Electrode structure of back contact battery, back contact battery and back contact battery assembly

Abstract

The invention is applicable to the field of photovoltaic technology, and provides an electrode structure of a back contact battery, the back contact battery and a back contact battery assembly, and the electrode structure comprises a plurality of fine grids which extend along a first direction and are alternately distributed at intervals along a second direction; the plurality of main grids extend along the second direction and are alternately distributed at intervals along the first direction; the back contact battery comprises a plurality of main grids and a plurality of fine grids, each of the plurality of main grids and the plurality of fine grids are arranged in a crossed manner, and each of the plurality of main grids is provided with a part extending out of the outer side of the fine grid close to the edge of the back contact battery along the second direction. The main grid is provided with a part extending out of the outer side of the fine grid close to the edge of the back contact battery along the second direction, and the main grid is subjected to redundancy design, so that even if the main grid slightly deviates in the printing process, the main grid cannot be separated from the fine grid at the edge of the battery, the requirement on the printing precision of the main grid is reduced, and the yield of a product assembly is improved.

Description

Technical Field

[0001] The present application belongs to the field of photovoltaic technology, and in particular relates to an electrode structure of a back-contact cell, a back-contact cell and a back-contact cell assembly. Background Art

[0002] The back-contact battery concentrates the front electrode grid lines and PN junction of the battery cell on the back side, reducing the obstruction of the front grid lines of the battery cell, having a higher photon impact conversion area, and improving the conversion efficiency of the battery cell.

[0003] In the related art, there are multiple main grids on the back of the battery cell, with the positive and negative main grids adjacent to each other, and the fine grid lines are divided into positive and negative and converge to the corresponding polarity main grids. The main grid and the fine grid of the battery are overlapped by step-by-step printing. After the fine grid is printed, the main grid is printed. If the main grid printing process is slightly offset, the main grid is easy to separate from the fine grid at the edge of the battery. This requires high printing accuracy of the main grid, and there is a high defective rate in the production process.

[0004] Application Contents

[0005] The present application provides an electrode structure for a back-contact battery, aiming to solve the problem that if the main grid is slightly offset during the printing process, the main grid is easily separated from the fine grid at the edge of the battery. This requires high printing accuracy of the main grid and there is a high defect rate in the production process.

[0006] The present application is implemented as follows: an electrode structure of a back-contact battery includes: fine grids, multiple fine grids extending along a first direction and alternately distributed along a second direction; main grids, multiple main grids extending along the second direction and alternately distributed along the first direction; each of the multiple main grids is cross-arranged with the multiple fine grids, respectively, and the multiple main grids and the multiple fine grids are electrically contacted with each other of the multiple main grids of the same polarity, and each of the multiple main grids has a portion extending along the second direction from the outside of the fine grid close to the edge of the back-contact battery.

[0007] Optionally, each of the plurality of main grids has a first portion extending out of the outer side of the fine grid close to the first edge of the back contact cell along the second direction.

[0008] Optionally, each of the plurality of main grids has a second portion extending out of the outer side of the fine grid close to a second edge of the back contact cell along the second direction, and the second edge is opposite to the first edge.

[0009] Optionally, a length of the first portion in the second direction is greater than or equal to 5 mm and less than or equal to 30 mm.

[0010] Optionally, a length of the first portion in the second direction is greater than or equal to 10 mm and less than or equal to 20 mm.

[0011] Optionally, a length of the second portion in the second direction is greater than or equal to 5 mm and less than or equal to 30 mm.

[0012] Optionally, a length of the second portion in the second direction is greater than or equal to 10 mm and less than or equal to 20 mm.

[0013] Optionally, the length of the first portion is equal to the length of the second portion.

[0014] Optionally, a distance between the first portion and the first edge of the back contact battery is greater than or equal to 5 mm and less than or equal to 20 mm.

[0015] Optionally, a distance between the second portion and the second edge of the back contact battery is greater than or equal to 5 mm and less than or equal to 20 mm.

[0016] In the solution of the present application, each of the multiple main grids is cross-arranged with the multiple fine grids, and the main grid has a portion extending along the second direction to the outside of the fine grid close to the edge of the back contact battery. By designing the main grid redundantly, even if the main grid is slightly offset during the printing process, the main grid will not be separated from the fine grid at the edge of the battery, thereby reducing the printing accuracy requirements for the main grid and improving the yield of the product components.

[0017] A solar cell comprises the above-mentioned solar cell electrode structure.

[0018] A solar cell assembly comprises the above-mentioned solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the electrode structure of the back contact battery provided in the present application;

[0020] Figure 2 yes Figure 1 A magnified view of the structure at A;

[0021] Figure 3 yes Figure 1 Enlarged view of the structure at B.

[0022] Description of reference numerals:

[0023] 100, fine grid; 101, first fine grid; 102, second fine grid; 200, main grid; 201, first main grid; 202, second main grid; 300, part; 301, first part; 302, second part; 400, battery cell; 500, insulating glue. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. In addition, it should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0025] In the description of the present application, it should be understood that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0026] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0027] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0028] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0029] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the various specific processes and material examples provided by the present application, but those of ordinary skill in the art can appreciate the application of other processes and / or the use of other materials.

[0030] like Figure 1 As shown, an electrode structure of a back-contact battery includes a fine grid 100 and a main grid 200 . The fine grid 100 includes a first fine grid 101 and a second fine grid 102 . The main grid 200 includes a first main grid 201 and a second main grid 202 .

[0031] In some embodiments, multiple fine grids 100 extend along the first direction and are alternately distributed along the second direction, and multiple main grids 200 extend along the second direction and are alternately distributed along the first direction; each of the multiple main grids 200 is cross-arranged with the multiple fine grids 100, respectively, and the multiple main grids 200 and the multiple fine grids 100 have electrical contacts of the same polarity, and each of the multiple main grids 200 has a portion 300 extending along the second direction from the outside of the fine grid 100 near the edge of the back contact battery.

[0032] Specifically, the plurality of fine gates 100 include a plurality of first fine gates 101 and a plurality of second fine gates 102, the first fine gates 101 and the second fine gates 102 are alternately arranged along the second direction, and the first fine gates 101 and the second fine gates 102 have opposite polarities, and the plurality of main gates 200 include a plurality of first main gates 201 and a plurality of second main gates 202, the first main gates 201 and the second main gates 202 are alternately arranged along the first direction, and the first main gates 201 and the second main gates 202 have opposite polarities, wherein the first The fine gate 101 has the same polarity as the first main gate 201, the second fine gate 102 has the same polarity as the second main gate 202, each of the multiple first main gates 201 crosses and contacts with the multiple first fine gates 101 respectively, each of the multiple first main gates 201 is insulated from the multiple second fine gates 102 respectively, each of the multiple second main gates 202 crosses and contacts with the multiple second fine gates 102 respectively, and each of the multiple second main gates 202 is insulated from the multiple first fine gates 101 respectively.

[0033] The first main grid 201 and the second fine grid 102 may be insulated in a form that the second fine grid 102 forms a disconnected structure at the first main grid 201, and the second fine grid 102 is physically isolated from the first main grid 201 and does not contact, or an insulating glue is set between the second fine grid 102 and the first main grid 201, and the second main grid 202 and the first fine grid 101 may be insulated in a form that the first fine grid 101 forms a disconnected structure at the second main grid 202, and the first fine grid 101 is physically isolated from the second main grid 202 and does not contact, or an insulating glue is set between the first fine grid 101 and the second main grid 202, and the main grid 200 and the fine grid 100 with different polarities are insulated from each other, thereby preventing the solar cell from short-circuiting. In the embodiment of the present application, preferably, an insulating glue 500 is set between the second fine grid 102 and the first main grid 201, and an insulating glue 500 is set between the first fine grid 101 and the second main grid 202.

[0034] In the embodiment of the present application, the second direction intersects with the first direction. Specifically, the second direction may be perpendicular to the first direction. Exemplarily, the first direction may be the width direction of the battery cell, and the second direction may be the length direction of the battery cell.

[0035] In some embodiments, the first fine grid 101 and the second fine grid 102 may be formed by screen printing a metal paste onto the surface of the cell 400 to form a fine grid 100 line on the surface of the cell. The metal paste may be a silver paste, an aluminum paste, etc. Here, there is no limitation on the specific material of the metal paste, and in actual use, technicians may select a suitable material according to requirements.

[0036] In some embodiments, the first busbar 201 and the second busbar 202 may be formed by screen printing a metal paste onto the surface of the cell 400 to form a busbar 200 line on the surface of the cell. The metal paste may be a silver paste, an aluminum paste, etc. Here, there is no limitation on the specific material of the metal paste, and in actual use, technicians may select a suitable material according to requirements.

[0037] like Figure 2 and Figure 3As shown, in some embodiments, each of the plurality of main grids 200 has a portion 300 extending outward from the thin grid 100 near the edge of the back contact battery along the second direction. Specifically, the back contact battery has a first edge and a second edge relative to each other in the second direction, wherein each of the plurality of main grids 200 has a first portion 301 extending outward from the thin grid 100 near the first edge of the back contact battery along the second direction, and each of the plurality of main grids 200 has a second portion 302 extending outward from the thin grid 100 near the second edge of the back contact battery along the second direction. That is, the first main grid 201 and the second main grid The first main grid 201 and the second main grid 202 both have a first portion 301 extending outward from the thin grid 100 near the first edge of the back contact battery, and / or the first main grid 201 and the second main grid 202 both have a second portion 302 extending outward from the thin grid 100 near the second edge of the back contact battery. Preferably, the first main grid 201 and the second main grid 202 both have a first portion 301 and a second portion 302. In this way, when printing the main grid 200, the main grid 200 has redundant parts outside the thin grid 100 near the first edge and outside the thin grid 100 near the second edge, further reducing the printing accuracy requirements of the main grid 200 and improving the yield rate of battery cell production. Preferably, the length of the first portion 301 and the length of the second portion 302 are equal. In this way, the distance between the main grid 200 and the first edge and the second edge can be better controlled, which facilitates the printing of the main grid 200.

[0038] Further, the length of the first portion 301 in the second direction is greater than or equal to 5 mm and less than or equal to 30 mm. Specifically, in such an embodiment, the length of the first portion 301 can be 5 mm, 10 mm, 15 mm, 20 mm, 30 mm or any value between 5-30 mm, which is not specifically limited herein. Preferably, the length of the first portion 301 is greater than or equal to 10 mm and less than or equal to 20 mm. Specifically, in such an embodiment, the length of the first portion 301 can be 10 mm, 15 mm, 20 mm or any value between 10-20 mm, which is not specifically limited herein. In this way, the main grid 200 has a redundant portion of sufficient length outside the fine grid 100 near the first edge, and even if the main grid 200 is offset during the printing process, it can still ensure that the main grid 200 and the fine grid 100 near the first edge are connected.

[0039] Further, the length of the second portion 302 in the second direction is greater than or equal to 5 mm and less than or equal to 30 mm. Specifically, in such an embodiment, the length of the second portion 302 can be 5 mm, 10 mm, 15 mm, 20 mm, 30 mm or any value between 5-30 mm, which is not specifically limited herein. Preferably, the length of the second portion 302 in the second direction is greater than or equal to 10 mm and less than or equal to 20 mm. Specifically, in such an embodiment, the length of the second portion 302 can be 10 mm, 15 mm, 20 mm or any value between 10-20 mm, which is not specifically limited herein. In this way, the main grid 200 has a redundant portion 300 of sufficient length outside the fine grid 100 near the second edge, and even if the main grid 200 is offset during the printing process, it can still ensure that the main grid 200 and the fine grid 100 near the second edge are connected.

[0040] In some embodiments, along the first direction, the length of the first fine grid line 101 matches the width of the cell. It can also be understood that along the first direction, the length of the first fine grid line 101 is equal to the width of the cell.

[0041] Preferably, along the first direction, the length of the second fine grid 102 line is adapted to the width of the battery cell. It can also be understood that along the first direction, the length of the second fine grid 102 line is equal to the width of the battery cell.

[0042] In some embodiments, the distance between the first portion 301 and the first edge of the back contact battery is greater than or equal to 5 mm and less than or equal to 20 mm. This refers to the distance between the edge of the first portion 301 close to the first edge and the first edge. Preferably, the distance between the first portion 301 and the first edge of the back contact battery is greater than or equal to 15 mm and less than or equal to 20 mm. During the component packaging process, the edge of the battery cell may be affected by mechanical stress or thermal stress. Keeping the main grid 200 at an appropriate distance from the edge of the battery can reduce the impact of these stresses on the main grid 200 and its connection points, thereby improving the reliability and durability of the component.

[0043] In some embodiments, the distance between the second portion 302 and the second edge of the back contact battery is greater than or equal to 5 mm and less than or equal to 20 mm. This refers to the distance between the edge of the second portion 302 close to the second edge and the second edge. Preferably, the distance between the second portion 302 and the second edge of the back contact battery is greater than or equal to 15 mm and less than or equal to 20 mm. During the component packaging process, the edge of the battery cell may be affected by mechanical stress or thermal stress. Keeping the main grid 200 at an appropriate distance from the edge of the battery can reduce the impact of these stresses on the main grid 200 and its connection points, thereby improving the reliability and durability of the component.

[0044] In the solution of the present application, each of the multiple main grids 200 is cross-arranged with the multiple fine grids 100, and the main grid 200 has a portion 300 extending along the second direction to the outside of the fine grid 100 close to the edge of the back contact battery. By designing the main grid 200 redundantly, even if the main grid 200 is slightly offset during the printing process, the main grid 200 will not be separated from the fine grid 100 at the edge of the battery, thereby reducing the printing accuracy requirements for the main grid 200 and improving the yield rate of the product components.

[0045] A solar cell includes the above-mentioned solar cell electrode structure. The technical effect of the solar cell is the same as the technical effect of the solar cell electrode structure, which will not be described in detail here.

[0046] A solar cell assembly includes the above-mentioned solar cell. Based on the above-mentioned solar cell, those skilled in the art know that a corresponding battery assembly can be obtained by using a plurality of the solar cells and / or other corresponding existing accessories.

[0047] In this embodiment, a plurality of solar cells in the battery assembly can be connected in series in sequence to form a battery string, thereby realizing the series bus output of the current. For example, the series connection of the battery cells can be realized by providing welding strips (bus bars, interconnecting strips), conductive backplanes, etc. It can be understood that in such an embodiment, the battery assembly may also include a metal frame, a backplane, photovoltaic glass, and an adhesive film. The adhesive film can be filled between the front and back of the back contact battery and the photovoltaic glass, adjacent battery cells, etc. As a filler, it can be a transparent colloid with good light transmittance and aging resistance. For example, the adhesive film can be an EVA adhesive film or a POE adhesive film. The specific selection can be made according to the actual situation and is not limited here.

[0048] In the description of this specification, the description with reference to the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0049] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An electrode structure of a back contact battery, characterized in that: include: A fine grid, wherein a plurality of the fine grids extend along a first direction and are alternately distributed along a second direction; a main grid, wherein a plurality of the main grids extend along a second direction and are alternately distributed along the first direction; each of the plurality of the main grids is respectively cross-arranged with the plurality of the fine grids, and the plurality of the main grids and the plurality of the fine grids are electrically contacted with each other of the plurality of the main grids of the same polarity, and each of the plurality of the main grids has a portion extending outward of the fine grid near the edge of the back contact battery along the second direction.

2. The electrode structure of the back contact battery according to claim 1, characterized in that: Each of the plurality of main grids has a first portion extending outwardly of the thin grid near the first edge of the back contact cell along the second direction.

3. The electrode structure of the back contact battery according to claim 2, characterized in that: Each of the plurality of main grids has a second portion extending outward from the outer side of the fine grid near a second edge of the back contact cell along the second direction, the second edge being opposite to the first edge.

4. The electrode structure of the back contact battery according to claim 2, characterized in that: The length of the first portion in the second direction is greater than or equal to 5 mm and less than or equal to 30 mm.

5. The electrode structure of the back contact battery according to claim 2, characterized in that: The length of the first portion in the second direction is greater than or equal to 10 mm and less than or equal to 20 mm.

6. The electrode structure of the back contact battery according to claim 3, characterized in that: The length of the second portion in the second direction is greater than or equal to 5 mm and less than or equal to 30 mm.

7. The electrode structure of the back contact battery according to claim 3, characterized in that: The length of the second portion in the second direction is greater than or equal to 10 mm and less than or equal to 20 mm.

8. The electrode structure of the back contact battery according to claim 3, characterized in that: The length of the first portion is equal to the length of the second portion.

9. The electrode structure of the back contact battery according to claim 2, characterized in that: The distance between the first portion and the first edge of the back contact battery is greater than or equal to 5 mm and less than or equal to 20 mm.

10. The electrode structure of the back contact battery according to claim 3, characterized in that: The distance between the second portion and the second edge of the back contact battery is greater than or equal to 5 mm and less than or equal to 20 mm.

11. A back contact battery, characterized in that: The back contact cell comprises the electrode structure according to any one of claims 1 to 10.

12. A back contact battery assembly, characterized in that: The back contact cell assembly comprises the back contact cell of claim 11.

Images