Main-grid-free battery piece and main-grid-free battery piece assembly

Abstract

The utility model relates to the technical field of photovoltaic cells, and provides a main-grid-free battery piece and a main-grid-free battery piece assembly, the main-grid-free battery piece comprises a front face and a back face, the front face and the back face each comprise a non-connecting line area and two connecting line areas, and the two connecting line areas are arranged at the two ends of the main-grid-free battery piece; the non-connecting line area is arranged between the two connecting line areas; a plurality of parallel grid lines are arranged in the non-connecting line area and the two connecting line areas; the interval between the grid lines in the two connecting line areas is smaller than the interval between the grid lines in the non-connecting line area. The two ends of the battery piece are divided into the connecting line areas, the connecting line areas are provided with the grid lines with small intervals, the number of the grid lines in the areas can be increased, welding strips in the areas cannot share currents borne by the grid lines, therefore, more grid lines are arranged to share the pressure of the currents borne by the grid lines, the areas can be prevented from being short-circuited, and the service life of the battery piece is prolonged. And the current cannot flow through the area so as to cause shadow.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic cells, in particular to a busbar-free cell and a busbar-free cell module. BACKGROUND

[0002] The busbar-free cell technology, also known as 0BB (Zero Busbar) technology, is an important innovative technology in the photovoltaic industry. The core of this technology is to cancel the main grid in the traditional photovoltaic cell and use thinner solder strips to directly connect the fine grids to collect and export the current. On the one hand, it can greatly reduce the amount of silver paste used, and on the other hand, it can also increase the effective light area of the cell and improve the power generation efficiency of the photovoltaic module.

[0003] The cell produced by adopting the connection line screen cell technology has a strip-shaped shadow on the edge of the cell after the module is laminated and tested by PL. The proportion of the strip-shaped shadow is more than 10%. The proportion of the strip-shaped shadow on the cutting edge is much larger than that on the chamfered edge. The reason is that the number of fine grids on the front surface is more than that on the back surface, so the spacing of the fine grids on the front surface is smaller than that on the back surface. Therefore, the current collected by the fine grids in the area not contacted by the solder strip on the front surface is smaller than that collected by the fine grids in the area not contacted by the solder strip on the back surface. The current carried by the fine grids in the area not contacted by the solder strip on the chamfered edge is smaller than that carried by the fine grids in the area not contacted by the solder strip on the cutting edge. Therefore, the proportion of the strip-shaped shadow on the cutting edge is much larger than that on the chamfered edge. In the area not contacted by the solder strip, the solder strip cannot share the current, which causes the area to be short-circuited, and the current cannot flow through the area, resulting in a shadow.

[0004] It can be seen that the existing connection line screen cell fine grid design is unreasonable, which causes the strip-shaped shadow on the edge of the cell and a high defect rate. Practical new type content

[0005] In order to solve at least one of the above technical problems, the present application provides a busbar-free cell and a busbar-free cell module. The busbar-free cell increases the number of fine grids and reduces the spacing of the fine grids in the part between the two, improves the current carrying capacity of the area, and avoids the appearance of a shadow in the area not contacted by the solder strip.

[0006] Therefore, in a first aspect, the present application provides a busbar-free cell, which includes a front surface and a back surface. The front surface is provided with a non-connection line area and two connection line areas. The two connection line areas are arranged on both sides of the front surface, and the non-connection line area is arranged between the two connection line areas. The back surface is also provided with a non-connection line area and two connection line areas. The two connection line areas are arranged on both sides of the back surface, and the non-connection line area is arranged between the two connection line areas. A plurality of parallel grid lines are arranged in the non-connection line area and the two connection line areas of the front surface and the back surface. The spacing of the grid lines in the two connection line areas is smaller than the spacing of the grid lines in the non-connection line area.

[0007] The present embodiment divides the two ends of the battery piece into a connection line area, and the connection line area is provided with a small interval between the grid lines, which can increase the number of grid lines in this area. Since the solder strip in this area cannot share the current carried by the grid lines, a larger number of grid lines can share the current carrying pressure of each grid line, which can avoid short circuiting of this area, and the current cannot flow through this area, resulting in a shadow. It can also avoid the current carried by the fine grid in the non-contact area of the front solder strip being less than the current carried by the fine grid in the back cutting edge, resulting in a strip-shaped shadow in the cutting edge.

[0008] In combination with the above-mentioned main grid-free battery piece, the interval between any two adjacent grid lines in the connection line area is the same.

[0009] In the present embodiment, the same interval is provided between the grid lines in the connection line area, which can make the current collected by each grid line relatively balanced, so that the current carried by each grid line is basically the same. This can make the current be uniformly transmitted to multiple grid lines, relieve the pressure of the current carried by each grid line, and avoid short circuiting of a certain grid line due to excessive current carrying capacity.

[0010] In combination with the above-mentioned main grid-free battery piece, on the front surface, the grid lines provided in the connection line area are first grid lines, the grid lines provided in the non-connection line area are second grid lines, and the interval between the first grid lines and the second grid lines is larger than the interval between the first grid lines provided in the connection line area.

[0011] In the present embodiment, on the front surface of the battery piece, at the connection between the connection line area and the non-connection line area, the interval between the first grid line at the edge of the connection line area and the second grid line at the edge of the non-connection area is larger than the interval between the two adjacent first grid lines, which can ensure that the grid lines in the connection line area have a small interval, so that the current in the connection line area is uniformly transmitted to multiple grid lines, the pressure of the current carried by each grid line is relieved, and the grid lines in this area are avoided from being short-circuited to cause a shadow.

[0012] In combination with the above-mentioned main grid-free battery piece, the interval of the first grid line is 0.7mm±0.01mm.

[0013] In the present embodiment, as a preferred embodiment, the interval of the first grid line can be set to 0.7mm±0.01mm, so that the current collected by each grid line is relatively balanced, and the purpose of relieving the pressure of the current carried by each grid line is achieved.

[0014] In combination with the above-mentioned main grid-free battery piece, the interval of the second grid line is 1.14mm±0.01mm.

[0015] In the present embodiment, as a preferred embodiment, the interval of the second grid lines is 1.14 mm±0.01 mm, so that each grid line in the non-connection new area can work within the bearable range without increasing the process cost, and the cost is low and has a certain aesthetic appearance.

[0016] In combination with the above-mentioned mainless grid cell, on the back surface, the grid lines arranged in the connection line area are third grid lines, and the grid lines arranged in the non-connection line area are fourth grid lines, and the interval between the third grid lines and the fourth grid lines is larger than the interval of the third grid lines arranged in the connection line area.

[0017] In the present embodiment, on the back surface of the cell, the interval between the third grid line at the edge of the connection line area and the fourth grid line at the edge of the non-connection line area is larger than the interval between the adjacent two third grid lines, so that the interval of the grid lines in the connection line area is small, thereby achieving the purpose of uniformly transmitting the current in the connection line area to the plurality of grid lines, relieving the pressure of each grid line bearing the current, and further avoiding the grid lines in the area being short-circuited to cause shading.

[0018] In combination with the above-mentioned mainless grid cell, the interval of the third grid lines is 0.76 mm±0.01 mm.

[0019] In the present embodiment, as a preferred embodiment, the interval of the third grid lines can be set to 0.76 mm±0.01 mm, so that the current collected by each grid line is relatively balanced, and the purpose of relieving the pressure of each grid line bearing the current is achieved.

[0020] In combination with the above-mentioned mainless grid cell, the interval of the fourth grid lines is 1.36 mm±0.01 mm.

[0021] In the present embodiment, as a preferred embodiment, the interval of the fourth grid lines is 1.36 mm±0.01 mm, so that each grid line in the non-connection new area can work within the bearable range without increasing the process cost, and the cost is low and has a certain aesthetic appearance.

[0022] In combination with the above-mentioned mainless grid cell, 5 grid lines are arranged in each connection line area; 78 grid lines are arranged on the front surface, and 72 grid lines are arranged on the back surface.

[0023] In the present implementation, 5 grid lines are arranged in each connection line area, which can improve the current carrying capacity of the area, and make the connection line areas at both ends of the battery piece have the same carrying capacity, so as to achieve the consistency of the edge current distribution of the battery piece. As a preferred embodiment, 78 grid lines are arranged on the front surface of the battery piece, and 72 grid lines are arranged on the back surface of the battery piece, so that each grid line in the non-connection area can work in the carrying range without increasing the process cost, which is low in cost and has a certain aesthetic appearance.

[0024] In a second aspect, the present application provides a main grid-free battery piece assembly, comprising a plurality of main grid-free battery pieces as described above, and the plurality of main grid-free battery pieces are electrically connected through a welding strip.

[0025] The main grid-free battery piece provided by the present application has at least the following beneficial effects compared with the prior art: the two ends of the battery piece are divided into connection line areas, and the grid lines with small intervals arranged in the connection line areas can increase the number of grid lines in the area. Since the welding strip cannot share the current carried by the grid lines, arranging more grid lines can share the pressure of the current carried by each grid line, which can avoid the area being short-circuited and the current flowing through the area, thereby causing a shadow. It can also avoid the current carried by the fine grid in the non-contact area of the front welding strip being less than the current carried by the fine grid in the cutting edge of the back surface, which causes a strip-shaped shadow in the cutting edge. The technical problem of the prior art that the fine grid design of the battery piece is unreasonable, which causes a strip-shaped shadow in the edge of the battery piece and a high rejection rate, is solved.

[0026] Other features and advantages of the present application will be described in detail in the following specific embodiment part. BRIEF DESCRIPTION OF DRAWINGS

[0027] The drawings used in the embodiments or the prior art description are briefly introduced as follows.

[0028] Fig. 1 A structure schematic view of the front surface of a main grid-free battery piece provided by the present application is provided.

[0029] Fig. 2 Another structure schematic view of the front surface of a main grid-free battery piece provided by the present application is provided.

[0030] Fig. 3 Still another structure schematic view of the front surface of a main grid-free battery piece provided by the present application is provided.

[0031] In the drawings:

[0032] 100, connection line area; 101, first grid line; 102, third grid line;

[0033] 200, non-connection line area; 201, second grid line; 202, fourth grid line. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0035] In the description of this application, the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting this application.

[0036] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "install", "connect" and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, a conflicting connection or an integrated connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0037] In the description of this specification, specific features, structures, materials, or characteristics may be combined in a suitable manner in any one or more embodiments.

[0038] Electroluminescence testing (EL) applies voltage to a cell, causing electrons and holes within the cell to emit light when they recombine, thereby observing the cell's internal structure and performance. EL testing can visually reveal potential defects in components, such as cracks, debris, and poor solder joints. Photoluminescence testing (PL) occurs when a solar cell is exposed to laser light or intense light, causing electrons in the material to be excited to a higher energy state. When these electrons return from a high-energy state to a lower energy state, they release photons.

[0039] With existing cell-to-cell connections, stripe-shaped shadows appear along the cell edges in 10% of cases after module lamination. Various process-side measures have been unable to effectively address this anomaly. Furthermore, the same stripe-shaped shadows appear in all EL tests for all products using cell-to-cell connections. Repeated current flow testing of the same module results in a darkening of the corresponding locations on the PL imaging. Repeated current flow testing further damages the cell itself. This is caused by the impact of current flow, and testing with a welder, stacked layers, or a 90-degree angle can exacerbate this anomaly.

[0040] Why the cutting edge bar shadow ratio will be much larger than the chamfer edge, because the battery piece screen front grid line spacing is 1.17484mm, back grid line spacing is 1.27343mm; therefore, the front solder strip does not contact the area of the fine grid to collect current will be less than the back solder strip does not contact the area of the fine grid to collect current; the front chamfer edge because the grid line is dense, the solder strip cannot contact the area of the fine grid to carry the current, which is less than the back cutting edge of the fine grid to carry the current, so the cutting edge bar shadow ratio is much larger than the chamfer edge. When EL is powered on, the solder strip current is transmitted to the fine grid line, and the solder strip cannot contact the outermost fine grid line of the screen, and the solder strip cannot share part of the current, which causes the fine grid line in this area to be unable to carry the current of the battery piece, resulting in the appearance of shadow. Since the current carrying capacity of the fine grid and the solder strip is a constant value, the current in the area where the screen solder strip does not contact exceeds the carrying capacity of the fine grid in this area, which is short-circuited, and the current will not flow through this area, which will also cause the appearance of shadow.

[0041] Based on this, the embodiment of the application provides a main grid-free battery piece, the number of fine grids in the part between the two is increased and the fine grid spacing is reduced, the current carrying capacity of the area is improved, and the shadow in the area where the solder strip does not contact is avoided.

[0042] As shown in Figs. 1-3 The main grid-free battery piece includes a front surface and a back surface, and the front surface and the back surface each include: a non-connection line area 200 and two connection line areas 100, the two connection line areas 100 are arranged at two ends of the main grid-free battery piece, and the non-connection line area 200 is arranged between the two connection line areas 100; that is, the front surface is provided with one non-connection line area 200 and two connection line areas 100, the two connection line areas 100 are arranged at two sides of the front surface, and the non-connection line area 200 is arranged between the two connection line areas 100; the back surface is also provided with one non-connection line area 200 and two connection line areas 100, and the two connection line areas 100 are arranged at two sides of the back surface, and the non-connection line area 200 is arranged between the two connection line areas 100; a plurality of parallel grid lines are arranged in the non-connection line area 200 and the two connection line areas 100; the spacing of the grid lines in the two connection line areas 100 is smaller than the spacing of the grid lines in the non-connection line area 200.

[0043] The embodiment divides the two ends of the battery piece into connection line areas 100, the two connection line areas 100 are arranged in an up-down distribution, and the non-connection line area 200 is arranged between the two connection line areas 100. The grid lines in the connection line area 100 are arranged in parallel along the width direction of the area, and the grid lines in the non-connection line area 200 are arranged in parallel with the grid lines in the connection line area 100. In other words, a plurality of parallel grid lines are arranged in the non-connection line area 200 and the two connection line areas 100, and the grid lines are arranged in parallel from top to bottom. The width direction mentioned above is the direction from top to bottom.

[0044] The battery piece is provided with two connection line areas 100 and one non-connection line area 200. The two connection line areas 100 are arranged at two ends along the width direction of the battery piece, and the non-connection line area 200 is arranged between the two connection line areas 100, i.e., the non-connection line area 200 is arranged in the middle of the two connection line areas 100.

[0045] The battery piece is generally rectangular, and four chamfers can be arranged at four corners, or two chamfers can be arranged at two symmetrical corners. In the embodiment in which two chamfers are arranged, the other two corners are not processed and remain as right angles. In other embodiments, the four corners of the battery piece can also not be processed and remain as right angles.

[0046] In the above several embodiments, the connection line areas 100 are arranged at opposite ends of the battery piece, and the connection line areas 100 are rectangular areas. The areas of the connection line areas 100 can be set according to actual conditions.

[0047] In the embodiment in which the battery piece is provided with four chamfers, one of the connection line areas 100 extends in the opposite direction of the side line based on the two symmetrical chamfers and the side line connecting the two chamfers. The other connection line area 100 is arranged opposite to it and also extends in the opposite direction of the side line based on the two symmetrical chamfers and the side line connecting the two chamfers. In this embodiment, the areas of the two connection line areas 100 can be the same or different. The difference between the two connection line areas 100 with different areas is that the lengths of the respective extensions in the opposite direction of the side line are different. In this embodiment, the two connection line areas 100 with the same area are preferably arranged symmetrically at the ends of the battery piece.

[0048] The interval of the grid lines in the two connection line areas 100 is smaller than the interval of the grid lines in the non-connection line area 200. That is, dense grid lines are arranged at the two ends of the battery piece, and sparse grid lines are arranged in the middle part. The connection line areas 100 are provided with grid lines with small intervals, which can increase the number of grid lines in this area. Since the solder strip in this area cannot share the current carried by the grid lines, arranging more grid lines can share the current carrying pressure of each grid line, which can avoid short circuiting of this area, current flow through this area, and thus the appearance of shadows. It can also avoid the situation that the current carried by the fine grid lines in the area not contacted by the front solder strip is smaller than the current carried by the fine grid lines in the back cutting edge, which leads to the appearance of strip-shaped shadows in the cutting edge.

[0049] The front and back of the battery piece are provided with a connection line area 100 and a non-connection line area 200, the difference between the two is that the front of the battery piece is provided with a larger number of grid lines, and the back of the battery piece is provided with a smaller number of grid lines. But the position setting of the connection line area 100 and the non-connection line area 200 provided on the front and back of the battery piece is the same. Both include two connection line areas 100 and one non-connection line area 200, the two connection line areas 100 are provided at the opposite ends of the battery piece, and the non-connection line area 200 is provided between the two connection line areas 100. And the grid lines in the connection line area 100 and the grid lines in the non-connection line area 200 are also parallelly arranged, and the interval of the grid lines in the two connection line areas 100 is smaller than the interval of the grid lines in the non-connection line area 200. That is, the two ends of the battery piece are provided with dense grid lines, and the middle part is provided with relatively sparse grid lines.

[0050] Compared with the prior art, the two ends of the battery piece are divided into connection line areas 100, the connection line area 100 is provided with grid lines with smaller intervals, which can increase the number of grid lines in this area. Since the solder strip in this area cannot share the current carried by the grid lines, setting more number of grid lines can share the pressure of the current carried by each grid line, which can avoid the area being short-circuited, the current cannot flow through this area, and thus the shadow appears. It can also avoid the current carried by the fine grid in the non-contact area of the front solder strip being less than the current carried by the fine grid in the back cutting edge, resulting in strip-shaped shadow on the cutting edge. It can solve the technical problems of unreasonable design of the fine grid of the battery piece in the prior art, resulting in strip-shaped shadow on the edge of the battery piece and high defective rate.

[0051] In an embodiment, each connection line area 100 is provided with 5 grid lines.

[0052] In the embodiment, 5 grid lines are provided in each connection line area 100. On the one hand, providing 5 grid lines can increase the number of grid lines in the area and improve the current carrying capacity of the area. On the other hand, it can make the connection line areas 100 at both ends of the battery piece have the same carrying capacity, achieving uniformity of the current distribution on the edge of the battery piece.

[0053] It should be noted that the interval of the 5 grid lines is smaller than the interval of the grid lines in the non-connection line area 200, so that the density of the grid lines in the connection line area 100 is increased, so that more number of grid lines can share the pressure of the current carried by each grid line, avoiding the situation that the area is short-circuited and shadow appears.

[0054] In an embodiment, the interval of any two adjacent grid lines provided in the connection line area 100 is the same.

[0055] In the embodiment, the same interval is arranged between the grid lines in the connection line area 100, so that the current collected by each grid line is relatively balanced, and the current borne by each grid line is basically consistent, which can make the current be uniformly transmitted to the plurality of grid lines, relieve the pressure of the current borne by each grid line, and avoid that a certain grid line is short-circuited due to the excessive current borne by the grid line.

[0056] In an embodiment, on the front surface of the battery piece, the grid line arranged in the connection line area 100 is the first grid line 101, the grid line arranged in the non-connection line area 200 is the second grid line 201, and the interval between the first grid line 101 and the second grid line 201 is larger than the interval of the first grid line 101 arranged in the connection line area 100.

[0057] In the embodiment, on the front surface of the battery piece, the interval between the first grid line 101 at the edge of the connection line area 100 and the second grid line 201 at the edge of the non-connection line area is larger than the interval between the adjacent two first grid lines 101, so that the interval of the grid lines in the connection line area 100 is small, thereby achieving the purpose of uniformly transmitting the current in the connection line area 100 to the plurality of grid lines, relieving the pressure of the current borne by each grid line, and further avoiding that the grid line in the area is short-circuited to cause the shadow.

[0058] In an embodiment, the interval of the first grid line 101 is 0.7mm±0.01mm.

[0059] As a preferred embodiment, the interval of the first grid line 101 can be set to 0.7mm±0.01mm, so that the current collected by each grid line is relatively balanced, and the purpose of relieving the pressure of the current borne by each grid line is achieved.

[0060] In an embodiment, the interval of the second grid line 201 is 1.14mm±0.01mm.

[0061] The embodiment can realize that each grid line in the non-connection line area works within the bearable range without increasing the process cost, has low cost, and has certain aesthetic property. As a more preferred embodiment, the interval of the second grid line 201 can be set to 1.14288mm±0.01mm.

[0062] In an embodiment, on the back surface of the battery piece, the grid line arranged in the connection line area 100 is the third grid line 102, the grid line arranged in the non-connection line area 200 is the fourth grid line 202, and the interval between the third grid line 102 and the fourth grid line 202 is larger than the interval of the third grid line 102 arranged in the connection line area 100.

[0063] In the embodiment, the interval between the third grid line 102 at the edge of the connecting line area 100 and the fourth grid line 202 at the edge of the non-connecting line area at the junction of the connecting line area 100 and the non-connecting line area 200 is greater than the interval between two adjacent third grid lines 102, which can ensure that the interval between the grid lines of the connecting line area 100 is small, thereby achieving the purpose of uniform transmission of current to the plurality of grid lines in the connecting line area 100, relieving the pressure of each grid line to bear the current, and further avoiding the short circuit of the grid lines in the area to cause the shadow.

[0064] In an embodiment, the interval of the third grid line 102 is 0.76mm±0.01mm.

[0065] As a preferred embodiment, the interval of the third grid line 102 can be set to 0.76mm±0.01mm, so that the current collected by each grid line is relatively balanced, achieving the purpose of relieving the pressure of each grid line to bear the current.

[0066] In an embodiment, the interval of the fourth grid line 202 is 1.36mm±0.01mm.

[0067] As a more preferred embodiment, the interval of the fourth grid line 202 can be set to 1.36025mm±0.01mm.

[0068] In an embodiment, the front side of the battery piece is provided with 78 grid lines, and the back side of the battery piece is provided with 72 grid lines.

[0069] As a preferred embodiment, the front side of the battery piece is provided with 78 grid lines, and the back side of the battery piece is provided with 72 grid lines, which can achieve the working of each grid line in the non-connecting line area within the bearable range without increasing the process cost, low cost and certain aesthetic appearance.

[0070] In addition, the application also provides a main grid-free battery piece assembly composed of a plurality of the above-mentioned main grid-free battery pieces, and the grid lines on the plurality of main grid-free battery pieces are all parallelly arranged.

[0071] The four edges of the battery piece can be connected to other battery pieces, so that the number of battery pieces in the battery piece assembly can be set according to the layout area. The power generation efficiency of the battery piece assembly can be improved.

[0072] The structure of the main grid-free battery piece in the embodiment is described above, and will not be described again.

[0073] The battery piece used by the mainless grid battery piece assembly provided by the embodiments of the present application divides two ends of the battery piece into a connection line area, the grid lines with small intervals in the connection line area can increase the number of grid lines in the area, since the solder strip in the area cannot share the current carried by the grid lines, therefore, setting more number of grid lines can share the pressure of current carried by each grid line, which can avoid the area from being short-circuited, the current cannot flow through the area, thus causing the appearance of a shadow. It can also avoid the current carried by the fine grid in the area not contacted by the front solder strip being less than the current carried by the fine grid in the back cutting edge, causing the cutting edge to appear a strip-shaped shadow. It can solve the technical problem that the fine grid design of the battery piece is unreasonable in the prior art, causing the edge of the battery piece to appear a strip-shaped shadow, and the high defect rate.

[0074] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A cell without a main grid, characterized in that, The front surface is provided with a non-connection line area and two connection line areas arranged on both sides of the front surface, and the non-connection line area is arranged between the two connection line areas; the back surface is also provided with the non-connection line area and the two connection line areas, and the two connection line areas are arranged on both sides of the back surface, and the non-connection line area is arranged between the two connection line areas; A plurality of parallel grid lines are arranged in the non-connection line area and the two connection line areas of the front surface and the back surface. The interval of the grid lines in the two connection line areas is smaller than the interval of the grid lines in the non-connection line area.

2. The cell without main grid according to claim 1, characterized in that, The interval of any two adjacent grid lines arranged in the connection line area is the same.

3. The busbar-less solar cell according to claim 2, characterized in that: On the front surface, the grid lines arranged in the connection line area are first grid lines, the grid lines arranged in the non-connection line area are second grid lines, and the interval between the first grid lines and the second grid lines is larger than the interval of the first grid lines arranged in the connection line area.

4. The cell as claimed in claim 3, wherein, The interval of the first grid lines is 0.7 mm±0.01 mm.

5. The cell without main grid according to claim 3 or 4, characterized in that, The interval of the second grid lines is 1.14 mm±0.01 mm.

6. The cell as claimed in claim 3, wherein On the back surface, the grid lines arranged in the connection line area are third grid lines, the grid lines arranged in the non-connection line area are fourth grid lines, and the interval between the third grid lines and the fourth grid lines is larger than the interval of the third grid lines arranged in the connection line area.

7. The no-finger cell sheet according to claim 6, wherein, The interval of the third grid lines is 0.76 mm±0.01 mm.

8. The cell without a main grid according to claim 6 or 7, characterized in that, The interval of the fourth grid lines is 1.36 mm±0.01 mm.

9. The no-lead grid cell of claim 1, wherein, Each of the connection line areas is provided with 5 grid lines; the front surface is provided with a total of 78 grid lines, and the back surface is provided with a total of 72 grid lines.

10. A no-lead cell assembly, comprising: The plurality of gridless battery pieces are electrically connected through a welding strip.

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