Battery piece testing method

Abstract

The invention discloses a battery piece test method, which comprises the following steps of: performing electrical performance test on a battery piece to obtain a first test result; a photovoltaic sample piece is prepared based on the battery piece, and the photovoltaic sample piece comprises a first protection piece, a first adhesive film, the battery piece, a second adhesive film and a second protection piece which are sequentially stacked; performing a potential-induced degradation test on the photovoltaic sample piece; after the potential induced degradation test is completed, taking out the battery piece in the photovoltaic sample piece, and carrying out the electrical performance test on the battery piece again to obtain a second test result; and according to the first test result and the second test result, determining the anti-potential-induced-degradation performance of the battery piece. In the embodiment of the invention, the components in the photovoltaic sample piece are not connected, so that after the PID test of the photovoltaic sample piece is completed, the components in the photovoltaic sample piece can be completely separated, and the battery piece in the photovoltaic sample piece can be rapidly and completely taken out to test the PID resistance of the battery piece.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to a cell testing method. Background Art

[0002] PID (Potential Induced Degradation) refers to the phenomenon in which solar cells experience power degradation when subjected to a certain external voltage for a long period of time. PID is a major cause of power loss in photovoltaic modules.

[0003] Currently, during PID testing, photovoltaic modules are placed in an environmental chamber and connected to a high-voltage power supply, which is used to provide the voltage required for the PID test.

[0004] However, since the PID test is performed on finished photovoltaic modules, the film in the photovoltaic modules is bonded to the cells and glass. Therefore, after the test is completed, only the entire photovoltaic module can be analyzed, and the anti-PID performance of the cell itself cannot be tested. Summary of the Invention

[0005] The present invention provides a cell testing method, which aims to at least solve the technical problem in the prior art that after the PID test is completed, only the entire photovoltaic module can be analyzed, and the anti-PID performance of the cell itself cannot be tested.

[0006] An embodiment of the present invention provides a battery cell testing method, comprising:

[0007] Performing an electrical performance test on the battery cell to obtain a first test result;

[0008] Prepare a photovoltaic sample based on the cell, wherein the photovoltaic sample includes a first protective member, a first adhesive film, the cell, a second adhesive film, and a second protective member stacked in sequence;

[0009] Performing a potential induced degradation test on the photovoltaic sample;

[0010] After the potential induced degradation test is completed, the solar cell in the photovoltaic sample is taken out and the electrical performance test of the solar cell is performed again to obtain a second test result;

[0011] The potential induced degradation resistance of the battery cell is determined according to the first test result and the second test result.

[0012] Optionally, after preparing a photovoltaic sample based on the solar cell and before performing a potential induced degradation test on the photovoltaic sample, the method further includes:

[0013] placing a pressurizing module on the photovoltaic sample, wherein the pressurizing module is used to provide downward pressure to the photovoltaic sample;

[0014] The performing of a potential induced degradation test on the photovoltaic sample comprises:

[0015] A potential induced degradation test is performed on the photovoltaic sample with the pressurized module placed thereon.

[0016] Optionally, the first adhesive film and the second adhesive film are cross-linked and cured adhesive films obtained by heat pressing;

[0017] And / or, the cell is a back contact cell.

[0018] Optionally, before performing an electrical performance test on the battery cell and obtaining a first test result, the method further includes:

[0019] Providing a battery cell, a plurality of cell connectors, and two lead-out members, and connecting the battery cell to the two lead-out members through the plurality of cell connectors, wherein the two lead-out members have opposite conductivity types;

[0020] The step of performing an electrical performance test on the battery cell to obtain a first test result includes:

[0021] An electrical performance test is performed on the battery cell using a connection assembly including a plurality of the cell connectors and two lead-out members to obtain a first test result.

[0022] Optionally, after performing an electrical performance test on the cell to obtain a first test result and before preparing a photovoltaic sample based on the cell, the process further includes:

[0023] Providing a short-circuit component, and connecting the two lead-out components via the short-circuit component;

[0024] providing a first protective member and a second protective member;

[0025] The method of preparing a photovoltaic sample based on the solar cell comprises:

[0026] The first protective member, the cured first adhesive film, the solar cell connected with the connecting assembly and the short-circuit member, the cured second adhesive film and the second protective member are stacked in sequence to form a photovoltaic sample.

[0027] Optionally, after the potential induced degradation test is completed, the cells in the photovoltaic sample are taken out and the electrical performance test of the cells is performed again to obtain a second test result, including:

[0028] After the potential induced degradation test is completed, the solar cell connected with the connection assembly and the short-circuit component is taken out from the photovoltaic sample;

[0029] Remove the shorting piece;

[0030] The electrical performance of the battery cell is tested again through the connection assembly to obtain a second test result.

[0031] Optionally, the pressurizing module covers the front surface of the photovoltaic sample, and the pressure on the photovoltaic sample is greater than or equal to 5000N / m 2 .

[0032] Optionally, the cross-linking degree of the first adhesive film after curing and the cross-linking degree of the second adhesive film after curing are both greater than or equal to 75%.

[0033] Optionally, after preparing a photovoltaic sample based on the solar cell and before placing a pressurizing module on the photovoltaic sample, the method further includes:

[0034] placing a first electrode and a second electrode on the front and back of the photovoltaic sample respectively;

[0035] Placing a pressurizing module on the photovoltaic sample comprises:

[0036] A pressurizing module is placed on the first electrode.

[0037] Optionally, performing a potential induced degradation test on the photovoltaic sample with the pressurized module placed thereon comprises:

[0038] placing the photovoltaic sample with the pressurized module in an environmental chamber;

[0039] Providing a test power supply, wherein the absolute value of the voltage output by the test power supply is greater than or equal to 1500V;

[0040] The solar cell and the first electrode in the photovoltaic sample are connected to the test power supply, and the test power supply is turned on for a set time.

[0041] Optionally, determining the resistance to potential induced degradation of the battery cell according to the first test result and the second test result includes:

[0042] Comparing the EL images and / or current-voltage curves of the cell in the first test result and the second test result to determine the anti-potential induced degradation performance of the cell;

[0043] And / or, comparing the difference between the second test result and the first test result to determine the anti-potential induced degradation performance of the battery cell.

[0044] In the embodiment of the present invention, there is no connection between the various components in the photovoltaic sample. Therefore, after the PID test of the photovoltaic sample is completed, the various components in the photovoltaic sample can be completely separated, so that the battery cells can be quickly and completely removed to test the anti-PID performance of the battery cells themselves. In addition, compared with the use of laminated photovoltaic modules for testing, the various components in the photovoltaic sample are stacked and not laminated, which saves the time required for the lamination process and thus shortens the sample preparation cycle and the testing cycle. In addition, the PID test is targeted at photovoltaic samples, that is, before the finished photovoltaic modules are prepared, the PID failure risk of the photovoltaic sample can be identified in advance, thereby improving R&D efficiency. In addition, the first film, the second film, the first protective member and the second protective member separated after the PID test are completed can also be analyzed separately, thereby effectively helping testers to perform failure analysis or abnormality analysis and reducing the difficulty of analysis for testers.

[0045] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A flowchart of a cell testing method according to an embodiment of the present invention;

[0047] Figure 2 A flowchart of another cell testing method provided by an embodiment of the present invention;

[0048] Figure 3 A schematic structural diagram of a battery cell connected to a connection assembly according to an embodiment of the present invention;

[0049] Figure 4 A schematic structural diagram of a battery cell connected to a connection assembly and a short-circuit member provided in an embodiment of the present invention;

[0050] Figure 5 A schematic diagram of the stacked structure of a photovoltaic sample provided by an embodiment of the present invention;

[0051] Figure 6 A schematic structural diagram of a pressurizing module, a first electrode, a photovoltaic sample, a second electrode, and a test power supply provided in an embodiment of the present invention.

[0052] Reference numerals:

[0053] 1-first protective member, 2-first adhesive film, 3-battery cell, 4-second adhesive film, 5-second protective member, 6-pressurization module, 7-first electrode, 8-second electrode, 9-connector, 10-lead-out member, 11-short-circuit member, 12-test power supply. DETAILED DESCRIPTION

[0054] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0055] The direct harm of PID to photovoltaic modules is that a large amount of electric charge accumulates on the surface of the battery cell, which aggravates the passivation effect of the battery cell surface, thereby reducing the fill factor, open circuit voltage and short circuit current of the battery cell, and attenuating the power of the photovoltaic module. At present, during the PID test, the photovoltaic module is placed in an environmental chamber, and the photovoltaic module is connected to a high-voltage power supply, which is used to provide the voltage required for the PID test. However, since the finished photovoltaic module is used for the PID test, the adhesive film in the photovoltaic module is bonded to the battery cell and glass. After the test is completed, only the entire photovoltaic module can be analyzed, and the anti-PID performance of the battery cell itself cannot be tested. In addition, the photovoltaic module includes multiple battery strings and needs to go through a lamination process. The process is cumbersome and the sample preparation cycle and test cycle are long. In order to solve the above problems, an embodiment of the present invention discloses a battery cell testing method.

[0056] Reference Figure 1 , an embodiment of the present invention discloses a battery cell testing method, comprising:

[0057] Step 101: perform an electrical performance test on the battery cell to obtain a first test result.

[0058] For example, the cell may be a crystalline silicon cell. The electrical performance test may be an EL (electroluminescence) test and / or an IV (current-voltage) test. The EL test may be performed using an EL tester, and the test result obtained by the EL test is an EL image. The IV test may be performed using an IV tester, and the test result obtained by the IV test is a current-voltage curve. The first test result includes the EL image and / or the current-voltage curve.

[0059] Optionally, during the EL test, the cell is placed in an environmental aging test chamber, which is a lightless environment with no polluted gas inside. Optionally, the relative humidity in the environmental aging test chamber is 40%±5%, and the temperature is 60±2°C. The lens of the camera in the EL tester has a filtering function, and the test accuracy of the camera is better than or equal to 0.8mm / pixel. During the EL test, the high current detection time is less than or equal to 10 seconds, and the low current detection time is less than or equal to 15 seconds. The current values ​​of high current and low current can be adjusted according to actual needs. The resolution of the display in the EL tester is greater than or equal to 4K.

[0060] Optionally, during IV testing, the following requirements can be met: illumination uniformity <±2% (Class A level), long-term illumination instability <±0.5% (Class A level), spectral mismatch (AM1.5G) <±12.5%; test repeatability ≤0.5%.

[0061] It should be understood that the test environment involved in this application is an example or preferred value and should not limit the scope of protection of this application.

[0062] Step 102: Prepare photovoltaic samples based on the solar cells.

[0063] Reference Figure 5 The photovoltaic sample includes a first protective member 1, a first adhesive film 2, a solar cell 3, a second adhesive film 4, and a second protective member 5, which are stacked in sequence. There is no connection between the various components in the photovoltaic sample, that is, there is no connection between the first protective member 1, the first adhesive film 2, the solar cell 3, the second adhesive film 4, and the second protective member 5. Therefore, after the PID test of the photovoltaic sample is completed, the various components in the photovoltaic sample can be completely separated, facilitating failure analysis by testers.

[0064] The first protective member 1 can be glass or a photovoltaic backsheet. The second protective member 5 is glass. The length and width of the first protective member 1 are equal to those of the second protective member 5. The first and second adhesive films 2 and 4 can be made of POE (PolyOlefin Elastomer, a copolymer of ethylene and higher α-olefins) or EVA (Ethylene Vinyl Acetate, an ethylene-vinyl acetate copolymer). The length and width of the first adhesive film 2 are equal to those of the second adhesive film 4.

[0065] The photovoltaic sample includes at least one complete cell 3, which may include multiple cell slices connected by multiple cell connectors 9. The photovoltaic sample preferably includes one complete cell 3, which preferably includes two cell slices. Compared to photovoltaic modules that include multiple cell strings, in embodiments of the present invention, the photovoltaic sample only needs to include at least one complete cell 3, resulting in a simpler structure and a shorter sample preparation cycle. The cell 3 may be a back-contact cell.

[0066] Step 103: Perform a potential induced degradation test on the photovoltaic sample.

[0067] Optionally, when performing a PID test, the photovoltaic sample is placed in an environmental chamber and connected to a test power supply. The environmental chamber is a lightless environment with no contaminated gases inside. The relative humidity within the environmental chamber is 40% ± 5%, and the temperature is 60 ± 2°C. The test power supply is used to provide the voltage required for the PID test of the photovoltaic sample. The test power supply is specifically a DC power supply, and the absolute value of the voltage output by the test power supply is greater than or equal to 1500V. The absolute value of the voltage output by the test power supply is preferably 2000V.

[0068] Step 104: After the potential induced degradation test is completed, the solar cells in the photovoltaic sample are taken out and the electrical performance test of the solar cells is performed again to obtain a second test result.

[0069] Specifically, after the PID test is completed, the photovoltaic sample is removed from the environmental chamber. The components within the photovoltaic sample are then disassembled and the cells removed. The process for performing another electrical performance test on the cells is identical to the process performed in step 101. The second test results also include an EL image and / or a current-voltage curve.

[0070] Step 105 : Determine the potential induced degradation resistance of the battery cell according to the first test result and the second test result.

[0071] Specifically, determining the potential-induced degradation resistance of the cell based on the first and second test results includes: comparing the EL images and / or current-voltage curves of the cell in the first and second test results to determine the potential-induced degradation resistance of the cell; and / or comparing the difference between the second test result and the first test result to determine the potential-induced degradation resistance of the cell. Both the first and second test results include EL images and / or current-voltage curves. Comparing the EL images and / or current-voltage curves of the cell before and after the PID test to assess the cell's PID resistance. After the PID test, the smaller the difference between the second test result and the first test result, the better the cell's PID resistance.

[0072] After step 105, the following steps may be performed: removing the first adhesive film 2, the second adhesive film 4, the first protective member 1, and the second protective member 5 from the photovoltaic sample; and analyzing each of the first adhesive film 2, the second adhesive film 4, the first protective member 1, and the second protective member 5. After the PID resistance performance test of the solar cell itself is completed, the first adhesive film 2, the second adhesive film 4, the first protective member 1, and the second protective member 5 that have been removed can also be analyzed individually to comprehensively evaluate the PID resistance performance of the photovoltaic sample.

[0073] In the embodiment of the present invention, there is no connection between the various components in the photovoltaic sample. Therefore, after the PID test of the photovoltaic sample is completed, the various components in the photovoltaic sample can be completely separated, so that the battery cells therein can be quickly and completely removed to test the anti-PID performance of the battery cells themselves. In addition, compared with the use of laminated photovoltaic modules for testing, the various components in the photovoltaic sample are stacked and not laminated, which saves the time required for the lamination process and thus shortens the sample preparation cycle and the testing cycle. In addition, the PID test is targeted at photovoltaic samples, that is, before the finished photovoltaic modules are prepared, the PID failure risk of the photovoltaic sample can be identified in advance, thereby improving R&D efficiency. In addition, the first adhesive film 2, the second adhesive film 4, the first protective member 1 and the second protective member 5 separated after the PID test are completed can also be analyzed separately, thereby effectively helping testers to perform failure analysis or abnormality analysis and reducing the difficulty of analysis for testers.

[0074] Reference Figure 2 and Figure 6 After preparing a photovoltaic sample based on the solar cell in step 102, and before performing a potential induced degradation test on the photovoltaic sample in step 103, the method further includes:

[0075] Step 111: placing a pressurizing module on the photovoltaic sample.

[0076] The pressure module 6 is used to provide downward pressure to the photovoltaic sample, and the direction of the downward pressure is consistent with the direction in which the second protective member 5 points to the first protective member 1. The pressure provided by the pressure module 6 to the photovoltaic sample can be greater than or equal to 5000N / m 2 .

[0077] Step 103 , performing a potential induced degradation test on the photovoltaic sample, includes: step 1031 , performing a potential induced degradation test on the photovoltaic sample with the pressurized module placed thereon.

[0078] During the PID test, the pressurizing device remains in place on the photovoltaic sample. The downward pressure applied to the photovoltaic sample by the pressurizing module 6 ensures close contact between the various components within the photovoltaic sample, allowing the pressurized photovoltaic sample to more closely conform to the actual conditions of the laminated photovoltaic module, thereby improving test accuracy.

[0079] Reference Figure 2 , step 102, before preparing a photovoltaic sample based on the solar cell, it also includes: step 109, providing a first adhesive film and a second adhesive film.

[0080] The first and second adhesive films are both cross-linked and cured films obtained through hot pressing. During normal photovoltaic module production, the films within the module undergo cross-linking and curing after the lamination process. The temperature and pressure of the hot pressing of the first and second films can be consistent with the temperature and pressure of the lamination process to ensure that the properties of the cured first and second films 2 and 4 are as consistent as possible with those of the films in the laminated photovoltaic module. This ensures that the photovoltaic sample is more closely aligned with the actual photovoltaic module and provides more accurate test results.

[0081] Reference Figure 2 and Figure 3 Step 101, performing an electrical performance test on the battery cell, before obtaining a first test result, further includes:

[0082] Step 106 : providing a battery cell, a plurality of cell connectors, and two lead-out members, and connecting the battery cell to the two lead-out members through the plurality of cell connectors.

[0083] Optionally, the battery cell 3 is located between two lead-out members 10, and the two lead-out members 10 have opposite conductivity types, wherein one lead-out member 10 has a positive polarity and the other lead-out member 10 has a negative polarity, and the two lead-out members 10 are used to lead out the positive and negative electrodes of the battery cell 3, respectively. The sheet connector can be a welding strip, which is welded to the lead-out member 10, and the welding strip is welded to the main grid on the battery cell 3. The lead-out member 10 with positive polarity is connected to multiple welding strips connected to the positive main grid, and the lead-out member 10 with negative polarity is connected to multiple welding strips connected to the negative main grid. For back-contact battery cells, the welding strip is connected to the back of the back-contact battery cell.

[0084] Step 101, performing an electrical performance test on the battery cell to obtain a first test result, includes: step 1011, performing an electrical performance test on the battery cell through a connection assembly including multiple cell connectors and two lead-out members to obtain a first test result.

[0085] When performing an EL test on a cell, an external power source is connected via the two lead-out members 10 in the connector assembly. When performing an IV test on a cell, an external load is connected via the two lead-out members 10. In this embodiment of the present invention, the positive and negative electrodes of the cell 3 can be led out via the two lead-out members 10 in the connector assembly for all different cell types. This allows the test method to be adapted to test different cell types, such as back-contact cells, broadening the test range.

[0086] Reference Figure 2 and Figure 4 In step 101, after performing an electrical performance test on the cell and obtaining a first test result, in step 102, before preparing a photovoltaic sample based on the cell, the method further includes:

[0087] Step 107: Provide a short-circuit component and connect the two lead-out components via the short-circuit component.

[0088] The short-circuit 11 is electrically connected to the lead-out member 10 , and the connection between the short-circuit 11 and the lead-out member 10 can be welding. The short-circuit 11 is used to short-circuit the two lead-out members 10 to short-circuit the positive and negative electrodes of the battery cell 3 .

[0089] Step 108: Provide a first protective member and a second protective member.

[0090] Step 102, preparing a photovoltaic sample based on the solar cell, includes:

[0091] Step 1021 , stacking the first protective member, the cured first adhesive film, the solar cell connected with the connection assembly and the short-circuit member, the cured second adhesive film and the second protective member in sequence to form a photovoltaic sample.

[0092] In the photovoltaic sample, the stacking order from bottom to top is respectively the first protective member 1, the first adhesive film 2 after curing, the battery cell 3 connected with the connecting assembly and the short-circuit 11, the second adhesive film 4 after curing and the second protective member 5. In this photovoltaic sample, the battery cell 3 is connected with the connecting assembly and the short-circuit 11, and the positive and negative poles of the battery cell 3 are short-circuited by the short-circuit 11. During the PID test, one pole of the test power supply 12 is connected to the short-circuit 11, so that the test power supply 12 can be connected to the short-circuited battery cell. By setting the short-circuit 11, the battery cell after the electrical performance test can be quickly short-circuited to facilitate the subsequent PID test, and when the electrical performance test of the battery cell is performed again, it is only necessary to remove the short-circuit 11.

[0093] Reference Figure 2 In step 104, after the potential induced degradation test is completed, the cells in the photovoltaic sample are removed and the electrical performance test of the cells is performed again to obtain a second test result, including:

[0094] Step 1041, after the potential induced degradation test is completed, the solar cell connected to the connection component and the short-circuit component in the photovoltaic sample is removed; Step 1042, the short-circuit component is removed; Step 1043, the electrical performance test of the solar cell is performed again through the connection component to obtain a second test result.

[0095] Specifically, after the potential induced degradation test is completed, the photovoltaic sample is taken out from the environmental chamber, and then the stacked structure in the photovoltaic sample is disassembled, and the battery cell 3 connected with the connecting component and the short-circuit 11 is taken out. Then, the short-circuit 11 is removed, and the battery cell 3 connected with the connecting component remains. The electrical performance of the battery cell is tested again through the connecting component to obtain a second test result.

[0096] The pressure module 6 covers the front of the photovoltaic sample, and the pressure on the photovoltaic sample is greater than or equal to 5000N / m 2 .

[0097] Specifically, the front side of the photovoltaic sample is also the light-facing side of the photovoltaic sample. The cross-sectional area of ​​the pressurizing module 6 is greater than or equal to the cross-sectional area of ​​the photovoltaic sample. The cross-sectional area of ​​the pressurizing module 6 is also the cross-sectional area perpendicular to the thickness direction of the pressurizing module 6. The cross-sectional area of ​​the photovoltaic sample is also the cross-sectional area perpendicular to the thickness direction of the photovoltaic sample. The cross-sectional area of ​​the pressurizing module 6 is preferably equal to the cross-sectional area of ​​the photovoltaic sample. At this time, the length and width of the pressurizing module 6 are respectively equal to the length and width of the second protective member 5. When the pressurizing module 6 covers the front side of the photovoltaic sample, it can ensure that every part of the photovoltaic sample is subjected to downward pressure, thereby ensuring that the photovoltaic sample is uniformly stressed. The pressure exerted on the photovoltaic sample is greater than or equal to 5000N / m 2 When the photovoltaic sample is in close contact with each other, it can ensure that the various components in the photovoltaic sample are in close contact.

[0098] The crosslinking degree of the first adhesive film 2 after curing and the crosslinking degree of the second adhesive film 4 after curing are both greater than or equal to 75%.

[0099] The degree of crosslinking of the adhesive film in the laminated photovoltaic module is greater than or equal to 75%. In the embodiment of the present invention, the degree of crosslinking of the cured first adhesive film 2 and the cured second adhesive film 4 are both greater than or equal to 75%, consistent with the degree of crosslinking of the adhesive film in the photovoltaic module, thereby making the photovoltaic sample more suitable for the actual photovoltaic module.

[0100] Reference Figure 2 and Figure 6 , step 102, after preparing a photovoltaic sample based on the solar cell, step 111, before placing a pressurizing module on the photovoltaic sample, further comprising: step 110, placing a first electrode and a second electrode on the front and back of the photovoltaic sample respectively.

[0101] The photovoltaic sample is located between the first electrode 7 and the second electrode 8. The material of the first electrode 7 and the material of the second electrode 8 are both metal materials with good electrical conductivity. The first electrode 7 is used to connect to the test power supply 12. When the first electrode 7 is connected to the test power supply 12, it can simulate the situation where a high-intensity negative voltage is applied to the front of the photovoltaic sample. The length and width of the first electrode 7 are equal to the length and width of the second protective member 5, respectively, and the length and width of the second electrode 8 are equal to the length and width of the first protective member 1, respectively, to ensure that the voltage can be evenly applied to the first electrode 7 and the second electrode 8 during the PID test.

[0102] Step 111 , placing a pressurizing module on the photovoltaic sample, includes: step 1111 , placing a pressurizing module on the first electrode.

[0103] After the photovoltaic sample is prepared, the first electrode 7 and the second electrode 8 are placed on the photovoltaic sample. Then, the pressurizing module 6 is placed on the first electrode 7 so that the pressurizing module 6 can apply downward pressure to the photovoltaic sample through the first electrode 7. The second electrode 8, photovoltaic sample, first electrode 7, and pressurizing module 6 are stacked in the following order from bottom to top: second electrode 8, photovoltaic sample, first electrode 7, and pressurizing module 6.

[0104] Step 1031, performing a potential induced degradation test on the photovoltaic sample with the pressurized module placed therein, including: placing the photovoltaic sample with the pressurized module placed therein into an environmental chamber; providing a test power supply; connecting the cell and the first electrode in the photovoltaic sample to the test power supply, turning on the test power supply, and continuing for a set time.

[0105] Specifically, before turning on the test power supply, first determine whether the temperature of the environmental chamber has reached the set temperature value and whether the humidity of the environmental chamber has reached the set humidity value; if so, turn on the test power supply. The set temperature value can be 60±2°C, and the set humidity value can be 40%±5%.

[0106] One terminal of the test power supply 12 is connected to the battery cell 3 via a shorting member 11, and the other terminal of the test power supply 12 is connected to the first electrode 7 or the second electrode 8. The other terminal of the test power supply 12 is preferably connected to the first electrode 7. The test power supply 12 is a DC power supply, and the absolute value of the voltage output by the test power supply 12 is greater than or equal to 1500V. The absolute value of the voltage output by the test power supply 12 is preferably 2000V.

[0107] Reference Figure 6 When the test power supply 12 applies a reverse voltage, the positive electrode of the test power supply 12 is connected to the first electrode 7, and the negative electrode of the test power supply 12 is connected to the short-circuit component 11. The voltage output by the test power supply 12 is a negative value, for example, a voltage of -2000V is output.

[0108] When the test power supply 12 applies a forward voltage, the positive pole of the test power supply 12 can be connected to the short-circuit 11, and the negative pole of the test power supply 12 can be connected to the first electrode 7. The voltage output by the test power supply 12 is a positive value, for example, a voltage of 2000V is output.

[0109] In other embodiments, when the test power supply 12 applies a forward voltage, the positive electrode of the test power supply 12 can be connected to the second electrode 8 , and the negative electrode of the test power supply 12 can be connected to the short-circuit 11 .

[0110] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0111] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A battery cell testing method, characterized in that: include: Performing an electrical performance test on the battery cell to obtain a first test result; Prepare a photovoltaic sample based on the cell, wherein the photovoltaic sample includes a first protective member, a first adhesive film, the cell, a second adhesive film, and a second protective member stacked in sequence; Performing a potential induced degradation test on the photovoltaic sample; After the potential induced degradation test is completed, the solar cell in the photovoltaic sample is taken out and the electrical performance test of the solar cell is performed again to obtain a second test result; The potential induced degradation resistance of the battery cell is determined according to the first test result and the second test result.

2. The cell testing method according to claim 1, wherein: After preparing a photovoltaic sample based on the cell and before performing a potential induced degradation test on the photovoltaic sample, the method further includes: placing a pressurizing module on the photovoltaic sample, wherein the pressurizing module is used to provide downward pressure to the photovoltaic sample; The performing of a potential induced degradation test on the photovoltaic sample comprises: A potential induced degradation test is performed on the photovoltaic sample with the pressurized module placed thereon.

3. The cell testing method according to claim 1 or 2, characterized in that: The first adhesive film and the second adhesive film are cross-linked and cured adhesive films obtained by heat pressing; And / or, the cell is a back contact cell.

4. The cell testing method according to claim 1, wherein: Before performing an electrical performance test on the battery cell and obtaining a first test result, the method further includes: Providing a battery cell, a plurality of cell connectors, and two lead-out members, and connecting the battery cell to the two lead-out members through the plurality of cell connectors, wherein the two lead-out members have opposite conductivity types; The step of performing an electrical performance test on the battery cell to obtain a first test result includes: An electrical performance test is performed on the battery cell using a connection assembly including a plurality of the cell connectors and two lead-out members to obtain a first test result.

5. The cell testing method according to claim 4, wherein: After performing an electrical performance test on the cell to obtain a first test result and before preparing a photovoltaic sample based on the cell, the method further includes: Providing a short-circuit component, and connecting the two lead-out components via the short-circuit component; providing a first protective member and a second protective member; The method of preparing a photovoltaic sample based on the solar cell comprises: The first protective member, the cured first adhesive film, the solar cell connected with the connecting assembly and the short-circuit member, the cured second adhesive film and the second protective member are stacked in sequence to form a photovoltaic sample.

6. The cell testing method according to claim 5, characterized in that: After the potential induced degradation test is completed, the cells in the photovoltaic sample are removed and the electrical performance test of the cells is performed again to obtain a second test result, including: After the potential induced degradation test is completed, the solar cell connected with the connection assembly and the short-circuit component is taken out from the photovoltaic sample; Remove the short-circuit component; The electrical performance of the battery cell is tested again through the connection assembly to obtain a second test result.

7. The cell testing method according to claim 2, wherein: The pressurizing module covers the front of the photovoltaic sample, and the pressure on the photovoltaic sample is greater than or equal to 5000N / m 2 .

8. The cell testing method according to claim 3, wherein: The crosslinking degree of the first adhesive film after curing and the crosslinking degree of the second adhesive film after curing are both greater than or equal to 75%.

9. The cell testing method according to claim 2, wherein: After preparing the photovoltaic sample based on the solar cell and before placing a pressurizing module on the photovoltaic sample, the method further includes: placing a first electrode and a second electrode on the front and back of the photovoltaic sample respectively; Placing a pressurizing module on the photovoltaic sample comprises: A pressurizing module is placed on the first electrode.

10. The cell testing method according to claim 9, wherein: The method of performing a potential induced degradation test on the photovoltaic sample having the pressurized module placed thereon comprises: placing the photovoltaic sample with the pressurized module in an environmental chamber; Providing a test power supply, wherein the absolute value of the voltage output by the test power supply is greater than or equal to 1500V; The solar cell and the first electrode in the photovoltaic sample are connected to the test power supply, and the test power supply is turned on for a set time.

11. The cell testing method according to claim 1, wherein: Determining the anti-potential induced degradation performance of the battery cell according to the first test result and the second test result includes: Comparing the EL images and / or current-voltage curves of the cell in the first test result and the second test result to determine the anti-potential induced degradation performance of the cell; And / or, comparing the difference between the second test result and the first test result to determine the anti-potential induced degradation performance of the battery cell.

Images