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CN-121985629-A - Back contact solar cell and photovoltaic module

CN121985629ACN 121985629 ACN121985629 ACN 121985629ACN-121985629-A

Abstract

The invention discloses a back contact solar cell and a photovoltaic module, relates to the technical field of photovoltaics, and is used for improving the insulation characteristic of an insulation structure and reducing the leakage risk of the back contact solar cell. The back contact solar cell includes a cell body, a first collector electrode disposed on a back surface of the cell body, a second collector electrode, and an insulating structure. The first collector electrode and the second collector electrode are opposite in conductivity type. The first collector electrodes and the second collector electrodes extend in the first direction and are alternately arranged at intervals in the second direction. The insulation structure is arranged on a part of the area of the first collector electrode and a part of the area of the second collector electrode. The insulating structure on the first collector electrode is staggered with the insulating structure on the second collector electrode along the first direction. The insulating structure includes a carrier resin and a filler at least partially disposed within the carrier resin. The ratio between the largest one of the three-dimensional dimensions of at least part of the filler and the smallest one is greater than 3.

Inventors

  • HE BO
  • FANG LIANG
  • XU XIXIANG
  • WANG MINGKUI
  • DONG XIN
  • LI PENG

Assignees

  • 隆基绿能科技股份有限公司西咸新区分公司

Dates

Publication Date
20260505
Application Date
20251226

Claims (19)

  1. 1. The back contact solar cell is characterized by comprising a cell body, a first collecting electrode, a second collecting electrode and an insulating structure, wherein the first collecting electrode, the second collecting electrode and the insulating structure are arranged on the back surface of the cell body; the first collector electrode and the second collector electrode extend along a first direction and are alternately arranged at intervals along a second direction, and the first direction is intersected with the second direction; The insulation structure is arranged on a part of the area of the first collector electrode and a part of the area of the second collector electrode, the insulation structure positioned on the first collector electrode and the insulation structure positioned on the second collector electrode are staggered along the first direction, the insulation structure comprises carrier resin and filler at least partially positioned in the carrier resin, and the ratio of the largest one of the three-dimensional dimensions of at least part of the filler to the smallest one of the three-dimensional dimensions of the filler is larger than 3.
  2. 2. The back contact solar cell of claim 1, wherein at least a portion of the filler is in the form of a sheet, rod, thorn, dendrite, or fiber; And/or, at least a part of the filler has a largest one of three-dimensional dimensions of 50nm or more and 5 μm or less.
  3. 3. The back contact solar cell of claim 1, wherein the filler is an inorganic filler comprising at least one of boron nitride, silica, mica powder, talc, alumina, calcium carbonate, quartz powder, barium sulfate, aluminum nitride, silicon nitride, magnesium oxide, zinc oxide, boron nitride, ceramic powder, and glass powder; And/or the thermal decomposition temperature of the insulating structure is less than 300 ℃, and/or the volume resistivity of the insulating structure is greater than 10 12 Ω -m.
  4. 4. The back contact solar cell according to claim 1, wherein a ratio between a thickness of the insulating structure and a width of the insulating structure is 0.01 or more and 1 or less, wherein a thickness direction of the insulating structure is parallel to a thickness direction of the cell body, and a width direction of the insulating structure is parallel to the first direction; The thickness of the insulating structure in the thickness direction of the battery body is 10 μm or more and 50 μm or less.
  5. 5. The back contact solar cell of claim 4, wherein a breakdown voltage of said insulating structure is 140 kv per millimeter or more.
  6. 6. The back contact solar cell of claim 1, wherein the insulating structure is a photo-cured insulating structure.
  7. 7. The back contact solar cell of claim 1, wherein the carrier resin comprises at least one of epoxy modified polyacrylic acid, glycidyl ether modified acrylate, glycidyl esters, aliphatic epoxy modified acrylate, phenolic modified epoxy, bisphenol a modified epoxy, and bisphenol F modified epoxy.
  8. 8. The back contact solar cell of claim 1, wherein the insulating structure has a glass transition temperature of 140 ℃ or more and 200 ℃ or less.
  9. 9. The back contact solar cell of claim 1, wherein the material of the first collector electrode and/or the second collector electrode comprises a base metal.
  10. 10. The back contact solar cell of claim 1 or 9, further comprising a first bus electrode and a second bus electrode, the first bus electrode and the second bus electrode extending along the second direction and alternately spaced apart along the first direction, the first bus electrode electrically connected to at least a portion of the first collector electrode, the second bus electrode electrically connected to at least a portion of the second collector electrode; the insulating structure is located between the first collecting electrode and the second collecting electrode, and between the second collecting electrode and the first collecting electrode.
  11. 11. The back contact solar cell of claim 10, wherein the material of the first and/or second bus electrode comprises a base metal.
  12. 12. The back contact solar cell of claim 10, wherein in the first direction, the first and/or second bus electrode comprises a main body portion, and organic expansion portions located on both sides of the main body portion; The surface roughness of the organic extension on the insulating structure is greater than the surface roughness of the insulating structure exposed outside the organic extension.
  13. 13. The back contact solar cell according to claim 1, further comprising an organic connection layer between the insulating structure and the first collector electrode and/or the second collector electrode, wherein the material of the organic connection layer is the same as the material of the carrier resin.
  14. 14. The back contact solar cell of claim 13, wherein the thickness of the organic connection layer is 0.1 μm or more and 1 μm or less.
  15. 15. The back contact solar cell according to claim 1, wherein the insulating structure is connected to the first collector electrode and/or the second collector electrode at least by chemical bonds.
  16. 16. The back contact solar cell of claim 15, wherein the material of the carrier resin comprises acidic groups therein; And/or the material of the carrier resin comprises at least one of an acrylic group, a carboxylic acid group and a phosphoric acid group.
  17. 17. A photovoltaic module, comprising: A battery string comprising a plurality of back contact solar cells as claimed in any one of claims 1 to 16 and a plurality of solder strips through which adjacent back contact solar cells are electrically connected; And an encapsulation layer covering a surface of the battery string.
  18. 18. The photovoltaic assembly of claim 17, wherein the solder strip is electrically connected to the first collector electrode comprised by one of the two adjacent back contact solar cells and to the second collector electrode comprised by the other.
  19. 19. The photovoltaic module according to claim 17, wherein in the case where the back contact solar cell is the back contact solar cell of claim 10, the solder ribbon is electrically connected to the first bus electrode included in one of the adjacent two back contact solar cells and to the second bus electrode included in the other.

Description

Back contact solar cell and photovoltaic module Technical Field The invention relates to the technical field of photovoltaics, in particular to a back contact solar cell and a photovoltaic module. Background In recent years, due to global warming and continuous improvement of living standard of people, the demand for clean energy is increased, and the photovoltaic power generation occupies the largest proportion in the clean energy, so that the solar energy generation device has the advantages of high efficiency, small pollution, simple installation, high safety and the like, and is favored by countries around the world. The installed quantity is far ahead. The technology of solar cells is also advancing, and the highest efficiency breaks through the world records. The back contact solar cell is a solar cell in which the front surface (namely, the light directly irradiated surface) of the cell is electrodeless, and both the positive electrode and the negative electrode are arranged on one side of the back surface of the cell, so that shielding of the electrode to the cell can be reduced, short-circuit current of the cell is increased, and energy conversion efficiency of the cell is improved. In addition, the back side of the back contact solar cell is typically provided with an insulating structure to isolate the opposite conductivity type positive and negative electrodes from each other, preventing shorting. However, the insulation characteristics of the insulation structure in the existing back contact solar cell are poor, so that the leakage risk of the back contact solar cell is high, and the improvement of the working performance of the back contact solar cell is not facilitated. Disclosure of Invention The invention aims to provide a back contact solar cell and a photovoltaic module, which are used for improving the insulation characteristic of an insulation structure, reducing the leakage risk of the back contact solar cell and being beneficial to ensuring that the back contact solar cell has higher working performance. In order to achieve the above object, in a first aspect, the present invention provides a back contact solar cell including a cell body, and a first collector electrode, a second collector electrode, and an insulating structure disposed on a back surface of the cell body. The first collector electrode and the second collector electrode are opposite in conductivity type. The first collector electrodes and the second collector electrodes extend in the first direction and are alternately arranged at intervals in the second direction. The first direction intersects the second direction. The insulation structure is arranged on a part of the area of the first collector electrode and a part of the area of the second collector electrode. The insulating structure on the first collector electrode is staggered with the insulating structure on the second collector electrode along the first direction. The insulating structure includes a carrier resin and a filler at least partially disposed within the carrier resin. The ratio between the largest one of the three-dimensional dimensions of at least part of the filler and the smallest one is greater than 3. With the above technical solution, the insulating structure provided on the partial region of the first collector electrode and the partial region of the second collector electrode includes a carrier resin. In the actual process of printing the insulating structure, the viscosity of the carrier resin is relatively low so as to prevent the problem that bubbles are difficult to discharge in the curing process of the insulating structure, and the problems that the insulating property of the insulating structure is poor, the light transmittance of the insulating structure is reduced due to the fact that more bubbles exist in the insulating structure, and the bubbles are blocked by the bubbles to generate heat of the battery and the like are avoided, so that the yield of the back contact solar cell is improved. In addition, the insulating structure includes a filler material located at least partially within the carrier resin. The carrier resin itself has a certain fluidity due to its relatively low viscosity, so that it is easily spread before curing, resulting in its small thickness. And solid filler is added into carrier resin with certain fluidity, so that the fluidity of the carrier resin is reduced. Based on this, in the present invention, the ratio between the largest one and the smallest one of the three-dimensional dimensions of at least part of the filler is larger than 3, when the filler is not a regular shape which is approximately the same in size in different directions like a sphere and is easy to roll, because of the special size design of the filler, the biggest one of the three-dimensional dimensions has larger binding effect on the carrier resin, the fluidity of the whole insulation structure can be reduced, the whole viscosity of th