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CN-224205546-U - Back contact battery, back contact laminated battery and photovoltaic module

CN224205546UCN 224205546 UCN224205546 UCN 224205546UCN-224205546-U

Abstract

The application provides a back contact battery, a back contact laminated battery and a photovoltaic module, which comprise a substrate and grid lines, wherein the grid lines comprise first grid lines, the first grid lines are arranged along a first direction, welding parts are arranged on the first grid lines, each welding part comprises a plurality of first welding parts and second welding parts, the second welding parts are positioned at two opposite ends of the first grid lines along the length direction of the first grid lines, the first welding parts are positioned between the two second welding parts, the size of each second welding part is larger than that of each first welding part along the length direction of the first grid lines, and the area of each first welding part is gradually increased along the direction close to each second welding part. The first grid line is responsible for transmitting current, and the second welding part outputs current, so that the larger the current is near the second welding part, the smaller the resistance of the first welding part with larger area is, the larger the current carrying capacity is, and the loss in the current transmission process can be reduced and the power generation efficiency is improved by increasing the area of the first welding part along the direction near the second welding part.

Inventors

  • WANG LUCHUANG
  • PENG YINGYING
  • FANG SHENG

Assignees

  • 晶科能源(海宁)有限公司

Dates

Publication Date
20260505
Application Date
20250610

Claims (12)

  1. 1. A back contact battery, comprising: A substrate (171); a gate line (172), the gate line (172) being disposed on the substrate (171); Wherein the grid line (172) comprises a first grid line (1721), the first grid line (1721) is arranged along a first direction (X), the first grid line (1721) is provided with welding parts (173), the welding parts (173) comprise a plurality of first welding parts (1731) and two second welding parts (1732), the second welding parts (1732) are positioned at two opposite ends of the first grid line (1721) along the length direction of the first grid line (1721), and the first welding parts (1731) are positioned between the two second welding parts (1732); the second welding portion (1732) has a larger size than the first welding portion (1731) along a length direction of the first gate line (1721), and the first welding portion (1731) has an area gradually increasing along a direction approaching the second welding portion (1732).
  2. 2. The back contact battery of claim 1, wherein at least one of said first welds (1731) has a dimension in the second direction (Y) that is greater than a dimension of said second welds (1732).
  3. 3. The back contact battery of claim 1, wherein a dimensional difference C between adjacent first solder portions (1731) along the second direction (Y) is satisfied, 0.008mm C0.015 mm.
  4. 4. The back contact battery of claim 3, wherein the dimensions of adjacent first welds (1731) vary equally along the second direction (Y).
  5. 5. The back contact battery of claim 1, wherein the first weld (1731) has a minimum dimension L1 in the second direction (Y), and the first weld (1731) has a maximum dimension L2 in the second direction (Y); l2 is more than or equal to 0.6mm and less than or equal to 1.4mm, and 0.2mm L1 is more than or equal to 0.6mm, and/or; the ratio of the L2 to the L1 is 1.5-7 and L2 is 1-7.
  6. 6. The back contact battery of claim 1, wherein the number of first welds (1731) is 3 to 80.
  7. 7. The back contact battery of any one of claims 1 to 6, wherein the first grid line (1721) comprises a first connection section (1721 a) and a second connection section (1721 b), the first connection section (1721 a) being located at a side of the second weld (1732) remote from the first weld (1731), the second connection section (1721 b) being for connecting the first weld (1731) and the second weld (1732) or the adjacent first weld (1731); The width of the first connecting section (1721 a) gradually decreases in a direction away from the second welding portion (1732).
  8. 8. The back contact battery of claim 7, wherein the first connecting section (1721 a) has a width L3 at an end proximate to the second weld (1732) and a width L4 at an end distal to the second weld (1732); L3 is more than or equal to 0.15mm and less than or equal to 0.35mm, and 0.05mm L4 is more than or equal to 0.25mm, and/or; the ratio of L3 to L4 is 1.2-L3 and L4-L5.
  9. 9. The back contact battery of claim 7, wherein the gate line (172) includes a plurality of second gate lines (1722), the second gate lines (1722) extending along a second direction (Y) and being arranged at intervals along a first direction (X), the second gate lines (1722) being electrically connected to the first gate lines (1721) or the solder (173); The second gate line (1722) on a side of the second welding portion (1732) away from the first welding portion (1731) gradually increases in size in a second direction (Y) in a direction away from the second welding portion (1732).
  10. 10. The back contact battery of any one of claims 1 to 6, wherein the gate line (172) includes a plurality of second gate lines (1722), the second gate lines (1722) extend along a second direction (Y) and are arranged along a first direction (X), the second gate lines (1722) are electrically connected to the first gate lines (1721) or the solder portion (173), the second gate lines (1722) located at the most edge position of the substrate (171) are edge gate lines (1722 a), the remaining second gate lines (1722) are middle gate lines (1722 b), the edge gate lines (1722 a) are continuous structures, and the middle gate lines (1722 b) are disconnected at the first gate line (1721) positions with different polarities; The first gate line (1721) having the same polarity as the edge gate line (1722 a) is electrically connected to the edge gate line (1722 a), and the first gate line (1721) having a different polarity from the edge gate line (1722 a) is connected to the edge gate line (1722 a) or not connected to the edge gate line (1722 a) through an insulating paste.
  11. 11. A back contact laminate cell, characterized in that the back contact laminate cell comprises a top cell and a bottom cell connected to each other, the top cell being a perovskite cell (18) and the bottom cell being a back contact cell (17), wherein the back contact cell (17) is a back contact cell (17) according to any one of claims 1 to 10.
  12. 12. A photovoltaic module characterized in that it comprises at least one cell string comprising the back-contact cell (17) of any one of claims 1 to 10 or the back-contact laminate cell (1) of claim 11.

Description

Back contact battery, back contact laminated battery and photovoltaic module Technical Field The application relates to the technical field of photovoltaic modules, in particular to a back contact battery, a back contact laminated battery and a photovoltaic module. Background The BC battery is called back contact battery, its basic type is IBC battery (cross finger type back contact battery), the biggest difference with other crystal silicon battery route is that emitter, surface field and metal electrode are all made in the battery back, and cross finger type distributes, and the battery front surface does not have any grid line to shelter from, furthest utilizes incident light, reduces optical loss, brings more effective power generation area, but back contact battery is great in the electric current collection process loss for battery piece efficiency reduces. Disclosure of utility model The application provides a back contact battery, a back contact laminated battery and a photovoltaic module, the back contact battery can improve the efficiency of the photovoltaic module and reduce the loss during current transmission. The application provides a back contact battery, which comprises a substrate, a grid line, a first electrode and a second electrode, wherein the grid line is arranged on the substrate, the grid line comprises a first grid line, the first grid line is arranged along a first direction, the first grid line is provided with a welding part, the welding part comprises a plurality of first welding parts and two second welding parts, the second welding parts are positioned at two opposite ends of the first grid line along the length direction of the first grid line, and the first welding parts are positioned between the two second welding parts; The size of the second welding part is larger than that of the first welding part along the length direction of the first grid line, and the area of the first welding part gradually increases along the direction close to the second welding part. In this scheme, the first grid line is used as the main grid line of the back contact battery, the second welding part is used for transmitting current to the output end of the back contact battery, and the collected current is output through the second welding part, so that the current at the position closer to the second welding part is larger. According to the law of resistance formula r=ρl/S, where R is the resistance value, ρ is the resistivity of the material, L is the length of the conductor, and S is the cross-sectional area of the conductor. The larger the cross-sectional area S of the conductor, the smaller the resistance R, as known from the formula. I.e. the larger the area of the weld, the smaller its resistance. Therefore, the size of the second welding part is larger than that of the first welding part, the area of the first welding part is gradually increased along the direction close to the second welding part, namely, the resistance of the first welding part is smaller as the area is closer to the second welding part, the loss of current conducted to the second welding part through each first welding part can be reduced by reducing the resistance, and the working efficiency of the back contact battery is improved. And the second welding parts positioned at the two ends of the first grid line are of larger size, so that the connection strength of the edge area of the first grid line and the connection stability of the first grid line and the welding strip can be obviously enhanced, the buckling deformation risk caused by heat generated in the power generation process of the back contact battery is effectively reduced, and the working stability and reliability of the back contact battery are ensured. Meanwhile, the area of the first welding part close to the second welding part is gradually increased, the welding area of the first welding part and the welding strip can be increased, the risks of cold joint and welding leakage are reduced, and therefore the connection effect of the first welding part at the end part and the back contact battery is improved, and the performance of the back contact battery is improved. In one possible design, the dimensions of at least one of the first welds are larger than the dimensions of the second welds in the second direction. In the scheme, the size of at least one first welding part is larger than that of a second welding part along the second direction, and the current conduction capacity of the end part of the first grid line can be obviously improved along the first grid line along the direction close to the second welding part due to the fact that the current on the first grid line is increased along the direction close to the second welding part, the current carrying requirement of a high current density area is met, the reliability of current conduction at the position close to the second welding part is ensured, meanwhile, the mechanical support strengt