A method for repairing hidden grid lines of a battery cell

Abstract

The present invention discloses a method for repairing grid line defects of a cell, and relates to the technical field of solar cells. A method for repairing grid line defects of a cell comprises the following steps: subjecting a cell with grid line defects to sintering, light injection and laser-assisted sintering treatments in sequence. The present invention can achieve a repair rate of grid line defects of more than 60% without significant loss of photoelectric conversion efficiency by subjecting the cell to sintering, light injection and laser-assisted sintering treatments. This may be because irregular cracks are filled and connected by the slurry of the cell after sintering, light injection and laser-assisted sintering treatments, thereby improving the adhesion of the cracks in the cell and repairing the grid line defects.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a method for repairing grid line failure of a solar cell. Background Art

[0002] With the rise in energy prices, the development and utilization of new energy has become a major research topic in the energy field today. Since solar energy has the advantages of being pollution-free, not geographically restricted, and inexhaustible, research on solar power generation has become the main direction for the development and utilization of new energy. Using solar cells to generate electricity is a major way for people to use solar energy today. Traditional solar cells have a main grid structure with electrodes on both sides, especially the main grid of the front electrode, which will block part of the sunlight and reduce the overall conversion efficiency of the cell. In addition, the traditional main grid is welded with welding ribbons. Once the components have hidden cracks, the overall efficiency of the components will decrease rapidly, and even cause the components to fail completely or be scrapped. Hidden cell grid refers to irregular hidden cracks at the grid of the cell. When the hidden cracks cause the grid to break, the current cannot be effectively collected, resulting in partial or even complete failure of the cell. It may also cause fragments, hot spots, etc., and cause power attenuation of the component.

[0003] The main reasons for the hidden grid lines are material defects or process problems during the manufacturing process. In order to avoid the hidden grid lines of the battery cells, the quality control and detection during the production process are generally strengthened to avoid the hidden grid lines. Once the battery cells have hidden grid lines, they can only be scrapped or downgraded, resulting in economic losses. However, there is a lack of remedial measures for hidden grid lines in the prior art, which makes a large number of battery cells waste due to scrapping. Therefore, it is urgent to provide a method for repairing hidden grid lines of battery cells, so as to avoid the scrapping or downgrading of battery cells due to hidden grid lines. Summary of the invention

[0004] The technical problem to be solved by the present invention is that there is a lack of remedial measures for gate line failure in the prior art, resulting in a waste of resources. The purpose is to provide a method for repairing gate line failure of a cell, thereby avoiding the scrapping or downgrading of the cell due to gate line failure.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for repairing a grid line failure of a battery cell comprises the following steps:

[0007] The cell with hidden grid lines is sequentially subjected to sintering, light injection and laser-assisted sintering processes.

[0008] As a possible design, the above-mentioned battery cell is also dried before sintering.

[0009] As a possible design, the drying treatment temperature is 350-450°C.

[0010] As a possible design, the above sintering is specifically to place the battery cell in a sintering furnace for sintering. During sintering, the temperature of the upper temperature zone is 450-510°C, and the temperature of the lower temperature zone is 420-480°C.

[0011] As a possible design, during the above sintering, the battery cells are placed on a conveyor belt, and the sintering belt speed is 1.8 to 3.8 m / min.

[0012] As a possible design, the above-mentioned light injection annealing treatment is divided into 5 temperature zones, the temperature of temperature zone 1 is 600-640°C, the temperature of temperature zone 2 is 600-640°C, the temperature of temperature zone 3 is 550-600°C, the temperature of temperature zone 4 is 540-580°C, and the temperature of temperature zone 5 is 520-560°C.

[0013] As a possible design, during the above light injection, the cell is placed on a conveyor belt and passes through five temperature zones in sequence at a belt speed of 1.8 to 3.8 m / min, and then cooled.

[0014] As a possible design, the irradiation power of the above light injection is 90%.

[0015] As a possible design, the deflection voltage of the above laser-assisted sintering is -13 to -19 V, and the power is 17%.

[0016] As a possible design, the above cell was also checked by EL test (electroluminescence test) after laser assisted sintering process.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] The present invention can achieve a repair rate of grid line type failure of more than 60% without significant loss of photoelectric conversion efficiency by subjecting the cell to sintering, light injection and laser assisted sintering. This may be due to the reconstruction of the material structure of the cell crack after sintering, light injection and laser assisted sintering, thereby repairing the grid line type failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0020] Figure 1 EL comparison diagram of the cell gate before (left) and after (right) repair according to Example 1 of the present invention. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0022] A method for repairing a grid line failure of a battery cell comprises the following steps:

[0023] The cell with hidden grid lines is sequentially subjected to sintering, light injection and laser-assisted sintering processes.

[0024] The present invention can achieve a repair rate of over 60% for grid line type hidden defects without significant loss of photoelectric conversion efficiency by subjecting the cell to sintering, light injection and laser assisted sintering treatments. This may be because irregular hidden cracks are filled and connected by the slurry of the cell after sintering, light injection and laser assisted sintering treatments, which improves the adhesion of the cell hidden cracks, thereby repairing grid line type hidden defects.

[0025] Preferably, the cells are subjected to an EL test before processing to select cells with hidden gate lines.

[0026] As a possible design, the battery cell is dried before sintering. After the slurry on the battery cell is dried, the organic matter in the slurry will be volatilized and the slurry will be changed from a solid-liquid mixed state to a solid state.

[0027] Preferably, the drying and sintering of the battery cells are both carried out in a roller sintering furnace.

[0028] As a possible design, the drying treatment temperature is 350-450° C., and the drying is carried out on a conveyor belt with a drying belt speed of 1.8-3.8 m / min.

[0029] At this belt speed, the battery cells can be fully dried while ensuring a certain repair efficiency.

[0030] As a possible design, the above sintering is specifically to place the battery cell in a sintering furnace for sintering. During sintering, the temperature of the upper temperature zone is 450-510°C, and the temperature of the lower temperature zone is 420-480°C.

[0031] By sintering, the slurry can form a good ohmic contact with the silicon substrate, so that a low-resistance contact interface is formed between the silicon wafer and the slurry, which is beneficial to the input and output of current and improves the overall performance of the device. In addition, sintering at this temperature can improve the bonding strength between the slurry and the battery cell. At the same time, the inventor speculates that sintering at this temperature may play a certain role in repairing irregular hidden cracks in the battery cell.

[0032] As a possible design, the battery cell is placed on a conveyor belt during the sintering process, and the sintering belt speed is 1.8-3.8 m / min. Sintering at this speed can ensure full contact between the slurry and the battery cell, thereby improving the ohmic contact effect.

[0033] As a possible design, the above-mentioned light injection annealing treatment is divided into 5 temperature zones, and the battery cell will pass through 5 temperature zones in turn. The temperature of temperature zone 1 is 600-640℃, the temperature of temperature zone 2 is 600-640℃, the temperature of temperature zone 3 is 550-600℃, the temperature of temperature zone 4 is 540-580℃, and the temperature of temperature zone 5 is 520-560℃. Hydrogen passivation can be achieved by zoning the light injection treatment of the battery. H atoms in the silicon nitride passivation film are activated by annealing; irradiation controls the valence state of H atoms so that they combine with the recombination center (defect) at the P+ emitter and the N-type substrate to form a non-recombination center. Finally, a good passivation effect is achieved to achieve the purpose of improving Voc and FF, so the overall effect of light injection annealing + irradiation is to play a role in hydrogen passivation.

[0034] As a possible design, during the above light injection, the cell is placed on a conveyor belt and passes through five temperature zones in sequence at a belt speed of 1.8 to 3.8 m / min, and then cooled.

[0035] As a possible design, the irradiation power of the above light injection is 90% of the maximum power.

[0036] Preferably, the maximum irradiation power is 45.5KW.

[0037] As a possible design, the deflection voltage of the above laser-assisted sintering is -13 to -19 V, and the power is 17% of the maximum power.

[0038] Preferably, the above maximum power is 45.5KW.

[0039] As a possible design, the above cell was also checked by EL test (electroluminescence test) after laser assisted sintering process.

[0040] Example 1

[0041] A method for repairing a grid line failure of a battery cell comprises the following steps:

[0042] 50 cells with hidden grid lines were selected through EL test, and placed on a conveyor belt in a roller sintering furnace for drying and sintering. The belt speed was 2.8 m / min, the drying zone temperature of the sintering furnace was 400°C, and the upper temperature zone temperature of the sintering zone (sintering 1-sintering 11) of the sintering furnace was 510°C, and the lower temperature zone temperature was 450°C.

[0043] After sintering, light injection is carried out, and the irradiation power of light injection is 90%. The battery sheet is placed on a conveyor belt and passes through five temperature zones in sequence at a belt speed of 2.8m / min. The light injection temperature zone 1 is 620℃, the temperature zone 2 is 620℃, the temperature zone 3 is 570℃, the temperature zone 4 is 560℃, and the temperature zone 5 is 540℃, and then the temperature is lowered;

[0044] After light injection, laser-assisted sintering was performed with a deflection voltage of -16 V and a power of 17%.

[0045] Finally, the EL test is used to detect whether the grid line hidden part has been repaired.

[0046] As shown in Table 1, under the conditions of Example 1, the repair rate of the battery cell containing gate line defects is 64%.

[0047] Example 2

[0048] This embodiment is basically the same as Embodiment 1, except that the temperature of the upper temperature zone is 480°C, and the temperature of the lower temperature zone is 450°C.

[0049] A method for repairing a grid line failure of a battery cell comprises the following steps:

[0050] 45 cells with hidden grid lines were selected through EL test, and placed on a conveyor belt in a roller sintering furnace for drying and sintering in sequence. The belt speed was 2.8m / min, the temperature of the drying area of ​​the sintering furnace was 400℃, and the upper temperature zone of the sintering area (sintering 1-sintering 11) of the sintering furnace was 480℃, and the lower temperature zone was 450℃.

[0051] After sintering, light injection is carried out, and the irradiation power of light injection is 90%. The battery sheet is placed on a conveyor belt and passes through five temperature zones in sequence at a belt speed of 2.8m / min. The light injection temperature zone 1 is 620℃, the temperature zone 2 is 620℃, the temperature zone 3 is 570℃, the temperature zone 4 is 560℃, and the temperature zone 5 is 540℃, and then the temperature is lowered;

[0052] After light injection, laser-assisted sintering was performed with a deflection voltage of -16 V and a power of 17%.

[0053] Finally, the EL test is used to detect whether the grid line hidden part has been repaired.

[0054] As shown in Table 1, under the conditions of Example 2, the repair rate of the battery cell containing gate line defects is 67%.

[0055] Example 3

[0056] This embodiment is basically the same as Embodiment 1, except that the temperature of the upper temperature zone is 450°C and the temperature of the lower temperature zone is 450°C.

[0057] A method for repairing a grid line failure of a battery cell comprises the following steps:

[0058] 235 cells with hidden grid lines were selected through EL test, and placed on a conveyor belt in a roller sintering furnace for drying and sintering in sequence. The belt speed was 2.8m / min, the temperature of the drying area of ​​the sintering furnace was 400℃, and the temperature of the upper temperature zone of the sintering area (sintering 1-sintering 11) of the sintering furnace was 450℃, and the temperature of the lower temperature zone was 450℃.

[0059] After sintering, light injection is carried out, and the irradiation power of light injection is 90%. The battery sheet is placed on a conveyor belt and passes through five temperature zones in sequence at a belt speed of 2.8m / min. The light injection temperature zone 1 is 620℃, the temperature zone 2 is 620℃, the temperature zone 3 is 570℃, the temperature zone 4 is 560℃, and the temperature zone 5 is 540℃, and then the temperature is lowered;

[0060] After light injection, laser-assisted sintering was performed with a deflection voltage of -16 V and a power of 17%.

[0061] Finally, the EL test is used to detect whether the grid line hidden part has been repaired.

[0062] As shown in Table 1, under the conditions of Example 3, the repair rate of the battery cell containing gate line failure is 73%.

[0063] Example 4

[0064] A method for repairing a grid line failure of a battery cell comprises the following steps:

[0065] 40 cells with hidden grid lines were selected through EL test, and placed on a conveyor belt in a roller sintering furnace for drying and sintering in sequence. The belt speed was 1.8 m / min, the temperature of the drying area of ​​the sintering furnace was 350°C, and the upper temperature zone of the sintering area (sintering 1-sintering 11) of the sintering furnace was 510°C, and the lower temperature zone was 480°C.

[0066] After sintering, light injection is carried out, and the irradiation power of light injection is 90%. The battery sheet is placed on a conveyor belt and passes through five temperature zones in sequence at a belt speed of 1.8m / min. The light injection temperature zone 1 is 640℃, the temperature zone 2 is 640℃, the temperature zone 3 is 600℃, the temperature zone 4 is 580℃, and the temperature zone 5 is 560℃, and then the temperature is lowered;

[0067] After light injection, laser-assisted sintering was performed with a deflection voltage of -16 V and a power of 17%.

[0068] Finally, the EL test is used to detect whether the grid line hidden part has been repaired.

[0069] Example 5

[0070] A method for repairing a grid line failure of a battery cell comprises the following steps:

[0071] 55 cells with hidden grid lines were selected through EL test, and placed on a conveyor belt in a roller sintering furnace for drying and sintering in sequence. The belt speed was 3.8m / min, the temperature of the drying area of ​​the sintering furnace was 450℃, and the upper temperature zone of the sintering area (sintering 1-sintering 11) of the sintering furnace was 510℃, and the lower temperature zone was 420℃.

[0072] After sintering, light injection is carried out, and the irradiation power of light injection is 90%. The battery sheet is placed on a conveyor belt and passes through five temperature zones in sequence at a belt speed of 1.8m / min. The light injection temperature zone 1 is 600℃, the temperature zone 2 is 600℃, the temperature zone 3 is 550℃, the temperature zone 4 is 540℃, and the temperature zone 5 is 520℃, and then the temperature is lowered;

[0073] After light injection, laser-assisted sintering was performed with a deflection voltage of -16 V and a power of 17%.

[0074] Finally, the EL test is used to detect whether the grid line hidden part has been repaired.

[0075] Comparative Example 1

[0076] This comparative example is basically the same as Example 1, except that the temperature in the upper temperature zone is 540°C, and the temperature in the lower temperature zone is 510°C.

[0077] A method for repairing a grid line failure of a battery cell comprises the following steps:

[0078] 40 cells with hidden grid lines were selected through EL test, and placed on a conveyor belt in a roller sintering furnace for drying and sintering. The belt speed was 2.8 m / min, the drying zone temperature of the sintering furnace was 400°C, and the upper temperature zone temperature of the sintering zone (sintering 1-sintering 11) of the sintering furnace was 540°C, and the lower temperature zone temperature was 510°C.

[0079] After sintering, light injection is carried out, and the irradiation power of light injection is 90%. The battery sheet is placed on a conveyor belt and passes through five temperature zones in sequence at a belt speed of 2.8m / min. The light injection temperature zone 1 is 620℃, the temperature zone 2 is 620℃, the temperature zone 3 is 570℃, the temperature zone 4 is 560℃, and the temperature zone 5 is 540℃, and then the temperature is lowered;

[0080] After light injection, laser-assisted sintering was performed with a deflection voltage of -16 V and a power of 17%.

[0081] Finally, the EL test is used to detect whether the grid line hidden part has been repaired.

[0082] As shown in Table 1, under the conditions of Comparative Example 1, the repair rate of the battery cell containing grid line defects is 17%.

[0083] Comparative Example 2

[0084] This comparative example is basically the same as Example 1, except that the temperature in the upper temperature zone is 540°C, and the temperature in the lower temperature zone is 480°C.

[0085] A method for repairing a grid line failure of a battery cell comprises the following steps:

[0086] 30 cells with hidden grid lines were selected through EL test, and placed on a conveyor belt in a roller sintering furnace for drying and sintering in sequence. The belt speed was 2.8m / min, the temperature of the drying area of ​​the sintering furnace was 400℃, and the upper temperature zone of the sintering area (sintering 1-sintering 11) of the sintering furnace was 540℃, and the lower temperature zone was 480℃.

[0087] After sintering, light injection is carried out, and the irradiation power of light injection is 90%. The battery sheet is placed on a conveyor belt and passes through five temperature zones in sequence at a belt speed of 2.8m / min. The light injection temperature zone 1 is 620℃, the temperature zone 2 is 620℃, the temperature zone 3 is 570℃, the temperature zone 4 is 560℃, and the temperature zone 5 is 540℃, and then the temperature is lowered;

[0088] After light injection, laser-assisted sintering was performed with a deflection voltage of -16 V and a power of 17%.

[0089] Finally, the EL test is used to detect whether the grid line hidden part has been repaired.

[0090] As shown in Table 1, under the conditions of Comparative Example 1, the repair rate of the battery cell containing grid line hidden is 20%.

[0091] Comparative Example 3

[0092] This comparative example is basically the same as Example 1, except that the temperature in the upper temperature zone is 410°C.

[0093] A method for repairing a grid line failure of a battery cell comprises the following steps:

[0094] 50 cells with hidden grid lines were selected through EL test, and placed on a conveyor belt in a roller sintering furnace for drying and sintering in sequence. The belt speed was 2.8 m / min, the temperature of the drying area of ​​the sintering furnace was 400°C, and the upper temperature zone of the sintering area (sintering 1-sintering 11) of the sintering furnace was 410°C, and the lower temperature zone was 450°C.

[0095] After sintering, light injection is carried out, and the irradiation power of light injection is 90%. The battery sheet is placed on a conveyor belt and passes through five temperature zones in sequence at a belt speed of 2.8m / min. The light injection temperature zone 1 is 620℃, the temperature zone 2 is 620℃, the temperature zone 3 is 570℃, the temperature zone 4 is 560℃, and the temperature zone 5 is 540℃, and then the temperature is lowered;

[0096] After light injection, laser-assisted sintering was performed with a deflection voltage of -16 V and a power of 17%.

[0097] Finally, the EL test is used to detect whether the grid line hidden part has been repaired.

[0098] As shown in Table 1, under the conditions of Comparative Example 3, the repair rate of the battery cell containing gate line defects is 16%.

[0099] Comparative Example 4

[0100] This comparative example is basically the same as Example 1, except that the temperature in the lower temperature zone is 380°C.

[0101] A method for repairing a grid line failure of a battery cell comprises the following steps:

[0102] 60 cells with hidden grid lines were selected through EL test, and placed on a conveyor belt in a roller sintering furnace for drying and sintering in sequence. The belt speed was 2.8 m / min, the drying zone temperature of the sintering furnace was 400°C, and the upper temperature zone temperature of the sintering zone (sintering 1-sintering 11) of the sintering furnace was 510°C, and the lower temperature zone temperature was 380°C.

[0103] After sintering, light injection is carried out, and the irradiation power of light injection is 90%. The battery sheet is placed on a conveyor belt and passes through five temperature zones in sequence at a belt speed of 2.8m / min. The light injection temperature zone 1 is 620℃, the temperature zone 2 is 620℃, the temperature zone 3 is 570℃, the temperature zone 4 is 560℃, and the temperature zone 5 is 540℃, and then the temperature is lowered;

[0104] After light injection, laser-assisted sintering was performed with a deflection voltage of -16 V and a power of 17%.

[0105] Finally, the EL test is used to detect whether the grid line hidden part has been repaired.

[0106] As shown in Table 1, under the conditions of Comparative Example 4, the repair rate of the battery cell containing grid line hidden is 15%.

[0107] Comparative Example 5

[0108] This comparative example is basically the same as Example 1, except that the conveying speed during drying and sintering is 5.8 m / min.

[0109] A method for repairing a grid line failure of a battery cell comprises the following steps:

[0110] 55 cells with hidden grid lines were selected through EL test. The cells were placed on a conveyor belt in a roller sintering furnace for drying and sintering. The belt speed was 5.8m / min. The temperature of the drying area of ​​the sintering furnace was 400℃. The upper temperature zone of the sintering area (sintering 1-sintering 11) of the sintering furnace was 510℃, and the lower temperature zone was 450℃.

[0111] After sintering, light injection is carried out, and the irradiation power of light injection is 90%. The battery sheet is placed on a conveyor belt and passes through five temperature zones in sequence at a belt speed of 2.8m / min. The light injection temperature zone 1 is 620℃, the temperature zone 2 is 620℃, the temperature zone 3 is 570℃, the temperature zone 4 is 560℃, and the temperature zone 5 is 540℃, and then the temperature is lowered;

[0112] After light injection, laser-assisted sintering was performed with a deflection voltage of -16 V and a power of 17%.

[0113] Finally, the EL test is used to detect whether the grid line hidden part has been repaired.

[0114] As shown in Table 1, under the conditions of Comparative Example 5, the repair rate of the battery cell containing gate line defects is 36.4%.

[0115] Comparative Example 6

[0116] This comparative example is basically the same as Example 1, except that: the light injection temperature zone 1 is 550°C, the temperature zone 2 is 550°C, the temperature zone 3 is 500°C, the temperature zone 4 is 490°C, and the temperature zone 5 is 480°C.

[0117] A method for repairing a grid line failure of a battery cell comprises the following steps:

[0118] 50 cells with hidden grid lines were selected through EL test, and placed on a conveyor belt in a roller sintering furnace for drying and sintering in sequence. The belt speed was 5.8m / min, the temperature of the drying area of ​​the sintering furnace was 400℃, and the upper temperature zone of the sintering area (sintering 1-sintering 11) of the sintering furnace was 510℃, and the lower temperature zone was 450℃.

[0119] After sintering, light injection is carried out, and the irradiation power of light injection is 90%. The battery sheet is placed on a conveyor belt and passes through five temperature zones in sequence at a belt speed of 2.8m / min. The light injection temperature zone 1 is 550℃, the temperature zone 2 is 550℃, the temperature zone 3 is 500℃, the temperature zone 4 is 490℃, and the temperature zone 5 is 480℃, and then the temperature is lowered;

[0120] After light injection, laser-assisted sintering was performed with a deflection voltage of -16 V and a power of 17%.

[0121] Finally, the EL test is used to detect whether the grid line hidden part has been repaired.

[0122] As shown in Table 1, under the conditions of Comparative Example 6, the repair rate of the battery cell containing gate line defects is 52%.

[0123] Table 1

[0124] Before repair Before repair Before repair After Repair Before repair Before repair Sample Number of cells (pcs) Number of hidden grid lines (pieces) Proportion Number of cells (pcs) Number of hidden grid lines (pieces) Proportion Repair rate Example 1 50 50 100% 50 18 36% 64% Example 2 45 45 100% 45 15 33% 67% Example 3 235 235 100% 235 63 27% 73% Comparative Example 1 40 40 100% 40 33 83% 17% Comparative Example 2 30 30 100% 30 24 80% 20% Comparative Example 3 50 50 100% 50 42 84% 16% Comparative Example 4 60 60 100% 60 51 85% 15% Comparative Example 5 55 55 100% 55 35 63.6% 36.4% Comparative Example 6 50 50 100% 50 24 48% 52%

[0125] From Table 1, it can be seen that during sintering, if the sintering temperature of the upper temperature zone / lower temperature zone is too high or too low, it will affect the repair rate, and if the transmission speed is too fast, it will also reduce the repair effect. In addition, the temperature change of light injection will also have a certain impact on the repair effect.

[0126] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for repairing grid line failure of a cell, characterized in that: The steps include: The cell with gate line hidden is subjected to sintering, light injection and laser assisted sintering treatments in sequence; The battery cell is also dried before sintering, and the drying is carried out on a conveyor belt with a drying belt speed of 1.8 to 3.8 m / min; The sintering is specifically to place the battery cell in a sintering furnace for sintering. During sintering, the temperature of the upper temperature zone is 450-510°C and the temperature of the lower temperature zone is 420-480°C. During sintering, the battery cell is placed on a conveyor belt, and the sintering belt speed is 1.8-3.8 m / min. The light injection annealing treatment is divided into five temperature zones, with the temperature of temperature zone 1 being 600-640°C, the temperature of temperature zone 2 being 600-640°C, the temperature of temperature zone 3 being 550-600°C, the temperature of temperature zone 4 being 540-580°C, and the temperature of temperature zone 5 being 520-560°C.

2. The method for repairing grid line failure of a cell according to claim 1, characterized in that: The drying treatment temperature is 350-450°C.

3. The method for repairing grid line failure of a cell according to claim 1, characterized in that: During the light injection, the cell is placed on a conveyor belt and passes through five temperature zones in sequence at a belt speed of 1.8 to 3.8 m / min, and then cooled.

4. The method for repairing grid line failure of a cell according to claim 1, characterized in that: The irradiation power of the light injection is 90%.

5. The method for repairing grid line failure of a cell according to claim 1, characterized in that: The deflection voltage of the laser-assisted sintering is -13 to -19 V, and the power is 17%.

6. The method for repairing grid line failure of a cell according to claim 1, characterized in that: The cells were also inspected by EL testing after the laser assisted sintering process.

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