoltaic module

Abstract

The utility model relates to a battery piece and a photovoltaic assembly. Wherein the battery piece is provided with a grid line and a welding strip arranged on the outer surface of the grid line, the shape of the welding strip is matched with the shape of the grid line, the periphery of the cross section of the grid line comprises an extension section extending along a first direction and a connection section connected with the extension section, the welding strip covers the outer surface of the connection section, the average thickness of the welding strip close to the extension section is H, the section width of the outer edge of the welding strip in the direction perpendicular to the first direction is W1, the section width of the outer periphery of the grid line in the direction perpendicular to the first direction is W2, and H, W1 and W2 meet the condition that W1 is smaller than W2 + 2H. According to the battery piece, a photovoltaic module manufactured by the battery piece has high reliability, and meanwhile, the battery piece also has high photovoltaic efficiency.

Description

TECHNICAL FIELD

[0001] The utility model relates to photovoltaic power generation technical field, especially battery piece and photovoltaic module. BACKGROUND

[0002] At present, the main technical direction of photovoltaic module is to reduce cost and improve efficiency, in order to reduce cost and improve efficiency, usually grid line and solder strip thin line, in order to reduce its material usage. However, with the narrowing of grid line and solder strip, the contact area of solder strip and grid line is further reduced, therefore, when thermal expansion and contraction and acidic substances corrosion occur in the operation process of photovoltaic module, the solder strip and grid line are easily separated, which affects the reliability of photovoltaic module. SUMMARY

[0003] Therefore, it is necessary to provide a battery piece and photovoltaic module for the above problems. The battery piece can make the photovoltaic module have high reliability and high photovoltaic efficiency.

[0004] A battery piece, the battery piece is provided with a grid line and a solder strip arranged on the outer surface of the grid line, the shape of the solder strip matches the shape of the grid line, the outer periphery of the cross section of the grid line includes an extension section extending along a first direction and a connecting section connected with the extension section, the solder strip covers the outer surface of the connecting section, the average thickness of the solder strip close to the extension section is H, the cross-sectional width of the outer edge of the solder strip perpendicular to the first direction is W1, the cross-sectional width of the outer periphery of the grid line perpendicular to the first direction is W2, H, W1 and W2 satisfy: W1 < W2 + 2H.

[0005] In one embodiment, H, W1 and W2 satisfy: W2 + H < W1 < W2 + 2H.

[0006] In one embodiment, the W2 of the grid line is 5-200 μm, the minimum cross-sectional width of the outer periphery of the grid line perpendicular to the first direction is 0.01-200 μm;

[0007] And / or, the W1 of the solder strip is 10-450 μm, the minimum cross-sectional width of the outer edge of the solder strip perpendicular to the first direction is 10-450 μm;

[0008] And / or, the average thickness H of the solder strip close to the extension section is 2.5-125 μm.

[0009] In one embodiment, the cross-sectional shape of the connecting section of the grid line is inverted V-shaped, and the cross-sectional shape of the solder strip is inverted V-shaped or triangular ring-shaped;

[0010] Alternatively, the cross-sectional shape of the connecting section of the gate line is circular arc shape, and the cross-sectional shape of the solder strip is semi-circular ring shape or circular arc shape.

[0011] Alternatively, the cross-sectional shape of the connecting section of the gate line is inverted U shape, and the cross-sectional shape of the solder strip is inverted U shape.

[0012] In one embodiment, when the cross-sectional shape of the connecting section of the gate line and / or the solder strip has an edge corner, the edge corner is a circular arc corner.

[0013] In one embodiment, the solder strip comprises a substrate and a conductive coating layer covering the surface of the substrate, wherein the average thickness of the conductive coating layer is 1 μm-50 μm.

[0014] In one embodiment, the substrate is selected from copper substrate or aluminum substrate.

[0015] And / or, the conductive coating layer is selected from any one of tin alloy layer, tin-lead alloy layer, tin-lead-silver alloy layer, tin-silver alloy layer, tin-silver-bismuth alloy layer or tin-lead-bismuth alloy layer.

[0016] In one embodiment, a solder layer is further provided between the gate line and the solder strip.

[0017] Alternatively, a conductive adhesive layer is further provided between the gate line and the solder strip.

[0018] A photovoltaic module comprises a plurality of cell pieces, the cell pieces are the cell pieces described above, and the solder strips on adjacent two cell pieces are connected.

[0019] In one embodiment, the back surface of the cell piece is provided with the solder strip, the solder strips on adjacent two cell pieces are directly connected, and the cross-sectional shape of the solder strips on adjacent two cell pieces is the same.

[0020] The battery piece of the utility model discloses, through covering the welding band on the outer surface of the connecting section of the grid line, can effectively increase the mutual contact area between the welding band and the grid line, prevent the relative displacement between the welding band and the grid line, can also resist the thermal stress and corrosion phenomenon generated in the operation process of the photovoltaic module later, realize the stable connection of the welding band and the grid line, thereby improve the reliability of photovoltaic module, simultaneously, through the relationship between the average thickness H of welding band close to the extension section, the cross section width W1 of the outer edge of welding band along the perpendicular to the first direction, the cross section width W2 of the outer periphery of the grid line along the perpendicular to the first direction, can effectively balance the contact area between the welding band and the grid line and the relationship of the light shielding area of welding band, make in further improve the contact area between the welding band and the grid line, compared with the setting mode between the traditional welding band and the grid line, can effectively reduce the light shielding area of welding band, thereby can improve the photovoltaic efficiency of photovoltaic module while improving the reliability of photovoltaic module. Therefore, the battery piece of the utility model can make the photovoltaic module prepared by it have high reliability, and also have high photovoltaic efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description, obviously, the drawings in the following description only are some embodiments in the utility model, for ordinary skilled person in the art, under the premise of not paying creative labor, still can obtain other drawings according to these drawings.

[0022] Figure 1 It is the cross section schematic view of the battery piece of the first embodiment of the utility model after the assembly of the grid line and the welding band.

[0023] Figure 2 It is the cross section schematic view of the battery piece of the second embodiment of the utility model after the assembly of the grid line and the welding band.

[0024] Figure 3 It is the cross section schematic view of the battery piece of the third embodiment of the utility model after the assembly of the grid line and the welding band.

[0025] Figure 4 It is the cross section schematic view of the battery piece of the fourth embodiment of the utility model after the assembly of the grid line and the welding band.

[0026] Figure 5 It is the cross section schematic view of the battery piece of the fourth embodiment of the utility model after the assembly of the grid line and the welding band.

[0027] Figure 6 It is the cross section schematic view of the photovoltaic module of an embodiment of the utility model, and the first welding band, the flat transition section and the second welding band are connected.

[0028] Reference signs:

[0029] 1 grid line; 2 solder strip; 3 connecting section; 4 extending section; 5 flat transition section. DETAILED DESCRIPTION

[0030] For the purpose of facilitating the understanding of the present application, the present application will be described in more detail below. However, it should be understood that the present application can be realized in many different forms and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the disclosure of the present application more thorough and comprehensive.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments or examples only and is not intended to be limiting of the present application. As used herein, the term "and / or" is intended to include any and all combinations of one or more of the associated listed items.

[0032] The battery piece provided by the present application is provided with a grid line 1 and a solder strip 2 arranged on the outer surface of the grid line 1. It can be understood that the grid line 1 includes a main grid line and a sub grid line, and the solder strip 2 can be arranged on the outer surface of the main grid line or the outer surface of the sub grid line, i.e. the outer surface of the fine grid line. In the present application, the solder strip 2 is preferably arranged on the outer surface of the sub grid line. Such arrangement is conducive to reducing the width of the solder strip 2, reducing the light-shielding area of the solder strip 2, and reducing the use amount of solder strip 2 material and the cost.

[0033] However, the reduction of the width of the solder strip 2 also correspondingly reduces the contact area between the solder strip 2 and the grid line 1, so that the connection strength between the solder strip 2 and the grid line 1 is poor. When thermal expansion and contraction and acid corrosion occur during the operation of the photovoltaic module, the solder strip 2 and the grid line 1 are easily separated, which affects the reliability of the photovoltaic module.

[0034] Therefore, in the present application, in combination with the above problems, Figures 1-5As shown, the shape of the solder strip 2 matches the shape of the grid line 1, the outer periphery of the cross section of the grid line 1 comprises an extension section 4 extending along the first direction A and a connecting section 3 connected with the extension section 4, and the solder strip 2 covers the outer surface of the connecting section 3. In the welding process, the above arrangement can not only effectively increase the mutual contact area between the solder strip 2 and the grid line 1, prevent relative displacement between the solder strip 2 and the grid line 1, reduce the occurrence of virtual welding or offset phenomenon, but also resist thermal stress and corrosion phenomenon generated in the operation process of the battery piece and the photovoltaic module, thereby improving the connection strength of the solder strip 2 and the grid line 1, realizing stable connection of the solder strip 2 and the grid line 1, and improving the reliability of the battery piece and the photovoltaic module.

[0035] Further, the average thickness of the solder strip 2 near the extension section 4 is H, the cross-sectional width of the outer edge of the solder strip 2 perpendicular to the first direction A is W1, and the cross-sectional width of the outer periphery of the grid line 1 perpendicular to the first direction A is W2. H, W1 and W2 satisfy: W1 < W2 + 2H. It can be understood that by limiting the relationship among the average thickness H of the solder strip 2 near the extension section 4, the cross-sectional width W1 of the outer edge of the solder strip 2 perpendicular to the first direction A, and the cross-sectional width W2 of the outer periphery of the grid line 1 perpendicular to the first direction A, the relationship between the contact area between the solder strip 2 and the grid line 1 and the light shielding area of the solder strip 2 can be effectively balanced. Compared with the arrangement between the conventional solder strip 2 and the grid line 1, the contact area between the solder strip 2 and the grid line 1 can be further increased, and the light shielding area of the solder strip 2 can be effectively reduced, thereby improving the photovoltaic efficiency of the photovoltaic module while improving the reliability of the photovoltaic module.

[0036] Therefore, the battery piece of the utility model can effectively increase the mutual contact area between the solder strip 2 and the grid line 1, realize stable connection of the solder strip 2 and the grid line 1, thereby making the photovoltaic module prepared therefrom have high reliability and high photovoltaic efficiency.

[0037] Optionally, H, W1 and W2 satisfy: W2 + H < W1 < W2 + 2H. Such arrangement is conducive to further reducing the light shielding area of the solder strip and further improving the photovoltaic efficiency of the photovoltaic module.

[0038] It should be noted that in the utility model, the cross-sectional width refers to the maximum distance between the two outer sides of the cross section. It can be understood that the cross-sectional width in the utility model refers to the maximum width of the cross section.

[0039] Optionally, W2 of the grid line 1 is 5-200 μm, the minimum width of the outer peripheral edge of the grid line 1 along the cross section perpendicular to the first direction A is 0.01-200 μm; W1 of the solder strip 2 is 10-450 μm, the minimum width of the outer edge of the solder strip 2 along the cross section perpendicular to the first direction A is 10-450 μm; in this way, the contact area between the solder strip 2 and the grid line 1 can be better controlled by adjusting W2 of the grid line 1, the minimum width of the cross section and W1 and the minimum width of the cross section of the solder strip 2, which is conducive to further improving the welding stability of the solder strip 2 and the grid line 1 and improving the reliability of the battery piece and the photovoltaic module.

[0040] Further, the average thickness H of the solder strip 2 close to the extension section 4 is 2.5-125 μm. In this way, the relationship between the contact area between the solder strip 2 and the grid line 1 and the light shielding area of the solder strip 2 can be better balanced, so that the battery piece and the photovoltaic module have the characteristics of high reliability and high photovoltaic efficiency.

[0041] In the utility model, the structure of the solder strip 2 can be designed according to the structure of the grid line 1, so that the cross-sectional shape of the solder strip 2 matches the cross-sectional shape of the connecting section 3 of the grid line 1, so as to cover the solder strip 2 on the outer surface of the connecting section 3.

[0042] Specifically, as shown in Figure 1 , the cross-sectional shape of the connecting section 3 of the grid line 1 is inverted V-shaped, and the cross-sectional shape of the solder strip 2 is inverted V-shaped or triangular ring-shaped.

[0043] As shown in Figure 2 , when the cross-sectional shape of the connecting section 3 of the grid line 1 is circular arc-shaped, the cross-sectional shape of the solder strip 2 is semicircular ring-shaped or circular arc-shaped.

[0044] As shown in Figure 3 , when the cross-sectional shape of the connecting section 3 of the grid line 1 is trapezoidal, the cross-sectional shape of the solder strip 2 is inverted U-shaped.

[0045] In an embodiment, the cross-sectional shape of the connecting section 3 of the grid line 1 is inverted U-shaped, that is, the cross-sectional shape of the grid line 1 is rectangular, and the cross-sectional shape of the solder strip 2 is inverted U-shaped.

[0046] Optionally, when the cross-sectional shape of the connecting section 3 of the grid line 1 and / or the solder strip 2 has a corner, the corner is a circular arc corner.

[0047] Specifically, as shown in Figure 4 , the cross-sectional shape of the connecting section 3 of the grid line 1 is inverted V-shaped, that is, the cross-sectional shape of the grid line 1 is triangular, and the cross-sectional shape of the solder strip 2 is inverted V-shaped, and the corner of the corresponding inverted V-shaped is a circular arc corner.

[0048] As shown in Figure 5As shown, the cross-sectional shape of the connecting section 3 of the gate line 1 is inverted U-shaped, that is, the cross-sectional shape of the gate line 1 is trapezoidal, and the cross-sectional shape of the solder strip 2 is inverted U-shaped, at this time, the corners of the inverted U-shaped are all circular arc corners.

[0049] In an embodiment, the cross-sectional shape of the connecting section 3 of the gate line 1 is inverted U-shaped, that is, the cross-sectional shape of the gate line 1 can also be rectangular, and the corners of the rectangular are circular arc corners, and the cross-sectional shape of the solder strip 2 is inverted U-shaped, at this time, the corners of the inverted U-shaped are all circular arc corners.

[0050] In the utility model, through setting the corners of the cross-sectional shape of the connecting section 3 of the gate line 1 and / or the solder strip 2 as circular arc corners, the average thickness of the reflection structure can be reduced, stress concentration can be reduced, and the stability of the structure can be improved.

[0051] Optionally, the solder strip 2 comprises a base material and a conductive coating layer covering the surface of the base material, wherein the average thickness of the conductive coating layer is 1 μm-50 μm.

[0052] Further, the base material is selected from a copper base material or an aluminum base material; and the conductive coating layer is selected from any one of a tin alloy layer, a tin-lead alloy layer, a tin-lead-silver alloy layer, a tin-silver alloy layer, a tin-silver-bismuth alloy layer or a tin-lead-bismuth alloy layer.

[0053] In an embodiment, a welding layer (not shown in the figure) is further arranged between the gate line 1 and the solder strip 2; in this way, the welding quality between the solder strip 2 and the gate line 1 can be improved.

[0054] In another embodiment, a conductive adhesive layer (not shown in the figure) is further arranged between the gate line 1 and the solder strip 2, which is conducive to improving the stable connection between the solder strip 2 and the gate line 1.

[0055] Meanwhile, the utility model also provides a kind of photovoltaic module, including multiple cell pieces, and the cell piece is above-mentioned cell piece, and the solder strip 2 on adjacent two cell pieces is connected.

[0056] In the utility model, the solder strip 2 can be arranged on the front surface or the back surface of the cell piece according to the type of the cell piece.

[0057] In an embodiment, the back surface of the cell piece is provided with the solder strip 2, the solder strip 2 on adjacent two cell pieces is directly connected, and the shape of the cross section of the solder strip 2 on adjacent two cell pieces is the same. It can be understood that, at this time, the metal electrode on the cell piece is arranged on its back surface, which is a BC cell.

[0058] In another embodiment, the two adjacent battery pieces are a first battery piece and a second battery piece, the solder band 2 of the first battery piece is arranged on the front surface of the first battery piece and is defined as a first solder band, the solder band 2 of the second battery piece is arranged on the back surface of the second battery piece and is defined as a second solder band, and the first solder band and the second solder band are connected through the flat transition section 5. It can be understood that the metal electrodes of the first battery piece and the second battery piece are designed on the front and back surfaces thereof, and the first battery piece and the second battery piece both belong to PERC, TOPCON, HJT and laminated cells. Meanwhile, in actual application, the first battery piece and the second battery piece can also be BC cells.

[0059] Further, as shown in Figure 6 It can be understood that the cross sections of the first solder band and the second solder band are parallel, a plane parallel to the cross section of the first solder band is defined as a first plane, the length direction of the first solder band is defined as a second direction B, the first solder band, the flat transition section 5 and the second solder band are arranged in sequence along the second direction B, and the projections of the first solder band and the second solder band on the first plane along the second direction B are symmetrically arranged relative to the flat transition section 5. The thickness of the flat transition section 5 is less than the thickness of the first solder band and the thickness of the second solder band.

[0060] In an embodiment, the cross section of the flat transition section 5 is flat, and is preferably a flat rectangle.

[0061] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not contradict, they should be considered within the scope of the present disclosure.

[0062] The above-described embodiments only express several embodiments of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A battery cell, wherein the battery cell has grid lines and solder strips disposed on the outer surface of the grid lines, the shape of the solder strips matching the shape of the grid lines, and the outer periphery of the cross-section of the grid lines includes an extension segment extending along a first direction and a connecting segment connected to the extension segment, characterized in that, The solder strip covers the outer surface of the connecting section, the average thickness of the solder strip near the extension section is H, the cross-sectional width of the outer edge of the solder strip perpendicular to the first direction is W1, and the cross-sectional width of the outer periphery of the grid line perpendicular to the first direction is W2. H, W1 and W2 satisfy: W1 < W2 + 2H.

2. The battery cell according to claim 1, characterized in that, H, W1, and W2 satisfy the condition: W2 + H < W1 < W2 + 2H.

3. The battery cell according to claim 1, characterized in that, The W2 of the gate line is 5μm-200μm, and the minimum width of the cross section of the outer periphery of the gate line perpendicular to the first direction is 0.01μm-200μm; And / or, the W1 of the solder strip is 10μm-450μm, and the minimum width of the cross section of the outer edge of the solder strip perpendicular to the first direction is 10μm-450μm; And / or, the average thickness H of the solder strip near the extension is 2.5 μm-125 μm.

4. The battery cell according to claim 1, characterized in that, The cross-sectional shape of the connecting section of the grid line is an inverted V shape, and the cross-sectional shape of the solder strip is an inverted V shape or a triangular ring shape; Alternatively, the cross-sectional shape of the connecting segment of the grid line is an arc shape, and the cross-sectional shape of the welding strip is a semi-circular ring or an arc shape; Alternatively, the cross-sectional shape of the connecting segment of the grid line is an inverted U-shape, and the cross-sectional shape of the solder strip is an inverted U-shape.

5. The battery cell according to claim 4, characterized in that, When the cross-sectional shape of the connecting segment of the grid line and / or the solder strip has corners, the corners are rounded corners.

6. The battery cell according to any one of claims 1 to 5, characterized in that, The solder strip includes a substrate and a conductive coating covering the surface of the substrate, wherein the average thickness of the conductive coating is 1μm-50μm.

7. The battery cell according to claim 6, characterized in that, The substrate is selected from copper substrate or aluminum substrate; And / or, the conductive coating is selected from any one of tin alloy layer, tin-lead alloy layer, tin-lead-silver alloy layer, tin-silver alloy layer, tin-silver-bismuth alloy layer or tin-lead-bismuth alloy layer.

8. The battery cell according to any one of claims 1 to 5, characterized in that, A welding layer is also provided between the grid line and the welding strip; Alternatively, a conductive adhesive layer may be provided between the grid line and the solder strip.

9. A photovoltaic module comprising a plurality of solar cells, characterized in that, The battery cell is any one of claims 1 to 8, and the solder strips on two adjacent battery cells are connected.

10. The photovoltaic module according to claim 9, characterized in that, The back of the battery cell is provided with the solder strip, the solder strips on two adjacent battery cells are directly connected, and the cross-sectional shape of the solder strips on two adjacent battery cells is the same.

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