CN111370503A - Solar cell and solar cell module - Google Patents

Abstract

The invention discloses a solar cell and a solar cell module, wherein the solar cell is provided with a front surface and a back surface, the back surface is provided with a plurality of back electrodes, each back electrode comprises a main body connected with a welding strip, the main body extends lengthwise and is provided with a main body central line, each back electrode comprises a first end and a second end which are positioned on the main body central line, and each back electrode also comprises a flow guide part connected with the main body. Therefore, partial current can directly flow to the electrode main body through the flow guide part to assist the main grid to collect current together, so that the series resistance is reduced, and the efficiency of the battery piece is improved.

Description

Solar cells and solar cell modules

technical field

The invention relates to a solar cell sheet and a solar cell assembly, belonging to the technical field of solar power generation.

Background technique

Conventional solar cell backside silver electrodes (referred to as back electrodes) usually use segmented back electrodes, that is, each row of back electrodes is evenly divided into multiple segments, each segment has the same length, and the spacing between each segment is the same. Usually, there is a 0.5-2mm gap between the back electrode and the main grid, which is used to reduce the height difference at the junction and avoid poor welding and low ribbon tension during the module welding process. With the continuous improvement of backside efficiency requirements, the narrowing of the busbar is one of the optimization directions, but the gap between the back electrode and the busbar is bound to be narrowed on both sides, resulting in an increase in series resistance and affecting current collection.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a solar cell sheet which can improve the current collection efficiency.

In order to achieve the above purpose of the invention, the present invention provides a solar cell, which is provided with a front surface and a back surface, the back surface is provided with a plurality of back electrodes, and the back electrode includes a main body for connecting with a welding tape, and the main body is longitudinally long. Extending and having a main body centerline, the back electrode includes a first end and a second end located on the main body centerline, and the back electrode further includes a flow guide connected to the main body.

As a further improvement of an embodiment of the present invention, the air guide portion is disposed symmetrically with respect to the center line of the main body.

As a further improvement of an embodiment of the present invention, the air guide part includes a head air guide part connected to the first end, and the first end and the head air guide part form a U-shaped or V-shaped structure , the head guide part includes a pair of vertical guide arms connected with the first end, and a first blank of unprinted aluminum paste or silver paste is formed between the pair of vertical guide arms Area.

As a further improvement of an embodiment of the present invention, the head guide portion further includes a horizontal guide arm connected to the vertical guide arm, and the horizontal guide arm extends toward the centerline of the main body.

As a further improvement of an embodiment of the present invention, the guide portion includes a tail guide portion connected to the second end, and the second end and the tail guide portion form a U-shaped or V-shaped structure. It includes a pair of vertical guide arms parallel to the center line of the main body, and a second blank area of unprinted aluminum paste or silver paste is also formed between the two vertical guide arms, and the second blank area The area of is smaller than the area of the first blank area.

As a further improvement of an embodiment of the present invention, the back surface is further provided with a plurality of mutually parallel main grids and a plurality of sub grid lines connected to the main grid. The back electrodes are arranged on the main grid and are evenly distributed. The arrangement directions of the two adjacent back electrodes are opposite.

As a further improvement of an embodiment of the present invention, the head of the back electrode adjacent to the edge of the solar cell sheet is disposed toward the edge of the solar cell sheet.

As a further improvement of an embodiment of the present invention, the air guide portion includes a head air guide portion connected to the first end, a tail air guide portion connected to the second end, and the head air guide portion is different from the shape of the tail deflector.

As a further improvement of an embodiment of the present invention, the main body includes a plurality of first main body parts and second main body parts that are connected at intervals in sequence, and the air guide parts are arranged on both sides of the first main body part and are serrated shape, the width of the second main body portion is uniform and constant.

Compared with the prior art, the present invention has the beneficial effect that part of the current can flow directly to the electrode body through the current guide, assisting the main grid to collect current together, thereby reducing the series resistance and improving the efficiency of the cell.

Another object of the present invention is to provide a solar cell module including any one of the above-mentioned solar cell sheets.

Compared with the prior art, the beneficial effect of the present invention is that since the efficiency of the above-mentioned cell sheet is improved, the efficiency of the solar cell module of the present invention is also improved.

Description of drawings

FIG. 1 is a partial front view of the back side of the battery sheet provided by the first specific embodiment of the present invention;

Fig. 2 is the front view of the back electrode of the battery sheet shown in Fig. 1;

Fig. 3 is a partial enlarged view of the battery sheet shown in Fig. 1;

FIG. 4 is a partial enlarged view of the battery sheet provided by the second specific embodiment of the present invention.

Hereinafter, some specific embodiments of the present invention will be described in detail by way of example and not limitation with reference to the accompanying drawings. The same or similar parts or parts are designated by the same reference numerals in the figures. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. For example, some dimensions of structures or parts may be appropriately exaggerated relative to other structures or parts for the convenience of illustration. Therefore, the accompanying drawings are only used to illustrate the present invention. The basic structure of the subject of the application.

Detailed ways

The present invention will be described in detail below with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and structural, method, or functional changes made by those skilled in the art according to these embodiments are all included in the protection scope of the present invention.

It should be understood that, in the description of the present invention, the terms "upper", "lower", "left" and "right" refer to the positions corresponding to the battery sheet and the back electrode shown in the accompanying drawings. These terms indicating orientation or positional relationship, including but not limited to "upper", "lower", "left" and "right", are only for the convenience of description, rather than indicating or implying that the referred device or element must have a specific orientation, so as to The specific orientation configuration and operation are therefore not to be construed as limitations of the present invention.

In addition, the terms "first", "second", etc. are used for descriptive purposes only, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may include the first and second features in direct contact, or may include the first and second features Not directly but through additional features between them.

1 to 3 show the battery sheet 200 provided by the first embodiment of the present invention.

Referring to FIG. 1 , a cell sheet 200 of a solar cell provided by an embodiment of the present invention, the back side of the cell sheet 200 includes a plurality of sub-grid lines 300 for collecting current, connected to the sub-grid lines 300 and used for collecting a plurality of sub-grid lines 300 The main grid 400 for current, a plurality of auxiliary grid lines 300 are arranged in parallel and spaced apart, and a plurality of main grids 400 are arranged in parallel and spaced apart. The back electrodes 100 are evenly spaced apart on the bus bar 400 .

A plurality of back electrodes 100 are connected by soldering ribbons 500, and the soldering ribbons 500 can be connected with another cell sheet 200 to form a solar cell assembly. Thus, the current collected by the auxiliary grid line 300 flows to the main grid 400 , the back electrode 100 , the welding ribbon 500 , another battery slice .

In this embodiment, the sub-grid lines 300 and the main grid 400 are made of aluminum paste by printing, which is low in cost, but has poor electrical conductivity. The back electrode 100 is printed with silver paste, and the back electrode 100 has better electrical conductivity and higher cost.

Referring to FIG. 1 and FIG. 2 , in this embodiment, preferably, the back electrode 100 includes a main body 120 connected to the welding tape 500 .

In order to ensure the welding tension and reduce the offset of the welding ribbon 500 during the welding process, the length and width of the main body 120 cannot be too small, but the increase in the length and width will inevitably increase the consumption of silver paste and increase the cost.

Preferably, in this embodiment, the main body 120 has a welding lift portion 122 that is first connected to the welding tape 500 during the welding process, and the width of the welding lift portion 122 is larger than that of other parts of the main body 120 .

That is to say, the back electrode 100 is widened at the position of the start-up portion 122 , and the other parts are relatively narrowed, so as to ensure the welding tension and reduce the offset of the welding ribbon 500 , it can also reduce the consumption of silver paste and reduce the power consumption of the cell 200 . cost.

In this embodiment, the main body 120 extends longitudinally, and the main body 120 includes a first end 131 and a second end 132 spaced apart in the extending direction, a first side and a second end 132 connecting the edges of the first end 131 and the second end 132 on both sides. two sides. That is to say, the main body 120 has four edges, which are the first end 131 , the second end 132 , the first side, and the second side, respectively.

In this embodiment, the kick-off portion 122 is close to the first end 131 of the main body 120 . Therefore, in this embodiment, the width of the first end 131 of the main body 120 is larger than the width of the second end 132 and also larger than the width of other parts of the main body 120 .

The body 120 has a body centerline X. The main body center line X is the center line in the longitudinal extension direction of the main body 120. The entire main body 120 is symmetrically designed relative to the main body center line X and has a regular structure, so that the current can be collected more evenly and the current collection efficiency can be improved.

In this embodiment, an even number of back electrodes 100 are provided on the bus bar 400, and two adjacent back electrodes 100 are symmetrically arranged with respect to a line perpendicular to the bus bar 400. In other words, two adjacent back electrodes 100 are symmetrically arranged relative to a line parallel to the sub-gate lines 300 . In this embodiment, two adjacent back electrodes 100 on the same bus bar 400 are arranged in opposite directions. That is, if the lift-off portion 122 of one back electrode 100 faces upward, the lift-off portion of the adjacent back electrode 100 faces downward, and vice versa. In this embodiment, for the back electrode 100 located at the first and last positions, the welding release portion 122 is closer to the edge of the solar cell.

In this way, regardless of whether the cell 200 is a whole piece or the whole cell 200 is cut into two halves along a line perpendicular to the main grid 400 (or a line parallel to the sub-grid line 300 ), the wider width of the start-up portion can be achieved. 122 is first in contact with the ribbon 500, thereby ensuring the weld pull and reducing the offset of the ribbon 500 during welding.

Please refer to FIG. 1 and FIG. 3 , the bus bar 400 has a first blank area 500 near the first end 131 of the body 120 of the back electrode 100 . The first blank area 500 is rectangular, and the width of the first blank area 500 and the first end 131 are equal. The bus bar 400 has a second blank area 600 near the second end 132 of the body 120 of the back electrode 100 . The second blank area 600 is rectangular, and the width of the second blank area 600 is equal to the width of the second end 132.

The blank area means that nothing is printed on the cell 200 at this position, but the printed busbar 400 and the back electrode 100 have a certain thickness, and the thickness of the busbar 400 is higher than that of the back electrode 100. When When the solder ribbon 500 is gradually pressed from the upper busbar 400 to the start-up portion 122 of the back electrode 100 near the first end 131 , the first blank area 500 allows the solder ribbon 500 to gradually descend from the thicker busbar 400 to Connecting with the thinner back electrode 100 , that is, the first blank area 500 reduces the height difference between the busbar 400 and the back electrode 100 , which can increase the contact between the solder ribbon 500 and the back electrode 100 and avoid the tension of the solder ribbon 500 Too large, improve the welding quality.

The second blank area 600 can also alleviate the height difference between the second end 132 of the back electrode 100 and the main grid 400 , increase the contact between the ribbon 500 and the back electrode 100 , prevent the ribbon 500 from pulling too much, and improve the welding quality. No longer.

The blank area can improve the welding quality, but it also brings a problem, that is, the position of the busbar 400 in the blank area is narrowed, and the current density at this position is high. The back electrode 100 made of silver is poor and hinders current transmission greatly.

In order to solve this problem, in this embodiment, preferably, the back electrode 100 further includes a guide portion 150 connected to the main body 120 .

Therefore, part of the current can flow directly to the electrodes through the current guide portion 150 , which assists the busbar 400 to collect current together, thereby reducing the series resistance and improving the efficiency of the cell 200 .

In this embodiment, the size of the air guide portion 150 is smaller than that of the main body 120 . Specifically, the length and width of the guide portion 150 are much smaller than the length and width of the main body 120 , so as to achieve the effect of assisting current collection at low cost.

Preferably, in this embodiment, the main body 120 is disposed symmetrically with respect to the center line X of the main body, and the air guide portion 150 is also disposed symmetrically with respect to the center line X of the main body.

The current guiding portion 150 is symmetrically disposed relative to the center line X of the main body, so that the back electrode 100 can collect current evenly, thereby improving the efficiency of the battery sheet 200 .

Preferably in this embodiment, the air guide portion 150 includes a head air guide portion 152 connected to the first end 131 of the main body 120 , a tail air guide portion 154 connected to the second end 132 of the main body 120 , and the head air guide portion 152 is different from the shape of the tail deflector 154 .

In this embodiment, the widths of the first blank area 500 and the second blank area 600 are not equal. Specifically, the width of the first blank area 500 is greater than the width of the second blank area 600. Since the two blank areas 500/600 have different influences on current collection, the shape of the head guide portion 152 is different from that of the tail guide. Different shapes of the portion 154 can meet different needs.

Preferably, in this embodiment, the head guide includes a vertical guide arm 156 connected to the first end 131 and a horizontal guide arm 158 connected to the vertical guide arm 156 .

"Vertical" in this embodiment refers to a direction parallel to the center line X of the main body, and "horizontal" refers to a direction perpendicular to "vertical".

The vertical guide arm 156 and the horizontal guide arm 158 can better assist the main body 120 to collect current, thereby improving the efficiency of the battery sheet 200 . In particular, in this embodiment, the width of the first blank area 500 is wider, the first blank area 500 has a greater impact on current collection, and the vertical guide arms 156 and the horizontal guide arms 158 can be better reduced. The effect of the wider first white space 500 on current collection.

As mentioned above, the air guide portion 150 is symmetrically arranged with respect to the center line X of the main body. Correspondingly, the head air guide portion 152 is also arranged symmetrically with respect to the center line X of the main body. In this embodiment, the number of the head air guide parts 152 is two, and the two head air guide parts 152 are symmetrically arranged relative to the center line X of the main body.

In this embodiment, preferably, the starting end of the horizontal guide arm 158 is connected to the end of the vertical guide arm 156 , and the horizontal guide arm 158 extends in a direction close to the center line X of the main body.

That is, the head air guide portion 152 on the right side of the main body center line X is approximately in the shape of the numeral "7". Not only does it not increase the width of the back electrode 100 , but it can also better assist in collecting current and improve the efficiency of the battery sheet 200 .

In other words, in this embodiment, the first end 131 and the head guide portion 152 form a U-shaped structure, and those skilled in the art can imagine that the first end 131 and the head guide portion 152 may form a V-shaped structure.

In this embodiment, two adjacent back electrodes 100 on the same bus bar 400 are arranged in opposite directions. That is, if the head guide portion 152 of one back electrode 100 faces upward, the head guide portion 152 of the adjacent back electrode 100 faces downward, and vice versa.

In this embodiment, for the back electrode 100 adjacent to the edge of the solar cell sheet 200 , the head guide portion 152 thereof is disposed toward the edge of the solar cell sheet 200 .

As mentioned above, the bus bar 400 has blank areas near the first end 131 and the second end 132 of the back electrode 100 . In this embodiment, preferably, the guide portion 150 extends along the edge of the blank area. Specifically, the head guide portion 152 extends along the edge of the first blank area 500 . The tail guide portion 154 extends along the edge of the second blank area 600 .

Since the blank area affects the current collection, the guide portion 150 extends along the edge of the blank area, which can improve the current collection to the greatest extent, thereby minimizing the influence of the blank area on the current collection.

In this embodiment, the first guide blank area is rectangular, the first end 131 of the back electrode 100 is close to the lower side of the first blank area 500 , and the vertical guide arms 156 of the two head guide parts 152 are respectively Close to both sides of the first blank area 500 , the horizontal guide arms 158 of the two head guide parts 152 are close to the upper side of the first blank area 500 . That is to say, the head guide portion 152 extends from the first end 131 to the upper side of the first blank area 500 along both sides of the first blank area 500 , and the upper center part of the first blank area 500 is directly Adjacent to the busbar 400 .

Preferably, in this embodiment, half of the length of the first blank area 500 is greater than the length of the horizontal guide arm 158. Therefore, the upper central portion of the first blank area 500 is adjacent to the main grid 400 instead of the horizontal guide arm 158 . That is to say, the two horizontal guide arms 158 do not cover all the upper edges of the first blank area 500 , so as to prevent the main body 120 of the back electrode 100 and the head guide portion 152 from enclosing all the edges of the first blank area 500 . Ultimately, avoiding the first blank area 500 cannot improve the welding quality.

Preferably, in this embodiment, the tail air guide portion 154 is parallel to the center line X of the main body.

The tail guide portion 154 can also assist in collecting current to improve the efficiency of the cell 200 . In this embodiment, since the width of the second blank area 600 is narrow, the main grid 400 is less affected by the second blank area 600 , the tail guide portion 154 is parallel to the center line X of the main body, and the tail guide portion 154 is only Extending along the two edges of the second blank area 600 , the extension length of the tail guide portion 154 is short, but it can also satisfy the function of auxiliary current collection, and the short extension length can also reduce the cost of the back electrode 100 . Therefore, the tail deflector 154 strikes a reasonable balance between assisting in collecting current and reducing cost.

In this embodiment, the first end 131 of the main body 120 has a first blank area 500, and the second end 132 has a second blank area. Correspondingly, the guide portion 150 includes a head guide portion 152 and a tail guide portion. Flow section 154 . Those skilled in the art can imagine that only one end of the main body 120 can be provided with a blank area and a corresponding diversion portion can be provided, and any solution that is the same or similar to this embodiment is covered by the protection scope of the present invention.

In this embodiment, the air guide portion 150 is provided integrally with the main body 120 . That is, in the production process, the guide portion 150 and the main body 120 are printed together, which is convenient to manufacture.

Please refer to FIG. 2 and FIG. 3 , in this embodiment, preferably, the main body 120 includes a plurality of first main body parts 161 and second main body parts 162 that are connected at intervals in sequence, and the area of the first main body part 161 is larger than that of the second main body part 162 .

In this embodiment, "sequentially spaced connection" means that the main body 120 includes the first main body part 161 , the second main body part 162 , the first main body part 161 , the second main body part 162 . . . The structure is regular and the consumption of silver paste is reduced, thereby reducing the cost.

The area of the first body portion 161 is larger than that of the second body portion 162 , which can reduce the area of the second body portion 162 , thereby reducing the consumption of silver paste for manufacturing the back electrode 100 and reducing the cost of the cell 200 .

In this embodiment, the length and width of the first body portion 161 are both greater than those of the second body portion 162 , so that the area of the first body portion 161 is larger than that of the second body portion 162 .

Preferably, in this embodiment, the area of each first main body portion 161 gradually decreases along the direction away from the first end 131 . Therefore, the consumption of silver paste for manufacturing the back electrode 100 can be reduced, and the cost of the battery sheet 200 can be reduced. Moreover, the area of each first main body portion 161 is "gradually" reduced, which can make the current collection more balanced and stable, and improve the efficiency of the cell 200 .

As mentioned above, the welding lift portion 122 is disposed close to the first end 131 of the main body 120 , and the width of the first end 131 is larger than that of other parts of the main body 120 , so as to ensure the welding quality and reduce the consumption of silver paste. In this embodiment, further, along the direction away from the first end 131 , that is, the direction away from the welding release portion 122 , the area of each first main body portion 161 is gradually reduced, which can ensure the welding quality to the greatest extent and reduce the consumption of silver paste at the same time. .

In this embodiment, the area of each of the first main body parts 161 is gradually reduced, but the shape of each of the first main body parts 161 is the same. The regular structure can collect current more evenly and improve the efficiency of the cell 200 .

In this embodiment, preferably, the edges on both sides of the first main body portion 161 are in a square wave shape, and the crests of the square wave form the guide portion 150 .

That is to say, the two edges of the first main body portion 161 are also provided with the guide portions 150 to assist in collecting current, thereby improving the efficiency of the cell 200 .

In this embodiment, preferably, the two sides of each first main body portion 161 are in a square wave shape, and in the direction away from the first end 131 or the welding portion 122 , the wave crest connecting line 172 of each wave is gradually approaching the main body center line X. straight line. It should be noted that the peak connection line 172 is not a line actually existing on the back electrode 100 , but a virtual line for better explaining the structure of the back electrode 100 of the present embodiment.

The crest connection line 172 of each wave is a straight line gradually approaching the center line X of the main body, so that the width of each first main body part 161 gradually decreases, which not only reduces the consumption of silver paste, but also makes the width of the first main body part 161 equal. When the current is reduced, the magnitude of the reduction is well controlled to avoid the sudden change of shape affecting the current collection, thereby improving the current collection efficiency and the efficiency of the cell 200 .

In this embodiment, preferably, the two sides of each first main body portion 161 are in a square wave shape, and the wave bottom connecting line 174 of each wave is gradually approaching the main body center line X in the direction away from the first end 131 or the welding part 122 . the straight line. It should be noted that the wave-bottom line 174 is not a line actually existing on the back electrode 100 , but a virtual line for better explaining the structure of the back electrode 100 of the present embodiment.

Similar to the effect that the wave crest connecting line 172 is a straight line gradually approaching the center line X of the main body, the wave bottom connecting line 174 of the square waves is a straight line gradually approaching the main body center line X, which not only reduces the consumption of silver paste, but also improves the cell 200 efficiency. No longer.

To sum up, in the present embodiment, in the direction away from the first end 131 or the start-up portion 122 , the wave crest connection 172 of each wave is a straight line gradually approaching the main body center line X, and the wave bottom connection 174 of each wave is A straight line gradually approaching the main body center line X, that is, the wave crest connecting line 172 and the wave bottom connecting line 174 are not parallel to the main body center line X, but have an included angle with the main body center line X, therefore, those skilled in the art It should be understood that the so-called "square wave" shape in this embodiment is not absolutely regular, and may be appropriately offset or deformed, and any solution that is the same or similar to this embodiment is covered by the protection scope of the present invention.

In this embodiment, the width of the second body portion 162 may be slightly larger than the width of the solder ribbon 500 , which can minimize the consumption of silver paste for manufacturing the back electrode 100 and reduce the cost of the cell 200 .

Preferably, in this embodiment, the edge connecting line of each second body portion 162 is parallel to the center line X of the body. Preferably, the area and shape of each second body portion 162 are the same. Preferably, the second body portion 162 is a rectangle that meets the minimum width requirement, which can reduce the consumption of silver paste for manufacturing the back electrode 100 and reduce the cost of the battery sheet 200 .

Preferably, in this embodiment, the main body 120 of the back electrode 100 is provided with a plurality of hollow parts 180 .

The hollow portion 180 can reduce the consumption of silver paste in the process of manufacturing the back electrode 100 , thereby reducing the cost of the battery sheet 200 .

Moreover, if there is no hollow portion 180 on the main body 120 of the back electrode 100, during the contact process between the solder ribbon 500 and the back electrode 100, the solder will spread to both sides along the entire length of the back electrode 100 after being melted, resulting in the loss of solder per unit length. The amount of spreading will be reduced, resulting in insufficient welding tension, which ultimately affects the reliability of the welding. The hollow portion 180 can roughen the surface of the main body 120 , thereby reducing the spreading of solder and improving the soldering force and reliability of soldering.

Preferably, in this embodiment, the hollow parts 180 are evenly spaced on the entire area of the main body 120 .

This can reduce the cost of the battery sheet 200 to the greatest extent, and improve the welding connection force and ensure the reliability of the welding.

Preferably, in this embodiment, the center-to-center distance between two adjacent hollow parts 180 is between 0.1 and 0.5 mm. It is preferably between 0.15 and 0.3 mm.

When the center-to-center distance is within this range, the cost of the cell 200 can be reduced to the greatest extent, and the welding connection force can be improved and the reliability of the welding can be ensured.

Preferably, in this embodiment, the shape of the hollow portion 180 is one of a circle, a triangle, a rectangle, and a polygon.

Therefore, the shape of the hollow portion 180 can be selected as required, thereby facilitating the manufacture of the electrode.

Preferably, in this embodiment, the hollow portion 180 is circular, and the diameter of the circular hollow portion 180 is between 0.03 mm and 0.2 mm.

Those skilled in the art can understand that the circular hollow portion 180 has no sharp corners, which can improve the efficiency of the cell 200 .

As mentioned above, the back electrode 100 further includes a guide portion 150 connected to the main body 120 . In this embodiment, preferably, the guide portion 150 is also provided with a hollow portion 180 .

The hollow portion 180 provided on the guide portion 150 can not only assist in collecting current, but also reduce the consumption of silver paste, thereby reducing the cost of the battery sheet 200 , which can kill two birds with one stone.

In this embodiment, the consumption of silver paste is reduced by disposing the hollow portion 180 on the main body 120 . In fact, this embodiment not only reduces the consumption of silver paste by disposing the hollow portion 180 on the main body 120, but as mentioned above, the main body 120 includes a plurality of first main body parts 161 and second main body parts 162 that are connected in sequence and spaced apart. The area of the portion 162 is smaller than that of the first main body portion 161, which can also reduce the consumption of silver paste; along the direction away from the first end 131, the area of each first main body portion 161 gradually decreases, which can also reduce the consumption of silver paste ; The edges on both sides of each first main body portion 161 are in the shape of a square wave, and the width of the wave bottom of the edge of the square wave is reduced relative to the width of the wave crest, which can also reduce the consumption of silver paste.

Therefore, the battery sheet 200 of this embodiment can greatly reduce the consumption of silver paste, thereby greatly reducing the cost of the battery sheet 200 .

It should be noted that this embodiment is described by taking the back electrode 100 of a PERC bifacial cell as an example, but the back electrode 100 of this embodiment is particularly suitable for a PERC bifacial cell except for the relevant features of the current guide portion 150 . Other features, including but not limited to the edge of the first body portion 161 being a square wave shape and the hollow portion 180 on the electrode, can also be used in single-sided cells. Therefore, the technical features other than the guide portion 150 can also be used for solar energy. Other electrodes of the battery sheet 200 are not limited to the back electrode 100 . Any solution that is the same as or similar to this embodiment is covered within the protection scope of the present invention.

FIG. 4 shows the battery sheet 202 and the back electrode 102 according to the second embodiment of the present invention.

The difference between the battery sheet 202 of this embodiment and the battery sheet 200 of the first embodiment will be mainly described below.

In this embodiment, the back electrode mounting portion 104 of the portion of the busbar 402 where the back electrode 102 is mounted is defined, and the width of the back electrode mounting portion 104 is larger than that of other portions of the busbar 402 .

Therefore, the portion of the busbar 402 where the back electrode 102 is not installed can be made narrower, thereby improving the cell efficiency.

It should be understood that although this specification is described in terms of embodiments, not every embodiment only includes an independent technical solution, and this description in the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole, and each The technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

The series of detailed descriptions listed above are only specific descriptions for the feasible embodiments of the present invention, and they are not used to limit the protection scope of the present invention. Changes should all be included within the protection scope of the present invention.

Claims (10)

1. The utility model provides a solar wafer, its is equipped with the front and the back, the back is equipped with a plurality of back electrodes, back electrode is including being used for the main part of being connected with the solder strip, main part lengthwise extension has the main part central line, back electrode is including being located first end and second end on the main part central line, its characterized in that: the back electrode further includes a flow guide portion connected to the body.

2. The solar cell sheet according to claim 1, wherein: the flow guide parts are symmetrically arranged relative to the central line of the main body.

3. The solar cell sheet according to claim 1, wherein: the water conservancy diversion portion include with the head water conservancy diversion portion that first end is connected, first end with head water conservancy diversion portion constitutes U type or V type structure, head water conservancy diversion portion include a pair of with the vertical water conservancy diversion arm that first end is connected, and be formed with the first whitewashed district that leaves of not printing aluminium thick liquid or silver thick liquid between this a pair of vertical water conservancy diversion arm.

4. The solar cell sheet according to claim 3, wherein: the head flow guide part further comprises a horizontal flow guide arm connected with the vertical flow guide arm, and the horizontal flow guide arm extends towards the center line of the main body.

5. The solar cell sheet according to claim 3, wherein: the water conservancy diversion portion include with the afterbody water conservancy diversion portion that the second end is connected, the second end with afterbody water conservancy diversion portion constitutes U type or V type structure, and it includes a pair of being on a parallel with the vertical water conservancy diversion arm of main part central line also is formed with the second of not printing aluminium thick liquid or silver thick liquid between this two vertical water conservancy diversion arms and leaves the white district, the area in second leaves the white district is less than the area in first area of leaving the white district.

6. The solar cell sheet according to claim 5, wherein: the back surface is also provided with a plurality of mutually parallel main grids and a plurality of auxiliary grid lines connected with the main grids, the back electrodes are arranged on the main grids and are uniformly distributed, and the arrangement directions of two adjacent back electrodes on the same main grid are opposite.

7. The solar cell sheet according to claim 5, wherein: and the head flow guide part of the back electrode adjacent to the edge of the solar cell piece faces the edge of the solar cell piece.

8. The solar cell sheet according to claim 1, wherein: the flow guide part comprises a head flow guide part connected with the first end and a tail flow guide part connected with the second end, and the shape of the head flow guide part is different from that of the tail flow guide part.

9. The solar cell sheet according to claim 1, wherein: the main part includes a plurality of first main part and the second main part of interval connection in order, the water conservancy diversion portion is located the both sides limit of first main part just is the cockscomb structure, the width of second main part is even unchangeable.

10. A solar cell module, characterized in that: comprising a solar cell sheet according to any one of claims 1 to 9.

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