No main grid electrode structure, interdigitated back contact battery cells and battery modules

Abstract

The present invention provides a main-grid-free electrode structure, a forked back-contact battery cell, and a battery assembly. The battery assembly includes upper glass, glass fiber, upper POE film or EVA film, battery string, lower POE film or EVA film, and lower glass, which are sequentially laid from top to bottom. The electrode structure adopts a main-grid-free design, including multiple p+ sub-grids and multiple n+ sub-grids, the p+ sub-grid is arranged on the p+ region passivation film, the n+ sub-grid is arranged on the n+ region passivation layer, and the p+ sub-grid and the n+ sub-grid are arranged alternately. According to different crystalline silicon, the present invention designs different numbers of sub-grid electrodes on the emitter region / base region, which can improve the collection of minority carriers by the electrode, and can perfectly distinguish whether the electrode is a positive electrode or a negative electrode, so as to facilitate the distinction during assembly welding and reduce the probability of errors in assembly welding. The present invention uses conductive glue + conductive wire to connect the grid line electrode to collect current, which can reduce the silver consumption, thereby greatly reducing the production cost.

Description

Technical Field

[0001] The present invention relates to the field of solar cell and battery assembly manufacturing, and in particular to a main grid electrode structure without a main grid electrode, an interdigitated back contact battery sheet, and a battery assembly. Background Art

[0002] The industrialized production of modern solar cells is developing towards high efficiency and low cost. For back-contact solar cells, the characteristics are that there is no electrode on the front of the battery, and the positive and negative electrode metal grid lines are arranged in a finger-like cross-arrangement on the back of the battery. It has a higher short-circuit current and can effectively reduce the temperature coefficient of the battery, and has great development potential.

[0003] However, the existing back-contact cells and battery modules made of series-connected cells have complicated technical processes. The number of sub-grid electrodes in the emitter and base regions in the electrode pattern is not matched and is unreasonable, resulting in losses in the collection of minority carriers in the electrode, affecting the conversion efficiency. The main grid design is used in the electrode pattern, and the positive main grid is the same as the negative main grid, and the number of main grids is large and the width is large, which makes it difficult to distinguish the battery when the component is welded, resulting in welding errors. Secondly, the silver consumption is high, resulting in high manufacturing costs. When a main grid-free structure is used in the electrode pattern, although the manufacturing cost of the battery cell can be reduced, it is necessary to add insulating glue and conductive glue when welding at the component end, or directly use a conductive backplane, but the current technology is still immature. Summary of the invention

[0004] Purpose of the invention: To propose a main grid-free electrode structure, further propose an interdigitated back-contact cell sheet comprising the above electrode structure, and further propose a cell assembly comprising the interdigitated back-contact cell sheet, so as to solve the above problems existing in the prior art.

[0005] In the first aspect, a main-gate-free electrode structure is proposed, which includes at least one p+ segment and at least one n+ segment. The electrode structure adopts a main-gate-free design, with only a sub-gate, which includes multiple p+ sub-gates and multiple n+ sub-gates. The p+ sub-gate is arranged on the p+ region passivation film, and the n+ sub-gate is arranged on the n+ region passivation layer. The p+ sub-gate and the n+ sub-gate are arranged alternately. According to the design requirements of different numbers of p+ sub-gates and n+ sub-gates, a corresponding number of p+ sub-gates are arranged on a single p+ segment, and a corresponding number of n+ sub-gates are arranged on a single n+ segment. The number of sub-gates is 60 to 300.

[0006] In a second aspect, an interdigitated back contact cell is provided, the cell comprising a crystalline silicon substrate, the back surface of the crystalline silicon substrate forming an alternating arrangement of p+ regions and n+ regions. The p+ region is composed of a plurality of p+ segments as described in the first aspect. The n+ region is composed of a plurality of n+ segments as described in the first aspect.

[0007] On the third aspect, a battery assembly is proposed, in which upper glass, glass fiber, upper POE film or EVA film, battery string, lower POE film or EVA film, and lower glass are laid in sequence from top to bottom, and prepared through processes such as lamination, trimming, framing and wiring to obtain a battery assembly.

[0008] In a further embodiment of the third aspect, the battery string includes a plurality of interdigitated back-contact battery cells, a plurality of conductive wires, a plurality of conductive adhesives and a plurality of bus bars. The plurality of interdigitated back-contact battery cells include a first battery cell, a second battery cell ... a Cth battery cell.

[0009] The conductive wires include p+ conductive wires and n+ conductive wires. The p+ conductive wires are vertically connected to the p+ auxiliary grid through conductive glue and are discontinuously not connected to the n+ auxiliary grid. The n+ conductive wires are vertically connected to the n+ auxiliary grid through conductive glue and are discontinuously not connected to the p+ auxiliary grid. The p+ conductive wires and the n+ conductive wires are alternately arranged, and the number of the conductive wires is 4 to 50.

[0010] The bus is arranged on the upper and lower (or left and right) sides of the module, including the first bus, the second bus and the third bus. The first bus and the second bus are used to collect current and export it to the external circuit, and the third bus is used to transfer current between adjacent battery strings in the middle horizontal (or vertical) direction. The first bus is connected to the p+ conductive wire, the second bus is connected to the n+ conductive wire, and the third bus is connected to the n+ conductive wire and the p+ conductive wire of two adjacent battery cells.

[0011] In a further embodiment of the third aspect, the interdigitated back contact cell is any one of a P-type crystalline silicon cell and an N-type crystalline silicon cell, and the relationship between the p+ sub-gate and the n+ sub-gate satisfies the following formula: when the interdigitated back contact cell is of P type, the number of n+ sub-gates ≥ 1.3 times the number of p+ sub-gates, and the number of n+ sub-gates set on a single n+ segment is: 5>n+ number of sub-gates ≥ 2; when the interdigitated back contact cell is of N type, the number of p+ sub-gates ≥ 1.3 times the number of n+ sub-gates, and the number of p+ sub-gates set on a single p+ segment is: 5>p+ number of sub-gates ≥ 2.

[0012] In a further embodiment of the third aspect, the p+ sub-gate is formed by a plurality of p+ sub-gates arranged at intervals, and a p+ sub-gate isolation region is set between two adjacent p+ sub-gates; the n+ sub-gate is formed by a plurality of n+ sub-gates arranged at intervals, and an n+ sub-gate isolation region is set between two adjacent n+ sub-gates; the p+ sub-gate isolation regions of adjacent p+ sub-gates and the n+ sub-gate isolation regions of adjacent n+ sub-gates are staggered.

[0013] In a further embodiment of the third aspect, the p+ conductive wire and the conductive glue pass through the center of the n+ auxiliary gate isolation region, and the n+ conductive wire and the conductive glue pass through the center of the p+ auxiliary gate isolation region.

[0014] In a further embodiment of the third aspect, when the number of p+ sub-gates arranged on the single p+ segment is greater than or equal to 2, the two ends of the multiple p+ sub-gates parallel to the upper and lower sections of the single p+ segment are connected by an anti-breaking gate, and when the number of n+ sub-gates arranged on the single n+ segment is greater than or equal to 2, the two ends of the multiple n+ sub-gates parallel to the upper and lower sections of the single p+ segment are connected by an anti-breaking gate.

[0015] In a further embodiment of the third aspect, the conductive wire is made of a copper welding strip or an aluminum welding strip, the conductive adhesive is selected from a low resistivity thermosetting material, mainly including a polymer matrix, a conductive filler, a curing agent / initiator / catalyst and an additive, wherein the polymer matrix includes an acrylic system, an epoxy system, a silicone system, etc., the conductive filler includes silver, silver-coated copper, gold and nickel, etc., and the resistivity of the conductive adhesive is required to be less than 0.00001Ω.cm; the width of the conductive adhesive is 100~800μm, and the conductive The width of the wire is 50μm smaller than the width of the conductive glue, the width of the p+ sub-gate isolation region and the n+ sub-gate isolation region are both 500~1500μm, the width of the conductive wire and the conductive glue are smaller than the width of the p+ sub-gate isolation region and the n+ sub-gate isolation region, and meet the following conditions: p+ sub-gate isolation region = n+ sub-gate isolation region ≥ conductive glue width + 400μm. Under the existing alignment accuracy, the conductive glue can be completely in the p+ sub-gate isolation region or the n+ sub-gate isolation region, thereby achieving perfect connection between the conductive wire and the conductive glue.

[0016] Fourthly, a method for assembling a battery module is proposed, wherein the arrangement of the battery layers of the battery module is arranged according to the formula C=A×B, A represents the number of battery strings, B represents the number of battery cells in a single battery string, and C represents the number of all battery cells in the module, (considering that the electrodes of the interdigitated back contact batteries appear in pairs from left to right in the order of p+ / n+ / p+ / n+…, and the battery strings are connected in such a way that the p+ of the first battery cell is connected to the n+ of the second battery cell, the p+ of the second battery cell is connected to the n+ of the third battery cell, and so on, the second battery cell is connected to the n+ of the third battery cell, and so on, and ... When the horizontal plane of the cell is rotated 180°, the electrodes of the second cell can be arranged from left to right in the order of n+ / p+ / n+ / p+…. When the edges of the front and rear cell sheets are aligned, it can be ensured that the electrodes of the first cell p+ / n+ / p+ / n+… and the electrodes of the second cell n+ / p+ / n+ / p+… can be aligned one by one; therefore, in this scheme, the horizontal plane of the even-numbered cells is rotated 180°, and the electrodes of the base-numbered cells p+ / n+ / p+ / n+… and the electrodes of the even-numbered cells n+ / p+ / n+ / p+… can be aligned one by one, which can be achieved in the existing Perc The battery assembly is perfectly compatible with the back contact battery assembly on the basis of serial welding. ) When B=1, C=B=A=1, when B>1, and 216≥C≥B≥A≥1; the way to assemble the battery string is that when B>1, after connecting the p+ conductive wire of the first battery cell to the first bus bar, the second battery cell is rotated 180° in the horizontal plane, and the edges of the two batteries are aligned, so that the p+ conductive wire on the second battery cell is in a straight line with the n+ conductive wire on the first battery cell, and the p+ conductive wire of the second battery cell is aligned with the n+ conductive wire on the first battery cell. The n+ conductive lines of the cell sheets are connected to each other, and then the third cell is placed normally, so that the p+ conductive line on the third cell is in a straight line with the n+ conductive line of the second cell, and the p+ conductive line of the third cell is connected to the n+ conductive line of the second cell, and the above operation is repeated until the Bth cell is placed, so that the p+ conductive line of the Bth cell is connected to the n+ conductive line of the B-1th cell, and the n+ conductive line of the Bth cell is connected to the second bus (or the third bus), forming a battery string structure to form a solar cell group.

[0017] The present invention has the following beneficial effects:

[0018] 1. According to different crystalline silicon, design the number of sub-gate electrodes in the emitter region / base region to improve the collection of minority carriers by the electrodes.

[0019] 2. The different number of sub-grids in the emitter region / base region can perfectly distinguish whether the electrode is a positive electrode or a negative electrode, making it easier to distinguish during component welding and reducing the probability of errors in component welding.

[0020] 3. The main grid-free design uses conductive glue + conductive wire to connect the grid electrode to collect current, which can reduce silver consumption and thus greatly reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the interdigital back contact battery electrode structure provided by the present invention.

[0022] Figure 2 It is a schematic structural diagram of the interdigital back contact battery conductive line connection provided by the present invention.

[0023] Figure 3 yes Figure 2 Enlarged view of area a.

[0024] Figure 4 It is a structural schematic diagram of a main-grid-free battery string connected by conductive wires provided by the present invention.

[0025] Figure 5 It is a partial diagram of a solar cell string of a main-grid-free battery assembly provided by the present invention.

[0026] Figure 6 It is a partial cross-sectional view of a main-grid-free battery assembly provided by the present invention.

[0027] In the figure: 1, upper glass; 2, glass fiber; 3, upper POE film / EVA film; 4, N-type interdigital back contact battery cell; 41, p+ auxiliary grid; 411, p+ sub-auxiliary grid; 412, anti-break grid; 4110, p+ auxiliary grid partition area; 42, n+ auxiliary grid; 421, n+ sub-auxiliary grid; 4200, n+ auxiliary grid partition area; 43, conductive wire; 431, p+ conductive wire; 432, n+ conductive wire; 441, p+ conductive glue; 442, n+ conductive glue; 451, first bus; 452, second bus; 453, third bus; 5, lower POE film / EVA film; 6, lower glass;

[0028] C. Battery string;

[0029] B. Number of batteries in a single string;

[0030] A. Number of battery strings;

[0031] L1, width of p+ auxiliary gate isolation region;

[0032] L2, width of p+ sub-gate partition region;

[0033] W1, width of p+ conductive glue;

[0034] W2, n+ conductive glue width. DETAILED DESCRIPTION

[0035] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features known in the art are not described. Example

[0036] This embodiment proposes an electrode structure and a battery assembly of an interdigitated back-contact battery, wherein the interdigitated back-contact battery 4 includes a crystalline silicon substrate, a front passivation layer and a front anti-reflection layer, p+ regions and n+ regions alternately arranged on the back surface of the crystalline silicon substrate, a back insulating passivation layer, and an electrode structure.

[0037] The p+ region is composed of a plurality of p+ segments, and the n+ region is composed of a plurality of n+ segments.

[0038] The electrode structure adopts a main grid-free design, such as Figure 1 As shown, there is only a sub-gate, which includes multiple p+ sub-gates 41 and multiple n+ sub-gates 42. The p+ sub-gate 41 is set on the p+ region passivation film, and the n+ sub-gate 42 is set on the n+ region passivation layer. The p+ sub-gate 41 and the n+ sub-gate 42 are arranged alternately. According to the design requirements of different numbers of p+ sub-gates 41 and n+ sub-gates 42, a corresponding number of p+ sub-gates 41 are set on a single p+ segment, and a corresponding number of n+ sub-gates 42 are set on a single n+ segment. The number of sub-gates is 144.

[0039] The battery assembly, such as Figure 6 As shown, glass 1, glass fiber 2, POE film / EVA film 3, battery string C (multiple interdigitated back-contact battery cells 4), POE film / EVA film 5, and glass / back plate 6 are sequentially laid from top to bottom, and prepared through processes such as lamination, trimming, framing, and wiring to obtain a battery assembly.

[0040] The battery string C, such as Figure 4 , 5 As shown, it includes a plurality of interdigitated back contact battery sheets 4, a plurality of conductive wires 43, a plurality of conductive glues and a plurality of bus bars.

[0041] The plurality of interdigitated back-contact batteries 4 include a first battery cell, a second battery cell, ... a Cth battery cell.

[0042] The conductive wire 43 is as follows Figure 1 , 2As shown, it includes a p+ conductive wire 431 and an n+ conductive wire 432. The p+ conductive wire 431 is vertically connected to the p+ sub-gate 41 through a p+ conductive glue 441, and is discontinuously not connected to the n+ sub-gate 42. The n+ conductive wire 432 is vertically connected to the n+ sub-gate 42 through an n+ conductive glue 442, and is discontinuously not connected to the p+ sub-gate 41. The p+ conductive wire 431 and the n+ conductive wire 432 are arranged alternately, and the number of conductive wires is 22.

[0043] The busbar, such as Figure 5 As shown, it is arranged on the upper and lower sides of the module, including a first bus 451, a second bus 452 and a third bus 453. The first bus 451 and the second bus 452 are used to collect current and export it to the external circuit, and the third bus 453 is used for current transmission between adjacent battery strings in the middle. The first bus 451 is connected to the p+ conductive line 431, the second bus 452 is connected to the n+ conductive line 432, and the third bus 453 is connected to the n+ conductive line 432 and the p+ conductive line 431 of two adjacent battery cells.

[0044] The battery layer of the battery module is arranged according to the formula C=A×B, where A represents the number of battery strings, B represents the number of battery cells in a single battery string, and C represents the number of all battery cells in the module. Figure 5As shown, in this embodiment, the battery string C is 24 pieces, the number of battery groups A is 4 groups, and the number of single-string batteries B is 6 pieces; the battery string is assembled in a manner that after the p+ conductive wire 431 of the first battery piece is connected to the first bus 451, the second battery piece is rotated 180° in the horizontal plane, and the left and right edges of the two batteries are aligned, so that the p+ conductive wire 431 on the second battery piece and the n+ conductive wire 432 on the first battery piece are in a straight line, and the p+ conductive wire 431 of the second battery piece and the n+ conductive wire 432 of the first battery piece are connected to each other Then place the third cell normally, so that the p+ conductive line 431 on the third cell is in a straight line with the n+ conductive line 432 of the second cell, and the p+ conductive line 431 of the third cell is connected to the n+ conductive line 432 of the second cell, and repeat the above operation until the sixth cell is placed, so that the p+ conductive line 431 of the sixth cell is connected to the n+ conductive line 432 of the fifth cell, and the n+ conductive line 432 of the sixth cell is connected to the third bus 453, and the single battery string B is completed. Continue to connect the second battery string in series, place the seventh battery cell normally, align it with the upper and lower edges of the sixth battery cell, connect the p+ conductive wire 431 of the seventh battery cell to the third bus 453, rotate the eighth battery cell 180° on the horizontal plane, make the p+ conductive wire 431 on the eighth battery cell and the n+ conductive wire 432 of the seventh battery cell in a straight line, and make the p+ conductive wire 431 of the eighth battery cell and the n+ conductive wire 432 of the seventh battery cell connected to each other, then place the ninth battery cell normally, so that the p+ conductive wire 431 on the ninth battery cell is aligned with the n+ conductive wire 432 on the seventh battery cell. The p+ conductive wire 431 of the eighth cell is in a straight line with the n+ conductive wire 432 of the eighth cell, and the p+ conductive wire 431 of the ninth cell is connected to the n+ conductive wire 432 of the eighth cell, and the above operation is repeated until the twenty-fourth cell is placed, so that the p+ conductive wire 431 of the twenty-fourth cell is connected to the n+ conductive wire 432 of the twenty-third cell, and the n+ conductive wire 432 of the twenty-fourth cell is connected to the second bus 452, completing the 4×6 arrangement of the battery string structure to form a 24-cell solar cell group.

[0045] The interdigitated back contact cell 4 is an N-type crystalline silicon cell. The number of p+ auxiliary gates 41 and the number of n+ auxiliary gates 42 are set, and the relationship between the two satisfies the following formula: the number of p+ auxiliary gates 41: the number of n+ auxiliary gates 42 = 1.33, 1.5, 2. In this embodiment, the number of p+ auxiliary gates 41 is 96, and the number of n+ auxiliary gates 42 is 48.

[0046] The p+ sub-gate 41 is composed of a plurality of p+ sub-gates 411 arranged at intervals, and a p+ sub-gate isolation region 4100 is set between two adjacent p+ sub-gates 411; the n+ sub-gate 42 is composed of a plurality of n+ sub-gates 421 arranged at intervals, and an n+ sub-gate isolation region 4200 is set between two adjacent n+ sub-gates 421; the p+ sub-gate isolation regions 4100 of adjacent p+ sub-gates 41 and the n+ sub-gate isolation regions 4200 of adjacent n+ sub-gates 42 are staggered.

[0047] The p+ conductive wire 431 and the p+ conductive glue 441 pass through the center of the n+ auxiliary gate partition region 4200 , and the n+ conductive wire 432 and the n+ conductive glue 442 pass through the center of the p+ auxiliary gate partition region 4100 .

[0048] When the number of p+ auxiliary gates 41 disposed on the single p+ segment is greater than or equal to 2, the two ends of the multiple p+ sub-auxiliary gates 411 parallel to each other in the single p+ segment are connected via an anti-breaking gate 412; when the number of n+ auxiliary gates 42 disposed on the single n+ segment is greater than or equal to 2, the two ends of the multiple n+ sub-auxiliary gates 421 parallel to each other in the single p+ segment are connected via an anti-breaking gate 422. Figure 1 As shown, in this embodiment, two p+ sub-gates 41 are arranged on the single p+ section, and both ends of the two p+ sub-gates 411 are connected by an anti-break gate 412 .

[0049] The conductive wire 43 is made of a copper welding strip or an aluminum welding strip. The conductive adhesive is selected from a low-resistivity thermosetting material, and mainly includes a polymer matrix, a conductive filler, a curing agent / initiator / catalyst and an additive. The polymer matrix includes an acrylic system, an epoxy system, a silicone system, etc. The conductive filler includes silver, silver-coated copper, gold and nickel, etc. The resistivity of the conductive adhesive is required to be less than 0.00001Ω.cm; the width of the conductive adhesive can be set to 100μm, 200μm, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm or any other value between 100 and 800μm, such as Figure 3 As shown, the present embodiment adopts a width of 600 μm, and the widths of the p+ auxiliary gate partition region 4100 and the n+ auxiliary gate partition region 4200 are both 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1000 μm, 1100 μm, 1200 μm, 1300 μm, 1400 μm, 1500 μm or any other value between 500 and 1500 μm, such as Figure 3 As shown, the width of the present embodiment is 1000 μm, and the widths of the two satisfy that: the width of the conductive glue is 400 μm smaller than the width of the p+ auxiliary gate partition region or the n+ auxiliary gate partition region. Example

[0050] This embodiment proposes an electrode structure and a battery assembly of an interdigitated back-contact battery, wherein the interdigitated back-contact battery 4 includes a crystalline silicon substrate, a front passivation layer and a front anti-reflection layer, p+ regions and n+ regions alternately arranged on the back surface of the crystalline silicon substrate, a back insulating passivation layer, and an electrode structure.

[0051] The p+ region is composed of a plurality of p+ segments, and the n+ region is composed of a plurality of n+ segments.

[0052] The electrode structure adopts a main grid-free design, such as Figure 1 As shown, there is only a sub-gate, which includes multiple p+ sub-gates 41 and multiple n+ sub-gates 42. The p+ sub-gate 41 is set on the p+ region passivation film, and the n+ sub-gate 42 is set on the n+ region passivation layer. The p+ sub-gate 41 and the n+ sub-gate 42 are arranged alternately. According to the design requirements of different numbers of p+ sub-gates 41 and n+ sub-gates 42, a corresponding number of p+ sub-gates 41 are set on a single p+ segment, and a corresponding number of n+ sub-gates 42 are set on a single n+ segment. The number of sub-gates is 162.

[0053] The battery components are as follows Figure 6 As shown, glass 1, glass fiber 2, POE film / EVA film 3, battery string C (multiple interdigitated back-contact battery cells 4), POE film / EVA film 5, and glass / back plate 6 are sequentially laid from top to bottom, and prepared through processes such as lamination, trimming, framing, and wiring to obtain a battery assembly.

[0054] The battery string C is Figure 4 , 5 As shown, it includes a plurality of interdigitated back contact battery sheets 4, a plurality of conductive wires 43, a plurality of conductive glues and a plurality of bus bars.

[0055] The plurality of interdigital back-contact batteries 4 include a first battery cell, a second battery cell ... a Cth battery cell,

[0056] The conductive wire 43, such as Figure 1 , 2 As shown, it includes a p+ conductive wire 431 and an n+ conductive wire 432. The p+ conductive wire 431 is vertically connected to the p+ sub-gate 41 through a p+ conductive glue 441, and is discontinuously not connected to the n+ sub-gate 42. The n+ conductive wire 432 is vertically connected to the n+ sub-gate 42 through an n+ conductive glue 442, and is discontinuously not connected to the p+ sub-gate 41. The p+ conductive wire 431 and the n+ conductive wire 432 are arranged alternately, and the number of conductive wires is 22.

[0057] The busbar, such as Figure 5As shown, it is arranged on the upper and lower sides of the module, including a first bus 451, a second bus 452 and a third bus 453. The first bus 451 and the second bus 452 are used to collect current and export it to the external circuit, and the third bus 453 is used for current transmission between adjacent battery strings in the middle. The first bus 451 is connected to the p+ conductive line 431, the second bus 452 is connected to the n+ conductive line 432, and the third bus 453 is connected to the n+ conductive line 432 and the p+ conductive line 431 of two adjacent battery cells.

[0058] The battery layer of the battery module is arranged according to the formula C=A×B, where A represents the number of battery strings, B represents the number of battery cells in a single battery string, and C represents the number of all battery cells in the module. Figure 5As shown, in this embodiment, the battery string C is 24 pieces, the number of battery groups A is 4 groups, and the number of single-string batteries B is 6 pieces; the battery string is assembled in a manner that after the p+ conductive wire 431 of the first battery piece is connected to the first bus 451, the second battery piece is rotated 180° in the horizontal plane, and the left and right edges of the two batteries are aligned, so that the p+ conductive wire 431 on the second battery piece and the n+ conductive wire 432 on the first battery piece are in a straight line, and the p+ conductive wire 431 of the second battery piece and the n+ conductive wire 432 of the first battery piece are connected to each other Then place the third cell normally, so that the p+ conductive line 431 on the third cell is in a straight line with the n+ conductive line 432 of the second cell, and the p+ conductive line 431 of the third cell is connected to the n+ conductive line 432 of the second cell, and repeat the above operation until the sixth cell is placed, so that the p+ conductive line 431 of the sixth cell is connected to the n+ conductive line 432 of the fifth cell, and the n+ conductive line 432 of the sixth cell is connected to the third bus 453, and the single battery string B is completed. Continue to connect the second battery string in series, place the seventh battery cell normally, align it with the upper and lower edges of the sixth battery cell, connect the p+ conductive wire 431 of the seventh battery cell to the third bus 453, rotate the eighth battery cell 180° on the horizontal plane, make the p+ conductive wire 431 on the eighth battery cell and the n+ conductive wire 432 of the seventh battery cell in a straight line, and make the p+ conductive wire 431 of the eighth battery cell and the n+ conductive wire 432 of the seventh battery cell connected to each other, then place the ninth battery cell normally, so that the p+ conductive wire 431 on the ninth battery cell is aligned with the n+ conductive wire 432 on the seventh battery cell. The p+ conductive wire 431 of the eighth cell is in a straight line with the n+ conductive wire 432 of the eighth cell, and the p+ conductive wire 431 of the ninth cell is connected to the n+ conductive wire 432 of the eighth cell, and the above operation is repeated until the twenty-fourth cell is placed, so that the p+ conductive wire 431 of the twenty-fourth cell is connected to the n+ conductive wire 432 of the twenty-third cell, and the n+ conductive wire 432 of the twenty-fourth cell is connected to the second bus 452, completing the 4×6 arrangement of the battery string structure to form a 24-cell solar cell group.

[0059] The interdigitated back contact cell 4 is an N-type crystalline silicon cell. The number of p+ auxiliary gates 41 and the number of n+ auxiliary gates 42 are set, and the relationship between the two satisfies the following formula: the number of p+ auxiliary gates 41: the number of n+ auxiliary gates 42 = 1.33, 1.5, 2. In this embodiment, the number of p+ auxiliary gates 41 is 108, and the number of n+ auxiliary gates 42 is 54.

[0060] The p+ sub-gate 41 is composed of a plurality of p+ sub-gates 411 arranged at intervals, and a p+ sub-gate isolation region 4100 is set between two adjacent p+ sub-gates 411; the n+ sub-gate 42 is composed of a plurality of n+ sub-gates 421 arranged at intervals, and an n+ sub-gate isolation region 4200 is set between two adjacent n+ sub-gates 421; the p+ sub-gate isolation regions 4100 of adjacent p+ sub-gates 41 and the n+ sub-gate isolation regions 4200 of adjacent n+ sub-gates 42 are staggered.

[0061] The p+ conductive wire 431 and the p+ conductive glue 441 pass through the center of the n+ auxiliary gate partition region 4200 , and the n+ conductive wire 432 and the n+ conductive glue 442 pass through the center of the p+ auxiliary gate partition region 4100 .

[0062] When the number of p+ auxiliary gates 41 disposed on the single p+ segment is greater than or equal to 2, the two ends of the multiple p+ sub-auxiliary gates 411 parallel to each other in the single p+ segment are connected via an anti-breaking gate 412; when the number of n+ auxiliary gates 42 disposed on the single n+ segment is greater than or equal to 2, the two ends of the multiple n+ sub-auxiliary gates 421 parallel to each other in the single p+ segment are connected via an anti-breaking gate 422. Figure 1 As shown, in this embodiment, two p+ sub-gates 41 are arranged on the single p+ section, and both ends of the two p+ sub-gates 411 are connected by an anti-break gate 412 .

[0063] The conductive wire 43 is made of a copper welding strip or an aluminum welding strip. The conductive adhesive is selected from a low-resistivity thermosetting material, mainly including a polymer matrix, a conductive filler, a curing agent / initiator / catalyst and an additive. The polymer matrix includes an acrylic system, an epoxy system, a silicone system, etc. The conductive filler includes silver, silver-coated copper, gold and nickel, etc. The resistivity of the conductive adhesive is required to be less than 0.00001Ω.cm. The width of the conductive wire 43 and the conductive adhesive can be set to 100μm, 200μm, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm or any other value between 100 and 800μm, such as Figure 3 As shown, the present embodiment adopts a width of 800 μm, and the widths of the p+ auxiliary gate partition region 4100 and the n+ auxiliary gate partition region 4200 are both 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1000 μm, 1100 μm, 1200 μm, 1300 μm, 1400 μm, 1500 μm or any other value between 500 and 1500 μm, such as Figure 3 As shown, the width of the present embodiment is 1400 μm, and the widths of the two satisfy that: the width of the conductive glue is 600 μm smaller than the width of the p+ auxiliary gate partition region or the n+ auxiliary gate partition region.

[0064] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes may be made to it in form and detail without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A battery assembly, characterized in that: It includes upper glass, glass fiber, upper POE film or EVA film, battery string, lower POE film or EVA film, and lower glass laid sequentially from top to bottom; The battery string includes a plurality of conductive wires, a plurality of conductive adhesives, a plurality of bus bars, and a plurality of interdigitated back-contact battery sheets; The interdigitated back contact cell comprises a crystalline silicon substrate, the back surface of which forms p+ regions and n+ regions arranged alternately; the p+ region is composed of a plurality of p+ segments; the n+ region is composed of a plurality of n+ segments; A p+ region passivation film is disposed on a single p+ segment, and a predetermined number of p+ sub-gates are arranged on the p+ region passivation film; an n+ region passivation film is disposed on a single n+ segment, and a predetermined number of n+ sub-gates are arranged on the n+ region passivation film; The p+ sub-gates and the n+ sub-gates are arranged alternately; The conductive wires include p+ conductive wires and n+ conductive wires, wherein the p+ conductive wires are vertically connected to the p+ auxiliary grid through conductive glue and are discontinuously connected to the n+ auxiliary grid; The n+ conductive wire is vertically connected to the n+ auxiliary grid through a conductive glue, and is discontinuously connected to the p+ auxiliary grid; The p+ conductive wires and the n+ conductive wires are arranged alternately; The busbars include a first busbar, a second busbar and a third busbar; the first busbar and the second busbar are used to collect current and export it to an external circuit; the third busbar is used to transfer current between adjacent battery strings in the middle in the horizontal or vertical direction; The first bus is connected to the p+ conductive line, the second bus is connected to the n+ conductive line, and the third bus is connected to the n+ conductive line and the p+ conductive line of two adjacent interdigital back contact battery cells; The interdigitated back contact cell is any one of a P-type crystalline silicon cell and an N-type crystalline silicon cell; The relationship between the p+ sub-gate and the n+ sub-gate satisfies the following formula: When the interdigitated back contact cell is of P type, the number of n+ sub-gates is ≥ 1.3 times the number of p+ sub-gates, and the number of n+ sub-gates set on a single n+ segment satisfies: 5>the number of n+ sub-gates is ≥ 2; When the interdigitated back contact battery is of N type, the number of p+ sub-gates is ≥ 1.3 times the number of n+ sub-gates, and the number of p+ sub-gates set on a single p+ segment satisfies: 5>the number of p+ sub-gates is ≥2.

2. The battery assembly according to claim 1, characterized in that: The p+ sub-gate is formed by a plurality of p+ sub-gates arranged at intervals, and a p+ sub-gate isolating region is provided between two adjacent p+ sub-gates; the n+ sub-gate is formed by a plurality of n+ sub-gates arranged at intervals, and an n+ sub-gate isolating region is provided between two adjacent n+ sub-gates; the p+ sub-gate isolating regions of adjacent p+ sub-gates and the n+ sub-gate isolating regions of adjacent n+ sub-gates are staggered; The p+ conductive wire and conductive glue pass through the center of the n+ auxiliary gate partition area, and the n+ conductive wire and conductive glue pass through the center of the p+ auxiliary gate partition area.

3. The battery assembly according to claim 1, characterized in that: When the number of the p+ sub-gates arranged on a single p+ segment is greater than or equal to 2, the two ends of the multiple p+ sub-gates parallel to the upper and lower portions of the single p+ segment are connected via an anti-breaking gate; when the number of the n+ sub-gates arranged on a single n+ segment is greater than or equal to 2, the two ends of the multiple n+ sub-gates parallel to the upper and lower portions of the single p+ segment are connected via an anti-breaking gate.

4. The battery assembly according to claim 1, characterized in that: The conductive wire is made of copper welding strip or aluminum welding strip; the width of the conductive wire is smaller than the width of the conductive glue; the width of the conductive wire and the conductive glue is smaller than the width of the p+ auxiliary gate partition area and the n+ auxiliary gate partition area.

5. The battery assembly according to claim 1, characterized in that: The widths of the p+ auxiliary gate partition region, the n+ auxiliary gate partition region, and the conductive adhesive meet the following conditions: p+ auxiliary gate isolation area = n+ auxiliary gate isolation area ≥ conductive glue width + 400μm.

6. The battery assembly according to claim 1, characterized in that: The arrangement of the battery layers of the battery assembly satisfies the relationship C=A×B; Where A represents the number of battery strings, B represents the number of cells in a single battery string, and C represents the number of all cells in the module. When B=1, C=B=A=1; when B>1, 216≥C≥B>A≥1.

7. The battery assembly according to claim 6, when the number of battery cells in a single battery string is greater than 1, is characterized in that: The battery assembly is assembled using the following assembly steps: S1. After connecting the p+ conductive wire of the first battery cell to the first bus bar, rotate the second battery cell 180° in the horizontal plane, align the edges of the two batteries, make the p+ conductive wire on the second battery cell and the n+ conductive wire on the first battery cell in a straight line, and connect the p+ conductive wire of the second battery cell to the n+ conductive wire of the first battery cell; S2, placing the third battery cell so that the p+ conductive line on the third battery cell and the n+ conductive line of the second battery cell are in a straight line, and the p+ conductive line of the third battery cell and the n+ conductive line of the second battery cell are connected to each other; S3. Repeat steps S1 to S2 until the Bth battery cell is placed, so that the p+ conductive wire of the Bth battery cell is connected to the n+ conductive wire of the B-1th battery cell, and the n+ conductive wire of the Bth battery cell is connected to the second bus or the third bus to form a battery string structure.

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