0BB heterojunction double-sided battery and assembly

Abstract

The utility model relates to the technical field of 0BB batteries, in particular to an 0BB heterojunction double-sided battery and component, which comprises a battery piece, main grid line metal electrodes are not arranged on the front surface and the back surface of the battery piece, a plurality of fine grid electrodes are respectively arranged on the front surface and the back surface of the battery piece, a plurality of common welding spots are arranged on the fine grid electrodes, and the common welding spots are welded on the front surface and the back surface of the battery piece. One end of the battery piece is provided with a first thickened welding spot, and the other end of the battery piece is provided with a harpoon grid line. A common welding spot is located in the middle of the battery piece, and the welding strip is small in external swing force and not prone to falling off. The welding strips at the harpoon grid lines enable the battery pieces to be interconnected, the welding strips bear large external acting force in the transmission process and are prone to falling off, the harpoon grid lines are arranged, the influence of external swinging force on the welding strips is reduced, the buffering effect is achieved, meanwhile, the collecting grid line current can be increased, and the welding strips at the two ends can be prevented from falling off through cooperation of the harpoon grid lines and the first thickened welding points.

Description

Technical Field

[0001] The utility model relates to the technical field of 0BB batteries, and in particular to a 0BB heterojunction double-sided battery and a component. Background Art

[0002] The prior art uses three schemes for heterojunction 0BB battery interconnection. The first is the SmartWire scheme, which first produces an organic film (copper wire composite film) with an embedded circular copper welding strip, connects the battery cells in series, and then realizes the alloying of the welding strip and the battery cell through lamination. This scheme does not require a stringer for high-temperature welding, but this scheme requires an additional layer of composite film, which has problems such as high cost and patent protection, so the large-scale promotion of busbar-free technology has not been achieved in China; the second scheme is the glue dispensing scheme, which first applies UV glue, uses UV lamp to glue and solidify the entire welding strip on the battery cell, and then realizes the alloying of the welding strip and the battery cell through lamination. This scheme is different from the welding glue dispensing scheme in that no welding is required, and glue dispensing can be achieved to fix it, but this scheme has high requirements on the glue film, and needs to use low-flow glue film performance, and the glue film needs to be heated on both sides during the lamination stage, and uses a low-temperature welding strip with a melting point of about 120°C. The welding strip has a low melting point and a high risk of hot spots. The third solution is welding + dispensing or dispensing + welding process, which uses infrared heating to melt the alloy or metal on the surface of the welding strip and complete the initial connection with the surface of the battery cell and the fine grid;

[0003] Adhesion points are applied at the designated positions of the welded cell-welding strips, and solidified at the same time to form a battery string. This solution has high reliability, and alloy contact has been formed during the stringing machine, which can clearly detect the EL before the layer, avoiding the risk of batch quality problems at the subsequent component end; using medium-temperature welding strips, it is not affected by hot spots; no special integrated film or skin film is required, and no cost is increased.

[0004] However, since the battery cell has no main grid, the welding method is used, which increases the difficulty of welding. In order to ensure that each fine grid electrode can be welded, over-welding may occur if the welding temperature or power is increased. In particular, when silver-clad copper electrodes are used, over-welding will cause the silver coating to melt, resulting in exposed copper particles. Once exposed, the copper particles are easily oxidized or corroded by trace amounts of oxygen, water vapor, and organic acids in the component, resulting in attenuation of battery efficiency and component power. In severe cases, it may cause failure of various components in the component.

[0005] Therefore, how to achieve reliable welding on silver-clad copper 0BB battery cells and avoid the welding ribbon from falling off is a problem that technical personnel in this field urgently need to solve. Utility Model Content

[0006] The purpose of the utility model is to provide a 0BB heterojunction bifacial battery and assembly, so as to solve the technical problem in the prior art of how to achieve reliable welding on silver-clad copper 0BB battery sheets and avoid the falling off of the welding strip.

[0007] The utility model discloses a 0BB heterojunction double-sided battery, comprising a battery cell, wherein the front and back sides of the battery cell are both without main grid metal electrodes, the front and back sides of the battery cell are respectively provided with a plurality of fine grid electrodes, the fine grid electrodes are provided with a plurality of common welding points, one end of the battery cell is provided with a first thickened welding point, and the other end of the battery cell is provided with a harpoon grid line.

[0008] Working principle: The common welding point is in the middle of the battery cell, and the welding ribbon is less affected by the external swing force and is not easily affected by falling off. The welding ribbon at the harpoon grid line will interconnect the battery cells, and is subject to greater external forces during transmission, and is easy to fall off. By setting the harpoon grid line, the welding ribbon is less affected by the external swing force, which plays a buffering role. At the same time, it can increase the collection grid line current. In combination with the first thickened welding point, it can prevent the welding ribbons at both ends from falling off.

[0009] Furthermore, the harpoon gate line is a short gate line spanning across a plurality of fine gate electrodes.

[0010] By providing a short gate line, a fine gate electrode at one end of the battery cell can be connected to a fine gate electrode in the middle, thereby improving the stability of the connection.

[0011] Furthermore, each of the harpoon wires includes two short wires, and the length of the short wires is 3-5 mm.

[0012] Furthermore, the two short gate lines form a trapezoidal structure, and the upper bottom of the trapezoidal structure is close to one side of the first thickened welding point.

[0013] Furthermore, a second thickened welding point is provided on the upper bottom of the trapezoidal structure.

[0014] Furthermore, the second thickened welding point is the upper bottom of the trapezoidal structure.

[0015] Furthermore, the bottom of the trapezoidal structure is a gap formed by two short grid lines at the fine grid electrode at the end of the battery cell, and the width of the gap is 0.3-0.6 mm.

[0016] Furthermore, the first thickened welding spot and the second thickened welding spot are wider than the ordinary welding spot.

[0017] Furthermore, the common solder joint has a length of 1-3 mm and a width of 0.6-1.2 mm, and the first thickened solder joint and the second thickened solder joint have a length of 1-2 mm and a width of 1-2 mm.

[0018] Further, the common thickened solder joint, the first thickened solder joint and the second thickened solder joint in the same horizontal direction are connected by solder strips.

[0019] Furthermore, the common thickened solder joint, the first thickened solder joint and the second thickened solder joint are all pure silver solder joints.

[0020] Furthermore, the fine gate electrode is a silver-clad copper electrode.

[0021] Furthermore, the number of fine grid electrodes on the back side of the cell is greater than the number of fine grid electrodes on the front side.

[0022] Furthermore, the number of fine grid electrodes on the front side of the cell is 1.2-3 times the number of fine grid electrodes on the back side. Preferably, the number of fine grid electrodes on the front side of the cell is 50-60, and the number of fine grid electrodes on the back side of the cell is 100-120.

[0023] Furthermore, the width of the fine grid electrode on the front side of the cell is smaller than that of the fine grid electrode on the back side, the width of the front electrode is 10-30um, and the width of the back electrode is 20-40um, which can improve the conversion efficiency of the front cell and the power generation capacity of the front side of the component.

[0024] A 0BB ​​heterojunction bifacial battery assembly is composed of the above-mentioned 0BB heterojunction bifacial battery.

[0025] Furthermore, adjacent batteries in the battery assembly are connected by welding ribbons.

[0026] Furthermore, the welding ribbon connects the second thickened welding point of the previous battery and the battery cell of the next battery, or the welding ribbon connects the battery cell of the previous battery and the battery cell of the next battery.

[0027] Compared with the prior art, the utility model has the following beneficial effects:

[0028] 1. By setting the harpoon grid line, the influence of external swing force on the welding strip is reduced, which plays a buffering role. At the same time, the collection grid line current can be increased. In combination with the first thickened welding point, the welding strips at both ends can be prevented from falling off;

[0029] 2. By setting a short gate line, the fine gate electrode at one end of the battery cell can be connected to the fine gate electrode in the middle, thereby improving the stability of the connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 This is a schematic diagram of the battery cell structure of the utility model.

[0032] Figure 2 This is a schematic diagram of the battery assembly structure of the utility model.

[0033] In the above drawings, the meanings of the various marks are: 1-battery cell, 2-fine grid electrode, 3-ordinary welding point, 4-first thickened welding point, 5-harpoon grid line, 6-short grid line, 7-second thickened welding point, 8-welding strip. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0035] Example 1

[0036] The technical solutions adopted in this embodiment are as follows:

[0037] like Figure 1-Figure 2 As shown, a 0BB heterojunction bifacial battery includes a battery cell 1, wherein the battery cell 1 has no main grid metal electrode on the front and back sides, and the battery cell 1 is respectively provided with a plurality of fine grid electrodes 2 on the front and back sides, and a plurality of ordinary welding points 3 are provided on the fine grid electrodes 2, a first thickened welding point 4 is provided at one end of the battery cell 1, and a harpoon grid line 5 is provided at the other end of the battery cell 1.

[0038] Working principle: the common welding point 3 is in the middle of the battery cell 1, and the welding strip 8 is less affected by the external swing force and is not easily affected by falling off. The welding strip 8 at the harpoon grid line 5 will interconnect the battery cell 1 with the battery cell 1. During the transmission process, it is affected by a large external force and is easy to fall off. By setting the harpoon grid line 5, the welding strip 8 is less affected by the external swing force, which plays a buffering role. At the same time, the collection grid line current can be increased. In combination with the first thickened welding point 4, the welding strips 8 at both ends can be prevented from falling off.

[0039] Example 2

[0040] In this embodiment, as a preferred embodiment of the present utility model, the specific structure is as follows Figure 1-Figure 2 As shown, it discloses the following improvement on the basis of implementation mode 1, the harpoon gate line 5 is a short gate line 6 spanning multiple fine gate electrodes 2, each of the harpoon gate lines 5 includes two short gate lines 6, the short gate line 6 is 3-5mm long, and the two short gate lines 6 form a trapezoidal structure, the upper bottom of the trapezoidal structure is close to one side of the first thickened weld point 4, the upper bottom of the trapezoidal structure is provided with a second thickened weld point 7, the second thickened weld point 7 is the upper bottom of the trapezoidal structure, and the lower bottom of the trapezoidal structure is the vacancy formed by the two short gate lines 6 in the fine gate electrode 2 at the end of the battery cell 1, and the width of the vacancy is 0.3-0.6mm.

[0041] By providing the short gate line 6 , the fine gate electrode 2 at one end of the battery cell 1 can be connected to the fine gate electrode 2 in the middle, thereby improving the stability of the connection.

[0042] Example 3

[0043] In this embodiment as a preferred embodiment of the utility model, it discloses the following improvements based on embodiment 2: the width of the first thickened solder joint 4 and the second thickened solder joint 7 is greater than that of the ordinary solder joint 3, the length of the ordinary solder joint 3 is 1-3mm, the width is 0.6-1.2mm, the length of the first thickened solder joint 4 and the second thickened solder joint 7 is 1-2mm, the width is 1-2mm, the ordinary thickened solder joint, the first thickened solder joint 4 and the second thickened solder joint 7 in the same horizontal direction are connected by a solder strip 8, the ordinary thickened solder joint, the first thickened solder joint 4 and the second thickened solder joint 7 are all pure silver solder joints, and the fine gate electrode 2 is a silver-clad copper electrode.

[0044] Example 4

[0045] In this embodiment as a preferred embodiment of the utility model, it discloses the following improvements based on embodiment 3: the number of fine grid electrodes 2 on the back side of the battery cell 1 is greater than the number of fine grid electrodes 2 on the front side, and the number of fine grid electrodes 2 on the front side of the battery cell 1 is 1.2-3 times the number of fine grid electrodes 2 on the back side. Preferably, the number of fine grid electrodes 2 on the front side of the battery cell 1 is 50-60, and the number of fine grid electrodes 2 on the back side of the battery cell 1 is 100-120. The width of the fine grid electrode 2 on the front side of the battery cell 1 is smaller than the width of the fine grid electrode 2 on the back side. The width of the front electrode is 10-30um, and the width of the back electrode is 20-40um, which can improve the conversion efficiency of the front battery cell 1 and the power generation power of the front side of the component.

[0046] Example 5

[0047] In this embodiment, as a preferred embodiment of the utility model, a 0BB heterojunction double-sided battery assembly is disclosed, and the specific structure is as follows Figure 2 As shown, a 0BB heterojunction bifacial battery is formed through the embodiment 4, and adjacent batteries in the battery assembly are connected by welding ribbon 8, and the welding ribbon 8 connects the second thickened welding point 7 of the previous battery and the battery cell 1 of the next battery, or the welding ribbon 8 connects the battery cell of the previous battery and the battery cell of the next battery.

[0048] The above are the implementation methods listed in this embodiment, but this embodiment is not limited to the above optional implementation methods. Those skilled in the art can arbitrarily combine the above methods to obtain other various implementation methods. Anyone can derive other various forms of implementation methods under the inspiration of this embodiment. The above specific implementation methods should not be understood as limiting the scope of protection of this embodiment. The scope of protection of this embodiment shall be based on the definition in the claims, and the description can be used to interpret the claims.

Claims

1. A 0BB ​​heterojunction bifacial battery, comprising a battery cell (1), characterized in that: The front and back sides of the cell (1) do not have main grid metal electrodes; the front and back sides of the cell (1) are respectively provided with a plurality of fine grid electrodes (2); the fine grid electrodes (2) are provided with a plurality of common welding points (3); one end of the cell (1) is provided with a first thickened welding point (4); and the other end of the cell (1) is provided with a harpoon grid line (5).

2. The 0BB heterojunction bifacial battery according to claim 1, characterized in that: The harpoon grid line (5) is a short grid line (6) that crosses a plurality of fine grid electrodes (2).

3. The 0BB heterojunction bifacial battery according to claim 2, characterized in that: Each of the harpoon grid lines (5) comprises two short grid lines (6), and the length of the short grid lines (6) is 3-5 mm.

4. The 0BB heterojunction bifacial battery according to claim 3, characterized in that: The two short gate lines (6) form a trapezoidal structure, and the upper base of the trapezoidal structure is close to one side of the first thickened welding point (4).

5. The 0BB heterojunction bifacial battery according to claim 4, characterized in that: The upper bottom of the trapezoidal structure is provided with a second thickened welding point (7).

6. The 0BB heterojunction bifacial battery according to claim 5, characterized in that: The first thickened welding spot (4) and the second thickened welding spot (7) are wider than the ordinary welding spot (3).

7. The 0BB heterojunction bifacial battery according to claim 4, characterized in that: The bottom of the trapezoidal structure is a gap formed by two short grid lines (6) at the end of the fine grid electrode (2) of the battery cell (1), and the width of the gap is 0.3-0.6 mm.

8. The 0BB heterojunction bifacial battery according to claim 1, characterized in that: The number of fine grid electrodes (2) on the back side of the battery cell (1) is greater than the number of fine grid electrodes (2) on the front side.

9. A 0BB ​​heterojunction bifacial battery assembly, characterized in that: A 0BB ​​heterojunction bifacial battery comprising any one of claims 1 to 8.

10. The 0BB heterojunction bifacial battery assembly according to claim 9, characterized in that: Adjacent batteries in the battery assembly are connected via welding strips (8).

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