CN210866198U

CN210866198U - PERC double-sided battery and photovoltaic module

Info

Publication number: CN210866198U
Application number: CN201922258194.6U
Authority: CN
Inventors: 李兵; 杨慧; 邓伟伟; 蒋方丹
Original assignee: CSI Cells Co Ltd; CSI Solar Power Group Co Ltd
Current assignee: Canadian Solar Inc; CSI Cells Co Ltd
Priority date: 2019-12-16
Filing date: 2019-12-16
Publication date: 2020-06-26
Anticipated expiration: 2029-12-16

Abstract

The utility model discloses a PERC double-sided battery and photovoltaic module, the PERC double-sided battery that relates includes the silicon chip, the silicon chip back is provided with the passivation layer, PERC double-sided battery still have set up in the back electrode at the passivation layer back, the back electrode includes a plurality of pad groups that set up along the first direction interval, each pad group includes a plurality of edges perpendicular to the second direction interval distribution's of first direction pad, in using the pad as the original point, using the straight line that extends along the first direction as the cross axle, using the straight line that extends along the second direction as the coordinate system of axis of ordinates, the back electrode still includes four all to be connected to this pad and towards the electrode sublister of four different quadrant extensions; based on the utility model discloses in the concrete design structure of related back electrode, can effectively optimize the transmission path of PERC double-sided battery back electric current, and then can effectively improve PERC double-sided battery's battery efficiency.

Description

PERC double-sided battery and photovoltaic module

Technical Field

The utility model relates to a solar photovoltaic technology field especially relates to a PERC double-sided battery and photovoltaic module.

Background

The PERC bifacial cell is a photovoltaic device that can receive light on both the front and back sides to generate an electric current. The double-sided component manufactured by the PERC double-sided battery has the advantages that the back can also generate electricity, and compared with a single-sided battery component, the total generated energy can be greatly increased. Referring to fig. 1, a PERC double-sided battery in the prior art generally includes a silicon wafer 100 ', and a silver electrode and an aluminum back field disposed on the back of the silicon wafer 100'. Wherein, the silver electrode comprises a plurality of intermittent silver main grids 200' which are arranged in parallel at intervals; the aluminum back field comprises a plurality of aluminum grid lines 31 'which are distributed in parallel at intervals along the length direction of the silver main grid 200' and a plurality of aluminum main grids 32 'which are used for connecting with a plurality of discontinuous parts of the silver electrode 200' in series.

Based on the structure of the conventional PERC dual-sided battery, referring to fig. 2, the current transmission mode from the back aluminum gate line 31 'to the silver main gate 200' mainly includes two types: the first is that the collected aluminum grid lines 31 'are directly converged to the silver main grid 200', and the farthest path of the current transmitted from the corresponding aluminum grid line 31 'to the silver main grid 200' is half the length of the aluminum grid line 31 'between two adjacent silver main grids 200'; the other is that the collected current is converged to the aluminum main grid 32 ' by the aluminum grid line 31 ' and then transmitted to the silver main grid 200 ', and the farthest path of the current transmitted from the corresponding aluminum grid line 31 ' to the silver main grid 200 ' is larger than that of the first mode. In the prior art, the aluminum grid lines 31 'and the aluminum main grids 32' both have larger resistivity, and the transmission of the current in the aluminum grid lines 31 'or the aluminum main grids 32' for a longer distance is not beneficial to improving the battery efficiency of the PERC double-sided battery.

In view of the above, it is necessary to provide a technical solution to solve the above technical problems.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving one of the technical problem that prior art exists at least, for realizing the above-mentioned utility model purpose, the utility model provides a PERC double-sided battery, its concrete design as follows.

The utility model provides a PERC double-sided battery, includes the silicon chip, the silicon chip back is provided with the passivation layer, PERC double-sided battery still have set up in the back electrode at the passivation layer back, the back electrode includes a plurality of pad groups that set up along first direction interval, each pad group includes a plurality of edges perpendicular to the second direction interval distribution's of first direction pad, use the pad is the original point, with the edge the straight line that first direction extends is the cross axle, with the edge the straight line that the second direction extends is in the coordinate system of axis of ordinates, the back electrode still includes four all to this the pad just extends towards four different quadrants's electrode auxiliary grid.

Furthermore, the bonding pads of two adjacent bonding pad groups are arranged in a one-to-one correspondence manner in the second direction, and in a quadrilateral region with two adjacent bonding pads on one bonding pad group and two corresponding bonding pads on the other adjacent bonding pad group as vertexes, four corresponding bonding pads are connected with one electrode sub-grid positioned in the quadrilateral region, and the four electrode sub-grids are intersected at one point.

Furthermore, the quadrilateral area is rectangular, and the point where the four electrode auxiliary grids in the quadrilateral area meet is the central point of the rectangle.

Further, the width of the electrode subgrids has a tendency to become gradually smaller in a direction away from the corresponding pad.

Furthermore, the width range of one end of the electrode auxiliary grid, which is far away from the corresponding bonding pad, is 0.03mm-0.1mm, and the width range of one end of the electrode auxiliary grid, which is close to the corresponding bonding pad, is 0.1mm-1 mm.

Further, the pad is circular or rectangular.

Further, the pad is circular, and the diameter range of the pad is 0.2mm-4 mm.

Furthermore, the bonding pad is rectangular, the width range of the bonding pad in the first direction is 1mm-4mm, and the length range of the bonding pad in the second direction is 2-20 mm.

Further, the PERC double-sided battery further comprises a back electric field which is arranged on the back of the passivation layer and electrically connected with the silicon wafer and the back electrode, and the back electric field comprises a plurality of back field auxiliary grids which are distributed along the second direction at intervals in parallel.

The utility model also provides a photovoltaic module, this photovoltaic module including above PERC double-sided battery.

The utility model has the advantages that: the utility model provides a PERC double-sided battery with brand-new back electrode structure, based on the utility model discloses in the concrete design structure of relevant back electrode, can effectively optimize the transmission path of PERC double-sided battery back current, and then can effectively improve PERC double-sided battery's battery efficiency.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic diagram of the overall structure of the back side of a prior art PERC double-sided battery;

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

fig. 3 is a schematic diagram of a design structure of a back electrode of a PERC double-sided battery according to the present invention;

FIG. 4 is an enlarged view of portion b of FIG. 3;

fig. 5 is a schematic view of the overall structure of the back side of the PERC double-sided battery of the present invention;

FIG. 6 is an enlarged view of portion c of FIG. 5;

fig. 7 is another schematic diagram of the overall structure of the backside of the PERC double-sided battery according to the present invention.

In the figure, 100 'is a silicon wafer of a PERC double-sided battery in the prior art, 200' is a silver main grid, 31 'is an aluminum grid line, and 32' is an aluminum main grid; 100 is a silicon wafer, 200 is a back electrode, 21 is a pad, 211 is a first pad, 212 is a second pad, 213 is a third pad, 214 is a fourth pad, 22 is an electrode subgrid, 220 is an intersection, 221 is a first electrode subgrid, 222 is a second electrode subgrid, 223 is a third electrode subgrid, 224 is a fourth electrode subgrid, 300 is a back electric field, and 30 is a back field subgrid.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 3, the PERC double-sided battery provided by the present invention includes a silicon wafer 100, a passivation layer is disposed on the back of the silicon wafer 100, and the PERC double-sided battery further has a back electrode 200 disposed on the back of the passivation layer. The back electrode 200 includes a plurality of pad groups spaced apart along a first direction D1, and each pad group includes a plurality of pads 21 spaced apart along a second direction D2 perpendicular to the first direction D1. In the embodiment shown in fig. 3, the back electrode 200 includes five groups of pads spaced apart along the first direction D1, and each group of pads includes five pads 21 spaced apart along the second direction D2.

Further, referring to fig. 3, the back electrode 200 further includes four electrode sub-grids 22 each connected to the pad 21 and extending toward four different quadrants, in a coordinate system with the pad 21 as an origin, with a horizontal axis being a straight line extending in the first direction D1, and a vertical axis being a straight line extending in the second direction D2. It will be appreciated that in the present invention, each pad 21 is connected to an electrode subgrid 22 extending towards four different quadrants of the respective coordinates

The utility model also provides a photovoltaic module, this photovoltaic module is including the PERC double-sided battery that above relates.

The utility model discloses in, PERC double-sided battery's back electrode is different from traditional PERC double-sided battery's back electrode structure completely, based on its concrete design structure, can effectively optimize PERC double-sided battery back current's transmission path, and then can effectively improve PERC double-sided battery's battery efficiency.

Further, in some preferred embodiments of the present invention, the pads 21 of two adjacent pad groups are disposed in a one-to-one correspondence on the second direction D2, which is easy to understand, and at this time, two adjacent pad groups all have the same number of pads 21. In a quadrilateral region with two adjacent bonding pads 21 on one bonding pad group and two corresponding bonding pads 21 on the other adjacent bonding pad group as vertexes, four corresponding bonding pads 21 are connected with one electrode sub-grid 22 positioned in the corresponding quadrilateral region, and the four electrode sub-grids 22 are intersected at one point.

Specifically, as shown in fig. 3 and 4, two adjacent pads 21 on a pad group include a first pad 211 and a second pad 212, the pad group adjacent to the pad group has two pads 21 corresponding to the first pad 211 and the second pad 212 one by one, that is, a third pad 213 and a fourth pad 214, in a quadrilateral region with the first pad 211, the second pad 212, the third pad 213 and the fourth pad 214 as vertices, the first pad 211, the second pad 212, the third pad 213 and the fourth pad 214 are respectively connected with a first electrode subgrid 221, a second electrode subgrid 222, a third electrode subgrid 223 and a fourth electrode subgrid 224 located inside the quadrilateral region, and the first electrode subgrid 221, the second electrode subgrid 222, the third electrode subgrid 223 and the fourth electrode subgrid 224 intersect at a same intersection point 220.

As a further preferred aspect of the present invention, referring to fig. 4, a quadrilateral region having the first pad 211, the second pad 212, the third pad 213, and the fourth pad 214 as vertexes is rectangular, and the intersection point 220 is a central point of the rectangle. It is understood that in other embodiments of the present invention, the quadrilateral region having the first pad 211, the second pad 212, the third pad 213 and the fourth pad 214 as vertices may have other quadrilateral shapes.

It will be appreciated that during operation of the PERC double sided battery, the end of the electrode subgrid 22 near the respective pad 21 has a greater current flow than the end of the electrode subgrid 22 remote from the respective pad 21. For better matching the transmission of current in the electrode subgrids 22, the width of the electrode subgrids 22 has a tendency to become progressively smaller in a direction away from the respective pad 21.

In a specific implementation, as shown in fig. 4, the width d1 of the end of the electrode subgrid 22 away from the corresponding pad 21 ranges from 0.03mm to 0.1mm, and the width d2 of the end of the electrode subgrid 22 close to the corresponding pad 21 ranges from 0.1mm to 1 mm. To ensure that the electrode grids 22 do not produce any break points during the printing process and do not shade the back of the PERC double-sided battery to an excessively large area, the d1 range is preferably 0.03mm to 0.05mm, and the d2 range is preferably 0.2mm to 0.4mm in some embodiments of the present invention.

In the present embodiment, the related bonding pad 21 is used for being connected to the solder strip during the assembly process of the photovoltaic module, and is usually a regular pattern of some shapes such as a circle or a rectangle.

In the embodiment shown in fig. 3 and 4, the pad 21 has a circular shape, and the diameter of the pad 21 is preferably set in the range of 0.2mm to 4 mm.

In other embodiments of the present invention, the bonding pads 21 are disposed in a rectangular shape, the width of the bonding pads 21 in the first direction D1 ranges from 1mm to 4mm, and the length of the bonding pads 21 in the second direction D2 ranges from 2mm to 20 mm.

Referring to fig. 5 and 6, the PERC double-sided battery of the present invention further includes a back electric field 300 disposed at the back of the passivation layer and electrically connecting the silicon wafer 100 and the back electrode 200, wherein the back electric field includes a plurality of back field sub-grids 30 spaced apart from each other in parallel along the second direction D2. In a specific implementation, the width of the back field sub-gate 30 may be set to be in a range of 40 μm to 150 μm.

In a specific implementation process, the back electrode 200 and the back electric field 300 are both disposed on the back surface of the passivation layer, and a groove (not shown) penetrating through the passivation layer is disposed on the back surface of the silicon wafer 100 for the back electric field 300 to electrically connect the back field sub-gate 30 to the back surface of the silicon wafer 100 directly.

In the specific implementation process, the back electrode 200 of the present invention can be configured as a silver electrode, which is printed and sintered by conductive silver paste; the back electric field 300 of the present invention is generally an aluminum back field, which is printed and sintered from conductive aluminum paste.

It is understood that the PERC double-sided battery of the present invention also has a front electrode disposed on the front surface of the silicon wafer 100, and is not further developed herein.

For better understanding of the technical effects of the PERC double-sided battery provided by the present invention, referring to fig. 6, in this embodiment, for the back field sub-grid 30 connected to the back electrode sub-grid 22, the current can flow into the back electrode sub-grid 22 through a short distance on the back field sub-grid 30, specifically, the farthest paths of the current transmitted from the back field sub-grid 30 to the back electrode sub-grid 22 are all less than half of the distance between two adjacent pad groups; further, the back electrode sub-gate 22 for connecting the back field sub-gate 30 with the pad 21 has a much smaller resistivity than the opposing back field sub-gate 30. Based on this, the utility model provides a back electrode 200 can effectively reduce the series resistance of PERC double-sided battery, and then improves PERC double-sided battery's battery efficiency.

Furthermore, because the utility model provides a back electrode 200 does not set up the main grid structure, and its consumption that can not increase corresponding conductive paste when back electrode 200 prints can also reduce the shading area at the battery back by a wide margin, and then improves PERC double-sided battery's two-sided rate.

Referring to fig. 7, which shows a structure of the PERC double-sided battery of the present invention different from the PERC double-sided battery shown in fig. 5, in this embodiment, the back electrode of the PERC double-sided battery includes ten sets of pads 200 spaced apart from each other along a first direction D1, and each set of pads includes five pads 21 spaced apart from each other along a second direction D2. It is understood that in other embodiments of the present invention, the number of the pad groups of the back electrode 200 and the number of the pads 21 of each pad group can be adjusted more as required.

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 practical implementation of the present invention, and they are not intended to limit the scope of the present invention, and all equivalent implementations or modifications that do not depart from the technical spirit of the present invention should be included in the scope of the present invention.

Claims

1. The utility model provides a PERC double-sided battery, includes the silicon chip, the silicon chip back is provided with the passivation layer, its characterized in that, PERC double-sided battery still have set up in the back electrode at the passivation layer back, the back electrode includes a plurality of pad groups that set up along first direction interval, each pad group includes a plurality of edges perpendicular to the pad of the second direction interval distribution of first direction use the pad is the origin, with along the straight line that first direction extended is the cross axle, with along the straight line that the second direction extended is in the coordinate system of axis of ordinates, the back electrode still includes four all to be connected to this the pad and towards the different electrode sublogs that extend of four quadrants.

2. The PERC double-sided battery of claim 1, wherein the pads of two adjacent pad groups are arranged in a one-to-one correspondence in the second direction, and in a quadrilateral region with two adjacent pads of one pad group and two corresponding pads of another adjacent pad group as vertices, four corresponding pads are connected with one electrode sub-grid located inside the quadrilateral region, and the four electrode sub-grids meet at one point.

3. The PERC double sided battery of claim 2, wherein said quadrilateral area has a rectangular shape, and a point in said quadrilateral area where said four electrode subgrids meet is a center point of said rectangular shape.

4. The PERC double sided battery of any of claims 1-3, wherein the width of said electrode subgrids has a tendency to taper away from the respective said pad.

5. The PERC bifacial battery of claim 4, wherein said electrode subgrids have a width in the range of 0.03mm to 0.1mm at an end thereof distal from said respective pads and a width in the range of 0.1mm to 1mm at an end thereof proximal to said respective pads.

6. The PERC double sided battery of any of claims 1-3, wherein said pads are circular or rectangular.

7. The PERC double sided battery of claim 6, wherein said pads are circular, said pads having a diameter in the range of 0.2mm to 4 mm.

8. The PERC double sided battery of claim 6, wherein said pads are rectangular, said pads having a width in said first direction in a range of 1mm to 4mm and a length in said second direction in a range of 2mm to 20 mm.

9. The PERC double sided battery of any of claims 1-3, further comprising a back electric field disposed on the back side of said passivation layer and electrically connecting said silicon wafer and said back electrode, said back electric field comprising a plurality of back field sub-gates spaced apart in parallel along said second direction.

10. A photovoltaic module comprising the PERC bifacial cell of any one of claims 1-9.