Back contact stacked gate structure battery piece and battery

Abstract

The utility model discloses a back contact stacked gate structure battery piece and a battery, which belong to the technical field of solar cells, and comprise a battery piece, at least one positive electrode and at least one negative electrode, the positive electrode and the negative electrode are distributed on the back surface of the battery piece in a staggered manner, stacked gate structures are arranged on the positive electrode and the negative electrode, and each stacked gate structure comprises a current collection layer and a conductive wire. The current collection layers are arranged on the positive electrode and the negative electrode, the conductive wires cover the current collection layers in an overlapped mode, the back face of the cell piece is free of grid lines, the grid lines are prevented from collecting and transmitting current in a dense arrangement mode of the overlapped grid structures, the thickness of the current collection layers is reduced, silver consumption is greatly reduced, and the cell cost is reduced. The photo-generated current on the surface of the battery piece is collected by the current collection layer and directly transmitted to the conductive wire, a transmission path of the current on the auxiliary grid is omitted, the current transmission path is short, the resistance loss is low, and the battery efficiency is high.

Description

Technical Field

[0001] The utility model belongs to the technical field of solar cells, in particular to a back contact stacked grid structure cell sheet and a battery. Background Art

[0002] The back contact battery transfers the front electrode to the back, and the positive and negative electrodes are staggered on the back. There are sub-grids on the positive and negative electrodes. All positive sub-grids are collected on the positive main grid, and all negative sub-grids are collected on the negative main grid. The main grid is perpendicular to the sub-grid, and the number of main grids is generally 2 to 20.

[0003] The gate wire material is mainly silver, which accounts for about half of the non-silicon cost of the battery. The gate wire plays the role of collecting and transmitting current. In particular, the lateral current transmission path requires the resistance to be as small as possible, so the cross-sectional area of ​​the gate wire must be increased accordingly, and the corresponding silver consumption will increase significantly, so the battery cost is high;

[0004] Since the back-contact battery transfers the front electrode to the back, the back side shading increases significantly, so the battery bifaciality drops significantly. Currently, the bifaciality of the back-contact battery is about 50%, which is much lower than the 80% of the conventional double-sided electrode structure battery. Utility Model Content

[0005] Purpose of the utility model: to provide a back-contact stacked-grid structure cell and battery to solve the above-mentioned problems existing in the prior art.

[0006] Technical solution: A back-contact stacked-grid structure cell, comprising a cell, at least one positive electrode, and at least one negative electrode, wherein the positive electrode and the negative electrode are alternately distributed on the back of the cell;

[0007] The positive electrode and the negative electrode are provided with a stacked grid structure, and the stacked grid structure includes a current collecting layer and a conductive wire. The current collecting layer is arranged on the positive electrode and the negative electrode, and the conductive wire is superimposed and covered on the current collecting layer.

[0008] Preferably, the current collecting layer is a continuous or segmented grid line structure.

[0009] Preferably, the current collection layer has a width of 0.01 mm to 0.1 mm, a height of 1 μm to 20 μm, and a spacing of 0.5 mm to 2 mm.

[0010] Preferably, the width of the positive electrode and the negative electrode is 0.2 mm to 1 mm.

[0011] Preferably, the cross-sectional shape of the conductive wire is a plane geometric shape.

[0012] Preferably, a conductive connecting material is provided between the current collecting layer and the conductive wire.

[0013] Preferably, it also includes a conductive connecting strip, and the conductive connecting strip is arranged on the back of the battery cell;

[0014] The conductive connecting strip connects the conductive wires connected to the same electrode in series and separates them from the conductive wires connected to another electrode by an insulating material.

[0015] The utility model also provides a back-contact stacked-grid structure battery, comprising at least two battery cells described in any one of the above items, wherein the positive electrodes and negative electrodes of two adjacent battery cells are connected via a conductive wire.

[0016] Preferably, a second conductive connecting bar is provided in the interval between two adjacent battery cells, and the second conductive connecting bar connects the conductive wires connected to the same electrode in series.

[0017] In summary, the beneficial effects of the utility model are:

[0018] 1. There is no grid line on the back of the battery cell. The grid line is used to collect and transmit current through the dense stacked grid structure, and the thickness of the current collection layer is thinned, which greatly reduces the silver consumption and reduces the battery cost.

[0019] 2. The photocurrent on the surface of the solar cell is collected by the current collection layer and directly transmitted to the conductive wire, eliminating the current transmission path on the secondary grid. The current transmission path is short, the resistance loss is low, and the battery efficiency is high.

[0020] 3. The cross-section of the conductive wire is a plane geometric shape with high reflectivity, which can reflect the light projected onto the conductive wire to the surface of the battery cell for use, reduce the actual shading on the back side, and improve the battery bifaciality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of a back-contact stacked-grid structure cell provided by the utility model;

[0022] Figure 2 This is a back view of a back-contact stacked-grid structure cell provided by the utility model;

[0023] Figure 3 It is a schematic diagram of a back-contact stacked-grid structure battery provided by the utility model.

[0024] The figures are marked as follows: 1. battery cell; 2. current collecting layer; 3. conductive wire; 4. conductive connecting material; 5. first conductive connecting strip; 6. insulating material; 7. second conductive connecting strip. DETAILED DESCRIPTION

[0025] In the following description, a large number of specific details are given to provide a more thorough understanding of the utility model. However, it is obvious to those skilled in the art that the utility model can be implemented without one or more of these details. In other examples, in order to avoid confusion with the utility model, some technical features known in the art are not described. Example 1

[0026] like Figure 1 As shown, the back-contact stacked-grid structure cell disclosed in this embodiment includes a cell 1, at least one positive electrode, and at least one negative electrode. The positive electrode and the negative electrode are alternately distributed on the back of the cell 1, and a stacked-grid structure is provided on the positive electrode and the negative electrode. The stacked-grid structure includes a current collecting layer 2 and a conductive wire 3. The current collecting layer 2 is arranged on the positive electrode and the negative electrode, and the conductive wire 3 is superimposed and covered on the current collecting layer 2. There is no grid line on the back of the cell 1. The grid line is used to eliminate current collection and transmission by the densely arranged stacked-grid structure, and the thickness of the current collecting layer 2 is thinned, which greatly reduces the silver consumption and reduces the battery cost. The photogenerated current on the surface of the cell 1 is collected by the current collecting layer 2 and directly transmitted to the conductive wire 3, eliminating the current transmission path on the auxiliary grid. The current transmission path is short, the resistance loss is low, and the battery efficiency is high.

[0027] like Figure 1 As shown, the current collection layer 2 is a continuous or segmented grid line structure. Both structures can realize current collection and transmission. When the current collection layer 2 adopts a segmented grid line structure, the silver consumption can be further reduced.

[0028] like Figure 1 As shown, the current collection layer 2 has a width of 0.01 mm to 0.1 mm, a height of 1 μm to 20 μm, and a spacing of 0.5 mm to 2 mm.

[0029] like Figure 1 As shown, the width of the positive electrode and the negative electrode is 0.2mm~1mm.

[0030] like Figure 1 As shown, the cross-sectional shape of the conductive wire 3 is a plane geometric shape, and the cross-sectional shape of the conductive wire 3 can be a triangle, a circle, a semicircle, or a trapezoid. The cross-sectional shape of the conductive wire 3 is a plane geometric shape, and has a high reflectivity. The light projected onto the conductive wire 3 can be reflected to the surface of the battery cell 1 for utilization, thereby reducing actual shading on the back side and improving the battery bifaciality.

[0031] like Figure 1 As shown, a conductive connecting material 4 is provided between the current collecting layer 2 and the conductive wire 3 to improve the stability of the connection between the current collecting layer 2 and the conductive wire 3 . Example 2

[0032] like Figure 2As shown, the difference from Example 1 is that the back-contact stacked-grid structure cell disclosed in this embodiment also includes a first conductive connecting strip 5, which is arranged on the back of the cell 1. The first conductive connecting strip 5 connects the conductive wires 3 connected to the same electrode in series and is separated from the conductive wire 3 connected to the other electrode by an insulating material 6.

[0033] This is because each positive or negative electrode area is independent of each other, and the current on each conductive wire 3 is also independent of each other. There are certain differences in the photoelectric conversion capacity of each area in the battery cell 1, resulting in certain differences in the current between the conductive wires 3 and the inability to flow between them to achieve balance. When the battery cells 1 are connected in series, the current mismatch loss between the battery cells 1 will be greatly increased, thereby reducing the power generation efficiency of the battery cell 1.

[0034] Therefore, in this embodiment, the conductive wires 3 connected to the same electrode are connected in series through the first conductive connecting strip 5, so as to realize the free flow of current between the conductive wires 3, make the current on each conductive wire 3 consistent, reduce the current mismatch loss between the battery cells 1, and improve the power generation efficiency of the battery cell 1. At the same time, the first conductive connecting strip 5 is separated from the conductive wire 3 connected to the other electrode by the insulating material 6 to prevent short circuit. Example 3

[0035] like Figure 3 As shown, the back-contact stacked-grid structure battery disclosed in this embodiment includes at least two battery cells 1 in Embodiment 1, and the positive electrodes and negative electrodes of two adjacent battery cells 1 are connected by a conductive wire 3.

[0036] like Figure 3 As shown, a second conductive connecting bar 7 is provided in the interval between two adjacent battery cells 1 , and the second conductive connecting bar 7 connects the conductive wires 3 connected to the same electrode in series.

[0037] The second conductive connecting strip 7 in this embodiment plays the same role as the first conductive connecting strip 5 in the second embodiment.

[0038] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings; however, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical scheme of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. A back contact stacked grid structure cell, characterized in that: It comprises a battery cell (1), at least one positive electrode, and at least one negative electrode, wherein the positive electrode and the negative electrode are alternately distributed on the back of the battery cell (1); The positive electrode and the negative electrode are provided with a stacked grid structure, the stacked grid structure comprising a current collection layer (2) and a conductive wire (3), the current collection layer (2) being provided on the positive electrode and the negative electrode, and the conductive wire (3) being superimposed and covered on the current collection layer (2).

2. The back contact stacked grid structure cell according to claim 1, characterized in that: The current collecting layer (2) is a continuous or segmented grid line structure.

3. The back contact stacked grid structure cell according to claim 1, characterized in that: The current collecting layer (2) has a width of 0.01 mm to 0.1 mm, a height of 1 μm to 20 μm, and a spacing of 0.5 mm to 2 mm.

4. The back contact stacked grid structure cell according to claim 1, characterized in that: The width of the positive electrode and the negative electrode is 0.2mm~1mm.

5. The back contact stacked grid structure cell according to claim 1, characterized in that: The cross-sectional shape of the conductive wire (3) is a plane geometric shape.

6. The back contact stacked grid structure cell according to claim 1, characterized in that: A conductive connecting material (4) is provided between the current collecting layer (2) and the conductive wire (3).

7. The back contact stacked grid structure cell according to claim 1, characterized in that: It also comprises a first conductive connecting strip (5), wherein the first conductive connecting strip (5) is arranged on the back side of the battery cell (1); The first conductive connecting strip (5) connects the conductive wires (3) connected to the same electrode in series, and is separated from the conductive wires (3) connected to another electrode by an insulating material (6).

8. A back contact stacked grid structure battery, characterized in that: It comprises at least two battery cells (1) according to any one of claims 1 to 7, wherein the positive electrodes and negative electrodes of two adjacent battery cells (1) are connected via a conductive wire (3).

9. The back contact stacked grid structure battery according to claim 8, characterized in that: A second conductive connecting strip (7) is provided in the interval between two adjacent battery sheets (1), and the second conductive connecting strip (7) connects the conductive wires (3) connected to the same electrode in series.

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