A solar cell, a battery module and a photovoltaic system

Abstract

The present invention is applicable to the field of photovoltaic technology, and provides a solar cell, a battery module and a photovoltaic system. The solar cell includes a silicon substrate and electrodes disposed on the silicon substrate. The electrodes include bus bars; the silicon substrate includes a doped layer; the bus bars include: connecting conductors and fine grid lines; the connecting conductors extend along a first direction, and the fine grid lines are disposed on the surface of the connecting conductors facing the silicon substrate; the connecting conductors are not in physical contact with the doped layer, and the fine grid lines are in physical contact with the doped layer. The fine grid lines collect carriers generated by the silicon substrate, reduce the carrier loss caused by the shielding of the connecting conductors, and the connecting conductors are used to transmit the collected carriers, with high transmission efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaics, and particularly relates to a solar cell, a battery module and a photovoltaic system. Background Art

[0002] As an efficient and clean energy conversion device, a solar cell is widely used in various photovoltaic power generation systems. A solar cell includes a silicon substrate and electrodes disposed on the silicon substrate. The electrodes are in ohmic contact with the silicon substrate and are responsible for effectively collecting electrons and holes (carriers) generated by the silicon material under sunlight irradiation, and then converting them into usable electrical energy.

[0003] In a traditional solar cell structure, in order to better collect the current from each electrode, a bus bar is added on the cell surface. The bus bar itself does not have the function of collecting carriers, but only serves as a current collection channel. When sunlight irradiates the surface of the solar cell, most carriers are generated in the area not blocked by the grid lines and are transmitted to the bus bar through the electrodes. To ensure the transmission efficiency of current collection, the width of the bus bar is relatively large, which often causes a certain degree of blockage to the cell surface, so that the carriers generated in the blocked area cannot be effectively collected, resulting in a reduction in the photoelectric conversion efficiency. Summary of the Invention

[0004] The present invention provides a solar cell, a battery module and a photovoltaic system, aiming to solve the problem that the traditional setting method affects the photoelectric conversion efficiency.

[0005] The present invention is implemented as follows. A solar cell includes a silicon substrate and electrodes disposed on the silicon substrate, and the electrodes include bus bars;

[0006] The silicon substrate includes a doped layer;

[0007] The bus bar includes: a connecting conductor and a fine grid line;

[0008] The connecting conductor extends along a first direction, and the fine grid line is disposed on the surface of the connecting conductor facing the silicon substrate;

[0009] The connecting conductor is not in physical contact with the doped layer, and the fine grid line is in physical contact with the doped layer.

[0010] Optionally, the fine grid line extends along the first direction.

[0011] Optionally, a plurality of fine grid lines are provided and are spaced apart along the first direction.

[0012] Optionally, along the first direction, the fine grid lines are collinear.

[0013] Optionally, along the first direction, at least part of the fine grid lines are staggered.

[0014] Optionally, along the first direction, the distances from at least one of the fine grid lines to the edges of the connecting conductors on both sides are equal.

[0015] Optionally, along the first direction, the distances from at least one of the fine grid lines to the edges of the connecting conductors on both sides are unequal.

[0016] Optionally, along the first direction, the distances between adjacent fine grid lines are equal.

[0017] Optionally, along the first direction, the distances between at least some adjacent fine grid lines are unequal.

[0018] Optionally, along the first direction, the total length of the fine grid lines is 10% - 90% of the total length of the connecting conductors.

[0019] Optionally, along the first direction, the total length of the fine grid lines is 50% - 90% of the total length of the connecting conductors.

[0020] Optionally, it further includes a current collecting conductor;

[0021] The current collecting conductor is arranged on the silicon substrate and extends along a second direction, and the second direction intersects with the first direction;

[0022] At least one end of the connecting conductor is connected to the current collecting conductor, and the current collecting conductor is not in physical contact with the doped layer.

[0023] Optionally, the current collecting conductor includes an edge bus bar, and the edge bus bar is arranged at the edge position of the silicon substrate.

[0024] Optionally, the silicon substrate has a light-facing surface and a backlight-facing surface arranged oppositely, and a first region and a second region are alternately arranged along the second direction on the backlight-facing surface, and the polarities of the first region and the second region are different;

[0025] The bus bar grid line includes a first bus bar grid line arranged in the first region and a second bus bar grid line arranged in the second region.

[0026] Optionally, the doped layer includes a first doped layer and a second doped layer, the first doped layer is arranged in the first region, and the second doped layer is arranged in the second region;

[0027] The fine grid lines of the first bus bar grid line are in physical contact with the first doped layer;

[0028] The fine grid lines of the second bus bar grid line are in physical contact with the second doped layer.

[0029] Optionally, the backlight surface has opposite first and second edges in a first direction, and the backlight surface has a plurality of first series connection regions and a plurality of second series connection regions. The first series connection regions include a first edge series connection region closest to the first edge, and there is no second series connection region between the first edge series connection region and the first edge;

[0030] The electrodes include a plurality of first electrodes and a plurality of second electrodes. All the first electrodes and all the second electrodes are arranged to cross the first series connection regions and the second series connection regions. The plurality of first electrodes include a plurality of first collection grid lines and at least one first bus grid line. The first collection grid lines are discontinuous at the first edge series connection region and continuous at the second series connection regions. The first bus grid line is continuous at both the first edge series connection region and the second series connection regions. The second electrodes are continuous at the first edge series connection region;

[0031] The edge bus line includes a first edge bus line, which is closer to the first edge than the first edge series connection region. The first edge bus line is electrically connected to at least part of the first collection grid lines and is electrically connected to the first bus grid line;

[0032] The solar cell further includes: a first auxiliary connection line disposed in the first edge series connection region. In a second direction, at least one side of the first bus grid line is provided with the first auxiliary connection line. The first auxiliary connection line connects at least two of the second electrodes located on the same side of the first bus grid line. Among them, at least two of the second electrodes connected to the first auxiliary connection line include the second electrodes adjacent to the first bus grid line.

[0033] Optionally, the first edge bus line is electrically connected to all the first collection grid lines; or

[0034] The first edge bus line is electrically connected to some of the first collection grid lines, and the number of the first collection grid lines not electrically connected to the first edge bus line is less than or equal to 4.

[0035] Optionally, the width of the first bus grid line is greater than the width of the part of the first collection grid lines outside the second series connection regions.

[0036] Optionally, the width of the first edge bus line is greater than the width of the part of the first collection grid lines outside the second series connection regions.

[0037] Optionally, the width of the first auxiliary connection line is greater than the width of the part of the first collection grid lines outside the second series connection regions.

[0038] Optionally, a plurality of the second series connection regions include a second edge series connection region closest to the first edge. The first electrode is continuous at the second edge series connection region, and the second electrode is discontinuous at the second edge series connection region. The solar cell further includes a second auxiliary connection line disposed in the second edge series connection region. In the second direction, the second auxiliary connection line connects the first bus bar and at least one of the first collection grid lines located on one side of the first bus bar.

[0039] Optionally, the width of the second auxiliary connection line is greater than the width of the portion of the first collection grid line located outside the second series connection region.

[0040] Optionally, a plurality of the second series connection regions include a third edge series connection region closest to the second edge, and there is no first series connection region between the third edge series connection region and the second edge;

[0041] A plurality of the second electrodes include a plurality of second collection grid lines and at least one second bus bar. The second collection grid lines are discontinuous at the third edge series connection region and continuous at the first series connection region. The second bus bar is continuous at the third edge series connection region and the first series connection region. The first electrode is continuous at the third edge series connection region;

[0042] The edge bus bar further includes a second edge bus bar, which is closer to the second edge than the third edge series connection region. The second edge bus bar is electrically connected to at least part of the second collection grid lines and electrically connected to the second bus bar;

[0043] The solar cell further includes: a third auxiliary connection line disposed in the third edge series connection region. In the second direction, the third auxiliary connection line is provided on at least one side of the second bus bar. The third auxiliary connection line connects at least two of the first electrodes located on the same side of the second bus bar. Among them, at least two of the first electrodes connected to the third auxiliary connection line include the first electrode adjacent to the second bus bar.

[0044] Optionally, the second edge bus bar is electrically connected to all of the second collection grid lines; or

[0045] The second edge bus bar is electrically connected to some of the second collection grid lines, and the number of the second collection grid lines not electrically connected to the second edge bus bar is less than or equal to 4.

[0046] Optionally, the width of the second bus bar is greater than the width of the portion of the second collection grid line located outside the first series connection region.

[0047] Optionally, the width of the second edge bus bar is greater than the width of the portion of the second collecting grid line outside the first series connection region.

[0048] Optionally, the width of the third auxiliary connection line is greater than the width of the portion of the second collecting grid line outside the first series connection region.

[0049] Optionally, several of the first series connection regions include a fourth edge series connection region closest to the second edge. The second electrode is continuous at the fourth edge series connection region, and the first electrode is discontinuous at the fourth edge series connection region. The solar cell further includes a fourth auxiliary connection line disposed in the fourth edge series connection region. In the second direction, the fourth auxiliary connection line connects at least one of the second bus bars and at least one of the second collecting grid lines on one side of the second bus bar.

[0050] Optionally, the width of the fourth auxiliary connection line is greater than the width of the portion of the second collecting grid line outside the first series connection region.

[0051] The present invention also provides a battery module including the above-mentioned solar cell.

[0052] The present invention also provides a photovoltaic system including the above-mentioned battery module.

[0053] The beneficial effects achieved by the present invention are as follows: By providing bus bars on the silicon substrate, the bus bars include connection conductors and fine grid lines. The fine grid lines are disposed on the surface of the connection conductor facing the silicon substrate. The connection conductor is not in physical contact with the doped layer, and the fine grid lines are in physical contact with the doped layer. The fine grid lines collect the carriers generated by the silicon substrate, reduce the carrier loss caused by the shielding of the connection conductor, improve the photoelectric conversion efficiency, and the connection conductor is used to transmit the collected carriers with high transmission efficiency. Description of the Drawings

[0054] Figure 1 is a schematic diagram of a partial structure of the backlight surface of the solar cell provided by the present invention;

[0055] Figure 2 is a partially enlarged schematic diagram of the backlight surface of the solar cell provided by the present invention;

[0056] Figure 3 is a schematic diagram of another partially enlarged structure of the backlight surface of the solar cell provided by the present invention;

[0057] Figure 4 is a schematic diagram of the structure of the bus bar provided by the present invention.

[0058] Description of the Reference Numerals

[0059] 100. Solar cell; 10. Silicon substrate; 101. First edge; 102. Second edge; 11. First series connection region; 111. First edge series connection region; 112. Fourth edge series connection region; 12. Second series connection region; 121. Second edge series connection region; 122. Third edge series connection region;

[0060] 20. First electrode; 21. First collection grid line; 22. First bus bar; 201. First welding section;

[0061] 30. Second electrode; 31. Second collection grid line; 32. Second bus bar; 301. Second welding section;

[0062] 40. First edge bus bar; 50. Second edge bus bar; 60. First auxiliary connection line; 70. Second auxiliary connection line; 80. Third auxiliary connection line; 90. Fourth auxiliary connection line;

[0063] 200. Bus bar; 210. Connection conductor; 220. Fine grid line. Detailed implementation mode

[0064] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the drawings and embodiments. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0065] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0066] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0067] In the description of the present invention, it should be noted that, unless otherwise clearly defined and limited, the terms "mounted", "connected" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, an electrical connection or a communication with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0068] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include that the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under" and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature.

[0069] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0070] In the present invention, by providing a busbar grid line on a silicon substrate, the busbar grid line includes a connecting conductor and a fine grid line. The fine grid line is provided on the surface of the connecting conductor facing the silicon substrate. The connecting conductor is not in physical contact with the doping layer, and the fine grid line is in physical contact with the doping layer. The fine grid line collects the carriers generated by the silicon substrate, reduces the carrier loss caused by the shielding of the connecting conductor, improves the photoelectric conversion efficiency, and the connecting conductor is used to transmit the collected carriers with high transmission efficiency.

[0071] Embodiment 1

[0072] As Figure 1 and Figure 4 shown, this embodiment provides a solar cell 100, including: a silicon substrate 10 and an electrode provided on the silicon substrate 10, and the electrode includes a busbar grid line 200;

[0073] The silicon substrate 10 includes a doped layer;

[0074] The busbar grid line 200 includes: a connecting conductor 210 and a fine grid line 220;

[0075] The connecting conductor 210 extends along a first direction, and the fine grid line 220 is disposed on the surface of the connecting conductor 210 facing the silicon substrate 10;

[0076] The connecting conductor 210 is not in physical contact with the doped layer, and the fine grid line 220 is in physical contact with the doped layer.

[0077] The silicon substrate 10 is the basis of the solar cell 100, and generally includes a silicon substrate and various functional layers stacked on the silicon substrate. That is, the silicon substrate 10 is the other part of the solar cell 100 excluding the metallization electrode pattern. The functional layers include a doped layer, and the doped layer further includes a p-type doped layer and an n-type doped layer. The p-type doped layer and the n-type doped layer can be disposed on one side or both sides of the silicon substrate to form a p-n junction and generate a photovoltaic effect. When light shines on the solar cell 100, photons can excite electrons to jump from the valence band to the conduction band, forming electron-hole pairs. These carriers are separated at the p-n junction due to the electric field effect, generating current.

[0078] An electrode is disposed on the silicon substrate 10, and the electrode is used to collect carriers (electrons or holes) generated by the silicon substrate. The electrode includes the busbar grid line 200. The busbar grid line 200 includes a connecting conductor 210 and a fine grid line 220, wherein the connecting conductor 210 is kept not in physical contact with the doped layer. Specifically, an insulating medium can be disposed at the non-physical contact position. The connecting conductor 210 is disposed on the silicon substrate 10, so the connecting conductor 210 has a surface facing the silicon substrate 10. The fine grid line 220 is disposed on the surface of the connecting conductor 210 facing the silicon substrate 10, and the fine grid line 220 is in physical contact with the doped layer to collect carriers generated by the silicon substrate 10. Since both the connecting conductor 210 and the fine grid line 220 are conductors and are electrically connected, the connecting conductor 210 can export the carriers collected by the fine grid line 220. The connecting conductor 210 extends along the first direction, and at both ends in the extending direction of the connecting conductor 210, different conductor structures can be connected.

[0079] It can be understood that physical contact means that direct material contact occurs between two or more objects when the surfaces of two or more objects are in direct contact. When physical contact occurs between conductors, the circuit is turned on. Non-physical contact means that there is no direct material contact between objects, and there is a gap between the objects, but it does not exclude the interaction between objects through a certain physical field or medium. For example, two spaced conductors are conducted through other dielectrics.

[0080] In this embodiment, by disposing a busbar 200 on a silicon substrate 10, the busbar 200 includes a connecting conductor 210 and a fine grid line 220. The fine grid line 220 is disposed on the surface of the connecting conductor 210 facing the silicon substrate 10. The connecting conductor 210 is not in physical contact with the doped layer, and the fine grid line 220 is in physical contact with the doped layer. The fine grid line 220 collects the carriers generated by the silicon substrate, reduces the carrier loss caused by the shielding of the connecting conductor 210, improves the photoelectric conversion efficiency, and the connecting conductor 210 is used to transmit the collected carriers with high transmission efficiency.

[0081] Embodiment Two

[0082] As Figure 4 shown, in some embodiments, the fine grid line 220 extends along a first direction.

[0083] Specifically, one fine grid line 220 can be disposed, or multiple fine grid lines 220 can be disposed. When multiple fine grid lines 220 are disposed, the multiple fine grid lines 220 can be arranged in parallel, the projections of the multiple fine grid lines 220 along the first direction can partially overlap, or the projections of the multiple fine grid lines 220 along the first direction can be spaced apart from each other.

[0084] The connecting conductor 210 extends along the first direction, and the extending direction of the fine grid line 220 is the same as that of the connecting conductor 210. This arrangement helps to uniformly transmit the current, reduces the local resistance inside the battery, and improves the overall current collection efficiency.

[0085] In some embodiments, along the first direction, the distances from at least one fine grid line 220 to the edges of the connecting conductors 210 on both sides are equal.

[0086] That is, along the first direction, at least one fine grid line 220 is disposed at the center position of the connecting conductor 210, then at least one fine grid line 220 overlaps with the center line position of the connecting conductor 210. At the center position, the distances from the fine grid line 220 to the edges of the connecting conductors 210 on both sides are equal, ensuring the uniform distribution of the fine grid line 220 on the connecting conductor 210 and avoiding local overheating. At the same time, disposing the fine grid line 220 at the center position of the connecting conductor 210 can simplify the design and manufacturing process and improve the production efficiency.

[0087] In some embodiments, along the first direction, the distances from at least one fine grid line 220 to the edges of the connecting conductors 210 on both sides are not equal.

[0088] That is, at least one fine grid line 220 is disposed at a position that does not overlap with the center line of the connecting conductor 210. The fine grid line 220 is disposed at a position deviating from the center line of the connecting conductor 210 and has a certain distance from the center line position. The distribution position of the fine grid line 220 can be optimized according to the light intensity and the requirements of the battery design, so that the fine grid line 220 can better collect the carriers.

[0089] Embodiment III

[0090] In some embodiments, a plurality of fine grid lines 220 are provided and arranged at intervals in the first direction.

[0091] More than two fine grid lines 220 are provided. Along the first direction, there is a certain distance between any two adjacent fine grid lines 220, that is, the projections of any two fine grid lines 220 in the first direction do not overlap. It can be understood that by establishing a coordinate axis x along the first direction, the projection of the fine grid line 220 on the coordinate axis x is the projection of the fine grid line 220 in the first direction.

[0092] The fine grid lines 220 are arranged at intervals in the first direction, which can well collect carriers along the extension direction of the first direction. At the interval positions, no fine grid lines 220 are provided. At the contact positions between the fine grid lines 220 and the connecting conductor 210, carriers will be captured and recombined, resulting in recombination loss. The fine grid lines 220 are arranged at intervals in the first direction, reducing the contact area between the fine grid lines 220 and the connecting conductor 210, which can reduce the carrier recombination loss caused by paste recombination. At the same time, no fine grid lines 220 need to be provided at the interval positions, which can also save the paste usage during manufacturing, thereby reducing the production cost of the solar cell 100.

[0093] In some embodiments, the fine grid lines 220 are collinear along the first direction.

[0094] That is, a plurality of fine grid lines 220 are distributed along the same straight line. The distances between any two adjacent fine grids can be all equal, can be partially equal, or can be all unequal, which is not limited herein. The collinear arrangement can centrally collect carriers and reduce the influence of dispersion on the battery performance. At the same time, the collinear fine grid lines 220 can simplify the design and manufacturing process and improve production efficiency.

[0095] In some embodiments, the fine grid lines 220 are staggered along the first direction.

[0096] A plurality of fine grid lines 220 are provided, and at least some of the fine grid lines 220 are not distributed along the same straight line. Specifically, all the fine grid lines 220 may not be distributed along the same straight line, that is, all the fine grid lines 220 are not collinear. For example, four fine grid lines 220 are provided, and the distance between any two fine grid lines 220 in the direction perpendicular to the first direction is not 0. It is also possible that some of the fine grid lines 220 are distributed along the same straight line and some are not. For example, four fine grid lines 220 are provided, and three of the fine grid lines 220 are distributed along the same straight line, and the distance between one fine grid line 220 and the three collinear fine grid lines 220 in the direction perpendicular to the first direction is not 0.

[0097] In some embodiments, along the first direction, the distances between adjacent fine grid lines 220 are equal.

[0098] The distance between the adjacent ends of two adjacent fine grid lines 220 is the distance between the two fine grid lines 220. The equal spacing ensures that the fine grid lines 220 are evenly distributed on the connecting conductor 210, improving the uniformity of carrier collection.

[0099] In some embodiments, along the first direction, the distances between at least some adjacent fine grid lines 220 are unequal.

[0100] It may be that the distances between all the fine grid lines 220 are not equal. For example, four fine grid lines 220 are provided, the distance between the first fine grid line 220 and the second fine grid line 220 is 50 μm, the distance between the second fine grid line 220 and the third fine grid line 220 is 60 μm, and the distance between the third fine grid line 220 and the fourth fine grid line 220 is 70 μm. Or it may be that the distances between some adjacent fine grid lines 220 are equal and the distances between some adjacent fine grid lines 220 are not equal. For example, the distance between the first fine grid line 220 and the second fine grid line 220 is 50 μm, the distance between the second fine grid line 220 and the third fine grid line 220 is 50 μm, and the distance between the third fine grid line 220 and the fourth fine grid line 220 is 70 μm.

[0101] The design of unequal spacing can optimize the distribution of the fine grid lines 220 according to the light intensity and the requirements of the battery design, so that the fine grid lines 220 can better collect carriers.

[0102] Embodiment 4

[0103] In some embodiments, along the first direction, the total length of the fine grid lines 220 is 10% - 90% of the total length of the connecting conductor 210.

[0104] The connecting conductor 210 extends along the first direction, and the total length of the connecting conductor 210 along the first direction is the distance between the two ends of the connecting conductor 210. The total length of the fine grid lines 220 along the first direction is the projected length of the fine grid lines 220 in the first direction. It can be understood that when multiple fine grid lines 220 are provided, if the projections of the multiple fine grid lines 220 in the first direction overlap, the length of the overlapping part is only calculated once.

[0105] The total length of the fine grid lines 220 is 10% to 90% of the total length of the connecting conductors 210. Specifically, the ratio of the total length of the fine grid lines 220 to the total length of the connecting conductors 210 can be 10%, 15%, 20%, 30%, 40%, 45%, 50%, 60%, 65%, 70%, 80%, 85%, 90%, or other ratios between 10% and 90%, which are not limited herein. Exemplarily, assuming the total length of the connecting conductors 210 is 10 mm, the total length of the fine grid lines 220 can be from 1 mm to 9 mm.

[0106] The total length of the fine grid lines 220 being 10% to 90% of the total length of the connecting conductors 210 ensures that the fine grid lines 220 can effectively conduct current while reducing the contact area between the fine grid lines 220 and the connecting conductors 210, which can reduce the carrier recombination loss caused by paste recombination. At the same time, it reduces the use of the fine grid line 220 paste and saves production costs. By reasonably designing the length of the fine grid lines 220, damage caused by excessive material accumulation can be avoided, and the long-term reliability of the battery can be improved.

[0107] In some embodiments, along the first direction, the total length of the fine grid lines 220 is 50% to 90% of the total length of the connecting conductors 210.

[0108] The total length of the fine grid lines 220 along the first direction is 50% to 90% of the total length of the connecting conductors 210. For example, assuming the total length of the connecting conductors 210 is 10 mm, the total length of the fine grid lines 220 can be from 5 mm to 9 mm. A higher ratio of the length of the fine grid lines 220 can maximize the carrier collection efficiency, improve the photoelectric conversion efficiency of the battery, and compared with full-length coverage, this method can reduce the amount of paste used and lower costs.

[0109] Embodiment Five

[0110] In some embodiments, the solar cell further includes a current collecting wire;

[0111] The current collecting wire is disposed on the silicon substrate 10 and extends along a second direction, and the second direction intersects with the first direction;

[0112] At least one end of the connecting conductor 210 is connected to the current collecting wire, and the current collecting wire is not in physical contact with the doped layer.

[0113] The connecting conductor 210 extends along a first direction, and the current collecting wire extends along a second direction which intersects the first direction. Specifically, the current collecting wire may extend along the longitudinal direction of the silicon substrate 10, and the connecting conductor 210 may extend along the transverse direction of the silicon substrate 10. That is, the first direction may be the longitudinal direction of the solar cell 100, and the second direction may be the transverse direction of the solar cell 100, and the two are perpendicular to each other. Of course, in other embodiments, the first direction and the second direction may also be other directions. For example, the two may be the diagonal directions of the silicon substrate 10 respectively, and specific limitations are not made here.

[0114] The current collecting wire is made of a conductive material and is not in physical contact with the doped layer. That is, spatially, the current collecting wire is spaced from the doped layer. Specifically, an insulating medium may be provided between the current collecting wire and the doped layer. It can be understood that since the fine grid line 220 is in physical contact with the doped layer and is electrically connected, and the connecting conductor 210 is connected to both the fine grid line 220 and the current collecting wire, the current collecting wire can be indirectly electrically connected to the doped layer through the busbar grid line 200.

[0115] The current collecting wire is used to transport carriers. At least one end of the connecting conductor 210 is connected to the current collecting wire, and the carriers collected by the fine grid line 220 are transported to the current collecting wire through the connecting conductor 210. The other end of the connecting conductor 210 may be connected to the current collecting wire or other conductive structures, such as Pad points, other connecting wires, etc., and no limitation is made here.

[0116] In some embodiments, the current collecting wire includes an edge busbar which is disposed at the edge position of the silicon substrate 10.

[0117] The edge busbar is disposed at the edge position of the silicon substrate 10. The "edge position" refers to the peripheral region of the silicon substrate 10, that is, the outermost part of the planar layout of the silicon substrate 10. Generally, one edge busbar can connect several electrodes (including the collecting grid line and the busbar grid line 200) to transport the current on the electrodes. It can be understood that since the edge busbar is used to transport current, the current transport efficiency is related to the cross-sectional area of the transport carrier. The larger the cross-sectional area, the smaller the resistance in the current transport process. Therefore, generally, the edge busbar has a relatively wide cross-sectional area. To avoid unevenness on the surface of the solar cell, the thickness of the edge busbar is relatively thin, so the edge busbar will have a relatively wide width.

[0118] If the edge busbar is disposed in the middle of the cell or other parts of the surface, it will cause occlusion of the effective light absorption area, reduce the generation of photo-generated carriers (i.e., photo-generated electrons and holes), and thus reduce the photoelectric conversion efficiency of the cell. Disposing the edge busbar at the edge position can minimize the occlusion of the effective light absorption area and improve the overall efficiency of the cell.

[0119] Embodiment Six

[0120] In some embodiments, the silicon substrate 10 has an optically facing surface and a backlight surface disposed opposite to each other. On the backlight surface, a first region and a second region are alternately arranged in a second direction, and the polarities of the first region and the second region are different.

[0121] The busbar 200 includes a first busbar 22 disposed in the first region and a second busbar 32 disposed in the second region.

[0122] The silicon substrate 10 has an optically facing surface and a backlight surface disposed opposite to each other. The optically facing surface generally refers to the side of the solar cell that receives sunlight radiation, and the backlight surface refers to the side of the solar cell that is away from sunlight radiation. The two surfaces are disposed opposite to each other.

[0123] Specifically, the silicon substrate 10 includes a silicon substrate and a doping layer. The doping layer is disposed on the silicon substrate. The doping layer includes a first doping layer and a second doping layer. The first doping layer is disposed in the first region, and the second doping layer is disposed in the second region. The first region and the second region are alternately arranged in a first direction, that is, on the silicon substrate, the first doping layer and the second doping layer are alternately arranged in the first direction. The first doping layer and the second doping layer have different polarities. It can be that the first doping layer is a P-type doping layer and the second doping layer is an N-type doping layer, or the first doping layer is an N-type doping layer and the second doping layer is a P-type doping layer. The first polar doping layer and the second polar doping layer form regions with different electrical characteristics, supporting the formation of a PN junction and the separation of carriers.

[0124] The busbar 200 includes a first busbar 22 and a second busbar 32. The first busbar 22 is disposed in the first region. The fine grid lines 220 on the first busbar 22 are in ohmic contact with the first doping layer, collecting the carriers generated in the corresponding first region, and transmitting the carriers generated in other connected first regions. The second busbar 32 is disposed in the second region. The fine grid lines 220 on the second busbar 32 are in ohmic contact with the second doping layer, collecting the carriers generated in the corresponding second region, and transmitting the carriers generated in other connected second regions.

[0125] It can be understood that the first region and the second region are alternately arranged, that is, the first region and the second region are disposed on the same piece of the silicon substrate 10. Usually, they are disposed on the backlight surface of the silicon substrate 10. The first electrode 20 and the second electrode 30 are respectively disposed corresponding to the first region and the second region, then the first electrode 20 and the second electrode 30 are disposed on the backlight surface of the silicon substrate 10. There is no electrode shielding on the optically facing surface of the silicon substrate 10. Therefore, the light absorption area can be maximally increased, the shadow loss can be reduced, and the photoelectric conversion efficiency of the battery can be significantly improved.

[0126] The first electrode 20 is disposed in the first region, in ohmic contact with the first doping layer, and collects carriers generated in the first region. The second electrode 30 is disposed in the second region, in ohmic contact with the second doping layer, and collects carriers generated in the second region. Alternately arranging the first region and the second region can ensure the uniform distribution of the fine gate lines 220 on the silicon substrate 10 and improve the uniformity of carrier collection.

[0127] Embodiment VII

[0128] As Figures 1 to 3 shown, in some embodiments, the backlight surface has opposite first edge 101 and second edge 102 in the first direction, the backlight surface has a plurality of first series connection regions 11 and a plurality of second series connection regions 12, the first series connection region 11 includes a first edge series connection region 111 closest to the first edge, and there is no second series connection region 12 between the first edge series connection region 111 and the first edge 101;

[0129] The electrodes include a plurality of first electrodes 20 and a plurality of second electrodes 30. All the first electrodes 20 and all the second electrodes 30 are arranged to cross the first series connection region 11 and the second series connection region 12. The plurality of first electrodes 20 include a plurality of first collection gate lines 21 and at least one first bus bar 22. The first collection gate lines 21 are discontinuous at the first edge series connection region 111 and continuous at the second series connection region 12. The first bus bar 22 is continuous at both the first edge series connection region 111 and the second series connection region 12. The second electrode 30 is continuous at the first edge series connection region 111;

[0130] The edge bus bar includes a first edge bus bar 40. The first edge bus bar 40 is closer to the first edge 101 than the first edge series connection region 111. The first edge bus bar 40 is electrically connected to at least part of the first collection gate lines 21 and electrically connected to the first bus bar 22;

[0131] The solar cell further includes: a first auxiliary connection line 60 disposed in the first edge series connection region 111. In the second direction, at least one side of the first bus bar 22 is provided with the first auxiliary connection line 60. The first auxiliary connection line 60 connects at least two second electrodes 30 located on the same side of the first bus bar 22. Among them, the at least two second electrodes 30 connected to the first auxiliary connection line 60 include the second electrode 30 adjacent to the first bus bar 22.

[0132] The solar cell 100 in the embodiment of the present application may include a silicon substrate 10, a plurality of first electrodes 20, a plurality of second electrodes 30, a first edge bus bar 40, a first insulating layer (not shown in the figure), and a first auxiliary connection line 60.

[0133] The silicon substrate 10 has opposite light-facing and backlight-facing surfaces. The backlight-facing surface of the silicon substrate 10 has opposite first and second edges 101 and 102 in a first direction, and the backlight-facing surface has a plurality of first connection areas 11 and a plurality of second connection areas 12. The first connection areas 11 and the second connection areas 12 are respectively used for arranging the positive electrode welding strips and the negative electrode welding strips. That is to say, one of the first connection areas 11 and the second connection areas 12 is the positive electrode connection area, and the other is the negative electrode welding area.

[0134] As Figure 1 and Figure 3 shown, in the first direction, the first connection areas 11 and the second connection areas 12 are arranged alternately. The plurality of first connection areas 11 includes a first edge connection area 111 closest to the first edge 101, and there is no second connection area 12 between the first edge connection area 111 and the first edge 101. That is to say, as Figure 1 shown, among the first connection areas 11 and the second connection areas 12, the connection area closest to the first edge 101 is the first connection area 11, and this first connection area 11 is represented as the first edge connection area 111, and there are no other connection areas between the first edge connection area 111 and the first edge 101.

[0135] As Figure 1 shown, a plurality of first electrodes 20 and a plurality of second electrodes 30 are arranged alternately along a second direction on the backlight-facing surface, and the second direction intersects the first direction. All the first electrodes 20 and all the second electrodes 30 are arranged in a crossed manner with the first connection areas 11 and the second connection areas 12. That is, the first connection areas 11 and the second connection areas 12 both extend along the second direction to intersect with the first electrodes 20 and the second electrodes 30.

[0136] In some embodiments, the first direction and the second direction can be respectively the longitudinal direction and the transverse direction of the solar cell 100, and the two are perpendicular to each other. For example, in Figure 1 the shown example, the first direction is the transverse direction of the solar cell 100, and the second direction is the longitudinal direction of the solar cell 100. Of course, in other embodiments, the first direction and the second direction can also be other directions, such as the two diagonal directions of the solar cell 100, and specific details are not limited here.

[0137] The plurality of first electrodes 20 may include a plurality of first collecting grid lines 21 and at least one first bus grid line 22. The first collecting grid lines 21 are discontinuous at the first edge connection area 111 and continuous at the second connection areas 12. The first bus grid line 22 is continuous at both the first edge connection area 111 and the second connection areas 12. The second electrodes 30 are continuous at the first edge connection area 111.

[0138] That is, the first electrode 20 includes at least two types of grid lines. One is the first collecting grid line 21, and the other is the first bus grid line 22. The first collecting grid line 21 is discontinuous at the first edge series connection area 111, while the first bus grid line 22 is continuous at the first edge series connection area 111, and the second electrode 30 is also continuous at the first edge series connection area 111. In the battery assembly, the solder tape in the first series connection area 11 (including the first edge series connection area 111) is used to connect to the second electrode 30 to achieve the bus output of the second electrode 30, and the solder tape in the second series connection area 12 is used to be welded to the first electrode 20 to achieve the bus output of the first electrode 20.

[0139] As Figure 2 shown, the first edge bus line 40 is closer to the first edge 101 than the first edge series connection area 111. The first edge bus line 40 is electrically connected to at least part of the first collecting grid line 21 and is electrically connected to the first bus grid line 22. Specifically, in order to avoid the battery from having hidden cracks caused by welding at the edge position of the first edge 101, the first edge bus line 40 is not used for welding. It is used to collect the current of the part of the first collecting grid line 21 between the first edge series connection area 111 and the first edge 101, and then is bused to the same-polarity solder tape in the second series connection area 12 adjacent to the first edge series connection area 111 (that is, Figure 1 and Figure 2 the leftmost second series connection area 12 in

[0140] The first auxiliary connection line 60 is arranged in the first edge series connection area 111. In the second direction, the first auxiliary connection line 60 is arranged on at least one side of the first bus grid line 22. The first auxiliary connection line 60 connects at least two second electrodes 30 located on the same side of the first bus grid line 22. Among them, as Figure 2 shown, in some embodiments, the at least two second electrodes 30 connected to the first auxiliary connection line 60 preferably include the second electrodes 30 adjacent to the first bus grid line 22 (that is, Figure 1 and Figure 2The second electrode 30 closest to the first busbar 22, that is, in some embodiments, the first auxiliary connection line 60 is preferably connected to the second electrode 30 closest to the first busbar 22, and the first auxiliary connection line 60 is also connected to at least one of the remaining second electrodes 30 on the same side as the second electrode 30. That is, the first auxiliary connection line 60 is preferably connected to at least the second electrode 30 adjacent to the first busbar 22 and at least one of the remaining second electrodes 30 on the same side.

[0141] In the solar cell 100, the first electrode 20 corresponds to the first doping layer one by one, the second electrode 30 corresponds to the second doping layer one by one, and one of the first doping layer and the second doping layer may be a P-type doping layer, and the other may be an N-type doping layer.

[0142] In some embodiments, the solar cell 100 is a main-gridless solar cell. Among several first electrodes 20, the first collecting grid line 21 is disconnected at the first series connection region 11 and continuous at the second series connection region 12, and the first busbar 22 is continuous at the first edge series connection region 111 and disconnected at the remaining first series connection regions 11, and continuous at the second series connection region 12.

[0143] In some embodiments, the first electrode 20 may include a first welding segment 201 corresponding to the second series connection region 12, and the second electrode 30 includes a second welding segment 301 corresponding to the first edge series connection region 111. The first welding segment 201 and the second welding segment 301 are used for welding with the solder tape.

[0144] In some embodiments, the width of the first busbar 22 (i.e., the length in the second direction) may be greater than the width of the portion of the first collecting grid line 21 outside the second series connection region 12 (i.e., the portion of the first collecting grid line 21 other than the first welding segment 201) (i.e., the length in the second direction).

[0145] Thus, since the first busbar 22 needs to undertake the function of current collection and transmission, therefore, setting the width of the first busbar 22 wider can reduce the transmission loss during the current collection process and improve the efficiency.

[0146] In addition, as Figure 1 and Figure 2 shown, in the embodiments of the present application, in the first busbar 22, it is only continuous at the first edge series connection region 111, and is disconnected at the other first series connection regions 11. At the same time, the first busbar 22 is continuous at the second series connection region 12 and has a first welding segment 201 at the second series connection region 12. Only the segment of the first busbar 22 closest to the first edge 101 undertakes the current collection function. Therefore, in some embodiments, in order to save the paste to reduce the cost, only this part of the grid segment can be set wider. In such a case, please refer to Figure 1and Figure 2 A plurality of second connection regions 12 may include a second edge connection region 121 closest to the first edge 101. The first bus bar 22 may include a first bus segment located between the second edge connection region 121 and the first edge 101. In some embodiments, the width of the first bus segment (i.e., the length in the second direction) may be greater than the width of the remaining portion of the first bus bar 22 outside the second connection region 12 (i.e., the portion other than the first bus segment and other than the first welding segment 201).

[0147] In this way, by only setting the width of the first bus segment wider, the use of paste can be reduced while reducing the bus bar transmission loss, thereby reducing costs.

[0148] Please refer to Figure 2 , in some embodiments, the width (the length in the first direction) of the first edge bus line 40 is greater than the width (the length in the second direction) of the portion of the first collecting grid line 21 outside the second connection region 12 (i.e., the portion of the first collecting grid line 21 other than the first welding segment 201).

[0149] In this way, since the first edge bus line 40 needs to undertake the bus bar transmission function, setting the width of the first edge bus line 40 wider can also reduce the transmission loss during the bus bar process and improve efficiency.

[0150] In addition, please continue to refer to Figure 2 , in some embodiments, the width (the length in the first direction) of the first auxiliary connection line 60 is greater than the width (the length in the second direction) of the portion of the first collecting grid line 21 outside the second connection region 12 (i.e., the portion of the first collecting grid line 21 other than the first welding segment 201).

[0151] In this way, since the first auxiliary connection line 60 functions to transmit and collect current when a virtual solder joint occurs, setting the width of the first auxiliary connection line 60 wider can also reduce the transmission loss during the bus bar process and improve efficiency.

[0152] In some embodiments, the width of the first auxiliary connection line 60 may be the same as the width of the first edge bus line 40.

[0153] In addition, as Figure 1 and Figure 2 shown, in some embodiments, in the solar cell 100, a chamfer is formed at the intersection of the first edge 101 and the adjacent edge, and the first electrode 20 is correspondingly provided at the chamfer. Therefore, as Figure 1 and Figure 2As shown, in order to connect the first edge bus bar 40 to the first electrode 20, the first edge bus bar 40 is present in the bent portion at the chamfer. Of course, it can be understood that in some embodiments, if there is no chamfer in the solar cell 100, there is no need to provide a bent portion.

[0154] As Figure 1 and Figure 2 shown, in some embodiments, a plurality of second series connection regions 12 include a second edge series connection region 121 closest to the first edge 101 (i.e., the second series connection region 12 adjacent to the first edge series connection region 111). The first electrode 20 is continuous at the second edge series connection region 121, and the second electrode 30 is discontinuous at the second edge series connection region 121. The solar cell 100 further includes a second auxiliary connection line 70. The second auxiliary connection line 70 is disposed within the second edge series connection region 121. In the second direction, the second auxiliary connection line 70 connects the first bus bar 22 and at least one first collection grid line 21 located on one side of the first bus bar 22.

[0155] In this way, by providing the second auxiliary connection line 70 within the second edge series connection region 121, it is possible to effectively avoid the phenomenon that the solder tape within the second edge series connection region 121 is poorly soldered or has poor contact at the first bus bar 22, resulting in the inability to collect the current transmitted from the first bus bar 22.

[0156] Specifically, as Figure 2 shown, in such an embodiment, the number of the second auxiliary connection lines 70 may be the same as the number of the first bus bars 22, and the two correspond one by one. When the first bus bar 22 is in the middle position (i.e., there are first collection grid lines 21 on both sides of the first bus bar 22), the second auxiliary connection line 70 connects the first bus bar 22 and also connects two first collection grid lines 21 adjacent to the first bus bar 22 (i.e., the first collection grid lines 21 located on both sides of and adjacent to the first bus bar 22).

[0157] In some embodiments, the width of the second auxiliary connection line 70 (the length in the first direction) may be greater than the width of the portion of the first collection grid line 21 outside the second series connection region 12 (i.e., the portion of the first collection grid line 21 other than the first welding segment 201) (the length in the second direction). In this way, since the second auxiliary connection line 70 functions to transmit and converge current when poor soldering occurs at the first bus bar 22, setting the width of the second auxiliary connection line 70 wider can also reduce the transmission loss during the converging process and improve the efficiency.

[0158] As Figure 1 and Figure 3As shown, in some embodiments, a plurality of second connection regions 12 include a third-edge connection region 122 closest to the second edge 102. There is no first connection region 11 between the third-edge connection region 122 and the second edge 102. That is to say, as Figure 1 and Figure 3 shown, among the first connection region 11 and the second connection regions 12, the connection region closest to the second edge 102 is the second connection region 12, and this second connection region 12 is denoted as the third-edge connection region 122. There are no other connection regions between the third-edge connection region 122 and the second edge 102.

[0159] A plurality of second electrodes 30 include a plurality of second collection grid lines 31 and at least one second bus grid line 32. The second collection grid lines 31 are discontinuous at the third-edge connection region 122 and continuous at the first connection region 11. The second bus grid line 32 is continuous at the third-edge connection region 122. The first electrode 20 is continuous at the second-edge connection region 121.

[0160] That is, the second electrode 30 includes at least two types of grid lines. One is the second collection grid line 31, and the other is the second bus grid line 32. The second collection grid lines 31 are discontinuous at the third-edge connection region 122, while the second bus grid line 32 is continuous at the third-edge connection region 122. The first electrode 20 is also continuous at the third-edge connection region 122.

[0161] The solar cell 100 further includes a second-edge bus line 50, a second insulating layer, and a third auxiliary connection line 80. The second-edge bus line 50 is closer to the second edge 102 than the third-edge connection region 122. The second-edge bus line 50 is electrically connected to at least a part of the second collection grid lines 31 and electrically connected to the second bus grid line 32. Specifically, to avoid the battery from having hidden cracks caused by welding at the edge position of the second edge 102, the second-edge bus line 50 is not used for welding. It is used to collect the current of the part of the second collection grid lines 31 between the third-edge connection region 122 and the second edge 102, and then the current is collected through the second bus grid line 32 to the same-polarity solder tape in the first connection region 11 adjacent to the third-edge connection region 122 (i.e., Figure 1 and Figure 3 the rightmost first connection region 11 in), so as to collect the current of the electrodes in the edge region of the second electrode 30 located at the second edge 102, improving the efficiency of the solar cell 100. If the second-edge bus line 50 and the second bus grid line 32 are not provided, it will cause the part of the second electrode 30 between the third-edge connection region 122 and the second edge 102 to form isolated electrodes, resulting in the inability to collect the current of this part.

[0162] The third auxiliary connection line 80 is disposed within the third edge series connection region 122. In the second direction, the third auxiliary connection line 80 is provided on at least one side of the second busbar line 32. The third auxiliary connection line 80 connects at least two first electrodes 20 located on the same side of the second busbar line 32. Among them, in some embodiments, preferably, the at least two first electrodes 20 connected to the third auxiliary connection line 80 include the first electrode 20 adjacent to the second busbar line 32 (i.e., Figure 1 and Figure 3 the first electrode 20 closest to the second busbar line 32 in Figure 1 and Figure 3 ). That is to say, in some embodiments, the third auxiliary connection line 80 preferably connects the first electrode 20 closest to the second busbar line 32, and the third auxiliary connection line 80 also connects at least one of the remaining first electrodes 20 located on the same side as the second electrode 30. That is, the third auxiliary connection line 80 preferably connects at least the first electrode 20 adjacent to the second busbar line 32 and at least one of the remaining first electrodes 20 on the same side.

[0163] Thus, by providing the second edge busbar line 50 and the second busbar line 32, the current collected by the isolated electrodes of at least some of the first electrodes 20 located between the third edge series connection region 122 and the second edge 102 can be collected to the same-polarity solder tape within the first series connection region 11 adjacent to the third edge series connection region 122, effectively avoiding the occurrence of hidden cracks caused by welding at the second edge 102 of the solar cell 100 while ensuring the efficiency of the solar cell 100. At the same time, by providing the third auxiliary connection line 80, even if there is a virtual solder between the first electrode 20 near the second insulating layer and the solder tape due to the setting of the second insulating layer, due to the existence of the third auxiliary connection line 80, the first electrode 20 with virtual solder can also achieve current collection and output through the third auxiliary connection line 80, reducing the impact caused by virtual solder, thereby ensuring the efficiency of the solar cell 100.

[0164] As Figure 1 and Figure 3 shown, in some embodiments, the solar cell 100 is a main-gridless solar cell. Among several second electrodes 30, the second collecting grid line 31 is disconnected at the second series connection region 12 and continuous at the first series connection region 11. The second busbar line 32 is continuous at the third edge series connection region 122 and disconnected at the remaining second series connection regions 12, and continuous at the first series connection region 11.

[0165] As Figure 1 and Figure 3 shown, in the embodiments of the present application, in order to minimize the impact of virtual soldering as much as possible, when there are first electrodes 20 on both sides of the second busbar line 32, it is preferred that third auxiliary connection lines 80 are provided on both sides of the second busbar line 32 simultaneously.

[0166] In some embodiments, the width of the second bus bar 32 (i.e., the length in the second direction) may be greater than the width of the portion of the second collecting grid line 31 that is outside the first series connection region 11 (i.e., the portion of the second collecting grid line 31 other than the second welding segment 301) (i.e., the length in the second direction).

[0167] Thus, since the second bus bar 32 needs to undertake the function of bus bar transmission, setting the width of the second bus bar 32 wider can reduce the transmission loss during the bus bar process and improve the efficiency.

[0168] As Figure 3 shown, in some embodiments, the width of the second edge bus line 50 (the length in the first direction) is greater than the width of the portion of the second collecting grid line 31 that is outside the first series connection region 11 (i.e., the portion of the second collecting grid line 31 other than the second welding segment 301) (the length in the second direction).

[0169] Thus, since the second edge bus line 50 needs to undertake the function of bus bar transmission, setting the width of the second edge bus line 50 wider can also reduce the transmission loss during the bus bar process and improve the efficiency.

[0170] Specifically, in such an embodiment, the width of the second edge bus line 50 may be the same as the width of the second welding segment 301. In this way, it can be ensured that no large bus bar loss will be caused during the bus bar process. At the same time, during printing, only a screen slot of the same size needs to be opened on the screen to print the three simultaneously, which can effectively save the manufacturing process and reduce the manufacturing difficulty.

[0171] In addition, as Figure 3 shown, in some embodiments, the width of the third auxiliary connection line 80 (the length in the first direction) is greater than the width of the portion of the second collecting grid line 31 that is outside the first series connection region 11 (i.e., the portion of the second collecting grid line 31 other than the second welding segment 301) (the length in the second direction).

[0172] Thus, since the third auxiliary connection line 80 functions to transmit and collect current when a virtual soldering occurs, setting the width of the third auxiliary connection line 80 wider can also reduce the transmission loss during the bus bar process and improve the efficiency.

[0173] In some embodiments, the width of the third auxiliary connection line 80 may be the same as the width of the second edge bus line 50.

[0174] As Figure 1 and Figure 3As shown, in some embodiments, the second edge bus bar 50 is electrically connected to all the second collecting grid lines 31. In this way, the current collected by the isolated grid line segments of all the second collecting grid lines 31 between the third edge series connection region 122 and the second edge 102 can be collected, maximizing the efficiency of the solar cell 100.

[0175] Of course, in some embodiments, the second edge bus bar 50 may also be electrically connected to some of the second collecting grid lines 31. In such a case, the number of the second collecting grid lines 31 not electrically connected to the second edge bus bar 50 is less than or equal to 4. In this way, even if some of the second collecting grid lines 31 are not connected to the second edge bus bar 50, the number is small and it will not cause excessive efficiency loss and lead to defective products.

[0176] In some embodiments, the third auxiliary connection line 80 is connected to 2 - 20 first electrodes 20. By setting the number of the first electrodes 20 connected to the third auxiliary connection line 80 within this reasonable range, the influence brought by false soldering can be reduced or even eliminated as much as possible.

[0177] In the embodiments of the present application, the number of the second bus bars 32 may be single. In such a case, the third auxiliary connection line 80 may be provided only on one side of the second bus bar 32, or may be provided on both sides of the second bus bar 32, and specific limitations are not made here. When there are first electrodes 20 on both sides of the second bus bar 32, it is preferred to provide the third auxiliary connection line 80 on both sides.

[0178] In addition, it should be noted that in the present application, when the number of the second bus bars 32 is multiple, the third auxiliary connection line 80 may also be provided only on one side or both sides of some of the second bus bars 32, while the third auxiliary connection line 80 may not be provided on both sides of the remaining second bus bars 32. In such a case, it can also solve the problem of false soldering at some positions. In the present application, it is preferred that the third auxiliary connection line 80 is provided on both sides of each second bus bar 32.

[0179] Of course, as Figure 1 and Figure 3 shown, in some embodiments, the number of the second bus bars 32 may also be multiple. Setting multiple second bus bars 32 can shorten the current collection path, effectively reduce the collection and transmission loss, and improve the efficiency.

[0180] In such a case, the third auxiliary connection line 80 is provided between adjacent two second bus bars 32, and the third auxiliary connection line 80 between adjacent two second bus bars 32 is connected to all the first electrodes 20 between adjacent two second bus bars 32.

[0181] In this way, by connecting the third auxiliary connection line 80 to all the first electrodes 20 between two adjacent second bus bars 32, the influence caused by poor soldering can be basically and completely eliminated, and the efficiency of the solar cell 100 can be improved as much as possible.

[0182] Of course, in some alternative embodiments, the third auxiliary connection line 80 may also be provided only on one side of the second bus bar 32, and specific details are not limited herein.

[0183] Specifically, in such an embodiment, the number of the second bus bars 32 in the solar cell 100 can be selected according to the actual conditions such as the size of the cell and the loss during transmission, and specific details are not limited herein.

[0184] As Figure 1 and Figure 3 shown, in some embodiments, several first series connection regions 11 may further include a fourth edge series connection region 112 closest to the second edge 102 (i.e., the first series connection region 11 adjacent to the third edge series connection region 122). The second electrode 30 is continuous at the fourth edge series connection region 112, the first electrode 20 is discontinuous at the fourth edge series connection region 112, and the solar cell 100 may further include a fourth auxiliary connection line 90. The fourth auxiliary connection line 90 is disposed in the fourth edge series connection region 112. In the second direction, the fourth auxiliary connection line 90 connects the second bus bar 32 and at least one second collecting grid line 31 located on one side of the second bus bar 32.

[0185] In this way, by disposing the fourth auxiliary connection line 90 in the fourth edge series connection region 112, the phenomenon that the current transmitted from the second bus bar 32 cannot be collected due to poor soldering or poor contact of the solder tape in the fourth edge series connection region 112 at the second bus bar 32 can be effectively avoided.

[0186] Specifically, as Figure 3 shown, in such an embodiment, the number of the fourth auxiliary connection lines 90 may be the same as the number of the second bus bars 32, and the two are in one-to-one correspondence. When the second bus bar 32 is in the middle position (i.e., there are second collecting grid lines 31 on both sides of the second bus bar 32), the fourth auxiliary connection line 90 connects the second bus bar 32 and two second collecting grid lines 31 adjacent to the second bus bar 32 (i.e., the second collecting grid lines 31 located on both sides of and adjacent to the second bus bar 32).

[0187] In some embodiments, the width of the fourth auxiliary connection line 90 (the length in the first direction) is greater than the width of the portion of the second collection grid line 31 outside the first series connection region 11 (i.e., the portion of the second collection grid line 31 other than the second welding segment 301) (the length in the second direction). Thus, since the fourth auxiliary connection line 90 functions to transmit and collect current when a virtual soldering occurs at the second bus bar 32, setting the width of the fourth auxiliary connection line 90 to be wider can also reduce the transmission loss during the current collection process and improve the efficiency.

[0188] Embodiment VIII

[0189] This embodiment provides a battery module, including the solar cell 100 in the above embodiment.

[0190] The battery module may include a plurality of solar cells 100. The plurality of solar cells 100 in the battery module may be connected in series in sequence to form a battery string. Each battery string may be connected in series, in parallel, or in a series-parallel combination to achieve the current collection and output. For example, the connection between each solar cell may be realized by welding a solder tape, and the connection between each battery string may be realized by a bus bar.

[0191] The battery module may further include a metal frame, a backsheet, a photovoltaic glass, and a glue film (not shown in the figures). The glue film may be filled between the light-facing surface of the solar cell 100 and the photovoltaic glass, the backlight surface and the backsheet, and adjacent solar cells, etc. As a filler, it may be a transparent colloid with good light transmittance and anti-aging performance. For example, the glue film may adopt an EVA glue film or a POE glue film, which can be specifically selected according to the actual situation and is not limited herein.

[0192] The photovoltaic glass may cover the glue film on the light-facing surface of the solar cell 100. The photovoltaic glass may be ultra-white glass, which has a high light transmittance, high transparency, and excellent physical, mechanical, and optical properties. For example, the light transmittance of the ultra-white glass can reach more than 92%, which can protect the solar cell 100 as much as possible without affecting the efficiency of the solar cell 100. At the same time, the glue film can bond the photovoltaic glass and the solar cell 100 together, and the presence of the glue film can seal and insulate the solar cell 100 and prevent water and moisture.

[0193] The backsheet can be attached to the adhesive film on the backlight side of the solar cell 100. The backsheet can protect and support the solar cell 100, and has reliable insulation, water resistance and aging resistance. There can be multiple choices for the backsheet, usually tempered glass, plexiglass, aluminum alloy TPT composite adhesive film, etc., and its specific settings can be determined according to specific circumstances and are not limited here. The whole composed of the backsheet, the solar cell 100, the adhesive film and the photovoltaic glass can be arranged on the metal frame. The metal frame serves as the main external support structure of the entire battery module and can stably support and install the battery module. For example, the battery module can be installed at the required installation position through the metal frame.

[0194] The beneficial effects of the battery module in this embodiment are equivalent to those of the above-mentioned solar cell 100 and will not be elaborated here.

[0195] Embodiment Nine

[0196] The embodiment provides a photovoltaic module, including the battery module in the above embodiment.

[0197] The photovoltaic system can be applied in photovoltaic power stations, such as ground power stations, rooftop power stations, water surface power stations, etc., and can also be applied to devices or apparatuses that use solar energy for power generation, such as user solar power supplies, solar street lamps, solar cars, solar buildings, etc. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is to say, the photovoltaic system can be applied in all fields that require solar power generation. Taking the photovoltaic power generation system network as an example, the photovoltaic system can include a photovoltaic array, a busbar box and an inverter. The photovoltaic array can be an array combination of multiple battery modules. For example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the busbar box, and the busbar box can collect the current generated by the photovoltaic array. After the collected current flows through the inverter and is converted into alternating current required by the commercial power grid, it is connected to the commercial power grid to achieve solar power supply.

[0198] The beneficial effects of the photovoltaic system in this embodiment are equivalent to those of the above-mentioned battery module and will not be elaborated here.

[0199] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A solar cell, characterized in that: It includes a silicon substrate and electrodes arranged on the silicon substrate, wherein the electrodes include a first electrode and a second electrode; The first electrode comprises: a plurality of first collecting grid lines and at least one first bus grid line; The second electrode comprises: a plurality of second collecting grid lines and at least one second bus grid line; The silicon substrate has a light-facing surface and a backlight surface that are arranged opposite to each other, and a first region and a second region are alternately arranged on the backlight surface along a second direction, the silicon substrate comprises a doping layer, the doping layer comprises a first doping layer and a second doping layer, the first doping layer and the second doping layer have different polarities, the first doping layer is arranged in the first region, and the second doping layer is arranged in the second region; The first electrode is arranged in the first region, and the second electrode is arranged in the second region; The first busbar line and the second busbar line include: a connecting conductor and a thin grid line; The connecting conductor extends along a first direction, and the fine gate line is arranged on a surface of the connecting conductor facing the silicon substrate; The connecting conductor is not in physical contact with the doped layer, and the fine gate line is in physical contact with the doped layer; It also includes a collector wire, which is arranged on the silicon substrate and extends along a second direction, and the second direction intersects the first direction; at least one end of the connecting conductor is connected to the collector wire, and the collector wire is not in physical contact with the doping layer.

2. The solar cell according to claim 1, characterized in that The fine gate lines extend along the first direction.

3. The solar cell according to claim 1, characterized in that A plurality of fine gate lines are provided and spaced apart along the first direction.

4. The solar cell according to claim 3, characterized in that Along the first direction, the fine grid lines are collinear.

5. The solar cell according to claim 3, characterized in that: Along the first direction, at least some of the fine grid lines are staggered.

6. The solar cell according to claim 2, characterized in that: Along the first direction, at least one of the thin gate lines is equidistant from edges of the connecting conductors on both sides.

7. The solar cell according to claim 2, characterized in that: Along the first direction, at least one of the thin gate lines is at different distances from edges of the connecting conductors on both sides.

8. The solar cell according to claim 3, characterized in that: Along the first direction, distances between adjacent fine grid lines are equal.

9. The solar cell according to claim 3, characterized in that: Along the first direction, distances between at least some adjacent fine grid lines are unequal.

10. The solar cell according to claim 1, characterized in that Along the first direction, the total length of the thin gate lines is 10% to 90% of the total length of the connecting conductor.

11. The solar cell according to claim 10, characterized in that Along the first direction, the total length of the thin gate lines is 50% to 90% of the total length of the connecting conductor.

12. The solar cell according to claim 1, characterized in that: The current collecting wire comprises an edge bus line, and the edge bus line is arranged at an edge position of the silicon substrate.

13. The solar cell according to claim 1, characterized in that: The doping layer comprises a first doping layer and a second doping layer, the first doping layer is arranged in the first region, and the second doping layer is arranged in the second region; The thin gate line of the first bus gate line is in physical contact with the first doping layer; The thin gate line of the second bus gate line is in physical contact with the second doping layer.

14. The solar cell according to claim 12, characterized in that: The backlight surface has a first edge and a second edge opposite to each other in a first direction, the backlight surface has a plurality of first series connection areas and a plurality of second series connection areas, the first series connection areas include a first edge series connection area closest to the first edge, and there is no second series connection area between the first edge series connection area and the first edge; All the first electrodes and all the second electrodes are arranged to cross the first series connection area and the second series connection area, the first collector gate line is discontinuous at the first edge series connection area and continuous at the second series connection area, the first bus gate line is continuous at the first edge series connection area and the second series connection area, and the second electrode is continuous at the first edge series connection area; The edge bus line includes a first edge bus line, the first edge bus line is closer to the first edge than the first edge series connection area, the first edge bus line is electrically connected to at least part of the first collecting grid line and is electrically connected to the first bus grid line; The solar cell also includes: a first auxiliary connecting line arranged in the first edge series area, in the second direction, the first auxiliary connecting line is provided on at least one side of the first bus bar line, the first auxiliary connecting line connects at least two of the second electrodes located on the same side of the first bus bar line, wherein the at least two second electrodes connected to the first auxiliary connecting line include the second electrode adjacent to the first bus bar line.

15. The solar cell according to claim 14, characterized in that The first edge bus line is electrically connected to all the first collecting gate lines; or The first edge bus line is electrically connected to a portion of the first collecting gate lines, and the number of the first collecting gate lines that are not electrically connected to the first edge bus line is less than or equal to four.

16. The solar cell according to claim 14, characterized in that The width of the first bus gate line is greater than the width of a portion of the first collecting gate line located outside the second series connection region.

17. The solar cell according to claim 14, characterized in that: The width of the first edge bus line is greater than the width of a portion of the first collecting gate line located outside the second series connection region.

18. The solar cell according to claim 14, characterized in that The width of the first auxiliary connection line is greater than the width of a portion of the first collecting gate line located outside the second series connection area.

19. The solar cell according to claim 14, characterized in that: The plurality of second series connection areas include a second edge series connection area closest to the first edge, the first electrode is continuous at the second edge series connection area, and the second electrode is discontinuous at the second edge series connection area. The solar cell also includes a second auxiliary connection line, and the second auxiliary connection line is arranged in the second edge series connection area. In the second direction, the second auxiliary connection line connects the first bus grid line and at least one first collection grid line located on one side of the first bus grid line.

20. The solar cell according to claim 19, characterized in that: The width of the second auxiliary connection line is greater than the width of a portion of the first collecting gate line located outside the second series connection area.

21. The solar cell according to claim 14, characterized in that: The plurality of second serial connection areas include a third edge serial connection area closest to the second edge, and no first serial connection area is provided between the third edge serial connection area and the second edge; The second collector gate line is discontinuous at the third edge series connection area and continuous at the first series connection area, the second collector gate line is continuous at the third edge series connection area and the first series connection area, and the first electrode is continuous at the third edge series connection area; The edge bus line further includes a second edge bus line, the second edge bus line is closer to the second edge than the third edge series connection area, the second edge bus line is electrically connected to at least a portion of the second collecting grid line and is electrically connected to the second bus grid line; The solar cell also includes: a third auxiliary connecting line arranged in the third edge series area, and in the second direction, the third auxiliary connecting line is provided on at least one side of the second bus bar line, and the third auxiliary connecting line connects at least two of the first electrodes located on the same side of the second bus bar line, wherein the at least two first electrodes connected to the third auxiliary connecting line include the first electrode adjacent to the second bus bar line.

22. The solar cell according to claim 21, characterized in that: The second edge bus line is electrically connected to all the second collecting gate lines; or The second edge bus line is electrically connected to a portion of the second collecting gate lines, and the number of the second collecting gate lines that are not electrically connected to the second edge bus line is less than or equal to four.

23. The solar cell according to claim 21, characterized in that The width of the second bus gate line is greater than the width of a portion of the second collecting gate line located outside the first series connection region.

24. The solar cell according to claim 21, characterized in that The width of the second edge bus line is greater than the width of a portion of the second collecting gate line located outside the first series connection region.

25. The solar cell according to claim 21, characterized in that The width of the third auxiliary connection line is greater than the width of a portion of the second collecting gate line located outside the first series connection area.

26. The solar cell according to claim 21, characterized in that Several of the first series connection areas include a fourth edge series connection area closest to the second edge, the second electrode is continuous at the fourth edge series connection area, and the first electrode is discontinuous at the fourth edge series connection area. The solar cell also includes a fourth auxiliary connection line, and the fourth auxiliary connection line is arranged in the fourth edge series connection area. In the second direction, the fourth auxiliary connection line connects at least one of the second bus grid lines and at least one of the second collection grid lines located on one side of the second bus grid line.

27. The solar cell according to claim 26, characterized in that: The width of the fourth auxiliary connection line is greater than the width of a portion of the second collecting gate line located outside the first series connection area.

28. A battery assembly, characterized in that: A solar cell comprising any one of claims 1 to 27.

29. A photovoltaic system, characterized in that: A battery assembly comprising the battery assembly of claim 28.

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