MAIN-GATE-FREE AND HIGH-EFFICIENCY BACK-CONTACT SOLAR CELL MODULE, MAIN-GATE-FREE AND HIGH-EFFICIENCY BACK-CONTACT SOLAR CELL ASSEMBLY, AND PREPARATION PROCESS THEREOF

• US 20170222082A1
• Filed: 03/23/2015
• Published: 08/03/2017
• Est. Priority Date: 09/28/2014
• Status: Active Grant

• Current Assignee: Jolywood (Suzhou) Sunwatt Co., Ltd.
• Original Assignee: Jolywood (Suzhou) Sunwatt Co., Ltd.
• Inventors: LIN, Jianwei, XIA, Wenjin, SUN, Yuhai, ZHANG, Yuzheng
• Granted Patent: US 10,593,822 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 31/0201 comprising specially adapted module bus-bar structures
• CPC Class Codes: H01L 31/02167 for solar cells
• CPC Class Codes: H01L 31/022441 Electrode arrangements specially adapted for back-contact solar cells
• CPC Class Codes: H01L 31/0481 characterised by the composition of the encapsulation material
• CPC Class Codes: H01L 31/0512 made of a particular material or composition of materials
• CPC Class Codes: H01L 31/0516 specially adapted for interconnection of back-contact solar cells
• CPC Class Codes: H01L 31/1864 Annealing
• CPC Class Codes: H01L 31/1876 Particular processes or apparatus for batch treatment of the devices
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

The present invention relates to the field of solar cells, and in particular to a main-gate-free and high-efficiency back-contact solar cell module, a main-gate-free and high-efficiency back-contact solar cell assembly, and a preparation process thereof. The solar cell module, comprising cells and an electrical connection layer, a backlight side of the cells having P-electrodes connected to a P-type doping layer and N-electrodes connected to a N-type doping layer, is characterized in that the electrical connection layer comprises a number of parallel leads each electrically connected to the P-electrodes or the N-electrodes. The present invention has the beneficial effect that a main-gate-free and high-efficiency back-contact solar cell module, a main-gate-free and high-efficiency back-contact solar cell assembly, and a preparation process thereof are provided, which can effectively the short-circuiting of the P-electrodes and the N-electrodes and has the advantages of low cost, high hidden-cracking resistance, high efficiency and high stability.

Claims

1. A main-gate-free and high-efficiency back-contact solar cell module, comprising cells and an electrical connection layer, a backlight side of the cells having P-electrodes connected to a P-type doping layer and N-electrodes connected to a N-type doping layer, characterized in that the electrical connection layer comprises a number of parallel leads each electrically connected to the P-electrodes or the N-electrodes.

2. The main-gate-free and high-efficiency back-contact solar cell module according to claim 1, characterized in that the P-electrodes are dotted P-electrodes or linear P-electrodes, and the N-electrodes are dotted N-electrodes or linear N-electrodes.

3. The main-gate-free and high-efficiency back-contact solar cell module according to claim 2, characterized in that the diameter of the dotted P-electrodes is 0.4 mm to 1.5 mm, the distance between two adjacent dotted P-electrodes connected to a same one of the leads is 0.7 mm to 10 mm, and the width of the linear P-electrodes is 0.4 mm to 1.5 mm;

and the diameter of the dotted N-electrodes is 0.4 mm to 1.5 mm, the distance between two adjacent dotted N-electrodes connected to a same one of the leads is 0.7 mm to 10 mm, and the width of the linear N-electrodes is 0.4 mm to 1.5 mm.

4. The main-gate-free and high-efficiency back-contact solar cell module according to claim 2, characterized in that the total number of the dotted P-electrodes and the dotted N-electrodes is 1000 to 40000.

5. The main-gate-free and high-efficiency back-contact solar cell module according to claim 2, characterized in that the dotted electrodes or linear electrodes are made of any one of silver paste, conductive adhesive, conductive polymeric material or tin solder.

6. The main-gate-free and high-efficiency back-contact solar cell module according to claim 1, characterized in that the distance between a lead connected to the P-electrodes and a lead connected to the N-electrodes is 0.1 mm to 20 mm.

7. The main-gate-free and high-efficiency back-contact solar cell module according to claim 1, characterized in that the lead is made of any one or more of copper, aluminum, steel, copper clad aluminum or copper clad steel;

the cross-section of the lead is any one or more of a circular shape, a square shape or an elliptical shape; and

the diameter of a circumcircle of the cross-section shape of the lead is 0.05 mm to 1.5 mm.

8. The main-gate-free and high-efficiency back-contact solar cell module according to claim 1, characterized in that the surface of the lead is plated with anti-oxidation plating material or coated with a conductive adhesive.

9. The main-gate-free and high-efficiency back-contact solar cell module according to claim 8, characterized in that the anti-oxidation plating material is any one of tin, tin-lead alloy, tin-bismuth alloy or tin-lead-silver alloy;

and the thickness of the plating layer or conductive adhesive layer of the lead is 5 μ

m to 50 μ

m.

10. The main-gate-free and high-efficiency back-contact solar cell module according to claim 8, characterized in that the conductive adhesive is a low-resistivity conductive adhesive that uses a conductive particle and a polymeric binder as main components.

11. The main-gate-free and high-efficiency back-contact solar cell module according to claim 10, characterized in that the conductive particle in the conductive adhesive is any one or more of gold, silver, copper, god-plated nickel, silver-plated nickel and silver-plated copper;

and the shape of the conductive particle is any one or more of a spherical shape, a flake shape, an olivary shape and an acicular shape; and

the particle size of the conductive particle is 0.01 μ

m to 5 μ

m.

12. The main-gate-free and high-efficiency back-contact solar cell module according to claim 10, characterized in that the polymeric binder in the conductive adhesive is any one of or a combination of two of epoxy resin, polyurethane resin, acrylic resin or organic silicone resin, and the binder is thermosetting or photocureable.

13. The main-gate-free and high-efficiency back-contact solar cell module according to claim 1, characterized in that the number of the leads is 10 to 500.

14. The main-gate-free and high-efficiency back-contact solar cell module according to claim 1, characterized in that the electrical connection layer is provided with P-busbar electrodes and N-busbar electrodes, which are arranged on two sides of the electrical connection layer.

15. The main-gate-free and high-efficiency back-contact solar cell module according to claim 14, characterized in that the surface of the busbar electrodes has a concave-convex shape.

16. The main-gate-free and high-efficiency back-contact solar cell module according to claim 1, characterized in that a thermoplastic resin or thermosetting resin is provided at an insulating layer between the P-electrodes and the N-electrodes.

17. The main-gate-free and high-efficiency back-contact solar cell module according to claim 16, characterized in that the resin is any one of or a combination of two of ethylene-vinyl acetate copolymer, polyolefin resin, epoxy resin, polyurethane resin, acrylic resin and organic silicon resin.

18. A main-gate-free and high-efficiency back-contact solar cell assembly, comprising fronting material, packaging material, a solar cell layer, packaging material and backing material, which are connected from top to bottom, characterized in that the solar cell layer comprises a number of solar cell modules, the solar cell module refers to the solar cell module according to any one of claims 1-17, and the adjacent ones of the solar cell modules are electrically connected via busbars located on two sides of an electrical connection layer.

19. The main-gate-free and high-efficiency back-contact solar cell assembly according to claim 18, characterized in that solar cells in each of the solar cell modules are connected in series to each other;

and the solar cell modules are successively connected in series to each other, and the number of solar cells in each of the solar cell modules is the same.

20. The main-gate-free and high-efficiency back-contact solar cell assembly according to claim 18, characterized in that the number of cells in the solar cell layer is 1 to 120, wherein the solar cell layer comprises 1 to 120 cell modules and each of the cell modules comprises 1 to 120 cells.

21. The main-gate-free and high-efficiency back-contact solar cell assembly according to claim 18, characterized in that the busbars are connected by a conductive medium.

22. The main-gate-free and high-efficiency back-contact solar cell assembly according to claim 21, characterized in that the conductive medium comprises any one of silver paste, conductive adhesive or tin solder.

23. A method for preparing a main-gate-free and high-efficiency back-contact solar cell assembly, comprising the following steps:

step 1 of preparing solar cell modules;

straightening and tightening a number of parallel leads, and electrically connecting each of the leads to P-electrodes and N-electrodes located on the back of a cell;

disposing the P-busbar electrodes and the N-busbar electrodes on two sides of an electrical connection layer to prepare solar cell modules;

step 2 of preparing a solar cell layer;

electrically connecting the solar cell modules prepared in the step 1 by busbar electrodes to prepare a solar cell layer; and

step 3 of successively stacking and laminating fronting material, packaging material, a solar cell layer, packaging material and backing material to obtain a cell assembly.

24. The method for preparing a main-gate-free and high-efficiency back-contact solar cell assembly according to claim 23, characterized in that the P-electrodes and the N-electrodes on the cell in the step 1 have a mirror-symmetric structure in a horizontal plane;

and when the number of cells is greater than 1, the cells are assembled in such a manner that, after the first cell is connected to the electrical connection layer, the second cell is rotated by 180°

in the horizontal plane and edges of the two cells are aligned to each other so that the P-electrodes on the second cell and the N-electrodes on the first cell are on a same lead, and then the third back-contact cell is placed normally so that the P-electrodes on the third cell and the N-electrodes on the second cell are on a same lead; and

the above operations are repeated to form a serial connection structure and a solar cell layer is thus formed.

25. The method for preparing a main-gate-free and high-efficiency back-contact solar cell assembly according to claim 23, characterized in that parameters for the laminating operation are set according to the vulcanizing properties of the packaging material;

and the packaging material is EVA and the parameters for the laminating operation are as follows;

laminating for 16 min at 145°

C.

26. The method for preparing a main-gate-free and high-efficiency back-contact solar cell assembly according to claim 23, characterized in that the cell and the lead in the step 1 are electrically connected by coating conductive adhesive on a P-type doping layer and a N-type doping layer on a cell by screen printing;

the conductive adhesive, when heated, can be solidified to form the P-electrodes and the N-electrodes; and

when heated, the lead and the P-electrodes or the N-electrodes come into Ohm contact by the conductive adhesive, and in this way, the lead and the cell are electrically connected;

the cell and the lead are also electrically connected by plating low-melting-point material on the lead by a plating process;

when heated, the lead and the P-type doping layer or the N-type doping layer are welded by the melting of the low-melting-point material to form the P-electrodes and the N-electrodes, and in this way the lead and the cell are electrically connected; and

the low-melting-point material is any one of tin solder, tin-lead alloy, tin-bismuth alloy or tin-lead-silver alloy.

27. The method for preparing a main-gate-free and high-efficiency back-contact solar cell assembly according to claim 26, characterized in that, in the heating process, a heating pad is used on a front side of the cell;

and the heating temperature of the heating pad is 40°

C. to 80°

C.

28. The method for preparing a main-gate-free and high-efficiency back-contact solar cell assembly according to claim 26, characterized in that the way of heating is any one or more of infrared radiation, heating by resistance wires or heating by hot wind;

and the heating temperature is 150°

C. to 500°

C.

29. The method for preparing a main-gate-free and high-efficiency back-contact solar cell assembly according to claim 26, characterized in that the plating process is any one of hot dipping, electroplating or chemical plating.