Master grid back contact cell and photovoltaic module

Abstract

The utility model discloses a kind of main gridless back contact battery and photovoltaic module, main gridless back contact battery includes: cell piece, secondary grid line and reinforcing structure, secondary grid line is set to the back of cell piece, secondary grid line extends along first direction and is spaced distribution in second direction, reinforcing structure is set to at least one secondary grid line and is used to be connected with corresponding electrical connector, the minimum size of reinforcing structure in second direction is greater than the size of corresponding secondary grid line in second direction;Wherein, reinforcing structure is provided with waste material capture area extending along first direction, the maximum size of waste material capture area in second direction is L1, the size of waste material capture area along first direction is L2, L1 and L2 satisfy relationship formula: 0.09mm≤L1≤0.2mm, 0.4mm≤L2≤0.8mm. Such setting can reduce the residual rate of waste material, and improve the welding quality of other components in main gridless back contact battery, and then the efficiency of main gridless back contact battery can be improved, and reliability.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, and in particular to a gridless back contact cell and photovoltaic module. Background Technology

[0002] With the rapid development and technological upgrading of the photovoltaic industry, back-contact batteries, with their advantages such as high conversion efficiency, are expected to become one of the mainstream battery technologies in the future.

[0003] Currently, after cutting and printing solder paste on the module end of the grid-less back contact cell, solder dross will appear. Due to the uncontrolled solder diffusion problem in the design of grid-less back contact cells, the residual solder dross rate will be too high, which will lead to a decrease in the electrical performance, reduced reliability and poor welding quality of the grid-less back contact cell. Utility Model Content

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one objective of the present invention is to provide a gridless back-contact battery, which can reduce the residual rate of waste materials, ensure electrical performance, improve reliability, and enhance welding quality.

[0005] This utility model further proposes a photovoltaic module.

[0006] According to the present invention, a gridless back-contact battery includes: a battery cell, sub-grid lines, and a reinforcing structure. The sub-grid lines are disposed on the back side of the battery cell, extending along a first direction and spaced apart in a second direction. The reinforcing structure is disposed on at least one of the sub-grid lines and is used to connect with a corresponding electrical connector. The minimum dimension of the reinforcing structure in the second direction is greater than the dimension of the corresponding sub-grid line in the second direction. The reinforcing structure includes a waste collection area extending along the first direction. The maximum dimension of the waste collection area in the second direction is L1, and the dimension of the waste collection area along the first direction is L2. L1 and L2 satisfy the following relationships: 0.09mm ≤ L1 ≤ 0.2mm, 0.4mm ≤ L2 ≤ 0.8mm.

[0007] According to the present invention, a gridless back contact battery is provided with a reinforcing structure on the sub-grid line. The reinforcing structure is larger than the sub-grid line in the second direction, and a waste capture area is provided in the reinforcing structure. The size of the waste capture area is guaranteed. This arrangement can ensure the electrical performance of the gridless back contact battery, and the waste capture area can absorb waste, thereby reducing the waste residue rate and improving the welding quality of other components in the gridless back contact battery. In this way, the efficiency and reliability of the gridless back contact battery can be improved.

[0008] In some examples of this invention, the size of the waste capture area in the second direction decreases from its middle portion to both ends, and the size of the middle portion of the waste capture area in the second direction is the maximum size of the waste capture area in the second direction.

[0009] In some examples of this utility model, the waste capture area includes sub-capture areas on both sides of a center line extending along the second direction in the middle of the waste capture area. The two sub-capture areas are constructed in a trapezoidal shape and are symmetrically arranged about the center line extending along the second direction in the middle of the waste capture area.

[0010] In some examples of this utility model, the dimension of the end of the waste capture area in the second direction is L3, and L3 satisfies the relationship: 0.05mm≤L3≤0.08mm.

[0011] In some examples of this utility model, the waste capture member further includes: a transition zone and a separation zone. The transition zone is respectively disposed at both ends of the waste capture zone in the first direction. The size of the transition zone in the second direction increases along the first direction away from the waste capture zone. The separation zone is respectively disposed at one end of the transition zone in the first direction away from the waste capture zone. The size of the separation zone in the second direction is greater than the size of the transition zone in the second direction.

[0012] In some examples of this utility model, the transition area is constructed as a trapezoid, and the dividing area is constructed as a rectangle with its long side extending along the second direction.

[0013] In some examples of this utility model, the dimension of the transition zone in the second direction at the end near the waste capture zone is L4 and the dimension in the second direction at the end away from the waste capture zone is L5, and the dimension of the transition zone in the first direction is L6. L4, L5 and L6 satisfy the following relationships: 0.005mm≤L4≤0.2mm, 0.05mm≤L5≤0.1mm, 0.02mm≤L6≤0.1mm; and / or the dimension of the separation zone in the second direction is L7 and the dimension in the first direction is L8, and the dimensions of L7 and L8 satisfy the following relationships: 0.15mm≤L7≤0.3mm, 0.01mm≤L8≤0.02mm.

[0014] In some examples of this utility model, the reinforcing structure is symmetrically arranged about the center line extending along the second direction in the middle of the waste capture area; and / or the height of the reinforcing structure on the back of the battery cell is h, where h satisfies the relationship: h≥4um; and / or the plurality of sub-gates include positive and negative sub-gates staggered along the second direction, at least one positive sub-gate and at least one negative sub-gate are provided with the reinforcing structure, and the reinforcing structure of the positive sub-gate and the reinforcing structure of the negative sub-gate are staggered in the second direction.

[0015] In some examples of this utility model, the non-main grid back contact battery further includes: an edge collection grid, which is disposed at one end of the plurality of sub-grid lines in the first direction and electrically connected to the grid line of the corresponding polarity, the edge collection grid extends along the second direction, and the edge collection grid is provided with a defined marking point.

[0016] The photovoltaic module according to this utility model includes: the gridless back contact cell and the electrical connector described above, wherein the electrical connector is disposed on the back side of the cell and connected to the corresponding reinforcing structure.

[0017] Compared with the prior art, this utility model adopts a reinforcing structure on the sub-grid line. The reinforcing structure is larger than the sub-grid line in the second direction. Moreover, a waste capture area is set in the reinforcing structure, and the size of the waste capture area is guaranteed. This arrangement can ensure the electrical performance of the gridless back contact battery, and the waste capture area can absorb waste, thereby reducing the waste residue rate and improving the welding quality of other components in the gridless back contact battery. In this way, the efficiency and reliability of the gridless back contact battery can be improved.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0020] Figure 1 This is a schematic diagram of the structure of a gridless back contact battery according to an embodiment of the present invention;

[0021] Figure 2 This is a partial structural schematic diagram of a gridless back contact battery according to an embodiment of the present invention;

[0022] Figure 3 This is a structural diagram of the reinforced structure.

[0023] Figure label:

[0024] 100. Battery with no main grid back contact;

[0025] 10. Solar cell; 20. Sub-grid line; 21. Positive electrode sub-grid; 22. Negative electrode sub-grid; 30. Reinforcing structure; 31. Waste capture area; 32. Sub-capture area; 33. Transition area; 34. Separation area; 40. Edge collection grid; 41. Defining marker point. Detailed Implementation

[0026] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present invention are described in detail below.

[0027] The following is for reference. Figures 1-3 This invention describes a gridless back contact cell 100 according to an embodiment of the present invention, which is used in a photovoltaic module.

[0028] like Figures 1-3 As shown, the gridless back contact battery 100 according to this utility model includes: a battery cell 10, sub-grid lines 20, and a reinforcing structure 30. The sub-grid lines 20 are disposed on the back side of the battery cell 10, extend along a first direction, and are spaced apart in a second direction. The reinforcing structure 30 is disposed on at least one sub-grid line 20 and is used to connect with a corresponding electrical connector. The minimum dimension of the reinforcing structure 30 in the second direction is greater than the dimension of the corresponding sub-grid line 20 in the second direction. The reinforcing structure 30 is provided with a waste collection area 31 extending along the first direction. The maximum dimension of the waste collection area 31 in the second direction is L1, and the dimension of the waste collection area 31 along the first direction is L2. L1 and L2 satisfy the following relationship: 0.09mm≤L1≤0.2mm, 0.4mm≤L2≤0.8mm.

[0029] Understandably, the solar cell 10, sub-busbars 20, and reinforcing structure 30 constitute the main structure of the gridless back contact solar cell 100. Through its gridless design, the gridless back contact solar cell 100 achieves a lower wet weight (15mg) and an efficiency improvement of approximately 0.15%. The sub-busbars 20 extend on the back of the solar cell 10 in a first direction and are spaced apart in a second direction. The sub-busbars 20 collect the current generated by the photovoltaic effect and discharge this current to the solar cell 10. Multiple sub-busbars 20 can cover more of the solar cell 10 surface, thus efficiently collecting current and improving the light absorption efficiency of the gridless back contact solar cell 100 while ensuring reduced resistance loss.

[0030] The reinforcing structure 30 is disposed on the sub-grid line 20, and the electrical connectors are arranged correspondingly to the reinforcing structure 30. This facilitates the current conduction by the electrical connectors and the series or parallel connection of the battery cells 10. It can also reduce resistance loss. The dimension of the reinforcing structure 30 in the second direction is larger than that of the sub-grid line 20 in the second direction. This arrangement facilitates the corresponding arrangement of the reinforcing structure 30 and the electrical connectors. The reinforcing structure 30 can also be connected to the sub-grid line 20 adjacent in the first direction, thereby enhancing the current of the sub-grid line 20 and improving the efficiency of the gridless back contact battery 100.

[0031] In addition, a waste capture area 31 is provided in the reinforcing structure 30. The waste capture area 31 extends along the first direction and is centrally located in the reinforcing structure 30. This allows the waste generated during the welding of the electrical connectors and the sub-grid lines 20 to enter the waste capture area 31, thereby preventing the waste from accumulating too high on the battery cell 10, reducing the waste residue rate, and improving the welding quality of the gridless back contact battery 100.

[0032] Optionally, the maximum dimension of the waste capture area 31 along the second direction should be within a reasonable range. If the maximum dimension of the waste capture area 31 in the first direction is less than 0.09 mm, the area of ​​the waste capture area 31 will be too small to fully accommodate the waste generated during welding, resulting in waste overflow and intrusion into the sub-grid line 20, thereby affecting the conductivity of the sub-grid line 20. If the maximum dimension of the waste capture area 31 in the second direction is greater than 0.2 mm, the area of ​​the waste capture area 31 will be too large, thereby affecting the arrangement of the sub-grid line 20 and the efficiency of the gridless back contact battery 100. If the maximum dimension of the waste capture area 31 in the second direction is within a reasonable range, it can not only fully accommodate the waste, but also ensure the reasonable arrangement of the sub-grid line 20, thereby reducing the waste residue rate and improving the welding quality of other components in the gridless back contact battery 100, thereby improving the efficiency and reliability of the gridless back contact battery 100. For example, the maximum dimension of the waste capture zone 31 in the second direction is 0.1 mm, 0.15 mm, or 0.18 mm, and the specific value is selected according to the actual situation.

[0033] The dimensions of the waste capture area 31 in the first direction must be within a reasonable range. If the dimensions of the waste capture area 31 in the first direction are less than 0.4 mm, the area of ​​the waste capture area 31 will be too small to fully contain the waste generated during welding, resulting in waste overflow and intrusion into the sub-grid line 20, thereby affecting the conductivity of the sub-grid line 20. If the dimensions of the waste capture area 31 in the first direction are greater than 0.8 mm, the area of ​​the waste capture area 31 will be too large, thereby affecting the arrangement of the sub-grid line 20 and the efficiency of the gridless back contact battery 100. If the dimensions of the waste capture area 31 in the first direction are within a reasonable range, it can not only fully contain the waste, but also ensure the reasonable arrangement of the sub-grid line 20, thereby reducing the waste residue rate and improving the welding quality of other components in the gridless back contact battery 100, thereby improving the efficiency and reliability of the gridless back contact battery 100. For example, the maximum dimension of the waste capture zone 31 in the second direction is 0.5mm, 0.6mm, or 0.7mm, and the specific value is selected according to the actual situation.

[0034] Therefore, by providing a reinforcing structure 30 on the sub-grid line 20, the reinforcing structure 30 having a larger dimension in the second direction than the sub-grid line 20, and by providing a waste capture area 31 in the reinforcing structure 30 and ensuring the size of the waste capture area 31, the reinforcing structure 30 can ensure the electrical performance of the gridless back contact battery 100, and the waste capture area 31 can absorb waste, thereby reducing the waste residue rate and improving the welding quality of other components in the gridless back contact battery 100, thereby improving the efficiency and reliability of the gridless back contact battery 100.

[0035] In particular, such as Figure 3 As shown, the size of the waste capture zone 31 in the second direction decreases from the middle to both ends, and the size of the middle part of the waste capture zone 31 in the second direction is the maximum size of the waste capture zone 31 in the second direction.

[0036] It is understandable that the waste capture area 31 is located between two adjacent sub-grid lines 20 in the first direction. The waste capture area 31 forms the largest size in the second direction. On both sides of the largest size in the first direction, the size of the waste capture area 31 in the second direction decreases. That is, the size of the middle part of the waste capture area 31 in the second direction is the largest, and the size of the two sides of the middle part of the waste capture area 31 in the second direction gradually decreases. This can divide the waste capture area 31 into a triangle or trapezoid, which can not only accommodate waste in the waste capture area 31, but also save the area occupied by the waste capture area 31, thereby reducing the waste residue rate and improving the welding quality of other components in the gridless back contact battery 100.

[0037] Among them, such as Figure 3As shown, the waste capture zone 31 includes two sub-capture zones 32 located on either side of a center line extending in a second direction in the middle of the waste capture zone 31. The two sub-capture zones 32 are trapezoidal in shape and symmetrically arranged about the center line extending in the second direction in the middle of the waste capture zone 31.

[0038] In other words, two sub-capture areas 32 are spliced ​​together to form a waste capture area 31. The connection point of the two sub-capture areas 32 has the largest dimension in the second direction, and the dimensions of the two sub-capture areas 32 gradually decrease in the second direction as they move away from each other. This allows the two sub-capture areas 32 to form two trapezoids, with the lower bases of the trapezoids connected and the upper bases facing each other. The two sub-capture areas 32 form an axisymmetric shape along the lower base. This allows the waste capture area 31 to collect waste evenly, simplifies the process of the reinforcing structure 30, ensures uniform distribution of thermal stress, guarantees the space utilization of the reinforcing structure 30, and optimizes the electrical performance of the gridless back contact battery 100.

[0039] Optionally, such as Figure 3 As shown, the dimension of the end of the waste capture zone 31 in the second direction is L3, and L3 satisfies the relationship: 0.05mm≤L3≤0.08mm.

[0040] It is understandable that the dimension of the end of the waste capture area 31 in the second direction must be within a reasonable range. If the dimension of the end of the waste capture area 31 in the second direction is less than 0.05 mm, it will cause the two sub-capture areas 32 to form a triangle. It will also cause the area of ​​the waste capture area 31 to be too small, unable to completely contain the waste generated during welding, resulting in waste overflow and intrusion into the sub-gate line 20, thus affecting the conductivity of the sub-gate line 20. If the dimension of the end of the waste capture area 31 in the second direction is greater than 0.08 mm, it will cause the two sub-capture areas 32 to form a triangle. The trapezoidal shape of the waste capture area 32 is not obvious, which can lead to an excessively large area of ​​the waste capture area 31. This affects the arrangement of the sub-grid lines 20 and the efficiency of the gridless back contact battery 100. If the dimension of the end of the waste capture area 31 in the second direction is within a reasonable range, it can not only fully accommodate the waste but also ensure a reasonable arrangement of the sub-grid lines 20. This can reduce the residual waste rate and improve the welding quality of other components in the gridless back contact battery 100, thereby improving the efficiency and reliability of the gridless back contact battery 100. For example, the dimension of the end of the waste capture area 31 in the second direction can be 0.06mm, 0.07mm, or 0.08mm, with the specific value selected according to the actual situation.

[0041] In addition, such as Figure 3As shown, the waste capture device further includes a transition zone 33 and a partition zone 34. The transition zone 33 is respectively disposed at both ends of the waste capture zone 31 in the first direction. The size of the transition zone 33 in the second direction increases along the first direction away from the waste capture zone 31. The partition zone 34 is respectively disposed at one end of the transition zone 33 in the first direction away from the waste capture zone 31. The size of the partition zone 34 in the second direction is larger than the size of the transition zone 33 in the second direction.

[0042] In other words, the transition zone 33 is located on both sides of the waste capture zone 31 in the first direction, and the separation zone 34 is located on the side of the transition zone 33 away from the waste capture zone 31. Moreover, the transition zone 33 and the waste capture zone 31 are connected. This allows all the waste to enter the waste capture zone 31, and the waste that the waste capture zone 31 cannot hold can enter the transition zone 33, thus ensuring that the waste does not easily accumulate on the battery cell 10. The size of the transition zone 33 in the second direction gradually increases along the first direction away from the waste capture zone 31, and the side of the transition zone 33 away from the waste capture zone 31 has a certain size in the second direction, so that the transition zone 33 can form a trapezoid. The upper bottom of the waste capture zone 31 and the upper bottom of the transition zone 33 are connected, so that some waste can enter the transition zone 33. The size of the separation zone 34 in the second direction is larger than the size of the adjacent transition zone 33 in the second direction, so that the waste cannot flow out of the reinforcing structure 30, thereby preventing the waste from eroding the sub-grid line 20.

[0043] In particular, such as Figure 3 As shown, the transition zone 33 is trapezoidal, and the partition zone 34 is rectangular with its long side extending along the second direction. This arrangement allows waste that cannot be contained in the waste capture zone 31 to flow into the transition zone 33. The edge of the partition zone 34 is connected to the lower base of the trapezoid in the transition zone 33. The partition zone 34 can block the waste, preventing it from flowing out of the reinforcing structure 30. This prevents the waste from eroding the sub-grid line 20, thereby ensuring the efficiency and reliability of the gridless back contact battery 100.

[0044] Optionally, such as Figure 3 As shown, the dimension of the transition zone 33 in the second direction is L4 at the end near the waste capture zone 31 and L5 at the end away from the waste capture zone 31. The dimension of the transition zone 33 in the first direction is L6. L4, L5 and L6 satisfy the following relationship: 0.005mm≤L4≤0.2mm, 0.05mm≤L5≤0.1mm, 0.02mm≤L6≤0.1mm.

[0045] It is understandable that the dimension of the end of the transition zone 33 closest to the waste capture zone 31 in the second direction must be within a reasonable range. If the dimension of the end of the transition zone 33 closest to the waste capture zone 31 in the second direction is less than 0.005 mm, the waste overflowing from the waste capture zone 31 will not be able to effectively flow into the transition zone 33, resulting in waste overflow and intrusion into the sub-gate line 20, thereby affecting the conductivity of the sub-gate line 20. If the dimension of the end of the transition zone 33 closest to the waste capture zone 31 in the second direction is greater than 0.2 mm, the waste capture zone 33 will be unable to effectively flow into the transition zone 33, resulting in waste overflow and intrusion into the sub-gate line 20, thus affecting the conductivity of the sub-gate line 20. Most of the waste material from the transition zone 1 enters the transition zone 33, affecting the conductivity of the end of the sub-grid line 20 and consequently the efficiency of the gridless back contact battery 100. If the dimension of the end of the transition zone 33 near the waste capture zone 31 in the second direction is within a reasonable range, it can ensure that the waste overflowing from the waste capture zone 31 enters the transition zone 33, and also prevent the waste from corroding the sub-grid line 20. This reduces the residual waste rate and improves the welding quality of other components in the gridless back contact battery 100, thereby improving the efficiency and reliability of the gridless back contact battery 100. For example, the dimension of the end of the transition zone 33 near the waste capture zone 31 in the second direction is 0.01 mm, 0.0015 mm, or 0.0018 mm, with the specific value selected according to the actual situation.

[0046] The dimension of the end of the transition zone 33 furthest from the waste capture zone 31 in the second direction must be within a reasonable range. If the dimension of the end of the transition zone 33 furthest from the waste capture zone 31 in the second direction is less than 0.005 mm, the transition zone 33 will not be able to accommodate excess waste, resulting in waste erosion of the sub-busbars 20. If the dimension of the end of the transition zone 33 furthest from the waste capture zone 31 in the second direction is greater than 0.1 mm, the reinforcing structure 30 will occupy a large space, thus affecting the performance of the cell 10. If the dimension of the end of the transition zone 33 furthest from the waste capture zone 31 in the second direction is within a reasonable range, it can not only accommodate excess waste but also optimize the space occupied by the reinforcing structure 30, thereby optimizing the efficiency of the gridless cell. For example, the dimension of the end of the transition zone 33 furthest from the waste capture zone 31 in the second direction can be 0.01 mm, 0.05 mm, or 0.08 mm, with the specific value selected according to the actual situation.

[0047] The dimensions of the transition region 33 in the first direction must be within a reasonable range. If the dimensions of the transition region 33 in the first direction are less than 0.02 mm, the waste overflowing from the waste capture region 31 will not be able to flow effectively into the transition region 33, resulting in waste overflow and intrusion into the sub-grid line 20, thereby affecting the conductivity of the sub-grid line 20. If the dimensions of the transition region 33 in the first direction are greater than 0.1 mm, most of the waste from the waste capture region 31 will enter the transition region 33, thereby affecting the conductivity of the end of the sub-grid line 20, and thus affecting the efficiency of the gridless back contact battery 100. If the dimensions of the transition region 33 in the first direction are within a reasonable range, it can ensure that the waste overflowing from the waste capture region 31 enters the transition region 33, and also prevent the waste from corroding the sub-grid line 20, thereby reducing the waste residue rate and improving the welding quality of other components in the gridless back contact battery 100, thereby improving the efficiency and reliability of the gridless back contact battery 100. For example, the dimension of the end of the transition zone 33 near the waste capture zone 31 in the second direction is 0.025mm, 0.05mm, or 0.08mm, and the specific value is selected according to the actual situation.

[0048] The partition 34 has a dimension of L7 in the second direction and a dimension of L8 in the first direction. L7 and L8 satisfy the following relationship: 0.15mm≤L7≤0.3mm, 0.01mm≤L8≤0.02mm.

[0049] In other words, the size of the separator 34 in the second direction must be within a reasonable range. If the size of the separator 34 in the second direction is less than 0.15 mm, it will not be able to effectively block the isolation area, causing waste to overflow to the outside of the reinforcing structure 30. If the size of the separator 34 in the second direction is greater than 0.3 mm, it will occupy too much space and affect the arrangement of the sub-grid lines 20, thus affecting the efficiency of the gridless back contact battery 100. If the size of the separator 34 in the second direction is within a reasonable range, it can not only effectively block waste but also optimize the space occupied by the reinforcing structure 30, thereby improving the efficiency and reliability of the gridless back contact battery 100. For example, the size of the separator 34 in the second direction can be 0.18 mm, 0.2 mm, or 0.25 mm, with the specific value selected according to the actual situation.

[0050] The size of the separator 34 in the first direction must be within a reasonable range. If the size of the separator 34 in the first direction is less than 0.01 mm, it will not be able to effectively block the isolation area, causing waste to overflow to the outside of the reinforcing structure 30. If the size of the separator 34 in the first direction is greater than 0.02 mm, it will occupy too much space and affect the arrangement of the sub-grid lines 20, thus affecting the efficiency of the gridless back contact battery 100. If the size of the separator 34 in the first direction is within a reasonable range, it can not only effectively block waste but also optimize the space occupied by the reinforcing structure 30, thereby improving the efficiency and reliability of the gridless back contact battery 100. For example, the size of the separator 34 in the first direction can be 0.012 mm, 0.015 mm, or 0.018 mm, with the specific value selected according to the actual situation.

[0051] In addition, such as Figure 3 As shown, the reinforcing structure 30 is symmetrically arranged about the center line extending in the second direction about the middle of the waste capture area 31. This allows the waste generated when the electrical connector is welded to the sub-grid line 20 to enter the waste capture area 31, thereby preventing the waste from accumulating too high on the battery cell 10, reducing the waste residue rate, and improving the welding quality of the gridless back contact battery 100.

[0052] Optionally, the height of the reinforcing structure 30 on the back side of the cell 10 is h, where h satisfies the relationship: h ≥ 4 μm. If the height of the reinforcing structure 30 on the back side of the cell 10 is less than 4 μm, the space in the waste capture area 31 of the reinforcing structure 30 will be insufficient to accommodate the waste, resulting in the waste overflowing from the reinforcing structure 30 and affecting the performance of the cell 10. If the height of the reinforcing structure 30 on the back side of the cell 10 is greater than or equal to 4 μm, it can ensure that the waste enters the waste capture area 31, thereby reducing the waste residue rate and improving the welding quality of other components in the gridless back contact cell 100, thus improving the efficiency and reliability of the gridless back contact cell 100.

[0053] In addition, such as Figure 2 As shown, the plurality of sub-gates include positive sub-gates 21 and negative sub-gates 22 that are staggered along the second direction. At least one positive sub-gate 21 and at least one negative sub-gate 22 are provided with a reinforcing structure 30. The reinforcing structures 30 of the positive sub-gate 21 and the negative sub-gate 22 are staggered in the second direction.

[0054] It is understood that both the positive electrode sub-gate 21 and the negative electrode sub-gate 22 extend along the first direction, and the positive electrode sub-gate 21 and the negative electrode sub-gate 22 are arranged alternately in the second direction. A reinforcing structure 30 is provided between the positive electrode sub-gate 21 or the negative electrode sub-gate 22 in the first direction. The reinforcing structures 30 of the positive electrode sub-gate 21 and the negative electrode sub-gate 22 in the second direction are arranged alternately. This allows the waste generated when the electrical connector is welded to the positive electrode sub-gate 21 or the negative electrode sub-gate 22 to enter the waste capture area 31, thereby preventing the waste from accumulating too high on the battery cell 10, reducing the waste residue rate, and improving the welding quality of the gridless back contact battery 100.

[0055] In addition, such as Figure 2 As shown, the non-main grid back contact battery 100 further includes: an edge collection grid 40, which is disposed at one end of a plurality of sub-grid lines 20 in a first direction and electrically connected to the grid line of the corresponding polarity, the edge collection grid 40 extends along a second direction, and the edge collection grid 40 is provided with a defined marking point 41.

[0056] In other words, the edge collection grid 40 is located on one side of the end of the multiple sub-grid lines 20 in the first direction, and the edge collection grid 40 extends along the second direction. This allows the edge collection grid 40 to be electrically connected to the sub-grid lines 20 of the corresponding polarity, thereby forming a current loop between the sub-grid lines 20 and the edge collection grid 40. The edge collection grid 40 is provided with a defining mark point 41, which can mark the polarity. After the main grid-less back contact battery 100 is cut, the polarity of the battery cell 10 can be easily confirmed by the defining mark point 41, thereby simplifying the production and assembly process. For example, the defining mark point 41 is the origin with a diameter of 0.3mm-0.6mm. This setting does not affect the layout of the sub-grid lines 20 and also facilitates the confirmation of the polarity of the battery cell 10.

[0057] The photovoltaic module according to this utility model includes: a gridless back contact cell 100 and an electrical connector as described in the above embodiments. The electrical connector is disposed on the back side of the cell 10 and connected to a corresponding reinforcing structure 30. By providing a reinforcing structure 30 on the sub-busbar 20, the reinforcing structure 30 having a larger dimension in the second direction than the sub-busbar 20, and by providing a waste collection area 31 in the reinforcing structure 30 and ensuring the size of the waste collection area 31, the waste collection area 31 absorbs the weld slag or weld balls generated during the welding of the electrical connector to the sub-busbar 20. This arrangement ensures the electrical performance of the gridless back contact cell 100, thereby reducing the residual waste rate and improving the welding quality of other components in the gridless back contact cell 100, thus improving the efficiency and reliability of the gridless back contact cell 100.

[0058] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0059] In the description of this utility model, "first feature" and "second feature" may include one or more of the features. In the description of this utility model, "multiple" means two or more. In the description of this utility model, "above" or "below" the second feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. In the description of this utility model, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature.

[0060] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0061] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A gridless back contact battery (100), characterized in that, include: Battery cell (10); Sub-grid lines (20) are disposed on the back side of the battery cell (10), and the sub-grid lines (20) extend along a first direction and are spaced apart in a second direction; A reinforcing structure (30) is disposed on at least one of the sub-gate lines (20) and is used to connect to a corresponding electrical connector, wherein the minimum dimension of the reinforcing structure (30) in the second direction is greater than the dimension of the corresponding sub-gate line (20) in the second direction; The reinforcing structure (30) is provided with a waste capture area (31) extending along the first direction. The maximum dimension of the waste capture area (31) in the second direction is L1, and the dimension of the waste capture area (31) along the first direction is L2. L1 and L2 satisfy the following relationship: 0.09mm≤L1≤0.2mm, 0.4mm≤L2≤0.8mm.

2. The gridless back contact battery (100) according to claim 1, characterized in that, The size of the waste capture area (31) in the second direction decreases from its middle part to both ends, and the size of the middle part of the waste capture area (31) in the second direction is the maximum size of the waste capture area (31) in the second direction.

3. The gridless back contact battery (100) according to claim 2, characterized in that, The waste capture zone (31) includes two sub-capture zones (32) located on either side of a center line extending along the second direction in the middle of the waste capture zone (31). The two sub-capture zones (32) are constructed in a trapezoidal shape and are symmetrically arranged about the center line extending along the second direction in the middle of the waste capture zone (31).

4. The gridless back contact battery (100) according to claim 2, characterized in that, The dimension of the end of the waste capture zone (31) in the second direction is L3, and L3 satisfies the relationship: 0.05mm≤L3≤0.08mm.

5. The gridless back contact battery (100) according to claim 1, characterized in that, The waste capture device also includes: The transition zone (33) is respectively disposed at both ends of the waste capture zone (31) in the first direction, and the size of the transition zone (33) in the second direction increases in the direction away from the waste capture zone (31) along the first direction; The partition (34) is respectively disposed at the end of the transition zone (33) in the first direction away from the waste capture zone (31), and the size of the partition (34) in the second direction is larger than the size of the transition zone (33) in the second direction.

6. The gridless back contact battery (100) according to claim 5, characterized in that, The transition area (33) is constructed in a trapezoidal shape, and the dividing area (34) is constructed in a rectangle with its long side extending along the second direction.

7. The gridless back contact battery (100) according to claim 5, characterized in that, The dimension of the transition zone (33) in the second direction is L4 at the end closest to the waste capture zone (31) and L5 at the end furthest from the waste capture zone (31). The dimension of the transition zone (33) in the first direction is L6. L4, L5, and L6 satisfy the following relationships: 0.005mm ≤ L4 ≤ 0.2mm, 0.05mm ≤ L5 ≤ 0.1mm, 0.02mm ≤ L6 ≤ 0.1mm; and / or The partition (34) has a dimension of L7 in the second direction and a dimension of L8 in the first direction. L7 and L8 satisfy the following relationship: 0.15mm≤L7≤0.3mm, 0.01mm≤L8≤0.02mm.

8. The gridless back contact battery (100) according to any one of claims 1-7, characterized in that, The reinforcing structure (30) is symmetrically arranged about the centerline extending along the second direction in the middle of the waste capture zone (31); and / or The height of the reinforcing structure (30) on the back side of the battery cell (10) is h, where h satisfies the following relationship: h ≥ 4 μm; and / or The plurality of sub-gates include positive sub-gates (21) and negative sub-gates (22) that are staggered along the second direction, and at least one of the positive sub-gates (21) and at least one of the negative sub-gates (22) are provided with the reinforcing structure (30), and the reinforcing structure (30) of the positive sub-gate (21) and the reinforcing structure (30) of the negative sub-gate (22) are staggered in the second direction.

9. The gridless back contact battery (100) according to any one of claims 1-7, characterized in that, Also includes: An edge collection grid (40) is disposed at one end of a plurality of sub-grid lines (20) in the first direction and electrically connected to the grid lines of corresponding polarity. The edge collection grid (40) extends along the second direction and is provided with a defined marker point (41).

10. A photovoltaic module, characterized in that, include: The gridless back contact battery (100) according to any one of claims 1-9. An electrical connector is disposed on the back side of the battery cell (10) and connected to the corresponding reinforcing structure (30).

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